JP4133740B2 - Composition for scalp and hair - Google Patents

Description

  The present invention relates to a composition for scalp and hair containing a thickener comprising a microgel. More specifically, the present invention relates to a composition for scalp and hair containing a microgel that exhibits an excellent thickening effect and an excellent usability. In particular, the present invention relates to a composition for scalp and hair that exhibits an excellent thickening effect even in a scalp and hair cosmetic with a high blend of ethanol.

  Many scalp and hair compositions are liquid products that spread easily to the scalp and hair, but if the scalp and hair composition is applied, it will be difficult to get the desired effect by dripping from the application site and getting into the eyes during use. It has been a problem that the amount of money that has fallen due to the blood circulation promoting effect becomes red. In particular, when applied to the hairline of the temporal region or the frontal region, it is easy to sag. Therefore, many attempts have been made to give the scalp and hair composition a viscosity.

  Among these, water-soluble thickeners that can be used in the scalp and hair composition include various polysaccharides, natural polymers such as gelatin, synthetic polymers such as polyoxyethylene and crosslinked poly (meth) acrylic acid, Examples thereof include inorganic minerals such as montmorillonite and silica.

  On the other hand, the most widely used thickener for cosmetics is a polymer of acrylic acid collectively called carboxyvinyl polymer. The trade names are Hibiswako (Wako Pure Chemicals), Shintalen (3V SIGMA), Carbon It is commercially available as Paul (Goodrich). These thickeners are chemically cross-linked polymers (The B.F. Goodrich Company, Specialty Polymers and Chemical Div., Carbopol Data Sheets and Applications Literature). Since it is inexpensive, has a high thickening effect, and gels in a small amount, it is frequently used as a water-soluble thickener or stabilizer in the pharmaceutical and cosmetic industries, particularly in cosmetics. Such an aqueous dispersion of a crosslinked polymer has a very high thickening effect and is widely used as a thickener for cosmetics or daily goods (see Non-Patent Document 1). Barry, BW and Meyer MC Int. J. Pharm 2 : 1 (1979). Hydroxypropyl cellulose is also frequently used as a nonionic thickener.

  However, the carboxyvinyl polymer has a problem that the pH range in which the viscosity can be increased is limited. In the carboxyvinyl polymer, the polymer swells and thickens in water when the carboxyl group contained in the polymer is in a dissociated state. Therefore, the carboxyvinyl polymer does not function as a thickener in a pH range of weak acidity or lower where the carboxyl group is not sufficiently dissociated, and instead of this, the development of a thickener capable of thickening over a wide pH range has been developed. The current situation is strongly desired.

  Furthermore, some cosmetic formulations have high ethanol concentrations, but at present, it is extremely difficult to efficiently thicken such formulations with conventional thickeners such as carboxyvinyl polymer and hydroxypropylcellulose. It is a problem. Carboxyvinyl polymer is inhibited from dissociation of carboxyl groups under acidic conditions of pH 5 or lower or in an aqueous solution containing salt, and the viscosity is extremely lowered to prevent gelation. For this reason, it cannot be used in a formulation that requires acidic conditions and a salt coexistence system. Moreover, pH adjustment is important for the composition for scalp and hair in which drug stability is an important point. For example, at a pH of 5 or more, a drug having an ester bond such as nicotinic acid benzyl ester which is a blood circulation promoter which is a main component of the scalp and hair composition is unstable. On the other hand, it is difficult to increase the viscosity in the stable pH range. Further, in the presence of salts, it is necessary to greatly increase the blending amount in order to maintain the thickening effect, and as a result, the usability is significantly impaired. That is, when applied to the scalp and hair, a sticky feeling is produced, and this sticky feeling becomes a very serious problem in terms of the usability of the scalp hair composition.

  In order to solve this problem, a copolymer of acrylamide alkyl sulfonic acid and (meth) acrylic acid (Patent Document 1), a copolymer of acrylamide alkyl sulfonic acid and an alkyl group-containing unsaturated monomer (Patent Document) 2) Or a homopolymer of 2-acrylamido-2-methylpropanesulfonic acid (Patent Document 3) is applied to cosmetics.

  However, although the polymer having an acrylamide alkyl sulfonic acid in the skeleton has improved acid resistance and can be used in a formulation requiring acidic conditions, a sticky feeling at the time of drying, which is considered to be derived from acrylic acid, occurs, and the thickened cosmetic. It can not be said that the usability is sufficiently satisfactory.

  In view of the above circumstances, Kaneda et al. Added a copolymer obtained by copolymerizing 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof, dialkylacrylamide and a crosslinkable monomer to a cosmetic. It has been found that satisfactory usability can be exhibited when blended as a sticking agent (Patent Document 4). This copolymer is a polymer gel (polymer gel) obtained by radical polymerization in a homogeneous polymerization system. After the polymer gel is produced, it is mechanically pulverized to form a thickener powder for scalp and hair. It is a technology for blending into products. In some cases, the polymer gel particles are large, causing problems in the appearance of the cosmetic. Furthermore, there was room for further improvement in the thickening effect.

The thickener used in the present invention is a polymer microgel produced by a polymerization method generally referred to as a reverse phase emulsion polymerization method, and is disclosed in Patent Document 4. The polymerization method and mechanical properties are different from those of a thickener made of a synthetic polymer obtained by a homogeneous polymerization system.
A microgel is a fine particle of a synthetic polymer electrolyte produced by a reverse phase microemulsion polymerization method. The thickener comprising the microgel of the present invention swells in water, ethanol or a water-ethanol mixed solution, and can provide a high-viscosity solution that is visually uniform in appearance.
The method for producing the thickener in the present invention, that is, the polymerization system of the microgel used as the thickener is different from the homogeneous polymerization system for producing the synthetic polymer which is a conventional thickener.
The synthetic polymer based on the homogeneous polymerization system disclosed in Patent Document 4 is not a microgel used in the present invention, but must be pulverized into a powder state in order to be blended into a cosmetic after polymerization. In addition, a synthetic polymer gel is noticeable and may cause problems in appearance.
On the other hand, the microgel used in the present invention is polymerized in a heterogeneous polymerization system. The resulting synthetic polymer becomes a fine polymer gel, that is, a microgel, and when blended into cosmetics, it does not need to be pulverized and powdered, exhibits an excellent thickening effect and excellent usability. Furthermore, the appearance of the cosmetic is also preferable.

As for the reverse phase emulsion polymerization method of a polymer, Patent Document 5 describes a technique of producing a water-swellable polymer using acrylic acid by reverse phase polymerization and applying it as a thickener. However, this is different from the microgel used in the present invention, which improves the shortcomings of the currently widely used carboxyvinyl polymers.
Patent Document 6 discloses that microgel particles of a water-absorbing resin are produced in a certain size or more so as to be suitable for diapers or sanitary products, but this can be applied to a cosmetic thickener. It is not a technique and is completely different from the microgel used in the present invention.

JP-A-9-157130 JP-A-10-279636 JP-A-10-67640 JP-A-2001-114641 Japanese Patent No. 1911623 Japanese Patent Laid-Open No. 9-12613 Barry, BW and Meyer MC Int. J. Pharm 2: 1 (1979)

As a result of intensive studies in view of the above-mentioned circumstances, the present inventors have surprisingly found that a microgel comprising a synthetic polymer electrolyte produced by a specific reverse phase emulsion polymerization solves the above-mentioned problems and has an extremely excellent thickening property. The inventors have found that the effects and usability are exhibited, and have completed the present invention.
And the thickener comprising this microgel is the most preferable thickener for the scalp hair composition because it exhibits an excellent thickening effect even in cosmetics for scalp and hair, especially those containing high amounts of ethanol. I found it.
The present invention is used for the use of a thickener for blending a microgel comprising a synthetic polymer electrolyte produced by a specific reverse phase emulsion polymerization (reverse phase microemulsion polymerization) into a scalp and hair composition. It is possible to provide a composition for scalp and hair containing a polymer gel composed of a synthetic polyelectrolyte produced by a synthetic method or a reverse phase suspension polymerization method, and a new type of thickener that solves the disadvantages of carboxyvinyl polymer. .

