JP2000226325A - Sheet cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheet cosmetic having high adhesion to skin, clear appearance, no feeling of incompatibility when sticking on skin and heat-reserving and cooling effects by consisting of one hydrous gel layer sheet without any support and having a transmissivity of a specified value or more. SOLUTION: This sheet cosmetic comprises one hydrous layer sheet having no support and the sheet of 1 mm thickness has >=70%, preferably >=80%, more preferably >=85% transmissivity. The sheet cosmetic preferably has adhesive force of 1-100 times its own weight, more preferably 1-90 times its own weight, especially preferably 1-50 times its own weight, and <=1,000 g/cm2 more preferably 200-1,000 g/cm2, especially preferably 200-800 g/cm2 jelly strength. As a material for forming such a gel, the one having above properties and selected from agar, mannan, gelatin or the like (e.g. an agar component extracted from 1-10 wt.% sulfate radical-containing seaweed with a neutral hot-water) can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a water-containing gel in the form of a sheet without a support layer, which has high adhesiveness to the skin, has a transparent appearance, has no uncomfortable feeling when applied to the skin, and has high skin contact. The present invention relates to a sheet cosmetic having a moisturizing effect and a cooling effect.

[0002]

2. Description of the Related Art
As a sheet-shaped cosmetic used by being adhered to the skin, there are known those in which a gel-like composition containing a component having a moisturizing action and a whitening effect is applied or impregnated on a sheet-like support. These are intended to impart strength and shape retention to the sheet-like support to the sheet-like support, to allow the active ingredient in the composition to be applied or impregnated to the skin to penetrate the skin, and to improve the smoothness of the skin. Used in anticipation of effect.

[0003] As a material of the sheet-like support layer, generally,
A woven fabric or a nonwoven fabric is used, but when the gel composition is applied or impregnated with the woven fabric or the nonwoven fabric, the sheet becomes thick, the feeling of discomfort is large, and there is no transparent appearance.

On the other hand, materials for the gel composition to be applied or impregnated on these substrates include collagen, alginic acid,
Natural polymer materials such as pullulan and synthetic polymer materials such as cross-linked polyacrylate are used. Among these, natural polymers such as collagen and alginic acid have high solubility in lotions and the like, and thus have poor shape retention as cosmetics, and a large amount of sheet components remain on the skin, so that they can be touched. There were problems such as stickiness. In addition, in order to solve the problem that the feeling of adhesion to the skin is weak, adhesive components such as polyvinylpyrrolidone, polyvinyl alcohol, and polyacrylic acid salt are blended, and these are configured as an adhesive surface layer. However, there is a problem in that the penetration of the active ingredient is inhibited or stickiness occurs.

[0005]

As a result of various studies on the mechanical and optical properties of materials used for sheet cosmetics, the present inventors have found that they have high adhesion to the skin, have a transparent appearance,
A composition that does not cause discomfort even when affixed to the skin was found.

[0006] The present invention provides a sheet cosmetic comprising a sheet of a hydrogel having no support layer and having a light transmittance of 70% or more in a sheet having a thickness of 1 mm.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The sheet cosmetic of the present invention comprises one sheet of a hydrogel having no support layer. Conventional sheet cosmetics have a support layer such as a woven cloth or a nonwoven cloth, and are thereby adhered to the skin.However, the sheet cosmetics of the present invention are such that one layer of hydrogel itself becomes a sheet. And does not have such a support layer.

The sheet cosmetic of the present invention has a light transmittance of 70% or more, preferably 80% or more, particularly preferably 85% or more in a sheet having a thickness of 1 mm. Light transmittance is 70
%, A transparent appearance cannot be obtained, and when applied to the skin, a sense of incongruity is large. Here, the light transmittance is 550 wavelength.
The light transmittance in nm can be measured using, for example, a UV measuring device UV-3100PC manufactured by Shimadzu Corporation.

The sheet cosmetic of the present invention has a weight of 1 to 10%.
Those having an adhesive strength of 0 times, more preferably 1 to 90 times, especially 1 to 50 times are preferable. If the adhesive strength is less than 1 time of its own weight, it will not be able to be retained even when applied to the skin, and it will easily fall off.
If it exceeds 00 times, the feeling of discomfort when affixed to the skin is large, and the skin may be irritated when peeled off. Here, the adhesive strength can be evaluated by using a circular parallel plate having a diameter of 8 mm made of polyethylene to adhere for 10 seconds with a force of 10 g and then measuring the force when peeling off at a constant speed (1 mm / sec).

