JP2736975B2 - Method for producing polymerized toner for developing electrostatic images - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for developing an electrostatic image in an image forming method such as electrophotography, electrostatography, and electrostatic printing. More particularly, the present invention relates to an improved method for producing a polymerized toner for developing electrostatic images by a suspension polymerization method having a granulation step for efficiently forming particles having a sharp particle size distribution.

[Related Art] Toners for visualizing an electric or magnetic latent image or the like are used in various processes for forming and recording an image.

As an electrophotographic method which is one of such image forming processes, many methods are known as described in, for example, US Pat. No. 2,297,691. In this electrophotography, generally, photoconductive materials are used,
An electric latent image was formed on the photoreceptor by various means, and then the latent image was developed using toner to form a toner image, and this toner image was transferred to a transfer material such as paper as necessary. Thereafter, the copy is obtained by fixing the toner image to the transfer material or the like by using heat, pressure, solvent vapor, or the like.
Further, as a method of developing using a toner or a method of fixing a toner image, various methods have been conventionally proposed, and a method suitable for each image forming process is adopted.

[Problems to be Solved by the Invention] Conventionally, a toner used for the above-mentioned purpose is generally prepared by melting and mixing a coloring agent composed of a dye and a pigment in a thermoplastic resin and uniformly dispersing the coloring agent. It has been produced as a toner having a desired particle size by pulverizing and classifying.

According to this production method (pulverization method), a considerably excellent toner can be produced, but there is a certain limitation, that is, a selection range of a toner material is limited. For example, the resin colorant dispersion must be sufficiently brittle and capable of being pulverized with economically available manufacturing equipment. Because of this requirement, the resin colorant dispersion must be made sufficiently brittle, and when this dispersion is actually finely pulverized at a high speed, particles having a wide particle size range are easily formed. A problem arises in that excessively finely divided particles are included in this group of particles. Further, such a highly brittle material is more susceptible to pulverization or pulverization when actually used for development in a copying machine or the like.

Further, in this pulverization method, it is difficult to uniformly disperse solid fine particles such as a magnetic powder or a colorant in a resin, and depending on the degree of dispersion of the solid fine particles, an increase in fog and a decrease in image density may occur. Great care must be taken in the extent of this dispersion, as it will cause it. Further, when the colorant is exposed on the fracture surface of the colored resin fine powder, the toner developing characteristics may fluctuate.

On the other hand, in order to overcome the problems of the toner by the pulverization method, a method of producing the toner by a suspension polymerization method has been proposed (JP-B-36-10231). In this suspension polymerization method, a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives)
After uniformly dissolving or dispersing into a monomer composition, the monomer composition is dispersed and granulated in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer using a suitable stirrer,
Simultaneously, a polymerization reaction is performed to obtain toner particles having a desired particle size.

This suspension polymerization method does not include a mechanical pulverization step, so that there is no inconvenience caused by pulverization as seen in the pulverization method.

As an apparatus used for dispersion and granulation, a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) can be mentioned. The apparatus is of a batch type, and has a characteristic of applying a high shearing force while convection of the liquid in the batch, has a low granulation efficiency, and requires a long time for granulation. In addition, since the treatment is performed for a long time, fine particles are easily generated.

As a device capable of continuous processing, there is TK homomic line flow (manufactured by Tokushu Kika Kogyo Co., Ltd.). However, this is also the same as above, that is, granulation efficiency is poor, so it is necessary to increase the number of passes. Therefore, granulation has a long time.

In addition, due to the complexity of cleaning for processing different kinds of materials (color change), etc., it is not sufficiently satisfactory when scale-up is considered.

[Means and Actions for Solving the Problems] In order to solve the above problems, the present inventors studied a granulation method having a novel high shear force function in the granulation process, and reached the present invention. It is.

The method of the present invention is a method for effectively producing a dry toner in the production of an electrostatic image developing toner by a suspension polymerization method. The toner having a small amount of a dispersion stabilizer and having a uniform and sharp particle size distribution. And a method for producing a toner with low cost and high productivity.

