JPH09227329A - Perfume base and external perfume - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an external perfume and base for perfume capable of reconciling the both easiness of applying to living body (skin, etc.) (and stability, quickness) and/or easiness of removing from living body. SOLUTION: This base for the perfume and the external perfume contains at least water and a gel forming component. A polymer compound having the solution sol-gel transition point >=10 deg.C and <=37 deg.C is used as gel forming component, and as a whole manifests practical insolubility in water at the temperature higher than the sol-gel transition point, and manifests reversible water solubility at lower than the sol-gel transition point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cosmetic base and a cosmetic for external use, and more specifically, it is in a sol state having fluidity at a temperature immediately before being applied to a living body (skin, etc.) by coating or the like. The present invention relates to a cosmetic base and a cosmetic for external use, which rapidly changes into a gel state due to body temperature and the like when applied to.
In the present specification, “cosmetics” is used to include “aroma products” and “quasi-drugs” in addition to “cosmetics” defined by the Pharmaceutical Affairs Law (Takeo Tamura and Hirota Hirota. Cosmetic Science ", p. 6, 1990, Fragrance Journal). The "base material" is a mixture or dispersion of "other ingredients" that compose a cosmetic product,
The medium (medium or matrix) used for the purpose of facilitating the application of the cosmetics to the living body (as well as the "other components" and t).
x).

The external cosmetic composition of the present invention can be suitably used, for example, as a cosmetic pack, a hair remover, or a decolorizing agent.

[0003]

2. Description of the Related Art Conventionally, in the field of cosmetics for external use, the easiness (and stability, quickness) of applying the cosmetics to the living body (skin, etc.) and / or the cosmetic for external use from the living body It has been extremely difficult to balance or balance the ease of removing the.

For example, in a cosmetic pack (pack for cosmetic use), which is one aspect of external cosmetics, inorganic powder is mixed with water, applied to the skin, and dried to form a film of the inorganic powder. A water-washable pack that is washed off with water or the like; a water-soluble polymer (polyvinyl alcohol, etc.) for film formation is dissolved in water, applied to the skin, and dried to form a thin film of the water-soluble polymer, It is roughly classified into a peelable pack for peeling the coating film.

Since the main component of any of the above-mentioned packs is water, it is necessary to evaporate and remove the water in order to form a film on the skin. Therefore, it takes a long time from application of the pack to film formation. Was needed. When the pack was used in the summer, it took a long time to form a film due to sweating or high humidity. Since the time it takes for the pack to dry is valuable for busy modern people, it is an important requirement for cosmetic packs that the coating be applied as quickly as possible.

Conventionally, a low-boiling substance such as ethyl alcohol is added to shorten the time until the formation of a film,
Alternatively, a method has been performed in which a solid content is increased by adding a filler such as an inorganic powder, a water-soluble polymer or a moisturizer.
However, the addition of large amounts of low-boiling substances such as ethyl alcohol to the pack unavoidably tends to over-irritate the skin. Further, an increase in the solid content in the pack reduces the fluidity of the pack, and the extension of the pack during application,
Not only does this reduce the storage stability of the pack itself, but it also results in a significant reduction in the water content, which is the maximum benefit of the cosmetic pack, to impart flexibility and tension to the skin.

Particularly, in the case of the conventional peelable pack, when the pack needs to be removed from the skin for some reason before the film is completely formed, the strength of the film containing water is weak, It has been pointed out that it is difficult to physically peel off the pack film, and the polymer partially forming the film becomes difficult to dissolve in water, so that it cannot be easily removed even by washing with water. .

On the other hand, in the depilatory agent which is another aspect of the cosmetic for external use, a depilatory agent (chemical depilatory agent) has been generally used for the purpose of removing hair under the axilla and body hair of limbs. Has been used.

Conventionally, the above chemical depilatory agent is a reducing agent (thioglycolic acid) which is a main component having an ability to solubilize by reducing cystine bond (disulfide bond) of keratin protein which is a main component of hair. Calcium, etc.) and pH to adjust the pH to 11 or higher to swell hair
It consists of a regulator (calcium hydroxide, etc.). Reducing agent (calcium thioglycolate, etc.) which is the main component of hair remover
Is very easily oxidized on the surface of the depilatory that is in contact with air, and the depilatory effect disappears, so that the depilatory is usually applied thickly on the skin. It has a paste-like or cream-like form.

Unlike the shaving, the depilatory is an important factor that the growth of the hair is slow and the skin after the depilation is smooth in order to remove the hair from the pores. Since the form of is paste or cream,
It has been pointed out that the hair remover is less likely to enter even fine pores.

Further, since the depilatory contains a drug having a strong reducing action, it has a strong irritation to the skin, and it is necessary to completely remove it from the skin as quickly as possible after depilation. However, since the conventional depilatory is in the form of paste or cream with high viscosity, it is not only very troublesome to remove it, but it is also necessary to completely remove the depilatory, especially the depilatory clogged in the pores. It was necessary to rub and wash the skin strongly to remove the agent. Further, in the case of such a paste-like or cream-like dehairing agent, due to the characteristics of its form, it may be placed in an incorrect location (for example, a location on the surface of the living body where hair removal is not desired) or a location other than the living body (such as clothing). In the case of adhesion, its removal was very troublesome.

[0012]

The object of the present invention is to provide a cosmetic composition for external use which eliminates the above-mentioned drawbacks of conventional cosmetic products for external use, and a cosmetic base which should give the cosmetic product together with "other components". To do.

Another object of the present invention is easiness (and stability, rapidity) when applied to a living body (skin, etc.), and / or
Another object of the present invention is to provide a cosmetic for external use and a cosmetic base which have both ease of removal from the living body.

Still another object of the present invention is to solve the above-mentioned problem that it takes a long time to form a film of a conventional cosmetic pack, by adding a large amount of a substance having a low boiling point such as ethyl alcohol or a solid content. It is to provide a cosmetic pack that eliminates the need to increase the amount.

Still another object of the present invention is to provide a cosmetic pack containing a sufficient amount of water for imparting sufficient flexibility, tension and moisturizing to the skin.

Still another object of the present invention is to eliminate the disadvantage of the conventional peelable pack which is difficult to peel and wash when the pack needs to be removed before the coating is completely formed. The purpose is to provide cosmetic packs.

Still another object of the present invention is that, as compared with the conventional hair remover, it can easily adhere even to the surface of skin having a complicated shape with unevenness at the time of application and penetrate into the pores. It is to provide a depilatory having a high depilatory effect.

Still another object of the present invention is to provide a hair remover which is significantly easier to remove than conventional hair removers and which can be completely removed from the pores.

