JPH07120078B2 - Method for producing toner for developing electrostatic image - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a toner for developing an electrostatic charge image, and more particularly to a spherical toner having a monodispersed particle size distribution without generating fine defective particles. The present invention relates to a method for producing a toner for developing an electrostatic image with high productivity.

[Prior Art and its Problems] Conventionally, electrophotographic toners used in electrophotography, electrostatic printing, etc. are obtained by melt-kneading a thermoplastic resin, a colorant, and other additives such as a charge control agent. It has been manufactured by a process of cooling and pulverizing the mixture, classifying the pulverized product, and adjusting it to a certain particle size range. However, the yield of the toner obtained by this pulverization / classification is extremely low, and a large amount of equipment is required for these operations, which makes the manufacturing cost of the toner extremely high. Further, although the toner obtained by pulverization can obtain a certain level of performance, it has been recognized that the toner has poor flowability due to the irregular shape of the toner and that blocking easily occurs in the developing device.
Further, the irregular toner has different triboelectrification properties because the charge of each toner particle is different, and the poor fluidity makes it impossible to keep the developing property constant as the developing operation proceeds. The problem of causing image deterioration is also recognized.

Further, in recent years, image forming apparatuses such as copying machines using electrophotography have been required to have high reliability such as maintenance-free, multicolor image formation and high quality image formation. For example, in color (chromatic) image formation, especially in color (chromatic) images such as OHP, the hue of the toner-fixed image is required for the transmitted image, and the surface of the fixed image is difficult to diffusely reflect transmitted light. It is necessary to form the toner more smoothly, and spherical toner is required so that the toner easily forms a uniform layer and each toner easily melts uniformly. The characteristics of the toner are not deteriorated by repeated copying operations, and even if toner is newly supplied according to the consumption of toner, the developer characteristics in the developing device do not always change. A toner having a uniform particle size has been demanded.

As a method for solving the above-mentioned problems of the pulverized toner and the manufacturing thereof and for manufacturing spherical toner all at once during the polymerization process of the fixing resin, a method of manufacturing a toner by a suspension polymerization method has been proposed. However, although it is possible to produce spherical particles having a practical toner size by the method of producing a toner by suspension polymerization, the particle size distribution of the obtained particles is very polydisperse and contains a lot of ultrafine particles and coarse particles. Then, as a method of obtaining toner particles having a uniform particle size in the suspension polymerization method, for example, it has been attempted to suspend a polymerizable composition containing a toner property imparting agent in a dispersion medium at high temperature, In order to obtain oil droplet particles having a uniform particle diameter, it is necessary to make the polymerizable composition have a low viscosity, and substantially raise the temperature to a temperature above the temperature at which the polymerization initiator decomposes to make the polymerizable composition have a low viscosity. There is a need to. Therefore, the polymerization initiator decomposes during granulation and radicals are rapidly generated, the polymerization reaction does not proceed well, and the polymerization reaction itself is inhibited, so that a sufficiently satisfactory effect is not obtained. Further, in order to obtain a toner having a narrow particle size distribution, the toner obtained by suspension polymerization can be classified and used. However, in the pulverization method, the defective toner that has been classified and removed can be reused by circulating it again to the melt-kneading step.
It is difficult to mix ultrafine particles and coarse particles generated by suspension polymerization with a polymerizable composition for reuse, resulting in extremely low productivity.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional art, and an object of the present invention is to easily form a spherical toner having an appropriate particle diameter without generating fine particles and coarse particles. Moreover, it is to provide a method of manufacturing with high productivity.

Another object of the present invention is to provide a manufacturing method for obtaining toner particles having a spherical shape and having small differences in characteristics such as fluidity and triboelectric charging characteristics.

[Means for solving problems]

A water-miscible organic solvent that dissolves a monomer but does not dissolve the polymer or a mixed solution of the water-miscible organic solvent and water is used as a solvent, and the monomer, the nuclear material or the monomer is used. A swelling seed polymer particle, a dispersion stabilizer, a toner property-imparting agent such as a colorant, and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, and this dispersion is brought into contact with water through a semipermeable membrane. To form an oil droplet composed of a monomer centering on a nuclear substance, a colorant and a polymerization initiator, or to absorb the monomer, the colorant and the polymerization initiator in the seed polymer, The object of the present invention is achieved by producing toner particles by selectively polymerizing the monomers in the droplets or the seed polymer.

[Action]

In the present invention, a water-miscible organic solvent which dissolves a monomer but does not dissolve the polymer or a mixed solution of the organic solvent and water is used as a solvent / nuclear substance or seed weight for dissolving the monomer. It is used as a dispersion medium for dispersing coalesced particles, in which a monomer, a nuclear material or a seed polymer, a dispersion stabilizer, a toner property imparting agent such as a colorant, and an oil-soluble polymerization initiator are dissolved or Disperse.

