JPS63150006A - Method for evaluating effect of hair styling product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for evaluating the effectiveness of hair styling products.

BACKGROUND OF THE INVENTION Hair stylists apply various compositions to a person's hair to help it retain its setting when styling is complete. Different compositions have different abilities to hold set, and different compositions are used on different types of hair to achieve the desired effect.

No satisfactory quantitative technique has yet been developed to measure the "retention factor" or ability of a composition to hold styling when used in a salon.

The most satisfactory techniques rely on the skill and experience of the operator to sense the effects of the composition when the styling is completed.

Although this is sufficient for workers to know that the desired effect has been obtained by setting the setting in the salon, it is not quantitatively sufficient for developing new products, and it is not quantitatively sufficient for developing new products. This is a cumbersome method for comparison. Furthermore, comparative studies are almost impossible due to the variable nature of hair and the lack of controls.

Although various test methods have been tried, none have been sufficient to determine the retention efficacy of various compositions. For example, tensile tests on strands or mm of hair do not correlate well with salon setting results. Therefore, it would be desirable to provide a simple, reliable, and reproducible method for testing the retention capacity of various compositions.

SUMMARY OF THE INVENTION In a preferred embodiment, the present invention curls hair tresses treated with such styling products and measures the work due to deformation of the curled hair tresses. The deformation work of a curled hair tress is compared to the deformation work of a hair tress simply treated with water. This offsets the effects of water and evaluates the effectiveness of the styling product itself.

The same hair sample is used for both tests to serve as a control for comparison. In a preferred embodiment, (a)
(b) the sum of the products of the force required to deflect a hair loop treated with a hair styling product and the deflection distance of the treated hair loop; (b) required to deflect a hair loop treated with water; Determine the ratio of the sum of the products of the force and the deflection distance of the water-treated hair loop.

DETAILED DESCRIPTION It is well known that hair is saturated or partially soaked with water, curled or set into a desired style, and remains set when drying. It is understood that when hair is set with water, the hydrogen bond structure of the keratin protein that forms the hair is reorganized, thereby making it possible to maintain the set.

Also, various chemical treatments, perms and reactive procedures in the salon are carried out. These are understood to reconstitute the ionic or covalent structure of the proteins that form the hair. These effects are superimposed on the effects of structural rearrangement due to hydrogen bonding.

Additionally, there are interactions between hair fibers that affect the hair's ability to hold set. There are FJ rubs of the inner fibers that are modified by various substances such as resin fibers and the like that are applied to the hair. For example, microscopic examination of hair spray-treated hair shows that adjacent fibers have an increased tendency to interact, or that there are "partial bonds" of internal fibrils that act as pads or supports that hold many fibers together. Or ``coated products'' can be seen. These effects are also superimposed on retention by water alone.

In evaluating compositions that are applied to hair for the purpose of modifying the hair's ionic or covalent bonds or altering the internal strands, it is desirable to counteract the water retention effect.

It is clear that human hair is highly individual and different types of hair have different properties. The difference is largely due to the natural properties of the hair. It can also be caused by chemical treatments that have already been applied. For example, bleached hair behaves differently than unbleached hair. Therefore, controls need to be performed using the same hair sample as well as the substance to be tested, even to offset the effects of water contributing to hair set.

In the method of carrying out the invention, a hair tress weighing 0.5 g is used. Visually, the hair bundle was approximately 21 cm long, including some lengths and short lengths, which is commonly used as a hair sample. Each test of a styling composition is compared to a control using the same hair tress. Each test and control is preferably performed three times to minimize the effects of variation and clearly exclude outlier data, so six hair tresses are used and a total of 3 g of hair sample is required.

Each hair tress is tied together with a stainless steel band about 2 CI 11 from the end. Prepare the tied hair tresses for testing by washing them with a washing solution, rinsing them thoroughly and drying them thoroughly at room temperature.

Place the hair tresses in water for about 30 minutes at room temperature to infiltrate them.

