WO2016204258A1

WO2016204258A1 - Polymer for gel formation and dermatological adhesive material

Info

Publication number: WO2016204258A1
Application number: PCT/JP2016/068029
Authority: WO
Inventors: 翼菓子野; 武久岩間; 柴田　雅史
Original assignee: 日産化学工業株式会社
Priority date: 2015-06-19
Filing date: 2016-06-17
Publication date: 2016-12-22
Also published as: JPWO2016204258A1

Abstract

A dermatological adhesive material that is a liquid composition including (a) a copolymer that includes monomer units (I) having a polyalkylene glycol skeleton with a degree of polymerization of 2-100 in a side chain and monomer units (II) having a C3-30 branched alkyl group in a side chain, (b) water, and (c) an oily component, and changes into a gel on the skin. A hydrogel having excellent tight adhesiveness to the skin surface on the skin and adhesiveness to the skin can be formed by applying this dermatological adhesive material to skin.

Description

Gel forming polymer and adhesive material for skin

The present invention relates to a gel-forming polymer, a gel-forming polymer mixture, a skin-adhesive material, and a skin-adhesive gel suitable as a base for external preparations for skin, such as cosmetics and external preparations for skin use used in the skin care field.

Conventionally, for the purpose of healing skin conditions such as skin conditioning and beautiful skin and acne, creams, lotions, emulsions, and pack agents containing film forming agents such as polyvinyl alcohol and polyacrylate Various forms of the topical skin preparation are commercially available.

These external preparations for skin are effective by infiltrating the skin with active ingredients and water contained therein, and the effects are maintained by keeping the skin infiltrated and hydrating the skin. It can be used to the fullest. Since the permeability of active ingredients and moisture is determined by the partition coefficient between the base and the skin, it is very important that the skin and the base come into close contact with each other. However, creams, lotions, and emulsions have fluidity, so they sag and flow when used, and dry relatively quickly even when applied to the application site, so that the skin is sufficiently hydrated. Is difficult to keep. Therefore, the development of a base for keeping moisture and active ingredients at the application site for a long time has been actively researched and developed.

As such a base, for example, there is a sheet-like base in which a layer of a composition containing a polymer or copolymer and a crosslinking agent is formed on a support, and more specifically, the polymer or copolymer Water-soluble sheet-like base using polyvinyl alcohol, polyacrylic acid or a salt thereof as a combination, a hydrophobic copolymer using a rubber-based copolymer or a silicone-based copolymer as a polymer or copolymer There is a sheet-like base. Generally, a skin external preparation using a water-soluble sheet base is called a poultice, and a skin external preparation using a hydrophobic sheet base is called a tape. These external preparations for skin, such as cataplasms and tapes, are applied directly to the application site of the skin, so that moisture and active ingredients can permeate continuously, so that the moisture and active ingredients remain in the application site for a long time. Have

However, the external preparation for skin using the above sheet-like base also has disadvantages. That is, there are very fine irregularities on the skin surface, and it is difficult to say that the solidified sheet-like base is completely in contact with the skin surface, and there are always voids. Therefore, the adhesiveness of the base to the skin is weak, and the external preparation for skin may fall off during daily activities. In addition, moisture and the like in the base evaporate with time and cure to lose flexibility. If the patch or tape loses its flexibility, it will not be able to follow the movement of the body of the applicator, and the adhesion to the skin will be further reduced, making it easier to peel off, and active ingredients and moisture will not penetrate into the skin well. A phenomenon occurs. For this reason, Patent Documents 1 to 3 propose a base formulation that improves the adhesiveness and prevents moisture evaporation by devising the composition of the adhesive (polymer or copolymer). The problem of making the agent correspond to fine irregularities on the skin surface, that is, sufficient adhesion of the base to the skin surface having fine irregularities, has not been solved.

In order to make the base correspond to fine irregularities on the skin surface, for example, as shown in Patent Documents 4 and 5 and the like, a method of softening the sheet-like base in a gel form is conceivable. However, in that case, the solidity of the base cannot be maintained, which may cause dripping or the like during use, or the base remains when peeled off, resulting in poor use feeling due to stickiness, skin blurring, and the like. However, since the issue of safety to the living body is usually given priority over the adhesion to the skin, the formulation of the base will place emphasis on the formulation for suppressing skin irritation, etc. The problem of sufficient adhesion of the base to the surface has not been fully solved.

Furthermore, the biggest problem with external preparations for skin using a sheet-like base is a phenomenon in which it is difficult for drugs and moisture to transfer from the base to the skin. That is, for example, the tape agent is a polymer or copolymer that becomes an adhesive, a cross-linking agent that cross-links the polymer or copolymer, and an active ingredient and moisture. It is obtained by spreading the mixture on the support, but at that time, the active ingredient and moisture are partially bonded to the crosslinking agent or polymer due to the chemical reaction with the crosslinking agent or polymer, so the tape agent is applied Even if affixed to the site, the active ingredient and water do not transfer to the skin, and the effect may not be sufficiently exhibited. In order to solve this problem, for example, Patent Document 6 has developed a copolymer having a structure capable of directly crosslinking between copolymers without using a crosslinking agent composed of a low-molecular compound, and effective in that. A combination of ingredients and moisture has been proposed to improve the transfer of active ingredients and moisture to the skin compared to existing sheet bases. No mention is made of the problem of adhesion and the problem of adhesiveness of the base material over time.

On the other hand, there is a so-called film forming agent in which a solution in which a polymer or a copolymer is dissolved is directly applied to an application site, and the solution is dried on the skin to form a film. As a film forming agent, a film forming agent using a highly unique artificial synthetic copolymer in order to exhibit a specific function in addition to those actually used for a long time using polyvinyl pyrrolidone, polyvinyl alcohol, etc. (For example, Patent Document 7: Nail polish applied to nails and the like, Patent Document 8: Antibacterial and antifouling, Patent Document 9: Protection from external stimuli such as ultraviolet rays, Patent Document 10: Hairdressing, Patent Document 11) : Prevention of skin roughness due to drying, Patent Documents 12 and 13: General makeup such as eyeliner, mascara, facial cosmetics, etc.).

However, all of these film-forming agents are those whose moisture is dried and the polymer itself formed into a film on the skin exhibits its function in the intended use. It is not intended for continuous penetration into the skin.

JP 2011-88890 A Japanese Patent Laid-Open No. 6-40893 JP 2013-216636 A JP-A-6-142178 JP-A-8-208459 JP 2009-149660 A JP-A-2005-350466 JP 2010-5161 A Japanese Patent Laid-Open No. 5-331019 Special table 2006-508937 JP 2003-12437 A JP 2006-507367 A Special table 2014-528420 gazette

The present invention has been made in view of the above circumstances, and the problem to be solved is a novel adhesive for skin that can form a hydrogel excellent in adhesion to the skin surface and adhesion to the skin. It is to provide a material and to provide a gel-forming polymer material for use in the adhesive material for skin.

