JP2001089544A - Polymer fine particles and aqueous dispersion thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily disperse in water without using a conventional surfactant, and to have a very good dispersion stability, a carrier of a diagnostic test agent, cosmetics, a low contraction agent. The present invention provides polymer fine particles and an aqueous dispersion thereof, which can be effectively used for uses such as drug carriers and paints. SOLUTION: The polymer fine particles are composed of an AB type block copolymer comprising an A segment formed from a fluoropolymer portion and a B segment formed from a water-soluble polymer portion. Its average particle size is 10-100
0 nm. The content of the fluoropolymer portion in the A segment is preferably 60% by weight or more, and the content of the water-soluble polymer portion in the B segment is preferably 70% by weight or more. By dispersing the polymer particles in water, an aqueous dispersion is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an AB-type block copolymer, which has good dispersion stability in water,
The present invention relates to a polymer fine particle usable as a carrier of a diagnostic test agent, a cosmetic, a low-contractant, a carrier of a drug, a paint, and the like, and an aqueous dispersion thereof.

[0002]

2. Description of the Related Art Hitherto, polymer fine particles formed from a copolymer containing a fluorine-based monomer have been obtained by an emulsion polymerization method. For example, JP-A-6-287548 discloses that polymer particles comprising a random copolymer can be obtained by emulsion polymerization using a polyoxyalkylene monoalkyl ether as a surfactant.

[0003]

However, in such conventional emulsion polymerization, it is necessary to use a general low molecular weight surfactant, and this surfactant hinders many uses. For example, in the case of forming a coating film, the film properties may be reduced, the skin may be irritated, and the like. For this reason, there is a problem that it is difficult to effectively use polymer fine particles obtained by emulsion polymerization for uses such as a carrier for a diagnostic test agent, a cosmetic, a low-shrinkage agent, a drug carrier, and a paint.

[0004] The present invention has been made by focusing on the problems existing in the prior art as described above. Its purpose is to be able to be easily dispersed in water without using a conventional surfactant, the dispersion stability is very good, carrier of diagnostic test agent, cosmetics, low contraction agent, drug It is an object of the present invention to provide a polymer fine particle and an aqueous dispersion thereof which can be effectively used for applications such as a carrier and a paint.

[0005]

In order to achieve the above object, the polymer fine particles of the first invention are formed from an A segment formed from a fluoropolymer portion and a water-soluble polymer portion. It is composed of an AB-type block copolymer composed of a B segment and has an average particle diameter of 10 to 1000 nm.
It is something that is.

According to a second aspect of the present invention, in the first aspect, the A segment is formed by polymerization of a fluorine monomer alone or a mixture of a fluorine monomer and a non-fluorine monomer. The B segment is formed by polymerization of a water-soluble monomer alone or a mixture of a water-soluble monomer and a water-insoluble monomer.

The polymer fine particles according to a third aspect of the present invention are characterized in that, in the first or second aspect, the content of the fluoropolymer portion in the A segment is 60% by weight or more, and the water-soluble The content of the polymer portion is 70% by weight or more.

A fourth aspect of the invention is an aqueous dispersion obtained by dispersing the fine polymer particles of the first aspect of the invention in water.

[0009]

Embodiments of the present invention will be described below in detail. The polymer fine particles are composed of an AB type block copolymer composed of an A segment formed from a fluoropolymer portion and a B segment formed from a water-soluble polymer portion. Specifically, for example, the above A
The segment is obtained by polymerizing a fluorine monomer alone or a mixture of a fluorine monomer and a non-fluorine monomer, and the B segment is a water-soluble monomer alone or a water-soluble monomer and a water-insoluble monomer. It is obtained by polymerizing a mixture of monomers. The average particle size of the polymer particles is 10 to 1000 nm (nanometer)
It is.

First, the fluorine-based monomer and the water-soluble monomer used are represented by the following general formulas (A) to (G), respectively.
And the following water-soluble monomers. In addition, the non-fluorine-based monomer is a general formula (H) shown below, other polymerizable vinyl monomers and a water-soluble monomer. Further, the water-insoluble monomer is a fluorine-based monomer and other polymerizable vinyl-based monomers represented by the following (A) to (G). (A): RfR ₂ OCOCR ₃ ＣＨCH ₂

[0011]

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[0012]

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[0013]

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[0014]

Embedded image (F): Rf-O-Ar-CH ₂ OCOCR ₃ ＣＨCH
_Two

[0015]

Embedded image (H): R ₄ —OCOCR ₅ ＣＨCH ₂ Rf in the general formulas (A) to (G) is a polyfluoroalkyl group or a polyfluoroalkenyl group having 3 to 21 carbon atoms, and preferably 6 carbon atoms. And 10 to 10 polyfluoroalkyl groups or polyfluoroalkenyl groups. Carbon number 2
Below, the performance of fluorine is hardly exhibited, and when the number of carbon atoms is 22 or more, the chain becomes considerably long and the polymerization conversion rate tends to decrease.

R ₁ is hydrogen or an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms. If it has more than 10 carbon atoms, it will have a long chain and the polymerization conversion tends to decrease.

R ₂ is an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 4 carbon atoms. If it has more than 10 carbon atoms, it will have a long chain and the polymerization conversion tends to decrease.

R ₃ is hydrogen or a methyl group, and Ar is a substituent, for example, an alkyl group having 1 to 10 carbon atoms, an ester group, a ketone group, an amino group, an amide group, an imide group, a nitro group, a hydroxyl group, a carboxyl group. An aryl group which may have an acid group, a thiol group, or an ether group.