Next, the outer diameter 2.8C1m used in the salon shown in Figure 1
The plastic hair styling roller 10 is manually wrapped around the plastic hair styling roller 10 like a ribbon. The end of the hair 11 with the catch 12 is placed against the roller 10 and the ribbon of hair is wrapped around the roller 10 so as to cover the clipped end. It is preferred to have slightly more than two complete wraps around the roller. The curled hair strand is held using a conventional salon clip 13 shown in FIG.

The hair bundle, which has been curled and secured with clips 13, is dried on rollers at 50° C. for 1 hour in an oven designed to generate air convection in order to sufficiently dry the hair bundle. All hair samples are wound around rollers in exactly the same manner as the water-soaked comparison samples.

To evaluate the effectiveness of various ingredients such as resins or finishing styling formulations, water-soaked hair tresses are treated with a set of test substances. Preferably about 0.5g on each tress both before and after winding the tress on the rollers.
Apply the test substance. For example, the test composition can be up to 1% by weight polyvinylpyrrolidone in water. 0.5 ml of the aqueous solution is pipetted around the wound hair tress on the roller.

Based on a given test procedure, six substantially identical hair tresses are treated in this manner. 8 water! Three moistened hair tresses are rolled and dried to serve as a control. Three tresses treated with the test composition are rolled and dried in a similar manner. In this way, six hair curve samples or hair loops are obtained whose inner diameter is the same as the outer diameter of the plastic roller.

The work of deformation of the hair loops is measured by compression tests. The test machine measures the force required to deform a hair loop as a function of distance. The product of force and distance is a measure of the work required to deform the hair loop. A standard Instron tension tester can be used for this purpose.

The hair sample 11 is placed upright on the lower stand 14 of the tester with the band at one end of the hair bundle at the bottom. A small piece of transparent tape 15 or the like is passed through the hair loop and secured so that the hair loop is held upright as shown in FIG. The movable head 16 of the tester is then lowered against the hair loop, applying force to change the curled hair from its original circular cross-section to an oval cross-section.

The force is increased at a constant rate until a predetermined deflection magnitude is reached, at which point the force and deflection are released.

A typical test involves deforming a hair loop such that the short axis of the deformed loop is approximately half the diameter of the original circular loop. In one test all 6 hairs are tested to the same proportion and to the same maximum value.

Deflections and forces are recorded on a band chart recorder to obtain stress strain curves such as the representative example shown in FIG. The illustrated curve represents the case of relatively stiff hair; a more flexible tress will have a lower slope with increasing force. The work done to deform the test sample is proportional to the area under this curve. This area is integrated to obtain the work. This can be done using a planimeter, or by cutting out the area surrounded by the curve with scissors from the band chart and weighing it, as is conventional practice. 11 is proportional to the area under the stress strain curve, which area is proportional to the work required to push down the hair loop. The deformation work determined by the three control tests as well as the results of three tests of hair treated with the composition to be evaluated are averaged. The "retention factor" is calculated by determining the ratio of the average work of compression of three samples treated with the styling composition to three control samples treated with water alone. The ratio of the work required to compress the treated sample to the work required to compress the sample effectively offsets the setting effect due to water.

The retention factor, or the ratio of work required to deform two samples, is a good measure in a salon environment of the ability to retain a set of styling compositions. Retention factors generally range from about 2 to about 20. That is, the work done in deforming a treated sample is 2 to 20 times the work done in deforming a similar sample treated with water alone.

Retention factors as high as 40 were also observed. Some cosmetic products have retention factors as high as 30 in this test;
Most commercial products have retention factors of up to about 20.

Tests were confirmed on various compositions. - For example, 0
．． Polyvinylpyrrolidone (PVP) aqueous solutions of 2511ffi%, 0.5% by weight, 0.75% by weight and 1.0% by weight were tested. The retention factor increased linearly to a retention factor of 4 as the PVP 11 degrees increased to approximately 1 fold ω%.

In other test groups, retention factors due to other common ingredients of hair styling compositions were determined. sr up to 1.5% by weight! 1 PvP/vAE aqueous solution-1 PVP/
VAE is a copolymer of PVP and vinyl acetate. The retention factor increased linearly until the retention factor was approximately 1.4 at the highest concentration.

