JPH0211605A - Production of monodisperse polymer particle - Google Patents

Abstract

PURPOSE:To produce monodisperse polymer particles having particle diameters larger than several mum with high productivity, by using a specific water-miscible org. solvent as both a solvent and a dispersion medium for a monomer and supplying water to a disperse system through a water-absorbing member to increase the water content of the disperse system. CONSTITUTION:A monomer, a nucleating agent or seed polymer particles which swell by the monomer, a dispersion stabilizer and an oil-soluble polymn. initiator are dissolved or dispersed in a water-miscible org. solvent which dissolves the monomer but does not dissolve a polymer derived form the monomer, or in a mixture of said water-miscible org. solvent with water. By supplying water to the resulting disperse system through a water-absorbing member (e.g., a fabric-like member made from natural or synthetic fiber, or paper made from natural or synthetic material), thereby increasing the water content of the disperse system, oil droplet particles comprising oil-soluble matters including the monomer, the polymn. initiator, etc., with the nucleating agent being at the center of the particles are formed, or the seed polymer particles are allowed to absorb the monomer and the polymn. initiator. The monomer in the oil droplet particles or absorbed in the seed polymer particles is selectively polymerized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing monodisperse polymer particles, and more specifically, the present invention relates to a method for producing monodisperse polymer particles, and more specifically, the present invention relates to a method for producing monodisperse polymer particles, and more specifically, a method for producing monodisperse polymer particles with a monodisperse particle size distribution and a particle size that does not generate fine defective particles. The present invention relates to a method for producing spherical polymer particles of several μm or more.

[Conventional technology]

Conventionally, emulsion polymerization, suspension polymerization, and dispersion polymerization are known as methods for producing spherical polymer particles. Each of these polymerization methods is characterized by the resulting particle size, particle size distribution, and molecular weight. In the emulsion polymerization method, monodisperse fine particles of the target molecules are obtained, but the particle size is 1.

Only small particles smaller than Oum can be obtained. On the other hand, although suspension polymerization can produce particles with a large particle size of 10 μm or more, it is only possible to synthesize particles with a polydisperse particle size distribution. Furthermore, in dispersion polymerization, although there are reports of the synthesis of monodisperse particles with a particle size of about 7 μm, it is not easy to control the molecular weight and particle size of the polymer constituting the particles, and the amount of monodisperse particles that can be used is limited. The body is also limited.

To improve these shortcomings, the Journal of Polymer Science; Polymer Symposium 2,
225-240 (1985) describes a ``two-step swelling method J'' in which monodisperse particles synthesized by emulsion polymerization are swollen with an oligomer or solvent, and then swelled with a seven-layer polymer.
is proposed.

[Problem that the invention seeks to solve]

However, the above-mentioned prior art method requires a complicated means of two-stage swelling, and the swelling operation itself requires a long time, resulting in a lack of productivity.

If spherical polymer particles with a particle size on the order of several um to several tens of μm and a monodisperse particle size distribution can be obtained, they will have a sharp particle size distribution and do not require operations such as classification, so they can be used for electrophotography. It is expected to be used as a gap adjuster for toner liquid crystal display panels, standard particles for Coulter counters, column packing materials for chromatography, carriers for immunodiagnostics, bases for cosmetics, and other applications.

Therefore, an object of the present invention is to provide a method for producing monodisperse polymer particles having a particle size of several μm or more with good productivity.

Another object of the present invention is to shorten the solubility of the monomer in the dispersion medium by utilizing it to form monomer-containing oil droplets or to absorb the monomer in seed polymer particles. The object of the present invention is to provide a method that can efficiently produce large-sized monodisperse polymer particles within a short period of time.