N is usually 10 or less, preferably 1 to
4. If n exceeds 10, the effect of fluorine tends to decrease due to the influence of the alkyl chain. Specific examples of the general formula (A) include the following monomers (a-1) to (a-12). _{F (CF 2) 6 (CH} 2) 2 OCOCH = CH 2 (a-1) F (CF 2) 8 (CH 2) 2 OCOCH = CH 2 (a-2) F (CF 2) 10 (CH 2) ₂ OCOCH = CH ₂ (a-3) H (CF ₂ ) ₈ CH ₂ OCOCH = CH ₂ (a-4) (CF ₃ ) ₂ CF (CF ₂ ) ₆ (CH ₂ ) ₂ OCOCH = CH ₂ (a- 5) (CF ₃ ) ₂ CF (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH = CH ₂ (a-6) F (CF ₂ ) ₆ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ (a-7) _{) F (CF 2) 8 (} CH 2) 2 OCOC (CH 3) = CH 2 (a-8) F (CF 2) 10 (CH 2) 2 OCOC (CH 3) = CH 2 (a-9) H _{(CF 2) 8 CH 2 OCOC} (CH 3) = CH 2 (a-10) (CF 3) 2 CF (CF 2) 6 (CH 2) 2 OCOC (CH 3) = CH 2 (a-11) ( CF ₃ ) ₂ CF (CF ₂ ) ₈ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ (a-12) As specific examples of B), the following (b-1) to (b-
7) monomers. _{F (CF 2) 8 SO 2} N (CH 3) (CH 2) 2 OCOCH = CH 2 (b-1) F (CF 2) 8 SO 2 N (CH 3) (CH 2) 4 OCOCH = CH 2 ( _{b-2) F (CF 2} ) 8 SO 2 N (CH 3) (CH 2) 10 OCOCH = CH 2 (b-3) F (CF 2) 3 SO 2 N (C 2 H 5) C (C 2 _{H 5) HCH 2 OCOCH = CH} 2 (b-4) F (CF 2) 8 SO 2 N (CH 3) (CH 2) 2 OCOC (CH 3) = CH 2 (b-5) F (CF 2) _{3 SO 2 N (C 2 H} 5) (CH 2) 2 OCOC (CH 3) = CH 2 (b-6) F (CF 2) 3 SO 2 N (C 3 H 7) (CH 2) 2 OCOC ( CH ₃ ) = CH ₂ (b-7) As specific examples of the general formula (C), the following (c-1) to (c-
And the monomer 4). _{F (CF 2) 2 CON (} C 2 H 5) CH 2 OCOCH = CH 2 (c-1) F (CF 2) 3 CON (CH 3) CH (CH 3) CH 2 OCOCH = CH 2 (c-2 _{) F (CF 2) 8 CON} (C 3 H 7) CH 2 CH 2 OCOC (CH 3) = CH 2 (c-3) F (CF 2) 8 CON (C 2 H 5) CH 2 OCOC (CH 3 ) = CH ₂ (c-4) As specific examples of the general formula (D), the following (d-1) to (d)
-4). _{F (CF 2) 8 CH 2} CH (OH) CH 2 OCOCCH = CH 2 (d-1) (CF 3) 2 CF (CF 2) 2 CH 2 CH (OH) CH 2 OCOCCH = CH 2 (d-2 _{) F (CF 2) 8 CH} 2 CH (OH) CH 2 OCOCC (CH 3) = CH 2 (d-3) (CF 3) 2 CF (CF 2) 2 CH 2 CH (OH) CH 2 OCOCC (CH ₃ ) = CH ₂ (d-4) As specific examples of the general formula (E), the following (e-1) to
and the monomer (e-2).

(CF ₃ ) ₂ CF (CH ₂ ) ₆ CH ₂ CH (OCOCH ₃ ) CH ₂ OCOCH = CH ₂ (e-1) (CF ₃ ) ₂ CF (CH ₂ ) ₆ CH ₂ CH (OCOCH ₃ ) CH ₂ OCOC (CH ₃ ) = CH ₂ (e-2) Further, as specific examples of the general formula (F), the following (f-1) to (f)
-4).

[0021]

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[0022]

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[0023]

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[0024]

Embedded image Specific examples of the general formula (G) include the following monomers (g-1).

[0025]

Embedded image Further, the following monomers may be mentioned as the fluorine-containing monomers other than the general formulas (A) to (G). F (CF ₂ ) ₆ CH ₂ OCH = CH ₂ , F (CF ₂ ) ₈ CH
₂ OCH = CH ₂ , F (CF ₂ ) ₁₀ CH ₂ OCH = C
_{H 2, F (CF 2)} 6 CH 2 OCF = CF 2, F (CF 2)
₈ CH ₂ OCF = CF ₂ , F (CF ₂ ) ₁₀ CH ₂ OCF =
CF ₂ , F (CF ₂ ) ₆ CH = CH ₂ , F (CF ₂ ) ₈ CH
= CH ₂ , F (CF ₂ ) ₁₀ CH = CH ₂ , F (CF ₂ ) ₆ C
F = CF ₂ , F (CF ₂ ) ₈ CF = CF ₂ , F (CF ₂ ) ₁₀
The fluorinated monomer having CF = CF ₂ , CH ₂ ＣＦCF ₂ , CF ₂以上 CF ₂ or more can be used alone or in combination of two or more. In particular, the following compounds are particularly effective as the fluorinated monomer for synthesizing the fluorinated block copolymer from the viewpoint of polymerization conversion. _{F (CF 2) 6 (CH} 2) 2 OCOCH = CH 2 F (CF 2) 8 (CH 2) 2 OCOCH = CH 2 F (CF 2) 6 (CH 2) 2 OCOC (CH 3) = CH 2 F (CF ₂ ) ₈ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ F (CF ₂ ) ₈ SO ₂ N (CH ₃ ) (CH ₂ ) ₂ OCOCH
_{= CH 2 F (CF 2)} 8 SO 2 N (CH 3) (CH 2) 2 OCOC
_{(CH 3) = CH 2 H} (CF 2) 8 CH 2 OCOCH = CH 2 H (CF 2) 8 CH 2 OCOC (CH 3) = CH 2 formula R ₄ is 1 to 22 carbon atoms (H) Represents an alkyl group or a substituted alkyl group, a cycloalkyl group having 3 to 15 carbon atoms or a substituted cycloalkyl group, a phenyl group, or a substituted phenyl group, and R ₅ is a hydrogen atom or a methyl group.

Specific examples of the general formula (H) include the following monomers. Methyl (meth) acrylate, (meth)
Ethyl acrylate, n-propyl (meth) acrylate,
Glycidyl (meth) acrylate, n (meth) acrylate
-Butyl, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, ( Undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate,
Hexadecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate and the like.

