Method for reducing hair damage upon exposure to heating

Abstract

The present invention provides a method for reducing hair damage upon exposure to heating, the method comprising: providing an aqueous carrier; selecting a heat protectant, wherein the heat protectant is selected based on its ability to confer heat protection to hair and is selected as a modified carbohydrate polymer, the modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: a trialkylammonium moiety; and a hydrophobic substituent having 16 carbon atoms; providing the selected heat protectant; combining the cosmetically acceptable aqueous carrier and the heat protectant to form an aqueous heat protectant preparation; wherein the aqueous heat protectant preparation contains 0.1% to 5% by weight of the heat protectant based on the weight of the aqueous heat protectant preparation; providing hair; applying the aqueous heat protectant preparation to the hair; providing a heated hair care appliance; using the heated hair care appliance to expose the hair to heating at 50°C to 300°C for 1 minute to 30 minutes.

Description

[0001] The present invention relates to a method for reducing hair damage when hair is exposed to heating. Specifically, the present invention relates to a method for reducing hair damage when hair is exposed to heating, the method comprising: providing a cosmetically acceptable aqueous carrier; selecting a heat protectant, wherein the heat protectant is selected based on its ability to confer heat protection to hair against exposure to heating, wherein the heat protectant is selected as a modified carbohydrate polymer, the modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I)

[0002]

[0003] wherein each R 1 is independently selected from C 1-7 alkyl groups, and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of from 0.75 wt% to 2.5 wt%; and (ii) a hydrophobic substituent each having 16 carbon atoms; wherein the modified carbohydrate polymer comprises from 0.005 wt% to 1.5 wt% of hydrophobic substituents based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituents are randomly distributed on the backbone of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M W > 1,000,000 daltons; and wherein the modified carbohydrate polymer comprises < 0.001 wt% of crosslinked units based on the weight of the modified carbohydrate polymer; providing the selected heat protectant; combining the cosmetically acceptable aqueous carrier and the heat protectant to form an aqueous heat protectant formulation; wherein the aqueous heat protectant formulation contains from 0.1 wt% to 5 wt% of the heat protectant based on the weight of the aqueous heat protectant formulation; providing hair; applying the aqueous heat protectant formulation to the hair; providing a heated hair care appliance; and using the heated hair care appliance to expose the hair to heating at a temperature of from 50°C to 300°C for from 1 minute to 30 minutes.

[0004] (For example, during heat-assisted styling or drying using a hair dryer, straightening device (such as a straightening iron), crimping device, heated comb, heated brush (with or without a drum), heat-assisted processes for applying heat to hair fibers are prevalent. However, such heat-assisted processes can dry and damage the hair. In addition, improper techniques can cause damage; improper techniques such as, for example, holding the hair dryer too close to the hair and over-drying the hair, or by keeping the hair in contact with the heating tool at a particular hair point for too long. Heat-assisted processes can cause water evaporation or expulsion from the hair, resulting in the hair becoming brittle and more prone to breakage. In addition, heat styling can cause physical damage to the hair. For example, by lifting the cuticle and / or creating blisters on individual hair fibers, increased friction between the hair fibers can occur. Increased friction between the hair fibers makes combing more difficult, and thus requires greater force to comb the hair. The application of increased combing force can then wear down the outer surface of the hair, resulting in breakage and splitting of the hair. For many years, researchers thought that human hair had temperature-based properties similar to wool, since both are composed of keratin. Recent studies have shown that human hair exhibits the following characteristics in response to heating. (a) When exposed to heating at ≤150 °C, loosely bound water and tightly bound water are lost or evaporated from human hair. (b) When exposed to heating at 160 °C to 175 °C, human hair undergoes a glass transition phase; where the hair begins to flow like a hot glass. At the glass transition temperature, the hair can undergo plastic deformation. Normally hydrated hair can be elastically stretched and return to its original length. Thus, normally hydrated hair exhibits temporary plasticity, which is why styles such as curls and twists / knots can occur. However, when processed at temperatures above the glass transition temperature, the plasticity of the hair is not temporary. After cooling, the hair can retain the style, but the hair shaft will be damaged. (c) When exposed to heating at 215 °C to 235 °C, the keratin that exists as a natural α-helix in all hair melts, permanently damaging the hair. Note that hair styling is typically performed using tools that exhibit operating temperatures in excess of 150 °C to impart a style to the hair above the glass transition. When using heat to style the hair, the temperature required to exceed the glass transition temperature is proportional to the hydration level of the hair. The higher the water content of the hair, the lower the temperature required to reach the glass transition point of the hair. Therefore, in order to cause the lowest possible level of undesired damage to the hair, it would be advantageous to maximize the hydration of the hair during the heat-assisted styling process.)