The inventors have completed the present invention as a result of intensive studies from a completely new viewpoint in order to solve the above problems. That is, a liquid material (sol) containing moisture and polymer is applied to the skin to wet the skin crevice, and a part of the moisture in the liquid volatilizes or is absorbed into the skin to quickly gel. In the hypothesis that the resulting gel will adhere to the skin surface without forming a gap, and the adhesiveness will not easily decrease over time. As a result of research, a copolymer having a monomer unit containing a polyalkylene glycol skeleton having a specific degree of polymerization in the side chain and a monomer unit containing a branched alkyl group having a specific number of carbon atoms in the side chain is converted into an aqueous solvent. It has been found that the dispersion liquid dispersed in can be a material that quickly gels on the skin when applied to the above skin, and has completed the present invention.

That is, the present invention is as follows.
[1] A monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and a monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain A gel-forming polymer comprising the copolymer (A).
[2] The monomer unit (I) is a monomer unit represented by the following formula (1), and the monomer unit (II) is a monomer unit represented by the following formula (2) The polymer according to the above [1], wherein

(Wherein R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents —O—, —CH ₂ —O—, —CO—, —CO—O—, or —CO—NR ² —). Here, R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, A represents an alkylene group, 2 ≦ n ≦ 100 .)

(Wherein R ⁴ represents a hydrogen atom or a methyl group, X ² represents —O—, —CH ₂ —O—, —CO—, or —CO—O—, and R ⁵ represents 3 carbon atoms) Represents 30 to 30 branched alkyl groups.)

[3] The polymer according to the above [2], wherein the oxyalkylene group represented by A—O in the formula (1) is an ethylene oxide group.
[4] The above [2], wherein the branched alkyl group having 3 to 30 carbon atoms represented by R ⁵ in the formula (2) is any one of groups represented by the following formulas (4) to (6): ] Or the polymer according to [3].

[5] The copolymerization ratio a1 ((1) :( 2)) of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (2) in the copolymer (A) is: 5. The polymer according to any one of the above [2] to [4], which is 5:95 to 90:10 (molar ratio).
[6] Any one of the above [1] to [4], wherein the copolymer (A) further comprises a monomer unit (III) having a linear alkyl group having 3 to 30 carbon atoms in the side chain. The polymer described in 1.
[7] The polymer according to [6], wherein the monomer unit (III) is a monomer unit represented by the following formula (3).

(Wherein R ⁶ represents a hydrogen atom or a methyl group, X ³ represents —O—, —CH ₂ —O—, —CO—, or —CO—O—, and R ⁷ represents 3 carbon atoms) Represents a linear alkyl group of ˜30.)
[8] Co-polymerization of the monomer unit represented by the formula (1), the monomer unit represented by the formula (2), and the monomer unit represented by the formula (3) in the copolymer (A). The polymerization ratio a2 ((1) :( 2) :( 3)) is 5 to 60:10 to 90: 5 to 50 (molar ratio) (however, the numerical values of (1), (2) and (3) The polymer according to [7] above, wherein the total is 100).
[9] including a monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and a monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain Copolymer (A);
Copolymer containing a monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and a monomer unit (III) having a linear alkyl group having 3 to 30 carbon atoms in the side chain A gel-forming polymer mixture comprising the coalescence (B).
[10] The monomer unit (I) is a monomer unit represented by the following formula (1), and the monomer unit (II) is a monomer unit represented by the following formula (2). The polymer mixture according to the above [9], wherein the monomer unit (III) is a monomer unit represented by the following formula (3).

(Wherein R ⁶ represents a hydrogen atom or a methyl group, X ³ represents —O—, —CH ₂ —O—, —CO—, or —CO—O—, and R ⁷ represents 3 carbon atoms) Represents a linear alkyl group of ˜30.)
[11] The polymer mixture according to the above [10], wherein the oxyalkylene group represented by A—O in the formula (1) is an ethylene oxide group.
[12] The branched alkyl group having 3 to 30 carbon atoms represented by R ⁵ in the formula (2) is any one of groups represented by the following formulas (4) to (6). Or a polymer mixture according to [11].

[13] The copolymerization ratio a3 ((1) :( 2)) of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (2) in the copolymer (A) is: 1:99 to 90:10 (molar ratio), and the copolymer ratio of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (3) in the copolymer (B) The polymer mixture according to any one of [10] to [12] above, wherein b1 ((1) :( 3)) is 1:99 to 90:10 (molar ratio).
[14] (a) The polymer or polymer mixture according to any one of [1] to [13] above,
A liquid composition comprising (b) water, and (c) an oil component,
An adhesive material for skin that turns into a gel on the skin.
[15] The adhesive material for skin according to [14], further comprising (d) an organic solvent.
[16] The material according to [14] or [15] above, which is used as a base for an external preparation for skin.
[17] The material according to [16] above, wherein the external preparation for skin is a cosmetic.
[18] The material according to [16] above, wherein the external preparation for skin is an external preparation for skin.
[19] A method for forming a skin adhesive gel, comprising bringing the skin adhesive material according to [14] or [15] into contact with the skin.

According to the present invention, it is possible to provide a novel gel-forming polymer or polymer mixture that is gelled by coexisting with water and that exhibits adhesiveness to the skin.

In addition, by including such a gel-forming polymer or polymer mixture, it is a liquid before application to the skin, but has excellent adhesion to the skin surface on the skin and good adhesion to the skin. It is possible to realize a pressure-sensitive adhesive material for skin that preferably changes to a gel (preferably a hydrogel having excellent adhesion to the skin surface, good adhesion to the skin, and no stickiness).

The adhesive material for skin obtained by the present invention is suitable as a base for external preparations for skin, and when used as a base for external preparations for skin, the base adheres to the skin and the skin is sufficiently hydrated. Since the moist state can be maintained, it is possible to obtain a skin external preparation excellent in the penetration of active ingredients and moisture into the skin.

2 is a phase diagram of the composition prepared in Example 3. FIG. 2 is a phase diagram of the composition prepared in Example 4. FIG. 2 is a phase diagram of the composition prepared in Example 5. FIG. 2 is a phase diagram of the composition prepared in Example 6. FIG. 2 is a phase diagram of the composition prepared in Comparative Example 1. FIG.