Still another object of the present invention is that, as compared with the conventional decolorizing agent, it can easily adhere even to the surface of skin having a complicated shape with unevenness at the time of application and can penetrate into pores. , To provide a decolorizing agent having a high decolorizing effect.

Still another object of the present invention is to provide a decolorizing agent which is remarkably easy to remove as compared with conventional decolorizing agents and which can be completely removed from the pores.

[0021]

Means for Solving the Problems As a result of intensive studies by the present inventors, a polymer compound having characteristics completely different from the components contained in conventional cosmetics for external use; that is, its aqueous solution has a specific sol- A sol having a gel transition temperature and being substantially water-insoluble at a temperature higher than the sol-gel transition temperature,
-Use of a polymer compound reversibly soluble in water at a temperature lower than the gel transition temperature as a gel-forming component (gelling component) to form a cosmetic base or a cosmetic product has the above-mentioned problems. It was found to be extremely effective in solving the problem.

The cosmetic base of the present invention is based on the above findings, and more specifically, it is a cosmetic base containing at least water and a gel-forming component; A polymer compound having a sol-gel transition temperature higher than 37 ° C. and lower than 37 ° C .; and, as a whole base material, is substantially water-insoluble at a temperature higher than the sol-gel transition temperature, It is characterized by being reversibly water-soluble at a lower temperature.

According to the present invention, there is further provided a cosmetic product containing at least water and a gel-forming component; the gel-forming component having an aqueous solution whose sol-gel transition temperature is higher than 0 ° C and lower than 37 ° C. A high molecular weight compound having; and that the cosmetic as a whole exhibits substantially water insolubility at a temperature higher than the sol-gel transition temperature and reversibly exhibits water solubility at a temperature lower than the sol-gel transition temperature. A featured cosmetic for external use is provided.

The external cosmetic preparation (or base) of the present invention contains, as a gel-forming component, a polymer compound whose aqueous solution has a sol-gel transition temperature higher than 0 ° C. and lower than 37 ° C .; Immediately before applying the cosmetic to the living body (skin etc.), it is substantially water-insoluble at a temperature higher than the sol-gel transition temperature and reversibly water-soluble at a temperature lower than the sol-gel transition temperature. , (For example, by setting the temperature of cosmetics to be lower than the sol-gel transition temperature) in a highly fluid sol state (liquid state; water-soluble state), which can be easily applied to a living body by application or the like. it can. After application to a living body, the temperature of the cosmetic itself rises due to body temperature, etc., so that the cosmetic immediately gels (becomes substantially insoluble in water), so a stable film is quickly formed on the living body. Can be formed.

On the other hand, when removing the external cosmetic composition from the living body, for example, by returning the cosmetic composition to a sol state by lowering the temperature of the cosmetic composition, it becomes possible to remove the cosmetic composition from the living body extremely easily and completely. . In other words, both the ease of application to the living body (and stability and rapidity) and the ease of removing the external use cosmetic from the living body, which were extremely difficult with conventional external use cosmetics, are compatible. It will be possible.

When the above-mentioned cosmetic for external use of the present invention is used as a "cosmetic pack", the pack is in a sol (liquid) state at a temperature lower than the sol-gel transition temperature (for example, room temperature). Not only can it be simply applied to the surface of a living body having complicated irregularities such as the surface of the skin, but the pack can be made to enter even irregularities such as wrinkles. On the other hand, the cosmetic pack of the present invention rapidly changes into a gel state at a temperature higher than the sol-gel transition temperature, that is, the temperature of the surface of the skin, so that the retention property on the skin is remarkably improved.

As described above, the conventional cosmetic pack has a problem that it takes a long time to form a film because it forms a film by evaporating water after being applied to the skin. The cosmetic pack of the present invention is characterized in that when applied to the skin, it rapidly gels and forms a film, so that the time until the film formation is significantly shortened. Further, in the case of the conventional peelable pack, it is difficult to physically peel the coating during the formation of the coating, that is, in the state of being dry, the coating is weak, but the cosmetic pack of the present invention is Since the gel-like film is formed immediately when applied to the skin, it has a feature that it can be physically peeled off quickly (at any time) after application.

Further, the cosmetic pack of the present invention has a sol-gel transition temperature and changes to a sol state at a temperature lower than the sol-gel transition temperature. Therefore, the cosmetic pack is washed with cold water, for example. It can be easily removed. Further, since the cosmetic pack of the present invention forms a hydrogel containing a large amount of water on the skin, it can sufficiently impart flexibility, tension and moisturization to the skin. The cosmetics of the present invention
When the pack is applied to the skin, it immediately changes into a gel state, gradually evaporates water, and finally forms a thin film of the polymer compound, which is a component of the present invention, like the conventional cosmetic pack. It can be peeled off.

Further, in the case of the cosmetic pack of the present invention, it is possible to add conventionally used skin protectants, antioxidants, storage stabilizers, detergents, etc., and immediately after application to the skin. For gelation, each of the above components can be uniformly dispersed in the gel.

On the other hand, when the cosmetic for external use of the present invention is used as a "hair removal agent", the hair removal agent is in a sol (liquid) state at a temperature lower than the sol-gel transition temperature, for example, room temperature, Since the viscosity is significantly lower than that of the conventional cream- or paste-type conventional depilatory agent, it adheres to the surface of the skin having a complicated shape having irregularities at the time of application and can easily penetrate into the pores. The hair remover of the present invention rapidly changes into a gel state at a temperature higher than the sol-gel transition temperature, that is, the temperature of the surface of the skin, and at the same time, the retention property in the state of being adhered on the skin is remarkably improved. (Unlike the surface of a depilatory agent in the form of paste or paste), the surface of the gel is less sticky, and adhesion to clothes and the like can be significantly reduced.

After the hair remover of the present invention has been applied to the skin and the hair has been removed, the applied film of the hair remover of the present invention has gelled, so that the gelled coating film can be easily and physically formed. It can be peeled off from the skin (especially it can be easily removed from the pores), and it is a troublesome task such as strongly wiping the skin or washing with water like a conventional cream or paste dehairing agent. Can be omitted.

On the other hand, when the cosmetic for external use of the present invention is used as a "decoloring agent", the decolorizing agent is in a sol (liquid) state at a temperature lower than the sol-gel transition temperature, for example, at room temperature, Since the viscosity is significantly lower than that of a conventional decolorizing agent in the form of cream or paste, it adheres to the surface of skin having a complicated shape having irregularities during application and can easily penetrate into pores. The decolorizing agent of the present invention rapidly changes into a gel state at a temperature higher than the sol-gel transition temperature, that is, the temperature of the surface of the skin, remarkably improves the retention property in the state of being adhered on the skin, and Alternatively, unlike the surface of a paste-like decolorizing agent), the surface of the gel is less sticky, and the adhesion to clothes can be significantly reduced.