That is, in the solvent / dispersion medium used in the present invention, the solubility of the monomer, the toner property imparting agent, and the polymerization initiator is remarkably decreased by the addition of water. Therefore, the monomer which cannot be dissolved in the dispersion medium, the toner property-imparting agent, the oil-soluble substance such as the polymerization initiator, when seed polymer particles exhibiting swelling property with respect to the monomer are present in the system, It is absorbed by the seed polymer and swelling of the polymer particles occurs. On the other hand, when there is no substance capable of stably presenting the oil-soluble substance as described above, the monomer which cannot be dissolved in the dispersion medium, the toner property imparting agent, the polymerization initiator and the like are stable. In order to obtain a stable state, they gather around the nuclear material and the like together with a dispersion stabilizer to form oil droplets. In this case, even if it is not a nuclear substance, even if dust or dust is present, it may trigger the oil-soluble substance to collect. Therefore, in addition to the nuclear substance, it is necessary to remove substances that are likely to become nuclei of oil droplets in advance.

A dispersion stabilizer must be added to the polymerization system in order to form oil droplets or to allow the seed polymer particles to exist as stable and independent dispersed particles in the dispersion medium as described above.

Thus, in the dispersion medium, spherical particles having almost the same size are formed by the number of the nuclear material or the seed polymer, and the monomers in the particles are selectively polymerized to obtain a monodisperse particle. Toner particles are formed.

It is important that the initiation of polymerization is selectively carried out only for the monomer absorbed in the oil droplets or in the seed polymer, and if the polymerization is initiated for the monomer dissolved in the dispersion medium, this formation The monomer is absorbed into the polymer particles, and particle growth occurs, and it becomes difficult to obtain monodisperse polymer particles.Therefore, the polymerization initiator is oil-soluble, and oil droplets or seeds together with the monomer are obtained. It is desirable to be absorbed in the polymer. It is also necessary that the toner property imparting agent such as a colorant is uniformly absorbed in each oil droplet or the seed polymer, and it is oil-soluble like the polymerization initiator and in the oil droplet or the seed polymer together with the monomer. It is desirable to be absorbed by.

As described above, the method of the present invention uses the decrease in the solubility of the monomer, the toner property-imparting agent, and the polymerization initiator in the solvent / dispersion medium as a driving force to force the swelling of the seed polymer particles by the monomer and the like. In particular, it is characterized in that it is brought into contact with water through a semipermeable membrane as a means for reducing the solubility of monomers and the like. That is, water can be introduced into the dispersion system through the semipermeable membrane in a relatively uniform state due to the difference in osmotic pressure, and the organic solvent in the dispersion system can also be discharged out of the system. In particular, discharging the organic solvent out of the system is effective in significantly reducing the number of monomers dissolved in the solvent, and is effective in preventing the monomers from polymerizing alone to form particles having a small particle size. There is.

From the above action, the semipermeable membrane passes only water and an organic solvent,
On the other hand, it is desirable that the monomer, the core material, the seed polymer, the toner property-imparting agent and the polymerization initiator do not pass through. However, a material such as cellophane which allows a monomer or a polymerization initiator to pass therethrough can be sufficiently used. this is,
Since the rate of water penetration into the system is faster than the diffusion of polymerization initiators and monomers, the solubility of the monomers and polymerization initiators decreases with it, and the formation of oil droplets around the nuclear material. It is considered that this is because absorption into the seed polymer occurs rapidly. On the other hand, if a semipermeable membrane that allows monomers and polymerization initiators to pass through, such as cellophane, is used, the monomers remaining in the dispersion medium will polymerize to form small particles after forming proper particles. In order to prevent this, it is possible to remove excess dispersion stabilizer or monomer through the semipermeable membrane and polymerize leaving only oil droplets or seed polymer particles that do not pass through the semipermeable membrane in the system. It is also possible to apply pressure to the water side so that the monomers and the polymerization initiator do not diffuse through the membrane so that the water is forced into the dispersion system. Further, the solubility decreasing effect can be promoted by combining two or more kinds of means for lowering the temperature of the dispersion system and means for adding an electrolyte such as sodium chloride into the system.

As described above, according to the method of the present invention, the monomer, the toner property imparting agent, and the polymerization initiator are used to reduce the solubility of the monomer, the toner property imparting agent, and the polymerization initiator in the specific solvent / dispersion medium. By forming oil droplets around the substance or absorbing it in the seed polymer, particles of a desired size can be efficiently formed within a short time, and selective polymerization of the monomer in the particles becomes possible. Therefore, it is possible to obtain a spherical electrostatic charge development-like toner which has a fixing property and a voltage detecting property, and has a particle size of a practical toner size and a monodispersed particle size distribution.

