Perm composition containing amine derivative

Abstract

The use of certain alkanolamines in hair treatment compositions as an alternative to some or all ammonium hydroxide is disclosed. These compositions are useful in curling and straightening applications. Benefits include similar or reduced hair damage; relatively mild alkalinity; the curling or straightening efficiency and the shape retentivity are very good; heating is not needed; and useful results have been obtained using different hair races.

Description

Technical Field

[0001] This invention pertains to the field of hair treatment applications. Specifically, this invention relates to alternatives to ammonium hydroxide used in alkaline curling and straightening applications. Background Technology

[0002] Human hair fibers have an outermost layer called the stratum corneum. The stratum corneum contains approximately 2-12 overlapping, flattened keratinocytes, arranged in a scaly, or "fish-scale" pattern along the longitudinal direction of the hair fiber. The second layer of hair fiber beneath the stratum corneum is the cortex. Cortical cells form a matrix that supports the keratin structure. In the cortex, protein filaments composed of long keratin chains are the main structural components of hair. These keratin chains are rich in the sulfur-containing amino acid cysteine, which forms permanent, thermally stable cross-links in the form of disulfide bonds (cystine) that bridge the keratin chains. Human hair is approximately 14-20% cysteine. The extensive disulfide bonds of cysteine ​​account for about one-third of hair strength and, except in the presence of certain dissociating or reducing agents, make hair generally insoluble.

[0003] The natural shape and structural integrity of human hair fibers depend in part on the orientation of the disulfide bonds that connect protein chains. They also depend on the secondary structure of keratin fibers. However, it is generally understood that altering disulfide bonds is necessary and / or useful for achieving long-term changes in human hair shape, such that treatments that do not rearrange disulfide bonds may only result in temporary changes in hair shape or are less effective in long-term hair reshaping. For example, using heat and moisture to style hair can produce temporary waves. However, styled hair will revert to its natural shape after a short time due to exposure to moisture in the air or washing. Using heat and moisture to style hair may damage and reconstruct hydrogen bonds in the hair, but disulfide bonds are largely unaffected. It is understandable that hydrogen bonds alone are insufficient to maintain hair shape for extended periods, as stronger disulfide bonds eventually force the hair back to its initial shape.

[0004] Throughout this specification, "perm" and "permanent waves" refer to the process of curling or straightening hair by cutting and reforming numerous disulfide bonds. Various types of permanent wave products are known. The oldest are true acid perms and alkaline perms. More recent types of perm products include acid-balanced waves, exothermic waves, endothermic waves, ammonia-free waves, sulfur-free waves, and low-pH waves.

[0005] Hair type

[0006] The effect of any perming treatment depends on the type of hair being treated. The treatment will vary depending on the exact type of hair. For hair styling purposes, the Andre Walker hair styling system is known in the art for classifying hair types. An improved version utilizes a twelve-fold classification system, in which each of the four main hair types is further divided into three subtypes A, B, and C (to indicate the degree of the main type, from less to more). The four main hair types are described below.

[0007] Type 1 (Straight): Straight hair tends to be thin and flat, with little or no volume. Type 1 hair has a thicker cuticle, making it the most resistant to regular permanent wave treatments.

[0008] Type 2 (wavy hair): Type 2 hair falls between Type 1 (straight) and Type 3 (curly) hair. Type 2 hair can be styled as curly or straight.

[0009] Type 3 (Curly Hair): Type 3 hair is characterized by its curliness, ranging from loose to elastic small loops or spirals to tight spirals. Type 3C hair is characterized by tight spirals and high volume, with less smoothness than Type 3A and Type 3B hair.

[0010] Type 4 (Kinky) Hair: Type 4 hair consists of tightly coiled strands of hair. Type 4 hair is the driest and most fragile, and therefore, traditional chemical and heat styling methods are generally avoided.

[0011] Perming methods

[0012] Perming (i.e., straightening and curling) hair by treating it with chemical agents is well-known. A typical method usually involves steps of “splitting” and “shaping” the hair, followed by treatment steps of “softening,” “molding,” and “fixing.”