（Ｒ₁はＨまたはメチル基、Ｒ₂及びＲ₃はそれぞれ独立にメチル基、エチル基、プロピル基、イソプロピル基を表わす。）

一般式（２）

（Ｒ₄及びＲ₅はそれぞれ独立にＨ又はメチル基、Ｒ₆は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｘは金属イオン若しくはＮＨ₃を表わす。）

一般式（３）

（Ｒ₇はＨ又はメチル基、Ｒ₈はＨまたは炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₉は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₁₀、Ｒ₁₁、Ｒ₁₂はメチル基またはエチル基、Ｙはクロライドのイオンを表わす。） That is, the present invention is a composition in which an organic solvent or oil is used as a dispersion medium and water is used as a dispersion phase, and by using a surfactant, the polymerization system in the reverse-phase emulsion polymerization is changed to a single-phase microemulsion or fine W / O. A composition for scalp and hair containing a thickener consisting of a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer in a dispersed phase and radical polymerization in the dispersed phase under the conditions for forming an emulsion, and ethyl alcohol. Wherein the water-soluble ethylenically unsaturated monomer is
A dialkylacrylamide represented by the following general formula (1):
Formulating an anionic acrylamide derivative represented by the following general formula (2) or a cationic acrylamide derivative represented by the following general formula (3) with a thickener powder:
A composition for scalp and head hair, wherein the content of the ethyl alcohol is 20 to 90% by mass and the thickener comprising the microgel is 0.01 to 10% by mass with respect to the total amount of the composition. It is to provide.
General formula (1)

(R ₁ represents H or a methyl group, and R ₂ and R ₃ each independently represents a methyl group, an ethyl group, a propyl group, or an isopropyl group.)

General formula (2)

(R ₄ and R ₅ each independently represent H or a methyl group, R ₆ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a metal ion or NH _3. )

General formula (3)

(R ₇ is H or a methyl group, R ₈ is H or a linear or branched alkyl group having 1 to 6 carbon atoms, R ₉ is a linear or branched alkyl group having 1 to 6 carbon atoms, R ₁₀ , R ₁₁ and R ₁₂ represent a methyl group or an ethyl group, and Y represents a chloride ion.)

（Ｒ₁はＨまたはメチル基、Ｒ₂及びＲ₃はそれぞれ独立にメチル基、エチル基、プロピル基、イソプロピル基を表わす。）

一般式（２）

（Ｒ₄及びＲ₅はそれぞれ独立にＨ又はメチル基、Ｒ₆は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｘは金属イオン若しくはＮＨ₃を表わす。）

一般式（３）

（Ｒ₇はＨ又はメチル基、Ｒ₈はＨまたは炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₉は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₁₀、Ｒ₁₁、Ｒ₁₂はメチル基またはエチル基、Ｙはクロライドのイオンを表わす。）

一般式（４）

The present invention also provides a composition comprising an organic solvent or an oil as a dispersion medium and water as a dispersed phase, whereby the polymerization system in the reverse phase emulsion polymerization is a one-phase microemulsion or fine W / O by using a surfactant. A composition for scalp and hair containing a thickener consisting of a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer in a dispersed phase and radical polymerization in the dispersed phase under the conditions for forming an emulsion, and ethyl alcohol. Wherein the water-soluble ethylenically unsaturated monomer is
A dialkylacrylamide represented by the following general formula (1):
An anionic acrylamide derivative represented by the following general formula (2) or a cationic acrylamide derivative represented by the following general formula (3);
Formulating a thickener powder that is a crosslinking monomer represented by the following general formula (4),
A composition for scalp and head hair, wherein the content of the ethyl alcohol is 20 to 90% by mass and the thickener comprising the microgel is 0.01 to 10% by mass with respect to the total amount of the composition. It is to provide.
General formula (1)

(R ₁ represents H or a methyl group, and R ₂ and R ₃ each independently represents a methyl group, an ethyl group, a propyl group, or an isopropyl group.)

General formula (2)

(R ₄ and R ₅ each independently represent H or a methyl group, R ₆ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a metal ion or NH _3. )

General formula (3)

(R ₇ is H or a methyl group, R ₈ is H or a linear or branched alkyl group having 1 to 6 carbon atoms, R ₉ is a linear or branched alkyl group having 1 to 6 carbon atoms, R ₁₀ , R ₁₁ and R ₁₂ represent a methyl group or an ethyl group, and Y represents a chloride ion.)

General formula (4)

  Furthermore, this invention provides said scalp hair composition characterized by content of the said ethyl alcohol being 60 mass% or more with respect to the composition whole quantity.

  The present invention further provides the composition for scalp and hair described above, which further comprises a hair-restoring agent.

  Furthermore, the present invention further includes one or two selected from the group consisting of blood circulation promoters, 5α-reductase inhibitors, follicular hormones, local stimulants, antibacterial agents, antiseborrheic agents, anti-inflammatory agents, and hair follicle activators. The present invention provides a composition for scalp and hair described above, which contains more than seeds.

  The present invention also provides the composition for scalp and hair described above, wherein the composition has a viscosity of 10 to 10,000 mPa · s at 30 ° C.

  Furthermore, the present invention provides the composition for scalp and hair described above, wherein the composition for scalp and hair is a scalp and hair cosmetic.

  According to the present invention, there is provided a composition for scalp and hair that is excellent in feeling of use and has no sagging or stickiness. In particular, the thickener used in the present invention is a composition for scalp and hair that exhibits an excellent thickening effect and is excellent in feeling of use and has no sagging or stickiness even in cosmetics for scalp and hair that contain a high amount of ethanol. Can provide. Furthermore, the composition for scalp head hair excellent in the hair-restoration effect, the hair loss prevention effect, and the anti-dandruff and scab prevention effect can be provided.

  Hereinafter, the present invention will be described in detail.

  The thickener composed of a microgel used in the present invention is a composition having an organic solvent or oil as a dispersion medium and water as a dispersed phase, in which a water-soluble ethylenically unsaturated monomer is dissolved in the dispersed phase and radicals are formed in the dispersed phase. It is a thickener composed of a synthetic polymer microgel obtained by polymerization.

That is, a polymer microgel produced by a polymerization method generally referred to as a reverse emulsion polymerization method is used for a thickener, and is disclosed in Patent Document 4 (Japanese Patent Laid-Open No. 2001-114641). The polymerization method and mechanical properties are different from those of a thickener made of a synthetic polymer obtained by a homogeneous polymerization system.
A microgel is a fine particle of a synthetic polymer electrolyte produced by a reverse phase microemulsion polymerization method. The thickener comprising the microgel of the present invention swells in water, ethanol or a water-ethanol mixed solution, and can provide a high-viscosity solution that is visually uniform in appearance.

The method for producing the thickener in the present invention, that is, the polymerization system of the microgel used as the thickener is different from the homogeneous polymerization system for producing the synthetic polymer which is a conventional thickener.
The synthetic polymer based on the homogeneous polymerization system disclosed in Patent Document 4 is not a microgel used in the present invention, but must be pulverized into a powder state in order to be blended into a cosmetic after polymerization of the synthetic polymer. In addition, a synthetic polymer gel is noticeable and may cause problems in appearance.
On the other hand, the microgel used in the present invention is polymerized in a heterogeneous polymerization system. The resulting synthetic polymer becomes a fine polymer gel, that is, a microgel, and when blended into cosmetics, it does not need to be pulverized and powdered, exhibits an excellent thickening effect and excellent usability. Furthermore, the appearance of the cosmetic is also preferable.

