JPH1160618A - Spherical polymer particle and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain spherical polymer particles having a narrow particle diameter distribution and precisely controlled molecular weight distribution by using seed particles comprising spherical polymer particles different in maximum molecular weight and enlarging the seed particles. SOLUTION: One or more polymerizable vinyl monomers selected from unsaturated carboxylic acids, (meth)acrylic esters, (meth)acrylamide derivatives, styrene and alkyl- or halogen-substituted derivative thereof, vinyl esters, vinyl ethers, allyl alcohol and esters or ether thereof, and the like, are polymerized in the presence of a radical polymerization initiator to give seed particles comprising spherical polymer particles having a coefficient of variation of mean particle diameter of at most 10% and different in maximum molecular weight. A polymerizable vinyl monomer is polymerized in the presence of the seed particles to enlarge the seed particles, thus giving spherical polymer particles having a mean particle diameter of 0.1-20 μm and a molecular weight of 2,000 to 1,000,000, with at least two maximum values of molecular weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to spherical polymer particles and a method for producing the same. More specifically, the present invention relates to a spherical polymer particle used for a coating material, a paper coating material, a toner, a liquid crystal spacer, a cosmetic material, a diagnostic reagent carrier, a chromatography filler, and the like, and a method for producing the same.

[0001]

2. Description of the Related Art Conventional methods for producing spherical polymer particles include a suspension polymerization method, an emulsion polymerization method and a dispersion polymerization method. The suspension polymerization method is a method in which dispersed oil droplets of a polymerizable vinyl monomer are formed by mechanical stirring in water containing a dispersant, and polymerization is performed using an oil-soluble polymerization initiator. The emulsion polymerization method is a method in which a polymerizable vinyl monomer is polymerized in a surfactant micelle using a water-soluble polymerization initiator.

The dispersion polymerization method is a method in which a polymerizable vinyl monomer is dissolved in a medium in which a produced polymer is not dissolved, using a polymerization initiator soluble in the medium, to polymerize the monomer.
When producing spherical polymer particles having an average particle diameter of 0.1 to 20 μm and a narrow particle diameter distribution, the spherical polymer particles produced by the suspension polymerization method may have an average particle diameter of 10 μm or less. It is industrially difficult, and only particles having a wide particle size distribution can be obtained.

Although spherical polymer particles produced by emulsion polymerization have a narrow particle size distribution, it is difficult to make the average particle size 1 μm or more due to the mechanism of polymerization. on the other hand,
The average particle diameter is 0.1 to 2 by using the dispersion polymerization method.
Although it is possible to produce spherical polymer particles having a narrow particle size distribution of 0 μm, deformation of the particle shape is restricted by the mechanism that particles are formed by precipitation of the polymer generated as the polymerization proceeds. The range of the polymerization system which does not cause the fluctuation of the average particle diameter and the widening of the particle diameter distribution is limited, and it is difficult to arbitrarily change the molecular weight of the spherical polymer particles produced in such a system.

In the case of producing spherical polymer particles having a low molecular weight and a high uniformity in particle size, for example, as disclosed in JP-A-64-1702 and JP-A-5-59109, mercaptan is used. Although a technique using a system chain transfer agent is known, this method only reduces the molecular weight as a whole, and it is difficult to precisely control the molecular weight distribution. In addition, JP-A-3-19090
As disclosed in Japanese Patent Application Publication No. 5 (1999) -2005, there is a technique using an azo-based hydrochloride as a polymerization initiator. Is difficult to do.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a paint raw material,
Raw materials for paper coating, toner, liquid crystal spacers, raw materials for cosmetics,
The present invention relates to a spherical polymer particle having a narrow particle size distribution and a precisely controlled molecular weight distribution used for a carrier for a diagnostic reagent, a chromatography filler, and the like, and a method for producing the same. More specifically, the number average particle diameter is in the range of about 0.1 to about 20 μm, the particle diameter distribution is narrow, and the molecular weight is 2,000 to 2,000.
The present invention relates to spherical polymer particles having two or more molecular weight maxima in the range of 1,000,000 and a method for producing the same.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have determined that a spherical polymer particle having a narrow particle size distribution is used as a seed particle, and a polymer having a different maximum molecular weight from the seed particle is used as the seed particle. By increasing the average particle diameter of about 0.1 ~
The present inventors have found that spherical polymer particles having a molecular weight range of about 20 μm, a narrow particle size distribution, and two or more molecular weight maxima in the molecular weight range of 2,000 to 1,000,000 can be produced. The invention has been completed.