[0013] Segmentation and shaping

[0014] Typically, the hair to be treated is divided into several sections. Mechanical stress is then applied to each section of the hair by positioning it in the desired shape and holding that shape with clips, curling irons, and / or other devices. For example, if the desired treatment is to curl the hair, the sections of hair can be wrapped around relatively small curling irons. Some known constructions include single-air perms, such as basic, bricklaying, spiral, directional, and root-lift perms, as well as double-air perms, such as back perms and hopscotch perms. If the desired treatment is to straighten the hair, clips and / or large curling irons and / or other devices are used to hold the sections of hair in a straight or at least less curly construction.

[0015] softening and molding

[0016] Before a large number of disulfide bonds can be broken and reformed, the cuticle must be penetrated. Each section of the hair is soaked in a shampoo containing an alkalizing agent that sufficiently softens and swells the cuticle to allow certain reducing substances to reach the cortex. Ammonia (in solution) is considered the "gold standard" in various types of hair treatments that require softening and swelling of the cuticle. As is commonly done, ammonia is provided in the form of a mixture of ammonium hydroxide and ammonium thioglycolate (called perm salt). In solution, ammonium thioglycolate is balanced with free ammonia and thioglycolic acid. Free ammonia acts as an alkalizing agent, raising the pH of the hair and softening and swelling the hair cuticle, allowing active substances and / or reagents to penetrate the hair. After the cuticle is softened, the reducing agent (i.e., thioglycolic acid) is able to break the disulfide bonds in the cortex. When thioglycolic acid molecules come close enough to the disulfide bonds in the hair cortex, the bonds break. In this process, cystine is reduced to cysteine. To make the reducing agent effective, it may also be necessary to include a pH adjuster in the detergent, although this function can also be achieved by an alkalizing agent.

[0017] The use of ammonia in hair products has many drawbacks. For example, when used, ammonia gas easily escapes into the surrounding environment, emitting a strong, unpleasant odor and irritating the skin, eyes, nose, and throat. Furthermore, treating hair with ammonium hydroxide causes some degree of damage to the hair fibers. These side effects can be experienced by both the person treating the hair and the person providing the treatment.

[0018] For these reasons, research into alternative stratum corneum penetration methods has been ongoing for decades, yielding mixed results. For example, aminomethylpropanol (AMP) and monoethanolamine (MEA) have been used as alternatives to ammonium hydroxide in some applications due to their low odor. Both molecules are known to be used as pH adjusters in cosmetic formulations. Regarding their effects on hair, the amine functional group -NH2 reacts similarly to ammonia (NH3) in ammonium thioglycolate solution, while significantly reducing the ammonia odor. However, AMP and MEA have significantly increased hair fiber damage, and this remains a major concern in the field.

[0019] Common perm solutions can be broadly categorized into alkaline and acidic perms. Common reducing agents include solutions of sodium thioglycolate (pH=9-11) and ammonium thioglycolate (pH=8.5-9.5) for alkaline perms, and solutions of glyceryl monothioglycolate (pH=6.5-7.0) for acidic perms. Acidic perms tend to be gentler on hair because glyceryl monothioglycolate tends to break fewer disulfide bonds than alkaline perm solutions.

[0020] fixed

[0021] Following the molding stage, the hair is typically rinsed thoroughly to remove as much of the reducing agent as possible. Next, an oxidizing agent capable of neutralizing the reducing agent's effects (such as hydrogen peroxide or sodium bromate) is applied and left on the hair for a short time, typically 5-10 minutes. This allows new disulfide bonds to form and anchors the hair in its new shape. The hair is then rinsed with water to remove the neutralizing agent. Optionally, an antioxidant conditioner may be applied to the hair to stop any residual oxidation process, bring the hair's pH closer to the neutral range, and smooth and seal the cuticle. Depending on the type and condition of the hair being treated, additional steps may be required anywhere in this process or as a pretreatment or post-treatment step.