As for the reverse phase emulsion polymerization method of polymer, a water-swellable polymer using acrylic acid is produced by reverse phase polymerization in Patent Document 5 (Patent No. 1911623) and applied as a thickener. Although there is a description of the technology, this is different from the microgel used in the present invention which improves the shortcomings of carboxyvinyl polymers which are currently widely used.
Further, Patent Document 6 (Japanese Patent Laid-Open No. 9-12613) discloses that microgel particles of a water-absorbing resin are produced in a certain size or more so as to be suitable for diapers or sanitary products. Is not a technology that can be applied to a cosmetic thickener and is completely different from the microgel used in the present invention.

The thickener used in the present invention is produced by a reverse phase emulsion polymerization method. That is, in a composition having an organic solvent or an oil as a dispersion medium and water as a dispersed phase, it is produced by dissolving a water-soluble ethylenically unsaturated monomer in the dispersed phase and radical polymerization in the dispersed phase. The polymerized microgel is washed and dried, but need not be crushed.
In particular, by using a surfactant adjusted to an appropriately selected hydrophilic / hydrophobic balance (HLB), the microgel under the condition that the polymerization system in the inverse emulsion polymerization forms a one-phase microemulsion or a fine W / O emulsion. It is preferred that a thickener consisting of

  A single-phase microemulsion is a state in which the oil phase and the water phase coexist thermodynamically and the interfacial tension between the oil and water is minimized. The fine W / O emulsion is thermodynamically unstable, but oil and water are present as fine W / O emulsions stably in kinetics. Generally, the particle diameter of the inner aqueous phase of the fine W / O emulsion is about several tens to 100 nm. These states are determined only by the composition and temperature of the system and do not depend on mechanical stirring conditions.

The composition constituting the polymerization system is composed of an organic solvent or oil that does not mix with water (dispersing medium constituting the outer phase) and a dispersed phase consisting of water (constituting the inner phase).
Preferable organic solvents include alkanes such as pentane, hexane, heptane, octane, nonane, decane, undecane; cycloalkanes such as cyclopentane, cyclohexane, cycloheptane, cyclooctane; benzene, toluene, xylene, decalin, naphthalene, etc. And aromatic and cyclic hydrocarbons.
Preferred oils include nonpolar oils such as paraffin oil.
The water-soluble ethylenically unsaturated monomer is dissolved in water as a dispersed phase, then mixed with an organic solvent or oil as a dispersion medium, heated to a desired temperature, and then a polymerization initiator is added to the aqueous phase for polymerization. .

  In general, in the heterogeneous polymerization method, it is known that the properties of the polymer produced vary depending on the stirring conditions during the polymerization. The reason is that since the emulsification system is not thermodynamically stable, the shape and size of the emulsified particles change depending on the stirring conditions. In the present invention, it has been found that these problems can be avoided by performing polymerization in a thermodynamically stable one-phase microemulsion region or a fine W / O emulsion region that exists in the vicinity of a metastable one-phase region. It was. Specifically, the composition of the polymerization system (type of organic solvent, so that the above-mentioned one-phase microemulsion or fine W / O emulsion region appears in the vicinity of the optimum polymerization temperature of the polymerization initiator for normal thermal polymerization or redox polymerization. By adjusting the surfactant (HLB), it became possible to obtain a microgel with a high thickening effect by polymerizing the polymer in a fine aqueous phase (water droplets).

A phase diagram example is shown in FIG. FIG. 1 is a three-component phase diagram of hexane (indicated by W) / surfactant / water-soluble ethylene monomer aqueous solution (indicated by O) when hexane is used as the organic solvent. The region A shown in the figure is a one-phase microemulsion region to a fine W / O emulsion region, and by performing polymerization in this region, preferable microgel polymerization is possible.
In contrast, conventional polymer thickeners based on suspension polymerization (for example, the method described in Patent Document 4) have difficulty in controlling the particle size of water droplets during polymerization, and it is difficult to obtain good-quality microgels. is there.

（Ｒ₁はＨまたはメチル基、Ｒ₂及びＲ₃はそれぞれ独立にメチル基、エチル基、プロピル基、イソプロピル基を表わす。） The water-soluble ethylenically unsaturated monomer is preferably a combination of a nonionic monomer and an ionic monomer (anionic monomer or cationic monomer).
The nonionic monomer is preferably a dialkylacrylamide represented by the general formula (1).
General formula (1)

(R ₁ represents H or a methyl group, and R ₂ and R ₃ each independently represents a methyl group, an ethyl group, a propyl group, or an isopropyl group.)

（Ｒ₄及びＲ₅はそれぞれ独立にＨ又はメチル基、Ｒ₆は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｘは金属イオン若しくはＮＨ₃を表わす。）
一般式（３）

（Ｒ₇はＨ又はメチル基、Ｒ₈はＨまたは炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₉は炭素原子数１〜６の直鎖若しくは分岐のアルキル基、Ｒ₁₀、Ｒ₁₁、Ｒ₁₂はメチル基またはエチル基、Ｙはクロライドのイオンを表わす。）
The ionic monomer is preferably an anionic acrylamide derivative represented by the general formula (2) or a cationic acrylamide derivative represented by the general formula (3).
General formula (2)

(R ₄ and R ₅ each independently represent H or a methyl group, R ₆ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a metal ion or NH _3. )
General formula (3)

(R ₇ is H or a methyl group, R ₈ is H or a linear or branched alkyl group having 1 to 6 carbon atoms, R ₉ is a linear or branched alkyl group having 1 to 6 carbon atoms, R ₁₀ , R ₁₁ and R ₁₂ represent a methyl group or an ethyl group, and Y represents a chloride ion.)

Particularly preferred dialkylacrylamides are dimethylacrylamide and diethylacrylamide.
Particularly preferred ionic acrylamide derivatives are 2-acrylamide 2-methylpropanesulfonic acid and its salts.
A particularly preferred cationic acrylamide derivative is N, N, -dimethylaminopropylacrylamide methyl chloride.

  The monomer composition ratio in the polymerization system of the nonionic monomer and the ionic monomer (the charge ratio of the polymerization system) is arbitrarily determined arbitrarily according to the monomer composition ratio of the target microgel. The monomer composition ratio of the microgel and the charging ratio to the polymerization system are almost the same. The charging ratio (molar ratio) of the polymerization system of the nonionic monomer and the ionic monomer is usually nonionic monomer: ionic monomer = 0.5: 9.5 to 9.5: 0.5, preferably 1. : 9 to 9: 1, more preferably 7: 3 to 9: 1. The optimum ratio is nonionic monomer: ionic monomer = 8: 2.

  The above-mentioned water-soluble ethylenically unsaturated monomer is arbitrarily selected and the thickener used in the present invention is polymerized. A particularly preferred thickening agent is a binary copolymer microgel copolymerized from dimethylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid as water-soluble ethylenically unsaturated monomers. In this case, there is no need for a crosslinking monomer, and a thickener that exhibits an excellent thickening effect and a feeling of use due to self-crosslinking can be obtained. A crosslinking monomer can also be used. In that case, the crosslinking monomer represented by the general formula (4) is preferable, and methylenebisacrylamide is particularly preferable.

  In order to dissolve the water-soluble ethylenically unsaturated monomer in the dispersed phase and polymerize the preferred microgel for the present invention, it is necessary to select the optimum outer phase oil or organic solvent and surfactant. . The present inventor has prepared the hydrophilic-hydrophobic balance (HLB) of a nonionic surfactant to show a cloud point at a temperature suitable for thermal radical polymerization by creating a phase diagram in the composition of the polymerization system. The present inventors have found that a microgel having a rheological property preferable as a thickener can be obtained by creating a state of forming a one-phase microemulsion or a fine W / O emulsion at a normal thermal radical polymerization temperature.

Preferred surfactants are polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene hexyl decyl ether, polyoxyethylene isostearyl ether , Polyoxyethylene octyldodecyl ether, polyoxyethylene behenyl ether, polyoxyethylene cholesteryl ether, polyoxyethylene hydrogenated castor oil, sorbitan fatty acid ester, mono fatty acid glycerin, tri fatty acid glycerin, polyglycerin fatty acid ester, isostearic acid polyoxyethylene glycerin, Polyoxyethylene glycerin triisostearate, polyoxymonostearate Ji Ren glycerin distearate, polyoxyethylene glyceryl, and the like tristearate polyoxyethylene glyceryl.
These surfactants can be appropriately combined to adjust to a desired HLB and added to the polymerization system.

  Surprisingly, in the microgel copolymerized with dialkylacrylamide and acrylamide ionic monomer, the spontaneous crosslinking reaction proceeds, especially without the polyfunctional crosslinking monomer being copolymerized as the third component. Self-crosslinked microgels are obtained, which are particularly preferred thickeners for the present invention.

Although the third component polyfunctional crosslinking monomer is not necessary, the microgel used in the present invention can be synthesized even if it is added and copolymerized. The multifunctional crosslinking monomer is preferably a monomer represented by the general formula (4), and can be crosslinked using one or more kinds of crosslinking monomers represented by the general formula (4). It is essential that these crosslinkable monomers can take a crosslinked structure efficiently in a polymerization system of dialkylacrylamide and an ionic acrylamide derivative.







General formula (4)

  Preferred crosslinkable monomers include, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyoxyethylene diacrylate, polyoxyethylene dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane triacrylate, N, N′-methylenebisacrylamide, N, N′-ethylenebisacrylamide, triallyl isocyanurate, pentaerythritol dimethacrylate, and the like can be used, and one or more selected from these can be used. In the present invention, N, N′-methylenebisacrylamide is particularly preferably used.

  The molar ratio of the content of 2-acrylamido-2-methylpropanesulfonic acid units and dialkylacrylamide units in the copolymer that is a thickener used in the present invention is usually 2-acrylamido-2-methylpropanesulfonic acid units. : Dialkylacrylamide unit = 0.5: 9.5 to 9.5: 0.5, preferably 1: 9 to 9: 1, and more preferably = 3: 7 to 1: 9. The optimum ratio is 2-acrylamido-2-methylpropanesulfonic acid unit: dialkylacrylamide unit = 2: 8. The viscosity of the thickener used in the present invention is due to the extension of the molecular chain by electrostatic repulsion based on the sulfonyl group which is a strong dissociation group and the spontaneous crosslinking reaction of dialkylacrylamide or the crosslinked structure by a crosslinking monomer, If the content of the 2-acrylamido-2-methylpropanesulfonic acid unit or a salt thereof is less than 5 mol% with respect to the dialkylacrylamide unit, sufficient molecular viscosity may not be obtained, and sufficient viscosity may not be obtained. .

  The use amount of the crosslinkable monomer is preferably in the range of 0.0001 to 2.0 mol% with respect to the total number of moles of 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof and dialkylacrylamide. Thickeners prepared at less than 0.0001 mol% may not have a crosslinking effect. Moreover, when it exceeds 2 mol%, since a crosslinking density is too high and a microgel cannot fully swell, it may not exhibit sufficient thickening effect.

The molecular weight of the microgel used as a thickener in the present invention is about 100,000 to 5,000,000 (average of PEG: measured by GPC), and is adjusted by the viscosity required as the thickener.
The microgel obtained by the above polymerization method has all the rheological properties of the following (1) to (3). The thickener composed of the microgel is obtained by the production method by the polymerization method described above, and is preferably used as a thickener.
(1) The apparent viscosity of an aqueous dispersion of 0.5% (mass percentage) of the microgel is 10,000 mPa · s or more at a shear rate of 1.0 s ⁻¹ .
(2) The apparent viscosity of the 0.5% (percentage by mass) ethanol dispersion of the microgel is 5000 mPa · s or more at a shear rate of 1.0 s ⁻¹ .
(3) The dynamic elastic modulus in a 0.5% (mass percentage) aqueous dispersion or ethanol dispersion of the microgel is G ′> G ″ within a strain of 1% or less and a frequency of 0.01 to 10 Hz.
The apparent viscosity of the water or ethanol dispersion of the microgel is a viscosity at a measurement temperature of 25 ° C. and a shear rate of 1 s ⁻¹ using a cone plate rheometer (MCR-300 manufactured by Paar Rhysica).
The dynamic elastic modulus is the value of the storage elastic modulus (G ') and loss elastic modulus (G ") measured at a measurement temperature of 25 ° C and a strain of 1% or less in the frequency range of 0.1 to 10 Hz using the same measuring device. Means.

The microgel used as a thickener in the present invention can be separated in a powder state through a simple precipitation purification step after polymerization. The microgel separated into a powder form easily disperses in water or ethanol or a mixed solvent of water / ethanol, swells quickly, and functions as a thickener.
In addition, by selecting a strongly acidic monomer (for example, a monomer containing a sulfonic acid residue) as an ionic monomer to be copolymerized with the microgel, an acidic preparation that cannot be thickened with a conventional carboxyvinyl polymer can be obtained. Thickening is also possible.
Furthermore, this microgel can also be used to thicken or gel alcohol, which has been conventionally difficult to thicken or gel. In particular, it exhibits an excellent effect as a thickener for a composition containing a high concentration of alcohol.

  The thickener used in the present invention is used for thickening or gelation, and when blended as a thickener in a scalp and hair composition, it exhibits an excellent thickening effect and prevents dripping from the application site. To do. Furthermore, it is possible to produce a composition for scalp and hair with a very good feeling of use because the stickiness when using a composition for scalp and hair, which has been regarded as a problem with conventional thickeners, and the stickiness when drying are drastically improved. become.

The composition for scalp and hair of the present invention is produced by blending the above microgel as a thickener into a composition base for scalp and hair. The blending amount of the thickener is appropriately determined according to the target scalp hair composition and is not limited. From the viewpoint of usability, the preferable blending amount is 0.01 to 10% (mass percentage), more preferably 0.1 to 5% (mass percentage).
When the content of alcohol in the composition is 20 to 90% by mass, particularly 60% by mass or more, a content of 0.01 to 10% by mass is preferable.
Moreover, it is preferable to mix | blend so that the viscosity of the composition in 30 degreeC may be 10-10000 mPa * s. The viscosity of this composition is the rotor No. of a B-type viscometer (VS-A type manufactured by Shibaura System). 2, measured at 12 rpm.

  The hair restoring agent used in the present invention is not particularly limited. For example, a blood circulation promoter, 5α-reductase inhibitor, follicular hormone, local stimulant, antibacterial agent, antiseborrheic agent, anti-inflammatory agent, hair follicle activator and the like can be mentioned. Further, it may be various plant extracts formulated for hair growth.

Preferred blood circulation promoters for the present invention are cephalanthin, nicotinic acid, benzyl nicotinate, tocopherol nicotinate, nicotinic acid β-butoxy ester, minoxidil or analogs thereof, assembly extract, vitamin Es, γ-oryzanol, alkoxycarbonylpyridine Examples thereof include N-oxide, carpronium chloride, acetylcholine, and derivatives thereof.
Preferred 5α-reductase inhibitors for the present invention include β-glycyrrhetinic acid, oxendron, finasteride and the like.

Preferred follicular hormones for the present invention include estradiol and its esters, estrone, estriol, echrin, echilenin, homoestrone, ethinyl estradiol, dowadinoleic acid, diethylstilbestrol, hexestrol and the like.
Preferable local stimulants for the present invention include chili pepper tincture, ginger tincture, cantharis tincture, camphor and nonyl acid vanillylamide.

Preferred antibacterial agents for the present invention include benzalkonium chloride, isopropylmethylphenol, resorcin, zinc pyrithione, photosensitive element 101, photosensitive element 201, salicylic acid, sodium salicylate, octopirox, hinokitiol and the like.
Examples of the antiseborrheic agent used in the present invention include pyridoxines, sulfur, and hydroxyflutamide.

  Preferred anti-inflammatory agents for the present invention include allantoin, ictamol, guaiazulene, epsilon aminocaproic acid, lysozyme chloride, diphenhydramine hydrochloride, menthols and the like.

  Preferred hair follicle activators for the present invention are nicotinamide, vitamin B6 and its derivatives, biotin, pantothenic acid and its derivatives, mononitroguaiacol, mononitroguaiacol sodium, 6-benzylaminopurine, diisopropylamine dichloroacetic acid, pentadecane An acid monoglyceride etc. are mentioned.

  Also, plant extracts usually incorporated in hair nourishing agents, for example, Altea extract, Yotei extract, pepper extract, aloe extract, wolfberry extract, mugwort extract, rice extract, bay extract, mannen wax extract , Kossaiho extract, Enishida extract, Gentian extract, Tanjin extract, Loofah extract, Pepper extract, Pine extract, Kuchacharate extract, Tokyo extract, Peonies extract, Safflower extract, Barberry extract, Areca extract Extract, Eucalyptus extract, Kagoso extract, Mokutsu extract, Goshitsu extract, Psycho extract, Tea extract, Licorice extract, Hop extract, Chrysanthemum extract, Senegal extract, Sesame extract, Senkyu extract , Kashuu extract, Cuckoo extract, Button extract, Mikaika extract, Saffron extract, Rosemary Extract, rehmannia root extract, mallow extract, moutan bark extract, peppermint extract, Coix extract or the like can also be incorporated into the compositions for the present invention scalp hair.

  The blending amount of the hair-restoring agent is appropriately determined and not limited depending on the intended scalp and hair composition. Usually, the blending amount is 0.0001 to 10% (mass percentage), preferably 0.001 to 5% (mass percentage).

  The composition for scalp and hair of the present invention includes a refreshing agent such as menthol, a salicylic acid, zinc or a derivative thereof, a drug such as lactic acid or an alkyl ester thereof, an organic acid such as citric acid, a protease inhibitor such as tranexamic acid, an arginine and the like Amino acids such as olive oil, squalane, liquid paraffin, isopropyl myristate, higher fatty acids, higher alcohols, polyhydric alcohols such as glycerin and propylene glycol, surfactants, moisturizers, thickeners used in the present invention Thickeners, fragrances, antioxidants, ultraviolet absorbers, pigments, water, and the like can be appropriately blended in the composition as long as the intended effects of the present invention are not impaired.

The kind and the adjustment method of the composition for scalp and hair of the present invention are not particularly limited. Manufactured by mixing compounding ingredients by conventional methods. Moreover, it is also possible to adjust the composition for emulsified scalp and hair by mixing and stirring with an oily base.
The scalp scalp hair composition of the present invention exhibits a stable thickening effect, and there is no problem in appearance caused by a thickener made of a conventional polymer gel.
The composition for scalp and hair of the present invention is preferably used as a cosmetic for scalp and hair such as a hair restorer, hair nick, hair liquid and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The blending amounts in the examples are mass% (mass percentage) unless otherwise specified.

  First, a synthesis example of a microgel used as a thickener in the present invention will be described. The microgel obtained in the synthesis example is the thickener of the present invention. The polymers of Comparative Examples 1 and 2 produced under polymerization conditions that do not form a fine W / O emulsion are not thickeners according to the present invention (does not meet the requirements set forth in the claims).

Synthesis example 1
40 g of dimethylacrylamide (manufactured by Kojin) and 9 g of 2-acrylamido-2-methylpropanesulfonic acid (manufactured by Sigma) are dissolved in 250 g of ion-exchanged water and adjusted to pH = 7.0 with sodium hydroxide. To a 1000 ml three-necked flask equipped with a reflux apparatus, 250 g of n-hexane, 8.2 g of polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) and polyoxyethylene (6) oleyl ether (Emalex 506, 16.4g (made in Japan Emulsion) is mixed and dissolved to replace N ₂ . An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis example 2
35 g of dimethylacrylamide (manufactured by Kojin) and 17.5 g of 2-acrylamido-2-methylpropanesulfonic acid (manufactured by Sigma) are dissolved in 260 g of ion-exchanged water and adjusted to pH = 7.0 with sodium hydroxide. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane, polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) 8.7 g and polyoxyethylene (6) oleyl ether (Emalex 506, Japanese-made emulsion) 17.6g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis example 3
30 g of dimethylacrylamide (manufactured by Kojin) and 26.7 g of 2-acrylamido-2-methylpropanesulfonic acid (manufactured by Sigma) are dissolved in 280 g of ion-exchanged water and adjusted to pH = 7.0 with sodium hydroxide. To a 1000 ml three-necked flask equipped with a reflux apparatus, 280 g of n-hexane, 9.4 g of polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) and polyoxyethylene (6) oleyl ether (Emalex 506, Japanese-made emulsion) 19g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis example 4
Dissolve 35 g of dimethylacrylamide (manufactured by Kojin), 17.5 g of 2-acrylamide-2-methylpropanesulfonic acid (manufactured by Sigma) and 7 mg of methylenebisacrylamide in 260 g of ion-exchanged water, and adjust the pH to 7.0 with sodium hydroxide. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane, polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) 8.7 g and epolyoxyethylene (6) oleyl ether (Emalex 506) , manufactured by Nippon emulsion) 17.6g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis example 5
Dissolve 35 g of dimethylacrylamide (manufactured by Kojin), 17.5 g of 2-acrylamide-2-methylpropanesulfonic acid (manufactured by Sigma) and 70 mg of methylenebisacrylamide in 260 g of ion-exchanged water, and adjust the pH to 7.0 with sodium hydroxide. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane, polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) 8.7 g and polyoxyethylene (6) oleyl ether (Emalex 506, Japanese-made emulsion) 17.6g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis Example 6
Dissolve 35 g of dimethylacrylamide (manufactured by Kojin) and 17.5 g of N, N-dimethylaminopropylacrylamide methyl chloride (manufactured by Kojin) in 260 g of ion-exchanged water. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane, polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) 8.7 g and polyoxyethylene (6) oleyl ether (Emalex 506, Japanese-made emulsion) 17.6g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Synthesis example 7
Dissolve 35 g of dimethylacrylamide (manufactured by Kojin), 17.5 g of N, N-dimethylaminopropylacrylamide methyl chloride (manufactured by Kojin) and 7 mg of methylenebisacrylamide in 260 g of ion-exchanged water. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane, polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nippon Emulsion) 8.7 g and polyoxyethylene (6) oleyl ether (Emalex 506, Japanese-made emulsion) 17.6g were mixed and dissolved into the N ₂ to replace. An aqueous monomer solution is added to the three-necked flask and heated to 65 ° C. to 70 ° C. in an oil bath while stirring under an N ₂ atmosphere. After confirming that the system is in a translucent microemulsion state when the temperature of the system reaches 65 ° C. to 70 ° C., 2 g of ammonium persulfate is added to the polymerization system and polymerization is started. A microgel is formed by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After the polymerization is completed, acetone is added to the microgel suspension to precipitate the microgel, followed by washing with acetone three times to remove residual monomer and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a dried white powdered microgel.

