JP2022021759A - Method for calculating modulus of elasticity of fiber sample, system for calculating modulus of elasticity of fiber sample, method for evaluating hair cosmetics, method for manufacturing hair cosmetics, and method for determining hair cosmetics - Google Patents

Abstract

To easily calculate the modulus of elasticity of a fiber sample.SOLUTION: A method for calculating the modulus of elasticity of a fiber sample calculates the modulus of elasticity of layers of the fiber sample that has the plurality of layers composed of different types of materials. The method for calculating the modulus of elasticity of the fiber sample includes the steps of: preparing a plurality of fiber samples collected from the same subject, the fiber samples in a number equal to or more than the number of the layers of the fiber sample; specifying a cross-sectional secondary moment of the layers of the fiber samples; for each of the fiber samples, with only one end of the fiber sample being fixed and the other end being applied with a predetermined load, measuring the length between the fixed position and the other end of the fiber sample and the amount of bending at the other end; and calculating the modulus of elasticity of the layers of the fiber sample from the cross-sectional secondary moment of the fiber samples, the length between the fixed position and the other end of the fiber sample, and the amount of bending at the other end.SELECTED DRAWING: Figure 7

Description

There is an application for application of Article 30, Paragraph 2 of the Patent Law. Date of issue June 3, 2nd year of Reiwa 2. Publications Proceedings of the 2020 Textile Society Annual Conference 3. Published by Masato Isobe

The present invention is a method for calculating the elastic modulus of a fiber sample, a system for calculating the elastic modulus of a fiber sample used in the method of calculating the elastic modulus of a fiber sample, and a hair cosmetic for treating hair using the calculation of the elastic modulus of a fiber sample. The present invention relates to a method of evaluating a sample, a method of manufacturing a hair cosmetic based on the evaluation result, and a method of determining a hair cosmetic.

The feel of an object made of a fiber material changes depending on the bending rigidity and elastic modulus of the fiber material. As a method for measuring the flexural rigidity of the elastic modulus of each fiber sample contained in the fiber material, for example, the method described in Non-Patent Document 1 is known.

Further, as a method for measuring the elastic modulus of a fiber sample which is a part of a fiber material, for example, the methods described in Patent Documents 1 and 2 and Non-Patent Document 2 are known. These documents show, as a typical fiber sample, a method of calculating the elastic modulus of hair.

Japanese Unexamined Patent Publication No. 2012-225652 Japanese Unexamined Patent Publication No. 2005-331283

Journal of the Society of Cosmetic Chemists, Vol 29, No.8 p469-485 J. Soc. Cosmet. Chem. Jpn Vol.36, No3 p207-p216

However, the method described in Patent Document 1 requires a large number of measurements in order to calculate the elastic modulus of the fiber sample. Further, in the method described in Patent Document 2, the elastic modulus is calculated from the observation of the cross section of the fiber sample using an atomic force microscope. It is not easy to observe the cross section using an atomic force microscope. Further, in the method described in Non-Patent Document 2, the outer layer of the hair is peeled off in order to measure the elastic modulus of each layer of the hair. The work of peeling off the outer layer of hair is not easy and time-consuming. That is, in these methods, it takes time and effort to calculate the elastic modulus of the fiber sample, and precise observation and work are required, and it is not easy to obtain the elastic modulus of the fiber sample.

The present invention has been made in consideration of such points, and an object of the present invention is to easily calculate the elastic modulus of a fiber sample.

The method for calculating the elastic modulus of the first fiber sample of the present invention is
The process of specifying the moment of inertia of area of the fiber sample and
A step of measuring the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end while fixing only one end side of the fiber sample and applying a predetermined load to the other end. ,
The present invention comprises a step of calculating the elastic modulus of the fiber sample from the moment of inertia of area of the fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end.

In the method for calculating the elastic modulus of the first fiber sample of the present invention, the step of specifying the moment of inertia of area may include a step of measuring the outer diameter of the fiber sample.

The method for calculating the elastic modulus of the second fiber sample of the present invention is a method for calculating the elastic modulus of each layer of the fiber sample having a plurality of layers made of different materials.
A step of preparing a plurality of fiber samples collected from the same subject and having a number of fiber samples equal to or larger than the number of layers of the fiber sample.
The process of specifying the moment of inertia of area of each layer of each fiber sample,
For each fiber sample, with only one end side of the fiber sample fixed and a predetermined load applied to the other end, the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end. And the process of measuring
The present invention comprises a step of calculating the elastic modulus of each layer of the fiber sample from the moment of inertia of area of each fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end.

In the method for calculating the elastic modulus of the second fiber sample of the present invention, the step of specifying the moment of inertia of area of each layer may include the step of measuring the outer diameter of the fiber sample and the thickness of each layer.

In the method for calculating the elastic modulus of the second fiber sample of the present invention, the number of the fiber samples prepared in the step of preparing the fiber samples may be larger than the number of layers of the fiber samples.

In the method for calculating the elastic modulus of the first or second fiber sample of the present invention, the fiber sample may be the hair of a mammal.

The elastic modulus calculation system of the fiber sample of the present invention is
A device that measures the moment of inertia of area of a fiber sample,
A device for measuring the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end in a state where only one end side of the fiber sample is fixed and a predetermined load is applied to the other end. ,
A device for calculating the elastic modulus of the fiber sample from the moment of inertia of area of the fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end is provided.