After the decoloring agent of the present invention is applied to the skin to carry out decolorization, the coating film of the decolorizing agent of the present invention is gelated, so that the gelled coating film is easily physically peeled from the skin. It can be removed (especially easily removed from pores), and you can save the troublesome work of wiping off the skin strongly and washing with water like a conventional cream or paste decolorizer. it can.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In the following description, "%" and "part" that represent the quantitative ratio
Is on a weight basis (ie, wt% and parts by weight) unless otherwise noted.

(Sol-Gel Transition Temperature) The definition and measurement of the “sol-gel transition temperature” of the “polymer compound having a sol-gel transition temperature” used in the present invention are described in the literature (H. Yos.
hioka et al., Journal of Macromolecular Science, A31
(1), 113 (1994)). That is, the dynamic elastic modulus of the sample at the observation frequency of 1 Hz gradually changes from the low temperature side to the high temperature side (1 ° C / 1 minute)
The temperature at which the storage elastic modulus (G ′, elastic term) of the sample exceeds the loss elastic modulus (G ″, viscous term) is measured by the sol-
It is the gel transition temperature. Generally, the state of G ″> G ′ is defined as sol, and the state of G ″ <G ′ is defined as gel.
When measuring the sol-gel transition temperature, the following measurement conditions can be preferably used.

<Dynamic / Loss Elastic Modulus Measuring Conditions> Measuring instrument (trade name): stress control rheometer CS
L700, manufactured by Carri-Med, Inc. Sample solution (or dispersion) concentration (provided as "polymer compound having sol-gel transition temperature" concentration): 10
(Weight)% Amount of sample solution: about 0.8 g Shape / dimension of measuring cell: acrylic parallel disk (diameter 4.0 cm), gap 600 μm.

Applied stress: Within the linear region.

The above-mentioned "polymer compound having a sol-gel transition temperature" is an aqueous solution or dispersion of the sol-gel.
At a temperature higher than the gel transition temperature, it becomes a gel (hydrogel) having poor fluidity, while at a temperature lower than the temperature, it becomes a sol (or liquid).

The polymers used in the present invention have a sol-gel transition temperature above 0 ° C and below 37 ° C. The sol-gel transition temperature is 1 in terms of enabling efficient gelation at the temperature (about 37 ° C.) of the surface of the living body (skin, etc.).
It is preferably 5 ° C. or higher and 35 ° C. or lower (further, 20 ° C. or higher and 30 ° C. or lower).

The polymer compound having a suitable sol-gel transition temperature as described above is selected from among the various polymer compounds (having the above-mentioned general characteristics) that can be used as a gel-forming component for external cosmetics. It can be easily selected according to the screening method (sol-gel transition temperature measurement method).

(Polymer Compound Having Sol-Gel Transition Temperature) The polymer compound usable in the external cosmetics of the present invention is
The polymer compound is not particularly limited as long as it has a sol-gel transition temperature higher than 0 ° C. and lower than 37 ° C. However, from the viewpoint of easy rapid change to water insolubility, the polymer compound has an aqueous solution of 0 ° C. A polymer compound in which a temperature-sensitive polymer portion (block) having an LCST higher than 37 ° C. and lower than 37 ° C. and a hydrophilic polymer portion are bonded is preferable, and the “temperature-sensitive polymer having LCST” is preferable. It is further preferable that the “part” is a polymer compound having a plurality of molecules in one molecule.

As used in the present invention, "the aqueous solution is LCS
The “temperature-sensitive polymer having T” is a polymer compound having a negative temperature coefficient of solubility in water, and a hydrate (which depends on the hydrogen bond between the polymer compound formed at low temperature and a water molecule ( Oxonium hydroxide) decomposes at high temperature,
It is characterized in that polymer compounds aggregate and precipitate by dehydration.

In the present invention, LCST (Lower Critic)
al Solution Temperature) refers to the transition temperature of hydration and dehydration of a polymer compound (for example, Heskins (M. He
skins) et al. J. Macromol. Sci.-Chem., A2 (8), 1441
(1968)). The temperature-sensitive polymer portion is hydrophilic at a temperature lower than LCST and soluble in water, but becomes hydrophobic at a temperature higher than LCST, becomes insoluble in water and precipitates, and this change is reversible. In the present invention, from the viewpoint that the above-mentioned polymer compound gives a reversible change of soluble-insoluble rapidly responding to the temperature of the living body surface and "the temperature lower than this", L of the above temperature-sensitive polymer portion is used.
CST is higher than 0 ° C and lower than 37 ° C (further, 15-37
C).

As long as it has the above-mentioned LCST, it can be used as the above temperature-sensitive polymer in the present invention without any particular limitation. Examples of the polymer compound that can be preferably used in the present invention include poly N-substituted acrylamide derivatives, poly N-substituted methacrylamide derivatives, copolymers thereof; polypropylene oxide, and copolymers of propylene oxide and other alkylene oxides. Polymers: polyvinyl methyl ether, polyvinyl alcohol partial acetic acid, polyalkylene oxide and the like.

The temperature-sensitive polymer compounds suitable for the present invention are listed below in the order of increasing LCST.

Poly-N-acryloylpiperidine; poly-N-n-propylmethacrylamide; poly-N-isopropylacrylamide; poly-N, N-diethylacrylamide; poly-N-isopropylmethacrylamide; poly-N-cyclopropyl Acrylamide; poly-N-acryloylpyrrolidine; poly-N, N-ethylmethylacrylamide; poly-N-cyclopropylmethacrylamide; poly-N-ethylacrylamide; the above-mentioned polymer is a homopolymer It may be a copolymer of a monomer constituting the above polymer and another monomer. As the other monomer constituting such a copolymer, any of a hydrophilic monomer and a hydrophobic monomer can be used.

Examples of the hydrophilic monomer include N-vinylpyrrolidone, vinylpyridine, acrylamide, methacrylamide, N-methylacrylamide, hydridoxyethyl methacrylate, hydroxyethyl acrylate, hydroxymethyl methacrylate, hydroxymethyl acrylate, and acid. Group-containing acrylic acid, methacrylic acid and salts thereof, vinyl sulfonic acid, styrene sulfonic acid, etc., and basic group-containing N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N- Examples include dimethylaminopropyl acrylamide and salts thereof,
It is not limited to these.

On the other hand, as the hydrophobic monomer, acrylate derivatives and methacrylate derivatives such as ethyl acrylate, methyl methacrylate, butyl methacrylate and glycidyl methacrylate, N-substituted alkyl methacrylamide derivatives such as Nn-butyl methacrylamide, Vinyl chloride, acrylonitrile, styrene,
Examples thereof include, but are not limited to, vinyl acetate and the like.

