JP2022111309A - Method and device for evaluating texture of cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for accurately and quantitatively evaluating the texture of a cosmetic.

SOLUTION: The method for evaluating the texture of a cosmetic includes: a vibration detection step of detecting a vibration over time generated by moving an action body while bringing the action body into contact with a cosmetic applied on an application surface; a data generation step of generating data on the change over time of a frequency spectrum of the vibration from the detected vibration; and an evaluation step of evaluating the texture of the cosmetic by using the generated data.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a method for evaluating the feel of use of cosmetics and an apparatus for evaluating the feel of use of cosmetics.

Conventionally, it is difficult to objectively evaluate the feeling of use of cosmetics such as stickiness, moistness, and freshness. Therefore, it has been studied to quantify the feeling of use of cosmetics based on the physical properties inherent to the cosmetics.

For example, Patent Literature 1 discloses a method of evaluation based on rheological properties. Further, Patent Document 2 discloses a method of evaluating physical properties obtained from shear force measurement as an index.

Japanese Patent No. 5749554 JP 2016-180685 A

However, the evaluation index of cosmetics in the conventional methods disclosed in Patent Documents 1 and 2 is bulk physical properties of cosmetics. In other words, it is a property measured in a state different from the actual use state of the cosmetic. Therefore, the conventional method may not be able to accurately evaluate the feel in use.

In view of the above points, an object of one embodiment of the present invention is to provide a method for more accurately and quantitatively evaluating the feeling of use of cosmetics.

One aspect of the present invention for solving the above problems is a vibration detection step of detecting over time vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated. , a data generation step of generating data relating to temporal changes in the frequency spectrum of the vibration from the detected vibration; and an evaluation step of evaluating the feel of use of the cosmetic using the generated data. It is a method for evaluating the feel of use of cosmetics.

ADVANTAGE OF THE INVENTION According to one form of this invention, the method of evaluating the feel of use of cosmetics more correctly quantitatively can be provided.

1 is a flow diagram illustrating a method according to one aspect of the invention; FIG. 1 is a schematic diagram of an apparatus according to one aspect of the invention; FIG. 4 is a schematic enlarged view of vibration generating means and vibration detecting means; FIG. FIG. 4 is a flow chart showing a specific example of a data generation step; FIG. 4 is a diagram schematically showing an example of a spectrum distribution diagram showing temporal changes in frequency spectrum; FIG. 4 is a diagram for explaining data generation based on a spectrum distribution diagram showing temporal changes in frequency spectrum; 4 is a diagram showing a correlation between an evaluation value S _estimated by a regression equation and an evaluation value S0 by sensory evaluation in Example 1. FIG. FIG. 10 is a diagram showing the correlation between an evaluation value S estimated by a regression equation and an evaluation value S0 by sensory evaluation in Example ₂ ; 10 is a diagram showing the correlation between the evaluation value S _estimated by the regression equation and the evaluation value S0 by sensory evaluation in Example 3. FIG. FIG. 10 is a diagram showing the results of time-series sensory evaluation in Example 4; FIG. 11 is a graph of the feel in use evaluated in Example 4, extracted from FIG. 10. FIG. FIG. 10 is a diagram showing a correlation between a predetermined statistic value and a representative value of sensory evaluation of “thickness” in the latter period in Example 4; FIG. 11 is a graph of the feeling in use evaluated in Example 5, extracted from the graph of FIG. 10. FIG. FIG. 10 is a diagram showing the correlation between the predetermined statistic value and the representative value of sensory evaluation of “stickiness” in the previous term in Example 5;

Modes for carrying out the present invention will be described below, but the present invention is not limited to the following embodiments.

<Method for evaluating texture in use>
The present inventors applied cosmetics to a surface to be coated, and moved the operating body while the operating body was in contact with the applied cosmetic. It was found that there is a correlation between the sensory evaluation of the feeling of use of the ingredients.

One embodiment of the invention based on this finding is, as shown in FIG. 1, to detect over time vibrations generated by moving the operating body while the operating body is in contact with the cosmetic applied to the surface to be coated. A vibration detection step (S1), a data generation step (S2) of generating data on changes over time in the frequency spectrum of the vibration from the detected vibration, and using the generated data, the feeling of use of the cosmetic is estimated. and an evaluation step (S3) for evaluation.

This embodiment utilizes data related to vibrations generated by rubbing or stroking the cosmetic applied to the surface to be coated as an index for evaluating the feel of use. In other words, as an evaluation index, attention is paid to vibration, which is considered to be closely related to tactile sensation, rather than bulk properties of cosmetics. Furthermore, the present embodiment uses data measured in a state close to the state in which cosmetics are actually used. Therefore, it is possible to more accurately evaluate the feeling of use of the cosmetic.

In addition, sensory evaluation by a panel is often used as a method for evaluating the feeling of use of cosmetics, but the evaluation may vary. By using the evaluation method according to the present embodiment instead of such a sensory evaluation, it is possible to more accurately evaluate the feel in use.

In this embodiment, the data used as the evaluation index specifically relates to changes over time (time-series changes) in the frequency spectrum of vibration. When a cosmetic is applied to the skin, it usually permeates into the skin or part of its ingredients volatilize into the air, and the physical properties of the cosmetic change over time. The timing and degree of such change over time differ depending on the cosmetic, and the difference in this change over time between cosmetics appears as a difference in the feel of use of the cosmetic. Furthermore, such a difference in feel during use is reflected in a difference in temporal change in the content of frequency components in the vibration detected when the cosmetic material applied to the application surface is rubbed. Therefore, in the present embodiment, by using the data on the temporal change of the frequency spectrum as an index, it is possible to more accurately grasp even the slight difference in feel in use that differs depending on the cosmetic.

In the present specification, the feeling of use of a cosmetic (also referred to as a feeling of use or texture) refers to the feeling that a person feels when the cosmetic is applied to the skin such as the face or body, or after a predetermined time has passed since the application of the cosmetic. It's a feeling you feel. Therefore, the feel in use to be evaluated by the method according to the present embodiment can include the feel felt when the cosmetic comes into contact with the skin for the first time and spreads it on the skin. , the sensation felt by the skin, or the sensation felt by the fingers, the palm, etc. when the skin is stroked or rubbed with the fingers, the palm, etc., can also be included.

Specific examples of the texture to be evaluated include stickiness, freshness, moistness, penetration, moisture, tightness, firmness, smoothness, mellowness, thickening, light (or heavy) spreadability, freshness, Oily, sticky feeling, etc. can be mentioned.

Cosmetics may include cosmetics provided as final products (cosmetics), cosmetic bases, compounds blended to constitute cosmetic bases, and mixtures thereof.

As described above, there is a correlation between the data on changes in the frequency spectrum of vibration over time and the sensory evaluation. Any temporal sensory evaluation that assesses temporal transition (change over time) is included. In the evaluation without consideration of the time axis, the subject performs the evaluation after a predetermined time has passed from the start of application of the cosmetic. Ultimately, depending on the case, some one evaluation value (score or the like) can be obtained for one evaluation item for a predetermined cosmetic through data processing or the like. This sensory evaluation that does not consider the time axis can be said to be a comprehensive evaluation of the feeling of use that can be felt when cosmetics are applied to the skin. The end of the application may refer to the point in time when the general amount of the cosmetic has been applied, or may refer to the point in time when the cosmetic is felt to be familiar to the skin to some extent. A specific evaluation method that does not consider the time axis is not particularly limited, and may be a method called VAS (Visual Analog Scale), SD method (Semantic Differential Method), QDA (Quantitative Description Analysis), or the like.