In the elastic modulus calculation system of the fiber sample of the present invention, the device for measuring the moment of inertia of area of the fiber sample may measure the outer diameter of the fiber sample.

In the elastic modulus calculation system of the fiber sample of the present invention, the device for calculating the elastic modulus of the fiber sample is the moment of inertia of area for each of the plurality of fiber samples, between the fixed position and the other end of the fiber sample. The elastic modulus of the fiber sample may be calculated from the length of the fiber sample and the amount of deflection at the other end of the fiber sample.

The evaluation method of the hair cosmetic of the present invention is
The step of calculating the elastic modulus of hair by the method of calculating the elastic modulus of any of the fiber samples described above, and
The process of treating the hair with a hair cosmetic and
A step of calculating the elastic modulus of the hair after being treated with the hair cosmetic by the method for calculating the elastic modulus of any of the fiber samples described above, and
The present invention comprises a step of comparing the elastic modulus of the hair before being treated with the hair cosmetic and the elastic modulus of the hair after being treated with the hair cosmetic.

The method for producing a hair cosmetic of the present invention includes a step of adjusting the components of the hair cosmetic based on the above-mentioned method for evaluating the hair cosmetic.

The method for determining the hair cosmetic of the present invention is
The process of receiving hair donations and
A step of calculating the elastic modulus of the provided hair by the method of calculating the elastic modulus of any of the fiber samples described above, and
The process of treating the hair with a hair cosmetic and
A step of calculating the elastic modulus of the hair after being treated with the hair cosmetic by the method for calculating the elastic modulus of any of the fiber samples described above, and
From the comparison between the elastic modulus of the hair before treatment with the hair cosmetic and the elastic modulus of the hair after treatment with the hair cosmetic, the suitability of the hair cosmetic for the provided hair is evaluated. It is equipped with a process.

According to the present invention, the elastic modulus of the fiber sample can be easily calculated.

FIG. 1 is a schematic diagram showing the configuration of a system for calculating the elastic modulus of a fiber sample. FIG. 2 is a diagram showing an example of the structure of the fiber sample. FIG. 3 is a side view schematically showing a moment of inertia of area specifying device included in a system for calculating the elastic modulus of a fiber sample. FIG. 4 is a cross-sectional view of an example of a fiber sample. FIG. 5 is a perspective view schematically showing a length measuring device included in a system for calculating the elastic modulus of a fiber sample. FIG. 6 is a side view showing a state before applying a load to the fiber sample in the length measuring device. FIG. 7 is a side view showing a state in which a load is applied to the fiber sample in the length measuring device.

FIG. 1 is a diagram schematically showing a calculation system of elastic modulus of a fiber sample (hereinafter, also simply referred to as “calculation system”) in the present embodiment. The calculation system 1 can calculate the elastic modulus of a desired fiber sample. As shown in FIG. 1, the calculation system 1 includes a moment of inertia of area specifying device 10, a length measuring device 20, and a value and length measuring device 20 of the moment of inertia of area specified by the moment of inertia of area specifying device 10. It has an elastic modulus calculation device 30 for calculating the elastic modulus of a fiber sample by receiving the value of the length measured in 1.

The fiber sample from which the elastic modulus is calculated is, for example, mammalian hair, which may have a plurality of layers made of different materials. In the embodiments shown below, the fiber sample is human hair 50. However, not limited to the present embodiment, the fiber sample may be the body hair of a person other than the hair, or may be the body hair of another mammal. Alternatively, the fiber sample may be a fiber sample taken from any fibrous object other than mammalian hair, such as a non-living subject.

FIG. 2 shows a typical hair composition. As shown in FIG. 2, the hair 50 includes a cuticle 51 constituting the surface of the hair 50, a cortex 53 which is a main component inside the hair 50, and a medula 55 extending from the center of the hair 50. Have. However, the boundary between the medula 55 and the cortex 53 is often unclear, and the hair 50 may not have the medura 55. Therefore, in considering the elastic modulus of the hair 50, it is considered that the Medura 55 is integrated with the Cortex 53 for the sake of simplicity below. In other words, the hair 50 is considered to have two layers, namely the cuticle 51 and the cortex 53. The present embodiment can be similarly applied even when the fiber sample such as the hair 50 has three or more layers. That is, even if it is considered that the hair 50 has the cuticle 51, the cortex 53, and the medulla 55, the elastic modulus can be similarly calculated by the elastic modulus calculation system of the fiber sample and the method shown below.

The moment of inertia of area specifying device 10 specifies the moment of inertia of area of the hair 50. The moment of inertia of area specifying device 10 measures the outer diameter of the hair 50 and the thickness of each layer by observing the cross section of the hair 50. The cross section of the hair 50 is, for example, a cut surface exposed by cutting a part of the hair 50, and is observed with a microscope. Therefore, as shown in FIG. 3, the moment of inertia of area specifying device 10 includes a cutting device 11 for cutting the hair 50 and an imaging device 13 for observing the cross section of the hair 50. The cross section of the observed hair 50 is schematically shown in FIG. The cross section of the hair 50 has a substantially elliptical shape. As the outer diameter of the hair 50, the longest major diameter a and the shortest minor diameter b in the cross section of the hair 50 are measured. As the thickness of the layer of the hair 50, the thickness D ₁ of the cuticle 51 in the direction of the major axis of the hair 50 is measured. _The ratio of the thickness D1 of the cuticle 51 to the major axis a of the hair is considered to be substantially constant over the entire cross section of the hair 50.