[Preferred embodiment]

Monomer The monomer used in the present invention is an ethylenically unsaturated monomer having radical polymerizability, and suitable examples thereof include monovinyl aromatic monomer, acrylic monomer and vinyl ester monomer. Polymers, vinyl ether-based monomers, diolefin-based monomers, mono-olefin-based monomers, halogenated olefin-based monomers, polyvinyl-based monomers and the like.

The monovinyl aromatic monomer has the formula (In the formula, R ₁ is a hydrogen atom, a lower alkyl group or a halogen atom, and R ₂ is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group, a vinyl group or a carboxyl group.) Monovinyl aromatic hydrocarbons such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene,
O-, m-, p-chlorostyrene, p-ethylstyrene, sodium styrenesulfonate, and divinylbenzene may be used alone or in combination of two or more, and the above-mentioned other monomers are as follows. Are listed respectively.

formula (In the formula, R ₃ is a hydrogen atom or a lower alkyl group, R ₄ is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms, a hydroxyalkyl group,
Vinyl ester group or aminoalkyl group) acrylic monomer such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, acrylic acid Phenyl, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, butyl γ-hydroxylate, butyl δ-hydroxyl acrylate, ethyl β-hydroxymethacrylate, γ-aminopropyl acrylate , Γ-N, N-diethylamino propyl acrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and the like.

formula (Wherein R ₅ is a hydrogen atom or a lower alkyl group), for example vinyl formate, vinyl acetate, vinyl propionate and the like.

formula (In the formula, R ₆ is a monovalent hydrocarbon group having up to 12 carbon atoms), for example, vinyl methyl ether, vinyl ethyl ether, vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like.

formula (Wherein each of R ₇ , R ₈ and R ₉ is a hydrogen atom, a lower alkyl group or a halogen atom), particularly butadiene, isoprene, chloroprene and the like.

formula (Wherein each of R ₁₀ and R ₁₁ is a hydrogen atom or a lower alkyl group), especially ethylene, propylene, isoprene, butene-1, pentene-1, 4-methylpentene-1 and the like.

Examples of halogenated olefin monomers include vinyl chloride and vinylidene chloride, and examples of polyvinyl monomers include divinylbenzene, diallyl phthalate,
Examples include triallyl cyanurate and the like.

These monomers may be used alone or in combination of two or more. Suitable monomers are styrene, (meth) acrylic acid esters, styrene / (meth) acrylic acid esters, styrene / divinylbenzene.

Organic solvents Water-miscible organic solvents include methanol, ethanol,
Lower alcohols such as isopropanol; polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol, triethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; Esters such as ethyl acetate; organic acids such as formic acid, acetic acid, propionic acid and the like. Among these, a monomer that dissolves but a polymer that does not dissolve can be used in combination with the monomer. used. An organic solvent which is excellent in the solubility of the monomer and which can be mixed with water at an arbitrary ratio and therefore is particularly useful for the purpose of the present invention is a lower alcohol such as ethanol.

This water-miscible organic solvent can be used alone,
It can also be used in the form of a mixed solution with water. In this latter case, it is desirable to contain water as much as possible within a range that does not practically reduce the solubility of the monomer, and the mixing ratio is determined by the monomer and the organic solvent used. When a lower alcohol is used as the solvent, the organic solvent and water can be used in a volume ratio of 10: 1 to 3: 5, particularly 4: 3 to 3: 4.

Nuclear Material The nuclear material used in the present invention acts as the core of the polymer.

The nuclear material may be a conventionally known monodisperse spherical colloid, and examples thereof include gold sol, chromium, zirconium, titanium, alumina, and copper.
Examples thereof include metal hydroxide sols of thorium and iron, silica, silver, carbon black inorganic pigments, magnetic powders and the like.

Of these, when magnetic powder is used as a nuclear substance, a magnetic toner used in a magnetic one-component developing method or the like is produced. The magnetic powder may be any substance that is magnetized by being placed in a magnetic field, and for example, a ferromagnetic metal such as iron, cobalt, nickel, or an alloy or compound such as magnetite, hematite, or ferrite is used.

Further, when carbon black or an inorganic pigment is used as the core substance, the toner can be manufactured without adding a colorant. As the inorganic pigment, a commonly used known pigment can be used.

The above-mentioned nuclear material has a monodisperse particle size distribution, and its particle size is preferably in the range of generally 0.01 to 20 μm, particularly 0.5 to 10 μm.