[Failure to solve the problem]

A water-miscible organic solvent that dissolves the monomer but does not dissolve the polymer, or a mixture of the water-miscible organic solvent and water, is used as the solvent to dissolve the monomer, the nuclear material, or the monomer. Seed polymer particles exhibiting swelling properties, a dispersion stabilizer, and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, water is supplied to the dispersion system through a water absorbing member, and the cough nucleus substance is concentrated. Forming oil droplets consisting of a monomer and a polymerization initiator, or absorbing a monomer and a polymerization initiator into nuclide polymer particles,
The object of the present invention is achieved by selectively polymerizing monomers in the oil droplets or monomers absorbed in the seed polymer particles to produce polymer particles.

[Effect]

The present inventors previously reported in Japanese Patent Applications No. 17321/1982 and 94284/1983 that they increased the concentration of water in the dispersion system to reduce the solubility of monomers in the dispersion system, and The monomer is precipitated into oil droplet particles consisting of a monomer and a polymerization initiator, or the monomer and the polymerization initiator are absorbed into the seed polymer particles, and the seed polymer particles are swollen. The particle size is increased to several microns or more, and the monomer in the oil droplet particles or the monomer absorbed in the seed polymer particles is selectively polymerized to form spherical particles with a particle size of several μm or more. A method for producing monodisperse polymer particles was proposed.

As a result of further investigation, the present inventors found that in order to increase the concentration of water, the method of simply dropping water into the dispersion system,
Because it is not evenly and uniformly supplied to the entire dispersion system, there are areas around the dropped water where the concentration of water is locally high, and the monomers in those areas are surrounded by water with which they have no affinity. ,
- Formation of oil droplet particles or swelling of seed polymer particles occurs, and only some particles around the water droplets grow, and eventually only those particles have a particle size that is smaller than that of other particles. It was discovered that if the concentration gradient of the layer increases, the monomer will precipitate in places other than the core material and seed polymer particles, forming oil droplets.

Therefore, in the present invention, the extreme concentration gradient of the dispersion system is eliminated by supplying water to the dispersion system through a water-absorbing member such as various cloths, papers such as filter paper, etc. Monomers are precipitated or absorbed only in the core material or seed polymer particles, thereby allowing the particles to grow more monodispersely.

In other words, when one end of the absorbent member is immersed in the aqueous phase to absorb water and the other end is immersed in the dispersion system, the water absorbed in the absorbent member gradually oozes out from the absorbent member into the dispersion system, causing extreme It quickly penetrates the entire dispersion system without creating a concentration gradient. In addition, since the contact area (surface area) between water and the dispersion system can be large, water can be efficiently supplied to the dispersion system, and the precipitated monomers can be quickly precipitated around the core substance, or The particles that grow after being absorbed by the seed polymer particles become monodisperse with uniform particle size.

In the present invention, it is important that polymerization is initiated selectively only for monomers absorbed in the oil droplets or in the seed polymer, and if polymerization is initiated for monomers dissolved in the dispersion medium. Then, the monomer is absorbed into the resulting polymer particles, causing particle growth, making it difficult to obtain monodisperse polymer particles.The polymerization initiator is oil-soluble, and the monomer is absorbed by the monomer. It needs to be absorbed into the oil droplet particles or seed polymer particles. In addition, when an oil-soluble substance is dissolved together with the nuclear material, seed polymer particles, dispersion stabilizer, polymerization initiator, etc., it forms oil droplets with other oil-soluble substances or is absorbed by the seed polymer and generated. For example, when an oil-soluble dye is dissolved, colored particles can be obtained.

[Preferred aspect]

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. monomers, vinyl ether monomers, diolefin monomers, monoolefin monomers, halogenated olefin monomers, polyvinyl monomers, and the like.

The monovinyl aromatic monomer has the following formula (wherein R8 is a hydrogen atom, a lower alkyl group, or a halogen atom, and R2 is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group, a vinyl or carboxyl group), such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene,
Examples of o-1m-1p-chlorostyrene, p-ethylstyrene, sodium styrene sulfonate, and divinylbenzene may be used alone or in combination of two or more, and other monomers mentioned above include the following: Each can be mentioned.