By considering that the cross section of the hair 50 is elliptical, the moment of inertia of area of each layer can be calculated. Since the outer diameter of the hair 50 and the thickness of each layer can be easily measured, the moment of inertia of area can be easily obtained. The moment of inertia of area specified by the moment of inertia of area 10 is the moment of inertia in the direction most likely to be deformed when a load is applied to the hair 50, that is, the direction in which the moment of inertia of area is the smallest. For example, if the cross section is elliptical, the moment of inertia of area specified is the moment of inertia of area in the minor axis direction. The method of specifying the moment of inertia of area from the outer diameter of the hair 50 and the thickness of each layer will be described in detail in the method of calculating the elastic modulus of the hair 50 described later. The moment of inertia of area specifying device 10 may directly calculate the moment of inertia of area by, for example, analyzing an image of the cross section of the hair 50 without considering the cross section as an ellipse. In this case, the moment of inertia of area specifying device 10 may further include an image analysis device capable of calculating the moment of inertia of area by analyzing the image.

The length measuring device 20 fixes only one end 50a side of the hair 50 and applies a predetermined load to the other end 50b, and then the length between the fixed position of the hair 50 and the other end and the amount of deflection at the other end. To measure. As shown in FIG. 5, for example, the length measuring device 20 includes a fixing base 21 for fixing a part of the hair 50, an image pickup device 23 for taking an image from a direction orthogonal to the longitudinal direction of the hair 50, and the hair 50. It has a load device 25 that applies a predetermined load to the end. In the length measuring device 20, as shown in FIG. 5, the hair 50 is fixed at one end 50a side, but the other end 50b is a free end. At this time, it is preferable that the hair 50 is kept substantially horizontal. The image captured in this state is schematically shown in FIG. A predetermined load is applied to the other end 50b of the hair 50 in the state shown in FIG. When a load is applied to the hair 50, as shown in FIG. 7, a portion of the fixed positions of the hair 50 between the fixed position 50f closest to the other end 50b and the other end 50b bends. The load is sufficiently large enough that the deflection of the other end 50b is observed, and sufficiently small that the deflection of the other end 50b does not exceed the elastic limit. For example, the load is 1 mg weight or more and 2 mg weight or less. The length measuring device 20 measures the length L between the fixed position 50f of the hair 50 and the other end 50b from an image taken with a load applied to the other end 50b. Further, the length measuring device 20 compares the image captured before the other end 50b of the hair 50 is loaded with the image captured after the load is applied, and the length of the other end 50b of the hair 50 is moved. Measure the sa (deflection amount) δ. The length L between the fixed position 50f of the hair 50 and the other end 50b is sufficiently long so that the amount of deflection can be easily observed under a load, and is sufficiently short so as not to be deformed by its own weight. ing. Specifically, the length L between the fixed position 50f of the hair 50 and the other end 50b is, for example, 0.5 mm or more and 2.0 mm or less.

The elastic modulus calculation device 30 receives the values of the moment of inertia of area I of the hair 50, the length L between the fixed position 50f of the hair 50 and the other end 50b, and the amount of deflection δ of the other end 50b. From, the elastic modulus of the hair 50 is calculated. Further, not only the elastic modulus of the entire hair 50, but also the elastic modulus of the cuticle 51 from the moment of inertia of area of each layer of the hair 50, that is, the moment of inertia of area I _cu of the cuticle 51 and the moment of inertia of area I _co of the cortex 53. It is also possible to calculate the elastic _moduli Eco of E _cu and Cortex 53, respectively. A specific method for calculating the elastic modulus of the hair 50 and the elastic modulus of each layer of the hair 50 will be described in detail later.

Next, a method of calculating the elastic modulus of the fiber sample will be described. As an example of the fiber sample, a method for calculating the elastic modulus of mammalian hair having a plurality of layers made of different materials, particularly hair 50 having two layers of cuticle 51 and cortex 53, will be described. The method for calculating the elastic modulus of the fiber sample described below can be similarly applied to any fibrous object other than the body hair of a mammal, for example, a fiber sample collected from a subject other than an organism. ..

First, a plurality of hairs 50 are prepared. These hairs 50 are taken from the same subject. That is, the plurality of prepared hairs 50 are all the hairs of the same person. The number of the prepared hairs 50 is equal to or larger than the number of layers of the hairs 50 (2 in the hairs 50 of the present embodiment). The number of hairs 50 prepared is preferably greater than the number of layers the hairs 50 have. That is, in the present embodiment, three or more hairs 50 collected from the same person are prepared.

Next, the moment of inertia of area of each hair 50 is specified. The moment of inertia of area can be specified by using, for example, the moment of inertia of area specifying device 10. That is, a part of the hair 50 is cut to expose the cut surface, and the cut surface is observed with a microscope. By observing the cross section, the outer diameter of the hair 50 and the thickness of each layer of the hair 50 are measured. The longest major axis a and the shortest minor axis b are measured as the outer diameter of the hair 50, and the thickness D1 of the cuticle 51 in the direction of the major axis of the hair ₅₀ is measured as the thickness of each layer of the hair 50. From these measured values, the moment of inertia of area of the entire hair 50 and the moment of inertia of area of the cuticle 51 and cortex 53 of the hair 50 are specified as follows.

と表される。毛髪５０の断面は、長径をａ、短径をｂとする楕円と考えることができる。この場合、このＩが毛髪５０の短径方向の断面二次モーメントである。 The moment of inertia of area I in the minor axis direction of the fiber sample having an elliptical cross section is based on the assumption that the major axis of the ellipse is a and the minor axis is b.

