JP2007106694A - Skin care agent for external use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a skin care agent for external use superior in effect for improving moisture retention effect and rough skin improving effect, and superior in use touch. <P>SOLUTION: The skin care agent for external use is characterised by containing a copolymer obtained by polymerizing a specified polyethylene oxide macromonomer, a hydrophobic monomer and a cross-linking monomer; and a moisture retentive agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an external preparation for skin. More specifically, the present invention relates to an external preparation for skin which is excellent in a moisturizing effect and a rough skin improving effect and excellent in touch feeling.

Moisture retention is indispensable for maintaining healthy skin, and many external preparations for the purpose of moisturizing have been developed. Further, as a feeling of use of the external preparation for skin, there is a demand for a smooth and non-sticky feeling.
There are many studies on moisturizers. And glycerin is mentioned as a well-known moisturizer used for a lotion, an emulsion, etc. (nonpatent literature 1). In addition to the moisturizing effect, this glycerin also has an effect of improving rough skin (Patent Document 1).
However, the amount of glycerin must be increased in order to increase the moisturizing effect and the effect of improving rough skin. As a result, there are problems to be solved such as the system becomes unstable, the usability deteriorates, and when it is applied to the skin, it is repelled by sebum and becomes unfit to the skin.

On the other hand, polyhydric alcohols such as 1,3-butylene glycol, propylene glycol, polyethylene glycol, sorbitol, and xylitol are known as humectants other than glycerin (Patent Document 2).
However, these polyhydric alcohols are less sticky than glycerin, but have a low moisturizing effect and rough skin improving effect. In addition, like glycerin, when applied to the skin, there are problems to be solved such as repelling by sebum and deterioration of the familiarity with the skin.

For the purpose of reducing the stickiness of the moisturizer, powder blending is known (Patent Document 1).
However, when blending powder, a large amount must be blended in order to produce a stickiness reducing effect. In addition, in the case of a skin external preparation having a low viscosity such as a lotion, since the powder precipitates, it must be used after shaking, which is troublesome and troublesome. Furthermore, the emulsion has a problem that the powder dissolves depending on the process and the powder swells depending on the preparation.

New Cosmetics Science Nanzan-do 144 pages JP 2002-356416 A JP 11-322575 A

  As a result of intensive studies by the present inventors to achieve the above object, when a microgel comprising a specific copolymer is used in combination with a humectant such as glycerin, the moisturizer is maintained without damaging the moisturizing effect of the moisturizing agent and the effect of improving skin roughness. It was found that the stickiness caused by the agent was remarkably improved.

  The objective of this invention is providing the skin external preparation which is excellent in a feeling of use with a moisturizing and rough skin improvement effect.

（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のアルキルを表し、Ｒ₃は炭素原子数１〜８のアルキルを表す。

（３）
Ｒ₄とＲ₅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。 That is, the present invention relates to a copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formula (2) and a crosslinkable monomer of the following formula (3), and a humectant. An external preparation for skin characterized by containing the above.

(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 alkyl having 1 to ₃ carbon atoms, and R ₃ represents alkyl having 1 to 8 carbon atoms.

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

In the present invention, the monomers (1) to (3) are radically polymerized in a water-ethanol mixed solvent under the following conditions (A), (B), (C), and (D). The present invention provides a skin external preparation characterized by blending a microgel comprising a copolymer obtained and a humectant.
(A) The hydrophobic monomer has a composition in which one or more methacrylic acid derivatives having an alkyl having 1 to 8 carbon atoms are mixed. (B) The charged amount of the polyethylene oxide macromonomer and 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 0.1 to 1.5 with respect 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).

  Furthermore, this invention provides said skin external preparation characterized by the said moisturizer being a polyhydric alcohol.

(1) The external preparation for skin of the present invention has a high moisturizing effect and also has an effect of improving skin roughness.
(2) The external preparation for skin of the present invention is excellent in use feeling. That is, it is smooth and has no stickiness. It is particularly useful for cosmetics containing glycerin where stickiness is a problem.
(3) The external preparation for skin of the present invention gives the user a superior moisturizing effect.