Seed Polymer Particles The seed polymer particles used in the present invention are swellable with respect to the above-mentioned monomers, and are polymer particles obtained by polymerizing one or more of the above-mentioned monomers. Is. The polymer particles are generally formed from the same kind of monomer as the monomer used, but may be formed by polymerization of a monomer different from this monomer. The former example is a combination of styrene polymer particles and a styrene monomer, and the latter example is a combination of acrylic polymer particles and a styrene monomer.

The seed polymer particles have a monodisperse particle size distribution,
The particle size is generally 0.01 to 50 μm, especially 0.5 to 20 μm
It is desirable to be within the range. Such seed polymer particles can be easily obtained by a known dispersion polymerization method, emulsion polymerization method, or by pulverizing and classifying the polymer.

Dispersion stabilizer As a dispersion stabilizer for improving the dispersibility of the seed polymer particles in the solvent and dispersion medium, known per se, polyvinyl alcohol, methyl cellulose, ethyl cellulose,
Polymer dispersion stabilizers such as polyacrylic acid, polyacrylic imide, polyethylene oxide, poly (hydroxystearic acid-g-methyl methacrylate-co-methacrylic acid) copolymer, nonionic surfactants, anionic interfaces Activators, cationic surfactants, amphoteric surfactants and the like are used.

Among these, polymer dispersion stabilizers such as polyvinyl alcohol are suitable, and give good results when combined with an organic solvent-water mixture.

Polymerization Initiator Any polymerization initiator can be used as long as it is oil-soluble. For example, as a radical polymerization initiator,
Suitable for azo compounds such as azobisisobutyronitrile and monomers such as cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide and lauroyl peroxide. A melt is used. Further, in the case of polymerization by ultraviolet rays, an oil-soluble photopolymerization initiator known per se can be used. Among the oil-soluble ones, it is particularly preferable to use a polymerization initiator which is hardly dissolved in the organic solvent so that the monomer is difficult to polymerize alone in the organic solvent.

Colorant and Other Toner Characterizing Agent As the colorant, an oil-soluble one of the commonly used known colorants, for example, CI Solvent Yellow 2, C.
I. Solvent Yellow 14, CI Solvent Yellow 60, CI Solvent Orange 7, CI Solvent Red 3, CI Solvent Red 24, CI Solvent Red 27, CI Solvent Violet
13, CI Solvent Blue 7, CI Solvent
Blue 35, CI Solvent Green 15, CI Solvent Brown 5, etc. are used. In the method of forming the oil droplets by assembling the toner composition with the nuclear material,
When adding an inorganic pigment, it becomes the core itself,
Except when the pigment itself is used as the core material, it is difficult to deposit the inorganic pigment as a colorant around other core materials. However, in the method of absorbing in the seed polymer, the inorganic pigment is surface-modified by grafting with a polymer chain, surface treatment with various coupling agents and long-chain alkylamines such as dodecylamine, and the like. It can be used by improving the affinity with the monomer. These colorants are used in an amount of 1 to 30 parts by weight, preferably 5 to 20 parts by weight, per 100 parts by weight of the monomer.

Further, for the purpose of adjusting the charging characteristics of the toner, an oil-soluble charge control agent conventionally used, for example,
Nigrosine dye (CINo.50415B), oil black (CINo.26150), spirone black, etc. can be used.
Similar to the above-mentioned colorant, the charge control agent also includes naphthenic acid, salicylic acid, octylic acid, fatty acids, manganese of resin acids, iron, cobalt, lead, zinc, cerium, calcium, nickel, etc. when a seed polymer is used. In some cases, the metal salts such as metal soaps, metal-containing azo dyes, pyrimidine compounds, metal chelates of alkylsalicylic acid and the like can be preferably used to the extent that the polymerization reaction is not inhibited. Generally 10
It is preferable to use 1 to 40 parts by weight, particularly 2 to 15 parts by weight, per 0 parts by weight.

Semipermeable membrane As a semipermeable membrane, cellophane, collodion membrane, sulfuric acid paper, cellulose membrane, cellulose derivative membrane, acrylonitrile-
Dialysis membranes such as sodium methacryl sulfonate copolymer membranes, polycarbonate-polyether block copolymer membranes, ethylene-vinyl alcohol copolymer membranes; cellulose acetate membranes such as cellulose acetate and cellulose acetate sulfate, polyamide hydrazides, polypiperazine Polyamide-based membranes such as amides and m-phenylisophthalamide-terephthalamide copolymers, polyethyleneimine-based membranes, polyethyleneoxide-based membranes, pylon, polybenzimidazolone,
Reverse osmosis membranes such as polyimide; ultrafiltration membranes such as cellulose dioxide, polybenzoxazinedione sulfonated, polyamide-imide, etc. that are relatively small in permeation can be used.