On the other hand, in the time-series sensory evaluation, the subject performs evaluation at two or more timings during the period from the start of application of the cosmetic to the elapse of a predetermined time. Then, in some cases, the obtained evaluation data can be processed to obtain the temporal transition of the evaluation value for one evaluation item for a predetermined cosmetic. The temporal transition of the evaluation value can be represented by, for example, a graph with time on the horizontal axis and magnitude of the evaluation value on the vertical axis. In this case, the subject may perform evaluation focusing on one evaluation item, or may evaluate a plurality of evaluation items in one test. The time-series sensory evaluation is an evaluation method that can more accurately capture the characteristics of cosmetics whose texture tends to change over time. Time series sensory evaluation includes, for example, TDS (Temporal Dominance of Sensations), TCATA (Temporal Check All That Apply), TI (Time Intensity), and the like. In the case of sensory evaluation by TDS, the evaluation value of the time-series sensory evaluation may be represented by a dominance rate or the like in a unit such as a percentage.

In sensory evaluations such as those described above, especially in time-series sensory evaluations, when trying to improve the accuracy of the evaluation, it becomes necessary to select excellent specialized panels or collect a large amount of data, which is time-consuming and costly. It may take On the other hand, according to the evaluation method according to the present embodiment, such labor and cost can be suppressed.

<Vibration Detection Step (S1)>
In the vibration detection step (S1), vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated are detected over time.

(Occurrence of vibration)
The vibration detection step (S1) may include generating vibrations to be detected. Vibration can be generated using, for example, vibration generating means 10 as shown in FIGS. In the illustrated vibration generating means 10, a predetermined amount of cosmetic is applied to the skin on the inner side of a person's forearm, and vibration is generated by rubbing the applied cosmetic with the tip of a person's finger, for example, the tip of the index finger. Let In other words, the application surface 11 is the skin on the inside of a person's forearm, and the action body 12 is the index finger. generate vibration. In this specification, the application of a cosmetic refers to spreading a predetermined amount of the cosmetic by dropping it onto a predetermined surface. The means of application is not particularly limited as long as a film of the cosmetic can be formed on the surface. It's okay.

The surface 11 to be coated may be the surface of human skin as shown in FIG. It may be the surface. The coated surface 11 may be flat or uneven. The surface 11 to be coated is not limited to the skin of a living person, and may be processed or unprocessed animal skin, artificial You may use synthetically manufactured leather or pseudo-skin. However, if the surface to be coated 11 is the surface of human skin, vibrations can be generated in a state closer to the actual usage conditions, which is preferable.

The action body is a subject that moves relative to the surface to be coated while being in contact with the cosmetic applied to the surface to be coated. In the example of FIG. 2, the index finger is used as the action body 12, but the action body 12 may be another finger such as the middle finger, or may be the palm, arm, or other part of the human body. . Further, like the coated surface 11, the working body 12 may be made of a material having properties equivalent or similar to those of living human skin, or may be a member coated with such a material.

However, when the coated surface 11 and the action body 12 are each a part of the human body as in the illustrated embodiment, vibration can be generated in a state close to the state in which the cosmetic is actually used. Therefore, a more accurate evaluation of the feeling of use can be performed. In the human body, the surface of the hand (palm side) has a well-developed tactile perception function, and the inner surface of the fingertip (the side without nails) is often used to identify the feel of use. More accurate data can be acquired when the inner surface of the fingertip is used to rub the cosmetics.

Vibration can be generated by moving the action body 12 while it is in contact with the cosmetic applied to the coated surface 11, and the action of the action body 12 at that time can generate detectable vibration. There is no particular limitation as long as it is an action that can be performed. The operating body 12 may be reciprocated with respect to the surface 11 to be coated, or may be rotated a plurality of times in one direction. Alternatively, the coating surface 11 may be moved so as to draw an arbitrary figure such as a circle or an ellipse.

(Vibration detection)
In the vibration detection step (S1), vibration is generated by rubbing the cosmetic material applied to the application surface, and this vibration may be vibration transmitted to the application surface and/or the action body. , vibration (sound) propagated from the surface to be coated and/or the surface of the operating body through the surrounding medium (air). However, when detecting the vibration transmitted to the coated surface and/or the action body, it is possible to detect the signal at a place near the vibration generation point, and the vibration generated due to other than rubbing the cosmetic is possible. can be reduced. Therefore, it is preferable to detect the vibration transmitted to the surface to be coated and/or the operating body from the viewpoint of improving detection accuracy.

The detection means 20 used in the vibration detection step (S1) can be attached to the action body 12 (a finger in the illustrated example) as shown in FIGS. 2, it can also be attached to the surface 11 to be coated. Alternatively, the detecting means 20 can be attached to both the coated surface 11 and the moving body 12 .

Vibration detection means 20 is not particularly limited as long as it can detect a signal capable of generating data capable of grasping temporal changes in the frequency spectrum (spectrum indicating the distribution of frequency components contained in vibration). , or the acceleration may be detected as an electric signal. As the detection means 20, for example, a triaxial acceleration sensor can be used.

In addition, one type or two or more types of cosmetics may be applied to the surface to be coated. After the first cosmetic is applied to the surface to be coated, vibration is generated as described above, and the vibration is detected, the second cosmetic is applied immediately after that or after a predetermined time has elapsed, Vibrations can be generated and detected as described above. Further, after applying the first cosmetic material, the vibration is not generated and detected, and immediately after or after a predetermined time has elapsed, the second cosmetic material is applied, the vibration is generated as described above, and the vibration is generated. Vibration may be detected.

In this case, the first cosmetic and the second cosmetic may be the same or different. When the first cosmetic and the second cosmetic are the same, the tactile sensation when the same cosmetic is repeatedly applied can be evaluated. In addition, when the first cosmetic and the second cosmetic are different, for example, when the first cosmetic is a lotion and the second cosmetic is a milky lotion, etc., the different cosmetics are applied. It is possible to evaluate the tactile sensation when the cosmetics are piled up, and to evaluate the effect of using a plurality of types of cosmetics together.

<Data generation step (S2)>
In the data generation step (S2), the vibration signal detected in the vibration detection step (S1) is analyzed to generate data relating to temporal changes in the frequency spectrum of the vibration. Here, the data may be data of a diagram or graph such as a spectral diagram, or data of a value or a group of values. Further, analysis of the vibration signal can be performed, for example, by short-time Fourier transform. Through such analysis, it is possible to grasp temporal changes in vibrations containing a plurality of frequency components.