Generally, it is possible to increase the LCST by copolymerizing a hydrophilic monomer with the above-described polymer compound, while decreasing the LCST by copolymerizing a hydrophobic monomer. It becomes possible. Therefore, the desired LCS can also be obtained by selecting these copolymerization components (hydrophilic monomer and / or hydrophobic monomer).
A polymer compound having T can be obtained.

On the other hand, in the present invention, examples of the hydrophilic polymer compound to be combined with the temperature-sensitive polymer compound include methyl cellulose, dextran, polyethylene oxide, polyvinyl alcohol, poly N-vinylpyrrolidone, polyvinyl pyridine, polyacrylamide and poly. Methacrylamide, poly N-methyl acrylamide, poly hydroxymethyl acrylate, polyacrylic acid, polymethacrylic acid, polyvinyl sulfonic acid, polystyrene sulfonic acid and salts thereof, poly N, N-dimethylaminoethyl methacrylate, poly N, N-diethylamino Examples thereof include ethyl methacrylate, poly N, N-dimethylaminopropyl acrylamide and salts thereof.

The aqueous solution of the "polymer compound having a sol-gel transition temperature" used in the present invention is LCS.
Polymer part having T (A) and hydrophilic polymer part (B)
The bonding mode of the copolymer obtained by bonding and is not particularly limited, but for example, a block copolymer of A and B, a graft copolymer in which a side chain B is bonded to the main chain A, or a main chain B A mode such as a graft copolymer in which the side chain A is bonded can be preferably used.

The block copolymer of the polymer part having LCST and the hydrophilic polymer part has, for example, a functional group (hydroxyl group, carboxyl group, amino group, or
Can be obtained by introducing a plurality of isocyanate groups or the like and bonding them by a chemical reaction.

Generally, as a method for synthesizing a graft copolymer, 1) a method utilizing a chain transfer reaction of a polymer,
There are known 2) a method in which a functional group capable of being split into free radicals is introduced into the trunk polymer, and polymerization is started from the functional group. 3) A method in which ionic polymerization is started from the trunk polymer. The graft copolymer to be used in the present invention can be obtained by these methods, but from the viewpoint of controlling the degree of polymerization of side chains, one polymerizable functional group is added to the polymer portion having LCST. Introduced and copolymerized with a monomer that gives a hydrophilic polymer moiety; or with a monomer that introduces one polymerizable functional group into the hydrophilic polymer moiety and gives a polymer moiety having an LCST. It is advantageous to obtain it by copolymerization.

The "sol-" used in the cosmetics for external use of the present invention
The molecular weight of the "polymer compound having a gel transition temperature" is not particularly limited, but from the viewpoint of dispersion stability when used in a dispersion system (emulsion, dispersion, etc.), a larger molecular weight is more advantageous. More specifically, in the present invention, as the “polymer compound having a sol-gel transition temperature”, those containing at least those having a molecular weight of 100,000 or more are preferably used. "Molecular weight 1
"A polymer having a molecular weight of more than 0,000" means an aqueous solution (concentration: about 1%) having a molecular weight cut off of 100,000 at a temperature lower than the sol-gel transition temperature (manufactured by Amicon, trade name:
H1P100-43) means a substance which is not substantially filtered when subjected to ultrafiltration. Here, "substantially not filtered" means that when the volume of the stock solution is concentrated by ultrafiltration to 1/3, the concentration of the polymer compound detected in the filtrate is the high level in the stock solution (before concentration). It is 1/10 or less of the concentration of the molecular compound. This “not substantially filtered” means that, for example, the concentration ratio of the polymer compound in the stock solution and the filtrate is U
It can be confirmed by V measurement or the like.

In the above ultrafiltration, the following experimental conditions can be suitably used.

<Confirmation measurement conditions of ultrafiltration> Stock amount of polymer aqueous solution: about 3000 ml Ultrafiltration membrane: manufactured by Amicon, trade name: H1P100-4
3 (hollow fiber type).

Temperature: Below the sol-gel transition temperature of the "polymer compound having a sol-gel transition temperature" aqueous solution. Ultrafiltration Pressurization: 1 kg / cm ² Circulation flow rate: 5 l / min The aqueous solution of the “polymer compound having a sol-gel transition temperature” used in the present invention is fluid at low temperature (temperature lower than sol-gel transition). It is in the form of an aqueous solution and has a high temperature (sol-
At a temperature higher than the gel transition), it exhibits a thermoreversible sol-gel transition in which it loses fluidity and assumes a hydrogel state. According to the findings of the present inventors, the mechanism of such a thermoreversible sol-gel transition is presumed as follows.

That is, at a temperature lower than the LCST of the temperature-sensitive polymer portion present in the molecule, both the temperature-sensitive polymer portion and the hydrophilic polymer portion are water-soluble.
The “polymer compound having a sol-gel transition temperature” can be completely dissolved in water. However, when the temperature of this aqueous solution is raised to a temperature higher than the LCST, the temperature-sensitive polymer portion becomes water-insoluble (hydrophobic), and the hydrophobic interaction causes association between different molecules.

On the other hand, since the hydrophilic polymer portion remains water-soluble even at a temperature higher than the LCST, the presence of such a hydrophilic polymer portion indicates that the aggregation between the “polymer portion having LCST” is macroscopic. Phase separation and contribute to stable hydrogel formation.

When the temperature of the hydrogel thus formed is cooled again to a temperature lower than the LCST of the temperature-sensitive polymer portion present in the molecule, the temperature-sensitive polymer portion becomes water-soluble. Crosslinking points due to hydrophobic association are released, and the hydrogel structure disappears. Therefore, the “polymer compound having a sol-gel transition temperature” used in the present invention
Once again, it is completely soluble in water. As described above, this sol-gel transition is based on the reversible hydrophilic-hydrophobic change in the LCST of the temperature-sensitive polymer part existing in the molecule, and therefore, the sol-gel transition is completely dependent on the temperature change. Has reversibility.

The composition of a temperature-sensitive polymer portion having an LCST and a hydrophilic polymer portion, the degree of hydrophobicity of both polymer portions,
By adjusting the hydrophilicity and / or the molecular weight thereof, the sol-gel transition temperature of the polymer compound, that is,
The sol-gel transition temperature of the cosmetic composition for external use of the present invention can be controlled so as to be higher than 0 ° C and lower than 37 ° C.
In addition, "other components" added to the aqueous solution of the polymer compound
(Eg urea, guanidine, thioglycolate, p
It is possible to control the sol-gel transition temperature to be higher than 0 ° C. and lower than 37 ° C. even when a H adjusting agent is included.

