JP2002224086A - Evaluation method for hair physical property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate the physical property of hair by measuring the outer diameter of a plurality of parts of the hair, calculating the short diameter, the long diameter, and the mean cross section of the hair, and reflecting either one or more numerical values on the physical properties of the hair as variables. SOLUTION: This evaluation method for the hair physical properties is characterized in that the outer diameters of the plurality of parts of the hair are measured by an optical outer diameter measuring means using a laser beam so as to calculate the short diameter, the long diameter, and the mean cross section of the hair, and either one or more of the short diameter, the long diameter, and the mean cross section are reflected on the physical characteristic value of the hair as the variables.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for evaluating physical properties of hair.

[0002]

2. Description of the Related Art Conventionally, when expressing the feeling of touching hair with a hand or expressing the effect of various hair treatment agents (hair care agents) by numerical values, the bending stress, tension, Physical properties such as stress, torsional stress, frictional force, and heat transfer properties are used. The physical properties of hair vary depending on the thickness and flatness of the hair, and the portion where the thickness and flatness of the hair contribute to the hair physical properties is large. Conventionally known methods for measuring the thickness and flatness of hair include measuring the minor axis of the hair using calipers, measuring the major axis of the hair using a microscope (microscope), and obtaining the minor axis or major axis obtained. Is assumed to be the thickness of the hair with any of the above values, and evaluated by physical property values reflected as variables. However, setting the thickness of the hair using only the short diameter or the long diameter does not represent the exact thickness and flatness of the sample hair. Did not. or,
In the measurement with a caliper and the microscope,
Since pressure is applied to the measuring part of the hair, it has been difficult to measure the exact diameter of the elastic hair. Furthermore, when measuring both the minor axis and the major axis, the minor axis is measured with a vernier caliper, and the major axis is measured separately with a microscope.
There is a disadvantage that the measurement is complicated and requires a lot of time.

[0003]

SUMMARY OF THE INVENTION The present invention calculates the short diameter, long diameter and average cross-sectional area of hair by measuring the outer diameter of a plurality of points of the hair, and uses any one or more numerical values as variables. The property value of the hair is reflected in the property value of the hair to evaluate the property value of the hair.

[0004]

In order to solve the above-mentioned problems, the present invention employs an optical outer diameter measuring means using a laser beam to measure the outer diameter of hair at a plurality of locations, thereby shortening the hair length. The method is characterized in that a diameter, a major axis, and an average cross-sectional area are calculated, and one or more of the minor axis, the major axis, and the average cross-sectional area are reflected in physical property values of the hair as variables.

It is characterized in that the bending stress of the hair is evaluated by the Young's modulus with π × (minor diameter) ³ × (long diameter) 径 64 as a variable.

Π × (minor axis) × (major axis) × ((minor axis) ² + (major axis) ² )
It is characterized in that the torsional stress of the hair is evaluated by the rigidity with # 64 as a variable.

It is characterized in that the tensile stress of hair is evaluated by the Young's modulus with π × (minor axis) × (major axis) ÷ 4 as a variable.

[0008] It is characterized in that the frictional force of the hair is evaluated by a friction coefficient with π × (((minor diameter) ² + (long diameter) ² ) ÷ 2) ^1/2 as a variable.

The contact angle of the hair with water is evaluated by using a contact angle with π × (((minor diameter) ² + (long diameter) ² ) ÷ 2) ^1/2 as a variable. .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below. The present invention provides a measuring device for rotating a hair around its axis while applying tension to the hair while supporting the hair, and detecting the width of the hair in an optically non-contact manner using a laser beam. And measuring the major axis, and moving the optical outer diameter measuring means along the hair axis to measure the major axis and minor axis at a plurality of locations. Calculates the minor axis, major axis, average oblateness and average cross-sectional area of the hair, and reflects at least one of the minor axis, major axis, and average cross-sectional area as a variable in the physical properties of the hair. Things.

The optical outer diameter measuring means comprises means for measuring the outer diameter of the hair by irradiating a laser beam, and by rotating the hair around the axis of the hair while applying tension to the hair and supporting it. In addition to measuring the major axis and minor axis of the hair, the optical measuring means is moved along the hair axis to measure a plurality of locations to obtain data of the major axis and minor axis at a plurality of measuring points within a predetermined length range. Based on the data of the major axis and minor axis of the plurality of measurement points obtained, the average value is defined as the minor axis or major axis of the hair. Further, the oblateness and the cross-sectional area at a plurality of locations are obtained from the measured values of the plurality of outer diameters, and the average value is obtained. The optical measuring means is most preferably a hair measuring device, which was previously filed by the present applicant as Japanese Patent Application No. 2000-057703, but is not limited thereto. Any means can be used as long as it can measure the width of any part of the hair in a non-contact manner by an optical means such as a laser beam. For example, the hair disclosed in JP-A-3-289942 can be measured. It is also possible to use a device that performs the above. By such an optical measuring means, it is possible to measure the major axis and the minor axis of the hair with high efficiency.

