Hair strengthening method

TECHNICAL FIELD
This invention generally relates to strengthening hair. More particularly, the invention relates to a composition and method for strengthening hair that has been exposed to a relaxer.
BACKGROUND OF THE INVENTION
Human hair has a variety of textures, from fine to coarse and from straight to very curly. Hair is made of keratin which in turn is made of polypeptide chains bonded together by cystine (or disulfide) bonds, hydrogen bonds and salt linkages. The cortex is the inner part of the hair.
Curly hair is made of hair strands that have irregular surfaces that mesh and tangle with each other to make combing more difficult. Among individuals with excessively curly hair, e.g., individuals of African or Middle Eastern descent, it is especially popular to relax or straighten hair to increase hair manageability and ease of styling. The hair to be relaxed is either pressed or exposed to a relaxer that chemically transforms cystine bonds of the hair to lanthionine bonds. For this reason, the term for the chemical relaxing process is lanthionization.
During chemical relaxing, the hair is wetted with the relaxer and repeatedly smoothed and sometimes partially combed. Typical relaxers contain an alkali metal hydroxide or guanidine hydroxide as an active ingredient. The relaxers greatly decrease the tensile strength of the hair making it more likely to break. Hair being relaxed that is still wet loses as much as 45-50 percent (%) of the hair's original tensile strength. Relaxed hair that is dry loses about 20-25% of the hair's original tensile strength. It is presently theorized that the decrease in tensile strength is due to structural damage associated with .alpha.-helical deformation which occurs during relaxing.
The .alpha.-helical deformation of hair can occur under the following conditions:
a) When the high alkalinity relaxers degrade cystine bonds of the .alpha.-keratine during straightening, partial deformation of the .alpha.-helix becomes a reality which causes the loss of tensile strength in the hair fibers.
b) Partial deformation of .alpha.-helix could be caused by the mechanical extension of hair fibers beyond yield and post-yield region which may not be reversible, even when the fibers are allowed to relax, i.e., rest in water.
c) During relaxing, degradation of cystine bonds and low level of mechanical force applied while applying and smoothing relaxer cream on hair causes the deformation of .alpha.-helix in keratine fibers.
In chemical relaxing, once the desired degree of straightening is achieved, the relaxer is rinsed from the hair with water. The hair is then cleansed using a low pH, acidic nondetangling shampoo which is known as a neutralizing shampoo. After shampooing, the hair is very raspy in nature and rough to the touch.
Conditioners are often applied to the hair after shampooing to soften the hair. Quaternary ammonium compounds having chain lengths of about 11 to about 18 carbon atoms are often a component of these conditioners. Unfortunately, most of these compounds do not work when exposed to the relaxer or shampoo, and, therefore, they can only be used in post-shampooing conditioners. For example, U.S. Pat. Nos. 5,060,680 and 5,148,822, both to Akhtar, disclose straightening hair by a method that requires removing substantially all of the relaxer from the hair prior to applying an aqueous hair texturing and strengthening composition to the hair. Furthermore, these compounds do not strengthen hair when incorporated into the relaxer.
It is, therefore, an object of the present invention to provide an improved hair strengthening composition and easy-to-use method for strengthening hair.
SUMMARY OF THE INVENTION
The present invention provides an improved composition and method for strengthening hair. The composition and method are particularly useful for strengthening human hair straightened by a high alkalinity relaxer. The present composition and method strengthen the hair even in the presence of the relaxer.
According to the invention, a composition for treating hair includes a hair swelling component and a cationic polymer in an amount effective to strengthen the hair. The hair swelling component is preferably the high alkalinity hair relaxer. The hair strengthening cationic polymer is a water-dispersible polyquaternary ammonium polymer that is the reaction product of a lower dialkylamine (C.sub.1 -C.sub.3), a difunctional epoxy-type reactant and a third reactant selected from the group consisting of ammonia, primary amines, alkylene diamines having two to six carbon atoms and polyamines.