The concentration of the above-mentioned polymer compound in the polymer compound aqueous solution constituting the cosmetic for external use of the present invention is not particularly limited as long as it is within the concentration range in which the sol-gel transition occurs substantially. From the viewpoint of water content as a cosmetic for external use or suppression of irritation to a living body based on osmotic action, the external concentration is usually in the range of 0.5% to 50% (further, 2% to 20%). It is preferable.

(Viscosity) From the viewpoint of easiness (extension, etc.) when applied to a living body by coating or the like, the viscosity of the cosmetic for external use of the present invention is the same as that of the "polymer compound having a sol-gel transition temperature" aqueous solution. Below the sol-gel transition temperature (eg 20 ° C),
It is preferably 1000 centipoise or less, more preferably 500 centipoise or less (particularly 200 centipoise or less). In the present invention, the viscosity of external cosmetics is, for example,
It is possible to measure under the following measurement conditions.

<Viscosity measuring conditions> Measuring instrument: manufactured by Tokyo Keiki Co., Ltd., trade name: B type viscometer rotor: "No. 3 rotor" is used Shear rate: 38 s ^-1 (dispersion medium) In the present invention, The dispersion medium that constitutes the hydrogel together with the “polymer having a sol-gel transition temperature” described above is preferably water or an aqueous liquid medium.

The "aqueous dispersion medium" may be in the form of a solution or a dispersion (dispersion, emulsion, etc.). From the point of stimulating the surface of the living body,
The "other liquid medium" (the following alcohol etc.) that constitutes the aqueous medium together with water is preferably 10% or less (more preferably 5% or less). As the "other liquid medium" in such an embodiment, for example, monohydric or polyhydric alcohols such as monohydric alcohols such as ethanol, dihydric alcohols such as ethylene glycol, and trihydric alcohols such as glycerin are preferable. It can be used.

(Cosmetic base) The cosmetic base of the present invention contains at least water and a gel-forming component; the gel-forming component is a sol-gel transition in which the aqueous solution thereof is higher than 0 ° C and lower than 37 ° C. It is composed of a polymer compound having a temperature; and, as the whole base material, is substantially water-insoluble at a temperature higher than the sol-gel transition temperature and reversibly water-soluble at a temperature lower than the sol-gel transition temperature. .

The "other ingredients" constituting the cosmetics together with the cosmetic base are selected from the conventionally known cosmetic ingredients as long as they do not substantially inhibit the sol-gel transition due to the temperature change. One or more components can be used without particular limitation. Even in this case, based on the use of the base of the present invention, there is provided a cosmetic product in which the easiness of application to the living body (and stability and quickness) and the ease of removal from the living body are well balanced. It becomes possible to obtain. Examples of the above-mentioned "other ingredients" that can be used in such an embodiment include, for example, basic cosmetics, makeup cosmetics, cosmetics for hair, aromatic cosmetics, dental cosmetics (toothpaste etc.), special cosmetics (system Sweat / deodorant, sunscreen / Santan products,
The components that make up acne products) and the like. For these various components, it is possible to refer to, for example, pages 3 to 10 of the above-mentioned document (Takeo Tamura / Hiroshi Hirota "Cosmetics Science", 1990, Fragrance Journal).

(Cosmetic pack) When the cosmetic for external use of the present invention is in the form of "cosmetic pack", the cosmetic pack comprises water; and the aqueous solution thereof has a sol-gel transition of higher than 0 ° C and lower than 37 ° C. At least a gel-forming component made of a polymer compound having a temperature.

The amount ratio of solids constituting the cosmetic pack is not particularly limited as long as it has the above-mentioned preferable viscosity as a whole, but usually 5
It is preferably 0% or less (based on the total weight of all the components of the cosmetic pack), and more preferably 30% or less.

(Water-Soluble Polymer) For the purpose of improving the releasability of the coating film of the above-mentioned cosmetic pack, the conventional cosmetic pack is used as long as the sol-gel transition property of the pack is not substantially impaired. The water-soluble polymer compound (polyvinyl alcohol, etc.) used in
It can be added as "another component". The amount ratio of the water-soluble polymer is not particularly limited as long as it has the “suitable viscosity” as the whole pack described above, but is usually 20 parts or less, and more preferably 20 parts or less with respect to 100 parts by weight of water constituting the pack. It is preferably 10 parts or less.

(Hair Removal Agent) When the cosmetic for external use of the present invention is used as a “hair removal agent”, the hair removal agent is water; and the sol-gel transition temperature at which the aqueous solution is higher than 0 ° C. and lower than 37 ° C. And a polymer compound having When a hair remover having such a component is used, for example, it is possible to remove hair by physical peeling. From the viewpoint of efficiently removing hair under mild conditions, it is preferable that the hair removing agent further contains thioglycolate. The amount of the thioglycollate used is not particularly limited, but is usually 1 part or more, further 1 to 10 parts (particularly 3 to 7 parts) with respect to 100 parts of water constituting the depilatory.
It is preferably about 1 part.

The above hair remover may contain other components, if necessary. As such “other components”, it is possible to use those known as conventional additives for dehairing agents within the range where the sol-gel transition is not substantially impaired. The amount ratio of the "other components" is not particularly limited as long as it has the "suitable viscosity" as the above-mentioned hair remover, but is usually 15 parts or less relative to 100 parts of water constituting the hair remover, Further, it is preferably 10 parts or less.

Examples of the "other components" used for such a purpose include p known as an additive for conventional hair removers.
An H regulator (calcium hydroxide, caustic alkali, etc.); or an auxiliary agent (urea and / or guanidine, etc.) may be contained.

(Additive) As described above, the cosmetic of the present invention contains at least a polymer compound having a specific sol-gel transition temperature and water, but may further contain other "additives". You may have. As such an "additive", it is possible to use a conventionally known additive for cosmetics for external use, within a range in which the sol-gel transition is not substantially impaired. The amount ratio of the "additive" is not particularly limited as long as it has the "suitable viscosity" as the above-mentioned cosmetics as a whole. It is preferably not more than part.

Examples of the "additive" used for such a purpose include a skin protective agent, an antioxidant, a storage stabilizer, a detergent, and a fragrance which are known as conventional additives for cosmetics.

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is limited by the claims and is not limited by the examples.

