JP2014034545A - External preparation for skin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an external preparation for skin having both an excellent use feeling and a skin barrier improving action without creakiness in use, and a tight feeling after use.SOLUTION: An external preparation for skin contains a co-polymer that essentially consists of: a constitutional unit derived from an acrylic monomer including a saccharide side chain; and a constitutional unit derived from an acrylic monomer including a constitutional unit derived from an acrylic monomer including a hydrophobic and specific branch structure. Preferably, the co-polymer includes a constitutional unit derived from a specific structure hydrophilic acrylic monomer.

Description

The present invention relates to an external preparation for skin, and more particularly, to an external preparation for skin having excellent skin barrier function improving action and excellent usability.

  The main role of the human stratum corneum is to suppress the transpiration of moisture from the inside of the skin, to retain moisture inside the skin, to moisturize the skin, to prevent the entry of irritants into the skin from the outside, and to the skin It acts as a so-called skin barrier, such as protecting the inside from external stimuli. However, in recent years, the chance of contact with various chemical substances has increased, and the barrier function of the stratum corneum has decreased due to such external factors and internal factors such as stress.

Under such circumstances, cosmetics, particularly skin care products, are required to have an effect of improving the barrier function of the reduced stratum corneum. As such means, a water-soluble polymer is blended in the cosmetic, Attempts have been made to form a film on the skin and to supplement the reduced barrier function of the stratum corneum with this film. As such a polymer, a polymer having a side chain structure excellent in affinity with the skin is preferable, and a polymer having a sugar structure in the side chain is frequently used. (For example, see Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5)

However, cosmetics containing these polymers are excellent in the action of improving the barrier of the stratum corneum, but feel the squeaks peculiar to water-soluble polymers during use, and the skin is stretched due to the low flexibility of the film. There are cases where there is a problem in the feeling of use such as the feeling after use.
That is, it has been desired to develop an external preparation for skin that has a good feeling of use and is excellent in improving the skin barrier function.

  On the other hand, a copolymer comprising an acrylic monomer having a sugar side chain and an acrylic monomer having an alkyl group having a specific branched structure forms a film having a low friction coefficient on the skin and excellent flexibility, and further It has not been known that the skin external preparation contained has both excellent use feeling and excellent skin barrier improving action without creaking during use and feeling of tension after use.

JP 2005-8592 A JP 2004-18490 A JP 2004-196666 A JP 2007-153811 A JP 2007-308382 A

  The objective of this invention is providing the skin external preparation excellent in the skin barrier improvement effect | action and a usability | use_condition.

（Ｉ）

（一般式（Ｉ）中Ｒ^１は水素原子またはメチル基を、Ｇ−Ｏ−は還元糖の１位の水酸基より水素を除いた基を表す。ｎは２又は３を、ｍは１〜５の整数を表す。）
一般式（ＩＩ）

（ＩＩ）

（一般式（ＩＩ）中Ｒ^２は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^３は環構造を含まない、炭素数１３〜３０の分岐状炭化水素基、または、環構造を含まない、２つ以上の分岐を有する炭素数６〜１２の炭化水素基を表す。）
（２）さらに、コポリマーが、重合性カルボン酸及びその塩、下記一般式（ＩＩＩ）で表される親水性モノマーからなる群より選択される一種又は二種以上のモノマーから誘導される構成単位を含有することを特徴とする（１）記載の皮膚外用剤。
一般式（ＩＩＩ）

（ＩＩＩ）

（一般式（ＩＩＩ）中Ｒ^４は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^５は水酸基を有していてもよい炭素数２〜４のアルキレン基を表し、Ｒ^６は水素原子、炭素数６〜１０の芳香族炭化水素基、炭素数１〜１４の脂肪族炭化水素基又は炭素数１〜１２のアシル基を表す。ｐは４〜４０の整数を表す。）
（３）一般式（ＩＩＩ）で表される親水性モノマーが、下記一般式（ＩＶ）で表される親水性モノマーであることを特徴とする（２）に記載の皮膚外用剤。
一般式（ＩＶ）

（ＩＶ）

（一般式（ＩＶ）中Ｒ^７は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^８は水素原子、炭素数６〜１０の芳香族炭化水素基、炭素数１〜１４の脂肪族炭化水素基又は炭素数１〜１２のアシル基を表す。ｑは４〜４０の整数を表す。）
（４）重合性カルボン酸がアクリル酸及び／またはメタクリル酸であることを特徴とする（２）又は（３）に記載の皮膚外用剤。
（５）コポリマーを皮膚外用剤全量の０．５〜２５質量％含有することを特徴とする（１）〜（４）の何れかに記載の皮膚外用剤。
（６）化粧料であることを特徴とする（１）〜（５）の何れかに記載の皮膚外用剤。
In view of such a situation, the present inventors have intensively studied for a skin external preparation excellent in skin barrier improving action and usability, and as a result, a structural unit derived from an acrylic monomer having a sugar side chain, hydrophobicity The topical skin preparation containing a copolymer containing a structural unit derived from an acrylic monomer having a specific branched structure as an essential structural unit has been found to solve the problem, and the present invention has been achieved. That is, the present invention is as follows.
(1) One or more structural units derived from the monomer represented by the following general formula (I) and one or more structural units derived from the hydrophobic monomer represented by the general formula (II) A skin external preparation comprising a copolymer having a structural unit as an essential structural unit.
Formula (I)

(I)

(In general formula (I), R ¹ represents a hydrogen atom or a methyl group, G—O— represents a group in which hydrogen is removed from the hydroxyl group at the 1-position of the reducing sugar, n is 2 or 3, and m is 1 to 5). Represents an integer.)
Formula (II)

(II)

(In General Formula (II), R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ³ represents a branched hydrocarbon group having 13 to ³⁰ carbon atoms or a ring structure that does not include a ring structure. (A hydrocarbon group having 6 to 12 carbon atoms having two or more branches not included)
(2) Further, the copolymer is a structural unit derived from one or more monomers selected from the group consisting of a polymerizable carboxylic acid and a salt thereof, and a hydrophilic monomer represented by the following general formula (III). The skin external preparation as described in (1) characterized by containing.
Formula (III)