Other polymerizable vinyl-based non-fluorinated monomers include the following monomers. Diisopropyl fumarate, dicyclohexyl fumarate, di-t-fumarate
Fumaric acid esters such as -butyl, diisobutyl fumarate and dibenzyl fumarate; aromatic vinyl monomers such as styrene, α-methylstyrene, methoxystyrene, methylstyrene, t-butylstyrene, vinylnaphthalene and vinylpyridine; vinyl formate Carboxylic acid vinyl esters such as vinyl acetate, vinyl propionate and vinyl stearate, (meth) acrylic acid esters of alcohols having a tertiary amino group such as (meth) acrylic acid N, N-dimethylamino ester, ( Tetrahydropyranyl (meth) acrylate, tetrahydrofuranyl (meth) acrylate, methoxymethyl (meth) acrylate, (meth)
Ethoxymethyl acrylate, methoxyethoxymethyl (meth) acrylate, benzyloxymethyl (meth) acrylate.

The following monomers are mentioned as the water-soluble monomers. (Meth) acrylic acid, (meth) acrylamide, (meth) acrylamide N, N-dimethyl, (meth) acrylamide N, N-diethyl, (meth) acrylamide propyl sulfonate, maleic acid, Itaconic acid, itaconic acid diamide, fumaric acid, 2-hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, mono ( (Meth) polyethylene glycol acrylate, sodium styrene sulfonate.

Among the above monomers, the following monomers are preferred from the viewpoint of ensuring a high polymerization conversion rate or solubility in a solvent. Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) in compounds (A), (G), and compound (H) ) T-butyl acrylate, glycidyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate , Benzyl (meth) acrylate.

The other polymerizable vinyl non-fluorinated monomers include diisopropyl fumarate, dicyclohexyl fumarate, di-t-butyl fumarate, diisobutyl fumarate, dibenzyl fumarate, styrene, α-
Methyl styrene, methoxy styrene, methyl styrene,
t-butylstyrene, vinylnaphthalene, vinylpyridine, vinyl acetate, N, N-dimethylamino (meth) acrylate, tetrahydropyranyl (meth) acrylate, tetrahydrofuranyl (meth) acrylate, methoxy (meth) acrylate Methyl, ethoxymethyl (meth) acrylate, methoxyethoxymethyl (meth) acrylate, benzyloxymethyl (meth) acrylate.

Further, as the water-soluble monomers, (meth) acrylic acid, (meth) acrylamide, (meth) acrylamide N, N-dimethyl, (meth) acrylamide propyl sulfonate, itaconic acid, Itaconic acid diamide, 2-hydroxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, mono (meth) acrylate
Tetraethylene glycol acrylate, polyethylene glycol mono (meth) acrylate, sodium styrene sulfonate.

Among the above monomers, the following monomers are more preferable. The compounds described above (a-1 to 3,
5 to 9, 11, 12), compound (g-1), methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acryl N-butyl acid, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
Dodecyl acrylate, stearyl (meth) acrylate,
Cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diisopropyl fumarate, dicyclohexyl fumarate, di-t-butyl fumarate, styrene, α-methylstyrene, methoxystyrene, methylstyrene, t
-Butylstyrene, vinylpyridine, vinyl acetate, N, N-dimethylamino (meth) acrylate, tetrahydropyranyl (meth) acrylate, tetrahydrofuranyl (meth) acrylate, methoxymethyl (meth) acrylate, ) Ethoxymethyl acrylate, benzyloxymethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylamide, (meth) acrylamide N, N-dimethyl, propyl (meth) acrylate amide sulfonate, Itaconic acid, (meth) acrylic acid 2
-Hydroxyethyl, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, sodium styrenesulfonate.

The A segment in the AB type block copolymer is formed of one or more of a fluorine monomer alone or a fluorine monomer and a non-fluorine monomer. Among them, the fluorine-based polymer portion in the AB block copolymer is preferably at least 60% by weight,
More preferably, it is at least 80% by weight. When the fluoropolymer portion is less than 60% by weight, the AB
Since the block copolymer is dissolved in water and does not agglomerate, polymer fine particles cannot be reliably formed.

On the other hand, the B segment is formed of one or more of a water-soluble monomer alone or a water-soluble monomer and a water-insoluble monomer. The content of the water-soluble polymer in the AB block copolymer is preferably 70% by weight or more, and more preferably 90% by weight or more. When the content of the water-soluble polymer is less than 70% by weight, A
When the B-type block copolymer is dispersed in water, it coagulates and precipitates without dispersing, or even when dispersed, the appearance of the dispersion becomes white and the transparency tends to be lost, and precipitation tends to occur with time. .

Next, the ratio of the A segment to the B segment of the AB type block copolymer is preferably 20% by weight.
/ 80 to 95/5, more preferably 30/70
９０90/10. If the A segment is less than 20/80, it is completely dissolved in water, and it is difficult to form polymer fine particles. On the other hand, when the ratio exceeds 95/5, the polymer fine particles can be stably dispersed in water, and are likely to precipitate.

The number average molecular weight of the AB type block copolymer is preferably 5,000 to 1,000,000, more preferably 10,000 to 300,000, and
000 to 100,000 is particularly preferred. When the number average molecular weight is less than 5000, the production efficiency of the AB type block copolymer decreases, and as a result, the production efficiency of the polymer fine particles also decreases. On the other hand, if it exceeds 1,000,000, it becomes difficult to produce the AB block copolymer itself.

Next, a method for producing the AB type block copolymer will be described. This AB type block copolymer can be synthesized according to an anionic polymerization method or a method using a polymeric peroxide.

First, the case of the anionic polymerization method will be described. As the polymerization solvent used, benzene, toluene, ethylbenzenepropylbenzene, butylbenzene, xylene, cyclopentane, cyclohexane, hexane, heptane, octane, nonane, decane, undecane, dodecane, diethyl ether, dipropyl ether, dibutyl ether, dipentyl Solvents having no active hydrogen such as ether, dihexyl ether, tetrahydrofuran, dioxane and the like can be mentioned.

From the viewpoint of facilitating the handling of the solvent, preferably, benzene, toluene, ethylbenzene, propylbenzene, butylbenzene, xylene, cyclopentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, Dibutyl ether,
Dipentyl ether, dihexyl ether, tetrahydrofuran and dioxane. These solvents can be used alone or as a mixed solvent.