Formula butyl acrylate, 2-ethylhexyl acrylate,
cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, butyl T-hydroxylate, butyl δ-hydroxylacrylate, ethyl β-hydroxymethacrylate, T
-aminopropyl acrylate, T-N+ N-diethylaminopropyl acrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, etc.

An acrylic monomer of the formula (wherein R1 is a hydrogen atom or a lower alkyl group, R4 is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms, a hydroxyalkyl group, a vinyl ester group, or an aminoalkyl group); For example, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, (wherein R1
is a hydrogen atom or a lower alkyl group), such as vinyl formate, vinyl acetate, vinyl propionate, etc.

Vinyl ethers of the formula (wherein R6 is a monovalent hydrocarbon group having up to 12 carbon atoms), such as vinyl methyl ether, vinyl ethyl ether, vinyl-n-butyl ether 1. Vinyl phenyl ether, vinyl cyclohexyl ether, etc.

Diolefins of the formula (wherein each of R7, Rs, and R9 is a hydrogen atom, a lower alkyl group, or a halogen atom),
Especially butadiene, isoprene, chlorobrene, etc.

Monoolefins, especially ethylene, propylene, isoprene, butene-1, pentene-1,4-methylpentene-1, etc. (in the formula, each of R9° and R11 is a hydrogen atom or a lower alkyl group) .

Examples of halogenated olefin monomers include vinyl chloride, vinylidene chloride, etc., and examples of polyvinyl monomers include divinylbenzene, diallylphthalate,
Triallyl cyanurate and the like can be mentioned.

These monomers can be used alone or in combination of two or more. Preferred monomers are styrene, (meth)acrylate, styrene/(meth)acrylate, styrene/divinylbenzene.

Examples of water-miscible organic solvents for direct I1 include methanol, ethanol,
Lower alcohols such as isopropanol; polyhydric alcohols such as ethylene glycol, propylene glycol, phthanediol, diethylene glycol, and triethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as a7tone and methyl ethyl ketone; tetrahydrofuran, etc. Ethers; esters such as ethyl acetate; organic acids such as formic acid, acetic acid, propionic acid, etc. Among these, those that dissolve the monomer but do not dissolve the polymer are considered monomers. used in combination. Organic solvents that have excellent monomer solubility, can be mixed with water in any ratio, and are therefore particularly useful for the purposes of the present invention include:
It is a lower alcohol such as tanol.

This water-miscible organic solvent can be used alone or
It can also be used in the form of a mixture with water.

In the latter case, it is desirable to contain as much water as possible without practically reducing the solubility of the monomer.
The mixing ratio is determined by the monomer and organic solvent used.
For example, when lower alcohol is used as the organic 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.

Thatch soil 1 The core substance used in the present invention is a substance that serves as a nucleus when monomers precipitated by utilizing the decrease in monomer solubility in a specific solvent and dispersion medium form oil droplets, and at the same time It acts as the core of the polymer.

This nuclear material may be any conventionally known fine particles, such as Al2O3,
Mn0z, 5iOz, Snug, Th0z, TiO2,
Examples include ZnO2Mob, KO5, silica, gold, silver, inorganic pigments, organic pigments, and magnetic powder.

Among these, when magnetic powder is used as a nuclear material, magnetic particles can be obtained. Magnetic powders include ferromagnetic metals such as iron, cobalt, and nickel, or magnetite,
Alloys and compounds such as hematite and ferrite are used.

Further, when carbon black, an inorganic pigment, or an organic pigment is used as a core material, colored particles can be produced without adding any coloring agent. As the pigment, commonly used pigments can be used.