Polymerization Method According to the present invention, first, a monomer is dissolved in a water-miscible organic solvent or a mixed solution of this and water. The amount of the monomer dissolved varies considerably depending on the solvent and the kind and composition of the monomer, but is generally 0.01 to 50% by weight, particularly 1 to 29% by weight.
Is preferred.

To this solution, a nuclear material or seed polymer particles, a toner property imparting agent, a dispersion stabilizer, and a polymerization initiator are added. The addition amounts of the nuclear material and the seed polymer particles differ depending on the desired degree of particle size. That is, most of the monomers present in the system are distributed in the number corresponding to the number of the nuclear substances or seed polymers, so that the monomers necessary for forming a toner having a desired particle diameter are the nuclear substances or the seed polymers. It is necessary to determine the addition amounts of the nuclear material and the seed polymer so that they are distributed per united product. Generally, the nuclear material or seed polymer particles and the monomer in the system are 1: 1 to 1: 1.
0 ⁹ particular to desirably is present in a weight ratio of 1:10 to 1:10 ^6, whereas the concentration of the seed polymer particles in the dispersion is generally 0.01 to 50% by weight, in particular from 0.1 to 20 wt% Good to use. Further, the dispersion stabilizer is preferably used in an amount of 0.1 to 30% by weight, particularly 1 to 10% by weight, based on the seed polymer particles, while the polymerization initiator is 0.001 per charged monomer.
It is preferably used in an amount of 10 to 10% by weight, particularly 0.01 to 0.5% by weight.

By bringing this dispersion system into contact with water through a semipermeable membrane, an oil droplet centering on a nuclear substance is formed by a charged monomer, a toner property imparting agent, a polymerization initiator, or the like, or in a seed polymer particle. It can be deposited and absorbed. Generally, it is desirable to absorb 50% by weight or more, especially 90% by weight or more of the charged monomers into oil droplets or seed polymer particles. It is a remarkable feature of the present invention that this process is performed within an extremely short time.

As a method of contacting the dispersion with water, a means of putting water filled in the dispersion into the dispersion, a means of partitioning with a semipermeable membrane in water, a partition with a semipermeable membrane There is a means such as putting the dispersion system and water into the container at the same time, but increase the contact area per volume of the dispersion system so that the water diffuses as uniformly as possible in the dispersion system, and the dispersion system flows. Therefore, it is desirable to provide a stirring means. Moreover, for example, if a tubular device is partitioned by a semipermeable membrane and water and a dispersion system are contacted by convection, efficient continuous production can be achieved.

The oil droplets or the monomers absorbed in the polymer particles are then polymerized. Polymerization is generally carried out in an inert atmosphere such as nitrogen-
It is carried out at a temperature of 30 ° C to 90 ° C, especially 30 ° C to 80 ° C. The polymerization conditions differ depending on the type of the polymerization initiator, and for example, a photopolymerization initiator may be irradiated with light having an appropriate wavelength.
If the polymerization initiator reacts at a low temperature, the polymerization of the monomer may start at the same time as absorption into the seed polymer, but it is better to start the polymerization after the absorption has been completed. Is more desirable because there is no danger of polymerizing by itself to form particles with a small particle size.

The polymerization time is such that the absorbed monomer is completely polymerized, and generally 0.1 to 30 hours is appropriate. The method of the present invention may be carried out in only one step, or may be carried out in a plurality of steps until it grows to a predetermined grain size. The produced polymer generally has a particle size of 1 to 30 μm, especially 5 to 20 μm, and is characterized by being highly monodisperse. The obtained polymer particles are separated by filtration, washed with water if necessary, and then dried to obtain a toner product. Toner particles are sprinkled with carbon black, hydrophobic silica, silicone oil, etc., if necessary, to obtain a final toner. .

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example 1) Styrene 20 ml, deionized water 36 ml, ethanol 144 ml,
Azobisisobutyronitrile 284mg and polyacrylic acid 2
The mixed solution of g was placed in a three-necked separable flask equipped with a reflux condenser, and the reaction was carried out at 70 ° C. for 12 hours while stirring at 100 rpm in a nitrogen stream to complete the polymerization. The polymer was observed by an optical microscope and found to be monodisperse particles of about 2 μm. Polymer 4g thus synthesized ethanol 600g, styrene 30g, polyacrylic acid 1.5g, spirone black 1.5g,
And 15 g of 2,2'-azobis (2,4-dimethylvaleronitrile) were dispersed to obtain an emulsion. This is made into an emulsion. 100 g of ethanol, 1,5 g of carbon black, and 0.05 g of polyallyl alcohol are added and sufficiently dispersed using a ball mill to make a suspension. As shown in FIG. A cellulose acetate film 4 was provided on the outside of the container 3 and was attached to the upper end 3a of the container 3 with a vinyl tape. This container was gently inserted into a water tank 2 containing ion-exchanged water 1 and a stirring device 5 was provided. When the above emulsion and suspension are injected into the container 3 while vigorously rotating the stirring device 5 before water enters the cellophane, the ion-exchanged water 1 in the water tank 2
Entered the container 3 and the water level in the container 3 rose sharply.