It is expressed as. The cross section of the hair 50 can be considered as an ellipse having a major axis of a and a minor axis of b. In this case, this I is the moment of inertia of area of the hair 50 in the minor axis direction.

と表すことができる。ただし、Ｄ_０＝０とする。繊維試料の長径ａに対する外側からｎ層目の層の長径の比Ｒ_ｎは繊維試料全体において略一定であると考えられるため、このＲ_ｎを用いると、ｎ層目の層の長径はａＲ_ｎ、短径はｂＲ_ｎと表すことができる。これらを用いると、外側からｎ層目の層の断面二次モーメントＩ_ｎは、

と表すことができる。ただし、Ｒ_Ｎ＋１＝０とする。このことから、毛髪５０のキューティクル５１の断面二次モーメントＩ_ｃｕは、

と表され、毛髪５０のコルテックス５３の断面二次モーメントＩ_ｃｏは、

と表される。ただし、Ｎ＝２であることから、Ｒ_１＝１、Ｒ_２＝１－２Ｄ_１／ａ、Ｒ_３＝０である。 Here, generally, let N be a natural number of 2 or more and n be a natural number of N or less, and consider the moment of inertia of area In of the _nth layer from the outside in the fiber sample having the N layer. The ratio R _n of the major axis of the nth layer from the outside to the major axis a of the fiber sample is

It can be expressed as. However, D ₀ = 0. Since the ratio R _n of the major axis of the nth layer from the outside to the major axis a of the fiber sample is considered to be substantially constant in the entire fiber sample, when this R _n is used, the major axis of the nth layer is aR _n . , The minor axis can be expressed as bR _n . Using these, the moment of inertia of area In of the _nth layer from the outside is

It can be expressed as. However, _{RN + 1} = 0. From this, the moment of inertia of area I _cu of the cuticle 51 of the hair 50 is

The moment of inertia of area I _co of the cortex 53 of the hair 50 is expressed as

It is expressed as. However, since N = 2, R ₁ = 1, R ₂ = 1-2D ₁ / a, and R ₃ = 0.

From the above calculation, the moment of inertia of area I of the hair 50, the moment of inertia of area I _cu of the cuticle 51, and the moment of inertia of area I _co of the cortex 53 are specified by the moment of inertia of area identification device 10.

After that, for each of these hairs 50, the length between the fixed position 50f and the other end 50b of the hair 50 in a state where only one end 50a side of the hair 50 is fixed and a predetermined load P is applied to the other end 50b. The amount of deflection δ of L and the other end 50b is measured. The load P is applied in the direction in which the moment of inertia of area of the hair 50 is small, that is, in the minor axis direction of the hair 50 so that the deflection of the hair 50 can be easily observed. The length L between the fixed position 50f of the hair 50 and the other end 50b and the amount of deflection δ of the other end 50b can be measured using, for example, a length measuring device 20. That is, by comparing the images before and after applying the load to the other end 50b of the hair 50, the length (deflection amount) δ to which the other end 50b of the hair 50 has moved is measured.

Next, the elastic modulus of the entire hair 50 and the elastic modulus of each layer are calculated from the specified moment of inertia of area of each hair 50, the length L from the fixed position 50f to the other end 50b, and the amount of deflection δ of the other end 50b. calculate. The elastic modulus is determined by, for example, inputting the specified moment of inertia of area of each hair 50, the length L from the fixed position 50f to the other end 50b, and the amount of deflection δ of the other end 50b into the elastic modulus calculation device 30. It can be calculated by the rate calculation device 30 performing the following calculation.

と表される。また、図６及び図７に示すような、いわゆる片持ち梁の態様における曲げ剛性ｋは、他端５０ｂにかかる荷重Ｐ、繊維試料としての毛髪５０の固定位置５０ｆから他端５０ｂまでの長さＬ及び他端５０ｂのたわみ量δを用いて、

と表すことができることが知られている。したがって、毛髪５０の断面二次モーメントＩ、他端５０ｂにかかる荷重Ｐ、毛髪５０の固定位置５０ｆから他端５０ｂまでの長さＬ及び他端５０ｂのたわみ量δを測定することで、この曲げ剛性の関係から、毛髪５０の弾性率Ｅを算出することができる。 The elastic modulus can be calculated from the relationship with respect to the flexural rigidity of the fiber sample. The flexural rigidity represents the difficulty of deformation of a linearly extending member such as a beam in a direction non-parallel to the extending direction, and the elastic modulus E of the member and the moment of inertia of area I in the bending direction. Expressed as the product of. That is, the flexural rigidity k of the hair 50 is determined by using the elastic modulus E of the hair 50 and the moment of inertia of area I.

It is expressed as. Further, the bending rigidity k in the aspect of the so-called cantilever as shown in FIGS. 6 and 7 is the load P applied to the other end 50b and the length from the fixed position 50f of the hair 50 as the fiber sample to the other end 50b. Using the deflection amount δ of L and the other end 50b,

It is known that it can be expressed as. Therefore, this bending is performed by measuring the moment of inertia of area I of the hair 50, the load P applied to the other end 50b, the length L from the fixed position 50f of the hair 50 to the other end 50b, and the deflection amount δ of the other end 50b. The elastic modulus E of the hair 50 can be calculated from the relationship of rigidity.