That is, the present invention provides a step of preparing a monomer mixture by dissolving and dispersing a mixture containing at least a polymerizable monomer, a colorant and a compound having a low softening point while heating the monomer mixture. A step of preparing a monomer composition by adding a polymerization initiator; a step of pre-dispersing the monomer composition in an aqueous medium; and a step of producing particles of the monomer composition in the aqueous medium. A method for producing a polymerized toner for electrostatic image development, comprising the steps of: forming polymerized toner particles from the particles of the obtained monomer composition, wherein in the granulating step, on the upstream side of the granulating step, A first comb-shaped concentric ring-shaped stator, and a first comb-shaped concentric ring-shaped rotor provided with a gap inside the first comb-shaped concentric ring-shaped stator. Rotating the first comb-shaped concentric ring-shaped rotor by using the first granulating means having From the first granulation step of generating particles of the monomer composition while applying a shearing force to the aqueous medium and the monomer composition conveyed from the inside toward the outside, and downstream of the granulation step, A second comb-shaped concentric ring-shaped stator having more teeth than the first comb-shaped concentric ring-shaped stator, and a gap provided inside the second comb-shaped concentric ring-shaped stator. A second comb-shaped concentric ring-shaped rotator having more teeth than the first comb-shaped concentric ring-shaped rotator installed by using the second granulating means; By rotating the comb-shaped concentric ring-shaped rotor, the particles of the monomer composition are further refined while applying a shearing force to the particles of the aqueous medium and the monomer composition conveyed from the inside to the outside. A method for producing a polymerized toner for electrostatic image development, comprising: a second granulation step.

Granulation means used in the granulation step in the production method of the present invention include a device such as Ebara Milder, a high-efficiency disperser manufactured by Ebara Corporation, and a DISHO, a high-efficiency disperser manufactured by Colma, West Germany. Is exemplified. The first example is the case of using Ebara Milder as a granulation means.
The present invention will be described in more detail with reference to the drawings.

First, a monomer composition containing a polymerizable monomer such as styrene, a colorant such as copper phthalocyanine blue, and a polymerization initiator is subjected to high shearing force in a liquid dispersion medium in which a dispersion stabilizer such as silica fine powder is present. Pre-dispersion is performed by a dispersing means such as a stirrer-type mixer to perform pre-granulation. The particles of the pre-granulated monomer composition maintain the particle state for a while even after the stirring by the stirring means is stopped due to the presence of the dispersion stabilizer on the particle surface.

The dispersion containing the predispersed monomer composition is pumped by a commonly used pump at 1 to 10 kg / min, preferably 3 to 10 kg / min.
At a discharge rate of 7 kg / min, it is supplied to the high-efficiency disperser Ebara Milder (manufactured by Ebara Corporation) used as a granulation means. In the granulating means, the dispersion liquid supplied to the inlet 1 is converted into a comb-shaped concentric ring-shaped rotor 4 having a comb-shaped shape and a comb-shaped concentric ring-shaped stator 3 having a comb-shaped shape with an inner / outer diameter. Due to the difference, shear flows when flowing from the inside to the outside of the interlocking part leaving a slight gap between each other. After repeating this process several times, the dispersion is sent to the outlet 2.

As a result, the monomer composition particles that have been coarse in the preliminary dispersion step are reduced into fine particles by receiving a sufficient shearing force. The combination of the rotor and the stator varies depending on the desired particle size, but in order to efficiently apply a shearing force, the order is usually coarse teeth with fewer teeth than the inlet side, intermediate teeth, and fine teeth with more teeth than the inlet side. .

In some cases, there are combinations of coarse teeth, fine teeth, and fine teeth.

When the monomer composition particles having a particle diameter of 1 to 10 μm are generated by the present apparatus, the viscosity of the monomer composition, the amount of the dispersion stabilizer, and the like vary. Is usually 2
It is preferred to repeat the granulation step up to 10 times.