[0005] A method for treating keratin fibers is described by Greaves et al. in WO 2019043032. Greaves et al. disclose a method for treating keratin fibers, especially human keratin fibers, particularly hair, which method comprises: (i) the step of applying to said fibers a) one or more monosaccharides having amine groups; (ii) the step of applying to said fibers b) one or more polysaccharides having amine groups; (ii′) an optional drying step; (iii) then a heat treatment step at a temperature of 80° C. or higher, especially at a temperature between 100° C. and 250° C., preferably using a hair straightening iron; It should be understood that steps (i) and (ii) can be carried out simultaneously or successively, preferably, steps (i) and (ii) are carried out simultaneously, and when present, the drying step (ii′) is before the heat treatment step and after steps (i) and (ii).

[0006] Nevertheless, there is still a need for methods to reduce hair damage when the hair is exposed to heating.

[0007] The present invention provides a method for reducing hair damage when the hair is exposed to heating, which method comprises: providing a cosmetically acceptable aqueous carrier; selecting a heat protectant, wherein the heat protectant is selected based on its ability to confer heat protection to the hair against exposure to heating, and comprises a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I)

[0008]

[0009] wherein each R 1 is independently selected from C 1-7 alkyl groups, and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of from 0.75% to 2.5% by weight; and (ii) a hydrophobic substituent each having 16 carbon atoms; wherein the modified carbohydrate polymer comprises from 0.005% to 1.5% by weight of hydrophobic substituents based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituents are randomly distributed on the backbone of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M W; and wherein the modified carbohydrate polymer comprises < 0.001% by weight of crosslinked units, based on the weight of the modified carbohydrate polymer; providing a selected heat protectant; combining a cosmetically acceptable aqueous carrier and the heat protectant to form an aqueous heat protectant formulation; wherein the aqueous heat protectant formulation contains 0.1% to 5% by weight of the heat protectant, based on the weight of the aqueous heat protectant formulation; providing hair; applying the aqueous heat protectant formulation to the hair; providing a heated hair care appliance; and exposing the hair to heating at a temperature of 50°C to 300°C for 1 minute to 30 minutes using the heated hair care appliance. Detailed Description

[0010] We have surprisingly found that hair treated with the aqueous heat protectant formulation of the present invention prior to exposure to heating; wherein the aqueous heat protectant formulation comprises a selected heat protectant, wherein the heat protectant is selected based on its ability to confer heat protection to the hair against exposure to heating, wherein the heat protectant is selected as a modified carbohydrate polymer, the modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I)

[0011]

[0012] wherein each R 1 is independently selected from C 1-7 alkyl groups, and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN, corrected for ash and volatiles, of 0.75% to 2.5% by weight; and (ii) a hydrophobic substituent each having 16 carbon atoms; wherein the modified carbohydrate polymer comprises 0.005% to 1.5% by weight of the hydrophobic substituent, based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituents are randomly distributed along the backbone of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M W > 1,000,000 daltons; and wherein the modified carbohydrate polymer comprises < 0.001% by weight of crosslinked units, based on the weight of the modified carbohydrate polymer; the treated hair exhibits at least one of the following: a higher denaturation temperature than hair similarly exposed to heating but not treated with the aqueous protectant formulation and a higher denaturation enthalpy than hair similarly exposed to heating but not treated with the aqueous protectant formulation.

[0013] Unless otherwise indicated, ratios, percentages, parts, etc. are by weight.

[0014] As used herein, unless otherwise specified, the phrase "molecular weight" or M WRefers to the weight-average molecular weight measured by gel permeation chromatography (GPC) in a conventional manner using conventional standards such as polyethylene glycol standards. The GPC technique is described in detail in "Modern Size Exclusion Chromatography", W.W. Yau, J.J. Kirkland, D.D. Bly, Wiley-Interscience, 1979, and in "A Guide to Materials Characterization and Chemical Analysis", J.P. Sibilia, VCH, 1988, pages 81-84. Molecular weights are reported herein in Daltons (Dalton) or equivalently g / mol.

[0015] As used herein and in the appended claims, the term "cosmetically acceptable" refers to ingredients commonly used in personal care compositions and is intended to emphasize that substances that are toxic when present in the amounts typically found in personal care compositions are not considered as part of the present invention.

