Hair shaping material

Abstract

The present invention relates to novel hair treatment materials, and in particular materials for shaping hair and/or strengthening the hair. Also described are the use of these compounds in hair care formulations for shaping, straightening, strengthening or treating the hair, and the use of the compounds for hair straightening and/or hair strengthening.

Claims

1. A hair treatment formulation comprising a hydrolysed protein which comprises a Bunte salt of cystine, wherein the cystine is present in an amino acid chain of the hydrolysed protein, the hydrolysed protein having an average molecular weight range of 100 to 500 Daltons, wherein the hydrolysed protein which comprises a Bunte salt of cystine is present in the hair treatment formulation in about 5 wt. %, wherein the hair treatment formulation comprises about 2 wt. % urea based on the total weight of the formulation and 2.5 wt. % to 5 wt. % sodium sulphite based on the total weight of the formulation, and wherein curled hair treated with the hair treatment formulation is straighter than curled hair treated with a corresponding hair treatment formulation not containing the Bunte salt.

2. A method of treating hair, comprising applying the hair treatment formulation according to claim 1 to hair.

3. A method of straightening hair, comprising applying the hair treatment formulation according to claim 1 to hair.

4. The hair treatment formulation according to claim 1, wherein the formulation also strengthens hair.

5. The hair treatment formulation according to claim 1, wherein the formulation further comprises non-ionic and/or anionic surfactants.

6. The hair treatment formulation according to claim 5, wherein the non-ionic and/or anionic surfactants are present in an amount of 5 wt. % to 30 wt. % by weight of the total formulation.

7. The hair treatment formulation according to claim 1, wherein the formulation further comprises a silicone fluid or oil.

8. The hair treatment formulation according to claim 7, wherein the silicone fluid or oil is present in an amount of 0.3 wt. % to 20 wt. % by weight of the total formulation.

9. The hair treatment formulation according to claim 1 in combination with an acid having a pH of 2 to 6.

Description

EXAMPLES

Example 1—Bunte Salt Synthesis

(1) Water (793 g) and hydrochloric acid (28%, 342 g) were mixed in a glass reactor vessel and heated to 60° C. Milled wool fibres (600 g) were slowly added to the hot acid while stirring until all the fibres were wetted by the acid. After adding the wool, the reaction mixture was heated to 120° C. to hydrolyse the wool.

(2) The contents of the vessel were then heated to reflux for 7 hours. After this time the reaction mixture was cooled to room temperature and filtered. The filter cake was washed with water until the wash water showed a refractive index of 0%. The washings and filtrate were collected and passed through an anion exchange column to remove the chloride ions.

(3) The low ash solution was then mixed with activated carbon (90 g) and stirred for 4 hours. The carbon was then filtered out and the solution was carbon treated for a second time. The protein solution was then evaporated to a refractive index of approximately 35% and preserved.

(4) Sodium metabisulphite was added to the protein solution and the pH adjusted to 5.0-5.5 before mixing vigorously for 24 hours. Hydrogen peroxide (35%) was then added to the product prior to final pH adjustment and filtration.

Example 2—Test Formulation

(5) A series of test formulations were made according to the following generic formulation:

(6) TABLE-US-00001 TABLE 1 Test formulation A Ingredient % w/w Water (deionised) To 100 Urea 2 Sodium Sulfite 5 Bunte Active of Example 1 5 (% active) Citric acid (50%) To pH 4.5

(7) The Bunte active used had a Mw of 173 Da using the SE-HPLC method as defined herein.

(8) TABLE-US-00002 TABLE 2 Test Formulation B Ingredient/INCI Name % w/w Part A Brij S2 (Steareth-2).sup.1 5.00 Brij S721 (Steareth-21).sup.1 2.00 Crodacol CS50 (Cetearyl Alcohol).sup.1 1.75 Mineral Oil 25cS at 25° C. 1.50 Part B Pricerine 9091 (Glycerin).sup.1 3.00 Keltrol CG-SFT (Xanthan Gum).sup.4 1.50 Part C Water Deionised (Aqua) To 100 Sodium Sulphite 2.50 Urea 2.00 Part D Bunte salt of Cystine (Example 1) 26.88  Peppermint Cool Fragrance.sup.2 2.00 Euxyl PE9010 (Phenoxyethanol 0.80 (and) Ethylhexylglycerin).sup.3

(9) Test Formulation B was prepared by pre-mixing the Part B ingredients and combining the Part C ingredients with stirring until dissolved. Part B was then added to Part C with stirring. The Part A ingredients were then mixed and heated to 65-70° C. The Part BC mixture was also heated to the same temperature as Part A and then added to Part A with stirring. The heat was removed and once the mixture had reached 40° C., Part D was added with stirring. The resulting formulation was stirred to cool.