と表すことができる。断面二次モーメントの特定と長さの測定をＮ本以上の繊維試料に対して行うことで、各繊維試料の曲げ剛性と断面二次モーメントとの関係から、各層の弾性率を算出することができる。 When the fiber sample has a plurality of layers, the total flexural rigidity _k of the fiber sample is the sum of the flexural rigidity of each layer, that is, the _sum of the products of the elastic modulus En of each layer and the moment of inertia of area In. .. That is, assuming that the number of layers of the fiber sample is N, the flexural rigidity k of the fiber sample is

It can be expressed as. By specifying the moment of inertia of area and measuring the length of N or more fiber samples, the elastic modulus of each layer can be calculated from the relationship between the flexural rigidity of each fiber sample and the moment of inertia of area. can.

と表すことができる。複数の毛髪５０に亘ってキューティクル５１の弾性率Ｅ_ｃｕ及びコルテックス５３の弾性率Ｅ_ｃｏは略一定であると考えられるため、断面二次モーメントの特定と長さの測定を２本の毛髪５０に対して行うことで、キューティクル５１の弾性率Ｅ_ｃｕとコルテックス５３の弾性率Ｅ_ｃｏとを算出することができる。 The hair 50 has two layers, a cuticle 51 and a cortex 53. Therefore, the flexural rigidity k is

It can be expressed as. Since it is considered that the elastic modulus E _cu of the _cuticle 51 and the elastic modulus Eco of the cortex 53 are substantially constant over a plurality of hairs 50, the moment of inertia of area is specified and the length is measured for the two hairs 50. The elastic modulus E _cu of the _cuticle 51 and the elastic modulus Eco of the cortex 53 can be calculated.

The number of layers of the fiber sample is sufficient for the number of fiber samples for which the moment of inertia of area is specified and the length is measured. In the above description, the elastic modulus of the hair 50 can be calculated by specifying the moment of inertia of area and measuring the length of the two hairs 50. However, by specifying the moment of inertia of area and measuring the length of more fiber samples than the number of layers of the fiber sample, the elastic modulus of each layer can be accurately analyzed by multivariate analysis such as multiple regression analysis. Can be calculated. That is, the geometrical moment of inertia of three or more hairs 50 is specified and the length is measured, the bending rigidity k = E × I of the entire hair 50 is the objective variable, and the geometrical moment of inertia of each layer I _cu , I _co . Is an explanatory variable, the elastic moduli E _cu and Eco of each layer are the regression coefficients, and the _regression coefficients E _cu and _Eco can be calculated accurately by considering it as a multiple regression equation in which the constant term is 0.

The elastic modulus of the fiber sample is one of the factors that determine the texture (flexibility) of the fiber material. Therefore, the feel of the fiber material can be evaluated by calculating the elastic modulus of the fiber sample. Further, in a fiber sample having a plurality of layers, the contribution of each layer of the fiber sample to the touch can be evaluated by calculating the elastic modulus of each layer. For example, by calculating the elastic modulus of the cuticle 51 of a person's hair 50 and the elastic modulus of the cortex 53 and comparing it with the elastic modulus of the cuticle of a general person's hair and the elastic modulus of the cortex, the cuticle 51 and It is possible to evaluate which of the cortex 53 has a smaller contribution to the touch, and further whether the cuticle 51 or the cortex 53 is damaged.

Next, a method for evaluating a treatment agent for a fiber material using such a method for calculating the elastic modulus of a fiber sample will be described. In the following, as an example, an evaluation method of a hair cosmetic for treating hair will be described.

First, the elastic modulus of the hair 50 is calculated by the method described above. Next, the hair 50 is treated with a hair cosmetic. The hair 50 treated with the hair cosmetic is a hair collected from the same subject as the hair 50 for which the elastic modulus was calculated, and preferably the same hair as the hair 50 for which the elastic modulus was calculated. Then, the elastic modulus of the hair 50 after being treated with the hair cosmetic is calculated by the above-mentioned method. The elastic modulus of the hair 50 before being treated with the hair cosmetic is compared with the elastic modulus of the hair 50 after being treated with the hair cosmetic. Hair cosmetics can be evaluated by this comparison. That is, the degree of contribution to the improvement of the feel of the hair cosmetic by the change in the elastic modulus of the hair 50 due to the hair cosmetic, in other words, the change in the texture of the hair 50 by the hair cosmetic, can be evaluated by the change in the elastic modulus. can.

In particular, before and after being treated with hair cosmetics, not only the overall elastic modulus E of the hair 50, but also the elastic modulus E _cu of the _cuticle 51 and the elastic modulus Eco of the cortex 53. It is preferable to calculate. In this case, for each layer of the hair 50, the elastic modulus of the hair 50 before being treated with the hair cosmetic and the elastic modulus of the hair 50 after being treated with the hair cosmetic are compared. The degree of contribution to the improvement of the feel of the hair cosmetic for each layer of the hair 50 can be evaluated by the change in the elastic modulus of each layer due to the hair cosmetic. That is, it is possible to evaluate the contribution of the hair cosmetic to the elastic modulus of the cuticle 51 of the hair 50 and the contribution to the elastic modulus of the cortex 53, respectively.

Next, a method for producing the treatment agent for the fiber material based on the evaluation method for the treatment agent for the fiber material will be described. Hereinafter, as an example, a method for producing a hair cosmetic based on a method for evaluating a hair cosmetic will be described.