The liquid temperature during the granulation process is such that the viscosity of the monomer composition is
s, preferably at a temperature of 10 to 5,000 cps, the particle size of the monomer composition particles can be made 1 to 10 μm, and finally the developing toner having a weight average particle size of 1 to 10 μm Can be manufactured. As the liquid dispersion medium, usually, water or an aqueous medium containing water as a main component is used, so that the liquid temperature of the dispersion during the granulation step is adjusted to 20 to 80 ° C, preferably 40 to 70 ° C. Is preferred.

In the dispersion, for 100 parts by weight of the monomer composition, the liquid dispersion medium is preferably present in an amount of 200 to 1000 parts by weight, and the dispersion stabilizer is 0.2 to 0.2 parts by weight based on the liquid dispersion medium.
It is preferred to use 5% by weight, preferably 0.4-2% by weight.

The preliminary dispersion of the monomer composition in the liquid dispersion medium is TK
This is done using a high shear mixer such as a homomixer. The preliminary dispersion may be performed for 1 to 60 minutes. At this stage, the monomer composition may already contain a polymerization initiator. Further, a suspension polymerization reaction may be performed by adding a polymerization initiator to a liquid medium containing monomer composition particles adjusted to a polymerization temperature after the granulation step.

Compared with the case where the monomer composition particles are produced using a high shear stirring and mixing apparatus that is frequently used in the conventional method, the present invention provides the same particle size having an average weight particle size of about 1 to 10 μ. Can be granulated with the use amount of the dispersion stabilizer of about 40 to 80%.

Further, maintenance such as cleaning of the apparatus is very easy.

The polymerizable monomer used in the present invention is a monomer having a CH ₂ ＣC <group, and includes the following monomers.
That is, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4
-Dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonyl Styrene and its derivatives such as styrene, pn-decylstyrene, pn-dodecylstyrene; ethylene, propylene, butylene,
Ethylene such as isobutylene and unsaturated monoolefins; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate , Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, Methacrylates such as diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n acrylate
Acrylates such as octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; maleic acid, maleic acid half ester; vinyl methyl ether, vinyl ethyl ether, vinyl Vinyl ethers such as isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-
N-vinyl compounds such as vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; Can.
Above all, it is preferable to use styrene or a styrene derivative alone or as a mixture with another monomer as a polymerizable monomer in terms of development characteristics and durability.

In order to improve the fixability and offset resistance in hot-press roller fixing, the monomer composition has low releasability such as waxes such as paraffin wax and low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene. It is preferred to add a point compound. In that case, the addition amount is 1 to 1 with respect to 100 parts by weight of the polymerizable monomer.
00 parts by weight.

Examples of the low softening point compound include paraffin, wax, low molecular weight polyolefin, modified wax having an aromatic group, hydrocarbon compound having an alicyclic group, natural wax, and a long hydrocarbon chain having 12 or more carbon atoms [CH ₃ CH _{2 11} or CH ₂
Long-chain carboxylic acids having ₁₂ or more aliphatic carbon chains], esters thereof, and the like. You may mix and use different low softening point compounds. Specifically, paraffin wax (made by Nippon Oil), paraffin wax (made by Nippon Seiwa),
Micro wax (made by Nippon Oil), microcrystalline wax (made by Nippon Seiwa), hard paraffin wax (made by Nippon Seiro), PE-130 (made by Hoechst), Mitsui High Wax 110P (made by Mitsui Petrochemical), Mitsui High Wax 220P
(Mitsui Petrochemical), Mitsui High Wax 660P (Mitsui Petrochemical), Mitsui High Wax 210P (Mitsui Petrochemical),
Mitsui High Wax 320P (Mitsui Petrochemical), Mitsui High Wax 410P (Mitsui Petrochemical), Mitsui High Wax 420P
(Mitsui Petrochemical), Heylets T-100X (Mitsui Petrochemical), Heylets T-200X (Mitsui Petrochemical), Heylets T-300X (Mitsui Petrochemical); Petrozine 80 (Mitsui Petrochemical), Petrozine 100 (Mitsui Petrochemical), Petrozine 120 (Mitsui Petrochemical), Tack Ace A-100 (Mitsui Petrochemical), Tack Ace F-100 (Mitsui Petrochemical), Tack Ace B-60 (Mitsui Petrochemical) ), Modified wax JC-1141 (Mitsui Petrochemical), modified wax JC-2130
(Mitsui Petrochemical), modified wax JC-4020 (Mitsui Petrochemical), modified wax JC-1142 (Mitsui Petrochemical),
Modified wax JC-5020 (manufactured by Mitsui Petrochemical); beeswax, carnauba wax, montan wax and the like.

