JP2006161027A - Organic solvent-swelling micro gel and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new organic solvent-swelling micro gel and to provide a method for producing the micro gel. <P>SOLUTION: The organic solvent-swelling micro gel is composed of a copolymer obtained by carrying out radical polymerization of a specific polyethylene oxide macromonomer with specific two kinds of hydrophobic monomers and a specific crosslinkable monomer in a water-ethanol mixed solvent under conditions of the following (A), (B) and (C). (A) The mixture of these hydrophobic monomers has a composition obtained by mixing methyl methacrylate with a methacrylic acid derivative having 4-8C alkyl at a molar ratio of (90-10): (10-90). (B) The polyethylene oxide macromonomer and the hydrophobic monomer are charged at a molar ratio of (1:10) to (1:250). (C) The charging amount of the crosslinkable monomer is 0.1-1.5 mass% based on that of the hydrophobic monomer. (D) The mixed solvent is contained at (90-30):(10-70) ratio (volume ratio at 20°C) of water:ethanol. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel organic solvent swellable microgel and a method for producing the same. The organic solvent swellable microgel of the present invention is a corona-core type polymer microgel comprising a hydrophobic core and a hydrophilic corona, and is useful as a compounding component for various chemical products in which the polymer microgel is blended, such as cosmetics. It is a thing.

  Technology for industrially synthesizing polymer fine particles (polymer emulsions) has been put into practical use since the 1930s, and in the general chemical industry such as rubber industry, paints, paper surface treatment, adhesives, and medical such as diagnostics and drug delivery formulations. Applied in the field. The polymer emulsion can be synthesized and produced by a so-called emulsion polymerization method. The emulsion polymerization method is a method of polymerizing a polymer by preparing an emulsion composition of a desired monomer using an appropriate dispersion stabilizer. (Non-Patent Document 1)

  Also in the cosmetics industry, polymer emulsions produced by an emulsion polymerization method are applied to cosmetics. The present inventors have put to practical use a technique for producing an organic solvent-free nail enamel by blending a core-shell type polymer emulsion into an aqueous nail polish (Patent Document 1). Moreover, the technique which mix | blends the self-crosslinking type polymer emulsion which applied the crosslinking reaction of the alkoxysilane with cosmetics is put into practical use (patent documents 2 and 3).

  On the other hand, a method of polymerizing corona-core type polymer fine particles in a water-ethanol mixed solvent of polyethylene oxide macromonomer is known and is described in Non-Patent Document 2. This technology is applied as an AIDS virus capturing system, for example (Non-patent Document 3).

  Microgels are expected to be applied in the pharmaceutical and cosmetic industries by applying their swelling and shrinkage functions. There have been several reports on microgels using synthetic polymers (Non-Patent Document 4). These are all applied with a polymer electrolyte, such as polyacrylic acid, and have no acid resistance or salt resistance in water dispersibility. However, when considering applications in the pharmaceutical and cosmetic industry, acid resistance and salt resistance are very important performances in order to adapt under physiological conditions.

  On the other hand, there have been several reports on polymer fine particle polymerization by the so-called macromonomer method using a macromonomer containing a water-soluble polymer structure (Non-patent Document 5). This method can be said to be an excellent method in that polymer fine particles having a uniform particle diameter can be produced without controlling the stirring conditions of the polymerization system, which is a problem in mass production of heterogeneous polymerization (Non-patent Document 5). ).

JP 2001-114650 A JP 2002-327019 A JP 2003-20314 A "Emulsion Polymerization and Emulsion Polymers" P.A.Lovell and M.S.El-Asser edited by John Wiley and son M.Q. Chen et al: J. Polym. Sci .: A: Polym. Chem., 38 1811-1817 (2000) M. Akashi, M. Baba, et al: Bioconj. Chem., 9, 50-53 (1998) M.J.Snowden et al. Colloid Polym. Sci. 272, 1273 (1994) C. Wu, Macromolecules 27, 7099 (1944)

The present invention provides a novel polymer microgel and a method for producing the same. The microgel of the present invention has a narrow particle size distribution and exhibits excellent organic solvent swellability, and is extremely useful as a microgel blended in various chemical products.
The microgel of the present invention is a microgel stabilized with a polyethylene oxide chain which is a nonionic polymer, and its dispersion stability in water can be expected to have acid resistance and salt resistance.
The microgel of the present invention is a novel organic solvent swellable microgel manufacturing method characterized in that the core part, which has not been reported before, is manufactured as a microgel by using a crosslinkable monomer by applying the macromonomer method. .

（１）
Ｒ₁は炭素原子数１〜３のアルキルを表し、ｎは２０〜２００の数である。ＸはＨまたはＣＨ₃を表す。

（２）
Ｒ₂は炭素原子数１〜３のアルキルを表す。

（３）
Ｒ₃は炭素原子数１〜３のアルキルを表し、Ｒ₄は炭素原子数４〜８のアルキルを表す。ただし、Ｒ₃は式（２）のＲ₂と同一であっても、異なっていてもよい。

（４）
Ｒ₅とＲ₆はそれぞれ独立に炭素原子数１〜３のアルキルを表し、ｍは１〜３の数である。 That is, the present invention provides a copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4). A polymer, which is obtained by radical polymerization of the monomers (1) to (4) in a water-ethanol mixed solvent under the following conditions (A), (B), (C), and (D): An organic solvent swellable microgel comprising the obtained copolymer is provided.
(A) The hydrophobic monomer has a composition in which methyl methacrylate and a methacrylic acid derivative having an alkyl having 4 to 8 carbon atoms are mixed at 90 to 10:10 to 90 (molar ratio) (B) a polyethylene oxide macromonomer and The charged amount of the hydrophobic monomer is polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio). (C) The charged amount of the crosslinkable monomer is relative to the charged amount of the hydrophobic monomer. (D) The water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (20 ° C. volume ratio).

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represents alkyl having 1 to 3 carbon atoms, and m is a number from 1 to 3.

