Kit and method for determining the level of hair damage

Abstract

The present patent of invention belongs to the technical field of material analysis for determining chemical properties and it is characterized by comprising a kit for determining the level of hair damage, including a reagent to be used and a reference scale containing a defined damage scale. Furthermore, the present patent also provides a method for using the kit, comprising the following steps: (i) determining Einitial (indicating the color value in the CIELAB space) of the hair sample using a spectrophotometer, for example, before performing desired hair treatments such as bleaching, blow-drying, coloring, among others; (ii) submerging the sample, for example, after the desired treatments, in copper sulfate present in the kit for one to three minutes; (iii) determining, using the spectrophotometer, the Efinal of the sample after reaction with the reagent; (iv) calculating delta E (Einitial − Efinal); and (v) comparing the result with the reference damage scale that forms part of the kit and defines at least three levels of damage.

Description

"KIT AND METHOD FOR DETERMINING THE LEVEL OF HAIR DAMAGE"

[0001] This invention patent belongs to the technical field of materials analysis for the determination of their chemical properties, characterized by comprising a kit and method for determining the level of hair damage. More specifically, it presents a kit composed of a reagent that alters the color of the hair sample and allows the determination of the degree of damage by colorimetric techniques correlating to a ruler with a determined damage scale, also present in the kit, in addition to revealing the method for its respective use. Thus, this patent presents a solution to identify the damage caused by bleaching, straightening, and other procedures, and thus enable the definition of the best treatment to restore the health of the hair fiber by the user and / or professional in the field. STATE OF THE ART

[0002] Patent documents found in the prior art that present the use of reagents and colorimetry techniques to measure the level of hair damage exhibit different forms of application and operation when compared to the subject matter of this invention patent.

[0003] For example, document JP2002107362 reveals a quick and simple method for diagnosing the level of hair damage using cupric salts, which is based on measuring the amount of protein eluted from the hair, and considers this result directly proportional to the degree of damage. It is possible to diagnose the color change of the copper complex by comparison with previously prepared standard samples, but if a more rigorous diagnosis is desired, spectrophotometers can be used.

[0004] Document US7749763 presents a kit and method for determining the amount of hair damage based on metal sorption by hair after immersion in a solution containing at least one metal ion. The patent also reveals a scale correlating the amount of hair damage with the amount of metal bound to the hair.

[0005] Document JP2005287853 presents a non-invasive and quantitative method. capable of identifying the type of chemical substance that caused the damage, as well as the extent of the damage. This document presents an index developed from statistical processing of data obtained from measuring infrared light absorption spectra, without the use of reagents.

[0006] Document US4510250 describes a method for measuring hair damage based on quantifying the color intensity of the copper reaction complex with a specific amount of hair, and also presents an instrument for determining the sample weight / volume. The reaction of copper with hair occurs by heating the tube, and then the sorption of copper by the hair is measured. This measurement can be made by comparing this flask after the reaction with several other flasks containing the same solution with different copper concentrations in each, like a scale, or electronically, using a spectrophotometer. TECHNICAL PROBLEM

[0007] Although the state of the art foresees the use of metallic salts and colorimetric equipment to measure the level of hair damage, no documents were found that present the use of only copper sulfate for hair coloring linked to spectrophotometer reading to then correlate this value with a damage level scale. In the methods already known, the results are based on the elution or sorption of the reagent by the hair or purely on the color change of the solution obtained, that is, they are based on indirect data and the level of damage is estimated in relation to the intensity of the color.

[0008] Document JP2002107362, for example, uses a set of reagents, which may include copper salts, promoting the elution of proteins from the hair strand, resulting in a change in the solution's color. The intensity and / or shade of the color developed in the reagent indicates the level of damage suffered by the hair, and the result is visually defined.

[0009] Although it mentions various types of metallic salts to enable the determination of hair damage, including copper salts, document US7749763 does not recommend it for this diagnosis, arguing that the natural presence of this Copper ions in hair can distort the results. Given that the method involves determining the concentration of ions eluted from the sample and may remove copper ions initially present, the result would indeed be altered.

[0010] Document JP2005287853 describes a method based on infrared spectral analysis and statistical processing. To enable a diagnosis, a database is needed, which would require a minimum number of samples to build a reliable model.