Examples of the polymerization initiator include alkyl metals such as ethyl lithium, propyl lithium, n-butyl lithium, s-butyl lithium, and t-butyl lithium, methyl magnesium chloride, ethyl magnesium chloride, and the like.
Propyl magnesium chloride, butyl magnesium chloride, phenyl magnesium chloride, 4-methylphenyl magnesium chloride, methyl magnesium bromide, ethyl magnesium bromide, propyl magnesium bromide, butyl magnesium bromide, phenyl magnesium bromide, 4-methylphenyl magnesium bromide, etc. Grignard reagent,
Lithium, sodium, alkali metals such as potassium, lithium methoxide, lithium ethoxide, lithium propoxide, lithium butoxide, sodium methoxide, sodium ethoxide, sodium propoxide,
Metal alcoholates such as sodium butoxide, potassium methoxide, potassium ethoxide, potassium propoxide, potassium butoxide and the like can be mentioned.

From the viewpoint of maintaining good handling of reagents, n-butyllithium, s-butyllithium, t-butyllithium, ethylmagnesium chloride, propylmagnesium chloride, butylmagnesium chloride, phenylmagnesium are preferable. Chloride, 4-methylphenylmagnesium chloride, ethyl magnesium bromide, propyl magnesium bromide, butyl magnesium bromide, phenyl magnesium bromide, 4-methylphenyl magnesium bromide, lithium, sodium, potassium, lithium methoxide, lithium ethoxide, lithium Propoxide, lithium butoxide, sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium Mumetokishido, potassium ethoxide, potassium propoxide and potassium butoxide.

From the viewpoint of suppressing the production cost and obtaining a high anionic polymerization efficiency, more preferably, n
-Butyl lithium, s-butyl lithium, t-butyl lithium, ethyl magnesium bromide, propyl magnesium bromide, butyl magnesium bromide,
Phenylmagnesium bromide, 4-methylphenylmagnesium bromide, sodium, lithium ethoxide, lithium propoxide, lithium butoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium ethoxide, potassium propoxide and potassium butoxide. .

Since the molecular weight of the obtained polymer can be regulated by the amount of these polymerization initiators used, the amount of the polymerization initiator to be used is determined according to the molecular weight of the target polymer.

As the polymerization initiator, diphenylethylene may be previously reacted with the above-mentioned polymerization initiator, and the reaction product may be used as the polymerization initiator. In this case, the amount of diphenylethylene used is ideally equimolar to the polymerization initiator, but the actual amount used is 0.5% of the polymerization initiator.
An amount corresponding to ３3 molar equivalents, preferably 0.8-1.5 molar equivalents is desirable. By using this diphenylethylene, the efficiency of anionic polymerization can be increased, and the efficiency of blocking can be improved.

Further, as one of the additives, as a molecular weight distribution regulator, lithium chloride, lithium bromide, lithium ethoxide, lithium (2-methoxyethoxide), lithium (2-ethoxyethoxide), lithium (2-ethoxyethoxide) Propoxy ethoxide), lithium (2-butoxy ethoxide), lithium (2- (2-methoxy ethoxy) ethoxide), sodium chloride, sodium bromide, sodium ethoxide, sodium (2
-Methoxy ethoxide), sodium (2-ethoxy ethoxide), sodium (2-propoxy ethoxide), sodium (2-butoxy ethoxide), sodium (2- (2-methoxy ethoxy) ethoxide), potassium chloride, potassium Bromide, potassium ethoxide, potassium (2-methoxy ethoxide), potassium (2-ethoxy ethoxide), potassium (2-propoxy ethoxide), potassium (2-butoxy ethoxide)
And potassium (2- (2-methoxyethoxy) ethoxide).

Further, from the viewpoint of further narrowing the molecular weight distribution, preferably, lithium chloride, lithium bromide, lithium (2-methoxyethoxide), lithium (2-ethoxyethoxide), lithium (2- (2- (2-ethoxyethoxide)) are used.
(Methoxyethoxy) ethoxide), sodium bromide, sodium ethoxide, sodium (2-methoxyethoxide), sodium (2-ethoxyethoxide), sodium (2- (2-methoxyethoxy) ethoxide), potassium bromide, potassium ethoxide , Potassium (2-methoxy ethoxide), potassium (2-ethoxy ethoxide) and potassium (2- (2-methoxy ethoxy) ethoxide).

From the viewpoint of further narrowing the molecular weight distribution and not lowering the polymerization rate of anionic polymerization, lithium chloride, lithium bromide, lithium (2-methoxyethoxide) and lithium (2-ethoxyethoxide) are more preferred. ), Lithium (2- (2-methoxyethoxy) ethoxide), sodium (2-methoxy ethoxide), sodium (2-ethoxy ethoxide), sodium (2- (2-methoxy ethoxy) ethoxide), potassium (2- Methoxy ethoxide), potassium (2-ethoxy ethoxide) and potassium (2- (2-
Methoxyethoxy) ethoxide).

These additives can be used alone or as a mixture. The amount of these additives used is preferably 0.5 to 50 molar equivalents of the polymerization initiator,
1.0-20 molar equivalents are more preferred.

Next, a specific polymerization operation using the above reagents will be described. It is preferable to use all reagents that have been subjected to a dehydration operation. By performing the dehydration operation, anionic polymerization can be reliably performed, and polymer fine particles composed of a desired block copolymer can be obtained.

First, the inside of the container containing the additive (and diphenylethylene in some cases) is replaced with nitrogen while sufficiently dehumidifying. There, a polymerization solvent is introduced, and a predetermined polymerization temperature is set. This polymerization temperature is preferably -120 to 50 ° C, more preferably -10 ° C.
0-30 ° C.

Subsequently, a water-soluble monomer or a monomer mixture of a water-soluble monomer and a water-insoluble monomer for forming the B segment is preferably used for 1 second to 10 minutes, more preferably 5 seconds. It is dropped over a period of from 2 to 2 minutes, and then preferably from 5 minutes to 10 minutes.
Hold for a time, more preferably 10 minutes to 5 hours.

Next, a fluorine-based monomer or a monomer mixture of a fluorine-based monomer and a non-fluorine-based monomer for forming the A segment is preferably used for 1 to 10 minutes, more preferably 5 seconds. The solution is added dropwise over a period of 2 to 2 minutes, and then preferably maintained for 5 minutes to 24 hours, more preferably 10 minutes to 10 hours. After completion of the reaction, a compound having an active proton such as methanol (which may contain an acid such as hydrochloric acid in some cases) is added to inactivate the anionic species.