Hereinafter, the present invention will be described in detail.
[Polymer for gel formation]
The gel-forming polymer of the present invention comprises a monomer unit (I) having a polyalkylene glycol skeleton having a degree of polymerization of 2 to 100 in the side chain and a monomer having a branched alkyl group having 3 to 30 carbon atoms in the side chain. It consists of a copolymer (A) containing unit (II).

Copolymer (A) gels by coexisting with water. That is, the polyalkylene glycol skeletons having a degree of polymerization of 2 to 100 in the side chain of the monomer unit (I) are cross-linked via water molecules to form a gel and form a hydrogel. On the other hand, the branched alkyl group having 3 to 30 carbon atoms in the side chain of the monomer unit (II) gives skin adhesiveness. Accordingly, a skin-adhesive hydrogel can be formed.

The monomer unit (I) is preferably a monomer unit represented by the following formula (1) (hereinafter also abbreviated as “monomer unit of formula (1)”).

In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and X ¹ represents —O—, —CH ₂ —O—, —CO—, —CO—O— or —CO—NR ² —. . Note that R ² in —CO—NR ² — represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

R ³ represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group, and more preferably a hydrogen atom or a methyl group.

A represents an alkylene group, and the alkylene group preferably has 1 to 5 carbon atoms, more preferably 2 to 3 carbon atoms.

— (A—O) _n — represents a polyalkylene glycol skeleton, and the oxyalkylene group represented by A—O may be composed of one oxyalkylene group, for example, an ethylene oxide group and You may be comprised from multiple types of oxyalkylene groups, such as two types with a propylene oxide group.

The polymerization degree n of the polyalkylene glycol skeleton is 2 ≦ n ≦ 100, preferably 5 ≦ n ≦ 10000, more preferably 10 ≦ n ≦ 100, and particularly preferably 10 ≦ n ≦ 50. . If n is in such a preferable range, a sufficient effect can be easily obtained.

The monomer unit of the formula (1) is a unit derived from a (meth) acrylic monomer (wherein X ¹ is —CO—O—), a unit derived from a (meth) allyl ether monomer (formula Wherein X ¹ is —CH ₂ —O—), a unit derived from a vinyl ether monomer (wherein X ¹ is —O—), and a unit derived from a (meth) acrylamide monomer (wherein X ¹ is preferably any one or more selected from —CO—NR ² —), more preferably a unit derived from a (meth) acrylic monomer. In the present specification, “(meth) acryl” means both “acryl” and “methacryl”.

In the most preferred embodiment of the monomer unit of the formula (1), R ¹ is a methyl group, X ¹ is —CO—O—, and — (A—O) _n — has a degree of polymerization of 10 to 100 polyethylene glycol residues, polyethylene glycol methacrylate, wherein R ³ is a hydrogen atom.

The monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain is preferably a monomer unit represented by the following formula (2) (hereinafter referred to as “single unit of the formula (2) It is also abbreviated as “mer unit”).

In formula (2), R ⁴ represents a hydrogen atom or a methyl group, and X ² represents —O—, —CH ₂ —O—, —CO—, or —CO—O—. R ⁵ represents a branched alkyl group having 3 to 30 carbon atoms.

Examples of the branched alkyl group having 3 to 30 carbon atoms represented by R ⁵ include isopropyl group, isobutyl group, sec-butyl group, t-butyl group, isohexyl group, isoheptyl group, isopentyl group, neopentyl group, t- Pentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group 1,1-dimethylbutyl group, 2,2-dimethylbutyl group, 3,3-dimethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 1 -Ethylbutyl group, 2-ethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group, 1-ethyl-1-methyl Propyl group, 1-ethyl-2-methylpropyl group, isooctyl group, isononyl group, isodecyl group, isolauryl group, isopalmityl group, isomyristyl group, isostearyl group, isoeicosyl group, represented by the following formulas (4) to (9) And the group represented. Of these, those having 4 to 24 carbon atoms are preferred, those having 6 to 20 carbon atoms are more preferred, and groups represented by the following formulas (4) to (9) are particularly preferred. Most preferably, they are groups represented by the following formulas (4) to (6).

The monomer unit of the formula (2) is a unit derived from a (meth) acrylic monomer (wherein X ² is —CO—O—), a unit derived from a (meth) allyl ether monomer (formula Wherein X ² is —CH ₂ —O—) and a unit derived from a vinyl ether monomer (wherein X ² is —O—), and is preferably one or more of them, More preferably, it is a unit derived from a (meth) acrylic monomer.

In the most preferred embodiment of the monomer unit of the formula (2), R ⁴ is a hydrogen atom or a methyl group, X ² is —CO—O—, and R ⁵ is a branched alkyl of the formula (4) It is a (meth) acrylate monomer that is a group.

The copolymer (A) may be either a random copolymer or a block copolymer, but is preferably a random copolymer. The copolymerization ratio a1 ((1) :( 2)) of the monomer unit of the formula (1) and the monomer unit of the formula (2) is 5:95 to 90 in terms of molar ratio. : 10 is preferable, 15:85 to 80:20 is more preferable, 20:80 to 70:30 is still more preferable, and 20:80 to 55:45 is particularly preferable. When the ratio of the monomer unit of formula (1) is too small, it is difficult to form a gel on the skin, and when it is too large, adhesion to the skin is difficult to obtain.

From the viewpoint of suppressing the stickiness of the hydrogel formed by the copolymer (A), the copolymer (A) is a monomer unit having a linear alkyl group having 3 to 30 carbon atoms in the side chain ( It may be a copolymer further comprising III).

The monomer unit (III) is preferably a monomer unit represented by the following formula (3) (hereinafter also abbreviated as “monomer unit of formula (3)”).

(Wherein R ⁶ represents a hydrogen atom or a methyl group, X ³ represents —O—, —CH ₂ —O—, —CO—, or —CO—O—, and R ⁷ represents 3 carbon atoms) Represents a linear alkyl group of ˜30.)

In the formula (3), the linear alkyl group having 3 to 30 carbon atoms represented by R ⁷ is, for example, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group. Group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group N-octadecyl, n-nonadecyl, n-icosyl group, n-henicosyl group, n-docosyl group, n-tricosyl group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n -Octacosyl group, n-nonacosyl group, n-triacontyl group and the like. Of these, those having 4 to 24 carbon atoms are preferable, those having 6 to 20 carbon atoms are more preferable, and n-hexadecyl group and n-octadecyl group are particularly preferable.

The monomer unit of the formula (3) is a unit derived from a (meth) acrylic monomer (wherein X ³ is —CO—O—), a unit derived from a (meth) allyl ether monomer (formula Wherein X ³ is —CH ₂ —O—) and a unit derived from a vinyl ether monomer (wherein X ³ is —O—), and is preferably one or more of them, More preferably, it is a unit derived from a (meth) acrylic monomer.