[0011] The method proposed in document US4510250, for evaluating hair damage, relies on measuring the volume of a hair sample and its reaction with a copper sulfate and ethanolamide solution in boiling water to allow for the assessment of the resulting color intensity. This method presents challenges, given its aim for easy application in non-laboratory settings.

[0012] Thus, although the state of the art provides methods for determining hair damage using colorimetry, direct correlations with the level of damage or how to define them are not presented. Therefore, a more refined solution is still needed that uses a method simple enough to be reproduced in beauty salons and that maintains the reliability of the result, regardless of the interaction of the reagent with the ions and proteins in the hair sample. TECHNICAL SOLUTION

[0013] With the aim of making the diagnosis of the degree of hair damage technically and economically viable in order to present sensitive, direct and objective results in non-laboratory environments, the present kit and method for determining the level of hair damage were developed.

[0014] The methodology proposed here is based on the reaction of hair with copper sulfate and the reading of the sample with a spectrophotometer, and correlation of the result obtained with the proprietary damage scale.

[0015] To perform the hair damage diagnosis using the presented methodology, the kit consisting of the reagent and the constructed and validated ruler with the damage scale is required.

[0016] The use of the hair diagnostic kit and method can be applied in beauty salons or at home by hairdressers, generating quick and sufficient information to propose a hair treatment schedule that is much more targeted to the level of damage, generating more satisfactory results for clients. BRIEF DESCRIPTION OF THE FIGURES

[0017] The description that follows is not limited to the drawings or components mentioned, and refers to the illustrations referenced below.

[0018] Figure 1 presents the color diagram as defined by the International Commission on Illumination (CIELAB scale).

[0019] Figures 2A, 2B, 2C, and 2D present the graphs from the second test with treatments A, B, C, and D. Mean values ​​of delta a* at different concentrations of copper sulfate (0.05%, 0.07%, 0.08%, 0.09%, and 0.10%) and different times (1, 2, and 3 minutes).

[0020] Figure 3 shows the hair strands after the different chemical treatments, from left to right: strand G (one bleaching), strand H (two bleachings), strand I (three bleachings), strand J (one straightening and one bleaching), and strand K (one straightening and two bleachings).

[0021] Figure 4 shows how the ends of the hair strands looked after the reaction with 0.08% copper sulfate for 3 minutes of the remaining treatments, from left to right: strand E (no damage), strand F (comb and hair straightener), strand G (one bleaching), strand II (two bleachings), strand J (one straightening and one bleaching), strand L (one bleaching and one coloring), and strand M (one coloring). DETAILED DESCRIPTION

[0022] When hair undergoes chemical treatments such as coloring, bleaching, or other treatments that alter the hair structure, the cuticle, which is the outermost structure, tends to suffer damage and, consequently, presents more carboxylated and sulfonated groups (present as cysteic acid) that are formed by the oxidative cleavage of peptide bonds and disulfide bridges.

[0023] The presence of these negative charges on the surface means that these hair fibers are more capable of binding with metallic salts, and explains why hair damage is proportional to the amount of ion binding.

[0024] When using a copper sulfate and water solution as the preferred solvent, this ion is deposited in the cortex layer of the hair strand, altering its color, since copper(II) ions can bind to any isolated electron (for example, in nitrogen or sulfur atoms) or to negative charges present on the hair surface. Therefore, damaged hair is more susceptible to color change; that is, the more damaged the hair fiber, the greater the color difference.

[0025] This color difference can be measured by a spectrophotometer, using the CIELAB scale, developed by the International Commission on Illumination, considered the authority in the science of light and color, for the communication and expression of colors. Color corresponds to a point in the space of the chromaticity diagram, which consequently presents its coordinates L*a*b* (Figure 1). The spectrophotometer measures and quantifies these color attributes, presenting the information in numerical terms.

[0026] Color differences are defined by a numerical comparison between the sample and the standard. This indicates the absolute differences in color coordinates, known as deltas (A). Deltas for IA (AL) indicate the difference between light and dark, a* (Aa) indicates the difference between red and green, and eb* (Ab) indicates the difference between yellow and blue. Delta E (AE) indicates how much the color varied in the color space. Through these coordinates, it's also possible to determine if the color became lighter or darker, more red or green, or more yellow or blue.

[0027] To achieve a color change in the sample, a metallic salt solution is needed to bind to the negative charges present on the hair surface. Furthermore, it must have low or no toxicity so that chemical technicians or those with similar training are not required to perform the method, and it effectively allows for color identification. Based on these points, a copper sulfate solution was chosen as the reagent.