The present invention is described in detail below.
"Copolymer used in the present invention"
As the polyethylene oxide macromonomer of the formula (1), for example, a reagent commercially available from Aldrich or Bremer (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, Nippon Oil & Fats Blemmer (registered trademark) PME1000 or Blemmer (registered trademark) PME4000 is suitable.

As the hydrophobic monomer of the formula (2), for example, a reagent commercially available from Aldrich or Tokyo Kasei can be used. The alkyl chain of R _{3 in} formula (2) is alkyl having 1 to 8 carbon atoms. Formula (2) is methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate. Butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate and the like. In particular, methyl methacrylate, butyl methacrylate, and octyl methacrylate are suitable. These hydrophobic monomers are general-purpose raw materials and can be easily obtained as general industrial raw materials.

  The crosslinkable monomer of the formula (3) 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 (3) is preferably 1 to 3. Specifically, ethylene glycol dimethacrylate sold by Aldrich, Bremer (registered trademark) PDE-50 manufactured by NOF Corporation is suitable.

The copolymer used in the present invention is obtained by copolymerizing the above monomer by an arbitrary polymerization method, and in particular, under the conditions (A), (B) and (C) below, It is preferable that it is a copolymer (microgel) obtained by radical polymerization of the monomer (3) in a water-ethanol mixed solvent.
(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

  The charged amount of the polyethylene oxide macromonomer and the hydrophobic monomer (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 is less than 1/10 of the hydrophobic monomer by 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 charging ratio of the polyethylene oxide macromonomer and the hydrophobic monomer is preferably in the range of 1:10 to 1: 200. More preferably, it is in the range of 1:25 to 1: 100.

  By copolymerizing the crosslinkable monomer (B), a microgel in which the hydrophobic polymer in the core portion is crosslinked can be polymerized. 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 weight.

  The mixing ratio of water / ethanol which is the polymerization solvent of (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 to 60:10 to 40 (volume ratio of 20 ° C.). More preferably, it is water: ethanol = 80-70: 20-30 (20 degreeC volume ratio).

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 polymerization is performed without strictly controlling the stirring conditions.

  By the above production method, a microgel composed of monodisperse particles having a particle diameter of 50 to 300 nm and a dispersity of less than 0.01 is obtained. In addition, this microgel has the characteristic that it swells in an organic solvent.

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 ゼータサイザー４７００、ブルックヘーブン製 ゼータプラ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。 In general, 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 Zetasizer 4700, Brookhaven Zeta Plus.
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.

In addition, all the conventional microgels made of synthetic polymers are those using a polymer electrolyte 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 microgel used in the present invention is a corona-core in which hydrophilic macromonomer and hydrophobic monomer are ordered in a solvent as shown in FIG. 1, the particle diameter is substantially constant, and the core portion is crosslinked. Type polymer microgel is considered to be formed.

  The above is the description of the copolymer used in the present invention. The external preparation for skin of the present invention is produced by mixing and dispersing this copolymer in water (or an aqueous phase in which water-soluble cosmetic ingredients are dissolved) by a conventional method. That is, the external preparation for skin of the present invention is a cosmetic having an excellent commercial value that can be produced by a very simple manufacturing process.

  The microgel used in the present invention preferably has a particle size of 250 nm or less when dispersed in ion-exchanged water. When the particle diameter exceeds 250 nm, it may not be preferable as a cosmetic from the viewpoint of stability during long-term storage under high temperature conditions, or the feeling of use may not be preferred.

  The microgel used in the present invention is preferably blended in the range of usually 0.001% by mass or more based on the total amount of the external preparation for skin. When the blending amount of the microgel is less than 0.001% by mass, it is difficult to obtain an effect of improving the feeling of use.