The method includes the steps of applying a hair swelling component to hair in need of strengthening and applying the cationic polymer to hair.
It is presently theorized that the hair swelling component swells the hair to permit the cationic polymer to be affixed to the swollen hair, preferably to the hair cortex. The affixed cationic polymer remains on or in the hair even after the hair swelling component and cationic polymer that is not affixed are removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A hair strengthening composition includes a hair swelling component and a cationic polymer.
The hair swelling component is capable of swelling the hair to facilitate the cationic polymer to be affixed to the swollen hair. A preferred hair swelling component is a high alkalinity hair relaxer that can have a pH in the range of about 11 to about 13.5.
The high alkalinity hair relaxer can be a multi-part hair relaxer system or a single part hair relaxer. Multi-part relaxer systems having two parts are known wherein the active hair relaxing ingredient, e.g., guanidine hydroxide, is generated in situ by the combination of the two parts. Typically, the multi-part relaxer system includes a cream relaxer as part A and a liquid activator as part B. Preferably, the cationic polymer is a component of the cream relaxer. Also present in the cream relaxer is one precomponent of the active hair relaxing ingredient. A preferred precomponent is a hydroxide such as an alkaline earth hydroxide, e.g., calcium hydroxide. The liquid activator contains a second precomponent of the active hair relaxing ingredient, such as those disclosed in U.S. Pat. No. 4,314,572 to de la Guardia. The de la Guardia patent and all other patents, articles and the like referred to or otherwise identified in this specification are incorporated herein by reference in their entirety. A preferred second precomponent is guanidine carbonate. When parts A and B are mixed together, the calcium hydroxide and the guanidine carbonate react with the reaction product being produce guanidine hydroxide, the active hair relaxing ingredient. The cream relaxer, Part A, may also include additional conventional components. The liquid activator, Part B, typically also includes deionized water.
The single part hair relaxer preferably uses a hydroxide such as an alkali metal hydroxide, e.g., sodium hydroxide, as the active hair relaxing ingredient. The remaining components of the single part hair relaxer are conventional.
The hair strengthening cationic polymer is described in more detail in U.S. Pat. No. Re. 28,808 to Panzer et al and U.S. Pat. No. 4,661,259 to Walterick et al. and is referred to in the '259 patent as a group (II) cationic polymer at column 3, lines 43 et seq. The cationic polymer is a water-dispersible polyquaternary polymer that is the reaction product of a lower dialkylamine (C.sub.1 -C.sub.3), a difunctional epoxy-type reactant and a third reactant selected from the group consisting of ammonia, primary amines, alkylenediamines having two to six carbon atoms and polyamines.
Representative epoxy-type reactants include epihalohydrins, e.g., epichlorohydrin and epibromohydrin with epichlorohydrin being the preferred epihalohydrin, diepoxides, e.g., 1,4-butanediol-diglycidyl ethers, and precursors of epihalohydrins and diepoxides, e.g., 1,3-dichloropropanol-2 and 1,4-dichloro-2,3-dihydroxybutane.
Representative polyamines include polyalkylpolyamines having the structure disclosed in the '259 patent at column 3, lines 64 et seq.
The exact reaction parameters for the cationic polymer are specified in the '808 reissue patent and need not be repeated herein.
The preferred cationic polymer is the reaction product of a secondary amine and epihalohydrin in the presence of a small amount of ethylenediamine. See, for instance, EXAMPLE 2 of the '808 reissue patent.
It is presently theorized that the preferred cationic polymer has the following structure: ##STR1##
The molecular weight of the cationic polymer is in the range of about 400.times.10.sup.3 to about 1.times.10.sup.6 with the molecular weight of the preferred cationic polymer being in the range of about 400-600.times.10.sup.3.
The cationic polymer in admixture with water is commercially available from Betz Laboratories, Trevose, Pa. under the designation Betz polymer 1195. The Betz polymer 1195 typically contains about 50 weight percent (wt %) of the cationic polymer and has an activity of about fifty percent.
