JP6420174B2 - How to evaluate the natural finish of makeup skin - Google Patents

Description

  The present invention relates to a method for evaluating the natural finish of makeup skin.

Conventionally, the evaluation of the finish of the makeup skin has been left to sensory evaluation by a specialized panel, which cannot be evaluated without a specialized panel, which has been an obstacle to more rapid development of cosmetics.
On the other hand, cosmetics that can obtain natural and healthy makeup skin without dullness using the characteristics of the spectral reflection spectrum have been studied (Patent Document 1, Patent Document 2, and Patent Document 3).

Japanese Patent Laid-Open No. 10-17437 Japanese Patent Laid-Open No. 10-42950 JP 2001-163731 A

However, since the methods described in Patent Documents 1 to 3 are affected by skin color, particularly the spectral reflectance of the skin, it is difficult to quantitatively evaluate the finish of the makeup skin.
Therefore, there is a need for a method that can accurately and quantitatively evaluate the natural finish of makeup skin, regardless of sensory evaluation of a specialized panel or the like.

  The present inventors have found that the natural finish of the makeup skin can be accurately and quantitatively evaluated by measuring the spectral reflection spectrum of the bare skin and the skin after makeup, and determining the reflectance ratio curve.

  The present invention measures the spectral reflection spectrum (Y1) of 420 nm to 700 nm on the bare skin and the spectral reflection spectrum (Y2) of 420 nm to 700 nm on the skin after makeup, and the spectral reflection of (Y2) with respect to (Y1) at each wavelength. The present invention relates to a method for evaluating the natural finish of makeup skin by obtaining a curve of rate ratio (Y2) / (Y1).

  According to the present invention, the natural finish of makeup skin can be quantified, and can be evaluated quickly and accurately. In addition, it is possible to evaluate in detail the feeling of whitening, powderiness, feeling of thick coating, and feeling of unevenness of the finished skin.

400 nm to 700 nm spectral reflectance spectrum (Y1), 400 nm to 700 nm spectral reflectance spectrum (Y2), and spectral reflectance of the skin after makeup were measured for those with a natural finish and an unnatural finish. It is a figure which shows an example of the curve of ratio (Y2) / (Y1) of a ratio. In the examples, when the same powder foundation was applied, the spectral reflection spectrum (Y1) of 420 nm to 700 nm on the bare skin, measured on the natural finish person and the unnatural finish person, 420 nm on the skin after the powder foundation application. It is a figure which shows the curve of -700 nm spectral reflection spectrum (Y2), spectral reflectance ratio (Y2) / (Y1). In the example, in the curve of the spectral reflectance ratio (Y2) / (Y1), with respect to the point of 650 nm, any of the protrusion regions II of 540 nm to 580 nm with the inclination of the protrusion region I of 450 nm to 470 nm as the horizontal axis It is the figure which plotted each measured point on the graph which made the difference with the point the vertical axis | shaft.

In the present invention, first, a spectral reflection spectrum (Y1) of 420 nm to 700 nm on the bare skin and a spectral reflection spectrum (Y2) of 420 nm to 700 nm on the skin after makeup are measured. The spectral reflection spectrum can be measured using a normal spectral colorimeter, for example, CM-2600d (manufactured by Konica Minolta) or the like can be used. It can also be measured using an imaging spectrometer, hyperspectral camera, multispectral camera, or the like.
Examples of the light source used as illumination conditions for the measurement include incandescent light bulbs, external electrode fluorescent tubes, xenon light, halogen light, LEDs (Light Emitting Diodes), and the like. Can be used. The number of lights and the position direction of the lights can be set according to the purpose.
In addition to the skin, artificial skin, resin plates, etc. may be used for measuring the spectral reflection spectrum and evaluating the finish of the makeup skin.

From the measured spectral reflectance spectra (Y1) and (Y2), the curve of the ratio (Y2) / (Y1) of the spectral reflectance spectrum (Y2) of the skin after reflection to the spectral reflectance spectrum (Y1) of the bare skin is obtained. Ask.
For example, as shown in FIG. 1, a curve of spectral reflectance ratio (Y2) / (Y1) is obtained from the spectral reflection spectrum (Y1) of the bare skin and the spectral reflection spectrum (Y2) of the skin after makeup.
For those who have a natural finish, the spectral reflectance spectrum (Y1) of the bare skin and the spectral reflectance spectrum (Y2) of the skin after makeup hardly change, and the curve of the spectral reflectance ratio (Y2) / (Y1) is a straight line (Fig. 1, top).
In contrast, a person with an unnatural finish has a large change in the spectral reflectance spectrum (Y1) of the bare skin and the spectral reflectance spectrum (Y2) of the skin after makeup, and the ratio of spectral reflectance (Y2) / (Y1). This curve is a curve having a protrusion region I of 420 nm to 470 nm and a protrusion region II of 540 nm to 580 nm (FIG. 1, lower stage).

  In the present invention, in the spectral reflectance ratio (Y2) / (Y1) curve, the projection region I of 420 nm to 470 nm is used as an index with the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm as a reference. As a result, the natural finish of the makeup skin can be evaluated. The reference point may be a ratio of spectral reflectance of any wavelength in the region of 640 nm to 660 nm, and if the specific point cannot be determined by a measuring device or the like, the average value in the region of 640 nm to 660 nm It may be.

In the curve of the spectral reflectance ratio (Y2) / (Y1), with reference to the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm, the slope, difference or area of the projection region I of 420 nm to 470 nm Can be used as an index.
Using the protrusion region I of 420 nm to 470 nm as an index, the natural finish of the makeup skin can be evaluated, and above all, the whitening feeling and powderiness of the skin after makeup can be evaluated.
It is preferable to use the slope of the protrusion region I of 420 nm to 470 nm as an index from the viewpoint that the feeling of whitening of the skin after makeup can be accurately evaluated.
In the curve of spectral reflectance ratio (Y2) / (Y1), when the slope of the projection region I of 450 nm to 470 nm is −0.003 or more, the whitening feeling and powderiness of the skin after makeup are observed. It can be evaluated that the makeup skin has a natural finish.

Here, an index of the projection region I is defined.
The protrusion region I indicates a region where the wavelength of the spectral reflectance ratio (Y2) / (Y1) curve is 420 nm to 470 nm and a wavelength of 420 nm in the spectral reflectance ratio (Y2) / (Y1) curve. A portion surrounded by a straight line, a straight line showing a wavelength of 470 nm, and a straight line showing a ratio of spectral reflectances of any wavelength in the region of 640 nm to 660 nm as a reference is shown.
The inclination mentioned here means the inclination of a straight line obtained by connecting two points of the spectral reflectance ratio at a wavelength of 420 nm and the point indicating the spectral reflectance ratio at a wavelength of 470 nm.
Therefore, the calculation formula of the inclination of the protrusion region I of 420 nm to 470 nm is ((spectral reflectance ratio (Y2) / (Y1) 470 nm) − (spectral reflectance ratio (Y2) / (Y1) 420 nm))) / It can obtain | require by calculating with a difference wavelength (470nm-420nm).
The difference is the ratio (Y2) / (Y1) of spectral reflectances at any wavelength in the 640 nm to 660 nm region as a reference and the spectral reflectance at any wavelength in the 420 nm to 470 nm region. It is a value obtained by subtracting the ratio (Y2) / (Y1).
Furthermore, the area of the projection region I refers to the area of the projection region I defined above.
In addition, the wavelength selected in the region where the wavelength of the spectral reflectance ratio (Y2) / (Y1) curve is 420 nm to 470 nm is arbitrary, and can be appropriately selected as long as it is in the range of 420 nm to 470 nm.

  Further, in the present invention, in the curve of the spectral reflectance ratio (Y2) / (Y1), the projection region II of 540 nm to 580 nm with reference to the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm. The natural finish of the makeup skin can be evaluated using as an index. The reference point may be a ratio of spectral reflectance of any wavelength in the region of 640 nm to 660 nm, and if the specific point cannot be determined by a measuring device or the like, the average value in the region of 640 nm to 660 nm It may be.

In the curve of the spectral reflectance ratio (Y2) / (Y1), the difference or area of the protrusion region II of 540 nm to 580 nm is used as an index with the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm as a reference It can be.
Using the projection region II of 540 nm to 580 nm as an index, the natural finish of the makeup skin can be evaluated, and above all, the feeling of thick coating and unevenness of the skin after makeup can be evaluated.
It is preferable to use the difference between any point in the region of 640 nm to 660 nm and any point in the projection region II of 540 nm to 580 nm as an index from the viewpoint that the feeling of thick coating of the skin after makeup can be accurately evaluated.
Especially, it is preferable to obtain the difference between the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm and 550 nm, and the difference is, for example, the spectral reflectance ratio (Y2) / (Y1) of 650 nm. ) As a reference, the difference from the spectral reflectance ratio (Y2) / (Y1) of 550 nm can be obtained.
In the curve of the spectral reflectance ratio (Y2) / (Y1), the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm and the spectral of any wavelength of the projection region II of 540 nm to 580 nm. When the difference from the reflectance ratio is 0.10 or less, and further 0.06 or less, it is evaluated that the makeup skin has a natural finish without the feeling of thick coating or unevenness of the skin after makeup. be able to.

Here, an index of the projection region II is defined.
The protrusion region II indicates a region where the wavelength of the spectral reflectance ratio (Y2) / (Y1) curve is 540 nm to 580 nm and a wavelength of 540 nm in the spectral reflectance ratio (Y2) / (Y1) curve. A part surrounded by a straight line, a straight line showing a wavelength of 580 nm, and a straight line showing a ratio of spectral reflectances of any wavelength in the region of 640 nm to 660 nm as a reference is shown.
The difference here is the ratio (Y2) / (Y1) of the spectral reflectance of any wavelength in the 640 nm to 660 nm region as a reference and the spectral reflection of any wavelength in the 540 nm to 580 nm region. It means a value obtained by subtracting the ratio of ratios (Y2) / (Y1).
Further, the area of the protrusion region II refers to the area of the protrusion region II defined above.
In addition, the wavelength selected in the region where the wavelength of the spectral reflectance ratio (Y2) / (Y1) curve is in the range of 540 nm to 580 nm is arbitrary, and can be appropriately selected in the range of 540 nm to 580 nm.

Furthermore, in the present invention, in the curve of the spectral reflectance ratio (Y2) / (Y1), the projection region I of 450 nm to 470 nm with reference to the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm. The natural finish of the skin can be evaluated from the plotted graph including the coordinate axis indicating the difference between the coordinate axis indicating the inclination of the curve and the point of any one of the protrusion regions II of 540 nm to 580 nm.
For example, each of the measured values in a graph in which the slope of the projection region I of 450 nm to 470 nm is plotted on the horizontal axis, and any point of the projection region II of 540 nm to 580 nm, preferably the difference between 550 nm and the reference point is plotted on the vertical axis. When plotting points, the slope of the projection region I of 450 nm to 470 nm is large (close to 0), and the smaller the difference from any point of the projection region II of 540 nm to 580 nm, the more natural the makeup skin is. Can be evaluated.

Example 1
Targeted individuals who do not have any unnaturalness in the finish of their makeup skin and those who do not have any unnatural problems, the professional beauty staff applied the same amount of powder foundation with the composition shown in Table 1 to each subject's skin using a sponge. Later, it was evaluated whether the specialized panel had a “natural finish” or “unnatural finish”.
On the other hand, for each subject, a spectral reflection spectrum (Y1) of 420 nm to 700 nm on the bare skin and a spectral reflection spectrum (Y2) of 420 nm to 700 nm on the skin after applying the powder foundation were measured. The measurement apparatus used an imaging spectrometer V8E (manufactured by JFE Techno-Research Corporation), and irradiated the xenon diffused light (7000 lxs) as a light source from the front upper side of the subject to measure the spectral reflectance of the skin.
In addition, the powder foundation of the composition shown in Table 1 was manufactured by the following method.

(Production method)
After mixing and pulverizing all the powder components, the oil phase component was added and mixed, and the resulting mixture was further pulverized by a pulverizer. The pulverized product obtained here was filled in a container and molded with a filling amount of 10.0 g and a molding pressure of 1500 kg to obtain a powder foundation.

From the measured spectral reflectance spectrum, for each subject, the ratio of the spectral reflectance of the spectral reflectance spectrum (Y2) of 420 nm to 700 nm on the skin after powder foundation application to the spectral reflectance spectrum (Y1) of 420 nm to 700 nm on the bare skin. A curve of (Y2) / (Y1) was obtained.
Spectral reflection spectra (Y1), (Y2) and spectral reflectance ratio (Y2) / (Y1) curves for each example of a natural finish person and an unnatural finish person evaluated by a professional panel As shown in FIG.

From the results of FIG. 2, there are people who can get a natural finish even when the same powder foundation is applied, and people who get an unnatural finish, and the curve of spectral reflectance ratio (Y2) / (Y1) A big difference was recognized.
A person who has obtained a natural finish has a value of -0.0027 in the slope of the projection region I of 450 nm to 470 nm on the basis of the point of 650 nm in the curve of the spectral reflectance ratio (Y2) / (Y1). Was close to 0, and there was no whitening or powderiness on the skin after makeup. In addition, the difference from the 550 nm protrusion region II with respect to the 650 nm point is as small as 0.04, and there is no feeling of thick coating or unevenness of the skin after makeup, and a natural finish is obtained. It was.
In contrast, a person who has an unnatural finish with noticeable whitening and powderiness after makeup uses a point of 650 nm in the spectral reflectance ratio (Y2) / (Y1) curve as a reference. If the inclination of the protrusion region I of 450 nm to 470 nm is negative as negative as −0.006 and the thick feeling and unevenness of the skin after makeup is conspicuous, the protrusion region II of 550 nm is based on the point of 650 nm. And the difference is as large as 0.15.

Example 2
In the curve of the spectral reflectance ratio (Y2) / (Y1) of each subject obtained in Example 1, with reference to the point of 650 nm, the slope of the projection region I of 450 nm to 470 nm and the point of 650 nm As a result, the difference from the projection region II of 550 nm was obtained.
The obtained results were plotted in a graph in which the slope of the projection region I of 450 nm to 470 nm was plotted on the horizontal axis and the difference from the projection region II of 550 nm was plotted on the vertical axis (FIG. 3).
The plot of the 12 persons who were evaluated as “natural finish” by the expert panel shows that the slope of the projection region I of 450 nm to 470 nm is close to 0 and the difference from the projection region II of 550 nm on the basis of the point of 650 nm A small tendency was also observed. On the other hand, the plot of the 17 persons who were evaluated on the specialized panel as “the whitening feeling and powderiness of the skin after makeup was conspicuous and unnatural finish” shows that the slope of the projection region I of 450 nm to 470 nm is The plot of a person who was negatively large and was evaluated on the professional panel as “uneven finish with a noticeable thick and uneven skin feel after makeup” is a 550 nm protrusion area based on a 650 nm point. There was also a tendency for large differences from II.

Claims (8)

  The spectral reflectance spectrum (Y1) of 420 nm to 700 nm on the bare skin and the spectral reflectance spectrum (Y2) of 420 nm to 700 nm on the skin after makeup are measured, and the ratio of the spectral reflectance of (Y2) to (Y1) at each wavelength ( Y2) A method for evaluating the natural finish of makeup skin by obtaining a curve of (Y1).   In the curve of the spectral reflectance ratio (Y2) / (Y1), evaluation is performed using the projected region I of 420 nm to 470 nm as an index with the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm as a reference. The method for evaluating the natural finish of the cosmetic skin according to claim 1.   The method for evaluating the natural finish of a cosmetic skin according to claim 2, wherein, in the curve of the spectral reflectance ratio (Y2) / (Y1), the index of the protrusion region I of 420 nm to 470 nm is an inclination, a difference or an area. .   4. The natural finish is evaluated when the slope of the projection region I of 450 nm to 470 nm is −0.003 or more in the curve of the spectral reflectance ratio (Y2) / (Y1). To evaluate the natural finish of your skin.   In the curve of spectral reflectance ratio (Y2) / (Y1), evaluation is performed using the projected region II of 540 nm to 580 nm as an index with the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm as a reference. The method for evaluating the natural finish of the cosmetic skin according to claim 1.   The method for evaluating the natural finish of a makeup skin according to claim 5, wherein the index of the projection region II of 540 nm to 580 nm is a difference or an area in the curve of the spectral reflectance ratio (Y2) / (Y1).   In the curve of the spectral reflectance ratio (Y2) / (Y1), when the difference from any point of the projection region II of 540 nm to 580 nm is 0.10 or less, the natural finish is evaluated. Item 7. A method for evaluating the natural finish of makeup skin according to Item 5 or 6.   In the curve of the spectral reflectance ratio (Y2) / (Y1), with reference to the spectral reflectance ratio of any wavelength in the region of 640 nm to 660 nm, the coordinate axis indicating the inclination of the projection region I from 450 nm to 470 nm; A method for evaluating the natural finish of the skin from a plotted graph including a coordinate axis indicating a difference from any point of the projection region II of 540 nm to 580 nm.