(Spectrum diagram)
According to the above analysis, for one cosmetic, the horizontal axis is the frequency (unit: Hz), and the magnitude of the vibration of the frequency component, for example, the power spectral density (power value per 1 Hz width, unit: dB/ Hz, etc.) can be generated for each of a plurality of predetermined elapsed times after application of the cosmetic material. Further, as schematically shown in FIG. 5, for one cosmetic, a spectrum diagram can be generated in which the horizontal axis is the time and the vertical axis is the frequency, and the positions where the power spectral densities are equal are displayed. When the latter spectral diagram is generated as data, it is possible to display temporal changes in the content ratio of frequency components in vibration for one cosmetic in one spectral diagram, which is preferable.

The latter spectral diagram may be one in which values relating to the magnitude of vibration, for example, the magnitude of the power spectral density, are color-coded, and the power spectral density distribution is displayed by color gradation. Alternatively, it may be a spectral diagram in which points having the same power spectral density are connected to form a line, as schematically shown in FIG.

Although there is no particular limitation on the magnitude of the frequency of the vibration to be analyzed, according to one aspect of the present invention, the frequency range of the vibration is 0 to several MHz, 0 to several tens of kHz, 0 to several kHz, 0 ˜1000 Hz, 0-500 Hz. By setting the frequency range of the vibration to be analyzed to the above range, it is possible to more accurately evaluate the feeling of use of the cosmetic.

The period of time during which the vibration is detected immediately after the cosmetic is applied to the surface to be coated is not particularly limited. For example, vibration can be detected within 150 seconds, within 120 seconds, within 90 seconds, within 60 seconds, or within 30 seconds immediately after application of the cosmetic to the coated surface. By setting the detection time within the above range, it is possible to detect fluctuations in vibration that accompany changes in the composition of the cosmetic due to volatilization of some components or permeation into the coated surface.

When the human skin is the surface to be coated and the human finger is the moving body, it is preferable to detect the signal for about 60 seconds. Vibration detection may be performed continuously over the above time period, or may be performed intermittently. Further, detection of vibration may be started not immediately after application of the cosmetic to the surface to be applied, but after a certain period of time has elapsed after the application. For example, the cosmetic may be applied to the surface to be applied, left for 60 seconds, and after 60 seconds have passed, detection may be started for another 60 seconds.

(values related to the magnitude of vibration)
In the present embodiment, the data on the temporal change in the frequency spectrum of vibration may be the above spectrum diagram itself, and the use tactile sensation of the cosmetic can be evaluated based on this spectrum diagram. However, the data on changes over time in the frequency spectrum of vibration are not diagrams such as spectrum diagrams, but are related to the magnitude or amplitude of vibration corresponding to a predetermined elapsed time and predetermined frequency after the application of cosmetics. may contain data. Such data can be obtained based on generating a frequency spectrum map of the vibrations, or can be obtained directly from the detected vibrations without generating a spectrum map.

The data on the magnitude of vibration corresponding to the predetermined elapsed time and the predetermined frequency after the application of the cosmetic are values regarding the magnitude of the vibration corresponding to the predetermined elapsed time and the predetermined frequency after the application of the cosmetic. There may be one value or a plurality of values regarding the magnitude of vibration corresponding to the predetermined elapsed time after application of the cosmetic and the predetermined frequency. A value related to the magnitude of such vibration can be obtained, for example, by a method shown in the flowchart of FIG.

The flow in FIG. 4 is included in the data generation step (S2) in FIG. In the example of FIG. 4, for values related to the magnitude of vibration, a distribution map showing temporal changes in the frequency spectrum is generated from the vibration (S2a), the distribution map is divided into a plurality of regions (S2b), and each region can be obtained by calculating (S2c) a statistic about the power spectral density at .

More specifically, a distribution map as shown in FIG. 5, that is, a spectrum map showing positions where the horizontal axis is time, the vertical axis is frequency, and the magnitude of vibration (for example, power spectral density) is equal is generated. Then, the spectral diagram is divided into a plurality of regions in a grid pattern, a statistic about the power spectral density in at least one of the plurality of regions is obtained, and the statistic is used as a value related to the magnitude of vibration. can do. In other words, the data on the temporal change in the frequency spectrum obtained in the above data generation step (S2) includes statistics on the power spectral density in a predetermined elapsed time band and a predetermined frequency band after the application of the cosmetic. be able to.

FIG. 6 shows an example of division of the spectrum diagram as shown in FIG. In the example of FIG. 6, the frequency displayed on the vertical axis and the elapsed time displayed on the horizontal axis are each divided into four, and a total of 16 areas Z1 to Z16 are formed as a whole. Then, the statistics v ₁ to v ₁₆ of the power spectral density can be calculated for each of the divided regions Z1 to Z16.

The above statistics are, for example, the arithmetic mean value, geometric mean value (geometric mean value), median value, maximum value, and total value of the power spectral density in a predetermined elapsed time band and a predetermined frequency band after application of the cosmetic. and preferably at least one of an arithmetic mean, a geometric mean and a median. Powers of these statistics and products of different statistics can also be used as statistics for the power spectral density in a predetermined elapsed time band and a predetermined frequency band after application of the cosmetic.

In addition, the statistics are obtained, for example, in the frequency analysis of the detected vibration, obtaining a two-dimensional numerical matrix corresponding to the frequency component and the elapsed time, and using the numerical matrix in a predetermined frequency band and a predetermined time band can be obtained by calculating the amount corresponding to

Also, the statistic may be an integrated value (area integral value) or a centroid value of the power spectrum density in a predetermined elapsed time band and a predetermined frequency band after application of the cosmetic.

In the illustrated example, the spectral diagram is divided so as to form a total of 16 regions, but the number and locations of the regions obtained by dividing the spectral diagram depend on the properties of the cosmetic to be measured, It is determined according to the feel of use to be evaluated. Specifically, in the establishment of the evaluation criteria described later, when spectral diagrams are generated for a plurality of cosmetics and compared with each other, the difference can be determined according to which region is different.

In addition, the spectrum diagram can be divided so that one region has a frequency range (frequency width) of 10 to 500 Hz, preferably 50 to 250 Hz, and one region has a time range (time width) of 5. 60 seconds, preferably 10-20 seconds, but the width of the frequency and time divisions is not limited to the above. The frequency division in the spectrum diagram does not necessarily have to be the same width, and can be appropriately set according to the feeling of use to be evaluated, the properties of the cosmetic, and the like. The same applies to division of time.

In the above embodiment, at least one of the statistics of the power spectrum density in the predetermined elapsed time band and the predetermined frequency band in the spectrum diagram is a value regarding the magnitude of vibration. However, a plurality of magnitudes of vibration corresponding to one point in a predetermined elapsed time and a predetermined frequency in the spectrum diagram, that is, a predetermined elapsed time band and a predetermined frequency band are obtained, and they are related to the above-mentioned vibration magnitude. It can also be a value.

Further, in the above-described embodiment, a spectral diagram is generated and the statistic of the power spectral density is calculated based on the spectral diagram, but the generation of the spectral diagram is not necessarily required for the calculation of the statistic. Based on the detected vibration analysis, statistics can also be determined without generating a diagram.

<Evaluation step (S3)>
In the evaluation step (S3), using the data (spectrum diagram, value, etc.) generated in the data generation step (S2), the feel of use of the cosmetic is evaluated. In the evaluation, it is preferable to establish evaluation criteria in advance and perform evaluation based on the criteria.