The polymerizable composition may be subjected to suspension polymerization in the presence of the following crosslinking agent in order to form a crosslinked polymer. In particular, when no polymer, copolymer or cyclized rubber is added to the monomer composition, it is particularly preferable to add it.

Divinylbenzene, divinylnaphthalene, dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene Glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane, 2,2'-bis (4-acryloxydiethoxyphenyl) propane,
General crosslinking agents such as trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromoneopentyl glycol dimethacrylate, and diallyl phthalate can be used as appropriate.

If these cross-linking agents are used in a large amount, they are difficult to be dissolved by heat, resulting in inferior heat fixing property or hot pressure fixing property. If the amount used is small, the properties such as blocking resistance and durability required for the toner are deteriorated, and in the hot roll fixing, a part of the toner does not completely adhere to the paper but adheres to the roller surface, and the toner adheres to the next paper. It becomes difficult to prevent the offset phenomenon of transition. Therefore, the amount of these crosslinking agents used is 0.001 to 15% by weight based on the polymerizable monomer.
(More preferably 0.1 to 10% by weight).

The monomer composition contains a colorant, and as the colorant, conventionally known dyes, pigments, carbon black, and pigments such as grafted carbon black in which the surface of carbon black is coated with a resin. Can be used.
The coloring agent is contained in an amount of 0.1 to 30% based on the polymerizable monomer. If necessary, a charge control agent and a fluidity modifier may be added (internally added) to the toner. The charge control agent and the fluidity modifier may be used by mixing (externally adding) with the toner particles. Examples of the charge control agent include a metal complex of an organic compound having a carboxyl group or a nitrogen-containing group, a metal-containing dye, and nigrosine. Fluidity modifier or latent image carrier (photoreceptor)
Colloidal silica as a surface cleaning aid,
Fatty acid metal salts and the like. A fluidity improver such as Teflon fine powder or zinc stearate powder may be blended in order to prevent toner particles from agglomerating and improve fluidity.

To produce a magnetic polymerized toner, magnetic particles are added to the monomer composition. In this case, the magnetic particles also serve as a colorant. As the magnetic particles that can be used in the present invention, a substance that is magnetized when placed in a magnetic field is used, for example, iron, cobalt, powder of a ferromagnetic metal such as nickel or magnetite, maghemite, or an alloy or a compound such as ferrite. Powder. Magnetic fine particles having a particle size of 0.05 to 5 μm, preferably 0.1 to 1 μm are used.
In the case of producing a toner having a small particle diameter, it is preferable to use magnetic particles having a particle size of 0.8 μm or less. The content of the magnetic particles is 10 to 60 parts by weight, preferably 20 to 50 parts by weight, based on 100 parts by weight of the monomer composition. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or a suitable reactive resin. In this case, although it depends on the surface area of the magnetic fine particles and the density of the hydroxyl groups existing on the surface, 5% by weight or less (preferably 0.1 to
(3% by weight), sufficient dispersibility in the polymerizable monomer is obtained, and the physical properties of the toner are not adversely affected. Further, a mixture of lipophilic magnetic particles and hydrophilic magnetic particles may be used.

According to the findings of the present inventors, when a water-soluble polymerization initiator is used, the resulting polymerized toner has reduced moisture resistance,
Since the development characteristics and blocking resistance at high temperature and high humidity are deteriorated, it is preferable to use a substantially water-insoluble polymerization initiator in order to produce a polymerized toner having excellent environmental characteristics.