According to the present invention, the data of the major axis and the minor axis of the hair measured by the optical measuring means are measured at a plurality of locations within a predetermined length range of the hair, and an average value of the plurality of measurement locations is used. There is a feature in the point. By using the average value of the minor axis, major axis, oblateness, and cross-sectional area of a plurality of points in a predetermined length range, it is possible to avoid inaccuracy of data due to specificity or damage of hair at a measurement point, and It is possible to perform highly sensitive evaluation with high accuracy. In general, it is known that the cross-sectional shape of hair is an ellipse or a shape close to an ellipse or, to a lesser extent, a shape close to a triangle such as a conical shape. Therefore, by using a laser beam optical outer diameter measuring device, the hair is rotated 360 degrees, the hair diameter is measured every one time, and the same measurement is performed on a plurality of places of the hair to obtain the long diameter, the short diameter, and the flatness. It is possible to almost accurately estimate the cross-sectional properties of the hair, such as the ratio and the cross-sectional area. Then, such information is reflected as a variable in the physical property value to evaluate the hair properties.

Using a laser beam, an outer diameter measuring device measures the major axis and minor axis by rotating the hair by 360 degrees, and further measures the major axis and minor axis at a plurality of locations on the hair to reduce the pressure. Since the measurement can be performed in a state where the hair is not applied, the average minor axis, average major axis, and average flatness of the hair can be calculated. By calculating the average minor axis, average major axis, and average flatness of the hair, the average cross-sectional area of the hair can be accurately and easily calculated, and the bending measurement, the tension measurement,
In evaluating torsion measurement, friction measurement, heat transfer measurement, and contact angle measurement with water, it is possible to judge which value of the minor axis, major axis, flatness, and cross-sectional area of the hair is optimally incorporated into the physical property values as variables. Physical properties can be accurately evaluated. Further, the hair diameter and the flatness can be easily and quickly measured by the method.

[0014]

EXAMPLES The major axis (.alpha.) And minor axis (.beta.) Of hair were measured by the optical outer diameter measuring apparatus shown in FIGS. The optical measuring device fixes the both ends of the hair (1) with the chucks (2) and rotates the hairs (1) by rotating the chucks (2) at both ends in synchronization with each other. 3) and the light receiving section (4) are used to optically measure the width of the crossing part of the hair to determine the major axis (α) and minor axis (β) of the hair. The measurement was 3 cm shown in FIG.
In the range of length (l), a plurality of locations S1 to S7 were measured at predetermined intervals. Then, the oblateness and the cross-sectional area are calculated from the major axis (α) and the minor axis (β) in each measurement unit, and the average value at seven locations is determined. The measurement at seven points along the axis of the hair is performed by synchronizing the laser beam irradiation part (3) and the light receiving part (4) at a fixed distance of 6
Move twice and measure.

[0015] The hair is made 360
After rotation, the major axis and the minor axis were measured at intervals of 2 mm, and the average secondary moment of area was calculated. The second moment of area is represented by π × (minor axis) ³ × (major axis) ÷ 64. When the hair was bent to a curvature of 2.5 cm ^-1 , the change in bending stress with respect to the curvature was measured as bending hardness (B value). FIG. 3 shows the evaluation of the bending hardness, the minor axis, the major axis, and the second moment of area. As is clear from FIG. 3, π ×
It can be understood that the bending hardness with (minor diameter) ³ × (long diameter) ÷ 64 as a variable, that is, the evaluation based on the Young's modulus is optimal. The measurement time by this method is 12.5 minutes on average, and the conventional method of measuring the short diameter with a vernier caliper and the long diameter with a microscope requires an average of 96.4 minutes, thereby greatly reducing the measurement time. I was able to do it.

By the same optical measurement method, the hair
Measure the major axis and minor axis at intervals of 5 mm by rotating it by 0 degrees, and
The average secondary moment of shear was calculated. Note that the secondary pole
Π × (minor axis) × (major axis) × ((minor axis)^Two+ (Long diameter)^Two) ÷
It is represented by 64. The time required for measurement is measured by the conventional method.
Although the average was 115 minutes by default, the method of the present invention
The average was 10.0 minutes. Hair up to 1080 degrees
When twisting, twist angle between 360 degrees and 720 degrees
The change in torsional stress with respect to the torsional angle
(B value) was evaluated. Fig. 4 shows the evaluation for torsional torque.
Indicate the value. As is apparent from FIG.
π × (minor axis) × (major axis) × ((minor axis)^Two+ (Long diameter) ^Two÷ ¥ 64 is a variable
The optimum torsional torque, i.e., the rigidity
I can understand that

By the same optical measurement method, the hair
After rotation by 0 °, the major axis and minor axis were measured at intervals of 5 mm, and the average cross-sectional area was calculated. The cross-sectional area is π × (short diameter) × (long diameter)
It is represented by $ 4. The time required for the measurement was 96.2 minutes on average in the measurement by the conventional method, while it was 12.0 minutes in the method of the present invention. Tensile stiffness is the change in tensile stress with respect to elongation when 50 mm hair is extended by 2%
(B value) was measured. FIG. 5 shows the evaluation of the tensile rigidity. As is clear from FIG. 5, for the tensile measurement, the evaluation based on the cross-sectional area, that is, the Young's modulus using π × (minor axis) × (major axis) ÷ 4 as a variable was optimal.