(Construction of evaluation criteria (relationship between data and sensory evaluation))
As an evaluation criterion, a relation between data on changes in the frequency spectrum of vibration over time and a sensory evaluation of the feeling of application of cosmetics is constructed and stored in advance. Specifically, for each of a plurality of cosmetics, data on changes in the frequency spectrum of vibration over time was obtained, and on the other hand, sensory evaluation was performed on the feeling of use of each cosmetic. Relationships can be databased. Then, when evaluating the feeling of use of an unknown cosmetic, data on changes over time in the frequency spectrum of vibrations detected by the same method for the unknown cosmetic and the previously constructed relationship (database ), it is possible to estimate the extent of the sensory evaluation value of the feel of use of the unknown cosmetic.

The sensory evaluation performed to construct the evaluation criteria may be an evaluation that does not consider the time axis, or may be a time-series sensory evaluation. In other words, in both the evaluation without consideration of the time axis and the sensory evaluation in chronological order, if a database is constructed for a given cosmetic material, it is It is possible to estimate the sensory evaluation of the cosmetic or the temporal transition of the sensory evaluation.

The method of acquiring data on changes over time in the frequency spectrum of vibration for a plurality of cosmetics is as described above in the vibration detection step (S1) and the data generation step (S2).

In order to obtain the evaluation criteria, a spectral diagram (distribution diagram) is prepared for a plurality of cosmetics, with time on the horizontal axis and frequency on the vertical axis, showing positions where the power spectral densities are equal. (sensory evaluation value) can be associated with. Alternatively, a value relating to the magnitude of vibration may be determined directly from the data of the detected vibration or from the obtained spectrum diagram, and the relationship between the value and the sensory evaluation value may be determined. When the relationship between the value related to the magnitude of vibration and the sensory evaluation is used as the evaluation criterion, the relationship can be represented as an equation and the equation can be used as a model, which facilitates the evaluation.

The relationship (evaluation criteria) between the value relating to the magnitude of vibration and the sensory evaluation can be constructed, for example, as follows.

For a plurality of known cosmetics, a spectral diagram (distribution diagram) is created showing positions with equal power spectral densities with the horizontal axis as time and the vertical axis as frequency, and the spectral diagram is divided into a plurality of regions, A value relating to the magnitude of vibration corresponding to each region is calculated. The division of the region and the calculation of the value are performed in the same manner as the calculation of the value relating to the magnitude of vibration in the data generation step (S2) described above. That is, the value related to the magnitude of vibration corresponding to the predetermined elapsed time and predetermined frequency after the application of the cosmetic is the power in the predetermined elapsed time band and the predetermined frequency band after the application of the cosmetic, as described above. A statistic on the spectral density is preferred. For example, for each of a plurality of known cosmetics, statistics v ₁ to v ₁₆ regarding the power spectral density can be calculated for each of the regions Z1 to Z16 shown in FIG. The statistic may be at least one of an average value, such as an arithmetic mean value, a geometric mean value, a median value, a maximum value, a sum, and an integral value. Also, a plurality of these statistics can be employed for one feeling of use.

In addition, the number of cosmetics used for establishing evaluation criteria can be about 10 to 50, preferably about 20 to 40.

On the other hand, for each of the plurality of known cosmetics described above, sensory evaluation is performed on one or more textures in use (evaluation items). The sensory evaluation may be a sensory evaluation that does not consider the time axis as described above, or may be a time series sensory evaluation.

A sensory evaluation that does not consider a time axis can be, for example, an evaluation by a trained expert panel using a seven-grade score. In the sensory evaluation, a predetermined amount of the cosmetic is placed on the fingertip, and the tactile sensation felt when it is applied to the skin of the face is evaluated. The feeling of use is, for example, stickiness, freshness, moistness, penetration, moisture, tightness, stickiness, smoothness, mellowness, thickness, light (or heavy) spreadability, freshness, oiliness, stickiness, etc. is.

The sensory evaluation by the above-mentioned specialized panel can be an evaluation of the texture felt when the cosmetic is first brought into contact with the skin and applied with fingers, or it can be evaluated after a predetermined time has passed since the application of the cosmetic. It is also possible to evaluate the feel of use when touching the skin with a finger again. The sensory evaluation value by this panel is preferably the arithmetic mean value of the evaluations by 2 to 10 people, more preferably the arithmetic mean value of the evaluations by 5 to 10 people. Note that the method of assigning scores (the number of evaluation stages, etc.) in the sensory evaluation is not particularly limited.

For the construction of the model formula, for example, using the above statistics v ₁ to v ₁₆ obtained for one predetermined use feeling and the sensory evaluation score by a specialized panel, regression analysis is performed, and the value of the statistics and Determine the relationship with the sensory evaluation score. In the model formula, the dependent variable (objective variable) may include the sensory evaluation score of the predetermined feel in use, and the independent variable (explanatory variable) may include at least one of the statistics v ₁ to v ₁₆ . Also, the dependent variable may be the sensory evaluation score of the predetermined feel in use, and the independent variable may include at least one of the statistics v ₁ to v ₁₆ .

In the regression analysis, as an independent variable, the value related to the magnitude of vibration in a predetermined elapsed time after application of the cosmetic and a predetermined frequency band are used as described above, but other parameters are also added. can be used for For example, the independent variables can additionally include frictional values of the cosmetic (values representing frictional properties) and bulk physical properties of the cosmetic.

The value related to the friction of the cosmetic can be, for example, a value based on the frictional force (in units of N) generated by moving the operating body while it is in contact with the cosmetic applied to the surface to be coated. . For example, the frictional force can be measured over time, and the average value, variance, standard deviation, etc. of the magnitude of the frictional force in a predetermined time band can be obtained. In addition, the mean value, variance, standard deviation, and difference between dynamic and static friction coefficients can also be used as independent variables.

The frictional force can be generated, for example, by the same method as that for generating vibration, and the conditions at that time may be the same as or different from those for generating vibration. Further, the frictional force can be measured at the same time as the vibration is detected when the vibration is generated, or can be measured at a timing different from the generation and detection of the vibration.

Bulk physical property values of cosmetics include, for example, viscosity of cosmetics, first normal stress difference, wettability, hardness, and dynamic viscoelasticity. As physical property values of cosmetics, it is preferable to use physical property values representing rheological properties.

In the case where the action body can be deformed when the action body is moved while being in contact with the cosmetic material applied to the coated surface, for example, when the action body is a finger or the like, the deformation amount of the action body is also used as an independent variable. can be used. The amount of deformation is the amount of deformation of the moving body in the direction perpendicular to the surface to be coated, the amount of deformation of the moving body in the direction parallel to the surface to be coated, or the change in the ratio thereof over time, such as the average value, variance, standard deviation, etc. in a predetermined time band. can do. Specifically, the amount of deformation can be the change over time of the thickness of the action body, the area of contact with the surface to be coated, the area when viewed from above or from the side, and the like. The amount of deformation of the operating body can be measured simultaneously with the detection of the vibration when the vibration is generated, or can be measured at a timing different from the generation and detection of the vibration.