That is, the gist of the present invention is that the molecular weight is 2,000.
It exists in spherical polymer particles having two or more molecular weight maxima in the range of １，1,000,000. Preferably, the average particle size is in the range of about 0.1 to about 20 μm, more preferably, the average particle size is in the range of about 0.1 to about 20 μm, and the coefficient of variation is 10% or less. And spherical polymer particles.

The gist of the present invention is to produce the above spherical polymer particles by using the spherical polymer particles as seed particles and enlarging the seed particles using a polymer having a different maximum molecular weight from the seed particles. There is also a method. In a preferred embodiment, the seed particles are seed particles having a coefficient of variation of an average particle diameter of 10% or less, a polymer having a different maximum molecular weight from the seed particles having compatibility with the seed particles, Particles and / or
Alternatively, a polymer having a different maximum molecular weight from the seed particles may be obtained by a polymerization reaction of the polymerizable vinyl monomer in a medium in which the polymerizable vinyl monomer dissolves but the generated polymer does not dissolve. No. Further preferably, the polymerization reaction of the polymerizable vinyl monomer is a polymerization reaction using a radical initiator in the medium. In addition,
For a polymer having a different maximum molecular weight from the seed particles, the use of the above-mentioned radical initiator and a chain transfer agent such as a monosulfide and / or a disulfide is a more preferable embodiment.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The spherical polymer particles of the present invention can be obtained by using the spherical polymer particles as seed particles and enlarging the seed particles using a polymer having a different maximum molecular weight from the seed particles. In addition,
Hereinafter, in the present invention, regarding the spherical polymer particles obtained in the present invention, "the spherical polymer particles of the present invention", and with respect to the spherical polymer particles used as seed particles, "the spherical polymer particles of the seed particles" And used separately.

First, the "spherical polymer particles as seed particles" will be described. "Seed particle spherical polymer particles" are composed of polymerizable vinyl monomers. Examples of such a polymerizable vinyl monomer include unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, and maleic acid; and (meth) acrylic acids such as methyl (meth) acrylate and ethyl (meth) acrylate. Alkyl ester, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, phenyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2- (meth) acrylate
(Meth) acrylates such as chloroethyl, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate;
(Meth) acrylamide derivatives such as (meth) acrylamide and N, N-dimethyl (meth) acrylamide; styrenes such as styrene, methylstyrene, α-methylstyrene, chlorostyrene and chloromethylstyrene and alkyl- or halogen-substituted products thereof; acetic acid Vinyl esters such as vinyl and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; allyl alcohol and its esters or ethers; (meth) acrylonitrile, vinyl sulfonic acid, p-styrene sulfonic acid, vinyl pyridine, vinyl pyrrolidone etc,
And other vinyl compounds. These polymerizable vinyl monomers can be used alone or in a mixture of two or more.

In the present invention, when the “spherical polymer particles of seed particles” are obtained by polymerizing a polymerizable vinyl monomer, a radical polymerization method, an anion polymerization method, a cationic polymerization method, or the like is used as a polymerization initiation method. However, a radical polymerization method is preferred from the viewpoint of control of polymerization and ease of industrial application. Examples of the initiator used in the radical polymerization method include 2,2′-azobisisobutyronitrile and 2,2′-azobis (2,2
4-dimethylvaleronitrile), 4,4-azobis (4
Azo polymerization initiators such as -cyanopentanoic acid); t-butyl hydroperoxide, di-t-butyl peroxide,
Benzoyl peroxide, di-isopropyl peroxydicarbonate, t-butyl peroxyisobutyrate and peroxide-based polymerization initiators such as hydrogen peroxide, potassium persulfate and ammonium persulfate, or a reducing agent such as amine and sodium bisulfite. Added system; and the like.