The most preferred embodiment of the monomer unit of the formula (3) is a methacrylate type unit wherein R ⁶ is a methyl group, X ³ is —CO—O—, and R ⁷ is an n-octadecyl group. It is a mer.

When the copolymer (A) is a copolymer containing the monomer unit of the formula (3), the copolymer (A) may be either a random copolymer or a block copolymer. A random copolymer is preferred. Further, a copolymerization ratio a2 ((1) :( 2) :( 3)) of the monomer unit of the formula (1), the monomer unit of the formula (2), and the monomer unit of the formula (3) Is preferably 5 to 60:10 to 90: 5 to 50 (provided that the sum of the three numerical values is 100) in terms of molar ratio. If the proportion of the monomer unit of the formula (1) is too small, it is difficult to form a gel on the skin, and if the proportion of the monomer unit of the formula (3) is too small, the sticking suppression effect of the gel is sufficient. When it becomes difficult to obtain and is too large, the skin adhesiveness of the gel tends to decrease.

The weight average molecular weight (Mw) of the copolymer (A) is preferably 5000 to 200,000, more preferably 10,000 to 100,000. When the weight average molecular weight (Mw) is less than 5000, adhesion to the skin and gelling ability tend to be difficult to be expressed. When the weight average molecular weight (Mw) is greater than 200000, for example, when an organic solvent (diluent) described later is used, It tends to be difficult to mix with organic solvents. If the weight average molecular weight (Mw) is within such a preferable range, a sufficient effect is easily obtained.

The weight average molecular weight (Mw) in the present invention is measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the weight average molecular weight by the GPC method is manufactured by Tosoh Corporation, HLC-8320GPC Eco-SEC as a measuring device, Tosoh Corporation, SuperHZ as a column, tetrahydrofuran or the like as a mobile phase, It can be measured at a column temperature of 25 ° C. and calculated using a standard polystyrene calibration curve.

In the above, the gel-forming polymer of the present invention has a monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and a branched alkyl group having 3 to 30 carbon atoms in the side chain. The copolymer (A) containing the monomer unit (II) is added to the monomer units of the formulas (1) and (2), and the monomer unit of the formula (3) is further copolymerized. Although it has been explained that the effect of suppressing the stickiness of the hydrogel formed by the copolymer (A) is enhanced by using the polymer, the gel-forming polymer of the present invention has a polymerization degree of 2 to 100 in the side chain. A copolymer (A) containing a monomer unit (I) having a polyalkylene glycol skeleton and a monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain, and polymerized in the side chain Has a polyalkylene glycol skeleton of 2 to 100 degrees In the form of a mixture (polymer mixture) with a monomer unit (I) and a copolymer (B) containing a monomer unit (III) having a linear alkyl group having 3 to 30 carbon atoms in the side chain There may be.

In the case of such a polymer mixture of the copolymer (A) and the copolymer (B), the preferred embodiment of the copolymer (A) is the monomer unit of the above formula (1) and the above formula (3). It is a copolymer with monomer units. The monomer unit (I) in the copolymer (B) is preferably a monomer unit of the above formula (1), and the monomer unit (III) is preferably the above-mentioned monomer unit (III). It is a monomer unit of formula (3). In addition, the preferable aspect of the monomer unit of Formula (1) and the monomer unit of Formula (3) in this case follows that in the above-mentioned copolymer (A).

The copolymer (A) in the polymer mixture may be either a random copolymer or a block copolymer, but a random copolymer is preferred. The copolymerization ratio a3 ((1) :( 2)) of the monomer unit of the formula (1) and the monomer unit of the formula (2) is 1:99 to 90 in terms of molar ratio. : 10 is preferable, and 5:95 to 80:20 is more preferable. If the proportion of the monomer unit of the formula (1) is too small, there is a possibility that a powdery precipitation of the copolymer occurs on the skin, and if it is too large, it tends to be difficult to suppress the stickiness of the gel. .

The copolymer (B) in the polymer mixture may be either a random copolymer or a block copolymer, but a random copolymer is preferred. The copolymerization ratio b1 ((1) :( 3)) of the monomer unit of the formula (1) and the monomer unit of the formula (3) is 1:99 to 90 in terms of molar ratio. : 10 is preferable, 5:95 to 80:20 is more preferable, 10:90 to 80:20 is still more preferable, and 10:90 to 55:45 is particularly preferable. If the proportion of the monomer unit of formula (1) is too small, it tends to be difficult to form a gel on the skin, and if it is too large, the copolymer may be precipitated in the form of powder on the skin. Further, the weight average molecular weight (Mw) of the copolymer (B) is preferably from 5,000 to 200,000, more preferably from 10,000 to 100,000. If the weight average molecular weight (Mw) is less than 5000, the sticking suppression effect is hardly exhibited, and if it is more than 200000, the stickiness may be increased. If the weight average molecular weight (Mw) is within such a preferable range, a sufficient effect is easily obtained. If it is out of the above range, it becomes difficult to obtain adhesion to the skin.

The mixing ratio ((A) :( B)) of the copolymer (A) and the copolymer (B) in the polymer mixture is determined depending on the copolymerization ratio a3 in the copolymer (A) and the copolymer (B). Generally, the mass ratio is preferably 95: 5 to 10:90, more preferably 90:10 to 40:60, although it varies depending on the polymerization ratio b1. If the ratio of the copolymer (B) is too small, the sticking suppression effect tends to be hardly exhibited, and if too large, the adhesion to the skin tends not to be sufficiently exhibited.

Copolymer (A) and copolymer (B) are, for example, monomer units of formulas (1) and (2), monomer units of formulas (1) to (3), or formula (1) ) And (3) can be obtained by polymerizing a monomer mixture to be used in the monomer unit in an inert gas atmosphere such as nitrogen in the presence of a radical polymerization initiator. The polymerization (reaction temperature) may be performed by heating or cooling to a temperature suitable for the polymerization initiator. Examples of the polymerization method include solution polymerization, dispersion polymerization, precipitation polymerization, bulk polymerization, and the like. Among these, solution polymerization or precipitation polymerization is preferable. In particular, it is preferable to carry out the reaction by solution polymerization in an organic solvent from the viewpoint of molecular weight control. Examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, and isopropanol; esters such as methyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as benzene and toluene; From the viewpoint of the safety of the polymer to the living body, alcohols are preferred. The solvent can be used alone or in combination of two or more. In the case of solution polymerization in an organic solvent, the content of the organic solvent in the entire polymerization reaction product is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight per 1 part by weight of the total amount of all monomers. It is.

The polymerization initiator may be a general one used for copolymerization of a monomer having a radical polymerizable double bond, and an azo polymerization initiator is preferably used. Examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile. 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, dimethyl 2,2′-azobisisobutyrate and the like. These can use 1 type (s) or 2 or more types. Among them, dimethyl 2,2'-azobisisobutyrate is particularly preferable from the viewpoint of safety of the obtained polymer to the living body. The amount of the polymerization initiator is preferably 1 to 100 mol%, more preferably 3 to 50 mol%, based on the total amount of monomers.

The polymerization reaction product containing the copolymer (copolymer (A) or copolymer (B)) produced by the polymerization reaction is appropriately dried, filtered, etc., and the copolymer is collected. For example, when a copolymer is synthesized by solution polymerization, the solvent is concentrated (volatilized) by drying under reduced pressure, and the copolymer is collected.

[Skin adhesive material]
(A) The gel-forming polymer or polymer mixture of the present invention, that is, the copolymer (copolymer (A) or copolymer (A) and copolymer (B) obtained as described above) For example, (b) water, (c) oily components, etc. are added to prepare a liquid composition of an emulsion (O / W emulsion). Such a liquid composition becomes the adhesive material for skin of the present invention. The copolymer (copolymer (A) or a mixture of the copolymer (A) and the copolymer (B)) obtained as described above has a high viscosity and is an emulsion (O / W When it is difficult to form an emulsion, it is preferable to prepare a liquid composition by further adding (d) an organic solvent as a copolymer diluent.

(B) The water is preferably ultrapure water, pure water, purified water or tap water, more preferably pure water or purified water. However, it is not limited to these, and for example, perfume containing a fragrance, or fruit juice water that is naturally derived water can be used, and there is no particular limitation.

(C) The oily component is not particularly limited, and includes hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, liquid oils, silicone oils and the like that are usually used in cosmetics, skin external medicines, and the like. 1 type (s) or 2 or more types can be used.

Examples of the hydrocarbon oil include isododecane, isohexadecane, isoparaffin, paraffin, liquid paraffin, squalane, squalene, and ceresin.

Examples of the higher fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecylenic acid, toluic acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid ( DHA) and the like.

Examples of higher alcohols include linear alcohols (eg, lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol); branched chain alcohols (eg, monostearyl glycerin ether (batyl alcohol) ), 2-decyltetradecinol, lanolin alcohol, cholesterol, phytosterol, hexyl decanol, isostearyl alcohol, octyldodecanol, and the like.

Synthetic ester oils include, for example, isopropyl myristate, cetyl octanoate, cetyl 2-ethylhexanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, dimethyloctane Hexyldecyl acid, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, N-alkyl monoisostearate Glycol, neopentyl glycol dicaprate, diisostearyl malate, glycerin di-2-heptylundecanoate, tri-2-ethylhexane Trimethylolpropane, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, glycerin tri-2-ethylhexanoate, glycerin trioctanoate, glycerin triisopalmitate, trimethylolpropane triisostearate, palmitic acid 2 -Ethylhexyl, glyceryl trimyristate, tri-2-heptylundecanoic acid glyceride, castor oil fatty acid methyl ester, oleyl oleate, acetoglyceride, 2-heptylundecyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid 2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, 2-heristyl myristate Shirudeshiru, palmitic acid 2-hexyl decyl, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, and triethyl citrate. Of these, neopentyl glycol dicaprate is preferred.

Examples of liquid oils include linseed oil, camellia oil, macadamia nut oil, corn oil, mink oil, olive oil, avocado oil, sasanqua oil, castor oil, safflower oil, jojoba oil, sunflower oil, almond oil, rapeseed oil, sesame oil. , Soybean oil, peanut oil, triglycerin, glycerin trioctanoate, glycerin triisopalmitate and the like.

Examples of the silicone oil include chain silicones such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane, and cyclic silicones such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. There is.

(D) The organic solvent may be a gel-forming polymer or polymer mixture (that is, a copolymer (A) or a mixture of a copolymer (A) and a copolymer (B)). Can be used without any particular limitation. For example, alcohol solvents, ether solvents, ketone solvents and the like are suitable, and polar solvents (for example, ethyl acetate, tetrahydrofuran and the like) can also be used.

Examples of the alcohol solvent include lower monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol, propylene glycol, glycerin, 1,3- Examples include polyhydric alcohols such as butanediol. Examples of ether solvents include diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone. The organic solvent is preferably an alcohol solvent, and more preferably ethanol.

The organic solvent can use 1 type (s) or 2 or more types.
When using an organic solvent, add the organic solvent to the gel-forming polymer or polymer mixture (that is, the copolymer (A) or the mixture of the copolymer (A) and the copolymer (B)) and mix. Then, (b) water and (c) oily components are added to prepare a liquid composition of emulsion (O / W emulsion).

The skin adhesive gel can be formed by bringing the adhesive material for skin of the present invention into contact with the skin. That is, when the adhesive material for skin of the present invention is applied to the skin, water partially volatilizes or penetrates into the skin, and the overall composition ratio changes, so that the monomer unit (I) of the copolymer is changed. The polyalkylene glycol skeletons in the side chains are cross-linked through water to gel and stay on the skin. Moreover, the branched alkyl group in the side chain of the monomer unit (II) in the copolymer exhibits affinity with the skin and imparts skin adhesiveness. Further, when the copolymer has a monomer unit (III), the linear alkyl group in the side chain of the monomer unit (III) suppresses the stickiness of the hydrogel. Is obtained.

Therefore, according to the present invention, a hydrogel that is liquid before application to the skin but has excellent adhesion to the skin surface on the skin and good adhesion to the skin (preferably the skin surface). It is possible to realize an adhesive material for skin that is excellent in adhesiveness to the skin, has good persistence of adhesion to the skin, and changes to a sticky hydrogel).

In addition, the adhesive material for skin (liquid composition) of the present invention can be appropriately mixed with additives in addition to the water, the oil component and the organic solvent. For example, examples of the additive include other polymers, alcohol solvents, surfactants, preservatives, and the like, which can be freely blended.

The blending composition of the adhesive material for skin (liquid composition) of the present invention is not particularly limited, but preferred specific examples include the following blending compositions.
Gel-forming polymer or polymer mixture: 2 to 40% by mass (preferably 5 to 20% by mass),
Water: 20 to 95% by mass (preferably 30 to 90% by mass),
Oil component: 1 to 60% by mass (preferably 2 to 50% by mass),
Organic solvent: 2 to 40% by mass (preferably 5 to 20% by mass),
Additive: 0-50% by mass (preferably 0-10% by mass)

The adhesive material for skin of the present invention is suitable as a base for external preparations for skin, such as cosmetics and external preparations for skin. Examples of bases for cosmetics include basic cosmetics such as moisturizing sheets, whitening sheets, wrinkle-stretching sheets, exfoliating sheets, body moisturizing sheets, body whitening agents, and sunburn treatments. In the case of these cosmetic bases, additives include polyhydric alcohols such as glycerin, propylene glycol, dipropylene glycol, and 1,3-butanediol; lower alcohols such as ethanol and propanol; sorbitol, xylitol, Sugars such as mannitol; preservatives such as paraben, phenoxyethanol, chlorhexidine gluconate; antioxidants such as tocopherol and its derivatives, butylhydroxytoluene, pyrosulfite; ultraviolet absorbers such as paraaminobenzoic acid derivatives and benzophenone derivatives; polyethylene glycol Moisturizers such as hyaluronic acid; vitamin C derivatives such as vitamin C and ascorbic acid-2-glucoside; whitening agents such as arbutin and kojic acid; exfoliating agents such as urea, lactic acid and citric acid; Anti-inflammatory agents such as humic acid, allantoin and glycyrrhizinate; pH adjusters such as potassium hydroxide (KOH), citrate and acetate; chelating agents; fragrances; amino acids and amino acid salts; collagen; pigments; Medicinal components such as ginseng extract and sterol glycosides; inorganic salts such as sodium salt, calcium salt and potassium salt; powders such as talc, silica gel, zinc oxide and titanium oxide are suitable.

When the adhesive material for skin of the present invention is used as a base for external preparations for skin, for example, a wound / burn protection sheet containing an osmotic pressure adjusting agent such as salt, a heat-treatment sheet containing ethanol or menthol, an antihistamine Anti-pruritic agent with antibacterial and antibiotics, anti-inflammatory agent with anti-inflammatory agent, anti-inflammatory agent with anti-fungal agent, and anthesis drug It is suitable as.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 Synthesis of Copolymer 1 1.15 g (5.0 mmol) of dimethyl 2,2′-azobisisobutyrate (manufactured by Wako Pure Chemical Industries, Ltd.) purified by recrystallization from methanol in a 500 mL round bottom flask. ), 26.0 g (80 mmol) of isostearyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd., acrylate ester whose alcohol residue is a branched alkyl group of the formula (4)) purified by removing the polymerization inhibitor in advance with hexane, Then, 22.2 g (20 mmol) of polyethylene glycol methacrylate having a degree of polymerization of 23 (Blenmer 1000, manufactured by NOF Corporation) and 197.2 g of dehydrated ethanol, which were purified by removing the polymerization inhibitor in advance, were added under a nitrogen atmosphere. The mixture was heated and stirred at 75 ° C. for 120 minutes. Thereafter, ethanol is concentrated by drying under reduced pressure to form a monomer unit (x) having a polyethylene glycol skeleton in the side chain and a monomer unit (y) having a branched alkyl group of the formula (4) in the side chain. A copolymer 1 having a content ratio (x: y) of 2: 8 in molar ratio was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) = 37681, the number average molecular weight (Mn) = 14775, and the polydispersity (Mw / Mn) = 2.554.

Example 2 Synthesis of Copolymer 2 1.15 g (5.0 mmol) of dimethyl 2,2′-azobisisobutyrate (manufactured by Wako Pure Chemical Industries, Ltd.) purified by recrystallization from methanol in a 500 mL round bottom flask. ), 16.2 g (50 mmol) of isostearyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd., acrylate ester whose alcohol residue is a branched alkyl group of the formula (4)) purified by removing the polymerization inhibitor in advance with hexane, And 55.5 g (50 mmol) of polyethylene glycol methacrylate having a degree of polymerization of 23 (manufactured by NOF Corporation, Blenmer 1000) and 291.5 g of dehydrated ethanol were added and purified under a nitrogen atmosphere. The mixture was heated and stirred at 75 ° C. for 120 minutes. Thereafter, ethanol is concentrated by drying under reduced pressure to form a monomer unit (x) having a polyethylene glycol skeleton in the side chain and a monomer unit (y) having a branched alkyl group of the formula (4) in the side chain. A copolymer 2 having a molar ratio (x: y) of 5: 5 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) = 89139, the number average molecular weight (Mn) = 32508, and the polydispersity (Mw / Mn) = 2.742.

Reference Example 1: Synthesis of Copolymer 3 1.15 g (5.0 mmol) of dimethyl 2,2′-azobisisobutyrate (manufactured by Wako Pure Chemical Industries, Ltd.) purified by recrystallization from methanol in a 500 mL round bottom flask. ), 30.4 g (80 mmol) of stearyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd., alcohol residue consisting of n-octadecyl) purified by removing the polymerization inhibitor in advance with hexane, reprecipitated with hexane and polymerized. 11.1 g (10 mmol) of polyethylene glycol methacrylate having a degree of polymerization of 23 having been removed by purifying the inhibitor in advance (Nihon Co., Ltd., Blenmer 1000) and 170.9 g of dehydrated ethanol were added, and 75 ° C. for 120 minutes in a nitrogen atmosphere. Heating and stirring were performed. Thereafter, ethanol is concentrated by drying under reduced pressure, whereby the content ratio of the monomer unit (x) having a polyethylene glycol skeleton in the side chain and the monomer unit (z) having an n-octadecyl group in the side chain ( Copolymer 3 having a molar ratio of x: z) of 1: 9 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) = 17457, the number average molecular weight (Mn) = 10243, and the polydispersity (Mw / Mn) = 1.704.

Reference Example 2: Synthesis of copolymer 4 1.15 g (5.0 mmol) of dimethyl 2,2′-azobisisobutyrate (manufactured by Wako Pure Chemical Industries, Ltd.) purified by recrystallization from methanol in a 500 mL round bottom flask. ), 17.0 g (50 mmol) of stearyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., methallylic acid ester whose alcohol residue is n-octadecyl) purified by removing the polymerization inhibitor in advance with hexane, reprecipitated with hexane, and polymerized. 55.5 g (50 mmol) of polyethylene glycol methacrylate having a degree of polymerization of 23 obtained by removing the inhibitor in advance and purifying the polymer (Blenmer 1000, manufactured by NOF Corporation) and 294.3 g of dehydrated ethanol were added, and 75 ° C. for 120 minutes in a nitrogen atmosphere. Heating and stirring were performed. Thereafter, ethanol is concentrated by drying under reduced pressure, whereby the content ratio of the monomer unit (x) having a polyethylene glycol skeleton in the side chain and the monomer unit (z) having an n-octadecyl group in the side chain ( A copolymer 4 having a molar ratio of x: z) of 5: 5 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) was 78423, the number average molecular weight (Mn) was 38802, and the polydispersity (Mw / Mn) was 2.016.