By the above operation, an AB type block copolymer can be obtained. However, in the case of anionic polymerization, a monomer having active hydrogen cannot be polymerized. Therefore,
To obtain an AB type block copolymer containing a desired water-soluble polymer portion, t-butyl (meth) acrylate, di-t-butyl fumarate, and (meth) acrylic acid are used instead of the water-soluble monomer. Polymerization using tetrahydropyranyl, tetrahydrofuranyl (meth) acrylate, methoxymethyl (meth) acrylate, ethoxymethyl (meth) acrylate, methoxyethoxymethyl (meth) acrylate or benzyloxymethyl (meth) acrylate The AB type block copolymer obtained is thermally decomposed into a carboxylic acid group to obtain an AB type block copolymer containing a water-soluble polymer portion.

In this thermal decomposition, it is also useful to add an acid. In this case, the thermal decomposition proceeds more rapidly at a lower temperature due to the catalytic effect of the acid. The acids used here include sulfuric acid, sulfurous acid, hydrochloric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, metaphosphoric acid, organic sulfonic acid compounds, organic phosphoric acid compounds, carboxylic acid compounds, recently chemically amplified resists, etc. And the like.

Examples of the above organic sulfonic acid compounds include the following compounds. Methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, hexanesulfonic acid, heptanesulfonic acid, octanesulfonic acid, nonanesulfonic acid, sulfoacetic acid, 3-sulfopropylacrylic acid, 3-sulfopropyl Methacrylic acid, 2-acrylamido-2-methyl
-1-propanesulfonic acid, p-toluenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-sulfobenzoic acid, xylenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid and dinonylnaphthalenedisulfonic acid.

Examples of the organic phosphoric acid compound include the following compounds. Phenylphosphinic acid, bis (4
-Methoxyphenyl) phosphinic acid, diphenylphosphinic acid, dimethylphosphinic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, t-butylphosphonic acid, methylenediphosphonic acid, 2-chloroethylphosphonic acid, phosphonoacetic acid, 2- Carboxyethylphosphonic acid,
Ethyl methylphosphonate, phenylphosphonic acid, diphenylphosphonic acid, dibenzylphosphonic acid and 1-naphthylphosphonic acid.

Examples of the carboxylic acid compound include the following compounds. Chloroacetic acid, dichloroacetic acid, trichloroacetic acid, fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, bromoacetic acid, dibromoacetic acid and tribromoacetic acid.

The acids mentioned above can be used in free form,
It may be used by blocking with amines. The amines herein include, for example, primary, secondary and tertiary alkylamines having 20 or less carbon atoms, primary amines having 20 or less carbon atoms,
Secondary and tertiary hydroxyalkylamines, primary, secondary and tertiary cycloaliphatic amines having 20 or less carbon atoms,
Heterocyclic amines and the like are mentioned, and specifically, the following compounds are mentioned.

Ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine,
Tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, isopropylamine,
s-butylamine, t-butylamine, ethylenediamine,
1,3-diaminopropane, 1,2-diaminopropane, 1,4-diaminobutane, 2,2-dimethyl-1,
3-propanediamine, 1,6-hexanediamine,
1,7-diaminoheptane, 1,8-diaminooctane, 2,5-dimethyl-2,5-hexanediamine,
1,9-diaminononane, 1,10-diaminodecane,
1,12-diaminododecane, ethylmethylamine, diethylamine, methylpropylamine, methylisopropylamine, dipropylamine, diisopropylamine, methylbutylamine, ethylbutylamine, dibutylamine, dipentylamine, methylhexylamine,
Dihexylamine, dioctylamine, bis (2-ethylhexyl) amine, didecylamine, methyloctadecylamine, dimethylethylamine, diethylmethylamine, triethylamine, tripropylamine, dimethylbutylamine, methyldibutylamine, tributylamine, diethylethylenediamine, tetramethylethylenediamine, Tetramethyldiaminomethane, tetramethyl-1,3-propanediamine, tetraethyl-1,3
-Propanediamine, cyclopentylamine, cyclohexylamine, dicyclohexylamine, dimethylcyclohexylamine, diethylcyclohexylamine, diaminocyclohexane, ethanolamine, propanolamine, diethanolamine, triethanolamine, triisopropanolamine, pyrrolidone, methylpyrrolidone, ethylpyrrolidone, piperidine, Methylpiperidine, ethylpiperidine, dimethylstearylamine, morpholine, methylmorpholine, ethylmorpholine, aniline, methylaniline, dimethylaniline, ethylaniline, diethylaniline, diphenylamine,
Phenylpiperidine, triphenylamine, 2-anilinoethanol, indoline, phenylenediamine, pyridine, dimethylaminopyridine and diethylaminopyridine.

Examples of the acid generator used in the chemically amplified resist include compounds such as onium salts, halogen-containing compounds, and nitrobenzyl esters. An acid generator used for a chemically amplified resist or the like is, for example, a compound capable of generating a proton upon irradiation with light.
Therefore, in the case of using this acid generator also in the present invention, if an acid is generated by light irradiation, it can be considered in the same manner as the above-mentioned ordinary acid.

The acid used is preferably from 0.001 to 30% by weight, more preferably from 0.01 to 20% by weight, particularly preferably from 0.1 to 30% by weight, based on the AB type block copolymer.
15% by weight.

The thermal decomposition can be performed in a solvent in which the AB block copolymer before decomposition is soluble or in the absence of a solvent. Further, the decomposition temperature is 0 to 300 ° C., preferably 30 to 250 ° C. in view of a practical temperature, and more preferably 50 in consideration of the heat stability (oxidation, decomposition, etc.) of the AB type block copolymer itself. ~ 200 ° C. on the other hand,
Decomposition time is 1 minute to 24 hours, 2 minutes to 12 hours in consideration of practical decomposition time, and sufficient thermal decomposition and heat stability of AB type block copolymer itself (oxidation, decomposition, etc.)
In consideration of the above, it is more preferably 30 minutes to 5 hours.

As described above, the desired AB type block copolymer can be obtained by the anionic polymerization method. Next, the case of the method using polymeric peroxide will be described. This polymerization method can be performed by a known production process (for example, Japanese Patent Publication No. 5-41668 or Japanese Patent Publication No. 5-599).
No. 42). A specific method will be described below.