[0028] To develop the methodology for diagnosing hair damage and the proprietary damage scale, using copper sulfate reagent along with colorimetry techniques, a series of tests were conducted to investigate possible interferences during the methodology. The first tests were performed with three hair strands from different batches (A, B, and C) to verify the spectrophotometer readings, using different reading backgrounds: a white towel, a ceramic screen, the palm of the hand, and a hair strand support rack.

[0029] Analysis of variance (ANOVA) was used to analyze the differences between the means of two or more groups. From the statistical analysis, the sum of squares (SS), degrees of freedom (df), mean squares (MS), F-value, and P-value were obtained for each of the test repetitions (A, B, and C). The statistical analysis presented a 95% confidence interval, and it was possible to conclude that there was no significant difference (P-value > 0.05) between the readings with different backgrounds (F < Fcritical), as presented in Tables 1, 2, and 3, corresponding to the analyses for strands A, B, and C, respectively, with a significance level of 5%.

[0030] Therefore, the same reading performed in a laboratory can be reproduced by a professional in a beauty salon by reading a strand of hair on a white towel or the palm of the hand. Table 1 GROUP COUNT SUM AVERAGE VARIANCE Partition 3 9.17 3.056666667 0.086233333 Towel 8.2.1 2.736666667 0.012033333 Hand 3 9.08 3.026666667 0.156433333 Clothesline 3 9.22 3.073333333 0.034533333 Fountain of SQ gl MQ F Critical value~PF variation Between 1.04828857 0.422609379 4.06618055 0.2274 A 0.0758 groups 9 Within 0.072308333 0.5784666667 8 - out of 33 groups Total 0.8058666667 11 Table 2 GROUP COUNT SUM AVERAGE VARIANCE Partition 3 8.54 2.846666667 0.03363333333 Towel 3 8.98 2.993333333 0.02083333333 Hand 3 8.74 2.913333333 0.03403333333 Clothesline 9.44 3.146666667 0.07583333333 Fountain of SQ gl MQ F Value-P F critical variation Between 0.05007777 1.21893171 4.066180 0.1502333333 3 0.3640089631 groups 778 1 551 Inside 0.04108333 of 0.3286666667 8 333 groups Total 0.4789 11 - - Table 3 GROUP COUNT SUM AVERAGE VARIANCE Partition A 6.82 2.27333333 0.0433333333 Towel 3 6.17 2.05666667 0.2358333333 Hand 3 6.66 2.22 0.0804 V arai 3 7,23 2,41 0,0268 Source of SQ gl MQ F Value-P F critical variation Between 0.064022222 0.66281310 4.066180 0.1920666667 3 0.5978071095 groups 22 21 551 Inside 0.096591666 of 0.7727333333 8 67 groups Total 0.9648 11 - - -

[0031] With the validation of the equipment readings and the defined reagent, it was already possible to define part of the method to be used.

[0032] A second test was conducted to optimize solution concentration parameters and reaction time. During the study developed to diagnose the degree of hair damage, the procedure involves immersing a portion of the damaged hair strand in a copper sulfate solution, where a color change occurs in that hair strand, proportional to the damage and integrity of the hair fiber. The evaluation group consisted of different treatments; however, strands from the same batch, approximately 20 cm long and weighing an average of 5.0 ± 0.5 g, were prepared according to the Hair Strand Washing Protocol that would be known to a technician in the field – Consumer Science.

[0033] Three treatments were performed that combined mechanical, chemical, and temperature damage. Treatment A is the standard, no-damage treatment, where hair strands were simply washed according to protocol and hung on a clothesline to dry at room temperature. Treatment B combined washing the hair strand, followed by 10 minutes in a styling device and 20 passes with a hair straightener at 230°C. Finally, the hair strand was washed again using the same protocol and hung on a clothesline to dry at room temperature. Treatment C involves two sequential bleaching processes. After washing and drying with heat for 2 minutes, the hair strand was left to rest for 1 minute on aluminum foil where a bleaching product (e.g., a mixture of Truss Air. Libre bleaching powder and Truss Creme Developer - 40 Vol Oxidant) was applied according to the manufacturer's protocol, and left to react at room temperature for 1 hour.After this period, the hair strand was washed according to the washing and drying protocol, and then this entire process was repeated. For treatment D, after washing the hair strand, it was hot-dried for 2 minutes and left to rest for 1 minute. Then, with the hair strand held on a clothesline, a straightening product, for example, Wella Professional Wellastrate Intense Straightening Cream, was applied according to the manufacturer's protocol and reacted at room temperature for 25 minutes. Afterwards, the hair strand was washed with warm water until the product was removed, hot-dried, and ironed. The hair was straightened 10 times at 230°C, then a neutralizer (e.g., Neutralizing Lotion, Wella Professionals Wellastrate) was applied according to the manufacturer's protocol, acting at room temperature for 15 minutes. Next, the hair strand was washed with lukewarm water until the product was removed, and then hot-dried. After drying, a bleaching process was performed using the same steps described in treatment C.