It is preferable that the sheet cosmetic of the present invention does not have an adhesive layer or an adhesive component, and exhibits the above-mentioned adhesive strength as a single sheet of hydrogel. Here, the adhesive layer refers to a layer containing an adhesive component such as polyvinylpyrrolidone, polyvinyl alcohol, and polyacrylate. In conventional sheet cosmetics, the gel component itself has a weak adhesive force and cannot be held on the skin by itself. Therefore, the adhesive is adhered to the skin by using the adhesive component as described above to increase the adhesive force. The sheet cosmetic of the present invention can be formed of a material having the above-mentioned adhesive strength without such an adhesive layer or an adhesive component.

The sheet cosmetic of the present invention has a jelly strength of 1
000 g / cm ² or less, particularly 200 to 1000 g / cm ² ,
Further, it is preferably 200 to 800 g / cm ² , because the feeling of discomfort when applied to the skin is less. Here, the jelly strength is measured as follows.

(1) Measuring device Rheometer: RE-3305 (manufactured by Yamaden Corporation) Plunger: cylindrical plunger, diameter 5 mm Sample stage descending speed: 0.5 mm / sec

(2) Preparation of Sample A sample of a sheet cosmetic is placed on a sample stage.

(3) Measurement of jelly strength The force received from the jelly by the cylindrical plunger lowered at a constant speed (0.5 mm / sec) was observed, and the strength at which the jelly broke was defined as the jelly strength.

[0015] Such gel-forming materials include agar,
Among mannans, gelatins and the like, those having the above properties can be selected and used. For example, an agar component (A) obtained by extracting a raw seaweed having a sulfate content of 1 to 10% with neutral hot water and having a jelly strength of 600 g / cm ² or less in a gel having an agar concentration of 1.5% by weight. Can be used.

Such an agar component (A) is obtained by extracting from a raw seaweed having a sulfate content of 1 to 10%. Examples of the raw seaweed include Ogonori, Amakusa, and Obakusa.
As an extraction means, extraction with neutral hot water is preferable in order to obtain agar having desired physical properties.

The gel strength of the agar component (A) at 1.5% by weight agar concentration is preferably 600 g / cm ² or less, which is relatively lower than that of ordinary agar, from the viewpoint of usability. More preferably 10 to 600 g / cm ² , especially 10 to
400 g / cm ² . Here, the jelly strength is measured as follows using the same measuring device as described above.

(1) Preparation of sample 1) 3.0 g of an agar sample is precisely weighed, placed in a tared container (0.5 L capacity), and 50 mL of ion-exchanged water is added to absorb water sufficiently. 2) Add warm ion exchanged water to make the content about 210g,
Heat and dissolve in a hot water bath for 15 minutes. 3) Adjust the content to 200.0 g, and pour it into a glass container having an inner diameter of 49 mm and a depth of 57 mm wound with a tape as shown in FIG. 4) Allow to cool at room temperature for 1 hour, cover and leave in a constant temperature room at 20 ° C. overnight.

(2) Measurement of jelly strength The tape is removed, and the jelly on the edge of the container is cut with a cutter. Using the cut surface of the obtained 1.5% by weight water gel as a sample, the strength is measured with a rheometer.

The agar component (A) has a viscosity of 15 mPa.s at 85 ° C. in a sol having an agar concentration of 1.5% by weight.
S or more, especially 15 to 200 mPa · s, is preferable in terms of handling in production. The agar component (A)
Is more preferably from 400,000 to 2,000,000. Further, as the agar component (A), the time until the initial stress is reduced to half in a 20% deformation stress relaxation measurement in a 1.5% by weight agar concentration and a 1 mm thick gel is 8 seconds (s) or more, particularly 8 to 15%. Seconds (s) are preferred from the viewpoint of shape retention. That is, if the stress relaxation time is short, deformation is likely to occur and the shape retention is poor, but if the time is 8 seconds or more, the shape retention is good. Here, the stress relaxation time can be obtained by measuring the stress relaxation time when 20% compression deformation is performed using a circular parallel plate having a diameter of 4.75 mm using RSA2 manufactured by Rheometrics.

The compounding amount of the gel-forming material including the agar component (A) is preferably 0.01 to 5% by weight, particularly 0.1 to 3% by weight in the sheet cosmetics in view of strength and feeling of use. . The balance is water and other ingredients as listed below.