The seed particles are produced by a known method such as a suspension polymerization method, an emulsion polymerization method, and a dispersion polymerization method.
Emulsion polymerization and dispersion polymerization are preferred for obtaining seed particles having a narrow particle size distribution, and dispersion polymerization is particularly preferred for obtaining polymer particles having an average particle size of 0.1 to 20 μm.
(Also, a seed polymerization method may be used in combination with the above polymerization method in order to obtain a desired particle size.)

When the dispersion polymerization method is used in the method for producing the seed particles, the medium that dissolves the polymerizable vinyl monomer but does not dissolve the (co) polymer formed is used as the medium. It is appropriately selected in order to obtain a desired average particle size and particle size distribution of the particles. Specifically, alcohols such as methanol, ethanol, propanol, (di) ethylene glycol, propylene glycol, and glycerin; esters such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, and (di) ethylene glycol monoacetate; Ethers and ether alcohols such as diethyl ether, dioxane, tetrahydrofuran, (di) ethylene glycol monomethyl ether and (di) ethylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; hexane, cyclohexane, octane, benzene,
Hydrocarbons such as toluene and xylene; chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene,
Mediums such as halogenated hydrocarbons such as dichlorobenzene and chlorotoluene; nitrogen-containing compounds such as acetonitrile, dimethylamine, monoethanolamine, dimethylformamide, pyridine and nitrobenzene; sulfur-containing compounds such as carbon disulfide and dimethyl sulfoxide; Water can be used, and these can be used alone or in a mixture of two or more.

When a dispersion polymerization method is used in the production method of the seed particles, a dispersion stabilizer soluble in the above-mentioned medium is required in order to form spherical particles without agglomeration, deformation or fusion of the resulting polymer. It is preferable to use Examples of dispersion stabilizers include polyvinylpyrrolidone, polyacrylic acid, polyvinyl alcohol, polymethylvinylether, polyacrylamide, polyethyleneimine, and poly (2-ethyl-
Homopolymers such as 2-oxazoline), various random copolymers, graft copolymers, block copolymers,
Synthetic polymers such as macromonomers; natural polymer derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose; and the like. If desired, an auxiliary stabilizer can be used in addition to the above-mentioned dispersion stabilizer. Examples of such co-stabilizers include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and long-chain alcohols.

In the present invention, the “spherical polymer particles of seed particles” as described above are used as seed particles, and the seed particles are enlarged by using a polymer having a different maximum molecular weight from the seed particles. It is characterized in that spherical polymer particles having two or more molecular weight maxima in the molecular weight range of 2,000 to 1,000,000 are obtained. Polymers having a different maximum molecular weight from the seed particles that enlarge the seed particles may be used with or without compatibility with the seed particles, but the stability of the reaction system when the seed particles are enlarged is increased. Considering this, it is preferable to use a compatible polymer.

As a method for obtaining a polymer having a different maximum molecular weight from the seed particles which enlarge the seed particles, a seed polymerization method and a seed dispersion polymerization method are used. In the seed polymerization method, after the polymerizable vinyl monomer is absorbed by the seed particles, the polymerizable polymerizable vinyl monomer is polymerized to obtain enlarged polymer particles. Seed dispersion polymerization method is called Coll
oid & Polymer Science, 267
Vol., P193-200 (1989) and Colloid
& Polymer Science, 274, p2
79-284 (1996), in the presence of seed particles, a polymerizable vinyl monomer is dissolved in a medium in which the produced polymer is not dissolved, using a polymerization initiator soluble in the medium. This is a method for obtaining enlarged polymer particles by polymerizing a monomer. When a dispersion polymerization method is used as a method for producing seed particles, it is preferable to use a seed dispersion polymerization method since the steps can be performed continuously.

When a polymer having a maximum molecular weight different from that of the seed particles is obtained by polymerization of a polymerizable vinyl monomer, a radical polymerization method, an anion polymerization method, a cationic polymerization method or the like can be used as a polymerization initiation method. However, a radical polymerization method is preferred from the viewpoint of control of polymerization and ease of industrial application.

In the present invention, the polymer for enlarging the seed particles needs to have a different maximum molecular weight from the seed particles. When a polymer that enlarges the seed particles is obtained by polymerization of a polymerizable vinyl monomer, as a method of controlling the molecular weight, the amount of the polymerization initiator is changed, a chain transfer agent is added, Examples of such methods include changing the oxygen concentration, using a polymerization initiator having a different half-life in the case of the radical polymerization method, and the like.However, there is a method of adding a chain transfer agent that can easily control the molecular weight by adding a small amount. preferable.