The hair swelling component is present in the hair strengthening composition in an amount in the range of about 95 to about 99.5 wt % based upon the total weight of the hair-strengthening composition. The cationic polymer is present in an amount in the range of about 0.5 to about 5 wt %.
The method of strengthening hair in need of strengthening includes the steps of applying the hair swelling component to the hair and applying the cationic polymer. Preferably, the applying steps are performed simultaneously. The hair is preferably contacted with the hair swelling component for a time period sufficient to swell the hair. Some of the cationic polymer becomes affixed to the swollen hair. An aliquot of the cationic polymer can be affixed by penetrating the swollen hair, especially the cortex of the hair. The cationic polymer that is not affixed can be removed as by rinsing the hair with water. The hair swelling component can also be removed, or can be neutralized, using water or a conventional neutralizer.
The following tests were used to determine the efficacy of the hair strengthening composition containing a relaxer as the hair swelling component and the cationic polymer on wet and dry hair fibers.
Wet Hair Fibers
To determine the efficacy of the hair strengthening composition on wet hair fibers, twelve inch long European dark brown hair, commercially available from DeMeo Brothers, New York is washed with a mild shampoo containing 10% ammonium lauryl sulfate. The hair fibers are rinsed with tepid tap water for about two minutes and dried overnight at ambient temperature, i.e., a temperature in the range of about 20.degree. to about 30.degree. C. Twenty-five shampooed fibers having approximately the same diameter, i.e. a diameter in the range of about 71 to about 80 microns, are selected and then each fiber is cut into two halves. The hair fibers with the root end of the hair are identified as Group A, fibers 1-25, and are used as a control which is only treated with the relaxer. The hair fibers having the tip end are identified as Group B, fibers 26-50, and are treated with either the strengthening composition containing the relaxer and the strengthening cationic polymer or the relaxer and a comparison, nonstrengthening cationic polymer. The root end of the hair fibers is known to be slightly stronger than the tip end because the root end has had less exposure to damaging conditions. Therefore, one would expect that the length of hair having the root end would have a higher tensile strength than the hair fiber having the tip end. The Group A and B hair fibers are then immersed in tap water for at least 30 minutes.
The initial work done to extend the hair fibers 20% of their original length of 30 millimeters (mm) is conventionally referred to as an F20 Index Study and is determined using a conventional Dia-Stron MTT under conditions well known to those skilled in the art. The value of the initial work done to achieve 20% elongation is equal to X. The hair fibers of each group are then immersed in separate containers of water and allowed to recover overnight in the water. After recovering, the hair fibers are mounted on separate rectangular processing slabs and dried at ambient temperature for 30 minutes before treatment with the relaxer (Group A) or treatment with the strengthening composition or the relaxer and comparison polymer (Group B) for 18 minutes. The hair fibers are rinsed with tepid tap water for three minutes, treated with diluted nonconditioning neutralizing shampoo for three minutes, rinsed with tepid tap water for one minute, unmounted and stored overnight in water. The hair fibers are then elongated 20% using the Dia-Stron MTT while being periodically immersed in the water. Immersion is accomplished by mounting each end of a hair fiber sample into the holding clamps of a remote measurement jig for movement into and out of a water-filled compartment. The value of the work done after treatment with the relaxer to achieve 20% elongation is equal to Y. The F20 Index is determined using the following Equation I:
F20 Index=[(X-Y)/X].times.100 I.