Comparative Synthesis Example 1
30 g of acrylamide (manufactured by Wako Pure Chemical Industries) and 21.6 g of methacryloxyethyl sulfonic acid (manufactured by Nippon Emulsifier) are dissolved in 260 g of ion-exchanged water. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane and 26 g of polyoxyethylene (3) oleyl ether (Emalex 503, manufactured by Nihon Emulsion Co., Ltd.) are mixed, dissolved, and N ₂ substituted. A monomer aqueous solution is added to this three-necked flask and heated to 65-70 ° C. in an oil bath while stirring in an N ₂ atmosphere. When the desired temperature is reached, 2 g of ammonium persulfate is added to the polymerization system to initiate polymerization. To do. A polymer is produced by maintaining the polymerization system at 65-70 ° C. with stirring for 3 hours. After completion of the polymerization, acetone is added to the polymer suspension to precipitate the polymer, followed by washing with acetone three times to remove residual monomers and surfactant. The precipitate is filtered and dried under reduced pressure to obtain a bulk polymer dried product. This is mechanically pulverized by a bead mill to obtain a white powder.

Comparative Synthesis Example 2
30 g of acrylamide (manufactured by Wako Pure Chemical Industries) and 21.6 g of methacryloxyethyl sulfonic acid (manufactured by Nippon Emulsifier) are dissolved in 260 g of ion-exchanged water. In a 1000 ml three-necked flask equipped with a reflux apparatus, 260 g of n-hexane and 26 g of polyoxyethylene (6) oleyl ether (Emalex 506, manufactured by Nihon Emulsion Co., Ltd.) are mixed, dissolved, and N ₂ substituted. A monomer aqueous solution is added to this three-necked flask and heated to 65-70 ° C. in an oil bath while stirring in an N ₂ atmosphere. When the desired temperature is reached, 2 g of ammonium persulfate is added to the polymerization system to initiate polymerization. To do. By maintaining the polymerization system at 65 to 70 ° C. with stirring for 3 hours, an aggregate (gel) is formed. After completion of the polymerization, the aggregate (gel) is washed with acetone three times to remove residual monomers and surfactant. The gel is dried under reduced pressure after filtration to obtain a bulk gel dried product. This is mechanically pulverized by a bead mill to obtain a white powder.

Viscosity behavior of scalp and hair composition As one index showing the thickening effect of the microgels obtained in the synthesis examples and comparative synthesis examples, the viscosity behavior of the composition for scalp and hair described below was examined. An aqueous dispersion was prepared by dispersing 0.3% by mass of the microgels of Synthesis Examples 1 to 7, the polymers of Comparative Synthesis Examples 1 and 2 as comparative examples, and hydroxypropyl methylcellulose. The viscosity is the rotor No. of a B type viscometer (VS-A type, manufactured by Shibaura System). The measurement was performed at 2, 12 rpm. The results are shown in Table 1.

Formulations of Examples 1 to 7 and Comparative Examples 1 to 3 (Compounding components) Compounding amount (% by mass)
(1) Ethyl alcohol 80.0
(2) Nicotinic acid benzyl ester 0.1
(3) β-glycyrrhetinic acid 0.3
(4) Ethinyl estradiol 0.001
(5) Pepper tincture 0.5
(6) Hinokitiol 0.05
(7) Nicotinamide 0.2
(8) 1,3-butylene glycol 2.0
(9) L-Menthol 1.0
(10) Ion-exchanged water residue (11) Succinic acid appropriate amount (12) Fragrance appropriate amount (13) Thickener of Table 1 0.3
Total 100

Production method: (2) to (9) were dissolved in (1), and (10) in which appropriate amounts of (11) and (12) were dissolved to add pH 4 was added and mixed. (13) was added and mixed and dissolved to obtain a composition for scalp and hair.

  Hydroxypropylcellulose can hardly thicken alcohol. Further, as shown in Comparative Examples 1 and 2, the polymer powders of Comparative Synthesis Examples 1 and 2 cannot be completely precipitated and swollen in alcohol. On the other hand, it was revealed that the microgel used in the present invention can sufficiently thicken or gel alcohol. It has been clarified that the thickening effect of alcohol is exhibited regardless of whether the microgel is copolymerized with a crosslinkable monomer.

Dynamic Elastic Modulus of Microgel Dispersion A characteristic of gel is that its mechanical properties behave “solidly” even though most of its constituents are liquid. On the other hand, even if such a gel is finely pulverized, the mechanical properties viewed macroscopically are maintained. For example, the present inventors compared the mechanical properties of both a bulk gel and a crushed gel for agar gel, and reported that the pulverized microgel qualitatively exhibits the same properties as the bulk gel. (Kaneda, Yanagi Journal of Japanese Society of Rheology vol.30 No.2, 89-94 2002).

That is, it is possible to confirm that the fluid has a microgel shape by measuring the dynamic elastic modulus. In order to clarify such physical properties of the present invention, the dynamic elastic modulus of water and alcohol dispersions was measured. The dynamic elastic modulus was measured at 25 ° C. in a strain 1% frequency range of 0.03 to 3 Hz using a cone-plate rheometer (Paar Physica MCR-300). The microgel obtained in Synthesis Example 2 was dispersed in water, ethanol, and a water-ethanol mixed solution (water: ethanol = 20: 80) at 0.5% (mass percentage), and the result of each dynamic elastic modulus. Are shown in FIG. 3 (water), FIG. 4 (ethanol) and FIG. 5 (water-ethanol mixed solution).
The vertical axis of the graph is the storage elastic modulus G ′ (Pa) and the loss elastic modulus G ″ (Pa), and the horizontal axis is the angular frequency. The value of G ′ is the “solid state property” of the test substance. Shows “liquid properties”. That is, it can be determined semi-quantitatively from this graph that “solid (gel)” if G ′> G ″ and “liquid (sol)” if G ′ <G ”.

It can be seen that both results show a typical gel-like property of G ′ (storage elastic modulus)> G ″ (loss elastic modulus) in the measurement frequency range. It can be seen that the thickening effect is due to the friction of fine microgels that exhibit gel-like or solid properties.
Note that such a gel-like dynamic elastic modulus behavior was not observed in the sample having a low apparent viscosity value at 1 s ⁻¹ .

Function as acid-resistant thickener A microgel containing sulfonic acid as a copolymerization monomer can be expected to show a stable thickening effect in a wide pH range. As a synthesis example 2 and a comparative example, the viscosity behavior in each pH region of a 0.5% (mass percentage) aqueous dispersion of sinterene L was examined. In the measurement, the apparent viscosity at a shear rate of 1 s ⁻¹ was measured at 25 ° C. by the same method as in (1) above. The results are shown in FIG. The microgel of Synthesis Example 2 showed a stable thickening effect in the range of pH = 2 to 11.

Effect and feeling of use of the composition for scalp and hair of the present invention The feeling and the effect of use of the microgel in the present invention when blended in a hair-care product were examined. A composition for scalp having the blending components shown in Table 2 (Example 8, Comparative Examples 4 to 8) was prepared according to a conventional method, and each test was performed.

Hair nourishing effect test In order to examine the hair nourishing effect of the composition for scalp scalp hair of the present invention, a tricogram test was conducted. The test subjects were male, and the comparative examples were 5 in each group and 4 in each example group. The test application period was 4 months, and 2-4 ml of this sample was applied to the scalp twice a day. Immediately before application and 4 months after application, each subject randomly removes 100 hairs from the top of the head, observes the hair root of the removed hair under a microscope, and calculates the hair root resting rate (%) from the state of the hair root. did. The rate of increase / decrease in the resting period before and after the sample application was determined according to the following criteria.