When the emulsion was observed under an optical microscope in this state, the particles were swollen into black particles of about 8 μm. This emulsion was placed in a 2 liter, 3-neck separable flask equipped with a reflux condenser, and stirred at 100 rpm under a nitrogen stream at 70 ° C.
The reaction was allowed to proceed for 8 hours to complete the polymerization reaction.

The polymer obtained from the above reaction was filtered and dried to 30
G toner was obtained.

When the particle size distribution of this toner was measured with a Coulter counter, as shown in Table 1, the particles were very monodisperse and spherical particles having an average particle size of 7.8 μm.

Further, when the above toner was put into an electrophotographic copying machine DC2055 (manufactured by Mita Kogyo Co., Ltd.) to form an image, a clear image was obtained.

(Example 2) 14 ml of styrene, 6 ml of butyl acrylate, 36 m of ion-exchanged water
l, ethanol 144 ml, azobisisobutyronitrile 282 m
g and 2 g of polyacrylic acid were placed in a 300 ml three-neck separable flask equipped with a reflux condenser, and reacted at 70 ° C. for 12 hours while stirring at 100 rpm under a nitrogen stream to complete the polymerization.
When the polymer was observed with an optical microscope, it was found to be monodisperse particles of about 2 μm.

5 g of the polymer obtained above, 600 g of methanol, ion-exchanged water
600g, 33g styrene including 1.5g grafted carbon black grafted with styrene, 1g spirone black, 1.5g polyvinylpyrrolidone and benzoyl peroxide
A 1.5 g solution was dispersed to obtain an emulsion.

As shown in FIG. 2, the U-shaped tube 10 is attached to the cellulose diacetate membrane 11
Then, ion-exchanged water is injected from one side, and the emulsion is injected from the other side at the same time. A pressure of 10 g / cm ² is applied to the ion-exchanged water side, and a stirrer piece 12 is put on the emulsion side and stirred with a magnetic stirrer 13. When the water level on the emulsion side stopped rising, the emulsion was observed with an optical microscope, and the particles were spherical with a black color of about 14 μm.
Was swollen. 2 l of this emulsion with a reflux
Put in a 3-neck separable flask and under a nitrogen stream at 100 rpm
The reaction was carried out at 70 ° C. for 8 hours with stirring to complete the polymerization. The polymer was filtered and dried to obtain 30 g of toner.

Further, when the particle size distribution of the toner particles was measured by a Coulter counter, as shown in Table 2, the particles were very monodisperse and spherical particles having an average particle size of 13.4 μm.

Further, when the above toner was put into an electrophotographic copying machine DC2055 (manufactured by Mita Kogyo Co., Ltd.) to form an image, a clear image was obtained.

(Example 3) 20 ml of styrene, 36 ml of deionized water, 144 ml of ethanol,
A solution of 284 mg of 2.2'-azobisisobutyronitrile and 2 g of polyacrylic acid was placed in a 300-ml three-neck separable flask equipped with a reflux condenser, and the polymerization was completed in the same manner as in Example 1. When the polymer was observed with an optical microscope, it was found to be monodisperse polymer particles of about 1 μm.

35 g of the polymer obtained above was added to 35 g of ethanol and 6 g of ion-exchanged water.
An emulsion was obtained by dispersing it in a solution consisting of 0 g, 30 g of methyl methacrylate, 3 g of oil-soluble dye (CI Solvent Red 27), 1.5 g of lauryltrimethylammonium chloride, and 1 g of 2.2 '-(2.4-azobisisobutyronitrile). .

As shown in FIG. 3, ion-exchanged water 21 is put in the water tank 20, and the central part of the cellophane tube (made by Wako Pure Chemical Industries, Ltd.) 22 is put in the water tank.
It was submerged in 20 and the above emulsion was injected from one end. The liquid flowing out from the other end was taken in a beaker and observed with an optical microscope. As a result, the particles swelled to a spherical shape of about 10 μm and showed a red color.