Dry Hair Fibers
The above-described Group A and B hair fibers are equilibrated at 65% relative humidity and 21.degree. C. overnight before determining the work required to extend them 20% of their original length. The initial work done to achieve 20% elongation of the equilibrated hair fibers is determined using the Dia-Stron MTT at the above-described parameters. The value of the initial work done is equal to X. After testing, the hair fibers are immersed in water and allowed to recover overnight. The hair fibers are then mounted by group on separate rectangular processing slabs and dried for 30 minutes at ambient temperature. The hair fibers are then treated with a relaxer (Group A) or with the strengthening composition or the relaxer and comparison polymer (Group B) for 18 minutes. The hair fibers are then rinsed with tepid tap water for three minutes, treated with diluted nonconditioning neutralizing shampoo for three minutes, rinsed with tepid tap water for one minute, unmounted, stored in water for one hour and transferred to an environmental room at 65% relative humidity and 21.degree. C. overnight. The dry hair fibers are then elongated 20% using the Dia-Stron MTT at the above-described test parameters to determine the work done after treatment with the relaxer. The value of the work done after treatment is equal to Y. The F20 Index is then determined using the above-described Equation I.
The relaxers, hair strengthening compositions and comparison polymer-containing relaxers used in the examples had the compositions provided in TABLES 1 and 2, below.
TABLE 1__________________________________________________________________________Guanidine-Containing Relaxers Control Merquat 100 -Containing Relaxer Hair Strengthening Polycare 133 - ContainingComponents (Wt %) (Wt %) Composition (Wt %) Relaxer (Wt %) Relaxer__________________________________________________________________________PART A: CreamDeionized Water 50.73 48.33 47.73 47.09Propylene Glycol 2.00 2.00 2.00 2.00Calcium Hydroxide 5.50 5.50 5.50 5.50PEG-75 Lanolin 2.25 2.25 2.25 2.25Betz Polymer 1195 (50%) -- 2.40 -- --Merquat 100 (40%) -- -- 3.00 --Polycare 133 (33%) -- -- -- 3.64Petrolatum 12.00 12.00 12.00 12.00Mineral Oil 18.00 18.00 18.00 18.00Fatty Alcohol 8.00 8.00 8.00 8.00Ceteth-20 1.50 1.50 1.50 1.50Mazu DF 200S 0.02 0.02 0.02 0.02PART B: Liquid ActivatorGuanidine Carbonate 25.00Deionized Water 75.00__________________________________________________________________________
TABLE 2______________________________________Sodium Hydroxide-Containing Relaxers Control Relaxer Hair StrentheningIngredients (Wt %) Composition (Wt %)______________________________________Deionized Water 55.03 53.03Propylene Glycol 2.00 2.00Sodium Hydroxide (50%) 4.50 4.50PEG-50 Lanolin 0.49 0.49Betz Polymer 1195 -- 2.00Petrolatum 12.00 12.00Mineral Oil 17.00 17.00Emulsifying Wax 10.00 10.00Laneth-15 0.98 0.98______________________________________
The following examples are given by way of illustration and not limitation. In the following examples, if the coefficient of variance is considerably above 10, it is advisable to eliminate fibers with unusually low or high average work done to bring the coefficient of variance up to 10. Therefore, those fibers were eliminated to bring down the coefficient of variance into the desirable range.

EXAMPLE I
Determination of F20 Index for Wet Fibers Treated with a Guanidine Relaxer and Hair Strengthening Composition Including a Guanidine Relaxer
The F20 Index was determined using the procedure described above under the "WET HAIR FIBER" heading and the control guanidine relaxer and the Betz polymer 1195-containing hair strengthening composition of TABLE 1, above. The test results are provided in TABLES 3 and 4, below.