（１）
Ｒ₁は炭素原子数１〜３のアルキルを表し、ｎは２０〜２００の数である。ＸはＨまたはＣＨ₃を表す。

（２）
Ｒ₂は炭素原子数１〜３のアルキルを表す。

（３）
Ｒ₃は炭素原子数１〜３のアルキルを表し、Ｒ₄は炭素原子数４〜８のアルキルを表す。ただし、Ｒ₃は式（２）のＲ₂と同一であっても、異なっていてもよい。

（４）
Ｒ₅とＲ₆はそれぞれ独立に炭素原子数１〜３のアルキルを表し、ｍは０〜２の数である。 The present invention also provides a copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4). An organic solvent swellable microgel composed of monodisperse particles having a particle diameter of 50 to 200 nm, which is a polymer.

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2.

（１）
Ｒ₁は炭素原子数１〜３のアルキルを表し、ｎは２０〜２００の数である。ＸはＨまたはＣＨ₃を表す。

（２）
Ｒ₂は炭素原子数１〜３のアルキルを表す。

（３）
Ｒ₃は炭素原子数１〜３のアルキルを表し、Ｒ₄は炭素原子数４〜８のアルキルを表す。ただし、Ｒ₃は式（２）のＲ₂と同一であっても、異なっていてもよい。

（４）
Ｒ₅とＲ₆はそれぞれ独立に炭素原子数１〜３のアルキルを表し、ｍは０〜２の数である。 Furthermore, the present invention provides a copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4). When the particle diameter of the copolymer particles in water is d ₀ , and a water-immiscible organic solvent in which the copolymer particles swell and saturate is mixed in the water, and the mixture is stirred until it swells and saturates. An organic solvent swellable microgel having a swelling ratio (d / d ₀ ) ³ of 1 or more, where d is the particle diameter of the copolymer particles.

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2.

（１）
Ｒ₁は炭素原子数１〜３のアルキルを表し、ｎは２０〜２００の数である。ＸはＨまたはＣＨ₃を表す。

（２）
Ｒ₂は炭素原子数１〜３のアルキルを表す。

（３）
Ｒ₃は炭素原子数１〜３のアルキルを表し、Ｒ₄は炭素原子数４〜８のアルキルを表す。ただし、Ｒ₃は式（２）のＲ₂と同一であっても、異なっていてもよい。

（４）
Ｒ₅とＲ₆はそれぞれ独立に炭素原子数１〜３のアルキルを表し、ｍは０〜２の数である。 The present invention also includes a polyethylene oxide macromonomer represented by the following formula (1), a hydrophobic monomer represented by the following formulas (2) and (3), and a crosslinkable monomer represented by the following formula (4): The present invention provides a method for producing an organic solvent swellable microgel characterized by radical polymerization in a water-ethanol mixed solvent under the conditions of (B) and (C).
(A) The charged amount of polyethylene oxide macromonomer and hydrophobic monomer is polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio) (B) The charged amount of crosslinkable monomer is It is 0.1-1.5 mass% with respect to the preparation amount of a hydrophobic monomer. (C) Water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (20 degreeC volume ratio). Be

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2.

  Furthermore, this invention provides the cosmetics characterized by mix | blending said organic-solvent swelling microgel.

  The microgel of the present invention is a core-corona type microgel in which a nonionic and water-soluble polyethylene oxide chain is grafted on the surface, and the core portion is a hydrophobic polymer crosslinked with a crosslinking monomer. By adjusting the monomer mixing ratio and the polarity of the polymerization solvent, this microgel can easily produce microgel particles having a narrow particle size distribution without controlling particularly strict stirring conditions. This is easy for mass production and is advantageous for industrial applications.

  Although the microgel of the present invention is water-dispersible, it is expected to have acid resistance and salt resistance because it is dispersed and stabilized with a nonionic polymer. This feature is considered to be an excellent material that satisfies the requirement of stable dispersion under physiological conditions required for application in the pharmaceutical or cosmetic industry.

In addition, a notable characteristic of the microgel of the present invention is swelling ability with a water-immiscible organic solvent. This swelling ability has very high solvent selectivity. Moreover, the swelling efficiency shows a surprising result, and the organic solvent absorbs up to 400 times its own volume and swells.
In the present invention, a solvent that swells by mixing an alkyl acrylate alkyl group having 1 to 4 to 8 carbon atoms, as compared with the case of 1 to 3 carbon atoms. It is expected that the selectivity will be expanded.

  The microgel of the present invention is particularly useful as a cosmetic raw material.

Hereinafter, the present invention will be described in detail.
As the polyethylene oxide macromonomer of the formula (1) used in the present invention, for example, a reagent commercially available from Aldrich or Blemmer (registered trademark) marketed by Nippon Oil & Fats can be used. The molecular weight (namely, the value of n) of these commercially available polyethylene oxide moieties of formula (1) is wide and can be used. The preferred molecular weight size of this polyethylene oxide moiety is n = 20-200. For example, Blemmer (registered trademark) PME1000 or Blemmer (registered trademark) PME4000 made by NOF is suitable.

The hydrophobic monomers of formulas (2) and (3) used in the present invention can be easily obtained as general industrial raw materials. The alkyl groups of R _{2 in} the formulas (2) and (3) may be the same or different. Moreover, the alkyl chain of R < ₃ > of Formula (3) is a C4-C8 alkyl.
Formula (2) is preferably methyl methacrylate, and formula (3) is preferably butyl methacrylate, hexyl methacrylate, or ethyl hexyl methacrylate. Accordingly, the hydrophobic monomer is preferably a combination of methyl methacrylate of the formula (2) and butyl methacrylate, hexyl methacrylate or ethylhexyl methacrylate of the formula (3).

  The crosslinkable monomer of the formula (4) used in the present invention can be obtained as a commercially available reagent or an industrial raw material. This crosslinkable monomer is preferably hydrophobic. The value of m in the formula (4) is preferably 1 to 3. Specifically, ethylene glycol dimethacrylate sold by Aldrich, Bremer (registered trademark) PDE-50 manufactured by NOF Corporation is suitable.