Examples of the chain transfer agent include carbon tetrachloride, carbon tetrabromide, chloroform, bromoform, dichloromethane,
Halogenated hydrocarbons such as dibromoethane, dichloroethane, dibromoethane; allyl compounds such as allyl acetate, allyl chloride, allyl bromide; ethyl mercaptan, dodecyl mercaptan, mercaptoethanol, thioglycerol, mercaptoacetic acid, mercaptopropionic acid, thiomalic acid, etc. Thiocarboxylic acids such as thioacetic acid and thiobenzoic acid; monosulfides and disulfides;
In particular, examples of monosulfide and disulfide-based chain transfer agents include alkyl (di) sulfides such as ethyl (di) sulfide and butyl (di) sulfide; bis (dimethylthiocarbamoyl) sulfide, and bis (dimethylthiocarbamoyl). ) Bis (dialkylthiocarbamoyl) sulfides such as disulfide, bis (diethylthiocarbamoyl) sulfide, bis (diethylthiocarbamoyl) disulfide, and bis (dialkylthiocarbamoyl) disulfides; phenyl (di) sulfide, benzyl (di) sulfide and the like Aromatic (di) sulfides; and the like, preferably bis (dimethylthiocarbamoyl) sulfide, bis (dimethylthiocarbamoyl) disulfide, bis (diethylthiocarbamoyl) sulfide, Scan (diethyl thiocarbamoyl) bis such disulfide (dialkyl thiocarbamoyl) sulfide and bis (dialkyl thiocarbamoyl) disulfide and the like.

The addition ratio of these chain transfer agents is 0.01 to 19% by weight, preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, based on the polymerizable vinyl monomer. Percentage. When the addition ratio is less than 0.01% by weight, the effect of lowering the molecular weight becomes insufficient, and when it exceeds 19% by weight, the shape, average particle size and particle size distribution of the spherical polymer particles produced are adversely affected, and It is also uneconomical.

The production of the "spherical polymer particles of the present invention" in the present invention is usually carried out in a reactor equipped with a stirrer, a condenser, a thermometer and the like. In this case, the polymerization initiator and the chain transfer agent can be added at any time before the start of the temperature rise, during the temperature rise, and after the temperature reaches the polymerization temperature, and can be any of the batch addition method, the split addition method, and the continuous addition method. It is. Further, in order to improve the progress of the polymerization, it is preferable to set the inside of the reactor to an atmosphere of nitrogen, argon gas or the like. The polymerization temperature and the polymerization time are appropriately determined depending on the type and amount of the polymerizable vinyl monomer, the type and amount of the polymerization initiator, and the type and amount of the chain transfer agent. Minutes to 1440 minutes.

The “spherical polymer particles of the present invention” obtained by the above-mentioned method has an average particle diameter in the range of about 0.1 to about 20 μm, and the coefficient of variation is a value obtained by dividing the standard deviation thereof by the average particle diameter. Has a narrow particle size distribution of 10% or less.
In the present invention, the average particle size of the particles was measured by a particle size distribution measurement method described in Diaion Manual (Mitsubishi Chemical Corporation).

As for the molecular weight, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography was 2,000 to 1,000.
It has two or more molecular weight maxima in the range of 000. Such "spherical polymer particles of the present invention" are spherical polymer particles having a narrow particle size distribution and a precisely controlled molecular weight distribution.

[0024]

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

EXAMPLE 1 67.75 parts by weight of ethanol was placed in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, and polyvinylpyrrolidone (average molecular weight: 40,000) 1.8.
Parts by weight were added and dissolved. 30 parts by weight of glycidyl methacrylate and 0.45 parts by weight of 2,2-azobisisobutyronitrile were added to this solution, and the mixture was heated to 70 ° C. under a nitrogen atmosphere.
And polymerized for 3 hours to obtain a seed particle dispersion medium.