TABLE 3______________________________________Group A Wet Fibers: Control, Treated WithGuanidine Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 1 1.150 0.541 52.96 2 1.390 0.687 50.58 3 1.500 0.714 52.40 4 1.470 0.662 54.97 6 1.370 0.607 55.69 7 1.520 0.784 48.42 9 1.270 0.595 53.1511 0.939 0.432 53.9912 1.180 0.461 60.9313 1.090 0.519 52.3914 1.430 0.694 51.4715 1.170 0.613 47.6117 0.921 0.414 55.0518 0.992 0.501 49.5019 1.290 0.677 47.5220 1.220 0.632 48.2021 1.180 0.573 51.4422 1.170 0.605 48.2923 1.410 0.725 48.5825 1.120 0.542 51.61AVERAGE 51.74STANDARD DEVIATION 3.39(SAMPLE)COEFFICIENT OF VARIANCE 6.54______________________________________ *WORK DONE IS IN MILLIJOULES The standard deviation is for the sample of data. The coefficient of variance is determined by the following Equation II: II. Coefficient of Variance = (Standard Deviation/Average) .times. 100
TABLE 4______________________________________Group B Wet Fibers: Experimental, Treated WithGuanidine Relaxer and Cationic Polymer Betz 1195 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________26 1.040 0.513 50.6727 1.640 0.950 42.0728 1.440 0.819 43.1329 1.190 0.668 43.8730 1.430 0.842 41.1231 1.290 0.636 50.7034 1.270 0.706 44.4135 1.250 0.757 39.4436 0.816 0.429 47.4337 1.110 0.562 49.3738 1.010 0.589 41.6839 1.370 0.767 44.0141 1.160 0.646 44.3142 0.956 0.454 52.5144 1.210 0.659 45.5445 1.240 0.688 44.5246 1.060 0.461 56.5147 1.100 0.617 43.9148 1.090 0.513 52.9450 1.050 0.517 50.76AVERAGE 46.44STANDARD DEVIATION 4.63(SAMPLE)COEFFICIENT OF VARIANCE 9.96______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 3 and 4, the average tensile strength loss was more than 11% less for the wet hair fibers treated with the hair strengthening composition of the present invention as compared to those treated with the Control. This reduction in loss of tensile strength means that the hair fibers are stronger and less prone to damage and breakage as compared to hair treated with the Control.
EXAMPLE II
Determination of F20 Index for Dry Fibers Treated with a Guanidine Relaxer and a Hair Strengthening Composition Including a Guanidine Relaxer
The F20 Index was determined using the procedure described above under the "DRY HAIR FIBER" heading and the control guanidine relaxer and the Betz polymer 1195-containing hair strengthening composition of TABLE 1, above. The test results are provided in TABLES 5 and 6, below.
TABLE 5______________________________________Group A Dry Fibers: Control, Treated WithGuanidine Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 1 2.570 1.910 25.68 3 1.950 1.510 22.56 5 2.640 1.980 25.00 6 2.890 2.240 22.49 9 2.830 2.140 24.3815 1.970 1.470 25.3816 2.860 2.060 27.9717 3.190 2.360 26.0218 1.970 1.460 25.8919 3.030 2.350 22.4423 1.750 1.340 23.43AVERAGE 24.66STANDARD DEVIATION 1.78(SAMPLE)COEFFICIENT OF VARIANCE 7.21______________________________________ *WORK DONE IS IN MILLIJOULES
TABLE 6______________________________________Group B Dry Fibers: Experimental, Treated WithGuanidine Relaxer and Cationic Polymer Betz 1195 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________26 2.590 2.030 21.6227 3.040 2.420 20.3928 2.540 1.990 21.6535 3.020 2.390 20.8637 2.990 2.250 24.7540 2.250 1.680 25.3341 3.110 2.350 24.4442 2.980 2.280 23.4944 3.100 2.360 23.8749 2.540 2.000 21.2650 2.610 2.070 20.69AVERAGE 22.58STANDARD DEVIATION 1.82(SAMPLE)COEFFICIENT OF VARIANCE 8.05______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 5 and 6, the average tensile strength loss was more than 9% less for the dry hair fibers treated with the hair strengthening composition of the present invention as compared to those treated with the Control. This reduction in loss of tensile strength means that the hair fibers are stronger and less prone to damage and breakage as compared to hair treated with the Control.
EXAMPLE III
Determination of F20 Index for Wet Fibers Treated with a Sodium Hydroxide Relaxer and a Hair Strengthening Composition Including a Sodium Hydroxide Relaxer
The F20 Index was determined using the procedure described above under the "WET HAIR FIBER" heading and the control sodium hydroxide relaxer and the Betz polymer 1195-containing hair strengthening composition of TABLE 2, above. The test results are provided in TABLES 7 and 8, below.