The monomer is obtained by radical polymerization of the monomers (1) to (4) in a water-ethanol mixed solvent under the following conditions (A), (B), (C), and (D). It is done.
(A) The hydrophobic monomer has a composition in which methyl methacrylate and a methacrylic acid derivative having an alkyl having 4 to 8 carbon atoms are mixed at 90 to 10:10 to 90 (molar ratio) (B) a polyethylene oxide macromonomer and The charged amount of the hydrophobic monomer is polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio). (C) The charged amount of the crosslinkable monomer is relative to the charged amount of the hydrophobic monomer. (D) The water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (20 ° C. volume ratio).

  The charged amount of the polyethylene oxide macromonomer and the hydrophobic monomer of A is within the range of polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio), and the corona-core type microgel can be polymerized. When the charged amount of the ethylene oxide macromonomer exceeds 1/10 of the hydrophobic monomer in a molar ratio, the polymer to be polymerized becomes water-soluble and no corona-core type polymer microgel is formed. Further, when the hydrophobic monomer becomes 250 times or more with respect to the molar amount of the polyethylene oxide macromonomer, the dispersion stabilization by the polyethylene oxide macromonomer becomes incomplete, and the hydrophobic polymer by the insoluble hydrophobic monomer aggregates and precipitates. The charge ratio of the polyethylene oxide macromonomer and the hydrophobic monomer is preferably in the range of 1:20 to 1: 200. More preferably, it is in the range of 1:25 to 1: 150.

  By copolymerizing the crosslinkable monomer of B, it is possible to polymerize the microgel in which the hydrophobic polymer in the core portion is crosslinked. If the charge amount of the crosslinkable monomer is less than 0.1% by weight of the charge amount of the hydrophobic monomer, the crosslink density is low, and the microgel collapses when swollen. On the other hand, when the content exceeds 1.5% by weight, the microgel particles are aggregated and suitable microgel particles having a narrow particle size distribution cannot be polymerized. The amount of the crosslinkable monomer charged is preferably 0.2 to 1.0, more preferably 0.2 to 0.8, and most preferably 0.2 to 0.5% by mass.

  The mixing ratio of water / ethanol, which is a polymerization solvent for C, is such that the water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (volume ratio at 20 ° C.). The polymerization solvent needs to add ethanol in order to uniformly dissolve the hydrophobic monomer. The mixing ratio of ethanol is 10-60 volume ratio. When the mixing ratio of ethanol is lower than 10 volume ratio, it becomes difficult to solubilize the hydrophobic monomer, and the particle size distribution of the microgel particles to be polymerized becomes wide. When the mixing ratio of ethanol exceeds 60 volume ratio, the polymer to be polymerized is dissolved in the polymerization solvent, and microgel particles cannot be obtained. A preferable water / ethanol mixing ratio is such that the water-ethanol mixed solvent is water: ethanol = 90-50: 10-50 (volume ratio of 20 ° C.). More preferably, it is water: ethanol = 80-60: 20-40 (volume ratio of 20 ° C.).

As the polymerization initiator used in this polymerization system, a commercially available polymerization initiator used for usual water-soluble thermal radical polymerization can be used.
In this polymerization system, it is possible to obtain a very narrow particle size distribution of the polymerized microgel particles even when the polymerization is performed without strictly controlling the stirring conditions.

  By the above-described production method, an organic solvent swellable microgel composed of monodisperse particles having a particle diameter of 50 to 200 nm is obtained.

但し、Ｄは拡散係数、ｋはボルツマン定数、Ｔは絶対温度（Ｋ）、ηは溶媒の粘度、およびｒは粒子の半径である。
この測定は市販の測定装置で簡便に測定可能である。たとえば大塚電子製 DLS7000、マーベルン製 オートサイザー４７００、ブルックヘーブン製 ゼータパルスなどで測定が可能である。
上述の市販の測定装置にはデータ解析ソフトが搭載されており、測定データを自動的に解析することが出来る。この解析ソフトを用いることで平均粒子径、分散度の値を得ることが出来る。ここで分散度とは粒子径の平均値からのばらつきを示す値であり、キュムラント解析における二次キュムラントの値、即ち、分散値を規格化した値である。一般的にこの分散度が０．０１以下であればそのサンプルの粒子径分布はほぼ単分散とみなすことが出来る。 “Claim 2”
Generally, the particle diameter of so-called colloidal particles such as emulsified particles or polymer emulsions can be measured by a method called dynamic light scattering method or photon correlation method. This measurement method measures the translational diffusion coefficient (average value) of sample particles by irradiating a sample dispersion prepared to a sufficiently dilute concentration with laser light and measuring the intensity of scattered light scattered from the sample particles. It is a method to do. Sample particles are constantly moving in the dispersion with Brownian motion. The moving speed of the particles by the Brownian motion, that is, the translational diffusion coefficient (average value) can be analyzed from the result of the temporal change in the scattered light intensity. The hydrodynamic size of the sample particles can be calculated from the translation diffusion coefficient (average value) thus obtained according to the Stokes-Einstein equation (Equation 1).

Where D is the diffusion coefficient, k is the Boltzmann constant, T is the absolute temperature (K), η is the viscosity of the solvent, and r is the radius of the particles.
This measurement can be easily performed with a commercially available measuring apparatus. For example, measurement is possible with Otsuka Electronics DLS7000, Marveln Autosizer 4700, Brookhaven Zeta Pulse.
The above-mentioned commercially available measuring apparatus is equipped with data analysis software, and can automatically analyze measurement data. By using this analysis software, values of average particle diameter and degree of dispersion can be obtained. Here, the degree of dispersion is a value indicating a variation from the average value of the particle diameter, and is a value of the secondary cumulant in the cumulant analysis, that is, a value obtained by normalizing the dispersion value. In general, if the degree of dispersion is 0.01 or less, the particle size distribution of the sample can be regarded as almost monodisperse.