(10) The following comparative formulation was also made to act as a benchmark with test formulations A and B. Comparative formulation 1 (C1) (negative benchmark)—water (pH 4.5)

Example 3—Hair Straightening Test Protocol

(11) The formulations were subjected to the following test protocol to evaluate the effectiveness as a hair straightening agent.

(12) Materials Curly Hair Swatches (Brazilian, IHIP. L250 mm, W5 mm) Round Brush Flat Irons (GHD model 4.2 B) Hair Dryer

(13) Hair Treatment

(14) Hair used was selected to have a prominent curl. The hair to be used was washed once with basic shampoo (0.5 mL) rinsed (30 s) and allowed to dry naturally. A photo of the hair swatch was taken as a “Before Treatment” record.

(15) The hair swatch was then laid flat in 100 mL of the test solution and covered in cling film. The hair was left in the solution for 30 minutes, and then the swatch was combed through once every 10 minutes for a total of 30 minutes. Any excess solution was removed from the swatch via squeezing (twice) and then blotted on a paper towel. The hair was dried with a hair dryer and round barrel brush until approximately 80-90% dry which took around 30 seconds.

(16) The treated hair swatch was straightened with flat irons for five passes, each under maximum tension. Each pass took seven seconds and a wide tooth comb was used to direct the hair when ironing.

(17) Maintenance Step

(18) The swatch was washed with basic shampoo (0.5 mL) and rinsed (30 seconds). The hair was dried with a hair dryer and round barrel brush until approximately 80-90% dry which took around 30 seconds. The treated hair swatch was straightened with flat irons for five passes, each under maximum tension. Each pass took seven seconds and a wide tooth comb was used to direct the hair when ironing. The hair switch was photographed as a record for “After Treatment”.

(19) Straightness Retention Step

(20) The swatch was washed with basic shampoo and rinsed. The swatch was combed through once and then allowed to dry naturally. The swatch was then photographed, with this labelled as ‘1 Wash’.

(21) The Straightness Retention process was repeated a further 29 times to give a total of 30 washes. Photographs were taken at 1, 5, 10, 15, 20, 25 and 30 washes.

(22) Results

(23) After being treated the hair swatch was measured both in terms of length and width. The shorter and wider the hair swatch the curlier the hair, and therefore this indicated limited hair straightening. A hair swatch which was longer and narrower was therefore an indication of hair that had been treated with an effective hair straightener. Hair straightness may also be assessed visually.

(24) TABLE-US-00003 TABLE 3 Hair straightening results Length Width (cm) (cm) Swatch A C1 A C1 Before 20.13 19.2 4.28 9.87 After 22.58 23.75 3.16 3.59  1 Wash 22.09 21.07 3.3 7.4  5 Wash 26.01 20.68 3.99 10.69 10 Wash 22.94 3.99 20 Wash 22.49 5.48 30 Wash 24.05 4.7

(25) As can be seen from the results, the treated hair has greater length and less width that the hair washed with the comparative. This clearly indicates the hair remains straighter and curls less when treated with the material of the present invention. The effect can also be seen to last for several washes after the treatment meaning time between repeat treatments may be longer than seen with prior art materials.

Example 4—Hair Strengthening Test Protocol

(26) A—Tensile Strength

(27) Tensile testing is possibly the most common way of evaluating hair strength as it involves physically pulling hair fibres and measuring the resisting force up until the fibre breaks. Although the break point can be measured, other tensional parameters can be measured as the hair is placed under tensile stress.

(28) Materials and Equipment Automatic crimper (AAS1600 by Dia-Stron or similar sample preparation equipment) Laser micrometer (Dia-Stron LSM-5000 or equivalent) Tensile tester (Dia-Stron MTT690 or equivalent) Humidity controlled chamber/room, set at 50% relative humidity (RH) (for assessment of dry hair properties) Brass tabs Hair tresses (Brazilian hair with curl type III) that have been prepared by being bleached 3 times.