Example 3
Copolymer 1 with x: y = 2: 8 and the same amount of ethanol were added to a test tube, heated to 60 ° C. with a hot stirrer, and hand-stirred with a spatula for 10 minutes to make uniform. Further, neopentyl glycol dicaprate was added as an oil component with stirring, and purified water was further added, followed by manual stirring for 30 minutes to prepare a sample. Copolymer 1 and ethanol, an oil component, and purified water were mixed at various ratios, and the shape of the obtained dispersion liquid was visually confirmed. The white turbid solution was emulsified, the dispersion did not fall even when the test tube was turned upside down, the gel state, and the oily component discharged from the emulsion was judged as phase separation, and a phase diagram (Fig. 1) was created. .

Example 4
Copolymer 2 of x: y = 5: 5 and the same amount of ethanol were added to a test tube, heated to 60 ° C. with a hot stirrer, and hand-stirred with a spatula for 10 minutes to make uniform. Further, neopentyl glycol dicaprate was added as an oil component with stirring, and purified water was further added, followed by manual stirring for 30 minutes to prepare a sample. Copolymer 2 and ethanol, an oil component, and purified water were mixed at various ratios, and the shape of the obtained dispersion was visually confirmed. The white turbid solution was emulsified, the dispersion did not fall even when the test tube was inverted, the gel state, and the oily component discharged from the emulsion was judged as phase separation, and a phase diagram (Fig. 2) was created. .

Example 5
A copolymer 1 of x: y = 2: 8 and a copolymer 3 of x: z = 1: 9 were mixed at a mass part ratio of 1: 1, and the same mass part of ethanol was added to the test tube. The mixture was heated to 60 ° C. and hand-stirred with a spatula for 10 minutes to make uniform. Further, neopentyl glycol dicaprate was added as an oil component with stirring, and purified water was further added, followed by manual stirring for 30 minutes to prepare a sample. Copolymer 1, copolymer 3 and ethanol, an oil component, and purified water were mixed at various ratios, and the shape of the obtained dispersion liquid was visually confirmed. The white turbid solution was emulsified, the dispersion did not fall even when the test tube was inverted, the gel state, and the oily component discharged from the emulsion was judged as phase separation, and a phase diagram (Fig. 3) was created. .

Example 6
Copolymer 2 of x: y = 5: 5 and copolymer 4 of x: z = 5: 5 were mixed at a mass part ratio of 1: 1, ethanol of the same mass part was added to the test tube, and a hot stirrer was added. The mixture was heated to 60 ° C. and hand-stirred with a spatula for 10 minutes to make uniform. Further, neopentyl glycol dicaprate was added as an oil component with stirring, and purified water was further added, followed by manual stirring for 30 minutes to prepare a sample. Copolymer 2, Copolymer 4 and ethanol, an oil component, and purified water were mixed at various ratios, and the shape of the resulting dispersion was visually confirmed. The white turbid solution was emulsified, the dispersion did not fall even when the test tube was inverted, the gel state, and the oily component discharged from the emulsion was judged as phase separation, and a phase diagram (Fig. 4) was created. .

From the results of Examples 3 to 6, the compositions containing the copolymers prepared in Examples 3 to 6 were the same component and were in an oil-in-water emulsified state, an oil-in-water gel state, and phase separation. It can be seen that there are three states. This is because it is liquid in the emulsified state, and spreads and adheres to the skin surface corresponding to the unevenness of the skin surface. When the composition changes due to partial evaporation of moisture or penetration into the skin, the gel state (hydrogel ).

Comparative Example 1: Synthesis of Copolymer 5 1.15 g (5.0 mmol) of dimethyl 2,2′-azobisisobutyrate (manufactured by Wako Pure Chemical Industries, Ltd.) purified by recrystallization from methanol in a 500 mL round bottom flask. ), 9.5 g (95 mmol) of methyl methacrylate (manufactured by Tokyo Kasei Kogyo Co., Ltd.), which was reprecipitated with hexane and purified by removing the polymerization inhibitor in advance, was reprecipitated with hexane, and purified by removing the polymerization inhibitor in advance. 5.5 g (5 mmol) of polyethylene glycol methacrylate having a polymerization degree of 23 (manufactured by NOF Corporation, Blemmer 1000) and 64.8 g of dehydrated ethanol were added, and the mixture was heated and stirred at 75 ° C. for 120 minutes in a nitrogen atmosphere. Then, the copolymer 5 was obtained by concentrating ethanol by drying under reduced pressure. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) was 24909, the number average molecular weight (Mn) was 13209, and the polydispersity (Mw / Mn) was 1.886.

The above synthesized copolymer 5 and the same amount of ethanol were added to a test tube, heated to 60 ° C. with a hot stirrer, and stirred manually for 10 minutes with a spatula to make uniform. Further, neopentyl glycol dicaprate was added as an oil component with stirring, and purified water was further added, followed by manual stirring for 30 minutes to prepare a sample. Copolymer 5 and ethanol, an oil component, and purified water were mixed at various ratios, and the shape of the obtained dispersion was visually confirmed. The white turbid solution was emulsified, the dispersion did not fall even when the test tube was inverted, the gel state, and the oily component discharged from the emulsion was judged as phase separation, and a phase diagram (Fig. 5) was created. .

The copolymer 5 of Comparative Example 1 is a copolymer comprising 5 mol% of monomer units having a polyethylene glycol skeleton in the side chain and 95 mol% of monomer units having a methyl group in the side chain. A copolymer in which the monomer unit having a branched alkyl group in the compounds 1, 2 and the like is replaced with a monomer unit having a methyl group in the side chain, and the content of the monomer unit having a polyethylene glycol skeleton is suppressed. Although there were only oil-in-water type (O / W type) emulsion, oil-in-water type (O / W type) emulsion, and transparent solution that were easy to separate, no gel was formed. Therefore, in order for the liquid composition applied to the skin to become a gel on the skin and adhere to the skin, it is necessary that the side chain of the copolymer has an appropriate polyethylene glycol skeleton together with a branched alkyl group. It has been shown.

[Evaluation of stickiness]
An appropriate amount of the liquid composition having the composition (prescription) shown in Table 1 below was applied to the skin without disclosing the composition, the stickiness was evaluated, and the order in which the stickiness was felt was determined.

The formulation 1 containing the copolymer 1 having a high content of monomer units having a branched alkyl group in the side chain was evaluated as having the most stickiness. From the comparison between Formulation 3 in which copolymer 3 containing a monomer unit having a linear alkyl group in the side chain is added to Formulation 1 and Formulation 2 and Formulation 4, the side chain has a linear alkyl group. When a copolymer containing monomer units was blended, stickiness was suppressed.