TABLE 7______________________________________Group A Wet Fibers: Control, Treated WithSodium Hydroxide Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 3 1.540 0.966 37.27 4 1.210 0.660 45.45 5 1.360 0.738 45.74 6 1.260 0.711 43.57 8 1.290 0.697 45.9712 1.520 0.958 36.9713 1.420 0.756 46.7615 0.944 0.571 42.5616 0.895 0.512 42.7917 1.040 0.581 44.1318 1.310 0.796 39.2419 1.110 0.650 41.4423 1.640 0.964 41.2225 1.080 0.588 45.56AVERAGE 42.76STANDARD DEVIATION 3.20(SAMPLE)COEFFICIENT OF VARIANCE 7.48______________________________________ *WORK DONE IS IN MILLIJOULES
TABLE 8______________________________________Group B Wet Fibers: Experimental, Treated WithSodium Hydroxide Relaxer and Cationic Polymer Betz 1195 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________27 1.080 0.734 32.0430 1.240 0.949 31.5333 1.340 0.884 34.0335 0.755 0.526 30.3337 1.340 0.934 30.3038 1.300 0.855 34.2339 1.230 0.865 29.6740 0.875 0.549 37.2641 0.820 0.490 40.2442 1.090 0.707 35.1444 1.070 0.727 32.0646 1.240 0.851 31.3747 1.140 0.675 40.7948 1.660 1.040 37.35AVERAGE 34.02STANDARD DEVIATION 3.67(SAMPLE)COEFFICIENT OF VARIANCE 10.78______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 7 and 8, the average tensile strength loss was more than 25% less for the wet hair fibers treated with the hair strengthening composition of the present invention as compared to those treated with the Control. This reduction in loss of tensile strength means that the hair fibers are stronger and less prone to damage and breakage as compared to hair treated with the Control.
EXAMPLE IV
Determination of F20 Index for Dry Fibers Treated with a Sodium Hydroxide Relaxer and a Hair Strengthening Composition Including a Sodium Hydroxide Relaxer
The F20 Index was determined using the procedure described above under the "DRY HAIR FIBER" heading and the control sodium hydroxide relaxer and the Betz polymer 1195-containing hair strengthening composition of TABLE 2, above. The test results are provided in TABLES 9 and 10, below.
TABLE 9______________________________________Group A Dry Fibers: Control, Treated WithSodium Hydroxide Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 2 3.170 2.540 19.87 3 2.250 1.840 18.22 4 2.230 1.780 20.18 6 2.300 1.910 16.96 8 2.950 2.340 20.6810 2.440 1.950 20.0812 2.490 2.010 19.2818 2.790 2.320 16.8519 2.190 1.790 18.2620 2.870 2.230 22.3021 2.400 1.830 23.7522 3.130 2.390 23.6425 2.880 2.250 21.88AVERAGE 20.15STANDARD DEVIATION 2.28(SAMPLE)COEFFICIENT OF VARIANCE 11.30______________________________________ *WORK DONE IS IN MILLIJOULES
TABLE 10______________________________________Group B Dry Fibers: Experimental, Treated WithSodium Hydroxide Relaxer and Cationic Polymer Betz 1195 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________26 2.410 1.950 19.0928 2.780 2.200 20.8629 2.350 1.900 19.1533 3.120 2.600 16.6735 2.380 1.970 17,2336 3.410 2.750 19.3538 2.910 2.310 20.6241 2.640 2.140 18.9445 2.870 2.390 16.7246 2.290 1.940 15.2847 2.920 2.470 15.4148 3.170 2.660 16.0949 2.950 2.430 17.63AVERAGE 17.93STANDARD DEVIATION 1.87(SAMPLE)COEFFICIENT OF VARIANCE 10.45______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 9 and 10, the average tensile strength loss was more than 12% less for the dry hair fibers treated with the hair strengthening composition of the present invention as compared to those treated with the Control. This reduction in loss of tensile strength means that the hair fibers are stronger and less prone to damage and breakage as compared to hair treated with the Control.
