JP2003254926A - Measuring method of hair damage degree - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for simply, accurately and easily operating, measuring and deciding the damage degree of hair such as crine, pet hair or wool. <P>SOLUTION: In this method, a prescribed quantity of sampled hair is dipped for a prescribed time in a prescribed quantity of a weakly acidic aqueous solution having a prescribed concentration, and then the conductivity or the conductivity variation of the weakly acidic aqueous solution is measured, to thereby measure the damage degree of the hair, by paying attention to the facts that the heavier the hair damage is, the larger the quantity of ions eluted into the weakly acidic aqueous solution is, to thereby predict the conductivity change in the weakly acidic aqueous solution, and that, on the other hand, with remarkably development progress, a conductivity meter is miniaturized, to have excellent portability and to be inexpensive, enabling recently to measure the conductivity easily with excellent reproducibility only by sampling an extremely small quantity of liquid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to hair, pet hair,
The present invention relates to a method for easily and accurately measuring and determining the degree of damage to hair such as wool.

[0002]

2. Description of the Related Art For example, in the case of performing permanent treatment or hair dyeing on hair, after properly judging the degree of damage to the hair,
It is necessary to select appropriate conditions. However, since the degree of damage to hair and the like has hitherto depended on the appearance and feel of the hair, even a hairdresser requires many years of experience and skill, and the degree of damage that substitutes for such sensory evaluation. Was desired.

Therefore, various methods have heretofore been proposed as methods for measuring the degree of damage to hair or the like. For example, a method of irradiating hair with fluorescent modification and observing it with ultraviolet rays, a method of dissolving hair in an enzyme to measure the weight loss, a method of determining by measuring amino acids in hair, a measurement of tensile strength of hair And a method of directly determining the infrared absorption of the hair, a method of adsorbing a dye on the hair to make the determination, and the like. However, as described above, in any of the methods proposed so far, expensive dedicated equipment is required, complicated operation is required, it is not practical, and there is a problem in measurement accuracy and reproducibility. .

[0004]

SUMMARY OF THE INVENTION In view of the technical problems inherent in the above-mentioned prior art, the present invention is a simple and accurate method for determining the degree of damage to hair such as hair, pet hair, and wool so that anyone can easily operate it. The purpose is to provide a method that enables measurement and judgment.

[0005]

[Means for Solving the Problems] As a result of detailed research on how hair is damaged by permanent treatment of hair or bleaching with hydrogen peroxide solution for dyeing, the surface of hair It became clear that the hair had scratches such as microcracks, and the epidermal layer became thin.When the hair was dipped in a weakly acidic aqueous solution, it was eluted from the hair into the above aqueous solution due to the extent of this damage. The present invention was accomplished by finding that there is a difference in the amount of incoming ions.

That is, the more the hair is damaged, the more the amount of ions eluted in the weakly acidic aqueous solution, and the conductivity of this weakly acidic aqueous solution is expected to change. On the other hand, the progress of development of the conductivity meter is expected. Has been significantly miniaturized, has excellent portability, is cheap, and recently, it has become possible to easily and reproducibly measure its conductivity by sampling a very small amount of liquid. We have found a method for measuring the degree of hair damage by immersing hair in a weak acidic aqueous solution of a predetermined concentration and a predetermined amount for a predetermined time, and then measuring the conductivity or the amount of change in conductivity of the weak acidic aqueous solution.

Here, the reason why the weakly acidic aqueous solution is used is that the electric conductivity is changed by the ions eluted from the hair, and the electric conductivity is required to be relatively small so that the change can be measured. Therefore, the type of aqueous solution is not particularly limited as long as it meets the above purpose, but anyone can easily obtain, easy to handle and excellent in safety, acetic acid aqueous solution using vinegar, citric acid Aqueous solutions are a typical example. In addition, boric acid, oxalic acid, tartaric acid, etc. may be used.