[0016] Preferably, the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention comprises: providing a cosmetically acceptable aqueous carrier; selecting a heat protectant, wherein the heat protectant is selected based on its ability to impart heat protection to the hair against exposure to heating, and wherein the heat protectant is selected as a modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I)

[0017]

[0018] wherein each R 1 is independently selected from C 1-7 alkyl groups (preferably C 1-4an alkyl group; more preferably, a methyl group and an ethyl group; most preferably, a methyl group), and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of 0.75 wt% to 2.5 wt% (preferably, 0.8 wt% to 2.2 wt%; more preferably, 1.5 wt% to 2.1 wt%; most preferably, 1.7 wt% to 1.9 wt%); and (ii) a hydrophobic substituent each having 16 carbon atoms; wherein the modified carbohydrate polymer comprises > 0.005 wt% to 1.5 wt% (preferably, 0.1 wt% to 1.1 wt%; more preferably, 0.2 wt% to 0.7 wt%; still more preferably, 0.3 wt% to < 0.5 wt%; most preferably, 0.4 wt% to 0.46 wt%) of the hydrophobic substituent based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituents are randomly distributed on the backbone of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M of > 1,000,000 daltons (preferably, 1,100,000 daltons to 4,000,000 daltons; more preferably, 1,200,000 daltons to 2,000,000 daltons; most preferably, 1,300,000 daltons to 1,800,000 daltons) W; and wherein the modified carbohydrate polymer comprises <0.001% by weight, preferably <0.0001% by weight, more preferably <0.00001% by weight, and most preferably less than the limit of detection, based on the weight of the modified carbohydrate polymer> of crosslinking units; providing a selected heat protectant; combining a cosmetically acceptable aqueous carrier and the heat protectant to form an aqueous heat protectant formulation (preferably, wherein the aqueous heat protectant formulation comprises 25% to 99.95% by weight, preferably 50% to 99.9% by weight, more preferably 75% to 99.5% by weight, and most preferably 80% to 99.3% by weight, based on the weight of the aqueous heat protectant formulation> of a cosmetically acceptable aqueous carrier; and 0.1% to 5% by weight, preferably 0.15% to 2.5% by weight, more preferably 0.2% to 2% by weight, and most preferably 0.25% to 1.5% by weight, based on the weight of the aqueous heat protectant formulation> of the heat protectant); providing hair; applying the aqueous heat protectant formulation to the hair (preferably, 0.01 g to 5 g of an aqueous hair care preparation); optionally, rinse the hair with water (preferably, wherein the hair is rinsed before the aqueous protective agent preparation is applied to the hair); optionally, dry the rinsed hair by at least one of blotting and squeezing the hair to remove excess water (preferably, wherein the hair is dried by at least one of blotting and squeezing the hair to remove excess water before the aqueous protective agent preparation is applied to the hair); optionally, comb and / or brush the hair at least one of after the aqueous heat protective agent preparation is applied (preferably, wherein the hair is combed and / or brushed before, during, and / or after the hair is exposed to heating from a heated hair care appliance); provide a heated hair care appliance (e.g., perming / curling with a straightening iron; styling and heating the hair in a curling iron; curling the hair with a curling iron; and hot rollers) (a hair styling appliance, wherein the hair styling appliance is selected from at least one of a hair dryer, a hot air styler, and a curling iron); expose the hair to heating at a temperature of 50 °C to 300 °C (preferably, 80 °C to 280 °C; more preferably, 90 °C to 275 °C; most preferably, 100 °C to 250 °C) for 1 minute to 30 minutes using a heated hair care appliance (e.g., for drying the hair or styling the hair) (preferably, for drying the hair, provide a hot air hair care appliance and a hot surface hair care appliance for 1 minute to 20 minutes, and then for styling the hair, treat the hair with a hot surface hair care appliance for 1 minute to 20 minutes) (preferably, wherein the hair to which the aqueous protective agent preparation has been applied exhibits at least one of the following: a higher denaturation temperature than hair similarly exposed to heating but not treated with the aqueous protective agent preparation and a higher denaturation enthalpy than hair similarly exposed to heating but not treated with the aqueous protective agent preparation) (more preferably, wherein the hair to which the aqueous protective agent preparation has been applied exhibits a higher denaturation temperature and a higher denaturation enthalpy than hair similarly exposed to heating but not treated with the aqueous protective agent preparation).