From the results of the above-mentioned evaluation of the hair cosmetic, for example, when it is determined that the component for improving the elastic modulus of the cuticle 51 of the hair 50 is insufficient in the hair cosmetic, the elastic modulus of the cuticle 51 is improved in the hair cosmetic. Add ingredients to make. Alternatively, for example, when it is determined that the component for improving the elastic modulus of the cuticle 51 of the hair 50 is excessive in the hair cosmetic, the component for improving the elastic modulus of the cuticle 51 in the hair cosmetic is reduced. In this way, the components of the hair cosmetic are adjusted based on the results of the evaluation method of the hair cosmetic. As a result, it is possible to produce a hair cosmetic having a better feel, in other words, a hair cosmetic having a higher elastic modulus.

Next, a method for determining a treatment agent for a fiber material using such a method for calculating the elastic modulus of a fiber sample will be described. In the following, as an example, a method for determining a hair cosmetic for treating hair will be described.

First, the subject provides the hair 50. The number of hairs 50 provided is preferably plural. Next, the elastic modulus of the provided hair 50 is calculated by the method described above. After that, the hair 50 is treated with a hair cosmetic. The hair 50 treated with the hair cosmetic is preferably the same hair as the hair 50 for which the elastic modulus has been calculated. Then, the elastic modulus of the hair 50 after being treated with the hair cosmetic is calculated by the above-mentioned method. Before being treated with hair cosmetics and after being treated with hair cosmetics, not only the overall elastic modulus E of the hair 50, but also the elastic modulus E _cu of the _cuticle 51 and the elastic modulus Eco of the cortex 53 are calculated. Is preferable. The elastic modulus of the hair 50 before being treated with the hair cosmetic is compared with the elastic modulus of the hair 50 after being treated with the hair cosmetic. This makes it possible to evaluate the contribution of the hair cosmetic used for the treatment to the change in the elastic modulus of the provided hair 50, in other words, the contribution to the change in the texture. That is, it is possible to evaluate the suitability of the hair cosmetic used for the treatment of the provided hair 50. By treating the provided hair 50 with various hair cosmetics, the suitability of each hair cosmetic to the provided hair 50 can be evaluated. Based on this evaluation, the optimal hair cosmetic for the subject's hair 50 can be determined.

The method for determining the hair cosmetic suitable for the hair provided in this way can be used, for example, to receive the hair provided by the customer, determine the hair cosmetic suitable for the hair, and sell the hair cosmetic. can.

By the way, in the method for calculating the elastic modulus of a fiber sample described in Patent Document 1, the elastic modulus of the fiber sample is obtained by measuring the deflection of the fiber sample under a load on the fiber sample many times and measuring a large number of fibers. The elastic modulus of the fiber sample is calculated from the relationship between the load applied to the sample and the deflection of the fiber sample. Therefore, in order to calculate the elastic modulus of the fiber sample, it is necessary to measure many times, which is troublesome. Further, in the method for calculating the elastic modulus of a fiber sample described in Patent Document 2, the cross section of the fiber sample is measured by an atomic force microscope, and the elastic force in each cross section is evaluated by analyzing the cross section. There is. It is not easy to observe the cross section with an atomic force microscope, and it is only possible to evaluate the local elastic force in each cross section, and to evaluate the overall elastic modulus from the local elastic force of the fiber sample. It is difficult. Further, in the method for calculating the elastic modulus of the fiber sample described in Non-Patent Document 2, the outer layer (cuticle) of the hair as the fiber sample is scraped off with a file. Precisely scraping off the outer layer of hair is not easy, time consuming and damages the fiber sample.

On the other hand, according to the method and system for calculating the elastic modulus of the fiber sample of the present embodiment, the elastic modulus of the fiber sample can be calculated by one or several measurements. Moreover, the moment of inertia of area can be easily specified. As described above, in the present embodiment, the elastic modulus of the fiber sample can be easily calculated because the calculation of the elastic modulus of the fiber sample does not require time and effort and does not require precise observation or work.

In addition, according to the method and system for calculating the elastic modulus of the fiber sample of the present embodiment, the elastic modulus of the entire fiber sample can be calculated. Therefore, the feel of the fiber sample as a whole can be evaluated. Further, according to the method for calculating the elastic modulus of the fiber sample of the present embodiment, the elastic modulus of the fiber sample can be calculated without damaging the fiber sample. Therefore, the fiber sample for which the elastic modulus has been calculated can be reused.

Further, in the method and system for calculating the elastic modulus of the fiber sample of the present embodiment, the outer diameter of the fiber sample is measured. The moment of inertia of area of the fiber sample can be easily specified from the outer diameter of the fiber sample. Therefore, the elastic modulus of the fiber sample can be easily calculated. The texture of the fiber sample can be evaluated from the elastic modulus of the fiber sample.

Further, according to the method and system for calculating the elastic modulus of the fiber sample of the present embodiment, when the fiber sample has a plurality of layers made of different materials, the thickness of each layer of the fiber sample is measured. The moment of inertia of area of each layer of the fiber sample can be easily specified from the outer diameter of the fiber sample and the thickness of each layer. Therefore, the elastic modulus of each layer of the fiber sample can be easily calculated. From the elastic modulus of each layer, the contribution of the fiber sample to the texture of each layer can be evaluated.

Further, the number of fiber samples prepared is larger than the number of layers of the fiber samples. By specifying the moment of inertia of area and measuring the length of more fiber samples than the number of layers of the fiber sample, the elastic modulus of each layer can be calculated accurately by multivariate amount analysis. That is, the contribution of each layer of the fiber sample to the touch can be accurately evaluated.