In addition, "measuring the conductivity or the change amount of the conductivity" is not limited to the measurement of the conductivity.
If the concentration of the weak acid aqueous solution is adjusted to a constant value, a predetermined amount of hair is sampled and immersed in a predetermined amount of liquid, and the conductivity after temperature correction is measured. It is possible to measure and judge the degree of damage to the hair by comparing the conductivity of the hair with the degree of conductivity, but if the amount of hair to be sampled is not constant or there is a possibility that the concentration of the weak acid aqueous solution may change, a hair test is performed. The conductivity before dipping the sample is measured, then the hair is dipped, the conductivity after a predetermined time is measured, and the change amount of the conductivity before and after that is obtained to obtain the relationship between the test liquid amount and the hair amount. This is because it is possible to obtain the degree of damage from a comparison table or comparison graph with the previously obtained amount of change in conductivity.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hair damage occurs, for example, when hair is subjected to permanent treatment, hair dyeing treatment, and bleaching treatment, but also when exposed to ultraviolet rays of sunlight, disturbance of lifestyle, stress, etc. Occurs. Therefore,
Hair damage measurements should be evaluated comprehensively. Hereinafter, an example in which an aqueous solution of acetic acid is used will be described as a preferred embodiment of the present invention, but the type, concentration, etc. of the aqueous solution are selected according to the importance of the various damage factors.

The graph shown in FIG. 1 shows the results of an investigation of the relationship between the bleaching frequency for hair and the conductivity of an acetic acid aqueous solution. As acetic acid aqueous solution for dipping hair, vinegar having a concentration of about 5% was used, 20 mg of hair was sampled and dipped in 500 μl of an aqueous solution adjusted to pH = 3, and the conductivity was measured after standing for several minutes. . As a result, the conductivity increases almost in proportion to the number of permanent treatments increasing from 1 to 6. Also, in the case of bleaching, the number of times has increased according to the number of times of processing.

In the graph shown in FIG. 2, it is assumed that the number of times permanent treatment is performed is one and the degree of damage is high.
This is a test evaluation of how the conductivity changes with changes in the number of bleaching treatments. As a result, even those with one permanent count have 6
It was also found that the conductivity of the one having the number of times increased as the number of bleaching. Therefore, from the investigation results shown in the graphs of FIG. 1 and FIG. 2, it has been clarified that each damage degree can be quantified as the conductivity in accordance with the number of permanent treatments and the number of bleaching treatments.

In the above example, the pH of the acetic acid aqueous solution was set to 3 to 500 μl because the recent portable small-type conductivity meter can sufficiently measure this amount. Therefore, the amount and concentration of the test solution should be adjusted according to the specifications of the conductivity meter. Further, in the case of the present embodiment, the hair sampling amount can be sufficiently measured in the range of about 10 to 50 mg, but this can also be freely adjusted according to the specifications of the conductivity meter and the amount and concentration of the test solution. Is.

[0013]

INDUSTRIAL APPLICABILITY In the present invention, a small conductivity meter that is widely available on the market is used, and a weak acid aqueous solution with vinegar or the like that is safe to handle and easily available is used. In addition, the degree of hair damage can be measured and judged with good reproducibility in a short time.

[Brief description of drawings]

FIG. 1 shows the results of an investigation of the change in conductivity with the number of bleaching treatments for hair.

FIG. 2 shows the results of investigation of the change in conductivity when the number of permanent hair treatments is fixed and the number of bleach treatments is changed.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Eiichi Mintani             3-17-14 Heiwacho Kanazawa, Ishikawa Prefecture Heiwa Dormitory             C58 Building No.13 F term (reference) 2G045 AA40 BA11 BB31 CB16 FB05                       GC16 JA01                 2G060 AA06 AD06 AD09 AE26 AE40                       AF08 KA09

Claims (2)

[Claims] 1. A degree of damage to hair is measured by immersing a hair sampled in a predetermined amount in a weak acidic aqueous solution having a predetermined concentration and a predetermined amount for a predetermined time, and measuring the conductivity or the amount of change in conductivity of the weak acidic aqueous solution. How to measure. 2. A method for measuring hair damage, wherein the weakly acidic aqueous solution according to claim 1 is an aqueous solution of acetic acid or citric acid.