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

113d11 beads The seed polymer particles used in the present invention exhibit swelling properties with respect to the above-mentioned monomers, and are polymer particles obtained by polymerizing one or more of the above-mentioned monomers. . These polymer particles are generally formed from the same type of monomer as the monomer used, but they may also be formed by polymerizing a monomer different from this monomer. An example is a combination of styrenic polymer particles and a styrenic monomer, and an example of the latter is a combination of acrylic polymer particles and a styrenic monomer.

The seed polymer particles have a monodisperse particle size distribution,
It is desirable that the particle size is generally in the range of 0.01 to 50 μm, particularly 0.5 to 20 μm. Such seed polymer particles can be produced by a dispersion polymerization method, an emulsion polymerization method, or a polymer polymerization method known per se. It can be easily obtained by crushing and classifying.

As a dispersion stabilizer for improving the dispersibility of seed polymer particles in a solvent/dispersion medium, polyvinyl alcohol, methyl cellulose, ethyl cellulose, etc., which are known per se, are used.
Polymer dispersion stabilizers such as polyacrylic acid, polyacrylimide, polyethylene oxide, poly(hydroxystearate-g-methyl methacrylate-co-methacrylic acid) copolymers, nonionic surfactants, and anionic interfaces. Active agents, cationic surfactants, amphoteric surfactants, etc. are used.

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

Any oil-soluble polymerization initiator can be used as the single gold plate violet plate polymerization initiator. For example, as a radical polymerization initiator,
Can be used with monomers such as azo compounds such as azobisisobutyronitrile, peroxides such as cumene hydroperoxide, L-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, and lauroyl peroxide. A soluble one is used. Furthermore, in the case of polymerization using ultraviolet rays, oil-soluble photopolymerization initiators among known photopolymerization initiators can be used. Among oil-soluble initiators, it is particularly desirable to use a polymerization initiator that is difficult to dissolve in an organic solvent so that the monomer is difficult to polymerize alone in an organic solvent.

According to the present invention, first, a monomer is dissolved in a water-miscible organic solvent or a mixture thereof with water. The amount of monomer dissolved varies considerably depending on the type and composition of the solvent and monomer, but is generally 0.01 to 50% by weight, particularly 1 to 20% by weight.
Weight % ranges are preferred.

This solution contains a core material or seed polymer particles, a dispersion stabilizer,
and a polymerization initiator. The amounts of nuclear material and seed polymer particles added vary depending on the desired particle size. That is, most of the monomers present in the system are distributed by the number of core materials or seed polymers, so that the monomers necessary to form particles of the desired particle size are distributed by the number of core materials or seed polymers. Coalescence - It is necessary to determine the amount of nuclear material and seed polymer added so that they are distributed per unit. Generally, the ratio between the core material or seed polymer particles and the monomer in the system is 1:1 to 1:109, especially 1:1.
Preferably, they are present in a weight ratio of 0 to 1:10', while the concentration of seed polymer particles in the dispersion is generally in the range of 0.01 to 50% by weight, in particular 0.1 to 20% by weight. It is better. Further, the dispersion stabilizer may be used in an amount of 0.1 to 30% by weight per seed polymer particle, especially 1 to 10 ft1.
%, while the polymerization initiator is preferably used in an amount of 0.001 to 10% by weight, especially 0.01 to 0.5% by weight, based on the monomers charged.

Then, water is supplied through the water absorbing member during the above dispersion. Examples of the water absorbing member used in the present invention include cloth-like members made of natural or chemical fibers and papers produced from natural or chemical raw materials, which are porous and capable of uniformly supplying water to the dispersion system. Preferably. The amount of water supplied to the dispersion is generally 0.5 mf for a dispersion capacity of 100 mf.
Preferably it is from 1 to 10 mQ/min, especially from 0.5 to 5 mff.

At this time, solubility may be reduced by lowering the temperature of the system.

Because the above-mentioned treatment progresses uniformly and rapidly throughout the entire dispersion system as described above, each particle grows uniformly in an extremely short period of time, resulting in particles exhibiting a more monodisperse particle size distribution. At this time, the polymerization initiator is also absorbed at the same time as the monomer is absorbed.