The polymeric peroxide used at the time of producing the above block copolymer is a compound having two or more peroxy bonds in one molecule. As the polymeric peroxide, one or more of various polymeric peroxides described in JP-B-5-59942 can be used.

For example, those represented by the following general formulas (1) and (2) can be used.

[0066]

Embedded image

[0067]

Embedded image Here, m is an integer of 2 to 20.

The block copolymer can be easily obtained by the usual bulk polymerization, suspension polymerization, solution polymerization, or emulsion polymerization using the above-mentioned polymeric peroxide. For example, in the case of a solution polymerization method, a B segment having a water-soluble polymer portion formed from a water-soluble monomer or a water-soluble monomer and a water-insoluble monomer in the first step as a block copolymer, Taking the case of forming an A segment having a fluorine-based polymer portion formed from a fluorine-based monomer or a fluorine-based monomer and a non-fluorine-based monomer in the second step as an example, the following description is given. can do.

That is, first, a peroxide-containing polymer in which a peroxide bond is introduced into a chain is obtained by using a polymeric peroxide as a polymerization initiator and performing the polymerization in the first step in a solution. Next, in the second step, when the monomer of the second step is polymerized in the production solution of the first step, the monomer is cleaved at the peroxide bond in the peroxide bond-containing polymer, and the block copolymer is efficiently produced. Is obtained.

In the above two-stage polymerization,
The monomers of the first step may be used in the second step and the monomers of the second step may be used in the first step. The amount of the polymeric peroxide used in the first step in the production of the block copolymer is usually 0.5 to 20 parts by weight based on 100 parts by weight of the monomer, and the polymerization temperature at that time is 60 to 130 ° C. The polymerization time is about 2 to 10 hours.

The polymerization temperature in the second step is usually 60
To 140 ° C., and the polymerization time is about 3 to 15 hours. The polymerization solvent of the fluorinated block copolymer obtained as described above is not particularly limited as long as it can dissolve or disperse the block copolymer, and examples thereof include the following solvents.

Water, methyl alcohol, ethyl alcohol, propyl alcohol, 2-propyl alcohol,
-Butyl alcohol, 2-butyl alcohol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, cyclopentanol, 2-hexanol, 3-
Hexanol, cyclohexanol, methyl cellosolve, ethyl cellosolve, acetone, 2-butanone, 3-
Methyl-2-butanone, 2-pentanone, 3-pentanone, 2-methyl-3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2,4-dimethyl-3-pentanone, 4, 4-dimethyl-2-pentanone, 2-hexanone, 3-hexanone, cyclopentanone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-hexanone,
5-methyl-2-hexanone, 5-methyl-3-hexanone, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, trimethyl methyl acetate, isobutyl acetate, s-butyl acetate, pentyl acetate, isoamyl acetate, propion Methyl acetate, ethyl propionate, propyl propionate, butyl propionate, isobutyl propionate, t-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, 2 −
Methyl-methyl butyrate, methyl caproate, benzene, toluene, ethylbenzene, xylene, phenol, cyclohexane, hexane, heptane, octane, nonane,
Decane, undecane, dodecane, formamide, acetamide, dimethylformamide, dimethylacetamide, acetonitrile, tetrahydrofuran, 1,1,2
-Trifluoro-1,2,2-trichloroethane, tetrachlorodifluoroethane, methylchloroform, hexafluoroisopropanol, (meth) paraxylenehexafluoride, perfluorohexane and perfluoroheptane.

These solvents may be used alone or as a mixed solvent when not used alone. Among these, the following solvents are preferred from the viewpoint of cost and environmental stability.

Water, methyl alcohol, ethyl alcohol, propyl alcohol, 2-propyl alcohol, 1
-Butyl alcohol, 2-butyl alcohol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, cyclopentanol, methyl cellosolve, ethyl cellosolve, Acetone, 2-butanone, 3-methyl-
2-butanone, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isoamyl acetate, methyl butyrate, ethyl butyrate, propyl butyrate, toluene, ethylbenzene,
Xylene, cyclohexane, hexane, heptane, decane, dodecane, formamide, acetamide, dimethylformamide, dimethylacetamide and acetonitrile.

These solvents may be used alone or as a mixed solvent if they are not used alone. Also,
As in the case of anionic polymerization, it is also possible to thermally decompose the AB block copolymer later to obtain the target AB block copolymer. In this case, the monomers suitable for thermal decomposition, the conditions for thermal decomposition, and the like are the same as those in the case of anionic polymerization.

The concentration of the AB type block copolymer thus obtained in water is preferably 0.000
01-70% by weight, more preferably 0.0001-5
0% by weight, particularly preferably 0.001 to 35% by weight. If the concentration is less than 0.00001% by weight, fine particles due to association of the AB type block copolymer will be insufficient, and if it exceeds 70% by weight, the viscosity of the dispersion will increase and the production of the dispersion will be extremely difficult. Extreme difficulty.

The polymer fine particles thus obtained are:
In the appearance of the dispersion liquid in which the polymer particles are dispersed,
It is necessary not to cause precipitation of the polymer fine particles.
Therefore, the average particle size is 10 to 1000 nm, preferably 10 to 500 nm, and more preferably 15 to 350 nm.
nm. When the average particle size is smaller than 10 nm, it is difficult to measure the average particle size, and it is impossible to determine the difference between dispersion and dissolution. Also, when it exceeds 1000 nm,
In the dispersion in which the polymer particles are dispersed, precipitation of the polymer particles occurs, so that the stability as the dispersion cannot be ensured.

The average particle size of the fine polymer particles can be changed by changing the molecular weight of the A segment of the AB type block copolymer, the weight ratio of the A segment to the B segment, and the like. That is, since the A segment formed from a fluorine-based monomer or the like has a cohesive force,
Polymer particles are formed by the aggregation. Therefore, as the molecular weight of the A segment is larger, the cohesive force is stronger, and a larger number of large molecules are collected. Similarly, as the weight ratio of the A segment to the B segment increases, the size of the polymer fine particles increases.

The effects exerted by the above embodiment will be described below. -The above polymer fine particles are composed of a high molecular weight block copolymer composed of an A segment formed from a fluoropolymer portion and a B segment formed from a water-soluble polymer portion. The A segment is a hydrophobic portion, and the B segment is a water-soluble portion, and the block copolymer itself functions as a surfactant. Therefore, the polymer particles are dispersed in water in a stable state,
Such a stable dispersion state is maintained for a long time.