(29) Treatment

(30) Test Formulation B detailed in the table above, and Comparative Formulation C1, were applied to separate samples of 3-times bleached Brazilian hair with curl type III, saturating the hair tresses by applying the equivalent of 2.5 g of formulation per gram of hair. The saturated hair tresses were then left to rest for 30 minutes at ambient temperature and humidity, to ensure disruption to the maximum number of disulphide bonds within the hair and allow optimum time for actives to penetrate the hair fibre. Following this rest period, and before removing the formulation, the hair tresses were blow dried until completely dry. The hair tresses were then straightened using 10 passes of thermal straightening irons over the length of the tresses (Babyliss, 210° C.). The hair tresses were then left to rest for 15 minutes before being washed with a simple shampoo, blow dried until completely dry and then straightened using 10 passes of the thermal straightening irons once again. Finally, the hair tresses were left to rest for 5 days before being evaluated.

(31) Procedure

(32) Dry Hair Measurements 1. 30 to 50 hair fibres per treatment were prepared by crimping the fibres individually between brass tabs using the automatic crimper. 2. The fibres were equilibrated at 50% RH for 2 hr. 3. The fibre diameter was measured using the laser micrometer. This was done by taking 3 measurements along the length of the hair fibre to obtain an average value representative of the entire fibre. 4. The fibres were equilibrated again at 50% RH for 2 hr. 5. The strain rate in the tensile tester was set to 20 mm/min. 6. Each fibre was then strained up to the fracture point using the tensile tester and the measurements from the tensile tester recorded. Average (mean) results were calculated using results from each fibre.

(33) Wet Hair Measurements 1. 30 to 50 hair fibres per treatment were prepared by crimping the fibres individually between brass tabs using the automatic crimper. 2. The prepared fibres were soaked in DI water for at least 30 min. 3. The fibre diameter was measured using the laser micrometer. This was done by taking 3 measurements along the length of the hair fibre to obtain an average value representative of the entire fibre. 4. The fibres were individually placed in the tensile tester's cassette and the pockets filled with DI water to soak the fibres, making sure there was no overflow. 5. The strain rate in the tensile tester was set to 20 mm/min. 6. Each fibre was then strained up to the fracture point using the tensile tester and the measurements from the tensile tester recorded. Average (mean) results were calculated using results from each fibre.

(34) Results

(35) In the tensile strength measurements, a higher result is reflective of a higher tensile strength. From the results in Table 4 below, it can be seen that the treatment of bleached hair fibres with Test Formulation A leads to an improved/increased tensile strength over the untreated, bleached hair.

(36) TABLE-US-00004 TABLE 4 Tensile strength results Wet/Dry Hair Comparative Test Fibres Measurement Formulation C1 Formulation B Dry Average Young's 4.08E+09 Pa 4.20E+09 Pa Modulus Wet Average Young's 1.10E+09 Pa 1.22E+09 Pa Modulus Wet Average Plateau 3.74E−03 gmf/sq. 4.19E−03 gmf/sq. Stress micron micron Wet Average Break 1.51E−02 gmf/sq. 1.68E−02 gmf/sq. Stress micron micron Wet Average Postyield 4.47 gmf/mm 4.96 gmf/mm Gradient

(37) B—Differential Scanning Calorimetry

(38) Differential Scanning calorimetry uses the measurement of heat flow to determine structural changes as a result of increasing temperature. Although not a direct evaluation of hair strength, a higher temperature at which the proteins within a hair fibre denature indicates more a more intact protein structure. Damaging treatments, such as those mentioned above, lead to a reduction in the denaturation temperature which correlates well with tensile testing measurements as well as consumer feedback relating to poorer quality, weaker hair with more breakage.

(39) Materials & Equipment Differential Scanning calorimeter (DSC) Hair tresses (Brazilian hair with curl type III) High pressure, high volume aluminium pans Products/formulations to be tested

(40) Operating Parameters:

(41) Temperature range: 50° C. to 190° C. (no dehydration/water evaporation step needed) Heating rate: 10° C./min

(42) Treatment

(43) Hair tresses were prepared for the DSC measurements in the same way as described above for the tensile strength test. In addition to the 3-times bleached samples treated with Test formulation B and Comparative Formulation C1, this test involved the use of virgin hair sample, ie those which had not been bleached or subjected to any other treatment steps.