Then, the monomers absorbed into the polymer particles or the monomers in the oil droplets formed around the core material are polymerized. Polymerization is carried out at -g in an inert atmosphere such as nitrogen at -30°C to 9°C.
It is carried out at a temperature of 0°C, in particular from 30°C to 80°C.

Polymerization conditions vary depending on the type of polymerization initiator; for example,
If it is a photopolymerization initiator, it may be irradiated with light of an appropriate wavelength. If the polymerization initiator is one that reacts at low temperatures, monomer polymerization may begin simultaneously with absorption into the seed polymer;
It is more desirable to start polymerization after absorption is complete, since there is no risk that the monomer will polymerize on its own to form particles with a small size.

The polymerization time is such that the polymerization of the absorbed monomer is completed, and a suitable time for -i is 0.1 to 30 hours. The method of the present invention may be carried out in only one stage, or may be carried out in multiple stages until the grains are grown to a predetermined size. The resulting polymer generally has a particle size of 1 to 1000 μm, especially 5 to 1 μm.
00 μm, and is characterized by being highly monodisperse. The obtained polymer particles can be used for various purposes in the form of a suspension, or can be separated by filtration.
After washing with water if necessary, it can be used in powder form for various purposes.

〔Example〕

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

(Example 1) Styrene 20#11! A mixed solution of 36 d of ion-exchanged water, 144 d of ethanol, 284 d of azobisisobutyronitrile, and 2 g of polyacrylic acid was placed in a 3-necked separable flask equipped with a reflux device, and heated at 1100 rpm under nitrogen flow.
The reaction mixture was stirred at 70°C for 12 hours to complete the polymerization. When the polymer was observed with an optical microscope, it was found to be monodisperse particles of about 2 μm. 4 g of the polymer synthesized in this way was mixed with 700 g of ethanol and 70 g of ion-exchanged water.
0 g, 30 g of styrene, 15 g of polyvinyl alcohol, and 15 g of 2,2''-azobis(2,4-dimethylvaleronitrile) to obtain an emulsion.

The emulsion obtained above was placed in the reaction tank 1 shown in FIG. 1, and both ends of the gauze 3 were immersed in the reaction tank 1 in which the beaker 2 and the emulsion 4 were stored. Emulsion 4 was stirred with a stirring rod 5, and 2000 ml of water was put into beaker 2, and the water passed through gauze 3 and was supplied to emulsion 4. The water in beaker 2 is about 1000m after 15 minutes! !
, the water was decreasing. At this time, when the emulsion was observed with an optical microscope, the particles were swollen to 8 μm.

Then, the emulsion was placed in a 32x triple-lowerable flask equipped with a reflux device and heated at 1100 rpm under a nitrogen stream.
The reaction was carried out at 70° C. for 8 hours while stirring to complete the polymerization. After filtering the obtained polymer, it is dried to give about 2
8 g of resin particles were obtained.

The particle size distribution of the obtained particles was measured using a Coulter counter, and as shown in Table 1, they were extremely monodisperse and spherical particles with an average particle diameter of 7.6 μm.

Table 1 (Pulling and Walking 2) Styrene 14d, butyl acrylate 6m, ion-exchanged water 36d, ethanol 144, azobisisobutyronitrile 280mg, and polyacrylic acid 2g were placed in a 300d vessel equipped with a reflux device. 3 were placed in a rosetteable flask and reacted at 70°C for 12 hours while stirring at 1100 rpm under a nitrogen stream. When the polymerized product was observed with an optical microscope, it was found to be monodisperse particles of about 2 μm. there were.

An emulsion was obtained by dispersing 4 g of the polymer obtained above in a solution consisting of 700 g of methanol, 700 g of ion-exchanged water, 150 g of styrene, 3 g of polyvinyl alcohol, and 15 g of benzoyl peroxide.