[Tack test]
The stickiness scale was mechanically evaluated by a tack test.
A liquid composition having a composition (prescription) shown in Table 2 below was prepared, and 10 μL was applied to the inner side of the forearm in a range of 2 cm × 2 cm. After application, it was dried with cold air for 3 minutes. Measurement was performed in a handy love tester tack test mode, and bioskin was affixed to the contact. The operation of applying the contact to the coated portion for 2 seconds and releasing the contact was repeated 12 times, and the average of the obtained stress results was calculated.

Copolymer 1 containing a monomer unit having a polyethylene glycol skeleton in the side chain and a copolymer unit 1 having a monomer unit having a branched alkyl group in the side chain and a monomer unit having a linear alkyl group in the side chain It was confirmed that when the coalescence 3 was blended, the peeling stress was reduced. From this, it was recognized that the copolymer having a linear alkyl group in the side chain suppresses stickiness.

A dispersion of a copolymer containing a monomer unit having a polyalkylene glycol skeleton in the side chain and a monomer unit having a branched alkyl group in the side chain changes from liquid to gel on the skin, It is a material that adheres. Further, by copolymerizing such a copolymer with a monomer having a linear alkyl group in the side chain, or combining a copolymer containing a monomer unit having a linear alkyl group in the side chain. Can suppress stickiness on the skin. These copolymers are useful as a new base for solving the problems of existing bases, as a base for skin external preparations such as cosmetics and external medicines appropriately blended with moisturizing agents and active ingredients.

This application is based on Japanese Patent Application No. 2015-124280 filed in Japan, the contents of which are incorporated in full herein.

Claims

Copolymer comprising monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain A gel-forming polymer comprising (A).
The monomer unit (I) is a monomer unit represented by the following formula (1), and the monomer unit (II) is a monomer unit represented by the following formula (2). The polymer according to claim 1.

(Wherein R 1 represents a hydrogen atom or a methyl group, and X 1 represents —O—, —CH 2 —O—, —CO—, —CO—O—, or —CO—NR 2 —). Here, R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 3 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, A represents an alkylene group, 2 ≦ n ≦ 100 .)

(Wherein R 4 represents a hydrogen atom or a methyl group, X 2 represents —O—, —CH 2 —O—, —CO—, or —CO—O—, and R 5 represents 3 carbon atoms) Represents 30 to 30 branched alkyl groups.)
The polymer according to claim 2, wherein the oxyalkylene group represented by AO in the formula (1) is an ethylene oxide group.
The branched alkyl group having 3 to 30 carbon atoms represented by R 5 in the formula (2) is any one of groups represented by the following formulas (4) to (6). Polymer.
The copolymer ratio a1 ((1) :( 2)) of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (2) in the copolymer (A) is 5:95. The polymer according to any one of claims 2 to 4, which has a molar ratio of ˜90: 10.
The polymer according to any one of claims 1 to 4, wherein the copolymer (A) further comprises a monomer unit (III) having a linear alkyl group having 3 to 30 carbon atoms in the side chain.
The polymer according to claim 6, wherein the monomer unit (III) is a monomer unit represented by the following formula (3).

(Wherein R 6 represents a hydrogen atom or a methyl group, X 3 represents —O—, —CH 2 —O—, —CO—, or —CO—O—, and R 7 represents 3 carbon atoms) Represents a linear alkyl group of ˜30.)
Copolymer ratio a2 of the monomer unit represented by Formula (1), the monomer unit represented by Formula (2), and the monomer unit represented by Formula (3) in the copolymer (A) ((1) :( 2) :( 3)) is 5 to 60:10 to 90: 5 to 50 (molar ratio) (however, the sum of the numerical values of (1), (2) and (3) is 100) 8. The polymer of claim 7, wherein
Copolymer comprising monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and monomer unit (II) having a branched alkyl group having 3 to 30 carbon atoms in the side chain (A) and
Copolymer containing a monomer unit (I) having a polyalkylene glycol skeleton having a polymerization degree of 2 to 100 in the side chain and a monomer unit (III) having a linear alkyl group having 3 to 30 carbon atoms in the side chain A gel-forming polymer mixture comprising the coalescence (B).
The monomer unit (I) is a monomer unit represented by the following formula (1), the monomer unit (II) is a monomer unit represented by the following formula (2), The polymer mixture according to claim 9, wherein the monomer unit (III) is a monomer unit represented by the following formula (3).

(Wherein R 1 represents a hydrogen atom or a methyl group, and X 1 represents —O—, —CH 2 —O—, —CO—, —CO—O—, or —CO—NR 2 —). Here, R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 3 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, A represents an alkylene group, 2 ≦ n ≦ 100 .)

(Wherein R 4 represents a hydrogen atom or a methyl group, X 2 represents —O—, —CH 2 —O—, —CO—, or —CO—O—, and R 5 represents 3 carbon atoms) Represents 30 to 30 branched alkyl groups.)

(Wherein R 6 represents a hydrogen atom or a methyl group, X 3 represents —O—, —CH 2 —O—, —CO—, or —CO—O—, and R 7 represents 3 carbon atoms) Represents a linear alkyl group of ˜30.)
The polymer mixture according to claim 10, wherein the oxyalkylene group represented by AO in the formula (1) is an ethylene oxide group.
12. The branched alkyl group having 3 to 30 carbon atoms represented by R 5 in the formula (2) is any one of groups represented by the following formulas (4) to (6). Polymer blends.
The copolymerization ratio a3 ((1) :( 2)) of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (2) in the copolymer (A) is 1:99. ~ 90: 10 (molar ratio), and the copolymerization ratio b1 of the monomer unit represented by the formula (1) and the monomer unit represented by the formula (3) in the copolymer (B) (( The polymer mixture according to any one of claims 10 to 12, wherein 1) :( 3)) is from 1:99 to 90:10 (molar ratio).
(A) the polymer or polymer mixture according to any one of claims 1 to 13,
A liquid composition comprising (b) water, and (c) an oil component,
An adhesive material for skin that turns into a gel on the skin.
Furthermore, the adhesive material for skin of Claim 14 containing the organic solvent further (d).
The material according to claim 14 or 15, which is used as a base for an external preparation for skin.
The material according to claim 16, wherein the external preparation for skin is a cosmetic.
The material according to claim 16, wherein the external preparation for skin is an external preparation for skin.
A method for forming a skin adhesive gel, comprising bringing the skin adhesive material according to claim 14 or 15 into contact with the skin.