As described above, the polymerization initiator used in the present invention is preferably substantially insoluble in water. The substantially water-insoluble polymerization initiator in the present invention refers to 100 g of water at room temperature.
It has a solubility of 1 g or less, preferably 100 g of water
0.5 g or less, particularly preferably 0.2 g for 100 g of water
It has the following low solubility. 1g for 100g of water
In the case where the polymer has the above-mentioned solubility, the decomposition product of the polymerization initiator remaining on the surface of the polymerized toner particles after the polymerization is completed is not preferable because the moisture resistance of the polymerized toner is reduced. Also,
The polymerization initiator used in the present invention is soluble in the polymerizable monomer, and is preferably a polymerizable monomer in the amount usually used (1 to 10 polymerization parts of polymerization initiator per 100 parts by weight of monomer). It has a solubility property of dissolving in the monomer. As a polymerization initiator, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2 , 2'-azobis-
Azo or diazo polymerization initiators such as 4-methoxy-2,4-dimethylvaleronitrile and other azobisisobutyronitrile (AIBN); benzoyl peroxide,
Examples include peroxide polymerization initiators such as methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorylbenzoyl peroxide, and lauroyl peroxide. In the production method of the present invention, the polymerization initiator preferably has a melting point equal to or lower than the polymerization temperature (normally 50 ° C. or higher). It is also preferable to use a mixture of two or more polymerization initiators for the purpose of adjusting the molecular weight and molecular weight distribution of the polymer or for adjusting the reaction time.

The amount of the polymerization initiator to be used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerization monomer. If the amount is less than 0.1 part by weight, it is difficult to uniformly disperse or impart a sufficient amount of the polymerization initiator to each monomer composition particle,
If the amount is more than 100 parts by weight, the molecular weight of the polymerization product is too low because the amount is too large, and the tendency for the polymerization reaction to occur unevenly increases.

The suspension polymerization reaction is usually carried out at a polymerization temperature of 50 ° C. or higher (for example, 55 to
70 ° C.), and the upper limit temperature is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator is undesirably rapidly decomposed.

Further, when a polar polymer having a polar group soluble in the polymerizable monomer used as an additive in the monomer composition, a polar copolymer or a cyclized rubber is added to polymerize the polymerizable monomer. A preferred polymerized toner can be obtained. Polar polymers, polar copolymers or cyclized rubbers are polymerizable monomers 100
It is preferable to add 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight based on parts by weight. If the amount is less than 0.5% by weight, it is difficult to obtain a sufficient pseudo-capsule structure. If the amount is more than 50 parts by weight, the amount of the polymerizable monomer becomes insufficient, and the characteristics as a polymerized toner tend to deteriorate. A polymerizable monomer composition to which a polar polymer, a polar copolymer, or a cyclized rubber is added is suspended in an aqueous phase of an aqueous medium in which the polar polymer and an inversely charged fine powder dispersion stabilizer are dispersed. And polymerization. That is, the cationic or anionic polymer, the cationic or anionic copolymer or the anionic cyclized rubber contained in the polymerizable monomer composition contains an oppositely charged anion dispersed in an aqueous medium. Electrostatic or cationic fine powder dispersion stabilizer electrostatically attracts to the surface of the toner particles, and the fine particle dispersion stabilizer covers the particle surface to prevent coalescence of the particles, stabilize them, and add the added polarity. Since the polymer, the polar copolymer or the cyclized rubber is collected on the surface layer of the particles serving as the toner, the particles form a kind of shell, and the obtained particles have a pseudo capsule structure. The relatively high molecular weight polar polymer, polar copolymer or cyclized rubber collected on the surface layer of the particles imparts excellent properties such as blocking properties, developability, charge control properties, and abrasion resistance. Some examples of the polar polymer (including the polar copolymer and the cyclized rubber) and a part of the dispersant having a charge property that can be used in the present invention are shown below. The polar polymer is GPC
Those having a weight average molecular weight of 5,000 to 500,000 measured in the above are preferably used because they dissolve well in the polymerizable monomer and have durability.