Further, the particle diameter of the copolymer particles when the microgel polymerized by the above-described production method is dispersed in water is d ₀ , and the mixed solvent is mixed with benzene that swells and saturates the copolymer particles, until the swelling and saturation is reached. An organic solvent swellable microgel having a swelling ratio (d / d ₀ ) ³ of 20 to 450 is obtained, where d is the particle diameter of the copolymer particles when stirred.

“Claim 3”
“When mixed benzene is mixed with this mixed solvent so that the copolymer particles swell and saturate, and is stirred until the swell is saturated”, even if the amount of benzene and the stirring time are increased, the swollen microgel This means that the amount of benzene and the stirring time are required so that the particle size swelling ratio (d / d ₀ ) ^{3 of the} slag does not increase further.
For example, if the microgel is dispersed in water, benzene having the same volume as this mixed solvent is added and stirred for 5 hours, it is sufficient to swell and saturate.
When the polymerization solvent is a mixed solvent of water: ethanol = 6: 4 (20 ° C. volume ratio), the polymerization dispersion is sufficiently dialyzed against pure water after polymerization, and the dispersion is exchanged for pure water. It is sufficient to dilute this microgel aqueous dispersion with water to an appropriate concentration, add benzene of the same volume as the measurement sample to a sample prepared so that the concentration of the microgel is constant, and mix and stir for 5 hours. .
The particle diameters d and d ₀ can be measured by a dynamic light scattering method. The measurement conditions are as follows.
First, the particle size in water of the microgel before adding the organic solvent is measured as a control value, that is, a value of d ₀ . This measurement can be easily performed using a commercially available dynamic light scattering measurement apparatus. For example, it is possible to measure with DLS7000 manufactured by Otsuka Electronics, Autosizer 4700 manufactured by Marveln, Zeta Pulse manufactured by Brookhaven. These commercially available measuring apparatuses are equipped with data analysis software, and can automatically obtain the average particle diameter and the degree of dispersion. On the other hand, the particle diameter d after swelling with an organic solvent is processed by the following method. That is, an organic solvent such as benzene of the same volume is added to a microgel aqueous dispersion having a constant concentration, preferably about 0.01% by weight, and sealed in a covered sample tube. The sample tube is stirred for a certain time while gently stirring at room temperature. A stirring time of about 5 hours is sufficient. After stirring, the sample tube is lightly centrifuged at about 1000 × g to float the organic solvent, and the aqueous phase portion in which the microgel is dispersed is carefully collected with a syringe. The average particle diameter and the degree of dispersion of this collected sample are similarly measured using the above-mentioned commercially available dynamic light scattering measuring device.
The value of swelling ratio (d / d ₀ ) ³ can be calculated from the values of d and d ₀ thus obtained.

All of the conventional microgels made of synthetic polymers have applied polymer electrolytes such as polyacrylic acid, and have no acid resistance or salt resistance in water dispersibility. However, when considering application as a compounding ingredient of pharmaceuticals and cosmetics, acid resistance and salt resistance are very important performances in adaptation under physiological conditions. The microgel of the present invention is a microgel stabilized with a polyethylene oxide chain, which is a nonionic polymer, and its dispersion stability in water can be expected to have acid resistance and salt resistance.
Also known is a polymer microparticle polymerization method using a macromonomer method that applies a macromonomer containing a water-soluble polymer structure, but this method is applied to produce a microgel by crosslinking the core with a crosslinkable monomer. There is no known way to do it. The production method of the present invention is a core-corona type in which a hydrophilic macromonomer and a hydrophobic monomer are ordered in a solvent as shown in FIG. 1, the particle diameter is substantially constant, and the core portion is crosslinked. It is thought that a polymer microgel is formed.

“About claim 5”
The microgel is useful as a cosmetic raw material. The cosmetics of this invention can be manufactured by mix | blending said microgel with cosmetics. That is, microgels and cosmetic ingredients (for example, powder ingredients, liquid fats and oils, solid fats and oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, anionic surfactants, cationic surfactants, amphoteric surfactants) , Nonionic surfactant, moisturizer, water-soluble polymer, thickener, film agent, UV absorber, sequestering agent, lower alcohol, polyhydric alcohol, sugar, amino acid, organic amine, polymer emulsion, pH (Adjusting agents, skin nutrients, vitamins, antioxidants, antioxidant aids, fragrances, water, etc.) can be blended as appropriate, and any cosmetics can be produced by conventional methods according to the intended dosage form. .

  The blending amount of the microgel is appropriately determined according to the cosmetic. It is desirable to blend in the range of 0.01 to 10% by mass.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples. The blending amount is mass% unless otherwise specified.

"Monomers and reagents used in the examples"
Polyethylene oxide macromonomer (polyethylene glycol methyl ether methacrylate; manufactured by Nippon Oil & Fats, Bremer PME-4000), methyl methacrylate (abbreviated as C1MA; manufactured by Aldrich), n-butyl methacrylate (abbreviated as C4MA; manufactured by Aldrich), 2-ethylhexyl methacrylate (C8MA) (Abbreviated as Aldrich) and ethylene glycol dimethacrylate (abbreviated as EGDM; Aldrich) were used as monomers. As a polymerization initiator, 2,2′azobis (2-methylpropionamidine dihydrochloride) (manufactured by Aldrich) was used. Water used was ion exchange water. Other organic solvents used are as follows. Ethyl alcohol (Aldrich), benzene (Aldrich) and hexane (Aldrich).