Further, in the hair cosmetic evaluation method of the present embodiment, since the elastic modulus of the hair 50 can be calculated without damaging the hair 50, the elastic modulus of the same hair 50 before and after the treatment of the hair cosmetic is obtained. You can compare the rates. Therefore, it is possible to more appropriately evaluate the change in the elastic modulus of the hair 50 due to the hair cosmetic.

In the method for producing a hair cosmetic according to the present embodiment, the components of the hair cosmetic are adjusted based on the evaluation of such a hair cosmetic. This makes it possible to produce a hair cosmetic product capable of appropriately improving the elastic modulus.

In the method for determining the hair cosmetic of the present embodiment, since the elastic modulus of the hair 50 can be calculated without damaging the hair 50, the elastic modulus of the same hair 50 before and after the treatment of the hair cosmetic is determined. Can be compared. Therefore, the suitability of the hair cosmetic for the hair 50 can be evaluated more appropriately.

As described above, the method for calculating the elastic modulus of the fiber sample of the present embodiment includes a step of specifying the cross-sectional secondary moment of the fiber sample, fixing only one end 50a side of the fiber sample, and a predetermined load on the other end 50b. The step of measuring the length L between the fixed position 50f and the other end 50b of the fiber sample and the amount of deflection δ of the other end 50b, the cross-sectional secondary moment I of the fiber sample, and the fixing of the fiber sample. A step of calculating the elastic modulus of the fiber sample from the length L between the position 50f and the other end 50b and the deflection amount δ of the other end 50b is provided. According to such a method for calculating the elastic modulus of the fiber sample, the length L and the other end between the fixed position 50f and the other end 50b of the fiber sample which are easily specified and the moment of inertia of area and which are easily measured are measured. The elastic modulus of the fiber sample can be calculated from the deflection amount δ of 50b. Since these values can be easily specified or measured, the elastic modulus of the fiber sample can be easily calculated.

Further, the method for calculating the elastic modulus of the fiber sample according to the present embodiment is a method for calculating the elastic modulus of each layer of the fiber sample having a plurality of layers made of different materials, and is a method of calculating the elastic modulus of a plurality of layers collected from the same subject. A step of preparing a fiber sample having a number equal to or larger than the number of layers of the fiber sample, a step of specifying a cross-sectional secondary moment of each layer of each fiber sample, and a step of specifying the fiber sample for each fiber sample. A step of measuring the length L between the fixed position 50f of the fiber sample and the other end 50b and the amount of deflection δ of the other end 50b while fixing only one end 50a side and applying a predetermined load to the other end 50b. , The step of calculating the elastic modulus of each layer of the fiber sample from the cross-sectional secondary moment of each fiber sample, the length L between the fixed position 50f and the other end 50b of the fiber sample, and the deflection amount δ of the other end 50b. To prepare for. According to such a method for calculating the elastic modulus of the fiber sample, the moment of inertia of area of each layer easily identified and the length L between the fixed position 50f and the other end 50b of each fiber sample easily measured are L. The elastic modulus of each layer of the fiber sample can be calculated from the deflection amount δ of the other end 50b. Since these values can be easily specified or measured, the elastic modulus of each layer of the fiber sample can be easily calculated.

It is possible to make various changes to the present embodiment.

For example, in the above-described embodiment, the length (deflection amount) of the other end 50b of the hair 50 is moved by comparing before applying the load P to the other end 50b of the hair 50 and after applying the load P. δ is being measured. However, even if the length (deflection amount) δ of the other end 50b of the hair 50 is measured by comparing the state where the load P1 is applied to the other end 50b of the hair 50 and the state where the load P2 is applied. good. In this case, the bending rigidity k of the hair 50 can be calculated by using the difference between the load P1 and the load P2 instead of the load P.

The hair 50 can be flexed not only by the load applied to the other end 50b but also by the weight of the hair 50 itself. Therefore, when measuring the length (deflection amount) δ of the other end 50b of the hair 50 by comparing before applying the load P to the other end 50b of the hair 50 and after applying the load P, the deflection due to the load P is measured. The sum of the hair 50 and the deflection due to the weight of the hair 50 is measured. Therefore, it is difficult to measure the amount of deflection due to the load P alone. On the other hand, when comparing the state in which the load P1 is applied to the other end 50b of the hair 50 and the state in which the load P2 is applied, the hair is related in relation to the difference between the load P1 and the load P2 and the deflection amount δ of the other end 50b. The influence of the own weight of 50 can be eliminated. Therefore, the relationship between the load and the amount of deflection of the other end 50b can be measured more accurately. That is, the elastic modulus of the hair 50 can be calculated more accurately.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Subject A provided 10 hairs A1 to A10 as fiber samples. For each hair, a part was cut to expose the cut surface, and the cut surface was observed with a microscope (laser microscope VK-X250 manufactured by KEYENCE CORPORATION). From the image of the observed cut surface, the major axis a, the minor axis b, and the cuticle thickness D1 of _each hair were measured. From these values, the moment of inertia of area I of each hair, the moment of inertia of area I _cu of the cuticle, and the moment of inertia of area I _co of cortex were calculated. Then, for each hair, only one end side was fixed, and a load of 1 mg weight was applied to the other end. The amount of deflection δ at the other end was measured by comparing the image captured before applying the load with the image captured after applying the load. In addition, the length L between the fixed position of the hair and the other end was measured. Then, the elastic modulus E of each hair was calculated from these measurement results.