  The microgel used in the present invention can be confirmed to reduce the characteristic stickiness of the moisturizing agent only by adding 0.001% by mass in water, and functions as a usability improving agent by mixing. In the prior art, it has been difficult to suppress the stickiness of the skin at the time of application and after drying while maintaining the moisturizing effect due to the high formulation of the moisturizing agent.

The external preparation for skin of the present invention is preferably a cosmetic containing the microgel and a humectant at the same time. This is because a cosmetic containing a moisturizing agent is very difficult to adjust the balance between the moisturizing effect and the feeling of use in the prior art, and it is difficult to produce a cosmetic that emphasizes the feeling of use.
The amount of the moisturizer is preferably 0.1% by mass or more and less than 40% by mass with respect to the total amount of the external preparation for skin.

  The humectant used in the present invention is preferably a polyhydric alcohol. In particular, glycerin is preferable, and as a humectant other than glycerin, polyethylene glycol, 1,3-butylene glycol, erythritol, dipropylene glycol, betaine, sorbitol, xylitol, maltitol, mucopolysaccharide, hyaluronic acid, chondroitin sulfate, chitin, chitosan Etc.

  The skin external preparation of the present invention can be used for skin care products, makeup products, and hair care products. In particular, it is preferably used as a skin care product, and does not stick to forms such as lotion, milky lotion, serum, cream, impregnation mask, body lotion, face wash.

  The skin external preparation of the present invention further includes a medicinal agent, a moisturizing ingredient, an anti-inflammatory agent, a bactericidal agent, an antiseptic, an ultraviolet absorber, an antioxidant, an organic and inorganic powder, which are usually used in cosmetics, pharmaceuticals, etc. A fragrance | flavor, a pigment | dye, etc. can be mix | blended as needed.

  The skin external preparation of the present invention can provide a skin external preparation excellent in moisturizing effect and usability even in a cosmetic comprising an oil and an oil-soluble drug and / or fragrance that dissolves in the oil. Also in this case, as described above, the humectant content is preferably 0.01 to less than 40% by mass with respect to the total amount of the external preparation for skin.

  The oily component to be blended in the external preparation for skin may be any of a liquid oil, a solid oil, a semi-solid oil, or a substance hardly soluble in water. For example, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, flaxseed oil, safflower oil, Cottonseed oil, evening primrose oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagiri oil, Japanese kiri oil, jojoba oil, germ oil, triglycerin, trioctanoic acid glycerin, triisopalmitic acid glycerin, etc. Liquid oil, cacao oil, coconut oil, horse fat, hydrogenated palm oil, palm oil, beef tallow, sheep fat, hydrogenated beef tallow, palm kernel oil, pork fat, beef bone fat, owl kernel oil, hydrogenated oil, cow leg fat, Solid oils and fats such as mole, hardened castor oil, beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, ibota wax, whale wax, montan wax, nukarou, Norin, cabbage wax, lanolin acetate, liquid lanolin, sugar cane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojoballow, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, lanolin fatty acid polyethylene glycol, POE hydrogenated Waxes such as lanolin alcohol ether, liquid paraffin, ozokerite, squalene, pristane, paraffin, ceresin, squalane, petrolatum, microcrystalline wax, hydrocarbons such as isopropyl myristate, octyl octoate, octyldodecyl myristate, isopropyl palmitate, Butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, dimethylo Hexyldecyl tannate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearylate, ethylene glycol di-2-ethylhexylate, dipentaerythritol fatty acid ester, N-alkyl monoisostearate Glycol, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexylate, tri Glycerin-2-ethylhexylate, trimethylolpropane triisostearate, cetyl-2-ethylhexanoate, 2-ethylhexylpa Lumitate, glyceryl trimyristate, glyceride tri-2-heptylundecanoate, castor oil fatty acid methyl ester, oleic acid oil, cetostearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, diisopropyl adipate, N-lauroyl- L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sepatate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, adipic acid 2-hexyldecyl, diisopropyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, synthetic esters, lauric acid, myristic acid, palmitic acid, Higher fatty acids such as formic acid, behenic acid (behenyl) acid, oleic acid, 12-hydroxystearic acid, undecylenic acid, tolic acid, lanolin fatty acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid, lauric alcohol, cetyl alcohol , Stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, monostearyl glycerene ether (batyl alcohol), 2-decyltetradecinol, lanolin alcohol, cholesterol, hexyldodecanol, isostearyl alcohol, octyldodecanol, etc. Linear, branched higher alcohols, silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane, perfluorodecalin, perfluoro Perfluorocarbons or perfluoropolyethers such as hexane, triperfluoro-n-butylamine, vitamin A and its derivatives, vitamin D and its derivatives, vitamin E and its derivatives, vitamins such as vitamin K and its derivatives, sterols, Natural and synthetic fragrances and the like can be mentioned. Among them, a melting point of a normal temperature or lower is distinguished from a liquid oil, and a melting point of a normal temperature or higher is distinguished from a solid or semisolid oil. Among these, it is most preferable to add a liquid polar oil.

The drug component may be any of oil-soluble, water-soluble, and amphiphilic. Specific examples include whitening agents, anti-inflammatory agents, antibacterial agents, hormone agents, vitamins, various amino acids and their derivatives, enzymes, antioxidants, hair restorers and the like.
Examples of whitening agents include hydroquinone derivatives such as arbutin, kojic acid, L-ascorbic acid (vitamin C) and derivatives thereof, pantotenyl ethyl ether, tranexamic acid and derivatives thereof, placenta extract and plant extract (eg chamomile extract), etc. Examples of these extracts are exemplified.
Examples of L-ascorbic acid derivatives include L-ascorbic acid monostearate, L-ascorbic acid monopalmitate, L-ascorbic acid monoalkyl esters such as L-ascorbic acid monooleate, L-ascorbic acid monophosphate, L L-ascorbic acid monoesters such as ascorbic acid-2-sulfate; L-ascorbic acid dialkyl esters such as L-ascorbic acid distearate, L-ascorbic acid dipalmitate, L-ascorbic acid dioleate; L-ascorbic acid dilin L-ascorbic acid diesters such as acid esters; L-ascorbic acid trialkyl esters such as L-ascorbic acid tristearate, L-ascorbic acid tripalmitate, L-ascorbic acid trioleate; - ascorbic acid triesters such as ascorbic acid triphosphate ester; and L- ascorbic acid glucosides such as L- ascorbic acid 2-glucoside and the like. Examples of L-ascorbic acid and derivatives thereof include L-ascorbic acid, L-ascorbic acid phosphate, L-ascorbic acid-2-sulfate, L-ascorbic acid 2-glucoside, or salts thereof.
Examples of the tranexamic acid derivative include a dimer of tranexamic acid (for example, trans-4- (trans-aminomethylcyclohexanecarbonyl) aminomethylcyclohexanecarboxylic acid, etc.), an ester of tranexamic acid and hydroquinone (for example, trans-4 -Aminomethylcyclohexanecarboxylic acid 4'-hydroxyphenyl ester, etc.), ester form of tranexamic acid and gentisic acid (for example, 2- (trans-4-aminomethylcyclohexylcarbonyloxy) -5-hydroxybenzoic acid and its salt, ), Amides of tranexamic acid (for example, trans-4-aminomethylcyclohexanecarboxylic acid methylamide and salts thereof, trans-4- (P-methoxybenzoyl) aminomethylcyclohexanecarboxylic acid and And salts of trans-4-guanidinomethylcyclohexanecarboxylic acid and salts thereof, and the like.
Examples of the anti-inflammatory agent include glycyrrhizin, glycyrrhizinate (eg, dipotassium glycyrrhizinate, ammonium glycyrrhizinate, etc.), allantoin and the like.
Examples of the antibacterial agent include resorcin, sulfur, salicylic acid and the like.
Examples of the hormone agent include oxytocin, corticotropin, vasopressin, secretin, gastrin, calcitonin, hinokitiol, ethinyl estradiol and the like.
Examples of vitamins include vitamin A and its derivatives (for example, retinol, vitamin A palmitate, etc.), vitamin B6, vitamin B6 derivatives such as vitamin B6 hydrochloride, nicotinic acid derivatives such as nicotinic acid and nicotinamide, vitamin E And derivatives thereof, β-carotene and the like.
Examples of various amino acids and their derivatives and enzymes include L-glutamic acid, urocanic acid, trypsin, lysozyme chloride, chymotrypsin, semi-alkaline proteinase, serrapeptase, lipase, and hyaluronidase.
Examples of the antioxidant include thiotaurine, glutathione, catechin, albumin, ferritin, metallothionein and the like.
Examples of the hair restoring agent include β-glycyrrhetinic acid, pantothenyl ethyl ether, minoxidil and the like.
Also, a refreshing agent such as camphor or menthol can be used.

  Next, an Example is given and this invention is demonstrated. The present invention is not limited to these examples. Initially, the manufacture example of the copolymer (microgel) used for the Example is shown. Unless otherwise specified, the amount is expressed in mass%.

"Examples of microgel production"
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, 50 mL of a water-ethanol mixed solvent (water: ethanol = 60: 40 volume ratio) was added to PME-4000, methyl methacrylate (MMA), butyl methacrylate (nBMA), 2- Dissolve ethylhexyl methacrylate (EHMA) and ethylene glycol dimethacrylate (EGDMA). 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.
The amount (g) of the monomer used is shown in “Table 1”.

"Measurement method of particle size and degree of dispersion"
The particle size of the microgel was measured using a Zetasizer manufactured by Malvern. 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.

"Microgel particle size and dispersity"
The particle diameter and dispersity of the obtained microgel are shown in “Table 2”.

Next, the Example which mix | blended microgel with the skin external preparation is described.
Prior to the description of the examples of the present invention, an evaluation method is shown below.
"Test method by conductance measurement"
The skin conductance before and 120 minutes after application was measured using the forearm of 10 panelists, and the moisturizing effect was evaluated from the rate of change. In addition, it is possible to examine the effect of the stratum corneum on the water absorption and water retention capacity by the skin conductance increase rate, and it can be evaluated that the greater the increase rate, the more the stratum corneum moisture increases and the higher the moisturizing effect. .

The evaluation criteria of "Evaluation (1) Test by conductance measurement" are as follows.
◎ ・ ・ ・ The average conductance increase rate of 10 panelists is 40% or more ○ ・ ・ ・ The average conductance increase rate of 10 panelists is 25% or more and less than 40% Δ ・ ・ ・ The conductance increase rate of 10 panelists The average is 10% or more and less than 25% x ... The average conductance increase rate of 10 panelists is less than 10%

"Evaluation (2): Smooth skin"
An actual use test was conducted by 10 professional panelists on the smoothness of the skin during and after use. The evaluation criteria are as follows.
◎ ... More than 8 professional panelists recognized that the skin was smooth during and after use.
○ ... 6 or more and less than 8 professional panelists recognized that the skin was smooth during use and after use.
Δ: 3 or more and less than 6 professional panelists recognized that the skin was smooth during and after use.
X: Less than 3 professional panelists recognized that the skin was smooth during use and after use.

“Evaluation (3): No stickiness on the skin”
An actual use test was conducted by 10 professional panelists on the non-stickiness of the skin during and after use. The evaluation criteria are as follows.
◎ ... More than 8 professional panelists recognized that there was no stickiness on the skin during and after use.
○ ... 6 or more professional panelists recognized that there was no stickiness on the skin during and after use.
Δ: 3 or more professional panelists recognized that there was no stickiness on the skin during and after use.
X: Less than 3 professional panelists recognized that there was no stickiness to the skin during and after use.

“Evaluation (4): Moisturizing effect”
An actual use test was conducted by 10 professional panelists for the presence or absence of a moisturizing effect after 120 minutes of use. The evaluation criteria are as follows.
◎ ・ ・ ・ 8 or more professional panelists recognized that there was a moisturizing effect.
○ ... 6 or more and less than 8 professional panelists recognized that there was a moisturizing effect.
Δ: 3 or more and less than 6 professional panelists recognized that there was a moisturizing effect.
X: Less than 3 professional panelists recognized that there was a moisturizing effect.

“Evaluation (5): Skin roughness improvement effect test”
A rough skin improvement effect test was conducted with 10 panels with rough skin on the face (part: cheek). In the test method, different lotions were applied to the left and right cheeks for one week, and the determination was made the next day after the period. The evaluation criteria are as follows.
◎ ... 8 or more panelists recognized that the rough skin was improved.
○ ... 6 or more and less than 8 panelists recognized that rough skin was improved.
Δ: 3 or more and less than 6 panelists recognized that rough skin was improved.
X: Less than 3 panelists recognized that rough skin was improved.

"Effects of microgel composition"
Evaluation as a skin external preparation was performed using the following basic composition for test.
Ion exchange water to 100% by mass
Ethyl alcohol 10
Microgel (A) of Production Example 1-7 0.1
Glycerin 8.0
Citric acid Appropriate amount Sodium citrate Appropriate amount Sodium hexametaphosphate Appropriate amount Phenoxyethanol Appropriate amount Fragrance Appropriate amount

(A)

  As shown in Table 3, the external preparation for skin containing copolymers of various compositions is excellent in all of conductance measurement, smoothness, stickiness, moisturizing effect, and rough skin improvement effect.

"Effects of microgel content"
Evaluation as a skin external preparation was performed using the following basic composition for test.
Ion exchange water to 100% by mass
Ethyl alcohol 10
Microgel of Production Example 4 (B)
Glycerin 8.0
Citric acid Appropriate amount Sodium citrate Appropriate amount Sodium hexametaphosphate Appropriate amount Phenoxyethanol Appropriate amount Fragrance Appropriate amount

(B)

  As shown in Table 4 above, the blending amount of the copolymer in the external preparation for skin is preferably 0.01 to 20% by mass, particularly preferably 0.1 to 1.0% by mass.

"Effects of humectant content"
Evaluation as a skin external preparation was performed using the following basic composition for test.
Ion exchange water to 100% by mass
Ethyl alcohol 10
Microgel of Production Example 4 0.1
Moisturizer (C)
Citric acid (food) Appropriate amount Sodium citrate Appropriate amount Sodium hexametaphosphate Appropriate amount Phenoxyethanol Appropriate amount Fragrance Appropriate amount

(C)

  As shown in Table 5 above, the content of the humectant is preferably 0.1 to 30% by mass, and particularly preferably 1 to 15% by mass.

The following are other skin external preparations of the present invention.
INDUSTRIAL APPLICABILITY The present invention can provide an excellent skin external preparation even in cosmetics containing a cosmetic raw material oil and further containing an oil-soluble drug and / or a fragrance.

"Example 22 Latex"
Microgel of Production Example 1 1.0
Dimethylpolysiloxane 3.0
Decamethylcyclopentasiloxane 4.0
Ethyl alcohol 5.0
Glycerin 6.0
1,3-butylene glycol 5.0
Polyoxyethylene methyl glucoside 3.0
POE (14) POP (7) Dimethyl ether 1.0
Ascorbic acid glucoside 2.0
Sunflower oil 1.0
Squalane 2.0
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
Carboxyvinyl polymer 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 23 moisturizing cream"
Microgel of Production Example 5 2.0
α-Olefin oligomer 10
Vaseline 1.0
Microcrystalline wax 3.0
Decamethylcyclopentasiloxane 5.0
Glycerin 10
Dipropylene glycol 2.0
1,3-butylene glycol 2.0
Erythritol 2.0
Squalane 1.0
POE (17) POP (4) Dimethyl ether 2.0
Glycerin fatty acid ester eicosannic acid condensate 0.1
Isostearic acid 1.0
Cetyl 2-ethylhexanoate 5.0
Sodium chloride 0.5
Sodium hexametaphosphate 0.05
Stearyl glycyrrhetinate 0.05
Koubo extract 0.1
L-ascorbyl magnesium phosphate 2.0
Tocopherol acetate 0.5
Thiotaurine 0.1
DL-pyrrolidonecarboxylate sodium 1.0
Turmeric extract 0.1
Edetate trisodium 0.1
Dimethyl distearyl ammonium hectorite 2.0
Sodium carboxymethylcellulose 0.1
Paraben Suitable amount Purified water Residual flavor

"Example 24 Eye cream"
Microgel of Production Example 5 1.0
Decamethylcyclopentasiloxane 15
Trimethylsiloxysilicate-octamethylcyclotetrasiloxane
7.5
Polyoxyethylene / methylpolysiloxane copolymer 2.0
Glycerin 15
1,3-butylene glycol 3.0
Maltitol solution 2.0
Macadamia nut oil 0.5
Squalane 1.0
Cholesteryl hydroxystearate 0.1
Cetyl 2-ethylhexanoate 2.0
Distearyldimethylammonium chloride 0.2
L-ascorbic acid sulfate disodium 0.01
DL-α-tocopherol 2-L-ascorbic acid diester
0.02
DL-α-tocopherol acetate 0.05
Succinyl atelocollagen solution 0.4
Sodium hyaluronate 0.002
p-Oxybenzoate ester 0.15
Edetic acid 3Na 0.02
Diparamethoxycinnamic acid mono-2-ethylhexanoate glyceryl 0.02
Aluminum magnesium silicate 0.3
Purified water residue

“Example 25 Daytime serum”
Microgel of Production Example 2 0.5
Dimethylpolysiloxane 5.0
Decamethylcyclopentasiloxane 25
Trimethylsiloxysilicate 5.0
Polyoxyethylene / methylpolysiloxane copolymer 2.0
Dipropylene glycol 5.0
Fine zinc oxide 15
Paraben Appropriate amount Phenoxyethanol Appropriate amount Trisodium edetate Appropriate amount Arbutin 3.0
2-Ethylhexyl paramethoxycinnamate 7.5
Dimethyl distearyl ammonium hectorite 0.5
Spherical polyalkyl acrylate powder 5.0
Purified water Residual fragrance Appropriate amount

"Example 26 impregnation mask"
Microgel of Production Example 1 0.1
Glycerin 1.0
1,3-butylene glycol 8.0
Xylit 2.0
Polyethylene glycol 1500 2.0
Rosemary oil 0.01
Sage oil 0.1
Citric acid 0.02
Sodium citrate 0.08
Sodium hexametaphosphate 0.01
Hydroxypropyl-β-cyclodextrin 0.1
Tranexamic acid 2.0
Vitamin E acetate 1.0
Aloe extract 0.1
Birch extract 0.1
Lavender oil 0.01
Xanthan gum 0.05
Carboxyvinyl polymer 0.15
P-Hydroxybenzoate appropriate amount purified water remaining

"Example 27 Thorough lotion"
Microgel of Production Example 4 0.8
Glycerin 1.0
Dipropylene glycol 12
Ethanol 8.0
POE methyl glucoside 3.0
POE (24) POP (13) Decyl tetradecyl ether 0.5
Citric acid 0.02
Sodium citrate 0.08
Hydroxypropyl-β-cyclodextrin 0.5
Thiotaurine 0.1
Adenosine triphosphate-2sodium 0.1
Sodium chondroitin sulfate 0.01
EDTA 3 sodium 0.01
Hydroxyethyl cellulose 0.1
Potassium hydroxide 0.2
Paraben Suitable amount Purified water Residual flavor

"Example 28 Conditioner"
Microgel of Production Example 7 5.0
Dimethylpolysiloxane 2.0
Stearyl alcohol 2.0
Behenyl alcohol 1.0
Glycerin 1.5
Octyl palmitate 1.0
Polyoxyethylene stearyl ether 0.2
Citric acid 0.05
Paraoxybenzoic acid ester Appropriate amount Phenoxyethanol Appropriate amount Hydroxyethylcellulose 0.1
Stearyltrimethylammonium chloride 1
Highly polymerized methylpolysiloxane 1.5
Purified water Residual fragrance Appropriate amount

"Example 28 cream foundation"
Microgel of Production Example 3 0.1
Behenyl alcohol 0.5
Dipropylene glycol 6.0
Stearic acid 1.0
Glycerol monostearate1.0
Potassium hydroxide 0.2
Triethanolamine 0.8
DL-α-tocopherol acetate 0.1
P-Hydroxybenzoate appropriate amount yellow iron oxide 1.0
α-Olefin oligomer 3.0
Dimethylpolysiloxane (6 mPa.s) 2.0
Dimethylpolysiloxane (100 mPa.s) 5.0
Batyl alcohol 0.5
Isostearic acid 1.0
Behenic acid 0.5
Cetyl 2-ethylhexanoate 10
Polyoxyethylene glycerol monostearate1.0
Titanium oxide 3.0
Mica titanium / polyalkyl acrylate composite powder 0.5
Surface-treated titanium oxide (MT-062) 10
Polyacrylic acid-coated mica titanium 0.5
Black iron oxide coated mica titanium 0.5
Silica anhydride 6.0
2-Ethylhexyl paramethoxycinnamate 2.0
Bengala Appropriate amount of blue, appropriate amount of black iron oxide
Bentonite 1
Sodium carboxymethylcellulose 0.1
Purified water Residual fragrance Appropriate amount

"Example 29 body shampoo"
Microgel of Production Example 4 0.5
Ethanol 10
Glycerin 1.0
Orange oil 0.05
Rosemary oil 0.05
Polyoxyethylene stearyl ether 0.5
Coconut oil fatty acid acyl-potassium glutamate mixed solution 10
Palm oil fatty acid methyl taurine sodium 5.0
2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine
1.5
Sodium hyaluronate 0.05
Citric acid 0.1
Sodium citrate 0.2
Dipotassium glycyrrhizinate 0.1
Ethylenediamine hydroxyethyl triacetate trisodium xanthan gum 0.5
Purified water residue

ADVANTAGE OF THE INVENTION According to this invention, it can provide the skin external preparation which has a moisturizing effect and a rough skin improvement effect, and was excellent in the usability | use_condition.
When the external preparation for skin of the present invention is a cosmetic, it is a useful cosmetic that can appeal the impression of the cosmetic effect to the user very effectively from its excellent feeling of use.

It is a schematic diagram which shows the core corona type polymer nanosphere production | generation mechanism of the microgel used for this invention.

Claims (3)

It contains a copolymer obtained by polymerizing a polyethylene oxide macromonomer of the following formula (1), a hydrophobic monomer of the following formula (2) and a crosslinkable monomer of the following formula (3), and a humectant. A topical skin preparation.

(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 alkyl having 1 to ₃ carbon atoms, and R ₃ represents alkyl having 1 to 8 carbon atoms.

(3)
R ₄ and R ₅ each independently represents alkyl having 1 to 3 carbon atoms, and m is a number from 0 to 2. From a copolymer obtained by radical polymerization of the monomers (1) to (3) in a water-ethanol mixed solvent under the following conditions (A), (B), (C) and (D): The skin external preparation characterized by mix | blending this microgel and a moisturizer.
(A) The hydrophobic monomer has a composition in which one or more methacrylic acid derivatives having an alkyl having 1 to 8 carbon atoms are mixed. (B) The charged amount of the polyethylene oxide macromonomer and 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 0.1 to 1.5 with respect 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 skin external preparation according to claim 1 or 2, wherein the humectant is a polyhydric alcohol.

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