Example 1
The polymerization of the microgel was carried out by the following method. In a 200 mL three-necked flask equipped with a reflux tube and a nitrogen introduction tube, 267.0 mg of PME-4000, 503.0 mg of methyl methacrylate (C1MA), 50 mL of a water-ethanol mixed solvent (water: ethanol = 40: 60 volume ratio), n -Dissolve 428.1 mg of butyl methacrylate (C4MA) and 2.1 mg of ethylene glycol dimethacrylate. After sufficiently dissolving, 2,2 ′ azobis (2-methylpropionamidine dihydrochloride) is added at a ratio of 1 mol% with respect to the total monomer amount and further dissolved. The completely homogenized polymerization solution is purged with nitrogen for 20 minutes to remove dissolved oxygen, and then stirred for 8 hours in an oil bath at 65 to 70 ° C. while stirring with a magnetic stirrer. After completion of the polymerization, the polymerization solution is returned to room temperature, and then the polymerization solution is dialyzed against water for 5 days to remove residual monomers, and at the same time, the dispersion is replaced with water. Let the sample obtained here be PMG1.

Example 2
The polymerization of the microgel was carried out by the following method. In a 200 mL three-necked flask equipped with a reflux tube and a nitrogen introduction tube, 218.0 mg of PME-4000 and 261.8 mg of methyl methacrylate (C1MA) were added to 50 mL of a water-ethanol mixed solvent (water: ethanol = 60: 40 volume ratio), 2 -Dissolve 502.1 mg of ethylhexyl methacrylate (C8MA) and 1.5 mg of ethylene glycol dimethacrylate. After sufficiently dissolving, 2,2 ′ azobis (2-methylpropionamidine dihydrochloride) is added at a ratio of 1 mol% with respect to the total monomer amount and further dissolved. The completely homogenized polymerization solution is purged with nitrogen for 20 minutes to remove dissolved oxygen, and then stirred for 8 hours in an oil bath at 65 to 70 ° C. while stirring with a magnetic stirrer. After completion of the polymerization, the polymerization solution is returned to room temperature, and then the polymerization solution is dialyzed against water for 5 days to remove residual monomers, and at the same time, the dispersion is replaced with water. Let the sample obtained here be PMG2.

Example 3
The polymerization of the microgel was carried out by the following method. In a 200 mL three-necked flask equipped with a reflux tube and a nitrogen introduction tube, 267.0 mg of PME-4000 and 482.2 mg of methyl methacrylate (C1MA) in 50 mL of a water-ethanol mixed solvent (water: ethanol = 40: 60 volume ratio), n Dissolve 171.5 mg of butyl methacrylate (C4MA) and 2.1 mg of ethylene glycol dimethacrylate. After sufficiently dissolving, 2,2 ′ azobis (2-methylpropionamidine dihydrochloride) is added at a ratio of 1 mol% with respect to the total monomer amount and further dissolved. The completely homogenized polymerization solution is purged with nitrogen for 20 minutes to remove dissolved oxygen, and then stirred for 8 hours in an oil bath at 65 to 70 ° C. while stirring with a magnetic stirrer. After completion of the polymerization, the polymerization solution is returned to room temperature, and then the polymerization solution is dialyzed against water for 5 days to remove residual monomers, and at the same time, the dispersion is replaced with water. Let the sample obtained here be PMG3.

Example 4
The polymerization of the microgel was carried out by the following method. In a 200 mL three-necked flask equipped with a reflux tube and a nitrogen introducing tube, water-ethanol mixed solvent (water: ethanol = 40: 60 volume ratio) 50 mL, PME-4000 267.0 mg, methyl methacrylate (C1MA) 120.3 mg, n -Dissolve 685.7 mg of butyl methacrylate (C4MA) and 2.1 mg of ethylene glycol dimethacrylate. After sufficiently dissolving, 2,2 ′ azobis (2-methylpropionamidine dihydrochloride) is added at a ratio of 1 mol% with respect to the total monomer amount and further dissolved. The completely homogenized polymerization solution is purged with nitrogen for 20 minutes to remove dissolved oxygen, and then stirred for 8 hours in an oil bath at 65 to 70 ° C. while stirring with a magnetic stirrer. After completion of the polymerization, the polymerization solution is returned to room temperature, and then the polymerization solution is dialyzed against water for 5 days to remove residual monomers, and at the same time, the dispersion is replaced with water. Let the sample obtained here be PMG4.

Comparative Example 1
The polymerization of the microgel was carried out by the following method. In a 200 mL three-necked flask equipped with a reflux tube and a nitrogen introduction tube, 280 mg of PME-4000, 853.2 mg of methyl methacrylate (C1MA) and ethylene glycol in 50 mL of a water-ethanol mixed solvent (water: ethanol = 30: 70 volume ratio) and ethylene glycol Dissolve 2.0 mg of dimethacrylate. After sufficiently dissolving, 2,2 ′ azobis (2-methylpropionamidine dihydrochloride) is added at a ratio of 1 mol% with respect to the total monomer amount and further dissolved. The completely homogenized polymerization solution is purged with nitrogen for 20 minutes to remove dissolved oxygen, and then stirred for 8 hours in an oil bath at 65 to 70 ° C. while stirring with a magnetic stirrer. After completion of the polymerization, the polymerization solution is returned to room temperature, and then the polymerization solution is dialyzed against water for 5 days to remove residual monomers, and at the same time, the dispersion is replaced with water. Let the sample obtained here be PMG5.

但し架橋率（％）は、ＰＭＥ４０００および疎水性モノマーの合計質量に対するＥＧＤＭの質量％である。 The polymerization results are shown in “Table 1”.
Sample numbers PMG1, 2, 3, 4 are the microgels of the present invention. PMG5 is a comparative example in which only the hydrophobic monomer of formula (2) is used without using the hydrophobic monomer of formula (3). All samples had a cloudy color at the end of the reaction.

However, the crosslinking rate (%) is mass% of EGDM with respect to the total mass of PME4000 and the hydrophobic monomer.