This emulsion was placed in a 2 liter, 3-neck separable flask equipped with a reflux condenser and stirred at 100 rpm under a nitrogen stream.
Polymerization was completed by reacting at 80 ° C. for 9 hours. The toner particles obtained by filtering the polymer and then drying the particles are true spherical red particles, and the particle size distribution is extremely monodisperse as shown in Table 3. When this toner is used, a red clear copy image is obtained. was gotten.

(Example 4) Polystyrene resin was crushed and classified to obtain 5% of 1.45 μm or less.
Then, resin particles having an average particle size of 1.67 μm with a particle size distribution of 83% for 1.45 to 1.85 μm and 12% for 1.85 μm or more were obtained. 600 g of ethanol with this resin particle 4, 30 g of styrene, 1.5 g of carbon black previously surface-treated with dodecylamine in methanol, 1.5 g of polyvinyl alcohol, 1.0 g of spirone black and 2.2'-azobis- (2.4-dimethylvaleronitrile) 1.5 g was mixed and dispersed to obtain an emulsion.

Next, the cellulose acetate membrane in the apparatus used in Example 1 was changed to an ethylene-vinyl alcohol copolymer membrane, and the particles in the emulsion were swollen.

When the emulsion was observed with an optical microscope in this state, the particles were swollen by about 11 μm. Place this emulsion in a 2 liter, 3-neck separable flask with a reflux condenser,
Polymerization was completed by reacting at 70 ° C. for 8 hours while stirring at 100 rpm in a nitrogen stream. The toner particles obtained by filtering the polymer and drying it were spherical toners, and the particle size distribution was extremely monodisperse as shown in Table 4. A clear copy image was obtained using this toner.

(Example 5) 600 g of ethanol, 600 g of water, 28 g of styrene, 5 g of spirone black, 1.5 g of polyacrylic acid, in which particles insoluble in water and ethanol were completely removed by distillation or ultrafiltration.
And a solution consisting of 1.5 g of benzoyl peroxide, an average particle size of 0.
1.8 mg of 2 μm monodisperse molybdenum oxide particles (manufactured by Nippon Shokubai Kagaku Kogyo) were dispersed to obtain a suspension.

Next, in the apparatus used in Example 2, the cellulose diacetate membrane was replaced with a polybenzoxazinedione membrane to increase the concentration of water in the suspension. When this suspension was observed with an optical microscope, black oil droplets of about 12 μm were growing.

The above suspension was placed in a 2 liter, 3-neck separable flask equipped with a reflux condenser while stirring at 100 rpm under a nitrogen stream.
The reaction was carried out at 70 ° C. for 8 hours to complete the polymerization. The polymer was filtered and dried to obtain 27 g of toner.

When the particle size distribution of the obtained toner particles was measured with a Coulter counter, they were very monodisperse spherical particles having an average particle size of 12.0 as shown in Table 5. A clear copy image was obtained using this toner.

Example 6 1.4 g of silica [AEROSIL130] (manufactured by Nippon Aerosol) having an average particle size of 20 nm was dispersed in distilled water 1. 600 ml of isopropyl alcohol from which particles insoluble in water and ethanol were completely removed by distillation or ultrafiltration, 700 g of water, 40 g of methyl methacrylate, 3 g of oil-soluble dye (CI Solvent Blue 7), 1.5 g of polyvinylpyrrolidone, benzoyl peroxide 1 ml of the above suspension in a solution consisting of 1.5 g
Was dispersed to obtain a suspension.

Next, after increasing the concentration of water in the suspension by the same method as in Example 1, the suspension was observed with an optical microscope. As a result, blue oil droplets of about 10 μm were growing. This suspension was placed in a 3 liter 3-neck separable flask and reacted at 70 ° C for 8 hours with stirring under a nitrogen stream.
The polymerization was completed. The polymer was filtered and dried to obtain 86 g of spherical toner.

The particle size distribution of the obtained toner was measured with a Coulter counter. As shown in Table 6, monodisperse spherical resin particles having an average particle size of 10.1 μm were obtained. When this toner was used, a clear copy image was obtained. further,
When an image was formed using this toner on an OHP transparency, a light-transmitting blue image was obtained.

Example 7 30 g of spherical ferrite particles having an average particle size of 5 μm and having a particle size distribution shown in Table 7 (1) were dispersed in 100 g of distilled water in which 0.1 g of sodium dodecylbenzenesulfonate was dissolved by using a ball mill. It was Excess surfactant in this suspension is removed by dialysis, and distilled water is added to
It was 730g. In addition, ethanol 70
0 g, styrene monomer 30 g, polyvinyl alcohol 1.5
g, spirone black TRH 3 g and azobis- (2,4-dimethylvaleronitrile) 1.5 g were dissolved to obtain a suspension.