(I) Examples of the cationic polymer include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl acrylate, a copolymer of styrene and the nitrogen-containing monomer, styrene, and an unsaturated carboxylic acid ester. And the nitrogen-containing monomer.

(Ii) Examples of the anionic polymer include nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid, unsaturated dibasic acids, and unsaturated dibasic acids. There is an anhydride polymer or a copolymer of styrene and the monomer. Also, a cyclized rubber can be used as the anionic polymer.

As the dispersion stabilizer, an inorganic fine powder which has the ability to stabilize the dispersion of the monomer composition particles in a liquid medium such as an aqueous medium and is hardly soluble in water is preferred. The amount of the dispersant added to the aqueous medium is preferably 0.2 to 5% by weight (preferably 0.4 to 2% by weight) based on water, as described above.

(Iii) Aerosil # 200,
Colloidal silica such as # 300 (manufactured by Nippon Aerosil Co., Ltd.), Nipsil E-220A (manufactured by Nippon Silica), and Fine Seal T-32 (manufactured by Tokuyama Soda) are available.

(Iv) Examples of the cationic dispersant include aluminum oxide, magnesium hydroxide, and hydrophilic positively chargeable silica fine powder such as aminoalkyl-modified colloidal silica treated with a coupling agent.

In the production method of the present invention, a dispersion stabilizer is required, but it is not always necessary to use a polar polymer and a fine powder dispersion stabilizer having reverse charge in a liquid medium.

Also, suitable stabilizers such as polyvinyl alcohol, gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginate, zein, casein, triphosphate Any one or a mixture of calcium, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide, thorium hydroxide, etc. in an aqueous medium to such an extent that the production method of the present invention is not adversely affected. Those contained may also be used.

Further, for uniform dispersion of the inorganic dispersion stabilizer, a surfactant may be used to such an extent that the production method of the present invention is not adversely affected. This is to promote the intended action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, and allyl-alkyl-poly. Sodium ether sulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate,
Calcium oleate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6
Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-
Sodium triphenylmethane-4,4-diazo-bis-β-naphthol-disulfonate and the like can be mentioned. However, it should be noted that when a hydrophilic organic stabilizer or surfactant is used, the moisture resistance of the polymerized toner is reduced.

It is also preferred to add a Bronsted acid, such as hydrochloric acid, to the aqueous medium to increase the ionization of the polar groups of the polar polymer or cyclized rubber in the monomer composition. In particular, adding a Bronsted acid, such as hydrochloric acid, in an aqueous medium involves:
It is effective in further enhancing the effect of the anionic polymer, anionic copolymer or cyclized rubber.

After completion of the reaction, post-treatment is carried out by a usual method to obtain polymerized toner particles. For example, a polymerized toner is obtained by washing the produced polymer particles, removing the dispersion stabilizer, and then collecting and drying the resulting particles by an appropriate method such as filtration, decantation, or centrifugation.

The polymerized toner obtained by the production method of the present invention can be applied to a known dry electrostatic image developing method. For example, two-component developing methods such as a cascade method, a magnetic brush method, a microtoning method, and a two-component AC bias developing method; magnetic toners such as a conductive one-component developing method, an insulating one-component developing method, and a jumping developing method are used. One-component developing method; powder cloud method and fur brush method; non-magnetic one-component developing method in which the toner is conveyed to the developing unit by being held on a toner carrier by electrostatic force and developed; The present invention is applicable to an electric field curtain developing method in which the film is transported and developed.

[Examples] Hereinafter, the present invention will be described in detail based on examples. still,
All parts in the following formulations are parts by weight.

Example 1 7.5 parts of γ-aminopropyltrimethoxysilane was added to 24,000 parts of ion-exchanged water, and 150 parts of Aerosil # 200 (manufactured by Nippon Aerosil) were added. (Industrial product) at 3,000 rpm for 15 minutes. Further, 1 / 10N-hydrochloric acid was added, and p of the aqueous medium was
H was adjusted to 6.