[0022] The issues regarding the use of ammonium hydroxide, AMP, or MEA in hair treatments have been mentioned above. Some of these issues have been addressed in common application US17 / 656,998, which discloses the use of certain alkanolamines as alternatives to some or all of ammonium hydroxide in hair dye compositions. When used as alkalizing agents in hair dyes, these alkanolamines demonstrate reduced hair fiber damage, effective color enhancement, and significant improvements in cytotoxicity and odor compared to known alternatives to ammonium hydroxide, AMP and MEA. The following description will demonstrate the usefulness of certain alkanolamines in perm solutions and shampoos used in hair styling applications. Summary of the Invention

[0023] This application relates to alternatives to ammonium hydroxide used in alkaline perming products, the main component of which is thioglycolic acid. The compositions of the invention also contain certain alkanolamines characterized as electron donors / acceptors, making them suitable as keratin-compatible alkalizing agents for softening and swelling the hair cuticle. Perming products according to the invention have a relatively mild pH. Attached Figure Description

[0024] Figure 1 This is a scatter plot of the curling efficiency of type 1 Caucasian hair subjected to the hair curling treatment described in this article as a function of the denaturation temperature.

[0025] Figure 2 This is a scatter plot showing the curling efficiency of Type 1 Chinese hair subjected to the hair curling treatment described in this article as a function of the denaturation temperature.

[0026] Figure 3 This is a scatter plot showing the straightening efficiency of type 2C Caucasian hair subjected to the hair straightening treatment described in this article as a function of denaturation temperature. Detailed Implementation

[0027] Unless otherwise explicitly instructed, all material concentrations and reaction conditions should be understood to be modified by the word “approximately”.

[0028] The term "include" and its cognates refer to a series of elements that may not be limited to those explicitly listed.

[0029] The specific examples listed herein are merely illustrative, and the invention is not limited to those examples.

[0030] Alkalizing agent

[0031] It can be shown that certain C3-C5 alkanolamines can be used alone or in combination as alkalizing agents in perming applications. Alkanolamines consist of an alkane backbone with amino and hydroxyl functional groups. These relatively large organic molecules are not as volatile as ammonia. However, like ammonia, alkanolamines can generally produce a strongly alkaline environment that can damage hair and skin cells. Amine groups are generally considered to cause hair damage. In fact, depending on the concentration required to reproduce the benefits of ammonia in perming applications, some alkanolamines can produce more odor and / or damage than ammonia. We tested seven alkanolamine alkalizing agents shown in Table 1 to determine whether any of them provided performance benefits superior to ammonia, aminomethylpropanol (AMP), and monoethanolamine (MEA). (Note that ammonium hydroxide, MEA, and AMP are included in Table 1 for comparison only).

[0032]

[0033]

[0034] In determining which of these compounds, or combinations thereof, could provide performance benefits superior to ammonia, aminomethylpropanol (AMP), and monoethanolamine (MEA), the ability of each compound to curl and straighten hair, as well as the degree of damage caused by applying the compound to the hair, were investigated. These results are discussed below.

[0035] hair perming products

[0036] In practice, hair perming products or kits consist of two containers. The first container (I) contains a perming composition that includes a cuticle softener and a disulfide bond reducer. The perming composition is typically packaged in an airtight plastic bottle, pouch, tube, etc. The second container (II) contains a neutralizing agent composition. As explained above, the contents of containers I and II are applied to the hair in sequence.

[0037] I. Perming Composition

[0038] The perming composition of the present invention comprises an aqueous solution of one or more alkanolamine alkalizing agents and one or more thiol reducing agents. The alkanolamine alkalizing agents effectively soften and swell the hair cuticle, while the thiol reducing agents break disulfide bonds in the hair. The alkanolamine alkalizing agents in Table 1 can interact with thioglycolic acid reducing agents to form salts. In solution, the alkanolamine-thioglycolic acid salt exists as an equilibrium mixture with free thioglycolic acid and alkanolamine. In the perming composition of the present invention, the concentration of thioglycolic acid is typically about 5% to 8% by weight of the perming composition. Furthermore, the molar ratio of the alkalizing agent to thioglycolic acid should be at least 1, preferably at least 1.25, more preferably at least 1.50, and even more preferably at least 1.75, to ensure that the pH of the perming composition is greater than 7, and preferably at least 8.