[0077]

EXAMPLES Example 1 (Synthesis of polymer having sol-gel transition temperature) N-isopropylacrylamide (manufactured by Eastman Kodak Company)
After dissolving 10.2 g and 1.71 g of N-acryloxysuccinimide (manufactured by Kokusan Kagaku Co., Ltd.) in 400 ml of chloroform in the reaction vessel and replacing the inside of the reaction vessel with nitrogen, N, N'-azo was obtained. Bisisobutyronitrile 0.135
g was added and the mixture was polymerized at 60 ° C. for 6 hours. After the reaction was complete, the reaction product was concentrated under reduced pressure and then precipitated in diethyl ether. The obtained precipitate was separated by filtration and then vacuum dried at about 40 ° C. for about 24 hours to obtain 8.8 g.
Poly (N-isopropylacrylamide-co-N-
Acryloxysuccinimide) was obtained.

1.0 g of the poly (N-isopropylacrylamide-co-N-acryloxysuccinimide) obtained above and aminated polyethylene oxide having both ends aminated (molecular weight 6,000, manufactured by Kawaken Fine Chemicals Co., Ltd.)
0.5 g was dissolved in 100 ml of chloroform and reacted at room temperature overnight (about 10 hours). Next, 0.1 g of isopropylamine is added, and the mixture is placed at 25 ° C. overnight (about 10 hours).
I left it.

The reaction product obtained was concentrated under reduced pressure and then precipitated in diethyl ether. The obtained precipitate is separated by filtration, dried and then diluted with 1000 ml of distilled water, and 10 ° C. using a hollow fiber type ultrafiltration membrane (H1P100-43 manufactured by Amicon) having a cut-off molecular weight of 100,000.
Was concentrated to 300 ml. 700 m of distilled water in the concentrate
1 was added to dilute, and the above dilution operation was repeated. The above-mentioned dilution and ultrafiltration concentration operations were repeated 5 times to remove those having a molecular weight of 100,000 or less. What was not filtered by this ultrafiltration (remaining in the ultrafiltration membrane) was collected, freeze-dried, and vacuum dried at about 40 ° C. for about 10 hours to obtain 1.3 g of “polymer compound”. I ”(a polymer compound having a sol-gel transition temperature) was obtained.

“Polymer compound I” thus obtained
1 g was dissolved in 9 g of distilled water at room temperature. The sol-gel transition temperature of this aqueous solution was measured as the temperature at which the above-mentioned storage elastic modulus (G ', elastic term) exceeds the loss elastic modulus (G ", viscous term). 35 ° C
Met.

Example 2 9.61 g of N-isopropylacrylamide and N-
1.71 g of acryloxysuccinimide and 0.71 g of n-butyl methacrylate were dissolved in 400 ml of chloroform in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by N, N'-azobisisobutyronitrile. 0.13
5 g was added and polymerized at 60 ° C. for 6 hours. The obtained reaction product was concentrated under reduced pressure, and then precipitated in diethyl ether. The resulting precipitate was separated by filtration and then dried in vacuo at about 40 ° C. for about 24 hours to obtain 7.8 g of poly (N
-Isopropylacrylamide-co-N-acryloxysuccinimide-co-n-butyl methacrylate)
I got

1.0 g of poly (N-isopropylacrylamide-co-N-acryloxysuccinimide-co-n-butylmethacrylate) obtained above and aminated polyethylene oxide having both ends at a molecular weight of 6,000,
0.5 g of Kawaken Fine Chemical Co., Ltd.) was dissolved in 100 ml of chloroform and left overnight at room temperature (about 10 hours).
After the reaction, 0.1 g of isopropylamine was added, and the mixture was left at about 25 ° C. overnight (about 10 hours). The reaction product obtained was concentrated under reduced pressure and then precipitated in diethyl ether. The obtained precipitate is separated by filtration, vacuum dried at about 40 ° C. for about 24 hours, and then diluted with 1000 ml of distilled water to obtain a hollow fiber type ultrafiltration membrane (H1P100-43 manufactured by Amicon) having a molecular weight cut off of 100,000. It was concentrated to 300 ml at 10 ° C. 700 ml of distilled water in the concentrate
Was added for dilution, and the above-mentioned dilution operation was repeated. The above-mentioned dilution and ultrafiltration concentration operation are repeated 5 times to obtain a molecular weight of 1
Those less than 0,000 were removed. What was not filtered by this ultrafiltration (remaining in the ultrafiltration membrane) was collected and lyophilized to give 1.3 g of "polymer compound II".
(A polymer compound having a sol-gel transition temperature) was obtained.

1 g of "polymer compound II" obtained above
Was dissolved in 9 g of distilled water under ice cooling. When the sol-gel transition temperature of this aqueous solution was measured by the same method as in Example 1, the sol-gel transition temperature was 21 ° C.

Example 3 Polyethylene oxide with aminated polyethylene at both ends (molecular weight: 6,000)
0, Kawaken Fine Chemical Co., Ltd. (3 g) was dissolved in 100 ml of chloroform, and then tolylene diisocyanate (Coronate T65, manufactured by Nippon Polyurethane Industry Co., Ltd.)
0.1 g of triaminopolypropylene oxide having a primary amino group at a terminal (average molecular weight: about 3,000, manufactured by Jefferson Chemical Company, USA: Jeffamine T-30)
00), and reacted at room temperature for 5 minutes. Then
Isopropylamine (1 g) was added, and the mixture was reacted overnight at room temperature (about 10 hours). The solvent was distilled off under reduced pressure to obtain "polymer compound" III (polymer compound having a sol-gel transition temperature).

1 g of "polymer compound III" obtained above
Was dissolved in 9 g of distilled water under ice cooling. When the sol-gel transition temperature of this aqueous solution was measured in the same manner as in Example 1, the sol-gel transition temperature was 15 ° C.

Example 4 Polyethylene oxide with aminated ends (molecular weight 6,0
00, manufactured by Kawaken Fine Chemicals Co., Ltd., 30 g was dissolved in 1000 ml of chloroform, and then tolylene diisocyanate (Coronate T65, Nippon Polyurethane Industry Co., Ltd.)
1) and triaminopolypropylene oxide having a primary amino group at the terminal (average molecular weight: about 5,000, manufactured by Jefferson Chemical Co., USA: Jeffamine T-50)
00) 17 g and reacted at room temperature for 5 minutes. Next, 10 g of isopropylamine was added and reacted at room temperature overnight (about 10 hours). The solvent was distilled off under reduced pressure to obtain "polymer compound IV" (polymer compound having sol-gel transition temperature).

1 g of "polymer compound IV" obtained above
Was dissolved in 9 g of distilled water under ice cooling. The sol-gel transition temperature of this aqueous solution was measured in the same manner as in Example 1, and the sol-gel transition temperature was 9 ° C.