[0019] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a cosmetically acceptable aqueous carrier. More preferably, the aqueous heat protection agent formulation provided and used in the method of the present invention comprises 25% to 99.95% by weight (preferably, 50% to 99.9% by weight; more preferably, 75% to 99.5% by weight; more preferably, 80% to 99.3% by weight) of a cosmetically acceptable aqueous carrier based on the weight of the aqueous heat protection agent formulation. More preferably, the aqueous conditioning agent formulation of the present invention comprises 25% to 99.95% by weight (preferably, 50% to 99.9% by weight; more preferably, 75% to 99.5% by weight; most preferably, 80% to 99.3% by weight) of a cosmetically acceptable aqueous carrier based on the weight of the aqueous heat protection agent formulation; wherein the cosmetically acceptable carrier includes water.

[0020] Preferably, the water used in the aqueous heat protection agent formulation prepared and used in the method of the present invention is at least one of distilled water and deionized water. More preferably, the water used in the aqueous heat protection agent formulation prepared and used in the method of the present invention is distilled and deionized.

[0021] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent. More preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of a heat protection agent based on the weight of the aqueous heat protection agent formulation. Most preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of a heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to confer heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer, the modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I)

[0022]

[0023] wherein each R 1 is independently selected from C 1-7 alkyl groups (preferably, C 1-4an alkyl group; more preferably, a methyl group and an ethyl group; most preferably, a methyl group), and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of 0.75 wt% to 2.5 wt% (preferably, 0.8 wt% to 2.2 wt%; more preferably, 1.5 wt% to 2.1 wt%; most preferably, 1.7 wt% to 1.9 wt%); and (ii) a hydrophobic substituent, wherein the hydrophobic substituent comprises an alkyl group having 16 carbon atoms; wherein the modified carbohydrate polymer comprises > 0.005 wt% to 1.5 wt% (preferably, 0.1 wt% to 1.1 wt%; more preferably, 0.2 wt% to 0.7 wt%; still more preferably, 0.3 wt% to < 0.5 wt%; most preferably, 0.4 wt% to 0.46 wt%) of the hydrophobic substituent based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituents are randomly distributed on the backbone of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M of > 1,000,000 daltons (preferably, 1,100,000 daltons to 4,000,000 daltons; more preferably, 1,200,000 daltons to 2,000,000 daltons; most preferably, 1,300,000 daltons to 1,800,000 daltons) W ; and wherein the modified carbohydrate polymer comprises < 0.001 wt% (preferably, < 0.0001 wt%; more preferably, < 0.00001 wt%; most preferably, less than the limit of detection) of crosslinked units based on the weight of the modified carbohydrate polymer.

[0024] Preferably, the cellulose ether matrix material has a weight average molecular weight M of > 1,000,000 daltons (preferably, 1,100,000 daltons to 4,000,000 daltons; more preferably, 1,200,000 daltons to 2,000,000 daltons; most preferably, 1,300,000 daltons to 1,800,000 daltons) W More preferably, the cellulose ether matrix material has a weight average molecular weight M of > 1,000,000 daltons (preferably, 1,100,000 daltons to 4,000,000 daltons; more preferably, 1,200,000 daltons to 2,000,000 daltons; most preferably, 1,300,000 daltons to 1,800,000 daltons) W; wherein the cellulose ether matrix material is selected from: hydroxyethyl cellulose, carboxypropyl cellulose, ethyl hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and mixtures thereof. Still more preferably, the cellulose ether matrix material has a weight average molecular weight M greater than 1,000,000 Daltons (preferably, from 1,100,000 Daltons to 4,000,000 Daltons; more preferably, from 1,200,000 Daltons to 2,000,000 Daltons; most preferably, from 1,300,000 Daltons to 1,800,000 Daltons). W ; wherein the cellulose ether matrix material is selected from: hydroxyethyl cellulose, hydroxypropyl cellulose, and mixtures thereof. Most preferably, the cellulose ether matrix material has a weight average molecular weight M greater than 1,000,000 Daltons (preferably, from 1,100,000 Daltons to 4,000,000 Daltons; more preferably, from 1,200,000 Daltons to 2,000,000 Daltons; most preferably, from 1,300,000 Daltons to 1,800,000 Daltons). W ; wherein the cellulose ether matrix material is hydroxyethyl cellulose.