[0039] Optionally, various auxiliary ingredients may be included, which impart benefits to the perming composition or hair. For example, hair-beneficial ingredients may include conditioning agents, natural oils, amino acids, peptides, proteins, vitamins, chelating agents, antioxidants, etc.

[0040] II. Neutralizing agent composition

[0041] The neutralizing agent composition used in this invention contains an oxidizing agent, typically hydrogen peroxide. This allows the formation of new disulfide bonds and fixes the hair in its new shape. Preferably, the hydrogen peroxide neutralizing agent is at least 1% (w / w). Other neutralizing agents, such as sodium bromate or sodium perborate, may also be used.

[0042] Tested perming composition

[0043] For testing purposes, we prepared the perming compositions shown in Tables 2 and 3 below. Table 2 shows the base perming composition (without alkalizing agent). Table 3 shows the amount of each individual alkalizing agent added to one of the compositions in Table 2 to complete the perming composition, as well as the pH of each perming composition. All compositions contained the same molar percentage of alkalizing agent, with the water content adjusted accordingly.

[0044]

[0045]

[0046] Percentage of active ingredients

[0047] Ammonium hydroxide (the gold standard among alkalizing agents) was used as a control, and MEA and AMP were included as commonly used alternatives to ammonium hydroxide for comparison. For comparative purposes, hair samples treated with NaOH were also included; NaOH is a very effective alkalizing agent at concentrations above a certain level, inducing significant damage to human hair. Therefore, NaOH was included as an indicator of the worst level of damage. The curling efficiency, straightening efficiency, and keratin damage of all perming compositions were tested. Data were also analyzed to evaluate the effect of pH on the performance of the perming compositions.

[0048] Curling efficiency, straightening efficiency

[0049] The ability of each test composition to curl hair was determined by measuring "curling efficiency." Curling efficiency is a measure of the tightness of the curl after hair curling treatment. Higher efficiency results in a tighter curl. We used a well-known method for measuring curling efficiency, in which a portion of hair with a known length L... u Untreated straight hair is fixed in an arrangement of pins to form a five-cycle sine wave pattern from crest to crest. Because the pins are fixed, the ideal length L of the hair portion is achieved when arranged in a five-cycle wave pattern. i It is known. From the length L u Starting with straight hair samples, the ideal result is a curly hair sample of length Li. The curliness efficiency is measured to approximate this ideal.

[0050] The ability of each test composition to straighten curly hair is determined by measuring "straightening efficiency." Straightening efficiency represents the degree to which curly hair becomes straight through a hair straightening treatment. We measure this from length L... u It begins with curly, untreated hair strands. The hair strands have an L-shape. i The ideal straight hair length, L i This is the length of an untreated hair strand when ironed to its maximum straight length. After treatment, the hair strand has a length L. t Straightening efficiency is the percentage of length gain relative to the maximum possible length gain. Higher straightening efficiency indicates better straightening results. 100% straightening efficiency means that the treated hair strands retain their maximum possible length.

[0051] Test sample preparation

[0052] Two types of hair samples were tested for curl: mixed-source Primitive Type 1 Caucasian hair and single-source Primitive Type 1 Chinese hair. For straightening, mixed-source Primitive Type 2C (very wavy) Caucasian hair was tested. Hair straightening test samples were prepared by collecting hair fibers into bundles and clamping each bundle at both ends. For the test samples to be straightened, the length L between two previously determined points was measured. u .

[0053] Curling / Straightening Stage

[0054] Wet each hair strand (with reverse osmosis water). For curling, as described above, wrap each hair strand around the board to form a five-cycle sine wave pattern. For straightening, hold each hair strand on the board in a straight configuration, apply tension, and secure the ends of the hair strand. Before proceeding, allow all test samples (curling or straightening) to dry. Immerse each board with the hair strand test sample in a beaker containing one of the perming compositions for 10 seconds. After removing the board from the solution, immediately place it in an oven at 37°C (normal body temperature) for 20 minutes. Remove the test sample from the oven and rinse it with water at 37°C for five minutes, being careful not to let the water drip directly onto the hair strand. After blotting with paper towels, allow the test sample to stand at room temperature for five minutes to allow air oxidation to occur. Remove the hair straightening test sample from the board, blow-dry and iron it at 200°C, as is commonly done in hair salon practice. At this point, measure the ideal length L between the two previously determined points mentioned above. i Then, each sample was reattached to the plate.