Further, since the polymer fine particles can be obtained without using a conventional surfactant, there is no decrease in film physical properties when a coating film is formed using the polymer fine particles, and irritation to the skin is prevented. Is also suppressed.

The polymer fine particles have the above-mentioned properties, and also have chemical resistance, heat resistance, water repellency, oil repellency, weather resistance, and electrical insulation properties based on the fluoropolymer portion of the A segment. Functions such as low friction and non-adhesiveness are exhibited. Therefore, the polymer microparticles can be effectively used for uses such as carriers for diagnostic test agents, cosmetics, low-contractants, drug carriers, and paints.

The content of the fluoropolymer portion in the A segment of the AB type block copolymer is 60% by weight.
By setting the content as described above and the content of the water-soluble polymer portion in the B segment to 70% by weight or more, the above-described effect of the polymer fine particles can be surely exerted.

The dispersion in which the above-mentioned polymer fine particles are dispersed in water is maintained in a good dispersion state, so that the polymer fine particles can be easily obtained and can be effectively applied to the above-mentioned respective applications. .

[0084]

EXAMPLES Hereinafter, the above embodiments will be described more specifically with reference to examples, but the present invention is not limited by these examples. (Example 1) 100 ml of tetrahydrofuran was placed in a reactor,
0.7 g of lithium chloride, 0.03 g of diphenylethylene
Was introduced and replaced with nitrogen, and then cooled to −78 ° C., and thereto was added 0.2 ml of a hexane solution of butyllithium, followed by sufficient stirring. Next, 4.5 g of t-butyl methacrylate was introduced and stirred at -78 ° C for 30 minutes, and C 、 C (CH ₃ ) was added thereto.
COO (CH ₂ ) ₂ (CF ₂ ) ₇ CF ₃ (hereinafter referred to as FMA
4.5 g) and stirred at -78 ° C for 3 hours.

Then, about 2 m of a 1N methanolic hydrochloric acid solution was prepared.
1 was added to inactivate the anionic species. This polymerization solution was dropped into 2,000 ml of methanol while stirring to precipitate a block copolymer, and the precipitate was dried to obtain a powder.

1 g of the obtained block copolymer was dissolved in 10 ml of dioxane, and 1 ml of concentrated hydrochloric acid was added thereto.
For 5 hours, and the methacrylic acid t of the block copolymer
-The butyl moiety was changed to methacrylic acid. The reaction solution was added dropwise to 200 ml of ethyl acetate with stirring to obtain a target AB-type block copolymer as a powder. In this AB type block copolymer, the fluoropolymer portion in the A segment was 100% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

0.1 g of this AB type block copolymer was added to 100 ml of water, and sufficiently stirred and dispersed. The average particle size of the polymer fine particles comprising the AB type block copolymer in this dispersion was measured and found to be 55 nm.

The appearance of this dispersion was pale blue and almost transparent, and when left standing at room temperature for 1 week, it was very stable with no precipitate. Example 2 t-butyl methacrylate of Example 1 4.5
g was changed to 3.5 g of t-butyl methacrylate and 1.0 g of methyl methacrylate, 4.5 g of FMA was changed to 3.0 g of FMA and 1.5 g of ethyl methacrylate. Polymer fine particles having a diameter of 85 nm were obtained. A in this AB type block copolymer
66.7% by weight of a fluoropolymer portion in the segment,
The water-soluble polymer portion in the B segment was 71.1% by weight.

The appearance of this polymer dispersion was pale blue and almost transparent, and when left at room temperature for 1 week, it was very stable without precipitate. (Example 3) 4.5 g of FMA of Example 1 was added to FMA2.5.
Example 1 was repeated except that g was used. as a result,
Polymer fine particles having an average particle diameter of 35 nm were obtained. In the AB type block copolymer, the fluoropolymer portion in the A segment was 100% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

The appearance of this polymer dispersion was pale blue and almost transparent, and when left at room temperature for 1 week, it was very stable with no precipitate. Example 4 t-butyl methacrylate of Example 1
Example 1 was followed except that 5 g was replaced by 3.5 g and FMA 4.5 g by FMA 6.5 g. As a result, polymer fine particles having an average particle diameter of 180 nm were obtained. In the AB type block copolymer, the fluorine-based polymer portion in the A segment was 100% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

The appearance of the polymer dispersion was pale blue-white and almost transparent, and when left at room temperature for one week, it was very stable with no precipitate. (Example 5) 0.7 g of lithium chloride of Example 1 was deleted, 0.03 g of diphenylethylene was added to 0.1 g of diphenylethylene, and 0.2% of a hexane solution of butyllithium was added.
Example 1 was followed except that the ml was changed to 0.6 ml. As a result, polymer fine particles having an average particle diameter of 35 nm were obtained. In the AB type block copolymer, the fluorine-based polymer portion in the A segment was 100% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

The appearance of this polymer dispersion was pale blue and almost transparent, and when left at room temperature for 1 week, it was very stable without a precipitate. (Example 6) 0.03 of diphenylethylene of Example 1
g in 0.01 g of diphenylethylene, 0.2 ml of a hexane solution of butyllithium and 0.05 ml of a hexane solution of butyllithium in the same manner as in Example 1. As a result, polymer fine particles having an average particle diameter of 155 nm were obtained. In the AB type block copolymer, the fluoropolymer portion in the A segment is 100% by weight,
The water-soluble polymer portion in the B segment was 100% by weight.

The appearance of this polymer dispersion was pale blue-white and almost transparent, and when left at room temperature for 1 week, it was very stable without precipitate. (Example 7) 5 equipped with a thermometer, a stirrer and a reflux condenser
60.0 g of isopropyl alcohol was charged into a 00 ml four-necked flask, and 70 ° C. while blowing nitrogen gas.
Then, both of the mixed solutions in which 5.0 g of a polymeric peroxide represented by the following chemical formula (3) was dispersed in 50.0 g of acrylic acid and 50.0 g of isopropyl alcohol were simultaneously charged over 2 hours. The polymerization reaction was further performed for 2.5 hours to obtain a solution having a peroxide bond-containing polymer.