<Criteria>
4: Hair root resting rate decreased by 30% or more 3: Hair root resting rate decreased by 10% or more and less than 30% 2: Hair root resting rate decreased by less than 10% 1: Hair root resting rate increased Evaluation ◎: Average point is 3.5 or more ○: Average point is 3 or more and less than 3.5 Δ: Average point is 2 or more and less than 3 ×: Average point is less than 2

Hair removal prevention test The hair removal prevention effect was determined by the change in the number of hair removals before and after using the sample. The test subjects were male, and the comparative example was 8 people in each group and 4 people in each example group. The test period was 6 months, the first 2 months were the period during which the sample was not applied, and the latter 4 months were the period during which the sample was applied. During the sample application period, the sample was applied to the scalp twice a day, 2-4 ml of sample at a time. During the test period, the hair was washed every other day to collect the hairs, and the number of hairs was counted for one week.
For each period, the number of hairs to be removed is displayed for the period of 2 months when the sample is not applied, a total of 8 data for the number of hairs to be removed, and for the last 2 months of the sample application period, the data for the total number of hairs for 8 times. The number of hairs removed per time was displayed in the form of an average value and standard deviation. The effect was determined from the difference between the average values of the respective periods as follows.

<Criteria>
4: The number of extracted hairs decreased by 70 or more, and a remarkable effect was observed 3: The number of extracted hairs decreased by 40 or more, and a considerable effect was observed 2: The number of extracted hairs decreased by 10 or more, and the effect was somewhat Recognized 1: Less than 10 reductions in hair removal and invalid evaluation ◎: Average score of 3.5 or more ○: Average score of 3 or more and less than 3.5 Δ: Average score of 2 or more and less than 3 X: Average score is less than 2

Anti-dandruff test against dandruff The anti-dandruff effect was compared by the amount of protein in the dandruff before and after the sample was used and the degree of itch. There were 4 subjects in each group in the examples and comparative examples. The sample application period was 3 months, during which time the hair was washed once a day with the same shampoo to which no drug was added, and 2 to 4 ml of the test sample was applied to the scalp twice a day.
Immediately before application and at the end of application for 3 months, dandruff of the head was collected from the subject with a suction device before washing the hair, and the amount of protein in the dandruff was measured. The anti-dandruff effect of each sample was compared by increasing / decreasing the average amount of dandruff before and after sample application. In addition, after completion of the test, itching of each subject's scalp was investigated, and the degree of itching was represented by the following score.

Anti-dandruff score 4: remarkable effect 3: weak effect 2: no effect 1: worse itch score 4: no itching 3: some itching 2: some itching
1: Evaluation with strong itching ◎: Average score of 3.5 or more ○: Average score of 3 or more and less than 3.5 Δ: Average score of 2 or more and less than 3 ×: Average score of less than 2

Usability The ease of application during application, the degree of dripping, stickiness, and refreshing feeling were evaluated.
<Criteria>
4: Very good 3: Excellent 2: Neither 1: Inferior evaluation ◎: Average score of 3.5 or more ○: Average score of 3 or more and less than 3.5 Δ: Average score of 2 or more 3 Less than x: Average score is less than 2

In addition, in the composition for scalp and hair obtained in the comparative example 5, since precipitation was produced, the test was not implemented.

From these results, the microgel used in the present invention was blended into the scalp and hair composition and thickened, so that the hair drop is obviously less than the comparative example 4 which is a composition for scalp and hair without blending the microgel. It has been found that the effect, the effect of preventing hair loss, and the effect of preventing dandruff are strengthened. Furthermore, it was confirmed that the refreshing feeling was improved. From the results of Comparative Examples 5, 6 and 7, other thickeners could not confirm the excellent effect as in the present invention. In Comparative Examples 6 and 7, the intended thickening effect cannot be obtained and falls off. In Comparative Example 8, it was confirmed that although the viscosity was slightly increased, the effect and usability were clearly impaired.
That is, in a composition having an organic solvent or oil as a dispersion medium and water as a dispersion phase, a thickener comprising a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer in the dispersion phase and radical polymerization in the dispersion phase. By combining ethyl alcohol with one or more of blood circulation promoter, 5α-reductase inhibitor, follicular hormone, local stimulant, antibacterial agent, antiseborrheic agent, anti-inflammatory agent and hair follicle activator The obtained composition for scalp and scalp hair was found to have remarkable synergistic hair nourishing effects, hair loss preventing effects and dandruff and itching preventing effects. Further, in terms of usability, it is shown that the extremely high effect is due to the occlusion effect and the fact that it does not fall off.

  The following are other prescription examples of the cosmetics for hair of the present invention.

Example 9 Lotion (blending component) Blending amount (mass%)
(1) Ethyl alcohol 65.0
(2) Tocopherol nicotinate 0.2
(3) Isopropylmethylphenol 0.3
(4) Propylene glycol 2.0
(5) Eucalyptus oil 0.1
(6) Ion-exchanged water residue (7) Malic acid appropriate amount (8) Microgel of Synthesis Example 4 0.5
Total 100

Production method: (2) to (5) were dissolved in (1), and (6) in which (7) was dissolved was added and mixed. (8) was added and mixed and dissolved to obtain a composition for scalp and hair. When the above test was conducted on the scalp scalp hair composition of the present invention, a hair nourishing effect, a hair loss preventing effect, and a dandruff and scab preventing effect were remarkably recognized. It was also recognized as having excellent usability and not sagging or sticky.

Example 10 Lotion (Compounding ingredients) Blending quantity (mass%)
(1) Ethyl alcohol 60.0
(2) Minoxidil 3.0
(3) β-glycyrrhetinic acid 0.1
(4) Dipropylene glycol 20.0
(5) Eucalyptus oil 0.1
(6) Ion exchange water residue (7) Microgel of Synthesis Example 6 0.5
Total 100

Production method: (3) and (5) were dissolved in (1), and (4) dissolved (2) was added and mixed. After adding (6) and mixing, (7) was mixed and dissolved to obtain a composition for scalp and hair. When the above test was conducted on the scalp scalp hair composition of the present invention, a hair nourishing effect, a hair loss preventing effect, and a dandruff and scab preventing effect were remarkably recognized. It was also recognized as having excellent usability and not sagging or sticky.

Example 11 Lotion (blending component) Blending amount (mass%)
(1) Ethyl alcohol 85.0
(2) Decyltetradecyldimethylamine oxide 3.0
(3) β-glycyrrhetinic acid 0.5
(4) 1,3-butylene glycol 2.0
(5) Hardened castor oil ethylene oxide (60 mol) adduct 1.0
(6) Sodium lauryl sulfate 0.5
(7) Lactic acid Appropriate amount (8) Sodium lactate Appropriate amount (9) Ion-exchanged water Residue (10) Fragrance Appropriate amount (11) Microgel of Synthesis Example 6 2.0
Total 100

Production method: (2) to (5) and (10) were dissolved in (1), and (6) dissolved (9) was added and mixed. After dissolving (7) and (8) in a part of (9) and adding and mixing, (11) was mixed and dissolved to obtain a composition for scalp and hair. When the above test was conducted on the scalp scalp hair composition of the present invention, a hair nourishing effect, a hair loss preventing effect, and a dandruff and scab preventing effect were remarkably recognized. It was also recognized as having excellent usability and not sagging or sticky.