The components of the above formulation were heated to 70 ° C. in a container and dissolved and dispersed at 3,000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a monomer mixture. While maintaining the temperature at 70 ° C., 200 parts of an initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved to prepare a monomer composition.

In the dispersion medium, put the monomer composition, 70 ° C.
Disperse at 3,000 rpm with a TK homomixer, and adjust the rotation speed to 5,000 rpm so that the outermost peripheral speed is 15 m / sec. Ebara Milder (manufactured by EBARA CORPORATION) with a pump output of 3 kg / min, and a granulation step of generating particles of the monomer composition was performed. In the used Ebara Milder, the coarse teeth formed by a comb-shaped concentric ring-shaped stator having 10 teeth and a comb-shaped concentric ring-shaped rotor having 10 teeth further inside are 1 tooth. Behind the coarse teeth, a first comb-shaped concentric ring stator having 20 teeth and a first concentric ring-shaped stator having 20 teeth further inside are provided behind the coarse teeth. A second comb tooth type concentric ring-shaped stator having 20 teeth inside the rotor and a second comb tooth type concentric ring-shaped rotor having 20 teeth inside and a number of teeth further inside And two intermediate teeth formed by a third concentric ring-shaped stator having 20 teeth and a third concentric ring-shaped rotor having 20 teeth on the inner side. ing. After performing this granulation step three times, the mixture was stirred at 70 ° C. for 10 hours with a paddle stirring blade to complete the polymerization.

Thereafter, the mixture was cooled and sodium hydroxide was added thereto to dissolve Aerosil # 200 as a dispersion stabilizer, followed by drying and drying to obtain a polymerized toner. When the particle size of the obtained toner was measured by a Coulter counter (aperture diameter: 100 μm), the volume average particle size was 9.4 μm and had a sharp particle size distribution. The triboelectric charge (tribo value) of this toner by iron on iron powder (200/300 mesh) by a blow-off method was -19.5 μC / g. Further, when visually observed using an optical microscope, the dispersibility of the colorant (copper phthalocyanine blue) was good, and almost no transparent particles were recognized.

Example 2 The rearmost intermediate tooth of the Ebara Milder used in Example 1 was replaced with a first comb tooth type concentric ring stator having 28 teeth and a first intermediate tooth having 28 teeth. Comb-shaped concentric ring-shaped rotor, a second comb-shaped concentric ring-shaped stator having 28 teeth on the inner side, and a second comb-shaped concentric ring-shaped rotor having 28 teeth on the inner side And a third comb-shaped concentric ring-shaped stator having 28 teeth further inside and a third comb-shaped concentric ring-shaped rotor having 28 teeth further inside. Except for changing the teeth, the same operation as in Example 1 was performed to obtain a polymerized toner. When the particle size of the obtained toner was measured by a Coulter counter (aperture diameter: 100 μm), the volume average particle size was 7.4 μm and had a sharp particle size distribution. The amount of triboelectricity (tribo value) of this toner with respect to iron powder (200/300 mesh) by a blow-off method is −23.2 μC /
g. Further, when visually observed using an optical microscope, the dispersibility of the colorant (copper phthalocyanine blue) was good, and almost no transparent particles were recognized.

Example 3 The above formulation was dispersed in an ultrasonic disperser heated to 70 ° C. (RUS-300, manufactured by Nippon Seiki Seisakusho, frequency 20 KHz, output 30 W) for 15 minutes to perform a hydrophobic treatment of carbon black.

next, Was added, and the mixture was heated to 70 ° C., dissolved or dispersed to prepare a monomer composition.

Separately, the above monomer composition was put into a 40 l stainless steel container containing an aqueous dispersion medium in which 200 parts of Aerosil # 200 (manufactured by Nippon Aerosil) was dispersed in 24,000 parts of water. A polymerized toner was obtained.