(III)

(In general formula (III), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁵ represents an alkylene group having 2 to 4 carbon atoms which may have a hydroxyl group, and R ⁶ represents hydrogen. An atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an acyl group having 1 to 12 carbon atoms, p represents an integer of 4 to 40.)
(3) The external preparation for skin according to (2), wherein the hydrophilic monomer represented by the general formula (III) is a hydrophilic monomer represented by the following general formula (IV).
Formula (IV)

(IV)

(In general formula (IV), R ⁷ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁸ represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or an aliphatic group having 1 to 14 carbon atoms. And represents a hydrocarbon group or an acyl group having 1 to 12 carbon atoms, q represents an integer of 4 to 40.)
(4) The external preparation for skin according to (2) or (3), wherein the polymerizable carboxylic acid is acrylic acid and / or methacrylic acid.
(5) The skin external preparation according to any one of (1) to (4), wherein the copolymer is contained in an amount of 0.5 to 25% by mass based on the total amount of the external preparation for skin.
(6) The external preparation for skin according to any one of (1) to (5), which is a cosmetic.

ADVANTAGE OF THE INVENTION According to this invention, the skin external preparation excellent in the skin barrier improvement effect | action and usability | use_condition can be provided.

（Ｉ）

（一般式（Ｉ）中Ｒ^１は水素原子またはメチル基を、Ｇ−Ｏ−は還元糖の１位の水酸基より水素を除いた基を表す。ｎは２又は３を、ｍは１〜５の整数を表す。） Hereinafter, the present invention will be described in detail.
<1> A structural unit derived from a monomer having a sugar residue constituting a copolymer which is an essential component of the external preparation of the present invention. An essential component of the external preparation of the present invention (hereinafter simply referred to as a copolymer of the present invention). May contain a structural unit derived from a monomer having a sugar residue represented by the following general formula (I) as an essential structural unit. In the present invention, the “structural unit derived from a monomer” refers to a structural unit formed by cleavage of a carbon-carbon unsaturated bond of a corresponding monomer by a polymerization reaction.
Formula (I)

(I)

(In general formula (I), R ¹ represents a hydrogen atom or a methyl group, G—O— represents a group in which hydrogen is removed from the hydroxyl group at the 1-position of the reducing sugar, n is 2 or 3, and m is 1 to 5). Represents an integer.)

In the monomer of the general formula (I), as the reducing sugar of the group obtained by removing hydrogen from the hydroxyl group at the 1-position of the reducing sugar represented by G-O-, specifically, glucose, mannose, galactose, arabinose, xylose And one or more selected from the group consisting of monosaccharides such as ribose, disaccharides such as maltose, lactose and cellobiose, trisaccharides such as maltotriose, and oligosaccharides such as maltooligosaccharide, 1 type, or 2 or more types selected from the group consisting of glucose, galactose, arabinose, xylose, ribose, maltose, and lactose cellobiose are preferable, and glucose is particularly preferable. The monomer represented by the general formula (I) is preferably glucosyloxyethyl methacrylate (hereinafter abbreviated as GEMA) or glucosyloxyethyl acrylate (hereinafter abbreviated as GEA).

The proportion of the structural unit derived from the monomer represented by formula (I) in the copolymer of the present invention in the total structural unit is preferably 5 to 90% by mass, more preferably 10 to 85% by mass. . Below the lower limit, the film formed by the external preparation for skin containing the copolymer may have a low affinity with the skin, which is not preferable. On the other hand, if the amount is not less than the upper limit, the external preparation for skin containing the obtained copolymer may be squeezed at the time of use and may cause a feeling of tension.

（ＩＩ）

（一般式（ＩＩ）中Ｒ^２は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^３は、環構造を含まない、炭素数１３〜３０の分岐状炭化水素基、または、環構造を含まない、２つ以上の分岐を有する炭素数６〜１２の炭化水素基を表す。） <2> A structural unit derived from a hydrophobic monomer constituting a copolymer which is an essential component of the external preparation for skin of the present invention.
The copolymer that is an essential component of the external preparation for skin of the present invention is a structural unit derived from a hydrophobic monomer represented by the following general formula (II) (hereinafter, simply referred to as “structural unit II”) or Contains two or more as essential constituent units.
Formula (II)

(II)

(In General Formula (II), R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ³ represents a branched hydrocarbon group having 13 to 30 carbon atoms that does not include a ring structure, or a ring structure. Represents a C6-C12 hydrocarbon group having two or more branches.

Here, examples of the alkyl group represented by R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a cyclopropyl group. In the present invention, R ² is preferably a hydrogen atom or a methyl group.

Examples of the branched hydrocarbon group having 13 to 30 carbon atoms that does not include a ring structure represented by R ³ include 1-methyldodecanyl group, 11-methyldodecanyl group, and 3-ethylundecanyl group. 3-ethyl-4,5,6-trimethyloctyl group, 1-methyltridecanyl group, 1-hexyloctyl group, 2-butyldecanyl group, 2-hexyloctyl group, 4-ethyl-1-isobutyloctyl group, 1-methylpentadecanyl group, 2-hexyldecanyl group, 2-octyldecanyl group, 2-hexyldecanyl group, 16-methylheptadecanyl group, 9-methylheptadecanyl group, 7-methyl-2 -(3-methylhexyl) decanyl group, 3,7,11,15-tetra-methylhexadecanyl group, 2-octyldodecanyl group, 2-decyltetradecanyl group, 2-dodecylhexyl It can be exemplified decanyl group.

Moreover, as a C6-C12 hydrocarbon group which does not contain the ring structure represented by R ³ and has two or more branches, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3 , 3-dimethylbutyl group, 1,3-dimethylbutyl group, 1,2,2-trimethylpropyl group, 1,1-dimethylpentanyl group, 1-isopropylbutyl group, 1-isopropyl-2-methylpropyl group, 1,1-diethylpropyl group, 1-ethyl-1-isopropylpropyl group, 2-ethyl-4-methylpentyl group, 1-propyl-2,2-dimethylpropyl group, 1,1,2-trimethyl-pentyl group 1-isopropyl-3-methylbutyl group, 1,2-dimethyl-1-ethylbutyl group, 1,3-dimethyl-1-ethylbutyl group, 1-ethyl-1-isopropyl-propyl group, 1,1-dimethylhexyl group, 1-methyl-1-ethylpentyl group, 1-methyl-1-propylbutyl group, 1,4-dimethylhexyl group, 1-ethyl-3-methylpentyl group, 1,5- Dimethylhexyl group, 1-ethyl-6-methylheptyl group, 1,1,3,3-tetramethylbutyl group, 1,2-dimethyl-1-isopropylpropyl group, 3-methyl-1- (2,2- Dimethylethyl) butyl group, 1-isopropylhexyl group (C9), 3.5.5-trimethylhexyl group, 2-isopropyl-5-methylhexyl group, 1,5-dimethyl-1-ethylhexyl group, 3,7- Examples include dimethyloctyl group, 2,4,5-trimethylheptyl group, 2,4,6-trimethylheptyl group, 3,5-dimethyl-1- (2,2-dimethylethyl) hexyl Rukoto can.

  The constitutional unit II contained in the copolymer of the present invention may be only one type, but may contain two or more constitutional units II in combination as long as the general formula (II) is satisfied. The proportion of the structural unit II in all the structural units in the copolymer of the present invention is preferably 1 to 40% by mass, more preferably 5 to 35% by mass. Below the lower limit, the resulting external preparation for skin containing the copolymer may be squeezed at the time of use and may cause a tight feeling, which is not preferable. On the other hand, if it exceeds the upper limit, the solubility of the resulting copolymer in the external preparation for skin, particularly in water, may be lowered, which is not preferable.

The monomer represented by the general formula (II) can be easily synthesized by an esterification reaction between the corresponding alcohol and (meth) acrylic acid, (meth) acrylic anhydride or (meth) acrylic acid chloride. is there. Hereinafter, production examples of the hydrophobic monomer represented by the general formula (II) will be shown.

（Ｖ）
<Production Example 1>
In a reaction vessel equipped with a stirrer, 20.4 g (0.2 mol) of 3,3-dimethyl-2-butanol (manufactured by Tokyo Chemical Industry Co., Ltd.) and 50.0 g of triethylamine were dissolved in 500 ml of tetrahydrofuran. While the resulting solution was ice-cooled and stirred, a solution prepared by dissolving 18.1 g of acrylic acid chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) in 100 ml of tetrahydrofuran was added dropwise over 2 hours as an acid chloride. After completion of the dropwise addition, the produced white precipitate was filtered, and tetrahydrofuran and triethylamine were removed from the filtrate using a rotary evaporator to obtain a product. NMR measurement confirmed that the obtained compound was 1,2,2-trimethylpropyl acrylate represented by the general formula (V).
General formula (V)

(V)

<Production Examples 2-6>
A hydrophobic monomer represented by the general formula (II) was prepared in the same manner as in Production Example 1 except that the alcohol and acid chloride in Production Example 1 were changed as shown in Table 1. The obtained hydrophobic monomers are shown in Table 1 and general formulas (VI) to (X).

＊ １）東京化成工業（株）製
＊ ２）東京化成工業（株）製
＊ ３）「ノナノール」協和発酵ケミカル（株）製
＊ ４）東京化成工業（株）製
＊ ５）「リソノール１６ＳＰ」高級アルコール工業（株）製
＊ ６）「ファインオキソコール（登録商標） １８０」日産化学工業（株）製

* 1) Tokyo Chemical Industry Co., Ltd. * 2) Tokyo Chemical Industry Co., Ltd. * 3) "Nonanol" Kyowa Hakko Chemical Co., Ltd. * 4) Tokyo Chemical Industry Co., Ltd. * 5) "Risonol 16SP" 6) “Fine Oxocol (registered trademark) 180” manufactured by Nissan Chemical Industries, Ltd.

（ＶＩ）
Compound of Preparation Example 2 (VI)

(VI)

（ＶＩＩ）
Compound of Production Example 3 (VII)

(VII)

（ＶＩＩＩ）
Compound of Production Example 4 (VIII)

(VIII)

（ＩＸ）
Compound of Production Example 5 (IX)

(IX)

（Ｘ）
Compound of Production Example 6 (X)

(X)

（ＩＩＩ）

（一般式（ＩＩＩ）中Ｒ^４は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^５は水酸基を有していてもよい炭素数２〜４のアルキレン基を表し、Ｒ^６は水素原子、炭素数６〜１０の芳香族炭化水素基、炭素数１〜１４の脂肪族炭化水素基又は炭素数１〜１２のアシル基を表す。ｐは４〜４０の整数を表す。） <3> A structural unit derived from a hydrophilic monomer constituting the copolymer of the present invention.
The copolymer of the present invention contains a structural unit derived from the monomer represented by the general formula (I) and a structural unit derived from the monomer represented by the general formula (II) as essential structural units. Depending on the above, other structural units may be contained. Such a structural unit is selected from the group consisting of a polymerizable carboxylic acid, a salt thereof, or a monomer represented by the following general formula (III) in order to improve the solubility of the copolymer, particularly the solubility in water. One or more structural units derived from a hydrophilic monomer are preferred. (Hereinafter, the structural unit derived from the hydrophilic monomer selected from the group consisting of the monomer represented by the general formula (III) may be simply referred to as the structural unit III.)
Formula (III)

(III)

(In general formula (III), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁵ represents an alkylene group having 2 to 4 carbon atoms which may have a hydroxyl group, and R ⁶ represents hydrogen. An atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an acyl group having 1 to 12 carbon atoms, p represents an integer of 4 to 40.)

  Specific examples of the polymerizable carboxylic acid or its salt include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid and its sodium salt, potassium salt, ammonium salt, amine salt and the like. Among these, acrylic acid, methacrylic acid and salts thereof are particularly preferable because of high polymerizability. When a structural unit derived from a salt of a polymerizable carboxylic acid is introduced into the copolymer of the present invention, the polymerizable carboxylic acid may be converted into a salt in advance, and a polymerization reaction may be performed. The structural unit derived from may be derived into a copolymer and then neutralized with a base to form a salt.

Examples of the alkyl group represented by R ⁴ in the general formula (III) include a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, and a cyclopropyl group. In the present invention, R ⁴ is preferably a hydrogen atom or a methyl group.

Examples of the alkylene group represented by R ⁵ include an ethylene group, a propylene group, an isopropylene group, a 2-hydroxypropylene group, a 1-hydroxy-2-methylethylene group, and a 2-hydroxy-1-methylethylene group. Of these, ethylene group or propylene group is preferable, and ethylene group is more preferable.

Among the groups represented by R ⁶ , examples of the aromatic group having 6 to 10 carbon atoms include a phenyl group, a benzyl group, a methylphenyl group, and an ethylphenyl group; an aliphatic group having 1 to 14 carbon atoms Preferred examples of the hydrocarbon group include a methyl group, an ethyl group, a butyl group, a tertiary butyl group, a hexyl group, a cyclohexyl group, an octyl group, a 2-ethylhexyl group, and a lauryl group; Preferable examples of the ˜12 acyl group include a formyl group, an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, and a lauroyl group. Among these, the group represented by R ⁵ is preferably an aliphatic hydrocarbon group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.

Furthermore, it is important that p in the general formula (III) is in a numerical range of 4 to 40. In the present invention, by introducing the structural unit II in which n is in the above range into the copolymer, the solubility of the external preparation for skin, particularly water, can be improved. When p is less than 4, it may not be possible to improve the solubility of the obtained copolymer in the external preparation for skin, particularly water, which is not preferable. On the other hand, if p is more than 40, it is not preferable because squeeze during use of the external preparation for skin may increase.

Among the monomers represented by the general formula (III), specific examples of the monomer in which R ⁵ is a propylene group include polypropylene glycol (6) monoacrylate, polypropylene glycol (9) monoacrylate, and polypropylene glycol (13) mono Examples thereof include acrylate, polypropylene glycol (9) monomethacrylate, polypropylene glycol (13) monomethacrylate and the like. The numbers in parentheses represent the value of p. Many of these polymers are commercially available. Specific examples of these commercially available products include “Blemmer” AP-400, AP-550, AP-800, PP-500, PP-800 (all manufactured by NOF Corporation) and the like. A specific example of the monomer in which R ⁵ is an ethylene group will be described later.

（ＩＶ）

（一般式（ＩＶ）中Ｒ^７は水素原子または炭素数１〜３のアルキル基を表し、Ｒ^８は水素原子、炭素数６〜１０の芳香族炭化水素基、炭素数１〜１４の脂肪族炭化水素基又は炭素数１〜１２のアシル基を表す。ｑは４〜４０の整数を表す。） Among the structural units derived from the hydrophilic monomer represented by the general formula (III), structural units derived from the hydrophilic monomer represented by the following general formula (IV) are particularly preferable.
Formula (IV)

(IV)

(In general formula (IV), R ⁷ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁸ represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or an aliphatic group having 1 to 14 carbon atoms. And represents a hydrocarbon group or an acyl group having 1 to 12 carbon atoms, q represents an integer of 4 to 40.)

  Specific examples of the monomer represented by the general formula (IV) include polyethylene glycol (10) monoacrylate, polyethylene glycol (8) monomethacrylate, methoxypolyethylene glycol (9) acrylate, methoxypolyethylene glycol (4 ) Methacrylate, methoxypolyethylene glycol (8) methacrylate, methoxypolyethylene glycol (9) methacrylate, methoxypolyethylene glycol (23) methacrylate, oleyloxypolyethylene glycol (18) methacrylate, lauroxypolyethylene glycol (4) acrylate, lauroxypolyethylene glycol ( 18) Acrylate, Lauroxy polyethylene glycol (4) Methacrylate, Lauroyloxy polyethylene glycol Call (10) methacrylate, stearoxypolyethylene polyethylene glycol (4) methacrylate, stearoxypolyethylene polyethylene glycol (9) methacrylate, stearoxypolyethylene polyethylene glycol (30) methacrylate, nonyl phenoxy polyethylene glycol (30) monoacrylate, and the like. The numbers in parentheses indicate the value of q.

As described in the general formula (III), in the general formula (IV) as well, the components of the external preparation for skin, particularly the solubility in water, are improved, and the squeaky when using the external preparation for skin is used. In order to suppress this, it is important that q is in the numerical range of 4 to 40.

These hydrophilic monomers can be obtained in high yield by an esterification reaction between the corresponding polyethylene glycol, polyethylene glycol monoether, polyethylene glycol monoester and acrylic acid, methacrylic acid chloride or anhydride. Moreover, since there are already many commercial products, it is also possible to use such commercial products. Specific examples of such commercially available products include Blemmer, AE-400, PE-350, AME-400, PME-200, PME-350, PME-400, PME-1000, ALE-200, and ALE-. Examples include 800, PLE-200, PSE-200, PSE-400, PSE-1300, ANE-1300, etc. (all manufactured by NOF Corporation).

The structural unit derived from the hydrophilic monomer contained in the copolymer of the present invention may be only one type, but may contain two or more types of structural units in combination as long as the above-mentioned conditions are satisfied.

  When the copolymer of the present invention contains a structural unit derived from a hydrophilic monomer, the proportion of the structural unit in all the structural units is preferably 50% by mass or less. If the content exceeds 50% by mass, the resulting external preparation for skin containing the copolymer may be squeezed at the time of use and may cause a feeling of tightness.

<4> Other Arbitrary Units that may be Included in the Copolymer of the Present Invention The copolymer of the present invention is a common copolymer other than the above-mentioned essential structural unit I, essential structural unit II, and structural units derived from hydrophilic monomers. A structural unit derived from a monomer used in the coalescence can be included as an arbitrary structural unit within a range not impairing the effects of the invention. Examples of such optional structural units include acrylic acid amide, methacrylic acid amide, acrylic acid monoalkylamide, (meth) acrylic acid amide such as methacrylic acid monoalkylamide, methyl (meth) acrylate, ethyl (meth) acrylate, (Meth) acrylic acid-n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-tert-butyl, (meth) acrylic acid-n-octyl, (meth) acrylic acid-2 ethylhexyl, methacrylic acid-n -Cyclic (meth) acrylic acid such as (meth) acrylic acid alkyl ester and (meth) acrylic acid cyclohexyl not included in the hydrophobic monomer represented by the general formula (II) such as dodecyl, stearyl (meth) acrylate, etc. Alkyl ester; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl ( (Meth) acrylate, hydroxyalkyl ester of (meth) acrylic acid such as 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid aryl ester such as benzyl (meth) acrylate, methoxymethyl (meth) acrylate, (meth) Examples include structural units derived from monomers such as (meth) acrylic acid alkoxyalkyl esters such as methoxyethyl acrylate, vinyl acetate, vinylpyrrolidone, styrene, α-methylstyrene; acrylonitrile. Most of these monomers are commercially available.

<5> Copolymer of the Present Invention The copolymer of the present invention comprises the structural unit I, the structural unit II, and, if necessary, a structural unit derived from a hydrophilic monomer and an arbitrary structural unit in its skeleton. It is a copolymer to contain. Further, the copolymer of the present invention is usually a random copolymer in which structural units are randomly bonded, but may be a block copolymer or a graft copolymer.

The method for producing the copolymer of the present invention is not particularly limited. For example, the copolymer can be obtained by a method in which monomers for deriving each structural unit are mixed in a solvent and a polymerization reaction is carried out according to a method usually used in the polymerization of acrylic monomers.

The copolymer of the present invention is preferably water-soluble because it can be easily contained in an external preparation for skin. The water-soluble copolymer here is defined as a copolymer having a transmittance of 90% or more of a 20% by mass aqueous solution of the copolymer at 25 ° C. In order to obtain such a polymer, among the above polymerization methods, a polymerization method in which the monomer mixture is radically polymerized in a mixed solvent of an aqueous solution and an aqueous solvent mixed with water at an arbitrary ratio at 25 ° C. is particularly preferable. . Moreover, since the amount of residual monomer after the polymerization reaction is small, a polymerization method using a buffer solution instead of water is more preferable. The aqueous solution having a buffering action used in this method is not particularly limited as long as it is a commonly used buffer solution. Specifically, potassium chloride-hydrochloric acid solution, potassium hydrogen phthalate-hydrochloric acid solution, dihydrogen phosphate Examples thereof include potassium-disodium hydrogen phosphate solution, potassium hydrogen citrate-citric acid solution, and sodium carbonate-sodium hydrogen carbonate solution. Alternatively, an aqueous solution of salts, acids, or bases that forms a buffer solution with the ions of the initiator may be used to form a buffer solution when the initiator is added. Furthermore, as an aqueous solvent mixed with water at an arbitrary ratio at 25 ° C. used in this method, specifically, alcohols having 1 to 3 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol and isopropyl alcohol, acetone Examples thereof include ketones such as methyl ethyl ketone, diols such as ethylene glycol, polyethylene glycol, propylene glycol and 1,3 butylene glycol, ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, and tetrahydrofuran. Among these aqueous solvents, alcohols having 1 to 3 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, and isopropyl alcohol are particularly preferable because the polymerization reaction easily proceeds.

Hereinafter, production examples of the copolymer of the present invention and the copolymer of the comparative example will be shown.
<Production Example 7>
In a flask equipped with a nitrogen introduction tube, a condenser and a stirring device, 96.0 g of GEMA, 24.0 g of the hydrophobic monomer of Production Example 5, 300 ml of isopropyl alcohol, and 300 ml of water were taken and mixed. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was continued at 65 ° C. for 16 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and isopropyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 1 of the present invention.

<Production Example 8>
In a flask equipped with a nitrogen inlet tube, a condenser and a stirrer, 60.0 g of GEMA, 48.0 g of the hydrophobic monomer of Production Example 2, methoxypolyethylene glycol (23) monomethacrylate (trade name “Blemmer PME-1000” Nippon Oil & Fats ( 12.0 g, 300 ml of ethyl alcohol, 30 ml of 0.05 M aqueous sodium carbonate solution and 270 ml of 0.1 M sodium hydrogen carbonate solution were taken and mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution obtained by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was further performed at 60 ° C. for 20 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and ethyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 2 of the present invention.

<Production Example 9>
In a flask equipped with a nitrogen inlet tube, a condenser and a stirrer, 48.0 g of GEA, 36.0 g of the hydrophobic monomer of Production Example 3, methoxypolyethylene glycol (9) methacrylate (manufactured by NOF Corporation, trade name “Blemmer PME” -400 ") 24.0 g, 2-hydroxyethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 12.0 g, isopropyl alcohol 300 ml, 0.2 M aqueous potassium chloride solution 75 ml, 0.2 N hydrochloric acid 15.8 ml and water 209.2 ml Was mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was performed at 70 ° C. for 14 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous potassium hydroxide solution, and isopropyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 3 of the present invention.

<Production Example 10>
In a flask equipped with a nitrogen inlet tube, a condenser and a stirrer, 48.0 g of GEA, 48.0 g of the hydrophobic monomer of Production Example 4, 24.0 g of acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 180 ml of ethylene glycol monomethyl ether Then, 120 m of 0.002N hydrochloric acid was taken and mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 1.0 g of ammonium persulfate in 10 ml of water was added thereto, and the reaction was continued at 65 ° C. for 16 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous potassium hydroxide solution, and ethylene glycol monomethyl ether was removed with a rotary evaporator to obtain an aqueous solution of the copolymer 4 of the present invention.

<Production Example 11>
In a flask equipped with a nitrogen inlet tube, a condenser and a stirrer, 72.0 g of GEMA, 48.0 g of the hydrophobic monomer of Production Example 6, 300 ml of isopropyl alcohol, phosphate buffer solution (pH 6.8) (Nacalai Tesque) 300 ml) was taken and mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was continued at 65 ° C. for 16 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and isopropyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 5 of the present invention.

<Production Example 12>
In a flask equipped with a nitrogen inlet tube, a condenser and a stirrer, 60.0 g of GEA, 48.0 g of the hydrophobic monomer of Production Example 1, polyethylene glycol (9) monomethacrylate (manufactured by NOF Corporation, trade name “Blemmer PE” -400 ") 12.0 g, ethyl acetate 180 ml and ethyl alcohol were taken and mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution obtained by dissolving 0.5 g of benzoyl peroxide in 10 ml of ethyl alcohol was added thereto, and reflux was performed for 8 hours while continuing stirring. After completion of the reaction, 300 g of triglyceryl 2-ethylhexanoate was added, and ethyl acetate and ethyl alcohol were removed with a rotary evaporator to obtain a triglyceryl 2-ethylhexanoate solution of copolymer 6 of the present invention.

<Production Example 13> (Comparative Example)
In a flask equipped with a nitrogen introduction tube, a condenser and a stirrer, 72.0 g of GEMA, 48.0 g of 2-ethylhexyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 300 ml of isopropyl alcohol, phosphate buffer solution (pH 6. 8) 300 ml (manufactured by Nacalai Tesque) was taken and mixed with stirring. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was continued at 65 ° C. for 16 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and isopropyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 7.

<Production Example 14> (Comparative Example)
GEMA 72.0 g, stearyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 48.0 g, isopropyl alcohol 300 ml, and water 300 ml were mixed in a flask equipped with a nitrogen inlet tube, a cooler, and a stirrer. While stirring was continued, nitrogen gas substitution was performed for 1 hour. A solution prepared by dissolving 2.0 g of ammonium persulfate in 20 ml of water was added thereto, and the reaction was continued at 65 ° C. for 16 hours while continuing stirring. After completion of the reaction, the pH was adjusted to 7.0 using an aqueous sodium hydroxide solution, and isopropyl alcohol was removed using a rotary evaporator to obtain an aqueous solution of copolymer 8.

<6> External preparation for skin of the present invention The external preparation of the present invention contains the structural unit I and the structural unit II as essential structural units, and in some cases, structural units derived from hydrophilic monomers, other monomers The copolymer which contains the structural unit derived from as an arbitrary structural unit is contained as an essential component.

  The content of the copolymer in the external preparation for skin of the present invention is preferably 0.5 to 25% by mass, more preferably 1 to 15% by mass. Below the lower limit, the effect of the present invention may not be exhibited, which is not preferable. On the other hand, when the amount is not less than the upper limit value, it is not preferable because the preparation for the external preparation for skin, particularly the solubility in water, is low, and the preparation of the external preparation for skin containing the copolymer uniformly may be difficult.

  As an external preparation for skin of the present invention, external medicines such as ointments, cosmetics and the like can be suitably exemplified. Furthermore, examples of cosmetics include skin care such as cream, milky lotion, skin lotion, and beauty serum, make-up such as under makeup, foundation, eye color, and mascara, and hair cosmetics such as hair tonic, hair liquid, and hair spray. .

The external preparation for skin of the present invention can contain, as an optional component, components that are usually used for external preparations for skin as long as the effects of the invention are not impaired. As such optional components, specifically,
Macadamia nut oil, avocado oil, corn oil, olive oil, rapeseed oil, sesame oil, castor oil, safflower oil, cottonseed oil, jojoba oil, coconut oil, palm oil, liquid lanolin, hydrogenated coconut oil, hydrogenated oil, molasses, hydrogenated castor oil, Oils such as beeswax, candelilla wax, carnauba wax, ibotarou, lanolin, reduced lanolin, hard lanolin, jojoba wax, waxes, liquid paraffin, squalane, pristane, ozokerite, paraffin, ceresin, petrolatum, hydrocarbons such as microcrystalline wax, Higher fatty acids such as oleic acid, isostearic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, undecylenic acid, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, Higher alcohols such as cutyldecanol, myristyl alcohol, cetostearyl alcohol, etc., cetyl isooctanoate, isopropyl myristate, hexyldecyl isostearate, diisopropyl adipate, di-2-ethylhexyl sebacate, cetyl lactate, diisostearyl malate, Di-2-ethylhexanoic acid ethylene glycol, dicaprate neopentyl glycol, di-2-heptylundecanoic acid glycerin, tri-2-ethylhexanoic acid glycerin, tri-2-ethylhexanoic acid trimethylolpropane, triisostearic acid trimethylol Synthetic ester oils such as propane, tetra-2-ethylhexanoic acid pentane erythritol, dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane Linear polysiloxanes such as, cyclic polysiloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexanesiloxane, amino-modified polysiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, etc. Oils such as silicone oils such as modified polysiloxanes, fatty acid soaps (sodium laurate, sodium palmitate, etc.), anionic surfactants such as potassium lauryl sulfate, alkylethanol triethanolamine ether, stearyltrimethylammonium chloride, chloride Cationic surfactants such as benzalkonium and laurylamine oxide, imidazoline-based amphoteric surfactants (2-cocoyl-2-imidazolinium hydroxide-1-cal Boxyethyloxy disodium salt, etc.), betaine surfactants (alkyl betaine, amide betaine, sulfobetaine, etc.), amphoteric surfactants such as acylmethyltaurine, sorbitan fatty acid esters (sorbitan monostearate, sorbitan sesquioleate, etc.) ), Glycerin fatty acids (such as glyceryl monostearate), propylene glycol fatty acid esters (such as propylene glycol monostearate), hydrogenated castor oil derivatives, POE sorbitan fatty acid esters (POE sorbitan monooleate, polyoxyethylene monostearate) Sorbitan, etc.), POE sorbite fatty acid esters (POE-sorbite monolaurate, etc.), POE glycerin fatty acid esters (POE-glycerol monoisostearate, etc.), POE fat Acid esters (polyethylene glycol monooleate, POE distearate, etc.), POE alkyl ethers (POE2-octyldodecyl ether, etc.), POE alkyl phenyl ethers (POE nonylphenyl ether, etc.), Pluronic types, POE / POP alkyl ethers (POE / POP2-decyltetradecyl ether, etc.), Tetronics, POE castor oil / hardened castor oil derivatives (POE castor oil, POE hardened castor oil, etc.), nonionic surfactants such as sucrose fatty acid ester, alkyl glucoside Polyethylene glycol, glycerin, 1,3-butylene glycol, erythritol, sorbitol, xylitol, maltitol, propylene glycol, dipropylene glycol, diglycerin, isoprene Moisturizing composition of polyalcohols such as coal, 1,2-pentanediol, 2,4-hexylene glycol, 1,2-hexanediol, 1,2-octanediol, sodium pyrrolidonecarboxylate, lactic acid, sodium lactate Classification, guar gum, quince seed, carrageenan, galactan, gum arabic, pectin, mannan, starch, xanthan gum, curdlan, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylhydroxypropylcellulose, chondroitin sulfate, dermatan sulfate, glycogen, heparan sulfate, hyaluron Acid, sodium hyaluronate, tragacanth gum, keratan sulfate, chondroitin, mucoitin sulfate, hydroxyethyl guar gum, carboxymethyl guar gum, dextran , Keratosulfuric acid, locust bean gum, succinoglucan, caronic acid, chitin, chitosan, carboxymethyl chitin, agar, polyvinyl alcohol, polyvinyl pyrrolidone, carboxyvinyl polymer, sodium polyacrylate, polyethylene glycol, bentonite and other thickeners, Lower alcohols such as ethanol and isopropanol, hexyl diethylaminohydroxybenzoylbenzoate, t-butylmethoxybenzoylmethane, paraaminobenzoic acid UV absorber, anthranilic acid UV absorber, salicylic acid UV absorber, cinnamic acid UV absorber UV absorbers, vitamin A or its derivatives, vitamin B6 hydrochloride, vitamin B6 tripalmitate, vitamin B6 dioctanoate, vitamin B2 or its derivatives, vitamin B12, vitamin B15 such as vitamin B15 or derivatives thereof, α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E such as vitamin E acetate, vitamin D, vitamin H, pantothenic acid, panthetin, pyrroloquinoline quinone, etc. Of these, vitamins can be preferably exemplified.

The external preparation for skin of the present invention can be prepared by treating the above essential components and optional components by a conventional method.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, it cannot be overemphasized that this invention is not limited only to these Examples.

<Examples 1-3, Comparative Examples 1-3>
The ingredients listed in Table 2 were stirred and mixed, and stirring was continued at room temperature until a uniform transparent solution was obtained, thereby obtaining the lotion of the present invention and the lotion of the comparative example. In addition, the number in a table | surface means the mass%.

<Test Example 1> Evaluation of Skin Barrier Function Improvement Action Transepidermal water loss (TEWL) (measured using TEWAMETER TM210: curation + khazaka) is a panel having a skin barrier function of 30 (g / m ² hr) or more. It selected as the panel which has fallen, and evaluated the skin barrier function improvement effect at the time of apply | coating the skin lotion of Examples 1-3 and Comparative Examples 1-3 to skin.

Lotion was applied to the application site of the arm twice in the morning and evening for 7 consecutive days. Apply a 0.01% by weight lactic acid aqueous solution to the skin lotion application site before the start of the skin lotion application test and when applied for 7 days, evaluate the irritation felt as the following three levels of stimulation protection scores, and compare the two Thus, the skin barrier function improving effect was evaluated. The stimulation defense score was the average of the stimulation defense scores of 10 panelists. The results are shown in Table 3. In addition, it means that irritation | stimulation is hard to feel, that is, a skin barrier function is so high that a stimulation defense score is high.
Stimulation defense score: 1 point I feel a lot of stimulation.
2 points I feel some stimulation.
3 points I feel slight irritation.
4 points I hardly feel any irritation.
5 points I do not feel any stimulation.

<Test Example 2> Measurement of dynamic friction coefficient 1 cm from the longitudinal end of a strip (15 cm × 5 cm) of a synthetic leather made of polyurethane similar to human skin (previously cleaned with ethanol before the test), 3 cm × 3 cm × In the range of 3 cm, the skin lotions of Examples 1 to 3 and the skin lotions of Comparative Examples 1 to 3 are uniformly applied and fixed to the experimental table with double-sided tape. On the other hand, the same synthetic leather piece 3 cm × 3 cm is attached to a jig for placing a load with double-sided tape. The jig was placed on the coated surface of the sample so that the surface of the synthetic leather faced, a load of 200 g was placed, and the frictional resistance was measured with a surface property tester (Trilab Handy Love Tester Type TL701). The measurement conditions were a sweep speed of 200 mm / sec, a sweep distance of 10 cm, a repeat count of 10 times, and the average of the 10 frictional resistance values in the forward path was defined as the dynamic frictional resistance value. The dynamic friction coefficient was calculated by dynamic friction resistance value / load. A smaller dynamic friction coefficient indicates that there is no resistance to slipping. The results are shown in Table 3.

<Test Example 3> Evaluation of flexibility of coating film The skin lotions of Examples 1 to 3 and Comparative Examples 1 to 3 were applied on a styrene film having a thickness of 0.1 mm and dried at 80 ° C. for 4 hours. A test piece was prepared. This test piece was bent back and forth, and the number of bendings at which cracks occurred on the surface of the coating film was measured to determine the flexibility of the coating film. The greater the number of times, the more flexible the coating. The results are shown in Table 3.

<Test Example 4>
By five skilled evaluators, the squeak during use of the lotions of Examples 1 to 3 and the lotions of Comparative Examples 1 to 3 and sensory feeling after use were subjected to sensory evaluation according to the following evaluation criteria.
Feeling tight 1: Feeling quite tight 2: Feeling tight 3: Feeling a little bit 4: Feeling a little bit felt 5: Feeling nothing at all
Squeak 1: Feels squeak fairly 2: Feels squeak 3: Feels squeak slightly 4: Feels squeak slightly 5: Does not feel squeak at all
In addition, evaluation was performed by setting the skin lotion of Comparative Example 1 to 3.0, and the average value of the scores of 5 people was used as the sample score. The results are shown in Table 3.

表３の結果から明らかなように、本発明の皮膚外用剤は、皮膚バリアー機能の向上作用に優れ、かつ、肌上で柔軟で、動摩擦係数の低い塗布膜を与えるので、使用中のきしみ、使用後のつっぱり感のない良好な使用感を与える。

As is apparent from the results in Table 3, the external preparation for skin of the present invention is excellent in the action of improving the skin barrier function, is soft on the skin, and gives a coating film having a low coefficient of dynamic friction. Gives a good feeling of use after use.

<Examples 4-6, Comparative Examples 4-6>
Based on the formulation in Table 4, an emulsion that is an external preparation for skin of the present invention and an emulsion of a comparative example were prepared. That is, the component (I) in Table 4 was heated and mixed with dissolution at 75 ° C., and a solution in which the component (B) was heated and mixed at 75 ° C. was gradually added and emulsified while stirring. Then, it cooled and when it became 40 degreeC, the solution which mixed and dissolved the component (c) was added, it cooled to room temperature, and the emulsion was obtained. In addition, the number in a table | surface means the mass%. Regarding the obtained emulsions of Examples 4 to 6 and the emulsions of Comparative Examples 4 to 6, in the same manner as in Test Examples 1 to 4, the effect of improving the skin barrier function, the coefficient of friction of the coating film, the flexibility, and in use The squeakiness and the feeling of tension after use (comparative example 4 was 3 points) were evaluated. The results are shown in Table 5.

表５の結果より、本発明の皮膚外用剤は、皮膚バリアー機能の向上作用に優れ、かつ、肌上で柔軟で、動摩擦係数の低い塗布膜を与えるので、使用中のきしみ、使用後のつっぱり感のない良好な使用感を与えることが乳化系においても実証された。

From the results of Table 5, the external preparation for skin of the present invention is excellent in the action of improving the skin barrier function, is soft on the skin and gives a coating film having a low coefficient of dynamic friction. It was also demonstrated in an emulsifying system that it gives a good feeling without feeling.

<Examples 7-9 Comparative Examples 7-9>
According to the formulation of Table 6, a foundation, which is an external preparation for skin of the present invention, was prepared. That is, after component (a) was heated to 75 ° C., mixed and dissolved, component (b) was dispersed therein using a disper. While stirring, a solution in which the component (c) was heated and dissolved at 75 ° C. was gradually added to emulsify, and then stirring was continued to cool to room temperature to obtain a foundation. In addition, the number in a table | surface means the mass%. Regarding the foundations of Examples 7 to 9 and the foundations of Comparative Examples 7 to 9 that were obtained, the same method as in Test Examples 1 to 4, was used to improve the skin barrier function, the coefficient of friction of the coating film, the flexibility, and in use The creaking and the feeling of tension after use (comparative example 7 was set to 3 points) were evaluated. The results are shown in Table 7.

表７の結果より、本発明の皮膚外用剤が、皮膚バリアー機能の向上作用に優れ、かつ、肌上で柔軟で、動摩擦係数の低い塗布膜を与えるので、使用中のきしみ、使用後のつっぱり感のない良好な使用感を与えることがメークアップ化粧料においても実証された。

From the results of Table 7, since the external preparation for skin of the present invention is excellent in the action of improving the skin barrier function, gives a coating film that is soft on the skin and has a low coefficient of dynamic friction, squeak during use, and tension after use. It has also been demonstrated in makeup cosmetics that it gives a good feeling without feeling.

The present invention is used for cosmetics and the like.

Claims (6)

One or more structural units derived from a monomer represented by the following general formula (I), and one or more structural units derived from a hydrophobic monomer represented by the general formula (II) An external preparation for skin, comprising a copolymer having as an essential structural unit.
Formula (I)

(I)

(In general formula (I), R ¹ represents a hydrogen atom or a methyl group, G—O— represents a group in which hydrogen is removed from the hydroxyl group at the 1-position of the reducing sugar, n is 2 or 3, and m is 1 to 5). Represents an integer.)
Formula (II)

(II)

(In General Formula (II), R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ³ represents a branched hydrocarbon group having 13 to ³⁰ carbon atoms or a ring structure that does not include a ring structure. (A hydrocarbon group having 6 to 12 carbon atoms having two or more branches not included) Furthermore, the copolymer contains a structural unit derived from one or more monomers selected from the group consisting of a polymerizable carboxylic acid and a salt thereof, and a hydrophilic monomer represented by the following general formula (III). The external preparation for skin according to claim 1, wherein
Formula (III)

(III)

(In general formula (III), R ⁴ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁵ represents an alkylene group having 2 to 4 carbon atoms which may have a hydroxyl group, and R ⁶ represents hydrogen. An atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an acyl group having 1 to 12 carbon atoms, p represents an integer of 4 to 40.) The external preparation for skin according to claim 2, wherein the hydrophilic monomer represented by the general formula (III) is a hydrophilic monomer represented by the following general formula (IV).
Formula (IV)

(IV)

(In general formula (IV), R ⁷ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ⁸ represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or an aliphatic group having 1 to 14 carbon atoms. And represents a hydrocarbon group or an acyl group having 1 to 12 carbon atoms, q represents an integer of 4 to 40.) The external preparation for skin according to claim 2 or 3, wherein the polymerizable carboxylic acid is acrylic acid and / or methacrylic acid. The skin external preparation according to any one of claims 1 to 4, wherein the copolymer is contained in an amount of 0.5 to 25% by mass based on the total amount of the external preparation for skin. It is cosmetics, The skin external preparation in any one of Claims 1-5 characterized by the above-mentioned.