[0055] Fixed phase

[0056] Each bundle of hair was immersed in a 2% H₂O₂ solution for ten seconds to neutralize the reducing agent and promote SS bond formation, ensuring the bundle retains the desired shape (sine wave pattern or straight) when removed from the plate. Each bundle was left to stand at room temperature for approximately five minutes, then rinsed in running water at 37°C for five minutes, followed by patting dry with paper towels. Each test sample bundle was removed from the plate, placed on a flat surface, and allowed to dry. The fully permed, dry bundle was washed in a 5% SDS (sodium lauryl sulfate) solution (simulating salon practice) and allowed to dry overnight.

[0057] Other measurements

[0058] For the curled test sample, the length L of the five waves from peak to peak is measured. t For the straightening test sample, the final length L is measured between two previously determined points. t At this point, a portion of each hair strand test sample was measured using differential scanning calorimetry (DSC). Additionally, for lifespan performance, a GyroWash wash fastness tester was used, subjecting each hair strand to the equivalent of eight hand washes in a 5% SDS solution, followed by drying, and then another length L was tested. t Measurement.

[0059] calculate

[0060] Use Equation 1 to calculate the curling efficiency.

[0061]

[0062] L u =Length of untreated hair strands

[0063] L t =Crest-to-crest length of the five wave segments of the processed hair strand

[0064] L i =The ideal length for curly hair

[0065] (L u -L i (L) indicates the maximum possible reduction in the length of the processed result. u -L t The value indicates the actual length reduction as a result of the processing. The curl efficiency indicates the degree to which the curl does not return to its original length (straightened) when removed from the staple.

[0066] Use Equation 2 to calculate the straightening efficiency.

[0067]

[0068] L u =Length of untreated hair strands

[0069] L t =Length of the treated hair strand

[0070] L i =The ideal length of straightened hair

[0071] (L i -L u (L) indicates the maximum possible increase in the length of the processing result. t -L u The straightening efficiency is the actual increase in length as a result of the treatment. Straightening efficiency indicates the extent to which straightened hair does not return to its original length (curl) when the tension is removed.

[0072] Results and discussion

[0073] The curl efficiency results for Type 1 Caucasian hair and Type 1 Chinese hair are shown in Tables 4 and 5, respectively. The left column shows the alkalizing agent in the perming composition used to treat the hair (Table 2). The second column from the left shows the curl efficiency of the treated samples after one wash with 5% SDS solution and drying. The second column from the right shows the curl efficiency of the same samples after washing with 5% SDS solution for the equivalent of eight times and then drying. The rightmost column shows the percentage change in curl efficiency between one wash and eight washes, indicating the degree to which the treated hair retained its curl after eight washes.

[0074]

[0075]

[0076] All seven alkalizing agents tested were effective in imparting curl to both Type 1 Caucasian and Type 1 Chinese hair, and all samples retained a significant amount of curl (approximately 33% to 55% curl efficiency) after the equivalent of eight washes. For both Type 1 Caucasian and Type 1 Chinese hair, DL-2-AP was the best in imparting curl, comparable to or even better than the gold standard (ammonium hydroxide) and AMP and MEA (common alternatives to ammonium hydroxide). Of the seven alkalizing agents tested, isoserine was the second best in imparting curl to both Caucasian and Chinese hair. For both Caucasian and Chinese hair, samples treated with DL-2-AP still exhibited the greatest curl after the equivalent of eight washes, although these samples lost the most curl as a percentage of initial curl among the tested samples. Samples treated with isoserine had the second-best curl level after the equivalent of eight washes, with curl loss comparable to or better than the standards ammonium hydroxide, AMP, and MEA. All the alkalizing agents tested were effective on curly hair, retaining a significant amount of curl even after the equivalent of eight washes.

[0077] The straightening efficiency results for Caucasian hair of type 2C are shown in Table 6. The left column shows the alkalizing agent in the basic perming composition (Table 2) used to treat the hair. The right column shows the straightening efficiency of the samples treated after washing once with 5% SDS solution and drying.