The emulsion obtained above was placed in the reaction tank 1 shown in FIG. 1 and water was supplied in the same manner as in Example 1.

When the emulsion at this time was observed with an optical microscope, the particles were swollen to 14 μm.

Next, transfer the emulsion to a reflux device. Place the three in a separable flask and heat at 1100 rpm under a nitrogen stream.
The reaction was carried out at 70°C for 8 hours without stirring, and the polymerization was completed. After filtering the obtained polymer, it is dried to give about 1
50 g of resin particles were obtained.

The particle size distribution of the obtained particles was measured using a Coulter counter, and as shown in Table 2, they were extremely monodisperse and spherical particles with an average particle diameter of 7.6 μm.

Table-2 (1. Joo, Zugg) (Example 3) Styrene 2011! , ion exchange water 361d, ethanol 144d, 2,2゛-azobisisobutyronitrile 2
A solution of 4 g of polyacrylic acid and 4 g of polyacrylic acid was placed in three separate 300II11 flasks equipped with a reflux device, 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.

4 g of the polymer obtained above was mixed with 350 g of ethanol, 600 g of ion exchange water, 400 g of methyl methacrylate,
Oil-soluble dye (C01, Solvent Red 27) 30g
, 2.2'-(2,4-azobisisobutyronitrile) 10 g to obtain an emulsion.

The concentration of water in the emulsion obtained above was increased using the same operations and conditions as in Example 1. When the emulsion was observed under an optical microscope, the particles were 10 μm in size.
It was swollen.

Then, the emulsion was placed in a 31-piece rosemovable flask equipped with a reflux device and heated at 1100 rpm under a nitrogen stream.
The reaction was carried out at 70° C. for 8 hours while stirring to complete the polymerization. After filtering the obtained polymer, it is dried and
00 g of red resin particles were obtained.

The obtained particles are true spherical red particles, and the particle size distribution is extremely monodisperse as shown in Table 3, with an average particle size of 9.4.
They were spherical particles of μm in size.

Table 3 (hereinafter referred to as blank space) (Example 4) Silica with an average particle size of 20 μm (AEROSIL 130
(manufactured by Nippon Aerosil Co., Ltd.)) 1 mg was dispersed in distilled water IP. Isopropyl alcohol 600mf completely removes unnecessary particles from water and alcohol by distillation or ultrafiltration! , 0.3 mj2 of the above silica suspension was added to a solution consisting of 700 mj2 of water, 40 g of methyl methacrylate, 1.5 g of polyvinylpyrrolidone, and 1.5 g of benzoyl peroxide.

The suspension obtained above was subjected to the same operations and conditions as in Example 1 to increase the concentration of water.

When this was observed with an optical microscope, the particle size was approximately 10 μm.
droplets were generated.

Next, the emulsion was placed in a three-necked separable flask equipped with a reflux device, and heated at 1100 rpm under a nitrogen stream.
The reaction was carried out at 70°C for 8 hours without stirring to complete the polymerization. After filtering the obtained polymer, it is dried and
0 g of resin particles were obtained.

The particle size distribution of the obtained particles was measured using a Coulter counter, and as shown in Table 4, they were extremely monodisperse and spherical particles with an average particle diameter of 10.1 μm.

Table 4 (Example 5) 3 g of spherical ferrite particles with an average particle size of 5 μm and having the particle size shown in Table 5 (1) were ball milled into 100 g of distilled water in which 0.1 g of sodium dodecylbenzenesulfonate was dissolved. It was dispersed using

Excess surfactant in this suspension was removed by dialysis, and distilled water was added to bring the total amount to 700 g. Further, 700 g of ethanol, 30 g of styrene monomer, 1.5 g of polyvinylal:7-ol, and 1.5 g of azobis(2,4-bimethylvaleronitrile) were dissolved in this suspension to obtain a suspension.