Complex mixtures with various solvents, polymers, and other additives can modify the interaction of the hair with the resin, and it is desirable to conduct tests in these mixtures even though the retention factors of the individual components are known.

For example, 1 ml of A mersette, which is often used exclusively as a hair styling ingredient.
．． 5-3. A styling mousse is prepared using a concentration of % own. The retention factor increases linearly with increasing concentration of this complex mixture.

This test shows good reproducibility for one substance on different hairs. Analyzing 26 control tests of 3 pieces each set in water, the average deviation was approximately 1.
It was 0%. 3 each similarly treated with various products.
When 80 tests were analyzed, the average deviation was about 14%.

The change in work of deformation measurements tends to increase with increasing composition resulting in harder test samples. That is, a high retention factor increases the deviation, typically by 20%.
It is as follows. It is believed that the increased deviation is due to increased sensitivity to changes when applying the composition to the hair tress. If greater precision is required, the certainty of the test results can be increased by increasing the number of test samples and testing and averaging other hair samples. This is desirable, for example, when using styling foams where fluctuations of as much as 25% are sometimes observed. The variation in retention factors observed with commercial products may be the result of non-uniform distribution of the foam agent or the use of highly tacky products on the hair prior to loop formation and drying.

The hair loop test, which measures the work used to compress a hair loop, correlates well with the hair stylist's tactile perception. Stylists generally evaluate the ability of hair to hold hair set by the feel of the styled hair. Experienced workers evaluate the degree of crunch by pressing the hair.

The measurement of deformation work by the aforementioned tests cannot provide any sensitivity even for skilled workers. For example, it is almost impossible for a skilled operator to distinguish between compositions with a retention factor of 6 to 8, whereas the test according to the invention easily distinguishes between these compositions. therefore,
This test can mimic to some extent what is done with a styling mousse when the operator crunches the hair. However, this test is substantially more sensitive than subjective tests by salon workers. Measuring the deformation work of curled hair by offsetting the setting effects of water provides an excellent objective method for evaluating existing cosmetic compositions and new compositions being developed for the styling market. be. It is much faster and cheaper than testing new compositions in a dedicated field.

It will be clear that the methods for evaluating hair styling products obtained by practicing the present invention are susceptible to various modifications or variations. Although the above examples have been described with selected weights and lengths of hair, and selected concentrations of test substances, it is clear that these values can be modified as appropriate for a particular implementation. . What is required is that the hair used in the control be similar to the hair used in a given test.

If desired, instead of a water-only control, a control with an additional reactive treatment can be used to better assess the effectiveness of the combined treatment with the composite composition.

Instead of directly measuring the area under the curve of a stress-strain curve to measure the work of deformation, if the measured line is approximately linear, simply measure the slope of this line, which represents increasing force as a function of displacement. You can also. Similarly, products with comparative values corresponding to a given force or a given deflection can also be used as a measure of work hardness if the deformation is approximately linear. In other words, when the stress-strain diagram is linear, the deformation work compares to the elastic module of curl deformation. Integrating the area under the curve is a highly preferred method as it is an easy way to quantify the nonlinear curves that occur in the case of bonded samples in the practice of the present invention.

The tests were conducted in an air-conditioned laboratory, and the control and test samples were all compression tested in a relatively short period of time, so there was little variation due to the ambient conditions at the time of the test. If desired, the treated hair loop test and the untreated hair loop control can be alternated to minimize the effects of changing conditions.

Similarly, if desired, testing can be conducted in an environmentally controlled room with constant humidity and temperature. However, this improvement was not necessary in normal testing. If it is desired to test the effectiveness of a substance in imparting droop resistance to hair, tests can be carried out at various humidity levels.

It will be clear to those skilled in the art that the test method for comparing the deformation work of a treated hair tress with the deformation work of a control in order to evaluate the effectiveness of hair styling products is capable of various IiMs and modifications. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a stage in which a hair bundle is wound around a roller to form a loop in order to carry out the evaluation method according to the present invention, and Fig. 2 is a perspective view showing a stage in which a hair bundle is wound onto a roller to form a loop for drying. FIG. 3 is a perspective view showing a wound hair bundle, FIG. 3 is a view showing a compression test of the hair loop, and FIG. 4 is a view showing a typical stress-strain curve obtained in the compression test. 10... Roller 11... Hair 12... Stopper
13...Clip patent applicant Redken Laboratories. Incoholated

Claims (17)

[Claims] (1) forming a curled hair tress treated with a hair styling product; measuring the work of deformation of the treated curly hair tress; A method for evaluating the effectiveness of a hair styling product, comprising the steps of deforming a hair bundle and comparing it. (2) The step of forming a rolled hair bundle comprises soaking the hair bundle with water, winding the hair bundle around a cylinder, and drying the hair bundle on the cylinder. (1
Evaluation method described in section ). (3) Claim No. 2 in which the hair bundle is wound around the cylindrical body and then the rolled hair bundle is treated with a hair styling product.
Evaluation method described in section ). (4) The evaluation method according to claim (2), wherein the water-treated rolled hair bundle is formed in the same manner as the rolled hair bundle. (5) The evaluation method according to claim (1), wherein the deformation work is measured by compressing the diameter of the wound hair bundle. (6) The evaluation method according to claim (5), wherein the deformation work is the product of the amount of deflection of the wound hair bundle and the force used to deflect the wound hair bundle. (7) The comparison step includes the deformation work of the rolled hair bundle;
4. Evaluation method according to claim 3, comprising determining the retention factor, which is the ratio of the work of deformation of the wound hair tress treated with water to the work of deformation. (8) The comparison step includes the deformation work of the rolled hair bundle;
Evaluation method according to claim 1, which comprises determining the retention factor, which is the ratio of the work of deformation of the wound hair tress treated with water to the work of deformation. (9) The treating step comprises determining the ratio of the area under the stress-strain curve of the rolled hair tress to the area under the stress-strain curve of the rolled hair tress treated with water. Scope of the evaluation method described in paragraph (1). (10) The evaluation method according to claim 9, wherein the stress-strain curve is obtained by compressing the wound hair bundle in the radial direction. (11) soaking at least one pair of identical hair strands in water; wrapping each hair strand around a cylinder to form a hair loop; and applying at least one of the hair strands to a hair styling substance. drying said hair loops; radially compressing each hair loop; The method of claim 1, comprising the step of comparing at least one of the treated hair loops with at least one other hair loop. (12) the comparing step comprises: (a) finding the product of deformation force and deformation distance for at least one of the treated hair loops; and (b) deformation force for at least one of the other hair loops. and the deformation distance; and further, determining the ratio of the products obtained in steps (a) and (b) above. Law. (13) forming a hair tress treated with a hair styling product into a loop; drying the treated hair loop; radially compressing the treated hair loop; and bending the treated hair loop. summing the product of the force required to hold the hair loop and the deflection distance of the treated hair loop; forming the same wetted hair strand into a loop; and drying the wet hair loop. radially compressing the wet and dry hair loop; a force required to deflect the wet and dry hair loop; and a deflection distance of the wet and dry hair loop. The evaluation method according to claim 1, comprising the steps of: summing the products of the two summing steps; and determining a ratio of the values obtained in the two summing steps. (14) treating the hair tress with a hair styling substance; winding the hair tress around a cylinder to form a wound hair tress; drying the wound hair tress; 1. A method for evaluating the retention ability of a hair styling substance, comprising: radially compressing a wound hair bundle; and measuring compression resistance of the treated wound hair bundle. (15) The evaluation method according to claim (14), wherein the hair bundle is treated with a hair styling substance before being wound around the cylindrical body. (16) The evaluation method according to claim (14), wherein the measuring step comprises measuring the area under the stress-strain curve of the treated hair loop. (17) The evaluation method according to claim (14), wherein the measuring step comprises measuring the deformation work of the treated hair loop.