[0078]

[0079] All seven alkalizing agents tested were effective in straightening type 2C Caucasian hair. Five of the seven produced significantly better results than ammonium hydroxide, AMP, and MEA. AMPD and Tris also outperformed ammonium hydroxide and MEA, but not as well as AMP. However, all the alkalizing agents tested can be used to straighten hair.

[0080] DSC analysis

[0081] As mentioned above, perming causes some degree of damage to hair fibers. This damage occurs at the keratin level. Damage occurs in the form of protein denaturation when proteins lose some of their secondary, tertiary, or quaternary structures due to the application of external stress or compounds such as strong acids or bases, concentrated inorganic salts, organic solvents (e.g., alcohols or chloroform), or heat. Denaturation of keratin in hair is known to be detectable by differential scanning calorimetry (DSC). DSC is a thermal analysis technique used to measure the phase transition temperature and heat of transition (enthalpy) of endothermic and exothermic reactions. DSC is sensitive enough to provide information about the molecular weight distribution of polymers.

[0082] For all test samples discussed above, DSC measurements were performed using a Discovery DSC 2500 (from TA Instruments, New Castle, DE). Experiments were conducted in the temperature range of 40°C to 200°C at a scan rate of 5°C / min under nitrogen protection. DSC samples were prepared by cutting hair bundle samples into small pieces (0.1–1.0 mm in size) and weighing them. Hair samples were mixed with deionized water and then sealed in a high-capacity dish for at least 6 hours before measurement. The phase transition temperature (keratin denaturation temperature) of each hair sample was analyzed using TRIOS software (Discovery DSC 2500). Untreated hair was used as a control.

[0083] Each hair sample was analyzed at least twice, and the average temperature was used for data analysis. The denaturation temperature of the control sample was subtracted from the denaturation temperature (ΔT = T). 未经处理的 - T 碱化剂 A larger ΔT indicates greater damage. For type 1 Caucasian hair that underwent curling treatment, the DSC results are shown in Table 7, arranged from the largest ΔT (maximum damage) to the smallest (minimum damage).

[0084]

[0085] The results indicate that, when used for hair curling treatment of type 1 Caucasian hair, six of the seven alkalizing agents tested (Tris, AMPD, serine, AEPD, isoserine, and DL-2-AP) caused similar or significantly less damage to Caucasian hair compared to ammonium hydroxide and / or at least one commonly used alternative to ammonium hydroxide (MEA and AMP). Tris, AMPD, and serine caused less damage than ammonium hydroxide. Only DMAMP (a tertiary amine with an OH group) performed poorly, causing almost as much damage as NaOH.

[0086] For type 1 Chinese hair that underwent curly treatment, the DSC results are shown in Table 8, arranged from maximum ΔT (maximum damage) to minimum (minimum damage).

[0087]

[0088] The results above indicate that, when used for perming type 1 Chinese hair, four of the seven alkalizing agents tested (Tris, serinel, AMPD, and AEPD) caused similar or significantly less damage to Chinese hair compared to ammonium hydroxide and / or any commonly used alternatives to ammonium hydroxide (MEA and AMP). Tris, AMPD, and serinel caused less damage than ammonium hydroxide. Furthermore, although isoserinel and DL-2-AP performed worse than the other alkalizing agents, and also worse than ammonium hydroxide, MEA, or AMP, the absolute damage levels they caused suggest that isoserinel and DL-2-AP are still suitable for perming. Similarly, alkalizing agent compositions containing DMAMP (a tertiary amine with an OH group) caused the greatest damage, even worse than NaOH.

[0089] For the type 3 Caucasian hair that underwent straightening treatment, the DSC results are shown in Table 9, arranged from maximum ΔT (maximum damage) to minimum (minimum damage).

[0090]

[0091] The results indicate that, when used for hair straightening treatment of type 3 Caucasian hair, six of the seven alkalizing agents tested produced similar or significantly less damage to Caucasian hair compared to ammonium hydroxide and / or any of its commonly used alternatives (MEA and AMP). Tris, AMPD, and serine produced less damage than ammonium hydroxide. DL-2-AP used in the straightening treatment produced more damage than ammonium hydroxide, MEA, or AMP. Unlike the curling treatment, DMAMP produced relatively little damage to Caucasian hair during straightening.