The suspension obtained above was subjected to the same operations and conditions as in Example 1 to increase the concentration of water.

When this was observed with an optical microscope, droplets containing one ferrite particle were formed.

Next, the emulsion was placed in a three-necked separable flask equipped with a reflux device, and reacted at 70° C. for 8 hours while stirring at 1100 rpm under a nitrogen stream to complete polymerization. After filtering the obtained polymer, it is dried to give about 30g.
magnetic resin particles were obtained.

The particle size distribution of the obtained magnetic particles was measured using a Coulcoo counter, and as shown in Table 5 (2), they were extremely monodisperse, with an average particle size of 10 μm.

They were spherical particles of 5 μm.

Table 5 (1) Table 5 (Example 6) 4 g of phthalocyanine green having the particle size distribution shown in Table 6 (1) with an average particle size of 5 μm was dissolved in 100 g of distilled water with 0.8 g of sodium lauryl sulfate dissolved therein. It was dispersed using a ball mill. Excess surfactant of this subenzidine 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, and 1.5 g of benzoyl peroxide were dissolved in this suspension.

The suspension obtained above was subjected to the same operations and conditions as in Example 1 to increase the concentration of water.

When this was observed with an optical microscope, the particle size was approximately 10 μm.
Droplets containing one green pigment were formed. Next, the emulsion was placed in a three-necked separable flask equipped with a reflux device, and the mixture was reacted at 70° C. for 8 hours while stirring at 1100 rpm under a nitrogen stream to complete the polymerization. The obtained polymer was filtered and dried to obtain about 30 g of green resin particles. The particle size distribution of the obtained green particles was measured using a Coulter counter and Table 6 (
2), it is very monodisperse, with an average particle size of 10.
They were spherical particles of 5 μm.

Table 6 (1) (Effects of the invention) According to the present invention, by supplying water to the dispersion system through the water absorption part, the contact area with the water system increases, and the water is supplied to the dispersion system through the water absorption part. Penetration of water occurs evenly and uniformly throughout the system, and the monomers are precipitated or absorbed only in the material or seed polymer particles without causing a local increase in water concentration, resulting in extremely monodisperse Particle growth occurs efficiently within a short period of time. By selectively polymerizing the monomer components of the grown particles thus obtained, monodisperse polymer particles having a particle size of several μm or more are obtained, and these polymer particles are used in electrophotographic toners. , gap adjuster for liquid crystal display panels,
It can be used as standard particles for Coulter counters, column packing materials for chromatography, etc.

[Brief explanation of the drawing]

FIG. 1 shows a reaction apparatus showing one embodiment of the present invention. 1... Reaction tank 2... Water tank, 3... Gauze Patent applicant Sanda Kogyo Co., Ltd.

Claims (2)

[Claims] (1) A water-miscible organic solvent that dissolves the monomer but does not dissolve the polymer or a mixture of the water-miscible organic solvent and water is used as the solvent, and the monomer, the core substance, the dispersion stabilizer, and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, and water is supplied to this dispersion system via a water absorption member to increase the concentration of water in the dispersion system, so that the core substance is mainly A method for producing monodisperse polymer particles, which comprises: forming oil droplet particles consisting of an oil-soluble substance such as a monomer and a polymerization initiator, and selectively polymerizing the monomers in the oil droplet particles. . (2) Using a water-miscible organic solvent that dissolves the monomer but does not dissolve the polymer, or a mixture of the water-miscible organic solvent and water as a solvent, seed polymer particles exhibiting swelling properties;
A dispersion stabilizer and an oil-soluble polymerization initiator are dissolved or dispersed in the solvent, and water is supplied to this dispersion system through a water absorbing member to increase the concentration of water in the dispersion system to increase the seed weight. A method for producing monodispersed polymer particles, which comprises absorbing a monomer and a polymerization initiator into the combined particles, and selectively polymerizing the monomers absorbed into the seed polymer particles.