EXAMPLE V
Determination of F20 Index for Wet Fibers Treated with a Guanidine Relaxer and a Merquat 100-Containing Relaxer
The F20 Index was determined using the procedure described above under the "WET HAIR FIBER" heading and the Control guanidine relaxer and the Merquat 100-containing guanidine relaxer of TABLE 1, above.
The test results are provided in TABLES 11 and 12, below.
TABLE 11______________________________________Group A Wet Fibers: Control, Treated WithGuanidine Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 1 1.460 0.631 56.78 3 0.983 0.363 63.07 4 1.210 0.425 64.88 5 1.270 0.567 55.35 6 0.990 0.376 62.02 7 1.240 0.337 72.82 8 1.610 0.612 61.99 9 1.180 0.553 53.1410 1.040 0.365 64.9011 0.877 0.290 66.9312 1.110 0.424 61.8013 1.010 0.404 60.0014 1.080 0.384 64.4415 1.160 0.460 60.3416 1.020 0.416 59.2217 1.220 0.404 66.8918 1.410 0.708 49.7919 1.050 0.427 59.3320 1.610 0.570 64.6021 1.060 0.469 55.7522 1.340 0.482 64.0323 0.936 0.355 62.0724 1.240 0.413 66.6925 1.120 0.442 60.54AVERAGE 61.56STANDARD DEVIATION 5.02(SAMPLE)COEFFICIENT OF VARIANCE 8.15______________________________________ *WORK DONE IS IN MILLIJOULES
TABLE 12______________________________________Group B Wet Fibers: Experimental, Treated WithGuanidine Relaxer and Cationic Polymer Merquat 100 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________26 1.420 0.582 59.0127 1.020 0.423 58.5328 0.998 0.349 65.0329 1.180 0.382 67.6330 1.130 0.487 56.9031 0.884 0.291 67.0832 1.550 0.538 65.2933 1.070 0.460 57.0134 1.080 0.347 67.8735 0.711 0.212 70.1836 1.160 0.384 66.9037 0.819 0.338 58.7338 1.020 0.357 65.0039 1.400 0.477 65.9340 0.923 0.384 58.4041 1.260 0.384 69.5242 1.380 0.626 54.6443 0.982 0.360 63.3444 1.650 0.590 64.2445 1.100 0.447 59.3646 1.370 0.529 61.3947 0.987 0.275 72.1448 1.250 0.359 71.2849 1.360 0.412 69.71AVERAGE 63.71STANDARD DEVIATION 5.09(SAMPLE)COEFFICIENT OF VARIANCE 7.98______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 11 and 12, the percent loss of tensile strength is actually greater for the hair fibers treated with the Merquat 100-containing guanidine relaxer as compared to the hair fibers treated with the Control guanidine relaxer. The Merquat 100 is commercially available from Calgon Corporation, Pittsburgh, Pa. The Merquat 100 is dially dimethyl ammonium chloride. Thus, the hair fibers treated with the Merquat 100-containing relaxer are more likely to break or be damaged than the hair fibers treated with the Control.
EXAMPLE VI
Determination of F20 Index for Wet Fibers Treated with a Guanidine Relaxer and a Polycare 133-Containing Relaxer
The F20 Index was determined using the procedure described above under the "WET HAIR FIBER" heading and the Control guanidine relaxer and the Polycare 133-containing guanidine relaxer of TABLE 1, above. The Polycare 133 is commercially available from Rhone Poulene, Cranbury, Nev. The Polycare 133 is polymethylacrylamidopropyl trimunium chloride.
The test results are provided in TABLES 13 and 14, below.