(44) Sample Preparation 1. For each treatment to be evaluated, about 100 mg of hair was cut into ˜2 mm sections (hair resembled a powder at this particle size). 2. The hair “powders” were stored at constant relative humidity (45%) overnight. 3. 5-7 mg of hair powder was weighed into large volume-pressure resistant stainless steel capsules. Three capsules were prepared for each treatment to be evaluated in order for an average (mean) to be calculated. 4. 50 microliters of deionized water was added to each capsule using a micropipette. 5. The capsules were sealed and stored overnight for equilibration. 6. The denaturation enthalpy was then measured for each capsule sample using the DSC.

(45) Results

(46) For the DSC results, a higher denaturation temperature (Td) value represents more structure within the hair. The results are shown below in Table 5. The hair structure is damaged by bleach, so a higher value result, indicating increased structure, is a sign of the strengthening of the hair structure.

(47) TABLE-US-00005 TABLE 5 DSC results Td (° C.) Capsule 1 Capsule 2 Capsule 3 average Td (° C.) Virgin hair 154.91 155.17 155.34 155.14 Comparative 149.26 148.72 148.65 148.88 Formulation C1 Test Formulation 157.7 157.54 157.71 157.65 B

Example 5—Formulation Examples

(48) Strong and Straight Shampoo

(49) TABLE-US-00006 Ingredients % Part A Deionized Water To 100 Dissodium EDTA 0.10 Part B Sodium Laureth Sulfate (27% active solution) 15.00 Crodasinic LS 30 (Aqua (and) Sodium Lauroyl Sarcosinate) 10.00 Crodateric CAB 30 (Aqua (and) Cocamidopropyl Betaine) 8.00 Arlasilk PLN (Linoleamidopropyl PG-Dimonium Chloride 1.00 Phosphate Dimethicone (and) Aqua) Dimethiconol (and) TEA-Dodecylbenzenesulfonate 2.00 Part C Crodapearl ™ AF (Water & Sodium Laureth 3.50 Sulphate & Glycol Distearate) Crothix ™ liquid (PEG-150 Pentaerythrityl 4.20 Tetrastearate (and) Aqua (and) PEG-6 Caprylic/Capric Glycerides) Bunte salt of Cystine (Example 1) 3.00 Preservative 0.50 Fragrance 0.50 Part D Citric Acid To pH 5.50-6.50 Suppliers: 1: Croda

(50) Procedure

(51) The ingredients of parts A and B were mixed separately, with moderate stirring. Part A was added to part B with moderate stirring. The ingredients of phase C were then added, in the order described. The pH was adjusted, if necessary, using part D.

(52) Hair Strengthening Cream Conditioner

(53) TABLE-US-00007 Ingredients % Part A Water Deionized To 100 Disodium EDTA 0.05 Glycerine 1.00 Part B Incroquat Behenyl TMS 50 (Cetearyl 2.00 Alcohol and Behentrimonium Methosulfate).sup.1 Crodazosoft DBQ (Quaternium-91 (and) 1.30 Cetrimonium Methosulfate (and) Cetearyl Alcohol).sup.1 Cetearyl Alcohol 3.00 Crodamol STS (PPG 3 Benzyl Ether Myristate).sup.1 1.00 KeraDyn HD ((Bis-Ethyl(isostearylimidazoline) 0.50 Isostearamide).sup.1 Dimethicone 0.50 Part C Bunte salt of Cystine (Example 1) 5.00 Phenoxyethanol 0.50 Fragrance 0.50 Suppliers: 1. Croda

(54) Procedure

(55) Part A and Part B were combined separately and heated to 75-80° C. The oil phase was then slowly added to the water phase with stirring and once added, the stirring was maintained for about 10 minutes. The mixture was then stirred slowly to cool down. Once cool, Part C was added, and the pH adjusted, if necessary.

(56) It is to be understood that the invention is not to be limited to the details of the above embodiments, which are described by way of example only. Many variations are possible.