Example 5 Polypropylene oxide having a primary amino group at one end (average molecular weight of about 2000, Jefferson Chemical Co., USA: Jeffamine M-2005) (20 g) was dissolved in carbon tetrachloride (50 ml), and then acrylic acid chloride ( Domestic Chemicals Co., Ltd. 0.91 g and triethylamine 1.
38 ml was added, and the mixture was reacted overnight at room temperature (about 10 hours). After separating the solid generated by the reaction by filtration,
The solvent was distilled off from the filtrate under reduced pressure to obtain a polypropylene oxide monoacrylamide compound having a polymerizable functional group introduced at one end.

10 g of the polypropylene oxide monoacrylamide body obtained above and 20 g of acrylamide
And are dissolved in 970 ml of distilled water in a reaction vessel under ice cooling,
After purging the inside of the reaction vessel with nitrogen, 0.3 g of ammonium persulfate and 200 μl of tetramethylethylenediamine were added, and the reaction was carried out overnight (about 10 hours) in an ice-cooled nitrogen atmosphere.

The reaction solution obtained was diluted to 3 liters with distilled water,
1 l at 10 ° C. using a hollow fiber type ultrafiltration membrane (H1P100-43 manufactured by Amicon) having a molecular weight cutoff of 100,000.
Concentrated. Dilute the concentrated solution with 2 l of distilled water,
The above dilution operation was performed again. The above-mentioned dilution and ultrafiltration concentration operations were repeated 5 times to remove those having a molecular weight of 100,000 or less. Those which have not been filtered by this ultrafiltration (those remaining in the ultrafiltration membrane) are collected and freeze-dried to form a polyacrylamide main chain with a side chain of polypropylene oxide having a molecular weight of 100,000 or more. "Polymer compound V" (polymer compound having sol-gel transition temperature)
27 g were obtained.

1 g of "polymer compound V" obtained as described above
Was dissolved in 9 g of distilled water under ice cooling. When the sol-gel transition temperature of this aqueous solution was measured in the same manner as in Example 1, the sol-gel transition temperature was 20 ° C.

Example 6 37 g of N-isopropylacrylamide, 3 g of n-butyl methacrylate, and polyethylene oxide monoacrylate (molecular weight 4,000, manufactured by NOF Corporation: P
ME-4000) (28 g) was dissolved in 340 ml of benzene, and then 2,2'-azobisisobutyronitrile (0.2 g) was added.
8 g was added and reacted at 60 ° C. for 6 hours. Chloroform (600 ml) was added to the obtained reaction product to dissolve it, and the solution was added dropwise to 20 L (liter) of ether to cause precipitation. The resulting precipitate was collected by filtration and the precipitate
After vacuum-drying at 24 ° C. for 24 hours, it was redissolved in 6 L of distilled water, and concentrated to 2 liters at 10 ° C. using a hollow fiber type ultrafiltration membrane (H1P100-43 manufactured by Amicon) having a cut-off molecular weight of 100,000. 4 l of distilled water was added to the concentrated solution to dilute it, and the above dilution operation was repeated. The above-mentioned dilution and ultrafiltration concentration operations were repeated 5 times to remove those having a molecular weight of 100,000 or less. What was not filtered by this ultrafiltration (remaining in the ultrafiltration membrane) was recovered and freeze-dried to obtain a "polymer compound VI" (polymer having a sol-gel transition temperature) having a molecular weight of 100,000 or more. Compound (60 g) was obtained.

1 g of "polymer compound VI" obtained above
Was dissolved in 9 g of distilled water under ice cooling. When the sol-gel transition temperature of this aqueous solution was measured in the same manner as in Example 1, the sol-gel transition temperature was 25 ° C.

Example 7 (Preparation of cosmetic pack) "Polymer compound having a sol-gel transition temperature of about 21 ° C synthesized in Example 2"
3 g of “II” was dissolved in 27 g of cold water to prepare an aqueous solution having a concentration of 10 wt%. It was observed that the aqueous solution of the polymer compound was in a viscous liquid state at 18 ° C. and when applied on the skin, gelled within 1 minute depending on the body temperature.

The coating film of the polymer compound thus gelled is different from the conventional cosmetic pack,
It could be easily peeled off from the skin even if it was not dried. When the coating film was peeled off from the skin about 10 minutes after the application, a refreshing feeling of the skin was obtained.

On the other hand, like the conventional cosmetic pack, the above gelled coating film was easily peeled off even after being sufficiently dried to form a coating film.

Example 8 (Preparation of cosmetic pack) 2.2 g of polyvinyl alcohol (average molecular weight: about 40,000, saponification degree: about 80 mol%) was heated (about 90 ° C.) in 40 g of water and stirred. It melt | dissolved below and prepared the polyvinyl alcohol aqueous solution whose density | concentration is about 5 wt%. Next, 3 g of “polymer compound II” having a sol-gel transition temperature of about 21 ° C. synthesized in Example 2 was dissolved in the polyvinyl alcohol aqueous solution under cooling and stirring to obtain polyvinyl alcohol (5 wt%). A mixed solution with "polymer compound II" (7 wt%) was prepared.

The mixed solution thus obtained was 18
It was found that it is a viscous liquid at ℃, can be easily and uniformly applied to the skin, and once applied on the skin, it immediately gels at body temperature.

The gelled film is a conventional cosmetic
Unlike the pack, it could be easily peeled from the skin without being dried. When the coating film was peeled from the skin about 20 minutes after the application, a refreshing feeling of the skin was obtained.

On the other hand, like the conventional cosmetic pack, the above gelled coating film was easily peeled off even after being sufficiently dried to form a thin coating film.

Example 9 (Preparation of depilatory) 5 g of calcium thioglycolate,
Mix with 7g of calcium hydroxide to make 100ml
Distilled water was added so as to be dissolved in the solution with stirring. To 100 ml of the aqueous solution thus obtained, about 7.5 g of “polymer compound II” having a sol-gel transition temperature of about 21 ° C. synthesized in Example 2 was added and dissolved under cooling to a concentration of An aqueous solution of about 7 wt% of "polymer compound II" was prepared and used as a depilatory.

The dehairing agent obtained as described above was in a fluid liquid state at about 18 ° C. and immediately gelled when applied on the skin. Approximately 5 ml of the depilatory is applied to the skin (legs, size =
The hair was removed by leaving it on the surface (about 5 cm × 5 cm) for 10 minutes. In the naked eye observation, the hair removal agent-disposed portion was satisfactorily dehaired.

After the above hair removal, the gel-like hair remover could be easily physically removed from the skin. No residue was visually observed on the skin after the peeling, and there was no need to wipe or wash the skin.

Example 10 (Preparation of decolorizing agent) 80 ml of hydrogen peroxide solution (concentration about 3%)
And 20 ml of strong ammonia water (specific gravity: about 0.90%) were mixed, distilled water was added so that the total amount became 100 ml, and the mixture was mixed with stirring. The sol of about 21 ° C. synthesized in Example 2 was added to 100 ml of the thus obtained aqueous solution.
About 7.5 g of "polymer compound II" having a gel transition temperature was added and dissolved under cooling to prepare an aqueous solution of "polymer compound II" having a concentration of about 7 wt% to prepare a decolorizing agent.