[0034] After the treatments, these hair strands were evaluated for their color before (aMcías) and after the reaction with the copper sulfate solution (af inaj), where Aa = (aimcíaí) - (afinas). The study times were 1, 2, and 3 minutes, and the copper sulfate concentrations tested were 0.05%, 0.07%, 0.08%, 0.09%, and 0.10% in water as solvent. Colorimetric measurements were performed using a spectrophotometer, for example, a Minolta, at 3 established positions along each hair strand, before the reaction with copper sulfate (ainiciai) and after the reaction with the copper sulfate solution (afí). Sj;) 0. For evaluation and interpretation criteria, the average of the a* coordinate (color variation between green and red) was used. This parameter translates the measured color on a scale from positive a (+a), which represents the presence of the color red, to negative a (-a), which represents the presence of the color green. The greater the decrease in the parameter a, the greater the presence of the color green in the measured sample and, consequently, the greater the damage to the hair strand.

[0035] Table 4 and its respective graphs (Figures 2A, 2B, 2C, and 2D) show the results obtained during the concentration-by-reaction-time tests of the different treatments. It is possible to verify that treatments A (no damage) and B (mechanical damage) had similar delta values, due to treatment B involving the use of a flat iron, which closed the cuticles, preventing the entry or adsorption of copper into the hair fiber. It was observed that treatments C and D showed linearity of delta a* (Aa) values ​​only at concentrations of 0.05% and 0.08%. Regarding time, analyzing these concentrations, the 3-minute time had the highest delta value, and the combination of a 0.08% concentration with 3 minutes had the largest numerical scale among the treatments studied. Through these observations, the concentration and time chosen for the method and to construct the... The damage scale was 0.08% copper sulfate in water and a reaction time of 3 minutes. Table 4 Treatment Concentration of reagent 1 minute 2 minutes 3 minutes Average Treatment A 0.05% 0.34 0.12 0.50 0.32 Treatment A 0.07% -0.19 -0.09 -0.12 -0.13 Treatment A Treatment A 0.08% -0.20 0.05 0.08 -0.02 (no damage) Treatment A 0.09% -0.07 0.04 0.09 0.02 Treatment A 0.10% -0.38 -0.45 -0.26 -0.36 Treatment B 0.05% 0.13 0.19 -0.30 0.01 Treatment B 0.07% 0.17 0.14 0.21 0.17 Treatment B (Mechanical damage) Treatment B 0.08% i -0.06 0.19 0.19 0.11 Treatment B 0.09% 0.35 -0.06 -0.26 0.01 Treatment B 0.10% -0.36 -0.56 -0.05 -0.33 Treatment C 0.05% -6.77 -8.11 -8.37 -7.75 Treatment C 0.07% -5.11 -6.66 -5.25 -5.67 Treatment C (2 bleachings) Treatment C 0.08% -5.35 6.75 -7.14 -6.42 Treatment C 0.09% -5.19 -9.76 -6.91 -7.29 Treatment C 0.10% -4.80 -4.55 -6.18 -5.18 Treatment D 0.05% -7.36 -9.40 -9.77 -8.84 Treatment D Treatment D 0.07% -7.57 -10.53 -11.35 -9.82 (1 straightening and bleaching) Treatment D 0.08% -9.70 -11.30 -11.61 -10.87 Treatment D 0.09% -9.33 -10.34 -12.16 -10.61 Treatment D 0.10% -7.46 -8.53 -10.38 -8.79

[0036] With the methodology parameters defined, a new battery of tests was carried out focusing on the construction of a damage scale. For this purpose, new variations of treatments were performed, according to the methodology below.

[0037] Before receiving the treatments, the hair strands were weighed and prepared according to the Hair Strand Washing Protocol ~ Consumer Science.

[0038] The so-called E treatment is the no-damage standard, where the hair strands were simply washed according to protocol and hung on a clothesline to dry at room temperature.

[0039] Treatment F combines the mechanical damage of styling equipment for a period of 30 minutes with 20 passes of a hair straightener at 230°C, followed by... After another wash according to the protocol, it's washed for another 30 minutes in the combing machine, then washed again, and only then hung on a clothesline to dry at room temperature.

[0040] Treatment G involves bleaching as per the procedure for treatment C, followed by drying in an oven at 45°C for 30 minutes. Finally, the hair strand was washed according to the washing protocol and hung on a clothesline to dry at room temperature.

[0041] Treatment H, in turn, involves two consecutive bleaching procedures, performed twice, as in treatment G. And for treatment I, which combines three bleaching processes, the procedure was performed three times on the same strand of hair as in treatment G.

[0042] In treatment J, after washing the hair strand, it was hot-dried for 2 minutes and left to rest for 1 minute. Then, with the hair strand held on a clothesline, the straightening product, for example, Wella Professional Wellastrate Intense Straightening Cream, was applied according to the manufacturer's protocol and left to act for 25 minutes at room temperature. Next, the hair strand was washed with warm water until the product was removed, hot-dried, and straightened 10 times at 230°C. Then, the neutralizer (for example, Wella Professionals Wellastrate Neutralizing Lotion) was applied according to the manufacturer's protocol and left to act at room temperature for 15 minutes. Finally, the hair strand was washed with warm water until the product was removed and hot-dried. After the drying step, bleaching was performed using the same steps described in treatment G.

[0043] Treatment K encompasses the same procedure as the previous treatment, adding a second bleaching step afterward. In treatment L, the hair strand was subjected to the bleaching process following the same steps as treatment G (using 40 vol. developer). Following this, a coloring step was performed, for example with Truss Color Permanent 7.44 with 10-volume developer (for example, Truss Creme Developer - 10 Vol. Developer). For each hair strand, a mixture of 10 grams of Truss Color dye was used. 7.44 with 15 g of 10-volume oxidant, and the product reacted on the sample for 35 minutes. After the coloring process, the hair strand was rinsed until all product was removed and hung on a clothesline to dry at room temperature. Finally, in treatment M, the hair strand was subjected only to the coloring step as described in the previous treatment.

[0044] After the treatments, these hair strands were evaluated for their color change before (initial E) and after the reaction with the 0.08% copper sulfate solution for 3 minutes (final E). The result was given in delta E (AE) values, which numerically represent the total color change of the hair strand, unlike delta a (Aa), which was limited to the color change of the hair strand in relation to green / red and was more pronounced in light-colored hair strands. Using the AE value, it is possible to eliminate the interference of the initial hair color.

[0045] To obtain these results, colorimetric measurements of hair strands were performed using a spectrophotometer, for example Delta, at 3 established positions at the end of each hair strand, before the reaction with copper sulfate (Eimciaí) and after the reaction with the copper sulfate solution (Efinai), using a Delta spectrophotometer.

[0046] The results of the different treatments for determining damage (mechanical and chemical) showed satisfactory results, except for treatments I (three bleachings) and K (one straightening and two bleachings) where the degree of damage was so high that it compromised the hair fiber structure, as shown in Figure 3. The damage in these treatments compromised the hair fiber structure because, in addition to the degradation of pigments (eumelanin and pheomelanin), side reactions of protein oxidation occur, and the succession of three bleachings was sufficient to break all the protein bonds in the hair. For treatment K, straightening is a treatment incompatible with bleaching and also promoted high damage. For these reasons, the data from these treatments were disregarded for the construction of the scale.

[0047] Regarding the color change of the hair strands, the delta (AE) values ​​were correlated with the type of damage, showing agreement in the relationship. as per Table 5. Figure 4 shows how the ends of the hair strands looked after the reaction with 0.08% copper sulfate in water for 3 minutes. Table 5 Treatments Average delta E And without damage 1.52 F mechanical damage 1.41 G 01 discoloration 14.47 II 02 discolorations 27.20 J 01 straightening + 01 bleaching 20.8 L 01 bleaching + 01 coloring 18.57 M 01 color 2.06

[0048] For treatments E (no damage) and F (mechanical damage), the damage is similar, considered as mild damage, and these were the treatments that presented the lowest delta E values. The most aggressive treatments, those involving bleaching, were also confirmed by the delta values ​​and the green coloration of the hair strand, with treatment H (two bleachings) and treatment J (one straightening and one bleaching) being the most aggressive.

[0049] Based on this test, validation was performed to construct the proprietary damage ruler. This procedure was repeated in triplicate, with the same treatments and parameters, and consistency in the results was observed, as shown in Table 3.

[0050] With the confirmation of the damage patterns, based on the results obtained, a scale was constructed, as presented in Table 6, relating the numerical value of delta E to the level of damage. For mild damage, the range of 0 to 1 delta E value was considered, these values ​​being found in hair without chemical treatment or with mechanical damage caused by daily routines such as brushing and exposure to sun, humidity, and temperature. Mild to moderate damage, corresponding to the scale range of 2 to 5, can be found in hair that undergoes brushing, blow-drying, straightening, and even... In a coloring process, moderate damage, ranging from 5 to 12, is generated by a bleaching and coloring process, followed by moderate to high damage levels, 12-20, which includes hair that has undergone bleaching. Increasing the damage level, considering hair that undergoes straightening and bleaching, is defined as high and has a delta E numerical scale of 20 to 27. Finally, very high damage, ranging from 27 to 34, can be found in hair that undergoes two bleaching processes. Table 6 Numerical scale, Damage level, Basic treatment 0-1 light E F 2-5 mild to moderate M 5-12 moderate L 12-20 moderate to high G 20-27 high J 27-34 very high H

[0051] The method was initially developed and optimized using purchased samples of natural hair, as these offered standardization and repeatability in the benchtop steps.

[0052] However, when applied to raw human hair, lower delta E values ​​were observed than those observed in standardized (purchased) natural hair strands. This occurred because the distribution of real damage in raw human hair is not as uniform as it is in a standardized (purchased) natural hair strand that has been homogeneously damaged by standardized and controlled bleaching, dyeing, and straightening processes. Therefore, it was necessary to refine the characterization of the damage ranges without altering the inventive core. Consequently, it was possible to proportionally reduce the damage scale considering raw hair (hair in real damage conditions) versus standardized (purchased) natural hair, in association with the reagent contact time of 1-3 min without loss of performance.

[0053] The process of detecting damage in raw human hair using a reaction time of 1 minute, preferably, reduces the contact of the reagent with the raw hair, maintaining the performance and reproducibility of the method and decreasing the procedure time. Therefore, the damage scale metric was redefined as per Table 7. Table 7 Numerical scale Damage level 0-2 Light 2-5 Moderate >5 High

[0054] Furthermore, to validate the method against what is currently used by a professional hairdresser, seven (7) volunteers were selected. Hair damage was clinically assessed by the professional, who classified them into three groups: 3 with high damage, 2 with medium damage and 2 with low damage.

[0055] The hair was washed with a base shampoo by a professional hairdresser and then dried with a hairdryer. Subsequently, three strands of hair, approximately 3 cm thick and 5 cm long, were collected from each volunteer, just above the ends of the hair (the oldest region of the hair and most susceptible to damage), from representative regions of the head (middle, right side, and left side). For each strand, the white balance was measured using a previously calibrated Delta spectrophotometer, taking three readings along the strand (from the top towards the ends) and keeping the equipment on a firm surface to preserve the reference.

[0056] The sampled hair strands were then subjected to a 0.08% copper sulfate solution in a beaker, adopting a contact time between 1 and 3 minutes, also suitable for samples of fresh hair, which favors the interaction kinetics compared to purchased strands. After the contact time, hot drying and standardized combing were performed, repeating the instrumental readings at the same three points. AE, AL, Aa, and Ab were recorded, with AE being the most significant. adopted as a damage index (higher values ​​indicate greater damage). For each volunteer, the average AE was calculated for the three sampled hair strands.

[0057] The results obtained from applying the method described in this patent to samples of fresh hair, based on the new damage scale and comparing them with the damage assessment by a professional, are presented in Table 8. Table 8 Damage level Damage level, characteristics of the observed, average value. Volunteer detected with hair follicle from Delta E the professional method Medium length hair, Damage 1 with lights and good light damage 4.01 moderate caution Short hair, with coloring, thick and with background 2 light damage 1.74 light damage gray. Touch silky and homogeneous Hair with highlights, coloring, hair thinner hair gray, light roughness, damage 3 5.61 high damage distribution of moderate scattered strands (quite frontal) strand (discolored) Medium length hair, with coloring global, lights, progressive damage 4 5.62 high damage rough tips, moderate dry and with split ends and diffuse damage Hair with coloring, good damage 5 high damage 3.28 fine, rough, with moderate tips damaged, distribution not homogeneous coloring, with gray by low, hair chopped and with alopecia Thin hair, curly, dyed colored, Damage 6 medium brown, damage 2.2 high moderate texture homogeneous and silky touch Curly hair, dyed colored, brown, with damage / some threads high damage 2.82 moderate graying, slightly dry and with slight roughness

[0058] It was found that, in some cases, the clinical history did not exactly match the colorimetric result, especially on the border between "moderate" and "high". It was also noted that blonde hair with highlights and greater roughness tended to present a higher AE (delta E) on the proposed scale.

[0059] The comparison between the professional's clinical assessment and the objective AE (delta E) index demonstrates the robustness of the method by using a reproducible instrumental marker, useful for standardizing decisions. In short, the protocol works in real-world conditions (in naturd), operates with a reduced reaction time (1-3 min) without loss of performance, and guides the application of treatment according to the damage actually measured, providing greater diagnostic accuracy and directing the appropriate procedure to the state of the hair fiber.

[0060] Finally, at the end of all this development, a hair damage level determination kit is obtained, consisting of the reagent and the priority damage scale, and a method for using this kit, comprising the following execution steps: (i) determination of E inicial by spectrophotometer of the hair sample; (ii) (i) reaction of the hair sample in copper sulfate for one to three minutes; (ii) determination with the spectrophotometer of E final of the sample after the reaction with the reagent; (iv) calculation of delta E (E inicial -AND final ); and (v) comparison of the result with the priority damage scale as per Table 6 or 7.

[0061] As can be perfectly understood from this description, the kit and method proposed here are a solution for easy and effective diagnosis in determining the level of hair damage, with full application on an industrial scale.

Claims

CLAIMS 1.) “HAIR DAMAGE LEVEL DETERMINATION KIT”, characterized by comprising: a solution comprising: 0.05% to 0.10% copper sulfate, preferably 0.08%; and a proprietary ruler with a numerical scale with at least three levels of hair damage, defined as follows: an indicator of mild damage referenced by a numerical scale of color variation in color space (delta E) in a range of 0 to 2; an indicator of moderate damage referenced by a numerical scale of delta E in a range of 2 to 5; and an indicator of high damage, referenced by a numerical scale of delta E above 5. 2.) “HAIR DAMAGE LEVEL DETERMINATION KIT”, characterized by comprising: a solution comprising: 0.05% to 0.10% copper sulfate, preferably 0.08%; and a proprietary ruler with a numerical scale with at least six levels of hair damage, defined as follows: an indicator of minor damage referenced by a numerical scale of color variation in color space (delta E) in a range of 0 to 2, an indication of mild to moderate damage referenced by a numerical scale of delta E in a range of 2 to 5; an indicator of moderate damage referenced by a numerical scale of delta E in a range of 5 to 12; an indicator of moderate to high damage referenced by a numerical scale of delta E in a range of 12 to 20; an indicator of high damage referenced by a numerical scale of delta E variation in a range of 20 to 27; and an indicator of very high damage, referenced by a numerical scale of delta E in a range of 27 to 34. 3.) “METHOD FOR DETERMINING THE LEVEL OF HAIR DAMAGE”, characterized by comprising the following steps: determine an initial value of the color in the color space (E inicial ) according to the CIELAB scale of a hair strand sample using a spectrophotometer before performing hair procedures; Submerge the aforementioned hair strand sample in a solution comprising between 0.05% and 0.10% copper sulfate, preferably 0.08%, for one to three minutes, preferably one minute; to determine a final color value in the color space (Efinai) of the hair strand sample using a spectrophotometer, after the reaction of said hair strand sample with said copper sulfate solution; To determine a color variation in the color space (delta E) by the difference between the initial value of the color in the color space and the final value of the color in the color space (Einitial - Efinal); C Compare the result with a priority ruler with a numerical scale of hair damage as defined in claim 1 or 2.

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