TABLE 13______________________________________Group A Wet Fibers: Control, Treated WithGuanidine Relaxer Without Cationic Polymer Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________ 1 1.540 0.748 51.43 2 0.865 0.421 51.33 3 1.330 0.618 53.53 4 1.190 0.467 60.76 5 1.410 0.512 63.69 6 0.889 0.382 57.03 7 0.983 0.345 64.90 8 1.400 0.553 60.50 9 1.140 0.397 65.1810 0.957 0.268 72.0011 1.590 0.619 61.0712 1.360 0.602 55.7413 1.030 0.371 63.9814 1.090 0.408 62.5715 1.540 0.672 56.3616 1.540 0.633 58.9017 1.200 0.453 62.2518 1.560 0.541 65.3219 1.580 0.783 50.4420 1.190 0.515 56.7221 1.250 0.517 58.6422 0.941 0.557 40.8123 1.050 0.337 67.9024 1.090 0.513 52.9425 0.796 0.327 58.92AVERAGE 58.92STANDARD DEVIATION 6.63(SAMPLE)COEFFICIENT OF VARIANCE 11.25______________________________________ *WORK DONE IS IN MILLIJOULES
TABLE 14______________________________________Group B Wet Fibers: Experimental, Treated WithGuanidine Relaxer and Cationic Polymer Polycare 133 Initial Work F20 IndexFiber Work Done* After After Relaxer TreatmentNo. Done* (X) Relaxer (Y) (% Loss in Tensile Strength)______________________________________26 1.440 0.672 53.3327 1.000 0.479 52.1028 1.310 0.582 55.5729 1.200 0.397 66.9230 1.390 0.484 65.1831 1.010 0.408 59.6032 0.987 0.317 67.8833 1.610 0.652 59.5034 1.170 0.468 60.0035 0.964 0.266 72.4136 1.590 0.604 62.0137 1.320 0.517 60.8338 0.972 0.337 65.3339 1.240 0.439 64.6040 1.600 0.623 61.0641 1.680 0.778 53.6942 1.050 0.342 67.4343 1.440 0.515 64.2444 1.510 0.670 55.6345 1.350 0.502 62.8146 1.200 0.400 66.6747 1.320 0.524 60.3048 0.969 0.279 71.2149 1.240 0.574 53.7150 0.793 0.302 61.92AVERAGE 61.75STANDARD DEVIATION 5.71(SAMPLE)COEFFICIENT OF VARIANCE 9.24______________________________________ *WORK DONE IS IN MILLIJOULES
As can be seen from TABLES 13 and 14, the percent loss of tensile strength is actually greater for the hair fibers treated with the Polycare 133-containing guanidine relaxer as compared to the hair fibers treated with the Control guanidine relaxer. Thus, the hair fibers treated with the Polycare 133-containing relaxer are more likely to break or be damaged than the hair fibers treated with the Control.
It is presently theorized that the above-described advantages are achieved because the swelling of the hair fiber by the hair swelling component permits the cationic polymer to be affixed to the hair. The cationic polymer can be affixed by mechanical or chemical bonding to the hair. The swelling of the hair permits the cationic polymer to penetrate into the cortex of the hair fiber and form an elastic network in the cortex. Even after the hair is rinsed, the polymer is locked inside the hair to increase the tensile strength of the hair fiber due to the elastic nature of the cationic polymer.

Number	Name	Date
3811835	Gallup et al.	May 1974
3954113	Bohrer et al.	May 1976
4299817	Hannan, III et al.	Nov 1981
4319020	Coscia et al.	Mar 1982
4397322	Arbaczawski	Aug 1983
4579131	Syed	Apr 1986
4943430	Hefford et al.	Jul 1990
5037818	Sime	Aug 1991
5060680	Akhtar	Oct 1991
5077042	Darkwa et al.	Dec 1991
5147635	Jachowicz et al.	Sep 1992
5149752	Jachowicz et al.	Sep 1992
5338540	Lee et al.	Aug 1994
5476650	Patel	Dec 1995

Hair strengthening method

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