For each hair A1 to A10, the measured hair major axis a, minor axis b, cuticle thickness D ₁ , length L between the fixed position of the hair and the other end, the amount of deflection at the other end δ, and the moment of inertia of area. Table 1 below shows the moment I, the moment of inertia of area I _cu of the cuticle, the moment of inertia of area I _co of the cortex, and the calculated elastic modulus E.

From the results of the moment of inertia of area I of each hair A1 to A10 shown in Table 1, the elastic modulus of the hair E, the moment of inertia of area I _cu of the cuticle, and the moment of inertia of area I _co of the cortex, E × I By _performing multiple regression analysis as = E _cu × I _cu + Eco × I _co , the elastic modulus E _cu of the cuticle and the elastic modulus E _co of the cortex can be calculated. Specifically, E × I is the objective variable, the moment of inertia of area I _cu and I _co are the explanatory variables, the elastic moduli E _cu and _Eco are the regression coefficients, and the constant term is 0. Therefore, the elastic modulus E _cu of the cuticle is calculated to be _15.62 GPa, and the elastic modulus Eco of the cortex is calculated to be 0.86 GPa.

In this way, the elastic modulus of the fiber sample and the elastic modulus of each layer of the fiber sample can be easily calculated.

1 Elastic modulus calculation system of fiber sample 10 Sectional moment of inertia identification device 20 Length measuring device 30 Elastic modulus calculation device 50 Hair 50a One end 50b Other end 50f Fixed position 51 Cuticle 53 Cortex 55 Medura

Claims (12)

The process of specifying the moment of inertia of area of the fiber sample and
A step of measuring the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end while fixing only one end side of the fiber sample and applying a predetermined load to the other end. ,
A fiber comprising a step of calculating the elastic modulus of the fiber sample from the moment of inertia of area of the fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end. How to calculate the elastic modulus of a sample. The method for calculating the elastic modulus of a fiber sample according to claim 1, wherein the step of specifying the moment of inertia of area includes a step of measuring the outer diameter of the fiber sample. It is a method of calculating the elastic modulus of each layer of a fiber sample having a plurality of layers made of different materials.
A step of preparing a plurality of fiber samples collected from the same subject and having a number of fiber samples equal to or larger than the number of layers of the fiber sample.
The process of specifying the moment of inertia of area of each layer of each fiber sample,
For each fiber sample, with only one end side of the fiber sample fixed and a predetermined load applied to the other end, the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end. And the process of measuring
It comprises a step of calculating the elastic modulus of each layer of the fiber sample from the moment of inertia of area of each fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end. Method of calculating elastic modulus of fiber sample. The method for calculating the elastic modulus of a fiber sample according to claim 3, wherein the step of specifying the moment of inertia of area of each layer includes a step of measuring the outer diameter of the fiber sample and the thickness of each layer. The method for calculating the elastic modulus of a fiber sample according to claim 3 or 4, wherein the number of the fiber samples prepared in the step of preparing the fiber samples is larger than the number of layers of the fiber samples. The method for calculating the elastic modulus of a fiber sample according to any one of claims 1 to 5, wherein the fiber sample is the body hair of a mammal. A device that measures the moment of inertia of area of a fiber sample,
A device for measuring the length between the fixed position of the fiber sample and the other end and the amount of deflection of the other end in a state where only one end side of the fiber sample is fixed and a predetermined load is applied to the other end. ,
A fiber comprising a device for calculating the elastic modulus of the fiber sample from the moment of inertia of area of the fiber sample, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end. A system for calculating the elastic modulus of a sample. The device for measuring the moment of inertia of area of the fiber sample is the system for calculating the elastic modulus of the fiber sample according to claim 7, which measures the outer diameter of the fiber sample. The device for calculating the elastic modulus of the fiber sample is the device for calculating the elastic modulus of the fiber sample from the moment of inertia of area for each of the plurality of fiber samples, the length between the fixed position of the fiber sample and the other end, and the amount of deflection of the other end. The elastic modulus calculation system for a fiber sample according to claim 7 or 8, which calculates the elastic modulus of the fiber sample. The step of calculating the elastic modulus of the hair by the method for calculating the elastic modulus of the fiber sample according to any one of claims 1 to 6.
The process of treating the hair with a hair cosmetic and
The step of calculating the elastic modulus of the hair after being treated with the hair cosmetic by the method for calculating the elastic modulus of the fiber sample according to any one of claims 1 to 6.
A method for evaluating a hair cosmetic, comprising a step of comparing the elastic modulus of the hair before being treated with the hair cosmetic and the elastic modulus of the hair after being treated with the hair cosmetic. A method for producing a hair cosmetic, comprising a step of adjusting the components of the hair cosmetic based on the evaluation method for the hair cosmetic according to claim 10. The process of receiving hair donations and
The step of calculating the elastic modulus of the provided hair by the method for calculating the elastic modulus of the fiber sample according to any one of claims 1 to 6.
The process of treating the hair with a hair cosmetic and
The step of calculating the elastic modulus of the hair after being treated with the hair cosmetic by the method for calculating the elastic modulus of the fiber sample according to any one of claims 1 to 6.
From the comparison between the elasticity of the hair before treatment with the hair cosmetic and the elasticity of the hair after treatment with the hair cosmetic, the suitability of the hair cosmetic for the provided hair is evaluated. A process and a method for determining hair cosmetics.

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