Next, the characteristics of the microgel obtained above were examined. The measurement method is shown below.
"Measurement method of particle size and degree of dispersion"
The microgel particle size was measured using Zeta Plus manufactured by Brookhaven. The microgel concentration of the microgel dispersion is adjusted to about 0.1%, a measurement sample is prepared, dust is removed with a 0.45 micrometer filter, the scattering intensity at 25 ° C. is measured at a scattering angle of 90 °, The average particle size and the degree of dispersion were calculated with analysis software installed in the measuring device. The particle diameter is analyzed by a cumulant analysis method, and the degree of dispersion is a numerical value obtained by standardizing the value of the secondary cumulant obtained by the cumulant analysis. This degree of dispersion is a commonly used parameter and can be automatically analyzed by using a commercially available dynamic light scattering measurement device. As the viscosity of the solvent necessary for the particle size analysis, the viscosity of pure water at 25 ° C., that is, a value of 0.89 mPas was used.
The measurement was performed 10 times for each sample, and the average value was taken.
As a control value, the particle diameter of untreated microgel in water was measured, and this was defined as the d ₀ value.

"Measurement method of swelling degree"
The degree of swelling with an organic solvent was measured by the following method. In the microgel of the present invention, polymethacrylic alkyl forms the core portion. The solvent used was benzene, which is a good solvent, and hexane, which is a poor solvent, for polymethacrylic methyl. Further, RA-PE408, MCX, or artificial sebum, which is an oil widely used in cosmetics, was used.
20 mL of a microgel aqueous dispersion prepared to a microgel concentration of 0.1% is taken into a 50 mL glass lidded sample tube, and 0.2 mL of various water-immiscible solvents (oil) are added thereto. The sample tube was stirred for 8 hours at room temperature with an overturning stirrer. After stirring, the mixture was lightly centrifuged to allow excess organic solvent to float, and the aqueous phase portion of the sample solution was carefully aspirated using a syringe to obtain a measurement sample. The measurement sample measured the average particle diameter and dispersion degree at 25 degreeC by the said method. The particle diameter after the swelling treatment measured here was taken as d and the ratio with the above-mentioned d ₀ was taken, and the value obtained by cubeing this was taken as the degree of swelling (d / d ₀ ) ³ .

"Results and discussion"
The characteristic values of the microgel polymerized in the present invention are shown in “Table 2”.
The sample particle size was about 50-150 nm. Although the degree of dispersion of the microgel of the present invention was higher than that of PMG5, monodisperse particles having a degree of dispersion of less than 0.10 were obtained.

The degree of swelling with benzene and hexane was measured for samples of PMG1-5. The results are shown in “Table 3”.

  The graph of FIG. 2 shows the swelling ratio of PMG 1 to 5 with benzene. The swelling ratio by hexane is shown in the graph of FIG. The vertical axis of the graph indicates the degree of swelling.

  The microgel was significantly swollen by benzene, which is a good solvent for polymethacrylmethyl forming the core part of the microgel of PMG5, and the microgels PMG1 to PMG4 of the present invention also swollen well with respect to benzene. By changing the mixing ratio of methyl methacrylate and a methacrylate ester having a long alkyl chain length as a hydrophobic monomer, the swelling ratio with respect to benzene changes. In addition, when mixed with hexane, which is a poor solvent for polymethacrylmethyl, PMG5 having a short alkyl chain length does not swell, but by mixing with a hydrophobic monomer having an alkyl chain length of 8 or more, the microgel (PMG2) can Even swelled. From these results, the microgels PMG1 to PMG4 of the present invention are highly swellable to benzene, and these are organic solvent swellable microgels having solvent selectivity, while PMG2 can swell to several organic solvents. It can be said that it is a microgel. By changing the composition of the core portion, it is possible to obtain an organic solvent swellable microgel according to the purpose.

About the samples of PMG1-5, the swelling degree by RA-PE408, MCX, and artificial sebum was measured. The results are shown in “Table 4”.

  The swelling ratios of PMG1 to RA-PE408, MCX, and artificial sebum are shown in the graphs of FIGS. The vertical axis of the graph indicates the degree of swelling.

  PMG5 does not swell at all against polar oils such as RA-PE408 and MCX, which are widely used as cosmetic raw materials, and artificial sebum. By mixing hydrophobic monomers with monomers having several alkyl chain lengths, Also swelled with respect to the oil content. This is considered to be bulky as the alkyl chain length of the core portion of the microgel increases, and because the glass transition temperature decreases, the range of solvents that can swell due to increased flexibility is increased.

  Examples of cosmetics containing the microgel of the present invention are shown below.

"Example 5 lotion"
Ethyl alcohol 5% by mass
Glycerin 1
1,3-butylene glycol 5
Polyoxyethylene polyoxypropylene decyl tetradecyl ether
0.2
Sodium hexametaphosphate 0.03
Trimethylglycine 1
Sodium polyaspartate 0.1
α-Tocopherol 2-L-ascorbic acid phosphate diester potassium
0.1
Thiotaurine 0.1
Green tea extract 0.1
Western mint extract 0.1
HEDTA 3 sodium 0.1
Microgel (PMG1) 0.1
Carboxyvinyl polymer 0.05
Potassium hydroxide 0.02
Phenoxyethanol Appropriate amount Purified water Residual perfume Appropriate amount

"Example 6 moisturizing cream"
Liquid paraffin 10
Dimethylpolysiloxane 2
Glycerin 10
1,3-butylene glycol 2
Erythritol 1
Polyethylene glycol 1500 5
Squalane 15
Tetra-2-ethylhexanoic acid pentaerythrit 5
Potassium hydroxide 0.1
Sodium hexametaphosphate 0.05
Tocopherol acetate 0.05
P-Hydroxybenzoate appropriate amount hydroxypropyl methylcellulose 0.2
Microgel (PMG2) 0.1
Polyvinyl alcohol 0.1
Carboxyvinyl polymer 0.2
Acrylic acid / alkyl methacrylate copolymer (Pemulene TR-2)
0.1
Purified water residue