[0025] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises from 0.1% to 5% by weight (preferably, from 0.15% to 2.5% by weight; more preferably, from 0.2% to 2% by weight; most preferably, from 0.25% to 1.5% by weight) of the heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to confer heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I), wherein each R 1 is independently selected from C 1-7 alkyl groups (preferably, C 1-4an alkyl group; more preferably, a methyl group and an ethyl group; most preferably, a methyl group), and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of from 0.75% to 2.5% by weight (preferably, from 0.8% to 2.2% by weight; more preferably, from 1.5% to 2.1% by weight; most preferably, from 1.7% to 1.9% by weight). More preferably, the aqueous heat protection agent formulation prepared and used in the process of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the process of the present invention comprises from 0.1% to 5% by weight (preferably, from 0.15% to 2.5% by weight; more preferably, from 0.2% to 2% by weight; most preferably, from 0.25% to 1.5% by weight) of a heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to confer heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer; wherein the modified carbohydrate polymer comprises a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I), wherein each R 1 is independently selected from C 1-7 alkyl groups (preferably, C 1-4 alkyl groups; more preferably, a methyl group and an ethyl group; most preferably, a methyl group); wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of from 0.75% to 2.5% by weight (preferably, from 0.8% to 2.2% by weight; more preferably, from 1.5% to 2.1% by weight; most preferably, from 1.7% to 1.9% by weight); and wherein the modified carbohydrate polymer contains <0.1 mole (preferably, <0.01 mole; more preferably, <0.001 mole; most preferably, less than the limit of detection) of a trialkylammonium moiety of formula (II) per mole of cellulose ether matrix material

[0026]

[0027] wherein each R 2 is independently selected from a methyl group and an ethyl group, and wherein R 3 is selected from C 8-30 alkyl groups.

[0028] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of the heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to impart heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer; wherein the modified carbohydrate polymer comprises a cellulose ether matrix material functionalized with (ii) hydrophobic substituents, wherein the hydrophobic substituents include alkyl groups having 16 carbon atoms; wherein the modified carbohydrate polymer comprises >0.005% to 1.5% by weight (preferably, 0.1% to 1.1% by weight; more preferably, 0.2% to 0.7% by weight; still more preferably, 0.3% to <0.5% by weight; most preferably, 0.4% to 0.46% by weight) of the hydrophobic substituents based on the weight of the cellulose ether matrix material. More preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of the heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to impart heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer; wherein the modified carbohydrate polymer comprises a cellulose ether matrix material functionalized with (ii) hydrophobic substituents, wherein the hydrophobic substituents include alkyl groups having 16 carbon atoms and are bonded to the cellulose ether matrix material through at least one of an ether bond (e.g., a single ether bond or an ether bond and a 2-hydroxypropyl group) and an ester bond; wherein the modified carbohydrate polymer comprises >0.005% to 1.5% by weight (preferably, 0.1% to 1.1% by weight; more preferably, 0.2% to 0.7% by weight; still more preferably, 0.3% to <0.5% by weight; most preferably, 0.4% to 0.46% by weight) of the hydrophobic substituents based on the weight of the cellulose ether matrix material.Still more preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of the heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to impart heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer; wherein the modified carbohydrate polymer comprises a cellulose ether matrix material functionalized with (ii) hydrophobic substituents, wherein the hydrophobic substituents include alkyl groups having 16 carbon atoms and are bonded to the water-soluble cellulose ether matrix material through at least one of an ether bond (e.g., a single ether bond or an ether bond and a 2-hydroxypropyl group) and an ester bond; wherein the modified carbohydrate polymer comprises >0.005% to 1.5% by weight (preferably, 0.1% to 1.1% by weight; more preferably, 0.2% to 0.7% by weight; still more preferably, 0.3% to <0.5% by weight; most preferably, 0.4% to 0.46% by weight) of the hydrophobic substituents based on the weight of the cellulose ether matrix material; and wherein the hydrophobic groups are randomly distributed on the main chain of the cellulose ether matrix material. Most preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises a heat protection agent, wherein the aqueous heat protection agent formulation prepared and used in the method of the present invention comprises 0.1% to 5% by weight (preferably, 0.15% to 2.5% by weight; more preferably, 0.2% to 2% by weight; most preferably, 0.25% to 1.5% by weight) of the heat protection agent based on the weight of the aqueous heat protection agent formulation; wherein the heat protection agent is selected based on its ability to impart heat protection to hair against exposure to heating, and wherein the heat protection agent is selected as a modified carbohydrate polymer; wherein the modified carbohydrate polymer comprises a cellulose ether matrix material functionalized with (ii) hydrophobic substituents, wherein the hydrophobic substituents include alkyl groups having 16 carbon atoms and are bonded to the water-soluble cellulose ether matrix material through at least one of an ether bond or an ether bond and a 2-hydroxypropyl group; wherein the modified carbohydrate polymer comprises >0.005% to 1.5% by weight (preferably, 0.1% to 1.1% by weight; more preferably, 0.2% to 0.7% by weight; still more preferably, 0.3% to <0.5% by weight; most preferably, 0.4% to 0.46% by weight) of the hydrophobic substituents based on the weight of the cellulose ether matrix material; and wherein the hydrophobic groups are randomly distributed on the main chain of the cellulose ether matrix material.