Regression analysis may be linear regression analysis or non-linear regression analysis. Linear regression analysis includes simple regression analysis, multiple regression analysis, polynomial regression analysis, and the like. Nonlinear regression analysis includes analysis using a neural network.

The selection of independent variables can be done using a stepwise method. The use of the stepwise method is preferred because it allows the selection of more significant independent variables. Note that the regression analysis can be performed using software such as Matlab (registered trademark) manufactured by MathWorks and Excel (registered trademark) manufactured by Microsoft.

The number of independent variables to be included in the regression formula (model formula) can be appropriately set according to the feel of use, the properties of the cosmetic, the purpose of evaluating the cosmetic, etc., and is not particularly limited. However, in order to reduce the risk of over-learning, the number of independent variables can be about 1 to 5, preferably 1 to 3. When there are multiple independent variables, multiple regression equations are constructed. Note that the regression equation may be a linear regression equation or may be a power regression equation. A suitable regression equation may be used according to the type of cosmetics.

When regression analysis is performed by linear regression analysis, the obtained linear regression formula is, for example, the sensory evaluation score estimate value y of the feeling of use as a dependent variable, and the data related to the time-dependent change in the vibration frequency spectrum (the above-mentioned statistic z1 to z16, values relating to friction of cosmetics, physical property values of cosmetics, etc.) When x ₁ , x ₂ , . . . , x _n are independent variables,
y= _a + _{b1x1 + b2x2 +} ...+ _bnxn
(where a is a constant and b ₁ , b ₂ , . . . _bn are normalization factors)
is represented by

Note that the coefficients described above are standardized coefficients obtained by standardizing each variable, but a regression equation may be created in which the coefficients are partial regression coefficients.

In the regression equation, one or more independent variables may be used. In that case, the above-mentioned value related to the magnitude of vibration is a first value related to the magnitude of vibration corresponding to a first predetermined elapsed time after application of the cosmetic and a first predetermined frequency; a second predetermined time after application and a second value for the magnitude of the vibration corresponding to the second predetermined frequency, wherein the independent variable includes the first value and the second value. good.

Feelings in use evaluated by performing regression analysis using data on changes in the frequency spectrum of vibration over time are not particularly limited, but are particularly sticky, refreshing, moist, penetrating, moist, taut, firm, and tactile. A significant estimation model can be constructed for the feeling of smoothness and mellowness in use.

In this embodiment, sensory evaluation of the feeling of use is performed by a specialized panel in order to construct the evaluation criteria, but it is also possible to construct the evaluation criteria using sensory evaluation by general users instead of the specialized panel. When the evaluation criteria are constructed using sensory evaluation by general users, it is possible to evaluate unknown cosmetics based on criteria closer to the tactile sensation that users actually feel. However, since the tactile sensations of general users are more varied than those of the specialized panel, it is necessary to collect data from a larger number of users than when sensory evaluation by the specialized panel is used.

Even when the sensory evaluation estimated by this embodiment is a time-series sensory evaluation, a database can be constructed in the same manner as in the sensory evaluation estimation that does not consider the time axis. In that case, the entire evaluation period of the time series sensory evaluation, the period from the start of application of the cosmetic to the elapse of a predetermined time (including the period from the start of application to the end of application, and the period from the end of application to the elapse of a predetermined time) good) can be estimated over a period of time. Estimating the evaluation in such a predetermined period may be estimating a representative value of the evaluation in the predetermined period. For example, it may be an estimation of a representative evaluation value, that is, a value representative of the evaluation values of the feeling of use in the first half, the middle half, or the second half of the evaluation period of the time-series sensory evaluation.

For the representative evaluation value, for example, time-series sensory evaluation is performed by a normal method, the results are represented by a graph, and a graph for one evaluation item is extracted. Then, the evaluation period is divided into a plurality of periods, for example, three periods of the first period, the middle period, and the second period. Then, the representative evaluation value in each period can be obtained as an integral value (area integral value), maximum value, average value (arithmetic average or geometric average), median value, or the like of the evaluation values in that period.

Furthermore, in the same way as in estimating the sensory evaluation value without considering the time axis, regression analysis is performed using the statistics v ₁ to v ₁₆ obtained by the vibration detection and data generation step and the above representative evaluation values. and obtain the relationship between the statistical quantity and the representative evaluation value. When the relationship is represented by a model formula, the dependent variable (objective variable) includes a representative evaluation value of the predetermined feeling of use, and the independent variable (explanatory variable) includes at least one of the statistics v ₁ to v ₁₆ . may contain.

(Evaluation of cosmetics)
The regression equation obtained as described above serves as an evaluation criterion for evaluating the feeling of use of cosmetics. In other words, by detecting and analyzing vibrations for each of a plurality of known cosmetics and performing sensory evaluation by a specialized panel, if evaluation criteria are established, data based on vibrations detected for unknown cosmetics can be collected. By acquiring and applying the constructed evaluation criteria, it is possible to estimate the sensory evaluation score of the feel of use of an unknown cosmetic material. At that time, the vibration detection and data generation of the unknown cosmetics are performed under the same conditions as the vibration detection and data generation performed when obtaining the evaluation criteria.

The cosmetic to be evaluated in this embodiment is not particularly limited as long as it can be easily spread on the skin with a finger or the like and can form a thin film on the skin. The bulk form of the cosmetics may be liquid, gel, cream, semi-solid, and the like. Cosmetics to be evaluated specifically include basic cosmetics such as lotions, milky lotions, and serums, makeup bases, foundations, hand creams, body creams, and the like.

<Apparatus for evaluating texture in use of cosmetics>
As shown in FIGS. 2 and 3A, the apparatus 1 for evaluating the feeling of use of cosmetics according to this embodiment moves the operating body 12 while bringing the operating body 12 into contact with the cosmetic applied to the surface 11 to be coated. Vibration detection means 20 for detecting vibrations generated by movement over time; Data generation means 30 for generating data on changes over time in the frequency spectrum of the vibrations from the detected vibrations; and evaluation means 40 for evaluating the feeling of use of the cosmetic.

<How to select cosmetics>
The method for evaluating the feel of use of cosmetics and the apparatus for evaluating feel of use of cosmetics described above can be used for selection of cosmetics and the like. For example, when it is desired to select one or more cosmetics having a desired feel in use from a group including a plurality of cosmetics whose feel in use is unknown, or to select one or more cosmetics having a feel in use that is the same as or close to the feel in use desired by the customer. This can be used, for example, when you want to recommend cosmetics to customers.

Specifically, one embodiment of the present invention includes a first evaluation step of evaluating the feel of use of the cosmetic _C0 using the above-described method of evaluating the feel of use of the cosmetic, and the feel of use of the above-mentioned cosmetic. a second evaluation step of evaluating the feeling in use of a plurality of selection target cosmetics C ₁ to C _n (n is an integer) different from the cosmetic C ₀ using a method of evaluating the cosmetic C a comparing step of comparing the feel in use of the _cosmetics C ₁ to C n with the feel in use of the plurality of cosmetics C ₁ to C _n ; and a selecting step of selecting from cosmetics C ₁ to C _n to be selected from . Here, it is preferable that the method of evaluating the feeling of use of the cosmetic used in the first evaluation step and the second evaluation step is the same.

In the above method of selecting cosmetics, the cosmetics _C0 may be, for example, cosmetics that customers or users like or usually use. In addition, the number of the plurality of cosmetics C ₁ to C _n is, for example, a group of cosmetics that the user wants to try using, or a group of cosmetics that the sales person or the like wants to recommend to the user (customer). can be The number of cosmetics C ₁ to C _n can be, for example, 2 to 20, preferably 3 to 10.

The texture in use evaluated in the first evaluation step and the second evaluation step in the method for selecting the cosmetic is the same. In addition, the above method of selecting cosmetics can be repeated multiple times for different textures in use. After that, as a final selection step, the cosmetics that have been selected the most times can be finally selected.

[Example 1]
The cosmetics were evaluated using an evaluation apparatus 1 as shown in FIG.

A few drops of a known cosmetic were spread on the inner skin of one forearm. A 3-axis acceleration sensor (manufactured by Tech Gihan Co., Ltd., model: A3AX) was attached to the side of the index finger on which the cosmetic was not dripped on the arm, and the finger was attached to the surface of the applied cosmetic. It was moved while applying a force of 2 N or less while contacting. At this time, the tip of the index finger was moved at a speed of less than about 30 cm/sec. The above operation was started immediately after the cosmetic material was dropped and spread, and continued for 60 seconds, during which vibrations were detected by the above three-axis acceleration sensor (detection means).

A short-time Fourier transform was performed on the vibrations detected for the cosmetics, and a distribution map showing positions with equal power spectral densities, created in the same format as that illustrated in FIG. 5, was obtained. At this time, the spectral diagram was generated using MATLAB (registered trademark) of MathWorks. The scatterplot displayed the power spectral density in the frequency range from 0 to 500 Hz.

Subsequently, the obtained distribution map was divided into multiple parts. In this example, as shown in FIG. 6, the vertical axis is divided into four (the frequency is divided into four: 0 Hz to 50 Hz, 50 Hz to 100 Hz, 100 Hz to 250 Hz, and 250 Hz to 500 Hz), and the horizontal axis is divided. (Divide the time into 4 parts: 0 seconds to 10 seconds, 10 seconds to 20 seconds, 20 seconds to 40 seconds, 40 seconds to 60 seconds) to form regions Z1 to Z16 in the spectrum diagram did. Furthermore, in each region, the arithmetic mean value of the power spectral density was obtained, and each value was defined as v ₁ to v ₁₆ .

A total of 20 types of known cosmetics were subjected to the detection and analysis of the above vibrations, and arithmetic mean values v ₁ to v ₁₆ were obtained for each cosmetic. On the other hand, a sensory evaluation was carried out for each of the plurality of cosmetics described above with respect to the tactile feeling of "freshness" when the cosmetics were applied by bringing them into contact with the skin for the first time. The sensory evaluation was evaluated by a score of relative comparison with a control sample by an expert panel.

Subsequently, using the above values v ₁ to v ₁₆ and the sensory evaluation score of “freshness” by a specialized panel, linear regression analysis was performed using Matlab (registered trademark) manufactured by MathWorks to obtain a regression equation. rice field. Selection of independent variables from values v ₁ to v ₁₆ was performed by a stepwise method. As a result, a formula of S=-0.949* _v14 was obtained, in which the estimated score S of the feel of use "freshness" was taken as the dependent variable, and _{v14 among} the values v1 to _v16 was taken as the independent variable. (analyzed with standardization for each variable). This means that the sensory evaluation score of the feel of use, “freshness,” can be significantly explained based on the magnitude of frequency components in a predetermined time band and a predetermined frequency band, which is _v14 .

FIG. 7 shows the relationship between the evaluation value (estimated value) S _estimated from the regression equation and the sensory evaluation value S0 by the expert panel. The estimated value S is a value obtained by substituting _v14 into the above regression equation for each of the plurality of known cosmetics. According to FIG. 7, each plot is aligned on a proportional straight line with a slope of approximately one. As a result, it was confirmed that the estimated value S _calculated from the regression equation obtained by the above-mentioned linear regression analysis for "freshness" was a value S0 close to the sensory evaluation score of the expert panel.

By using the evaluation criteria constructed as described above, it is possible to evaluate the feeling of use of an unknown cosmetic. At that time, for the feel of use of the unknown cosmetic, vibration detection and data generation are performed under the same conditions as those used in establishing the evaluation criteria. By substituting the value v ₁₄ obtained from the analysis of the unknown cosmetic into the above formula S=−0.949*v ₁₄ , an estimated value of the sensory evaluation score of the feel of use of the unknown cosmetic is obtained. be able to.

[Example 2]
Vibrations were detected and analyzed in the same manner as in Example 1, and arithmetic mean values of power spectral densities were obtained in each of the regions Z1 to Z16 of the spectral diagram, and each value was defined as v ₁ to v ₁₆ . A total of 21 types of known cosmetics were subjected to the detection and analysis of the above vibration, and values v ₁ to v ₁₆ were obtained for each cosmetic. On the other hand, in the same manner as in Example 1, a sensory evaluation was performed by a specialized panel on the feeling of "stickiness" in use for each of the plurality of known cosmetics.

Subsequently, a linear regression analysis was performed in the same manner as in Example 1, except that the texture in use was set to "sticky", and a linear regression equation was obtained. As a result, a formula of S=−0.929*v ₁₀ was obtained, in which the estimated score S of the touch feeling in use of “stickiness” was taken as the dependent variable and v ₁₀ among the values v ₁ to v ₁₆ was taken as the independent variable. This means that the sensory evaluation score of “sticky feeling” in use can be significantly explained based _on the magnitude of frequency components in a predetermined time band and a predetermined frequency band, which is v10.

FIG. 8 shows the relationship between the evaluation value (estimated value) S _estimated from the regression equation and the sensory evaluation value S0 by the expert panel. The estimated value S is a value obtained by substituting _v10 into the above regression equation for each of a plurality of known cosmetics. According to FIG. 8, each plot is aligned on a proportional straight line with a slope of approximately one. As a result, it was confirmed that the estimated value S calculated from the regression equation obtained by the above-mentioned linear regression analysis for "stickiness" was close to the sensory evaluation score _S0 of the expert panel.

By using the evaluation criteria constructed as described above, it is possible to evaluate the feel of use of unknown cosmetics. At that time, for the feel of use of an unknown cosmetic, vibration detection and data generation are performed under the same conditions as those used in establishing the evaluation criteria. By substituting v ₁₀ among the values obtained by analyzing the vibration obtained from the unknown cosmetic into the above formula S = -0.929 * v ₁₀ , the sensory evaluation of the feel of use of the unknown cosmetic is performed. An estimate of the score can be obtained.

[Example 3]
In Examples 1 and 2, the skin on the inner side of the forearm was used as the surface to be coated, and the fingertip of the index finger was used as the action object. That is, in Examples 1 and 2, the human body was used as the vibration generating means 10 . On the other hand, in Example 3, synthetic leather (manufactured by Komatsu Seiren Co., Ltd., trade name: Suprale (registered trademark)) was used as the surface to be coated in the vibration generating means 10 . Specifically, the synthetic leather was attached to a table with a flat surface, the cosmetics were dropped and spread in the same manner as in Example 1, and vibration was detected in the same manner as in Examples 1 and 2. In Example 3, the time during which the finger was moved was set to 90 seconds from immediately after the cosmetic material was dropped and spread.

In the same manner as in Example 1, a spectrum diagram (distribution diagram) displaying positions where the power spectral densities are equal is obtained, and in the same manner as in Example 1, power spectral densities are obtained in each divided region in the spectrum diagram. The average value was obtained and each value was v ₁ to v _16. Regarding the horizontal axis of the spectral diagram, the time interval was 0 seconds to 15 seconds, 15 seconds to 30 seconds, 30 seconds to 45 seconds, 45 seconds. It was divided into 4 parts of more than 90 seconds and less than 90 seconds.

In the same manner as in Example 2, a sensory evaluation was performed by a specialized panel on the feel of use of “stickiness”, and linear regression analysis was performed using the above values v ₁ to v ₁₆ and sensory evaluation values by the specialized panel, and a linear regression equation was obtained. asked. As a result, the estimated score S of the feeling in use of “stickiness” is taken as the dependent variable, and v ₁₄ and v ₄ among the values v ₁ to v ₁₆ are taken as the independent variables, S=−0.675*v ₁₄ −0.309. * _v4 was obtained. This means that the sensory evaluation score of "sticky feeling" in use can be significantly explained based _on the magnitude of the frequency components in the predetermined time band of _v14 and v4 and the predetermined frequency band.

FIG. 9 shows the relationship between the evaluation value (estimated value) S _estimated from the regression equation and the sensory evaluation value S0 by the expert panel. The estimated value S is a value obtained by substituting v ₁₄ and v ₄ into the above regression equation for each of the plurality of known cosmetics. According to FIG. 9, each plot is aligned on a proportional straight line with a slope of approximately one. As a result, it was confirmed that the estimated value S calculated from the regression equation obtained by the above-mentioned linear regression analysis for "stickiness" was close to the sensory evaluation score _S0 of the expert panel.

By using the evaluation criteria constructed as described above, it is possible to evaluate the feel of use of unknown cosmetics. At that time, for the feel of use of an unknown cosmetic, vibration detection and data generation are performed under the same conditions as those used in establishing the evaluation criteria. By substituting z ₁₄ and v ₄ among the values obtained by analyzing the vibration obtained from the unknown cosmetic into the above formula S=−0.675*v ₁₄ −0.309*v ₄ , It is possible to obtain an estimated sensory evaluation score for the feel of use of an unknown cosmetic.

[Example 4]
Example 4 is an example in which the sensory evaluation is a time-series sensory evaluation, and a model formula for use in estimating the time-series sensory evaluation was created.

Vibration was generated and detected in the same manner as in Example 1. Then, the vibration was analyzed in the same manner as in Example 1, and arithmetic mean values of the power spectral densities in the regions Z1 to Z16 of the spectral diagram were obtained, and the respective values were defined as v ₁ to v ₁₆ . A total of six known cosmetics were subjected to the above vibration detection and analysis, and values v ₁ to v ₁₆ were obtained for each cosmetic.

On the other hand, time series sensory evaluation was performed by 40 general panelists by the TCATA method for each of the plurality of known cosmetics described above. More specifically, the subject is asked to start applying the cosmetic and apply it. Removed missing textures each time. The selection and cancellation of items are input through the input device of the personal computer, and the results of the input can be displayed on the display device of the personal computer. In this example, the evaluation items were four items of "thickness", "light spreadability", "freshness", and "tackiness".

Subsequently, the data input to the personal computer were processed by the processing device of the personal computer using software (sensory evaluation software FIZZ, manufactured by BIOSSYSTEMS). In the data processing, the ratio of subjects who selected each feeling of use for each unit of time was calculated as the degree of superiority, plotted over time, and the results were displayed as a graph. Note that if all the subjects selected a given feeling of use at a certain point in time, the degree of superiority would be 100%. The priority becomes 0%.

FIG. 10 shows a graph of the above results. In the graph of FIG. 10, the horizontal axis is time (sec) and the vertical axis is priority (%). Changes in sensory evaluation in chronological order for each feeling of use are shown. In this example, the graph of the feeling of use "thickness" is extracted from the graphs of the plurality of feeling of use shown in the drawing. FIG. 11 shows the graph after extraction.

Furthermore, the graph in FIG. 11 is divided into three parts along the time axis, namely, the first half, the middle half, and the second half. Since the total evaluation period was 100 seconds, each of the early, middle, and late periods was approximately 33 seconds. Then, a representative evaluation value of the feel of use, which is “thick”, was determined for each period. In this example, the average values P _a4 , P _b4 , and P _c4 of the degrees of superiority in each period are obtained as representative evaluation values and used as representative evaluation values in each period.

In Example 4, a model formula was obtained using the late average value P _c4 of the above representative evaluation values and the values v ₁ to v ₁₆ obtained as described above. The model formula was determined by performing regression analysis using Matlab (registered trademark) manufactured by MathWorks in the same manner as in Example 1. Selection of independent variables from values v ₁ to v ₁₆ was also performed by the stepwise method as in Example 1.

As a _{result, P c4 = −41.733 *(logv 6 ) −} 228.93 (R ² =0.7109) was obtained. From this result, it was found that the evaluation of the tactile feeling of “thickness” in the latter half of the evaluation period in the TCATA method can be significantly explained based on the magnitude of the frequency components in the predetermined time band and the predetermined frequency band. . FIG. 12 graphically shows the relationship between P _c4 and logv ₆ .

By constructing and storing the evaluation criteria in this way, it is possible to estimate the evaluation in a predetermined evaluation period of the time-series sensory evaluation of the feel of use of an unknown cosmetic. At that time, for the feel of use of an unknown cosmetic, vibration detection and data generation are performed under the same conditions as those used in establishing the evaluation criteria. As a result, by substituting the value v6 obtained from the analysis of the unknown cosmetic into the above model _formula , the use tactile sensation of "thickness" when the unknown cosmetic is subjected to time-series sensory evaluation. , the representative value (average value of dominance) in the later period of the evaluation period can be estimated.

[Example 5]
As in Example 4, acquisition and analysis of data on the frequency spectrum of vibration, time-series sensory evaluation, and the like were performed. However, in Example 5, a model formula was created for the feel of use "tackiness" in place of the feel of use "thickness".

From the graph of the time-series sensory evaluation (Fig. 10) obtained in the same manner as in Example 4, a graph of the feeling of use called "sticky feeling" was extracted. It was divided into three parts, the first half, the middle half, and the second half. Then, a representative evaluation value of the feeling of use called “tackiness” was obtained for each period. In this example, the average values P _a5 , P _b5 , and P _c5 of the degrees of superiority in each period are calculated and used as representative evaluation values in each period. FIG. 13 shows the graph after extraction.

A model formula was obtained using the average value P _a5 of the previous period and the values v ₁ to v ₁₆ obtained as described above, among the above representative evaluation values. The method of obtaining the formula is the same as in the fourth embodiment. As a result, a formula (R ² =0.839) of P _a5 =−16.248*(logv ₆ )−89.607 was obtained. From this result, it was found that the following evaluation of the evaluation period in the TCATA method of the tactile sensation of "tacky feeling" can be significantly explained based on the magnitude of the frequency component in a predetermined time band and a predetermined frequency band. FIG. 14 shows a graph representing the relationship between _Pa5 and _logv6 .

The model formula constructed in this manner can be saved as an evaluation criterion. Therefore, regarding the feeling of use of an unknown cosmetic, vibration detection and data generation are performed under the same conditions as those used in establishing the evaluation criteria, and the value v6 obtained from the analysis of the unknown cosmetic is calculated using the above model _formula . By substituting into , it is possible to estimate the representative value (average value of superiority) in the first half of the evaluation period for the tactile sensation of "stickiness" when performing time-series sensory evaluation of unknown cosmetics. .

1 Evaluation Device 10 Vibration Generation Means 11 Coated Surface 12 Operating Body 15 Cosmetic 20 Vibration Detection Means 30 Data Generation Means 40 Evaluation Means

Claims (20)

a vibration detection step of detecting over time vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated;
a data generating step of generating, from the detected vibrations, data relating to changes in the frequency spectrum of the vibrations over time;
Using the generated data, the tactile feel of the cosmetic in use is evaluated based on the relationship between the previously obtained data relating to changes in the frequency spectrum of vibration over time and the sensory evaluation of the tactile feel in use of the cosmetic. an evaluation step;
Seeking the relationship
For each of a plurality of cosmetics, obtaining a sensory evaluation value of the feeling in use and generating data on changes over time in the frequency spectrum of vibration,
Create a power spectral density distribution map with one of the vertical and horizontal axes as time and the other as frequency from data on changes in the frequency spectrum of vibration over time,
dividing the distribution map vertically and horizontally to form a plurality of regions;
calculating power spectral density statistics in each of the plurality of regions;
A method of evaluating the feel of a cosmetic in use, comprising performing a regression analysis using at least each of the statistics as an independent variable and the sensory evaluation value as a dependent variable. 2. The method of claim 1, wherein the statistic is at least one of an arithmetic mean, a geometric mean, a median, a maximum, and a sum of the power spectral densities in the region. 3. The method according to claim 1 or 2, wherein the independent variables further include at least one of a viscosity of the cosmetic, a first normal stress difference, an amount of deformation of the operating body, and a value related to friction of the cosmetic. . 3. The method according to claim 1, wherein, in said vibration detecting step, vibration transmitted to said surface to be coated and/or said operating body is detected. 3. The method according to claim 2, wherein the sensory evaluation of the feeling of use of the cosmetic comprises a time series sensory evaluation. 6. The method according to claim 5, wherein the sensory evaluation of the feel of use of the cosmetic is a representative value of the time-series sensory evaluation over a predetermined period. a vibration detection step of detecting over time vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated;
a data generating step of generating, from the detected vibrations, data relating to changes in the frequency spectrum of the vibrations over time;
and an evaluation step of using the generated data to evaluate the feel of use of the cosmetic when the cosmetic is spread. a vibration detection step of detecting over time vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated;
a data generating step of generating data on changes in the frequency spectrum of the vibration over time over 30 to 150 seconds after application to the surface to be coated, from the detected vibration;
and an evaluation step of evaluating the feel of use of the cosmetic using the generated data. 8. The tactile feel of the cosmetic in use is evaluated in the evaluation step based on a previously obtained relationship between data relating to temporal changes in the frequency spectrum of vibration and a sensory evaluation of the tactile feel of the cosmetic in use. Or the method according to 8. 9. The method according to claim 7 or 8, wherein the data on changes over time in the frequency spectrum of vibration include values on magnitude of vibration corresponding to a predetermined elapsed time and a predetermined frequency after application of the cosmetic material. 11. The method according to claim 10, wherein the value related to the magnitude of vibration includes statistics of power spectral density in a predetermined elapsed time band and a predetermined frequency band after application of the cosmetic. The statistic is at least one of an arithmetic mean value, a geometric mean value, a median value, a maximum value, and a total value of the power spectral density in a predetermined elapsed time band and a predetermined frequency band after application of the cosmetic. 12. The method of claim 11 . 10. The method according to claim 9, wherein the relationship is given by a regression equation, in which the independent variable includes a value related to the magnitude of the vibration, and the dependent variable includes a sensory evaluation of the feeling of use of the cosmetic. . A first value related to the magnitude of vibration corresponding to a first predetermined elapsed time and a first predetermined frequency after application of the cosmetic; a second value for the magnitude of vibration corresponding to two predetermined elapsed times and a second predetermined frequency;
14. The method of claim 13, wherein said independent variable comprises said first value and said second value. 14. The method of claim 13, wherein the independent variables further include at least one of a viscosity of the cosmetic, a first normal stress difference, an amount of deformation of the working body, and a value related to friction of the cosmetic. 3. The method according to claim 1, wherein, in said vibration detecting step, vibration transmitted to said surface to be coated and/or said operating body is detected. 3. The method according to claim 2, wherein the sensory evaluation of the feeling of use of the cosmetic comprises a time series sensory evaluation. 18. The method according to claim 17, wherein the sensory evaluation of the feel of use of the cosmetic is a representative value of the time-series sensory evaluation over a predetermined period. vibration detection means for detecting over time vibrations generated by moving the action body while the action body is in contact with the cosmetic applied to the surface to be coated;
data generation means for generating data on changes in the frequency spectrum of the vibration over time from the detected vibration;
Using the generated data, the tactile feel of the cosmetic in use is evaluated based on the relationship between the previously obtained data relating to changes in the frequency spectrum of vibration over time and the sensory evaluation of the tactile feel in use of the cosmetic. and an evaluation means;
The evaluation means is
For each of a plurality of cosmetics, obtaining a sensory evaluation value of the feeling in use and generating data on changes over time in the frequency spectrum of vibration,
Create a power spectral density distribution map with one of the vertical and horizontal axes as time and the other as frequency from data on changes in the frequency spectrum of vibration over time,
dividing the distribution map vertically and horizontally to form a plurality of regions;
calculating power spectral density statistics in each of the plurality of regions;
An apparatus for evaluating the feel of cosmetics in use, comprising means for performing regression analysis using at least each of the statistics as an independent variable and the sensory evaluation value as a dependent variable. A first evaluation step of evaluating the feel of use of a cosmetic using the method for evaluating the feel of use of a cosmetic according to claim 1 or 7;
A second evaluation step of evaluating the feel of use of a plurality of selected cosmetics, different from the cosmetics, using the method of evaluating the feel of use of cosmetics used in the first evaluation step;
a comparison step of comparing the feel of use of the cosmetic with the feel of use of each of the plurality of selection target cosmetics;
and a selecting step of selecting a cosmetic having a feel in use that is closest to the feel in use of the cosmetic from among the plurality of cosmetics to be selected.

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