Next, 30 parts by weight of glycidyl methacrylate, 0.3 part by weight of 2,2-azobisisobutyronitrile, 0.3 part by weight of bis (diethylthiocarbamoyl) disulfide and polyvinylpyrrolidone (average molecular weight 40,000) ) 1.8 parts by weight were dissolved in 67.75 parts by weight of ethanol, and this solution was added to a seed particle dispersion medium, followed by heating at 70 ° C under a nitrogen atmosphere to carry out polymerization for 3 hours.
After cooling, the spherical polymer particles isolated by washing with methanol had an average particle size of 2.61 μm and a coefficient of variation of 5.8%.

The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. As a result, the molecular weight was reduced to 45,000 and 80,000 in the range of 2,000 to 1,000,000. There was a maximum.
The glass transition temperature of the spherical polymer particles was determined by DSC.
It was 60 ° C. when measured with an apparatus (SSC580DS: manufactured by SEIKO).

Comparative Example 1 135.50 parts by weight of ethanol was placed in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube.
2. Polyvinylpyrrolidone (average molecular weight 40,000)
6 parts by weight were added and dissolved. Glycidyl methacrylate (60 parts by weight) and 2,2-azobisisobutyronitrile (0.9 parts by weight) were added to this solution, and the mixture was heated to 70 ° C. under a nitrogen atmosphere.
And polymerized for 3 hours. After cooling, a part thereof was extracted, washed with methanol, and the isolated spherical polymer particles had an average particle size of 2.17 μm and a coefficient of variation of 4.8%. The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography.
The maximum value was one of the molecular weights of 120,000 in the molecular weight range of 2,000 to 1,000,000, and the weight average molecular weight was 257,300. The glass transition temperature of the spherical polymer particles was measured by a DSC (SSC5).
80DS: manufactured by SEIKO) at 72 ° C.
Met.

Example 2 67.75 parts by weight of ethanol was placed in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, and polyvinylpyrrolidone (average molecular weight: 40,000) 1.8.
Parts by weight were added and dissolved. To this solution, 30 parts by weight of glycidyl methacrylate and 0.3 part by weight of 2,2-azobisisobutyronitrile were added, and the mixture was heated at 70 ° C. for 3 hours in a nitrogen atmosphere to conduct polymerization for 3 hours. I got

Next, 30 parts by weight of glycidyl methacrylate, 0.3 part by weight of 2,2-azobisisobutyronitrile, 0.3 part by weight of bis (diethylthiocarbamoyl) disulfide and polyvinylpyrrolidone (average molecular weight 40,000) ) 1.8 parts by weight were dissolved in 67.75 parts by weight of ethanol, and this solution was added to a seed particle dispersion medium, followed by heating at 70 ° C under a nitrogen atmosphere to carry out polymerization for 3 hours.
After cooling, the spherical polymer particles isolated by washing with methanol had an average particle size of 2.67 μm and a coefficient of variation of 4.7%.

The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. The molecular weight was found to be 40,000 and 80,000 in the molecular weight range of 2,000 to 1,000,000. There was a maximum.
The glass transition temperature of the spherical polymer particles was determined by DSC.
It was 57 degreeC when it measured with the apparatus (SSC580DS: product made from SEIKO).

Comparative Example 2 135.50 parts by weight of ethanol was placed in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube.
2. Polyvinylpyrrolidone (average molecular weight 40,000)
6 parts by weight were added and dissolved. Glycidyl methacrylate (60 parts by weight) and 2,2-azobisisobutyronitrile (0.6 parts by weight) were added to this solution, and the mixture was heated to 70 ° C. under a nitrogen atmosphere.
And polymerized for 3 hours. After cooling, a part thereof was extracted, washed with methanol, and the isolated spherical polymer particles had an average particle diameter of 2.51 μm and a coefficient of variation of 3.7%. The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography.
The maximum value was one of the molecular weights of 144,000 in the molecular weight range of 2,000 to 1,000,000, and the weight average molecular weight was 279,100.

Example 3 Bis (diethylthiocarbamoyl) disulfide was added to 0.1%.
Polymerization was carried out in the same manner as in Example 2 except that the amount was changed to 6 parts by weight. After cooling, the spherical polymer particles isolated by washing with methanol had an average particle size of 2.47 μm and a coefficient of variation of 5.4%. The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. The maximum values were found to be 30,000 and 100,000 in the molecular weight range of 2,000 to 1,000,000. Were present. Further, the glass transition temperature of the spherical polymer particles is measured by a DSC device (SSC580DS: manufactured by SEIKO).
Was 61 ° C.