Example 12 Emulsification Lotion (Compounding Component) Blending amount (mass%)
(1) Ethyl alcohol 60.0
(2) Nicotinic acid benzyl ester 0.05
(3) β-glycyrrhetinic acid 1.0
(4) Tocopherol acetate 0.5
(5) Quacharalate extract 0.3
(6) Salamander extract 8.0
(7) Coriander extract 0.2
(8) Hop extract 0.2
(9) Ginseng extract 0.2
(10) Sucrose 0.2
(11) Squalane 1.0
(12) Hardened castor oil ethylene oxide (40 mol) adduct 1.0
(13) Appropriate amount of succinic acid (14) ion-exchanged water residue (15) Microgel of Synthesis Example 4 0.8
Total 100

Production method: (2) to (4) were dissolved in (1), and (14) dissolved in (5) to (10) was added and mixed. (11) to (13) were added to a part of (14) and emulsified, and then added to the above mixture. Here, (15) was mixed and dissolved to obtain a composition for scalp and hair. When the above test was conducted on the scalp scalp hair composition of the present invention, a hair nourishing effect, a hair loss preventing effect, and a dandruff and scab preventing effect were remarkably recognized. It was also recognized as having excellent usability and not sagging or sticky.

Example 13 Aerosol hair restorer <stock solution>
(Blending ingredients) Blending amount (% by mass)
(1) Ethyl alcohol 70.0
(2) Nicotinic acid 0.2
(3) β-glycyrrhetinic acid 0.5
(4) Pantotenyl alcohol 0.5
(5) Pepper tincture 0.3
(6) Hop extract 1.0
(7) Coriander extract 0.1
(8) Peonies extract 1.0
(9) Cousin extract 0.1
(10) Isostearyl alcohol 1.0
(11) L-menthol 0.5
(12) Hardened castor oil ethylene oxide (60 mol) adduct 0.05
(13) Malic acid appropriate amount (14) ion-exchanged water residue (15) Microgel of Synthesis Example 4 1.0
Total 100

Production method: (2) to (4) and (10) to (12) were dissolved in (1), and (5) to (9) were added and mixed. (13) was added to (14) and dissolved, and then added to the above mixture. Here, (15) was mixed and dissolved to obtain a stock solution. The stock solution was pressurized with nitrogen to 0.8 MPa to obtain a composition for scalp and hair. When the above test was conducted on the scalp scalp hair composition of the present invention, a hair nourishing effect, a hair loss preventing effect, and a dandruff and scab preventing effect were remarkably recognized. It was also recognized as having excellent usability and not sagging or sticky.

Example 14 Transparent Gel Hair Conditioner (Compounding Component) Blending amount (mass%)
(1) Ethyl alcohol 65.0
(2) Berthamol DG-25 (manufactured by NOF Corporation) 8.0
(3) Berthamol P-700 (Nippon Yushi Co., Ltd.) 5.0
(4) Butylene glycol 5.0
(5) Hardened castor oil ethylene oxide (60 mol) adduct 0.5
(6) Fragrance Appropriate amount (7) Dye Appropriate amount (8) Ion-exchanged water Residue (9) Microgel of Synthesis Example 4 5.0
Total 100

Production method: (2) to (7) were dissolved in (1), (9) was added to (8) and dissolved to obtain a composition for scalp and hair. This scalp scalp hair composition of the present invention was refreshed and excellent in the feeling of use, and it was confirmed that it was not dripped or sticky.

  The present invention provides a composition for scalp and hair containing a novel thickener. In particular, a scalp and hair composition that exhibits an excellent thickening effect is also provided in a scalp and hair cosmetic that contains a high amount of ethanol.

FIG. 3 is a three-component phase diagram of hexane (indicated by W) / surfactant / water-soluble ethylene monomer aqueous solution (indicated by O). It is a graph showing the dynamic elastic modulus of water. It is a graph showing the dynamic elastic modulus of ethanol. It is a graph showing the dynamic elastic modulus of a water-ethanol mixed solution. It is a graph showing the relationship between a viscosity and pH.

Claims (7)

In a composition having an organic solvent or oil as a dispersion medium and water as a dispersed phase, by using a surfactant, the polymerization system in the inverse emulsion polymerization forms a one-phase microemulsion or a fine W / O emulsion. In the composition for scalp and hair containing a thickener comprising a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer in a dispersed phase and radical polymerization in the dispersed phase, and ethyl alcohol, Water-soluble ethylenically unsaturated monomer
A dialkylacrylamide represented by the following general formula (1):
Formulating an anionic acrylamide derivative represented by the following general formula (2) or a cationic acrylamide derivative represented by the following general formula (3) with a thickener powder:
A composition for scalp and hair, wherein the content of the ethyl alcohol is 20 to 90% by mass and the thickener comprising the microgel is 0.01 to 10% by mass with respect to the total amount of the composition.
General formula (1)

(R ₁ represents H or a methyl group, and R ₂ and R ₃ each independently represents a methyl group, an ethyl group, a propyl group, or an isopropyl group.)

General formula (2)

(R ₄ and R ₅ each independently represent H or a methyl group, R ₆ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a metal ion or NH _3. )

General formula (3)

(R ₇ is H or a methyl group, R ₈ is H or a linear or branched alkyl group having 1 to 6 carbon atoms, R ₉ is a linear or branched alkyl group having 1 to 6 carbon atoms, R ₁₀ , R ₁₁ and R ₁₂ represent a methyl group or an ethyl group, and Y represents a chloride ion.)
In a composition having an organic solvent or oil as a dispersion medium and water as a dispersed phase, by using a surfactant, the polymerization system in the inverse emulsion polymerization forms a one-phase microemulsion or a fine W / O emulsion. In the composition for scalp and hair containing a thickener comprising a microgel obtained by dissolving a water-soluble ethylenically unsaturated monomer in a dispersed phase and radical polymerization in the dispersed phase, and ethyl alcohol, Water-soluble ethylenically unsaturated monomer
A dialkylacrylamide represented by the following general formula (1):
An anionic acrylamide derivative represented by the following general formula (2) or a cationic acrylamide derivative represented by the following general formula (3);
Formulating a thickener powder that is a crosslinking monomer represented by the following general formula (4),
A composition for scalp and hair, wherein the content of the ethyl alcohol is 20 to 90% by mass and the thickener comprising the microgel is 0.01 to 10% by mass with respect to the total amount of the composition.
General formula (1)

(R ₁ represents H or a methyl group, and R ₂ and R ₃ each independently represents a methyl group, an ethyl group, a propyl group, or an isopropyl group.)

General formula (2)

(R ₄ and R ₅ each independently represent H or a methyl group, R ₆ represents a linear or branched alkyl group having 1 to 6 carbon atoms, and X represents a metal ion or NH _3. )

General formula (3)

(R ₇ is H or methyl, R ₈ is H or a linear or branched alkyl group having 1 to 6 carbon atoms, R ₉ is a linear or branched alkyl group having 1 to 6 carbon atoms, R _10, R ₁₁ and R ₁₂ represent a methyl group or an ethyl group, and Y represents a chloride ion.)

General formula (4)

  The composition for scalp and hair according to claim 1 or 2, wherein the content of the ethyl alcohol is 60% by mass or more based on the total amount of the composition.   Furthermore, the scalp hair composition in any one of Claims 1-3 containing the chemical | medical agent for hair growth.   Furthermore, it contains one or more selected from the group consisting of a blood circulation promoter, 5α-reductase inhibitor, follicular hormone, local stimulant, antibacterial agent, antiseborrheic agent, anti-inflammatory agent, and hair follicle activator. The composition for scalp and hair according to any one of claims 1 to 3.   The composition for scalp and hair according to any one of claims 1 to 4, wherein the composition has a viscosity of 10 to 10000 mPa · s at 30 ° C.   The composition for scalp and hair according to any one of claims 1 to 6, wherein the composition for scalp and hair is a scalp and hair cosmetic.

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