The particle size of the obtained toner was measured by a Coulter counter (aperture diameter: 100 μm).
It had a sharp particle size distribution at 0.5 μm. The triboelectric charge (tribo value) of this toner by iron on iron powder (200/300 mesh) by a blow-off method was +12.3 μC / g.
In addition, when visually observed using an optical microscope, the dispersibility of carbon black was good, and almost no transparent particles were present.

Comparative Example 1 0.5 parts of γ-aminopropyltrimethoxysilane was added to 1,200 parts of ion-exchanged water, and 10 parts of Aerosil # 200 (manufactured by Nippon Aerosil) was further added. And dispersed at 3,000 rpm for 15 minutes. Further, 1 / 10N-hydrochloric acid was added to adjust the pH of the aqueous dispersion medium to 6.
Was adjusted.

The components of the above formulation were heated to 70 ° C. in a container, and dissolved and dispersed at 3,000 rpm for 5 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to obtain a monomer mixture. Further, 10 parts of initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved while maintaining the temperature at 70 ° C. to prepare a monomer composition.

In the dispersion medium obtained above, put the monomer composition,
8, using a TK homomixer (manufactured by Tokushu Kika Kogyo) at 70 ° C
The mixture was stirred at 000 rpm (peripheral speed 15 m / sec) for 1 hour to granulate the monomer composition. Thereafter, in the same manner as in Example 1, the mixture was stirred at 70 ° C. for 10 hours with a paddle stirring blade to complete the polymerization. Thereafter, the mixture was cooled and sodium hydroxide was added thereto to dissolve Aerosil # 200 as a dispersion stabilizer, followed by filtration and drying to obtain a polymerized toner.

The particle size of the obtained toner was measured with a Coulter counter (aperture diameter: 100 μm).
It was 1.5 μm. The triboelectric charge (tribo value) of the toner by iron on iron powder (200/300 mesh) by the blow-off method was -18. 1 μC / g.

[Effects of the Invention] As described above, the method of the present invention can provide a toner with low cost, good productivity, and a sharp particle size distribution.

[Brief description of the drawings]

FIG. 1 is a drawing showing an example of an apparatus used in the granulation step of the method of the present invention.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-203167 (JP, A) JP-A-62-299863 (JP, A) JP-A-61-83202 (JP, A) 289802 (JP, A) "Chemical equipment December 1983" "Ebara Tokyou 133"

Claims (1)

(57) [Claims] 1. A step of preparing a monomer mixture by dissolving and dispersing a mixture containing at least a polymerizable monomer, a colorant and a compound having a low softening point while heating, and polymerizing the monomer mixture. A step of preparing a monomer composition by adding an initiator, a step of pre-dispersing the monomer composition in an aqueous medium, and a step of forming particles of the monomer composition in the aqueous medium And a method for producing a polymerized toner for electrostatic image development, comprising the step of generating polymerized toner particles from the particles of the obtained monomer composition, wherein in the granulation step, the upstream side of the granulation step, A first comb-shaped concentric ring-shaped stator, and a first comb-shaped concentric ring-shaped rotor provided with a gap inside the first comb-shaped concentric ring-shaped stator. By using the first granulating means and rotating the first comb-shaped concentric ring-shaped rotor, A first granulation step of generating particles of the monomer composition while applying a shearing force to the aqueous medium and the monomer composition conveyed from the inside to the outside, and downstream of the granulation step, A second comb-shaped concentric ring-shaped stator having more teeth than the first comb-shaped concentric ring-shaped stator, and a gap provided inside the second comb-shaped concentric ring-shaped stator. A second comb-shaped concentric ring-shaped rotor having a larger number of teeth than the first comb-shaped concentric ring-shaped rotor installed is used; By rotating the comb-shaped concentric ring-shaped rotor, the particles of the monomer composition are further refined while applying a shearing force to the particles of the aqueous medium and the monomer composition conveyed from the inside to the outside. 2. A method for producing a polymerized toner for electrostatic image development, comprising: