JP2024033141A - warming cosmetics - Google Patents

Abstract

[Problem] A warming cosmetic that contains an oil-soluble active ingredient and provides a warming effect when applied to the skin, which improves the stability of the oil-soluble active ingredient and improves the effect of the oil-soluble active ingredient. To provide a warming cosmetic that can provide warmth. [Solution] (A) 40 to 99% by mass of glycerin, (B) 0.0001 to 50% by mass of oil-soluble active ingredients, (C) a structural unit based on 2-(meth)acryloyloxyethylphosphorylcholine and (meth) ) A warming cosmetic containing 0.01 to 10% by mass of a copolymer having a structural unit based on an alkyl acrylate. [Selection diagram] None

Description

The present invention relates to a warming cosmetic that contains an oil-soluble active ingredient and provides a warming effect when applied to the skin.

Skin care generally begins with hydration using lotions and uses cosmetics containing oil such as emulsions and creams to prevent skin dryness and roughness. In addition, cosmetics containing active ingredients are used to obtain beauty effects such as whitening and anti-wrinkle effects. In particular, oil-soluble active ingredients are widely used because they have high permeability into the skin. Various methods have been proposed for cosmetics in order to further enhance the effects of these active ingredients.
For example, Patent Document 1 describes that a vesicle composition in which a polyglycerol fatty acid ester and a polyol are combined is used to highly improve the permeability of an oil-soluble active ingredient into the skin and hair.
Further, Patent Document 2 describes a method of combining a specific cationic surfactant, nonionic surfactant, oil agent, and higher alcohol in order to increase the permeability of active ingredients such as Nile Red.

Further, as a method of enhancing the effect of the active ingredient, there is a method of promoting blood circulation in the user, and common methods include bathing and massage. Therefore, cosmetics containing oil-soluble active ingredients are required to be suitable for the massage process.
In addition, warming cosmetics that utilize the heat of hydration, such as polyhydric alcohols, warm the temperature of the skin to which they are applied, thereby making it possible to further enhance the effect of promoting blood circulation through massage.
Cosmetics that have a warming effect and are suitable for massage include those described in Patent Document 3, Patent Document 4, and the like.

However, cosmetics that contain oil-soluble active ingredients, have a warming effect, and are suitable for massage have not been sufficiently investigated. In particular, oil-soluble active ingredients are susceptible to deterioration in quality due to oxidation, such as odor, discoloration, and loss of functionality, and these are particularly accelerated by heat and light, so it is difficult to maintain the quality of oil-soluble active ingredients in cosmetics. is necessary.

Japanese Patent Application Publication No. 2018-199669 Japanese Patent Application Publication No. 2017-160236 Japanese Patent Application Publication No. 2013-180997 Japanese Patent Application Publication No. 2013-91619

The problem to be solved by the present invention is to provide a warming cosmetic that contains oil-soluble active ingredients and provides a warming effect when applied to the skin, in which the stability of the oil-soluble active ingredients is increased and the oil-soluble active ingredients An object of the present invention is to provide a warming cosmetic that can improve the effects of its ingredients.

In order to solve the above problems, the present inventors have made extensive studies and found that by incorporating a specific acrylic copolymer in a predetermined amount in a warming cosmetic containing a predetermined amount of glycerin and an oil-soluble active ingredient, The present invention has been completed based on the discovery that the above problems can be solved.

That is, the present invention comprises (A) 40 to 99% by mass of glycerin, (B) 0.0001 to 50% by mass of oil-soluble active ingredients, and (C) represented by the following formulas (1) and (2). It is a warming cosmetic containing 0.01 to 10% by mass of a copolymer having each structural unit.

（式中、Ｒ^１は水素原子またはメチル基を示す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group.)

（式中、Ｒ^２は水素原子またはメチル基を示し、ｍは３～２１の整数を示す。）

(In the formula, R ² represents a hydrogen atom or a methyl group, and m represents an integer from 3 to 21.)

The warming cosmetic of the present invention is a warming cosmetic that contains an oil-soluble active ingredient and provides a warming effect when applied to the skin. The effects of ingredients can be improved.

Embodiments of the present invention will be described below. Note that various changes can be made without departing from the gist of the present invention.
In addition, in this specification, the numerical range defined using the symbol "~" shall include the numerical values at both ends (upper limit and lower limit) of "~". For example, "2-4" represents 2 or more and 4 or less.

The warming cosmetic of the present invention contains at least each of the following components (A), (B), and (C). Each component will be explained below.
In addition, in this specification, the content of each component is the content when the total amount of the warming cosmetic of the present invention is 100% by mass. Furthermore, when a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total content of the plurality of substances present in the composition.

[Component (A)]
Component (A) used in the present invention is glycerin. Glycerin can be produced by a method in which an aqueous solution obtained by hydrolyzing fats and oils is purified by distillation or the like. Hereinafter, component (A) will also be referred to as glycerin (A).

The content of glycerin (A) in the warming cosmetic of the present invention is 40 to 99% by mass, preferably 45 to 97% by mass, more preferably 50 to 95% by mass, based on the total amount of the warming cosmetic. It is. If the content of glycerin (A) is too low, the warming effect may be weak and it may be difficult to enhance the effect of the oil-soluble active ingredient. Furthermore, if the content of glycerin (A) is too high, it may be difficult to obtain the effects of the oil-soluble active ingredient, and excessive stickiness may be felt, resulting in a poor feeling of use.

[Component (B)]
Component (B) used in the present invention is an oil-soluble active ingredient. "Oil-soluble" means that the solubility in water is extremely low, for example, the solubility in 100 g of water at room temperature (25 ° C.) is less than 1 g, or the octanol/water partition coefficient (Log Pow) is greater than 1. It means that. "Active ingredient" means the main ingredient that exhibits the desired action and effect. Hereinafter, component (B) will also be referred to as oil-soluble active ingredient (B).

The oil-soluble active ingredient (B) is not particularly limited, and includes vitamins such as ascorbyl monostearate, ascorbyl monopalmitate, ascorbyl dipalmitate, ascorbyl triisopalmitate, ascorbyl tetraisopalmitate, and ascorbyl tetrahexyldecanoate. Oil-soluble derivatives of C; vitamin E and its derivatives such as tocopherol and tocophenol acetate; vitamin A and its derivatives such as retinol, retinal, and retinol palmitate; ceramide or its analogs; stearyl glycyrrhetinate; isopropyl methylphenol; heparin analogs Examples include substances. Among these, vitamin A, vitamin C, vitamin E, and oil-soluble vitamins, which are derivatives thereof, are preferred because they are highly effective as active ingredients and whose quality easily deteriorates. One or more oil-soluble active ingredients (B) can be used.

The content of the oil-soluble active ingredient (B) in the warming cosmetic of the present invention is 0.0001 to 50% by mass, preferably 0.005 to 40% by mass, and more preferably 0.005 to 40% by mass, based on the total amount of the warming cosmetic. Preferably it is 0.001 to 30% by mass. If the content of the oil-soluble active ingredient (B) is too low, it may be difficult to obtain the effects of the oil-soluble active ingredient (B). Moreover, if the content of the oil-soluble active ingredient (B) is too high, the feeling of use may be lowered due to stickiness caused by the oil-soluble active ingredient (B), and the warming effect may be lowered.

[Component (C)]
Component (C) is a copolymer having structural units represented by the following formulas (1) and (2). Hereinafter, component (C) will also be referred to as copolymer (C).

（式中、Ｒ^１は水素原子またはメチル基を示す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group.)

The structural unit represented by the above formula (1) is a structural unit based on 2-(meth)acryloyloxyethylphosphorylcholine. Here, "(meth)acryloyl" means "acryloyl or methacryloyl."

（式中、Ｒ^２は水素原子またはメチル基を示し、ｍは３～２１の整数を示す。）

(In the formula, R ² represents a hydrogen atom or a methyl group, and m represents an integer from 3 to 21.)

The structural unit represented by the above formula (2) is a structural unit based on alkyl (meth)acrylate. Here, "(meth)acrylic acid" means "acrylic acid or methacrylic acid".
The alkyl group in the alkyl (meth)acrylate is a linear or branched alkyl group having 4 to 22 carbon atoms, such as butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, Examples include hexadecyl and octadecyl. Among these, linear alkyl groups such as butyl, octyl, decyl, dodecyl, and octadecyl are preferred, and octadecyl is more preferred.
m is an integer of 3 to 21, preferably 5 to 21, more preferably 10 to 21, still more preferably 15 to 20.

In the copolymer (C), the content ratio of the structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) (the structural unit represented by the formula (1)): [ The molar ratio of the structural unit represented by formula (2) (n1:n2) is preferably 9:1 to 1:9, more preferably 8:2 to 2:8.

If the ratio (n2/n1) (molar ratio) of the content of the structural unit represented by formula (2) to the content of the structural unit represented by formula (1) is too small, the potential of the oil-soluble active ingredient (B) will decrease. The solubilizing power may decrease, and the stability of the warming cosmetic may decrease. On the other hand, if the ratio (n2/n1) is too large, the hydrophobicity may be too high, resulting in a decrease in solubility in glycerin (A) and a decrease in the stability of the warming cosmetic.

The weight average molecular weight of the copolymer (C) is usually 10,000 to 1,000,000, preferably 30,000 to 900,000, more preferably 50,000 to 800,000, even more preferably is from 100,000 to 700,000, particularly preferably from 200,000 to 600,000. If the weight average molecular weight of the copolymer (C) is too low, the feeling of use may deteriorate and stickiness may occur, while on the other hand, if the weight average molecular weight of the copolymer (C) is too high, handling becomes difficult. Sometimes.
The weight average molecular weight of the copolymer (C) is measured by gel permeation chromatography (GPC) and is expressed as a molecular weight in terms of polyethylene glycol.

The polymerization form of the copolymer (C) is not particularly limited, and may be a random copolymer or a block copolymer, but a random copolymer is preferred.
The copolymer (C) is usually a binary copolymer consisting of a structural unit represented by the above formula (1) and a structural unit represented by the above formula (2), but the copolymer (C) In addition to the structural unit represented by formula (2), it may also be a copolymer containing other structural units.
Other structural units that may be included in the copolymer (C) are usually appropriately selected from those that can serve as structural units of the copolymer (C) within a range that does not affect the effects of the present invention. Can be done. Examples of monomers forming other structural units include (meth)acrylic esters having a lower alkyl group having 1 to 3 carbon atoms, such as methyl (meth)acrylate and ethyl (meth)acrylate; (meth)acrylic esters having a cyclic alkyl group such as cyclohexyl meth)acrylate; (meth)acrylic esters containing aromatic groups such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate; styrene; Examples include styrene monomers such as methylstyrene and chloromethylstyrene; vinyl ether monomers such as methyl vinyl ether and butyl vinyl ether; and vinyl ester monomers such as vinyl acetate and vinyl propionate.
These other structural units can contain one type or two or more types, and their content in the copolymer (C) is based on the total amount of the structural units represented by formula (1) and formula (2). On the other hand, it is preferably 40 mol% or less, more preferably 20 mol% or less.

Copolymer (C) can be produced by a production method known per se. For example, a monomer mixture containing 2-(meth)acryloyloxyethylphosphorylcholine and alkyl (meth)acrylate, and optionally monomers corresponding to the other structural units mentioned above, is added in the presence of a radical polymerization initiator. , in an inert gas atmosphere such as nitrogen, by a known method such as solution polymerization. The content ratio of each monomer at that time may be a ratio corresponding to the desired content ratio of each structural unit in the copolymer (C).

The warming cosmetic of the present invention can contain one selected from the above copolymers (C) alone or in combination of two or more. As the copolymer (C), those produced by the above polymerization method can also be used, but "Lipidure (registered trademark)-PMB (Ph10)" (polyquaternium-51), "Lipidure (registered trademark) -S" Commercially available products such as "Lipidure (registered trademark)-NR" (polyquaternium-61) (both manufactured by NOF Corporation) can also be used.

The content of the copolymer (C) in the warming cosmetic of the present invention is 0.01 to 10% by mass, preferably 0.1 to 7% by mass, more preferably is 0.5 to 5% by mass. If the content of the copolymer (C) is too low, the oil-soluble active ingredient (B) may not be sufficiently stabilized, and the thixotropic property of the warming cosmetic may become excessively high, resulting in a decrease in massage properties. . Moreover, if the content of the copolymer (C) is too large, the feeling of use may deteriorate.

The weight ratio (B/C) of the oil-soluble active ingredient (B) to the copolymer (C) is preferably 0.01 to 10, more preferably 0.1 to 7, even more preferably 0.5 to 5. 1 to 3 are particularly preferred. If the weight ratio (B/C) is too small, the amount of oil-soluble active ingredient (B) relative to copolymer (C) is too small, and it may be difficult to obtain the functions of oil-soluble active ingredient (B). If the weight ratio (B/C) is too large, the amount of copolymer (C) relative to the oil-soluble active ingredient (B) may be too small, resulting in insufficient stabilization of the oil-soluble active ingredient (B). .

[Warming cosmetics]
The warming cosmetic of the present invention contains at least the above glycerin (A), the oil-soluble active ingredient (B), and the copolymer (C), and the oil-soluble active ingredient (B) and the copolymer (C). forms oil droplets as aggregates, which are dispersed in the solvent glycerin (A).
It is preferable that the oil droplets made of the aggregate of the oil-soluble active ingredient (B) and the copolymer (C) have a particle size (D50) of 50% cumulative particle size distribution on a volume basis of 500 nm or less, and 300 nm or less. The thickness is more preferably 200 nm or less. In addition, the ratio D90/D10 of the particle size (D10) of the 10% cumulative particle size distribution and the particle size (D90) of the 90% cumulative particle size distribution on a volume basis is preferably 10 or less, more preferably 7 or less, and even more preferably 5 or less. . If the particle size (D50) or the ratio D90/D10 is too large, oil droplets tend to aggregate, which may reduce uniformity, and the stabilizing effect of the oil-soluble active ingredient (B) may not be sufficiently obtained. There is.
The particle size distribution of oil droplets made of an aggregate of the oil-soluble active ingredient (B) and the copolymer (C) can be measured using a commercially available particle size distribution meter. Measurement methods for particle size distribution include electron microscopy, atomic force microscopy, static light scattering, laser diffraction, dynamic light scattering, centrifugal sedimentation, electrical pulse measurement, chromatography, and ultrasonic attenuation. Various methods are known, and devices corresponding to each principle are commercially available. In order to measure the particle size distribution of primary particles of oil droplets, it is desirable to dilute the warming cosmetic material in water to an appropriate concentration and then perform the measurement.

(Thixotropic properties of warming cosmetics)
The warming cosmetic composition of the present invention preferably has low thixotropy from the viewpoint of suppressing dripping during massage and improving the feeling of thickness when applied. Thixotropy is expressed as the shear rate dependence of shear viscosity as a TI (thixotropy index) value, which is the ratio of two viscosity values measured under conditions of different rotational speeds. The TI value of the warming cosmetic is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. If the TI value is too high, the viscosity decreases significantly during massage, which may reduce usability.

(Other ingredients)
The warming cosmetic of the present invention is prepared with the above-mentioned components (A) to (C) as essential ingredients, but in addition to these essential ingredients, other ingredients commonly used in cosmetics may be added to the extent that the effects of the present invention are not impaired. Other ingredients may be added depending on the purpose.
Other ingredients as mentioned above include water, humectants, thickeners, plant extracts, colorants, antioxidants, pH adjusters, preservatives, chelating agents, and the like.
Among other components, the content of water is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.
The total content of glycerin (A), oil-soluble active ingredient (B), and copolymer (C) is preferably 90% by mass or more, more preferably 95% by mass based on the total amount of the warming cosmetic. % or more, more preferably 97% by mass or more.

(Method for preparing warming cosmetics)
The method for preparing the warming cosmetic of the present invention is not particularly limited, and in addition to ordinary emulsifying equipment such as a stirrer, impeller agitation, and homomixer, a Manton-Gorlin type high-pressure homogenizer, a jet water flow reversal type high-pressure emulsifier, and a microfluidizer can be used. High-pressure emulsifiers such as a nanomizer, a nanomizer, a starburst, and a wet atomizer can also be used, and one of these can be used alone or two or more can be combined to obtain the required particle size. From the viewpoint of reducing the particle size of the oil-soluble active ingredient (B), it is preferable to use a high-pressure emulsifier.

EXAMPLES Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited to these Examples in any way.

(Measurement of weight average molecular weight of polymer)
The weight average molecular weight was evaluated by gel permeation chromatography (GPC) using methanol/chloroform (weight ratio 4/6) as an eluent and monodisperse polymethyl methacrylate as a standard substance using refractive index detection.

(Synthesis of copolymer)
Synthesis example 1
3.57 g of MPC (2-methacryloyloxyethylphosphorylcholine) and 16.43 g of octadecyl methacrylate (C18MA) (monomer composition molar ratio, MPC/C18MA = 30/70) were dissolved in 180 g of n-butanol and placed in a four-necked flask. After blowing nitrogen for 30 minutes, 0.82 g of azobisisobutyronitrile was added at 60°C, and a polymerization reaction was carried out for 8 hours.
The polymerization solution was added dropwise to 3 liters of acetone with stirring, and the precipitate that precipitated was filtered and vacuum-dried at room temperature for 48 hours to obtain 15.8 g of powder. The obtained copolymer had a weight average molecular weight of 326,000. This was designated as Polymer 1.

(Synthesis of copolymer)
Synthesis examples 2 to 4
Polymers 2 to 4 were obtained in the same manner as in Synthesis Example 1, except that the type and composition ratio of the monomers were changed as shown in Table 1, and the same procedure as in Synthesis Example 1 was performed. Table 1 shows the composition ratio and weight average molecular weight of the obtained copolymer. Note that C2MA used in the synthesis of Polymer 3 is ethyl methacrylate.

(Preparation of warming cosmetic)
Example 1
Raw materials were blended to have the composition of Example 1 in Table 2 to prepare 100 g of a warming cosmetic. That is, the raw materials of Example 1 were placed in a container and pre-emulsified at room temperature using a tabletop homomixer (manufactured by Mizuho Kogyo Co., Ltd.). This was treated twice at room temperature using a Systemizer (C17, manufactured by Mutual) at a pressure of 180 MPa to obtain a warming cosmetic.

Examples 2-4, Comparative Examples 1-4
It was prepared in the same manner as in Example 1.

Example 5
The raw materials of Example 5 were placed in a container and heated at room temperature using a tabletop homomixer (manufactured by Mizuho Kogyo Co., Ltd.) to obtain a warming cosmetic.

Regarding the warming cosmetics obtained in the above Examples and Comparative Examples, particle size distribution measurements were performed as described below, and the following evaluations were also performed. In addition, below, an oil-soluble active ingredient may be described as an oil agent.

(Particle size of 0.1% aqueous solution of warming cosmetic)
0.1 g of the obtained warming cosmetic and 9.9 g of purified water were placed in a 10 g screw tube and stirred to prepare a 0.1% aqueous solution of the warming cosmetic. The particle size distribution of the obtained aqueous solution was measured. A particle size/molecular weight measuring system (manufactured by Otsuka Electronics, ELSZ-2000) was used to measure the particle size distribution.
Table 2 shows the particle size of the volume-based 10% cumulative particle size distribution (D10), the particle size of the volume-based 50% cumulative particle size distribution (D50), and the particle size of the 90% cumulative particle size distribution (D90), as well as the ratio D90/ Indicates D10.

(Warm sensation when using warming cosmetics)
A panel of 20 women evaluated the feeling of warmth when the warming cosmetic was applied around the outer corners of the eyes as follows.
2 points: I felt that there was a sufficient sense of warmth.
1 point: I felt that there was a somewhat sufficient sense of warmth.
0 points: The sense of warmth was felt to be insufficient.
The total score of the 20 participants was calculated and evaluated based on the following criteria and displayed in the table.
◎: There is no panelist who gave a total score of 35 points or more and gave an evaluation of 0 points.
○: There is a panelist who gave an evaluation with a total score of 30 points or more and less than 35 points, or a total score of 35 points or more and 0 points.
Δ: Total score is 20 points or more and less than 30 points.
×: Total score is less than 20 points.

(Evaluation of residual rate of oil based on fluorescent exposure of warming cosmetics)
10 g of the obtained warming cosmetic was stored in a screw tube and stored at 25° C. in an illuminated incubator (EYELA FLZ-2000). They were taken out one day and three days after the start of storage, and the amount of oil-soluble active ingredient was measured by HPLC.
The amount of oil before the start of storage was taken as the residual rate of the oil, and the residual rate was evaluated as follows. The survival rate was rounded to the first decimal place to give an integer value.
<Survival rate after 1 day of storage>
◎: 80% or more remained.
○: 70 to 79% remained.
△: 60-69% remained.
×: 59% or less remained.
<Survival rate after 3 days of storage>
◎: 55% or more remained.
○: 45-54% remained.
△: 35-44% remained.
×: 34% or less remained.

(Thixotropic properties of warming cosmetics)
Using a rheometer (MCR302 manufactured by Anton Paar), the shear viscosity at a shear rate of 10/s and 500/s was measured at 25° C., and the TI value was calculated from the following formula.
TI value = (shear viscosity at 10/s (mPa s))/(shear viscosity at 500/s (mPa s))

(Evaluation of residual rate of oil agent by sunlight exposure of 1% aqueous solution of warming cosmetic)
1 g of the obtained warming cosmetic and 9 g of purified water were placed in a 10 g screw tube and stirred to prepare a 1% aqueous solution of the warming cosmetic. This was placed on a windowsill exposed to direct sunlight. The samples were taken out 30 minutes and 60 minutes after the start of standing, and the amount of oil-soluble active ingredient was measured by HPLC (Lachrom ELITE, manufactured by Hitachi, Ltd.).
The amount of oil agent before the start of standing was defined as the residual rate of the oil agent, and the residual rate was evaluated as follows. The survival rate was rounded to the first decimal place to give an integer value.
<Survival rate after 30 minutes of standing>
◎: 70% or more remained.
○: 60-69% remained.
Δ: 50 to 59% remained.
x: 49% or less remained.
<Survival rate after 60 minutes of standing>
◎: 40% or more remained.
○: 35-39% remained.
△: 30 to 34% remained.
×: 29% or less remained.

(Evaluation of the feeling of use of a 1% aqueous solution of warming cosmetics)
1 g of the obtained warming cosmetic and 9 g of purified water were placed in a 10 g screw tube and stirred to prepare a 1% aqueous solution of the warming cosmetic. Twenty panelists (25 to 45 years old, 10 men and women each) applied the resulting aqueous solution (approximately 1 g) over their entire face and evaluated the stickiness after use using the following criteria. In detail, if the total score of 20 people is 35 points or more, it will be marked "◎" (excellent), if the score is between 25 points and 34 points, it will be marked "○" (good), and if the score is between 15 points and 24 points, it will be marked "△". (Acceptable), and cases with 14 points or less were marked as "x" (poor).
2 points: If there is no creaking and the product feels fresh after use.
1 point: If there is little squeak and the product feels a little fresh after use.
0 points: After use, there was a squeak and no freshness was felt.

(Evaluation of transmittance of 0.1% aqueous solution of warming cosmetic)
0.1 g of the obtained warming cosmetic and 9.9 g of purified water were placed in a 10 g screw tube and stirred to prepare a 0.1% aqueous solution of the warming cosmetic. The transmittance of the obtained aqueous solution was measured and evaluated according to the following criteria. A UV-visible spectrophotometer (manufactured by Hitachi, Ltd., U-3010) was used to measure the transmittance.
◎: Transmittance was 75% or more.
○: Transmittance was 50% or more and less than 75%.
Δ: Transmittance was 25% or more and less than 50%.
×: Transmittance was less than 25%.

*1: Manufactured by BASF, Retinol 15D (15:85 solution of retinol and tri(caprylic acid/capric acid) glyceryl)
*2: NOFABLE ESO-8520 manufactured by NOF Corporation

The warming cosmetics of Examples 1 to 5 provide a warming sensation when applied, maintain the quality of retinol, an oil-soluble active ingredient, even when exposed to fluorescent light or sunlight, and do not feel sticky after use. There was no problem and the usability was good.
On the other hand, in Comparative Examples 1 to 3, since the copolymer (C) was different from that specified in Claim 1, the quality of retinol deteriorated when exposed to fluorescent lamps or sunlight, and the usability was also poor. The same was true for Comparative Example 4 in which the content of copolymer (C) was too low.

The warming cosmetic of the present invention not only provides a warming effect when applied to the skin, but also maintains the quality of the oil-soluble active ingredients used to obtain beauty effects such as whitening and anti-wrinkle. It can be suitably used in creams, facial cleansing creams, packs, etc.

Claims (1)

(A) 40 to 99% by mass of glycerin;
(B) 0.0001 to 50% by mass of oil-soluble active ingredients;
(C) A warming cosmetic containing 0.01 to 10% by mass of a copolymer having each structural unit represented by the following formulas (1) and (2).

(In the formula, R ¹ represents a hydrogen atom or a methyl group.)

(In the formula, R ² represents a hydrogen atom or a methyl group, and m represents an integer from 3 to 21.)