"Example 7 sunscreen"
Decamethylcyclopentasiloxane 20
Ethanol 5
Isostearyl alcohol 2
Dipropylene glycol 3
Isostearic acid 2
Glyceryl tri-2-ethylhexanoate 5
Cetyl 2-ethylhexanoate 2
Dextrin fatty acid ester coated fine particle titanium oxide (40nm) 2
Sodium chloride 2
Edetate trisodium appropriate amount ubinal T-150 (manufactured by BASF) 1
4-t-butyl-4'-methoxydibenzoylmethane 1
2-Ethylhexyl paramethoxycinnamate 7.5
Carboxymethylcellulose Na 0.4
Microgel (PMG4) 0.1
Ethyl cellulose 1
Spherical acrylic resin powder 5
Purified water Residual fragrance

"Example 8 cleansing gel"
Polyoxyethylene / methylpolysiloxane copolymer 5
Dipropylene glycol 3
1,3-butylene glycol 10
Polyethylene glycol 1500 1
Polyoxyethylene methyl glucoside 1
Microgel (PMG4) 0.05
Polyethylene glycol diisostearate 5
Dipotassium glycyrrhizinate 0.1
Cola de Cavallo extract 0.1
Edetic acid tri-Na 0.01
Hydroxypropyl methylcellulose 0.8
Carboxyvinyl polymer potassium 0.35
P-Hydroxybenzoate appropriate amount purified water remaining

"Example 9 Latex"
Dimethylpolysiloxane 3
Decamethylcyclopentasiloxane 4
Ethanol 5
Glycerin 6
1,3-butylene glycol 5
Polyoxyethylene methyl glucoside 3
Sunflower oil 1
Squalane 2
Potassium hydroxide 0.1
Sodium hexametaphosphate 0.05
Hydroxypropyl-β-cyclodextrin 0.1
Dipotassium glycyrrhizinate 0.05
Loquat leaf extract 0.1
Sodium L-glutamate 0.05
Fennel extract 0.1
Yeast extract 0.1
Lavender oil 0.1
Giant extract 0.1
Dimorpholinopyridazinone 0.1
Xanthan gum 0.1
Microgel (PMG3) 0.1
Acrylic acid / alkyl methacrylate copolymer (Pemulene TR-1)
0.1
Bengala Appropriate amount Yellow iron oxide Appropriate amount Paraben Appropriate amount Purified water Residual

"Example 10 Shampoo"
Ethylene glycol distearate 1.5
Palm oil fatty acid ethanolamide 5.5
Palm oil fatty acid methyl taurine sodium 8
Palm oil fatty acid amidopropyl betaine 5
Polymer JR-400 (Union Carbide) 0.4
Microgel (PMG3) 0.1
Citric acid 0.5
Sodium chloride 1.2
Loquat leaf extract 0.1
Phenoxyethanol 0.1
Sodium benzoate Appropriate amount Disodium edetate Appropriate amount Purified water Residual perfume Appropriate amount

"Example 11 Conditioner"
Highly polymerized dimethylsiloxane / methyl (aminopropyl) siloxane copolymer
0.2
Hardened rapeseed oil alcohol 3
Glycerin 3.5
3-Methyl-1,3-butanediol 5
Hydroxystearic acid 0.5
Cetyl 2-ethylhexanoate 1
Isononyl isononanoate 0.5
Sensormer CI-50 (Nalco) 0.2
Stearic acid dimethylaminopropylamide 1
Marcote 550 (Calgon) 1
Microgel (PMG3) 0.1
L-glutamic acid 0.5
Phenoxyethanol 0.4
Lecithin 0.1
Clean water Remaining fragrance Appropriate amount Pigment Appropriate amount

"Example 12 facial cleansing foam"
Glycerin 35
Polyethylene glycol 20000 0.5
Maltitol hydroxyalkyl (12,14) ether solution 0.5
Ethylene glycol distearate 1
N-coconut oil fatty acid acylglycine sodium 15
Sodium dodecane-1,2-diol acetate 1
Arginine-coconut oil fatty acid 1
Sodium N-lauroyl-L-glutamate 2
Palm oil fatty acid amidopropyl betaine 1.5
Microgel (PMG3) 0.05
Citric acid 1
Oat extract 0.05
L-Menthol 0.1
Granule * 1
Purified water Residual fragrance Appropriate amount * [Granule composition]
Zinc oxide 5
Talc 5
Magnesium aluminate metasilicate 10
Polyethylene powder 75
Ethylcellulose 5

"Example 13 body soap"
Propylene glycol 5
Polyoxypropylene glyceryl ether 0.5
Isostearic acid 1
Lauric acid 10
Palm fatty acid 9
Myristic acid 1
Ethylene glycol distearate 2
Palm oil fatty acid diethanolamide 1
Sodium polyoxyethylene lauryl ether sulfate 1.5
Palm oil fatty acid methyl taurine sodium 0.3
Taurine sodium laurate 0.3
2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine
2
Marcote 100 (Calgon) 0.1
Potassium hydroxide 5
Hydroxypropyl methylcellulose 0.3
Microgel (PMG1) 0.1
Loquat leaf extract appropriate amount edetate disodium appropriate amount purified water residual fragrance appropriate amount

"Example 14 Liquid Foundation"
Ethanol 10.0
Glycerin 10.0
1,3-butylene glycol 7.0
Silica-coated titanium oxide 8.0
Synthetic phlogopite 3.0
Spherical silica 5.0
Bengala coated mica titanium (color rendering pearl G) 2.0
Sodium chloride 0.3
Hydroxypropyl-β-cyclodextrin 0.1
Green tea extract 0.1
Lily extract 0.1
Bengala 0.1
Gellan gum 0.1
Microgel (PMG2) 0.1
Porous spherical cellulose 0.1
Lavender extract 0.1
Purified water residue

