JPH1062338A - Evaluation method of makeup cosmetics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clarify the optical theory that the texture of the skin can appear to make the skin look beautiful, and provide an evaluation method of makeup cosmetics for making the skin look beautiful. SOLUTION: A light having a wavelength range of visual light is emitted to a surface having a makeup cosmetics applied thereto from at least two directions having different incident angle to the surface, and spectra of a plurality of reflected lights obtained from the irradiated lights are measured, and the spectral patterns are mutually compared to evaluate the makeup cosmetics. MAX-RAO value is calculated from the difference in reflectance of the reflected lights, particularly, when a visual light within a wavelength range of 400-700nm is irradiated from two different directions, and the comparison of spectral patterns is performed with the MAX-RAO value as index.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating a makeup cosmetic suitable for evaluating a foundation.

[0002]

2. Description of the Related Art It is not only women but everyone who wants to be seen beautifully by others. Various cosmetics have been developed to satisfy such needs. Of which
For example, there may be mentioned a basic cosmetic for enhancing the function of the skin and a makeup cosmetic for decorating with an optical effect. Of these cosmetics, the one that seems to have contributed most to making it look beautiful is makeup cosmetics, and consumers are one of the major motivators when using makeup cosmetics. It is listed.

[0003] However, the use of makeup cosmetics is often determined by the experience and taste of each individual, and scientific guidelines on the use have been greatly improved in recent years. Nevertheless, it is still not enough.

[0004] In particular, it is already known that a foundation contains an element that makes the skin look beautiful in addition to its physical properties such as color and hiding power. A technique was developed to make the skin look beautiful. However, it has to be said that the optical action and the mechanism that looks beautiful have not been fully explored.

[0005] That is, there has been a demand for the development of an evaluation method for makeup cosmetics represented by a beautiful-looking theory and a foundation utilizing the same.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such circumstances, and clarifies the theory that makes human skin look beautiful, as well as objective makeup makeup that does not depend on experience or subjectivity. It is an object to provide a method for evaluating fees.

[0007]

In view of such circumstances, the present inventors have conducted intensive studies to elucidate the optical mechanism that makes human skin look beautiful. As a result, the texture of human skin appears. Found that one of the major factors that looks beautiful is the optical effect derived from the translucency of the stratum corneum.

Since the stratum corneum is translucent, almost all visible light incident on the skin at a steep angle close to 90 degrees is reflected, but visible light incident at a shallow angle close to 0 degrees is absorbed or scattered. The reflected light will be reflected at a different wavelength configuration from the irradiation light, and the subtle differences in the spectrum of the reflected light will give skin texture as a factor other than physical characteristics such as color and hiding power and look beautiful. To make a significant contribution to

The following MAX-R is used as an optical characteristic value expressing the difference in the spectrum of the reflected light.
It has been found that the AO value is suitably used.

[0010] That is, the evaluation method of the present invention is a method of evaluating a make-up cosmetic, in which light having a visible light wavelength range is incident on the surface on which the make-up cosmetic is applied, with respect to the surface. Irradiating from at least two different directions, measuring the spectra of a plurality of reflected lights obtained from the irradiating light, and comparing the spectrum patterns with each other.

Here, the irradiation light preferably includes visible light having an incident angle of 10 to 60 degrees with respect to the surface and visible light having an incident angle of 75 to 90 degrees with respect to the surface. The wavelength range of the irradiation light is preferably 400 to 700 nm. The spectra of the plurality of reflected lights are preferably measured independently of each other. Further, the irradiation light is preferably applied to the surface from two directions having different incident angles with respect to the surface, and more preferably, the irradiation light from the two directions is
Visible light having an incident angle of 10 to 60 degrees with respect to the surface and visible light having an incident angle of 75 to 90 degrees with respect to the surface.

Further, a preferable evaluation method of the present invention is that, in the comparison of the spectral patterns, the wavelength range of 400
The surface is irradiated with visible light of about 700 nm from two directions having different incident angles with respect to the surface, the spectra of two reflected lights obtained from the irradiated light are measured, and the reflection of the spectrum of each reflected light in the wavelength range is performed. A MAX-RAO value is calculated from the ratio by the following equation (I), and the comparison is performed using the MAX-RAO value as an index.