The strength and storage stability of the sheet cosmetic of the present invention can be improved by further blending another water-soluble polymer (B). As the water-soluble polymer,
The polymer may be any of natural and synthetic, and includes a polymer having a hydrophilic group such as a hydroxyl group, an ethylene oxide group or an amide group, and a polymer having a hydroxyl group is particularly preferable. For example, polysaccharides, natural macromolecules such as proteins and synthetic macromolecules, and specifically, as polysaccharides,
Cationized cellulose, carboxymethyl cellulose,
Hydroxyethyl cellulose, starch, ionized starch derivatives, starch and block polymers of synthetic polymers,
Hyaluronic acid, carrageenan, xanthan gum, chitin, chitosan, pullulan, tuberose polysaccharide, alginic acid, etc .; proteins include keratin, albumin, collagen, etc .; synthetic polymers include polyvinyl alcohols and derivatives thereof, and modified silicone. And various latexes. Of these,
Polysaccharides are more preferred.

The amount of the water-soluble polymer (B) in the sheet cosmetic is preferably 0.001 to 50% by weight, more preferably 0.01 to 10% by weight.

In the present invention, a humectant (C) can be further used. Examples of such humectants include ethanol, glycerin, ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, diglycerin, polyglycerin such as triglycerin, glucose, and the like.
Examples include maltose, maltitol, sucrose, fructose, threitol, erythritol, starch-degrading sugar and the like. Among them, ethanol, 1,3-butylene glycol, and glycerin are particularly preferable from the viewpoint of feeling of use.

Here, the compounding amount of the humectant (C) is preferably 0.001 to 40% by weight in the sheet cosmetic, and 0.01 to 40% by weight.
-30% by weight is particularly preferred.

The sheet cosmetic of the present invention contains, in addition to the above components, organic acids, oils, sterols, surfactants, powders, silicones, inorganic salts, preservatives, pH adjusters, ultraviolet absorbers, pigments , A medicinal ingredient, a fragrance, and the like.

The sheet cosmetic of the present invention is prepared by, for example, dissolving a gel-forming material together with other components in warm water and pouring it into a mold to lower the temperature below the gelling temperature, or similarly forming a large-area sheet. Then, it can be manufactured into a sheet by punching it into a desired mold.

The sheet cosmetic of the present invention has a thickness of 0.1 to
It is preferably 5 mm, especially 0.5 to 2 mm,
Less discomfort when applied to the skin, more preferred.

The shape of the sheet is not particularly limited. For example, in order to enhance the skin adhesion, the sheet conforms to the shape of each application site. Any shape such as a shape with a hole in the corresponding portion, or a cloud shape or a broad bean shape when pasted under the eyes can be used.

[0030] The sheet cosmetic of the present invention has a cooling effect due to evaporation of water when applied to the skin. For example, when a hydrogel is formed into a sheet having a thickness of 1 mm and peeled off after being applied on the skin for 10 minutes, the skin surface temperature can be lowered by 3 ° C. or more. Here, the skin surface temperature is measured by a radiation type surface thermometer (manufactured by TASCO, THI-500).

The sheet cosmetic of the present invention can be used, for example, by directly applying it to the skin after face washing, or by applying another cosmetic to the skin and then applying it to the application site. Further, other cosmetics can be used after being applied or impregnated to the sheet cosmetic of the present invention.

After the sheet cosmetic of the present invention is applied to the skin,
Since there is no support layer, the sheet shrinks on the skin due to the evaporation of moisture, and the shape of the skin can be changed, which has the effect of improving wrinkles and pulling the skin. The shrinkage of the sheet at this time is preferably 3% or more of the total surface area, particularly 3 to 20%, and more preferably 3 to 10%, because the skin condition can be naturally corrected. Here, the shrinkage of the sheet is 2 cm
A sheet having a size of 2 cm and a thickness of 1 mm was stuck on the skin (cheek) at room temperature, and the amount of change in length after 10 minutes was measured and calculated using a caliper.

Conventionally, as a sheet-like cosmetic for correcting wrinkles, there has been known, for example, a sheet-like cosmetic which is fixed in a state where wrinkles are stretched, as disclosed in Japanese Patent Application Laid-Open No. 9-143026. However, it is difficult to apply it to necessary parts with such a corrector, such as the skin that has been deformed by one's own hands when the sheet is applied, and it is difficult to apply it to necessary parts. there were. On the other hand, if the sheet cosmetic of the present invention is used, the shape of the skin can be easily changed.

[0034]

EXAMPLES Example 1 Sheet cosmetics shown in Table 1 were prepared, and the feeling of adhesion to the skin was evaluated. Table 1 shows the results. For a and b in Table 1, 1.5% of agar was dissolved in a commercially available lotion and molded into a 1.2 mm thick sheet to obtain samples. Incidentally, the jelly strength at 1.5 wt% concentration of the gel of agar used in a and b were respectively ^{415g / cm 2, 610g / cm} 2. Further, the same commercial lotion was impregnated into the mannan sheet (c), the nonwoven fabric (d) and the pullulan sheet (e).