"Example 15 makeup base"
Dimethylpolysiloxane 2
Decamethylcyclopentasiloxane 5
Ethanol 3
Behenyl alcohol 0.1
Batyl alcohol 0.1
Dipropylene glycol 5
1,3-butylene glycol 3
Polyethylene glycol 1500 4
Vegetable squalane 0.1
Polyoxyethylene glyceryl isostearate 0.3
Titanium oxide Bengala coated mica 0.3
Mica titanium 0.3
Potassium hydroxide 0.2
Sodium hexametaphosphate 0.05
Tocopherol acetate 0.1
Paraoxybenzoic acid ester Appropriate amount Lithium cobalt titanate Appropriate amount Porous spherical cellulose powder 0.5
Microgel (PMG2) 0.2
Carboxyvinyl polymer 0.2
Acrylic acid / alkyl methacrylate copolymer 0.2
Purified water residue

"Example 16 mascara"
Ethanol 5
1,3-butylene glycol 4
Polyethylene terephthalate / polymethyl methacrylate laminated film powder
0.1
Potassium hydroxide 0.1
Sodium hexametaphosphate appropriate amount paraoxybenzoate appropriate amount Acid Red 0.1
Tartrazine 0.1
Brilliant Blue FCF 0.1
Dextrin 30
Microgel (PMG4) 0.2
Carboxyvinyl polymer 1
Purified water remaining

"Example 17 eyeliner"
Liquid paraffin 5
Methyl polysiloxane emulsion Appropriate amount Glycerin 3
1,3-butylene glycol 6
Polyoxyethylene sorbitan monolaurate (20E.O.) 2
Isobutylene / sodium maleate copolymer solution 1
Titanium oxide Appropriate amount Plate-like barium sulfate Appropriate amount Kaolin 8
Black iron oxide coated mica titanium (pearl) 3
Black iron oxide 9
DL-β-tocopherol acetate 0.1
Paraoxybenzoate suitable amount Bentonite 1
Sodium carboxymethylcellulose 1.5
Alkyl acrylate copolymer emulsion 7
Microgel (PMG4) 0.5
Purified water remaining

The microgel of the present invention is a core-corona type microgel in which a nonionic and water-soluble polyethylene oxide chain is grafted on the surface, and the core portion is a hydrophobic polymer crosslinked with a crosslinking monomer. By adjusting the monomer mixing ratio and the polarity of the polymerization solvent, this microgel can easily produce microgel particles having a narrow particle size distribution without controlling particularly strict stirring conditions. This is easy for mass production and is advantageous for industrial applications.
Although the microgel of the present invention is water-dispersible, it is expected to have acid resistance and salt resistance because it is dispersed and stabilized with a nonionic polymer. This feature is considered to be an excellent material that satisfies the requirement of stable dispersion under physiological conditions required for application in the pharmaceutical or cosmetic industry. In addition, a notable characteristic of the microgel of the present invention is swelling ability with a water-immiscible organic solvent. This swelling ability has very high solvent selectivity. Moreover, the swelling efficiency shows a surprising result, and the organic solvent absorbs up to 400 times its own volume and swells.
From the above characteristics, the microgel according to the present invention is expected to be applied in a wide range of industrial fields.

It is a schematic diagram which shows the core-corona type polymer nanosphere production | generation mechanism of the microgel of this invention. It is a graph which shows the swelling rate by the benzene of the microgel of this invention. It is a graph which shows the swelling rate by the hexane of the microgel of this invention. It is a graph which shows the swelling rate by RA-PE408 of the microgel of this invention. It is a graph which shows the swelling rate by MCX of the microgel of this invention. It is a graph which shows the swelling rate by the artificial sebum of the microgel of this invention.

Claims (5)

A copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4), From a copolymer obtained by radical polymerization of the monomers (1) to (4) in a water-ethanol mixed solvent under the following conditions (A), (B), (C), and (D): Organic solvent swellable microgel.
(A) The hydrophobic monomer has a composition in which methyl methacrylate and a methacrylic acid derivative having an alkyl having 4 to 8 carbon atoms are mixed at 90 to 10:10 to 90 (molar ratio) (B) a polyethylene oxide macromonomer and The charged amount of the hydrophobic monomer is polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio). (C) The charged amount of the crosslinkable monomer is relative to the charged amount of the hydrophobic monomer. (D) The water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (20 ° C. volume ratio).

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2. A copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4), An organic solvent swellable microgel comprising monodisperse particles having a particle diameter of 50 to 200 nm.

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2. A copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formulas (2) and (3), and a crosslinkable monomer of the following formula (4), The particle diameter of the copolymer particles in water is d ₀ , and the water-immiscible organic solvent in which the copolymer particles swell and saturate is mixed in the water, and the particles of the copolymer particles are stirred until they swell and saturate. An organic solvent swellable microgel having a swelling ratio (d / d ₀ ) ³ of 1 or more when the diameter is d.

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2. A polyethylene oxide macromonomer represented by the following formula (1), a hydrophobic monomer represented by the following formulas (2) and (3), and a crosslinkable monomer represented by the following formula (4) are represented by the following (A), (B), (C The method for producing an organic solvent swellable microgel according to claim 1, 2 or 3, wherein radical polymerization is carried out in a water-ethanol mixed solvent under the conditions of
(A) The charged amount of polyethylene oxide macromonomer and hydrophobic monomer is polyethylene oxide macromonomer: hydrophobic monomer = 1: 10 to 1: 250 (molar ratio) (B) The charged amount of crosslinkable monomer is It is 0.1-1.5 mass% with respect to the preparation amount of a hydrophobic monomer. (C) Water-ethanol mixed solvent is water: ethanol = 90-30: 10-70 (20 degreeC volume ratio). Be

(1)
R ₁ represents alkyl having 1 to 3 carbon atoms, and n is a number from 20 to 200. X represents H or CH ₃ .

(2)
R ₂ represents an alkyl having 1 to 3 carbon atoms.

(3)
R ₃ represents alkyl having 1 to ₃ carbon atoms, and R ₄ represents alkyl having 4 to 8 carbon atoms. However, R ₃ may be the same as or different from R _{2 in the} formula (2).

(4)
R ₅ and R ₆ each independently represent alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2. A cosmetic comprising the organic solvent swellable microgel according to claim 1.

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