[0013]

MAX-RAO = [(BA) / A] _max (I)

(Where A represents the reflectance of reflected light with respect to irradiation light having a larger incident angle with respect to the surface, and B represents the reflectance of reflected light with respect to irradiation light having a smaller incidence angle with respect to the surface. ( _BA ) / A] _max represents the maximum value of ( _BA ) / A in the above wavelength range.)

The MAX-RAO value is obtained by irradiating the irradiated surface with make-up with light having a wavelength range of visible light from two directions having different angles with respect to the irradiated surface, measuring the spectrum of the reflected light, and measuring each wavelength. [(Reflectance of reflected light with respect to irradiation light having a smaller incident angle with respect to the surface)]
− (Reflectance of reflected light with respect to irradiation light having a larger incident angle to the surface) / (reflectance of reflected light with respect to irradiation light having a larger incident angle to the surface)] in the measurement wavelength range.

The present invention relates to the MAX thus obtained.
-It has been completed as a result of finding that the RAO value can be used as an index for evaluating the degree to which makeup cosmetics look natural and beautiful.

In the present invention, the makeup cosmetic is preferably a foundation.

[0018]

Embodiments of the present invention will be described below. The most preferred embodiment of the method for evaluating a makeup cosmetic of the present invention is performed according to the following steps.

1) Visible light is irradiated from one direction to the makeup-applied surface, and the spectrum of the reflected light obtained is measured. Here, the surface on which the makeup is applied is not particularly limited, but it is preferable to perform the measurement after applying the makeup on human skin, since an appropriate evaluation result can be obtained.

2) Visible light is irradiated at an angle different from the direction of 1), and the spectrum of the reflected light is measured in the same manner.
At this time, the incident angle of the visible light to be applied in 1) and 2) with respect to the makeup surface is 0 to 60 degrees, more preferably 10 to 60 degrees, still more preferably 15 to 60 degrees, and the other is 75 to 60 degrees. ~ 90 degrees, more preferably 78-90
Degrees, more preferably 80 to 90 degrees. This is because the reflected light of the incident light which is close to the vertical direction is almost a direct reflection, and the reflected light of the incident light which is close to the horizontal direction is scattered and absorbed most, thereby significantly different from the incident light. This is because the optical characteristics of the reflection surface can be grasped by comparing.

3) The spectral spectra of the two reflected lights thus obtained are compared with each other.

FIGS. 1 to 3 show spectral spectra of reflected light when the skin is irradiated with light of various wavelengths at incident angles of 40 ° and 85 ° and measured. FIG. 1 shows normal skin (untreated skin of panelists determined to be beautiful skin by visual observation),
FIG. 2 shows a spectral spectrum when a foundation (mat type foundation) that gives a thick feeling to the panelist is applied, and FIG. 3 shows a spectral spectrum when the skin color standard plate is used. In the drawing, the dotted line indicates the case where the incident angle is 85 degrees, and the solid line indicates the case where the incident angle is 40 degrees.

FIGS. 1 to 3 show that the difference in the spectral pattern when the foundation is applied is an intermediate type between the difference in the spectral pattern in the case of bare skin and that of the standard skin color plate. Therefore, it can be seen that the closer the difference between the spectral patterns to the difference between the spectral patterns of the bare skin, the more the finished skin feels, and the closer it is to that of the standard skin color plate, the more matte the finish. Therefore, by comparing the obtained spectral spectra of the two reflected lights, it is possible to evaluate the extent to which the makeup looks natural and beautiful.

The method of comparing the spectral patterns at this time is not particularly limited as long as the spectral patterns can be compared qualitatively or quantitatively.
It is convenient and preferable to obtain the AX-RAO value and use it as an index.

That is, in the present invention, visible light having a wavelength range of 400 to 700 nm is radiated onto the surface subjected to make-up from two directions having different incident angles with respect to the surface. The spectra of the two reflected lights are measured, and at each wavelength, [(reflectance of reflected light for irradiation light having a smaller incident angle to the surface) − (reflectance of reflected light for irradiation light having a larger incident angle to the surface) / (Reflectance of reflected light with respect to irradiation light having a larger incident angle with respect to the surface)], which is the maximum value in the measurement wavelength range, and calculates the MAX-RAO value.
The spectral patterns are compared using the O value as an index.

For the comparison of the spectral patterns of the reflected light with respect to the visible light in these two directions, it is appropriate to use the integrated value of the difference in the spectral luminous intensity (spectral reflectance) in the measurement wavelength range. As shown in FIG. 5, there is an excellent linear regression between the -RAO value and -RAO value.
X-RAO values can be used. FIG.
Is an incident angle of 4 for 20 randomly selected panelists.
The difference between the reflectances in the measurement wavelength range of 400 to 700 nm represented by the following formula (II) calculated using the reflectance of the spectral spectrum of each reflected light when the visible light is irradiated at 0 degree and 85 degrees. It is a plot of the integrated value and the MAX-RAO value calculated from the above formula (I) using the same reflectance.

[0027]

(Equation 3)

(In the formula (II), A represents the reflectance of reflected light with respect to visible light at an incident angle of 85 degrees, and B represents the reflectance of reflected light with respect to visible light at an incident angle of 40 degrees.)

Also, the beauty of the skin and M
The relationship with the AX-RAO value is, as shown in FIG.
When the RAO value is 3 to 5, it is determined that there is a beautiful bare skin feeling regardless of race. Here, the beauty of the bare skin is evaluated by five specialized panelists with a score of 5 for "very beautiful" and a score of 0 for "not very beautiful", and the average score is a representative value. When judging the beauty of the bare skin, skin texture, fineness, skin clarity, skin luster, surface smoothness, skin firmness, and lack of color unevenness are mainly used as factors. I have.

Therefore, the makeup cosmetic can be evaluated by measuring the MAX-RAO value and examining whether the value is close to the reference value of beautiful skin. For example, when using beautiful natural skin as a reference, M
When the AX-RAO value is close to the reference value of the bare skin,
It can be evaluated as a cosmetic that can make up with a natural and bare skin feeling. In addition, it can be determined that the cosmetic having a small MAX-RAO value is a cosmetic that can make up a matte finish.

When the incident angles of visible light are 85 degrees and 40 degrees,
MAX-RAO as a beautiful finish with bare skin feeling
Values 4 to 7 can be exemplified. This differs depending on the incident angle. This evaluation method is most suitably applied to the evaluation of foundation, but can be used as a criterion from an unprecedented viewpoint in the evaluation of eye makeup, cheek color and lip color.

In this analysis, more information can be obtained by performing the same analysis on visible light not only in two directions but also in more directions. However, it is difficult to analyze, but the information obtained is relatively small, so analysis with incident light from two directions is practical.
preferable.

The light irradiation in each direction may be performed individually or simultaneously. However, since there are many merits such as simple measurement, easy operation, and easy and short analysis, individual light irradiation is possible. It is preferable to measure the spectrum by irradiating the light. Of course, in the analysis of reflected light, MA
Instead of using the X-RAO value, it is also possible to perform analysis using pattern similarity analysis, integration value analysis, the average value of the square of the difference, or the like as an index, and these also belong to the evaluation method of the present invention. It is preferable to compare using the MAX-RAO value from the viewpoint of simplicity and accuracy.

These spectroscopic analyzes may be performed according to an ordinary method using a commercially available spectrophotometer. The evaluation method of the present invention can be used in combination with other evaluation methods of makeup cosmetics such as a covering power index and a photographic sensitivity test, and in this case, the accuracy of evaluation can be further increased.

[0035]

The present invention will be described in more detail with reference to the following examples, but it goes without saying that the present invention is not limited to these examples.

[0036]

Example 1 Using 10 female panelists arbitrarily selected, foundations of different types of bare skin and two types of finishes, that is, a foundation with a matte feeling (Foundation 1) and a foundation with transparency (Foundation 1) When makeup is performed in step 2), the skin is irradiated with visible light at 85 ° and 40 °, and the reflected light is measured for its spectral spectrum using a spectrophotometer (U-3500 type spectrophotometer, manufactured by Hitachi, Ltd.). [(Reflectance of reflected light with respect to visible light at an incident angle of 40 degrees) of each wavelength] −
(Reflectance of reflected light with respect to visible light at an incident angle of 85 degrees) /
(Reflectance of reflected light with respect to visible light at an incident angle of 85 degrees)], and the maximum value, MAX-RAO value, was calculated.

At the same time, the finish was evaluated by five expert panelists from the viewpoint of transparency and natural finish. The evaluation was 0 points for "Thick like skin-colored tiles" for transparency and 10 points for "Skin-like skin of panelists", and "Skin-like tiles" for natural finish. A score of 0 and a score of "like the skin of the panelist" were given as 10 points.

Finish for each foundation and M of bare skin
FIG. 6 shows changes in the AX-RAO value. The average of the evaluation scores of the transparency was 5.8 for Foundation 1 and 8.4 for Foundation 2. As a natural finish, foundation 1 was 4.9 and foundation 2 was 8.8. From these results, MAX-R
It is clear that a makeup whose AO value approaches the value of a beautiful bare skin has a beautiful finish with a bare skin feeling when viewed by others.

[0039]

Example 2 As in Example 1, one panelist was also evaluated for cheek color. The teak colors used were a matte type teak color 1 and a natural teak color 2. MAX for cheek color 1
-RAO value is 1.8 and M for teak color 2
The AX-RAO value was 3.1. MAX-RA of bare skin
The O value was 2.8. Transparency of cheek color 1 is 4.
9, the cheek color 2 was 7.6, and the natural finish was 5.3 for the cheek color 1 and 8.1 for the cheek color 2. From these results, it is clear that makeup whose MAX-RAO value approaches the value of beautiful bare skin has a beautiful finish with bare skin feeling when viewed by others.

[0040]

According to the present invention, it is possible to clarify the optical theory by which the skin texture appears and the skin looks beautiful, and to provide a method for evaluating a makeup cosmetic which makes the skin look beautiful.

[Brief description of the drawings]

FIG. 1 is a diagram showing a spectral spectrum of reflected light when untreated skin is irradiated with visible light at incident angles of 85 ° and 40 °.

FIG. 2 is a diagram showing a spectral spectrum of reflected light when visible light is irradiated at incidence angles of 85 ° and 40 ° to skin made up with a matte foundation.

FIG. 3 is a diagram showing a spectral spectrum of reflected light when a skin color standard plate is irradiated with visible light at incident angles of 85 ° and 40 °.

FIG. 4 is a diagram illustrating a relationship between beauty of bare skin and a MAX-RAO value.

FIG. 5 is a diagram showing a relationship between an integrated value of a difference between spectrophotometers and a MAX-RAO value.

FIG. 6 is a diagram showing a change in MAX-RAO value when bare skin and two types of foundations are applied.

Claims (8)

[Claims] 1. A method for evaluating make-up cosmetics, comprising irradiating a surface having the make-up cosmetics applied thereto with light having a wavelength range of visible light from at least two directions having different incident angles to the surface. And measuring a spectrum of each of the plurality of reflected lights obtained from the irradiation light, and comparing the spectrum patterns with each other. 2. The method according to claim 1, wherein the irradiation light has an angle of incidence of 1
Visible light of 0 to 60 degrees and an incident angle of 75 to 9 with respect to the surface.
The method of claim 1 including zero degree visible light. 3. The wavelength range of the irradiation light is 400 to 700.
The method according to claim 1, wherein the molecular weight is nm. 4. The method according to claim 1, wherein spectra of the plurality of reflected lights are measured independently of each other. 5. The surface is irradiated with the irradiation light from two directions having different incident angles to the surface.
A method according to any of claims 1 to 4. 6. The method according to claim 1, wherein the irradiation light has an incident angle of 1
Visible light of 0 to 60 degrees and an incident angle of 75 to 9 with respect to the surface.
6. The method according to claim 5, comprising zero degree visible light. 7. In the comparison of the spectral patterns, visible light in a wavelength range of 400 to 700 nm is irradiated on the surface from two directions having different incident angles with respect to the surface, and the spectra of two reflected lights obtained from the irradiated light are obtained. Each was measured, and a MAX-RAO value was calculated from the reflectance of the spectrum of each reflected light in the wavelength range by the following formula (I),
The method according to claim 1, wherein the comparison is performed using an X-RAO value as an index. MAX-RAO = [(BA) / A] _max ... (I) (In the formula (I), A represents the reflectance of the reflected light with respect to the irradiation light having a larger incident angle with respect to the surface.) And B represents the reflectance of reflected light with respect to irradiation light having a smaller incident angle with respect to the surface, and [( _BA ) / A] _max represents the maximum value of ( _BA ) / A in the wavelength range. .) 8. The method according to claim 1, wherein the makeup cosmetic is a foundation.