(Evaluation Method) (1) Feeling of Skin Adhesion: After hydrogel was applied to the face, 10
The feeling of skin adhesion for 10 minutes was evaluated by 10 panelists. ；: 7 or more persons answered that there was no uncomfortable feeling and the feeling of skin adhesion was high. Δ: 4 to 6 persons answered that there was no uncomfortable feeling and the feeling of skin adhesion was high. ×: 3 or less answered that there was no uncomfortable feeling and the feeling of skin adhesion was high.

(2) Adhesive force Using a tacking tester TAC2 manufactured by RHESCA,
The measurement was performed under the above conditions. (3) Jelly strength As described above. (4) Stress relaxation time As described above. (5) Light transmittance As described above.

[0037]

[Table 1]

As is evident from the results in Table 1, the sheet cosmetics of the present invention (sheets a and c) had high light transmittance and good skin adhesion. The shrinkage of the polyacrylic acid gel and the gelatin gel was measured to be 2.1% and 1.5%, respectively. The shrinkage of the sheet cosmetic of the present invention was particularly good.

Example 2 The skin moisture content and skin condition when the sheet cosmetic of the present invention was used were evaluated. That is, the sheet of the present invention (sheet a in Example 1) or a comparative sheet (polyacrylic acid gel sheet cosmetic using a nonwoven fabric, 2 mm thick) was adhered to the skin, left for 15 minutes, and then peeled off. The measurement is 20
℃, 15% relative humidity in dry conditions.
The values were shown as relative values based on the serum using SKYCON-200 (manufactured by IBS). In addition, the state of the skin (texture) is observed by magnifying the skin with a microscope, performing a visual judgment by a specialist, comparing the condition of the skin with the texture before application, and when the texture is improved,場合 If it is slightly improved,
The case where there was no change was indicated by x. Table 2 shows the results.

[0040]

[Table 2]

From the results shown in Table 2, it was confirmed that when the sheet cosmetic of the present invention was used, the effect on the skin moisture content and skin condition was improved.

Example 3 The effect of promoting penetration of a water-soluble component (amino acid) when the sheet cosmetic of the present invention was used was evaluated. Amino acids were added to the sheet of the present invention or the comparative sheet (each sheet of Example 2), and this was affixed to pigskin skin. After 18 hours, the amount of amino acids permeated into the pigskin was measured. The relative values when the permeation amount of the sheet cosmetic of the present invention was set to 1 were shown. Table 3 shows the results.

[0043]

[Table 3]

From the results shown in Table 3, when the sheet cosmetic of the present invention was used, the effect of promoting the penetration of amino acids was enhanced.

Example 4 The effect of cooling the skin when using the sheet cosmetic of the present invention was evaluated. The sheet of the present invention or the comparative sheet (each sheet of Example 2) was adhered to the face for 10 minutes and then removed, and the cooling effect was evaluated by monitoring the skin temperature thereafter. An example in which the lotion was only applied to the face was also evaluated.
The measurement was performed with a radiation thermometer (THI-500, manufactured by Tasco). Table 4 shows the results.

[0046]

[Table 4]

From the results shown in Table 4, when the sheet cosmetic of the present invention was used, the skin cooling effect was improved.

[0048]

Industrial Applicability The sheet cosmetic of the present invention is in the form of a sheet as a hydrogel even without a support layer, has high adhesion to the skin, is transparent in appearance, and has no uncomfortable feeling when applied to the skin. In addition, it is suitable for sticking to the skin, has a large shape-retaining property, is excellent in the effect of keeping the skin warm and cool, and can shrink by drying to change the shape of the skin.

[Brief description of the drawings]

FIG. 1 is a view showing a sample container and a cut surface when measuring the jelly strength of agar.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61K 7/00 A61K 7/00 J A61P 17/16 A61P 17/16

Claims (6)

[Claims] 1. A sheet having a thickness of 1 mm, comprising a sheet of a hydrogel having no support layer and having a light transmittance of 70%.
% Sheet cosmetics. 2. The sheet cosmetic according to claim 1, which has an adhesive strength of 1 to 100 times its own weight. 3. The sheet cosmetic according to claim 1, wherein the jelly strength is 1000 g / cm ² or less. 4. An agar obtained by extracting a raw seaweed having a sulfate content of 1 to 10% with neutral hot water and having a gel strength of 1.5% by weight agar having a jelly strength of 600 g / cm ² or less. The sheet cosmetic according to any one of claims 1 to 3, further comprising component (A). 5. The sheet cosmetic according to claim 4, further comprising another water-soluble polymer (B). 6. The sheet cosmetic according to claim 4, further comprising a humectant (C).