Example 4 135.50 parts by weight of ethanol was placed in a reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube.
2. Polyvinylpyrrolidone (average molecular weight 40,000)
6 parts by weight were added and dissolved. To this solution, 30 parts by weight of glycidyl methacrylate and 0.3 part by weight of 2,2-azobisisobutyronitrile were added, and the mixture was heated to 70 ° C. in a nitrogen atmosphere to carry out polymerization for 3 hours, and a seed particle dispersion medium was added. I got

Next, 0.3 parts by weight of 2,2-azobisisobutyronitrile and 0.6 parts by weight of bis (diethylthiocarbamoyl) disulfide were dissolved in 30 parts by weight of glycidyl methacrylate, and this solution was used as seed particles. After the addition to the dispersion medium, the mixture was heated to 70 ° C. in a nitrogen atmosphere to perform polymerization for 3 hours. After cooling, the spherical polymer particles isolated by washing with methanol had an average particle diameter of 1.43 μm and a coefficient of variation of 6.6%. The spherical polymer particles were dissolved in tetrahydrofuran, and the molecular weight in terms of polystyrene was measured by gel permeation chromatography. The maximum values were found to be 32,000 and 110,000 in the molecular weight range of 2,000 to 1,000,000. Were present.

[0036]

According to the present invention, spherical polymer particles having a narrow particle size distribution and a precisely controlled molecular weight distribution can be obtained. Such spherical polymer particles can be used for coating materials, paper coating materials, toners, liquid crystal spacers, cosmetic materials, diagnostic reagent carriers, chromatography fillers, etc., and precisely control the molecular weight distribution. Thus, the melting property and dynamic viscoelasticity can be controlled, so that it can be suitably used particularly for a toner or a liquid crystal spacer.

Claims (12)

[Claims] 1. Spherical polymer particles having two or more maximum molecular weights in the molecular weight range of 2,000 to 1,000,000. 2. The spherical polymer particles according to claim 1, wherein the average particle size is in the range of about 0.1 to about 20 μm. 3. The spherical polymer particles according to claim 1, wherein the coefficient of variation of the average particle size is 10% or less. 4. The spherical polymer according to claim 1, wherein the spherical polymer particles are used as seed particles and the seed particles are enlarged using a polymer having a different maximum molecular weight from the seed particles. Method for producing coalesced particles. 5. The method according to claim 1, wherein the seed particles have a coefficient of variation of the average particle diameter of 10%.
The method for producing spherical polymer particles according to claim 4, which is the following seed particles. 6. The method for producing spherical polymer particles according to claim 4, wherein the polymer having a different maximum molecular weight from the seed particles is compatible with the seed particles. 7. A seed particle obtained by a polymerization reaction of a polymerizable vinyl monomer in a medium in which a polymerizable vinyl monomer is dissolved but a produced polymer is not dissolved. 7. The method for producing spherical polymer particles according to any one of items 1 to 6. 8. The production of spherical polymer particles according to claim 7, wherein the polymerization reaction is a polymerization reaction using a radical initiator in a medium in which the polymerizable vinyl monomer is dissolved but the produced polymer is not dissolved. Method. 9. A polymer having a molecular weight maximum value different from that of the seed particles, and a polymerizable vinyl monomer is dissolved, but a produced polymer is not dissolved by a polymerization reaction of the polymerizable vinyl monomer in a medium. The method for producing spherical polymer particles according to any one of claims 4 to 8, which is a polymer obtained. 10. The production of spherical polymer particles according to claim 9, wherein the polymerization reaction is a polymerization reaction using a radical initiator in a medium in which the polymerizable vinyl monomer is dissolved but the produced polymer is not dissolved. Method. 11. The spherical polymer according to claim 9, wherein the polymerization reaction is a polymerization reaction using a radical initiator and a chain transfer agent in a medium in which the polymerizable vinyl monomer is dissolved but the formed polymer is not dissolved. Method for producing coalesced particles. 12. The method for producing spherical polymer particles according to claim 11, wherein the chain transfer agent is a monosulfide and / or disulfide chain transfer agent. [0001]