By the same optical measurement method, the hair
Measure the major axis and minor axis at intervals of 5 mm by rotating it by 0 degrees, and
The uniform section circumference was calculated. The cross-sectional circumference is π × ((((minor diameter)^Two
+ (Long diameter)^Two) ÷ 2)^1/2Is approximated by Time required for measurement
Was 92.5 minutes on average in the measurement by the conventional method.
On the other hand, it took 10.5 minutes in the method of the present invention. A piece of hair
Put the friction wire around the piano wire on top of the 1mm / sec.
Depending on the speed, when sliding the friction element over 30mm
The stress was measured as a coefficient of friction. Figure 6 shows the coefficient of friction
The evaluation is shown below. As is clear from FIG.
Is π × ((((minor axis) ^Two× (major axis)^Two) ÷ 2)^1/2Is a variable
Optimal evaluation of hair frictional force based on coefficient of friction
It can be understood.

By the same optical measurement method, the hair
After rotation by 0 °, the major axis and minor axis were measured at 1 mm intervals, and the average cross-sectional circumference was calculated. The cross-sectional circumference is π × ((((minor diameter) ²
× (major axis) ² ) ÷ 2) It is approximated by ^1/2 . The time required for the measurement was 100.5 minutes on average in the measurement by the conventional method, whereas it was 10.5 minutes in the method of the present invention. 1 μl of ion-exchanged water was dropped on one piece of hair and photographed with a microscope, and the angle between the formed water drop and the hair was measured as a contact angle. FIG. 7 shows the evaluation for the contact angle. As is clear from FIG.
× (((minor axis) ² + (major axis) ² ) ÷ 2) The evaluation at the contact angle with the variable of ^1/2 was optimal.

[0020]

According to the present invention, the minor axis, major axis, and cross-sectional area of hair are measured by an optical outer diameter measuring method, and at least one of minor axis, major axis, and cross-sectional area is used as a physical variable of hair. Since the hair properties are evaluated by reflecting them in the characteristic values, the hair properties can be evaluated accurately and in a short time.

[Brief description of the drawings]

FIG. 1 is an explanatory view conceptually illustrating an optical measuring means.

FIG. 2 is a cross-sectional view of the hair

FIG. 3 is a graph showing evaluation for bending stress.

FIG. 4 is a graph showing evaluation for torsional stress.

FIG. 5 is a graph showing evaluation for tensile stress.

FIG. 6 is a graph showing an evaluation of a coefficient of friction.

FIG. 7 is a graph showing an evaluation of a contact angle with water.

[Explanation of symbols]

 (1) Hair (2) Chuck part (3) Laser light irradiation part (4) Light receiving part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takayuki Arai 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture Shiseido Research Center (Shin-Yokohama) F-term (reference) 2F065 AA26 AA31 AA65 BB12 CC16 DD06 FF02 GG04 HH13 HH15 JJ09 MM04 MM28 PP11 PP13 QQ00 QQ21 QQ42 4C038 VB21 VC01

Claims (6)

[Claims] 1. An outer diameter measuring means using a laser beam to measure the outer diameter of hair at a plurality of positions to calculate the short diameter, long diameter and average cross-sectional area of the hair, and to use the short diameter, long diameter and average as variables. A method for evaluating physical properties of hair, wherein at least one of the cross-sectional areas is reflected in a physical property value of hair. 2. The evaluation method according to claim 1, wherein the bending stress of the hair is evaluated by a Young's modulus with π × (minor axis) ³ × (major axis) ÷ 64 as a variable. (3) π × (minor axis) × (major axis) × ((minor axis) ² + (major axis) ² )
2. The evaluation method according to claim 1, wherein the torsional stress of the hair is evaluated by using a rigidity with # 64 as a variable. 4. The evaluation method according to claim 1, wherein the tensile stress of the hair is evaluated by a Young's modulus with π × (minor axis) × (major axis) ÷ 4 as a variable. 5. The method according to claim 1, wherein the frictional force of the hair is evaluated by a friction coefficient having π × (((minor diameter) ² + (long diameter) ² ) ÷ 2) ^1/2 as a variable. Item 1. The evaluation method according to Item 1. 6. The method according to claim 1, wherein the contact angle of the hair with water is evaluated by a contact angle with π × (((minor axis) ² + (major axis) ² ) ÷ 2) ^1/2 as a variable. The evaluation method according to claim 1, wherein