[0092] Figure 1 , 2 And 3 provide a visual representation of the results. In Figure 1 and 2 Among the samples tested, those alkalizing agents located inside the ellipse showed better performance than those tested with ammonium hydroxide, AMP, and MEA in terms of curling, curl retention, and degree of damage. Regarding curling treatment, only DMAMP (C6 alkanolamine) performed worse than ammonium hydroxide, AMP, or MEA. DL-2-AP, AMPD, AEPD, isoserine, serine, and Tris are C3-C5 alkanolamines.

[0093] exist Figure 3Among the samples tested, the alkalizing agent located inside the ellipse performed well compared to the ammonium hydroxide, AMP, and MEA samples in terms of both straightening and damage. In terms of straightening, DMAMP indeed performed well, while DL-2-AP performed poorly.

[0094] We have demonstrated that perming compositions formed from thioglycolic acid and certain C3-C5 alkanolamines (particularly those with two or more hydroxyl groups) are suitable for perming applications (curling and straightening). Thioglycolic acid, combined with the selected alkanolamines, provides excellent curling or straightening efficiency, excellent shape retention (even after the equivalent of eight washes), and causes less hair damage than the gold standard ammonium hydroxide or MEA and AMP. The perming compositions are suitable for hair of various ethnicities and have a relatively mild alkalinity (pH approximately 8.3 to 9.5), making them compatible with commercial hair care products. The most inconsistent results were achieved with DMAMP and DL-2-AP, both of which have only one hydroxyl group. However, even these demonstrate some usefulness.

[0095] Although specific embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that many other variations and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are intended to cover all such variations and modifications within the scope of the invention.

Claims

1. A perming composition comprising: 5% to 8% mercaptoacetic acid based on the weight of the perming composition; and One or more C3-C5 alkanolamines, wherein the molar ratio of alkanolamine to thioglycolic acid is at least 1; The pH of the perming composition is greater than 7.

2. The perming composition according to claim 1, wherein the one or more alkanolamines are selected from DL-2-amino-1-propanol (DL-2-AP), 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD), 3-amino-1,2-propanediol (isoserine), 2-amino-1,3-propanediol (serine), tromethamine (Tris), and 2-dimethyl-amino-2-methyl-1-propanol (DMAMP).

3. The perming composition according to claim 2, wherein the molar ratio of one or more C3-C5 alkanolamines to thioglycolic acid is at least 1.

0.

4. The perming composition according to claim 2, wherein the pH of the perming composition is at least 7.

0.

5. A hair perming product comprising a first container and a second container, wherein: The first container contains the perming composition according to claim 2; and The second container contains a neutralizing agent composition comprising hydrogen peroxide, sodium bromate, or a combination thereof.

6. The perming composition according to claim 5, wherein the molar ratio of one or more C3-C5 alkanolamines to thioglycolic acid is at least 1.

0.

7. The perming product according to claim 5, wherein the pH of the perming composition is from 7.0 to 10.

6.

8. A method of curling hair, comprising the step of applying the perming composition according to claim 2 to type 1 Caucasian hair.

9. A method of curling hair, comprising the step of applying the perming composition according to claim 2 to type 1 Chinese hair, wherein the one or more alkanolamines are selected from 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD), 3-amino-1,2-propanediol (isoserine), 2-amino-1,3-propanediol (serine), and tromethamine (Tris).

10. The method according to claim 9, wherein the one or more alkanolamines are selected from 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD), 2-amino-1,3-propanediol (serine), and tromethamine (Tris).

11. A method of straightening hair, comprising the step of applying the perming composition according to claim 2 to type 2C Caucasian hair, wherein the one or more alkanolamines are selected from 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD), 3-amino-1,2-propanediol (isoserine), 2-amino-1,3-propanediol (serine), tromethamine (Tris), and 2-dimethyl-amino-2-methyl-1-propanol (DMAMP).

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