The decolorizing agent obtained above was in a fluid liquid state at about 18 ° C. and immediately gelled when applied on the skin. About 5 ml of the decolorizing agent is applied to the skin (leg, size =
Decolorization was carried out by leaving it on a sheet (about 5 cm × 5 cm) for 10 minutes. In the naked eye observation, the decolorizing agent-disposed portion was well decolorized.

After the above decolorization, the gel decolorizing agent could be easily physically peeled from the skin. No residue was visually observed on the skin after the peeling, and there was no need to wipe or wash the skin.

[0107]

As described above, according to the present invention, water and
A cosmetic base comprising at least a gel-forming component,
The gel-forming component consists of a polymer compound whose aqueous solution has a sol-gel transition temperature higher than 0 ° C. and lower than 37 ° C .; and, as a whole base, substantially water at a temperature higher than the sol-gel transition temperature. Provided is a cosmetic base which is insoluble and reversibly water-soluble at a temperature lower than the sol-gel transition temperature.

According to the present invention, there is further provided a cosmetic product which contains at least water and a gel-forming component; the gel-forming component having an aqueous solution whose sol-gel transition temperature is higher than 0 ° C and lower than 37 ° C. A fragrance for external use, which is composed of a polymer compound having: and is substantially water-insoluble at a temperature higher than the sol-gel transition temperature as a whole, and reversibly water-soluble at a temperature lower than the sol-gel transition temperature as a whole. Cosmetics are provided.

Since the external cosmetic composition of the present invention exhibits the special sol-gel transition behavior as described above, immediately before the cosmetic composition is applied to a living body (skin or the like) (for example, the temperature of the cosmetic composition is changed). Can be easily applied to a living body by coating or the like in a sol (liquid) state having high fluidity (by setting the temperature lower than the sol-gel transition temperature). After application to a living body, the temperature of the cosmetic itself rises due to body temperature and the like, so that the cosmetic quickly gels, so that a stable film can be rapidly formed on the living body.

On the other hand, when the cosmetic for external use is removed from the living body, for example, by returning the cosmetic to a sol state by lowering the temperature of the cosmetic, the removal from the living body becomes extremely easy and more complete. In other words, both the ease of application to the living body (and stability and rapidity) and the ease of removing the external use cosmetic from the living body, which were extremely difficult with conventional external use cosmetics, are compatible. It will be possible.

When the above-mentioned cosmetic for external use of the present invention is in the form of "cosmetic pack", the cosmetic pack has fluidity when applied to the skin and can be easily applied on the surface of the skin having complicated irregularities. Can be applied to the wrinkles and at the same time penetrate into the wrinkles. Further, once applied to the surface of the skin, the cosmetic pack of the present invention immediately changes into a gel state and remarkably improves the retention property on the skin. Further, peeling off of the cosmetic pack of the present invention does not require waiting for a long time until the water evaporates and a dry film is formed as in the case of the conventional cosmetic pack, and after application, a gelled film is immediately formed. In order to
Physical peeling is possible at any time. Furthermore, it is possible to change the gelled film into a sol state by using cold water and wash and remove it. Cosmetics of the invention like higher
Since the pack utilizes the gelation phenomenon due to body temperature, it is not necessary to add a low boiling point substance that causes excessive irritation to the skin like conventional cosmetic packs, but it also gives the skin flexibility, tension and moisture. It is possible to significantly increase the water content compared to conventional cosmetic packs.

The above-mentioned external cosmetic composition of the present invention is used as a "hair remover".
In the case of the form of "depigmenting agent", the depilatory agent / depigmenting agent has fluidity when applied to the skin, adheres to the skin having a complicated shape with irregularities, and penetrates into the pores. As a result, hair removal / bleaching effects are extremely high. Also once
When applied to the skin, the depilatory / bleaching agent of the present invention immediately changes into a gel state, so that the stickiness of the surface is remarkably reduced and accidental adhesion to clothing or the like can be very effectively prevented. In addition, after the hair removal / bleaching, the hair remover / bleaching agent of the present invention is gelated, and thus can be easily physically peeled from the skin. In particular, it can be easily removed from the pores, and the troublesome work of wiping or washing the skin like conventional hair removers / decolorants can be saved.

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Claims (14)

[Claims] 1. A cosmetic base comprising at least water and a gel-forming component; the gel-forming component being a polymer compound whose aqueous solution has a sol-gel transition temperature higher than 0 ° C. and lower than 37 ° C. And a scent that is substantially water-insoluble at a temperature higher than the sol-gel transition temperature and reversibly water-soluble at a temperature lower than the sol-gel transition temperature as a whole. Cosmetic base. 2. A cosmetic product comprising at least water and a gel-forming component; the gel-forming component having an aqueous solution thereof at 0 ° C.
A polymer compound having a sol-gel transition temperature higher than 37 ° C. and lower than 37 ° C .;
-A cosmetic for external use, which is substantially water-insoluble at a temperature higher than the gel transition temperature and reversibly water-soluble at a temperature lower than the sol-gel transition temperature. 3. A cosmetic pack as claimed in claim 2.
Topical cosmetics described. 4. The aqueous solution of the polymer compound is 0 ° C.
LCST (Lower Critical Sol)
3. The cosmetic preparation for external use according to claim 2, which is a polymer compound in which a temperature-sensitive polymer compound having a ution temperature (lower critical solution temperature) and a hydrophilic polymer compound are bonded. 5. The cosmetic preparation for external use according to claim 2, which further contains a water-soluble polymer compound. 6. The cosmetic preparation for external use according to claim 5, wherein the water-soluble polymer compound is polyvinyl alcohol. 7. The cosmetic preparation for external use according to claim 2, further comprising one or more components selected from a skin protecting agent, an antioxidant, a storage stabilizer, and a detergent. 8. The cosmetic for external use according to claim 2, which is a depilatory. 9. The cosmetic for external use according to claim 8, which further comprises a thioglycollate. 10. The cosmetic preparation for external use according to claim 8, which further contains calcium hydroxide or caustic alkali as a pH adjusting agent. 11. The cosmetic preparation for external use according to claim 8, which further contains urea and / or guanidine as an auxiliary agent. 12. The cosmetic for external use according to claim 2, further comprising a fragrance. 13. The cosmetic preparation for external use according to claim 2, which is a decolorizing agent. 14. The cosmetic preparation for external use according to claim 13, further comprising a mixture of hydrogen peroxide and ammonia.