[0094]

Embedded image Subsequently, the solution after the polymerization was heated to 70 ° C., and while blowing nitrogen gas, isopropyl alcohol 90.0% was added.
g CH ₂ = CHCOO (CH ₂ ) ₂ (CF ₂ ) ₇ CF ₃
A mixed solution of 50.0 g (hereinafter, abbreviated as FA) was charged over 40 minutes, and a polymerization reaction was further performed for 1.5 hours.
After raising the temperature to 0 ° C., the polymerization reaction is further performed for 3 hours, whereby AB
A block copolymer dispersion was obtained. In the AB type block copolymer, the fluorine-based polymer portion in the A segment was 100% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

The obtained AB type block copolymer was dispersed in water according to Example 1, and the average particle size of the polymer fine particles comprising the AB type block copolymer in this dispersion was measured to be 55 nm. Was. (Example 8) 5 equipped with a thermometer, a stirrer and a reflux condenser
In a 00 ml four-necked flask, add methyl ethyl ketone 6
0.0 g, and heated to 70 ° C. while blowing in nitrogen gas, and 50.0 g of t-butyl methacrylate was added thereto.
, 50.0 g of methyl ethyl ketone, and 7.0 g of the polymeric peroxide represented by the chemical formula (3) were simultaneously dispersed over 2 hours, and the polymerization reaction was further performed for 4 hours to obtain a peroxide bond. A solution containing the polymer was obtained.

Subsequently, the solution after the polymerization was heated to 70 ° C., and a mixed solution of 90.0 g of methyl ethyl ketone, 35.0 g of FA and 15.0 g of t-butyl methacrylate was charged over 40 minutes while blowing nitrogen gas. Further 1.
The polymerization reaction was carried out for 5 hours, followed by heating to 80 ° C.
The block copolymer dispersion was obtained by performing the polymerization reaction for a period of time.

From this polymerization solution, the block copolymer was taken out as a powder according to Example 1 and further subjected to a thermal decomposition reaction to obtain a target AB-type block copolymer. This A
In the B-type block copolymer, the fluoropolymer portion in the A segment was 76.8% by weight, and the water-soluble polymer portion in the B segment was 100% by weight.

The obtained AB type block copolymer 0.00
5 g was added to 100 ml of water, and the mixture was sufficiently stirred and dispersed. The average particle size of the polymer fine particles comprising the AB block copolymer in this dispersion was measured and found to be 35 nm.

The appearance of this dispersion was pale blue and almost transparent, and when left standing at room temperature for one week, it was very stable with no precipitate. (Comparative Example 1) In Example 1, an attempt was made to disperse the intermediate block copolymer before thermal decomposition in water in the same manner as in Example 1, but it was only precipitated but could not be dispersed. That is, since this block copolymer did not have a water-soluble polymer portion, it could not be dispersed in water. (Comparative Example 2) When the particle size was measured using the polymer in which the polymerization of FMA was omitted in Example 1, no particles were confirmed and it was found that all were dissolved. That is, since this polymer did not become a block copolymer having a fluoropolymer portion, no fine particles were formed.

The technical ideas grasped from the above embodiment will be described below. The AB-type block copolymer is a fluorine-based monomer alone or a mixture of a fluorine-based monomer and a non-fluorine-based monomer, and a monomer alone or a monomer that forms a water-soluble monomer portion by thermal decomposition. A polymer obtained by polymerizing a mixture of a monomer forming a water-soluble monomer portion by decomposition and a monomer forming a water-insoluble monomer portion by anionic polymerization, and then thermally decomposing the mixture. 2. The polymer fine particles according to 1.

In the case of such a constitution, the target polymer fine particles can be obtained efficiently. The AB-type block copolymer is a polymerizable polymerization initiator, a fluorine-based monomer alone or a mixture of a fluorine-based monomer and a non-fluorine-based monomer or a water-soluble monomer alone or a water-soluble monomer After polymerizing a mixture of a monomer and a water-insoluble monomer, a water-soluble monomer alone, a mixture of a water-soluble monomer and a water-insoluble monomer, or a fluorine-based monomer alone in the polymerization solution. The polymer fine particles according to claim 2, which are formed by a method of polymerizing a mixture of a fluorine monomer and a non-fluorine monomer.

In the case of such a constitution, the desired polymer fine particles can be efficiently obtained by a simple operation. The polymer fine particles according to claim 1, wherein the AB type block copolymer is obtained by performing anionic polymerization using a reaction product of diphenylethylene with a polymerization initiator.

With this configuration, the efficiency of anionic polymerization can be increased, and the efficiency of blocking can be improved.

[0104]

As described above, the present invention has the following advantages. According to the polymer microparticles of the first and second inventions, they can be easily dispersed in water in a stable state without using a conventional surfactant. Therefore, the polymer microparticles can be effectively used for a carrier of a diagnostic test agent, a cosmetic, a low contraction agent, a drug carrier, a paint and the like.

According to the polymer fine particles of the third invention, the first
Alternatively, the effects of the second invention can be more reliably exerted. According to the aqueous dispersion of the fourth invention, the polymer fine particles of the invention according to any one of the first to third aspects are easily dispersed in water without using a conventional surfactant. To obtain a stable aqueous dispersion.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F070 AA23 AA30 AA36 AB08 AC17 AC20 AC24 AC40 AC46 BA02 DA46 DA54 4J015 BA01 BA06 BA11 DA02 DA03 4J026 HA11 HA12 HA19 HA23 HA26 HA32 HB11 HB12 HB19 HB23 HB26 HB32 HB43 HDB12 HD48 HE01

Claims (4)

[Claims] 1. An AB type block copolymer comprising an A segment formed from a fluoropolymer portion and a B segment formed from a water-soluble polymer portion,
Polymer fine particles having an average particle diameter of 10 to 1000 nm. 2. The A segment is formed by polymerization of a fluorine monomer alone or a mixture of a fluorine monomer and a non-fluorine monomer, and the B segment is a water-soluble monomer alone or a water-soluble monomer. The polymer fine particles according to claim 1, wherein the polymer fine particles are formed by polymerization from a mixture of a solid and a water-insoluble monomer. 3. The content of the fluoropolymer portion in the A segment is 60% by weight or more, and the content of the water-soluble polymer portion in the B segment is 70% by weight or more. The polymer fine particles according to claim 2. 4. An aqueous dispersion obtained by dispersing the polymer fine particles according to claim 1 in water.