Next, when the concentration of water in the suspension was increased by the same method as in Example 1 and the suspension was observed with an optical microscope, black oil droplets of about 10 μm were formed. This suspension was placed in a 3 liter, 3-neck separable flask equipped with a reflux condenser and stirred under a nitrogen stream at 100 rpm.
The reaction was carried out at 70 ° C. for 8 hours to complete the polymerization.

The obtained polymer was filtered and then dried to obtain about 60 g of toner.

The particle size distribution of the obtained toner was measured by a Coulter counter, and as shown in Table 7 (2), the particle size distribution was satisfactory as a toner. Further, the electrophotographic copying machine DC2055 in which the above magnetic toner is modified into a one-component magnetic developer
A clear image was obtained when an image was formed in a modified machine (manufactured by Sanda Kogyo Co., Ltd.).

Example 8 4 g of phthalocyanine green having an average particle size of 5 μm and having a particle size distribution shown in Table 8 (1) was added to sodium lauryl sulfate.
It was dispersed in 100 g of distilled water in which 0.8 g was dissolved using a ball mill. Excessive surfactant in this suspension was removed by dialysis, and distilled water was further added to bring the total amount to 700 g. Next, 700 g of methanol, 30 g of methyl acrylate, 1.5 g of polyvinyl alcohol, 3 g of Bontron E-82 and 1.5 g of benzoyl peroxide were dissolved in this suspension.

Next, when the concentration of water in the suspension was increased by the same method as in Example 1 and the suspension was observed with an optical microscope, black oil droplets of about 10 μm were formed. This suspension was placed in a 3 liter, 3-neck separable flask equipped with a reflux condenser and stirred under a nitrogen stream at 100 rpm.
The reaction was carried out at 70 ° C. for 8 hours to complete the polymerization.

The obtained polymer was filtered and then dried to obtain about 60 g of toner.

When the particle size distribution of the obtained toner was measured with a Coulter counter, a satisfactory particle size distribution as a toner was shown as shown in Table 8 (2). Further, the electrophotographic copying machine DC2055 in which the above magnetic toner is modified into a one-component magnetic developer
A clear image was obtained when an image was formed in a modified machine (manufactured by Sanda Kogyo Co., Ltd.).

[Effect of the Invention] According to the method of the present invention, the monomer and the toner property imparting agent are cored by utilizing the solubility decrease of the monomer, the toner property imparting agent and the polymerization initiator in the specific solvent / dispersion medium. By forming oil droplets around the substance or absorbing it in the seed polymer, particles of a desired size can be efficiently formed within a short time, and selective polymerization of the monomer in the particles becomes possible. For,
It is possible to obtain a spherical electrostatic charge development-like toner having a fixing property, an electric detection property, a particle size of a practical toner size, and a monodisperse particle size distribution. As a result, the toner obtained by the manufacturing method of the present invention has good fluidity, and a toner having a small difference in various characteristics such as charging characteristics between particles can be obtained.

[Brief description of drawings]

1 to 3 show an embodiment of means for absorbing a monomer into seed polymer particles in the present invention. The reference numbers in the figure indicate the following contents. 4, 11, 22 …… Semi-permeable membrane 1, 21 …… Ion-exchanged water 5, 12 …… Stirrer

Claims (2)

[Claims] 1. A water-miscible organic solvent which dissolves a monomer but does not dissolve the polymer or a mixed solution of the water-miscible organic solvent and water is used as a solvent to stabilize the monomer, the nuclear material and the dispersion. A toner property-imparting agent such as a coloring agent and a colorant and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, and the dispersion system is brought into contact with water through a semipermeable membrane, whereby the core substance is mainly concentrated. A toner for developing an electrostatic charge image, characterized in that oil droplets composed of a toner property imparting agent such as a polymer, a polymerization initiator and a colorant are formed, and the monomers in the oil droplets are selectively polymerized. Method. 2. A water-miscible organic solvent which dissolves a monomer but does not dissolve the polymer or a mixed solution of the water-miscible organic solvent and water is used as a solvent, and the monomer is mixed with the monomer. On the other hand, seed polymer particles exhibiting swelling property, a dispersion stabilizer, a toner property-imparting agent such as a colorant, and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, and the dispersion system is mixed with water through a semipermeable membrane. By contacting with the seed polymer particles, a toner property-imparting agent such as a monomer and a colorant and a polymerization initiator are absorbed in the seed polymer particles, and the monomer absorbed in the seed polymer particles is selectively polymerized. A method for producing a toner for developing an electrostatic charge image, which comprises increasing the diameter of polymer particles.