[0029] Preferably, the modified carbohydrate polymer has the formula (III)

[0030]

[0031] wherein n is determined based on the weight-average molecular weight M of the cellulose ether matrix material W ; wherein R 4 is an alkyl group having 16 carbon atoms, and wherein each R 5 is independently selected from C 1-7 alkyl groups (preferably, C 1-4 alkyl groups; more preferably, methyl and ethyl groups; most preferably, methyl group); and wherein the cellulose ether matrix material has a weight-average molecular weight M of > 1,000,000 daltons (preferably, 1,100,000 daltons to 4,000,000 daltons; more preferably, 1,200,000 daltons to 2,000,000 daltons; most preferably, 1,300,000 daltons to 1,800,000 daltons) W ; and wherein the modified carbohydrate polymer comprises < 0.001 wt% (preferably, < 0.0001 wt%; more preferably, < 0.00001 wt%; most preferably, less than the limit of detection) of crosslinked units based on the weight of the modified carbohydrate polymer.

[0032] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention is selected from rinse-off hair treatment agents and leave-in hair treatment agents. More preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention is a leave-in hair treatment agent.

[0033] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention optionally further comprises at least one additional ingredient selected from the following: cosmetically acceptable cleansing surfactants; thickeners (e.g., polysaccharides, cellulose polymers); soaps; colorants; pH regulators; antioxidants (e.g., butylated hydroxytoluene); emollients (polyethylene glycol (C 7-20)Esters of fatty acids and glycerol - such as PEG - 7 glyceryl cocoate, PEG - 30 glyceryl cocoate, PEG - 12 glyceryl laurate, PEG - 20 glyceryl oleate); waxes; foaming agents; emulsifiers (such as a mixture of PEG - 100 stearate and glyceryl stearate); colorants; fragrances; chelating agents (such as disodium EDTA, tetrasodium EDTA, citric acid, lactic acid); antimicrobial agents / preservatives (such as, methylchloroisothiazolinone, phenoxyethanol, methylisothiazolinone, esters of p - benzoic acid, diazolidinyl urea and imidazolidinyl urea, benzoic acid, sorbic acid); bleaching agents; lubricants; sensory modifiers; sunscreen additives; vitamins; proteins / amino acids; plant extracts; natural ingredients; bioactive agents; anti - aging agents; pigments; acids; penetrants; antistatic agents; anti - frizz agents; antidandruff agents; hair curling / straightening agents; hair styling agents; hair oils; absorbents; hard particles; soft particles; conditioners (such as, guar hydroxypropyltrimonium chloride, PQ - 10, PQ - 7); slip agents; opacifying agents; pearlescent agents and salts. More preferably, the aqueous heat - protecting agent formulation prepared and used in the method of the present invention optionally further comprises at least one additional ingredient selected from the following: emulsifiers (such as a mixture of PEG - 100 stearate and glyceryl stearate); antimicrobial agents / preservatives (such as, methylchloroisothiazolinone, phenoxyethanol, methylisothiazolinone, esters of p - benzoic acid, diazolidinyl urea and imidazolidinyl urea, benzoic acid, sorbic acid); thickeners (such as, polysaccharides, cellulose polymers); and chelating agents (such as disodium EDTA, tetrasodium EDTA, citric acid, lactic acid). Most preferably, the aqueous heat - protecting agent formulation prepared and used in the method of the present invention optionally further comprises at least one additional ingredient selected from the following: an emulsifier mixture of a mixture of PEG - 100 stearate and glyceryl stearate; a hydroxyethylcellulose polymer thickener; a cetearyl alcohol emollient; a tetrasodium ethylenediaminetetraacetate chelating agent; and a mixture of preservatives of phenoxyethanol and methylisothiazolinone.

[0034] Preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention optionally further comprises an emulsifier. More preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises 0.01% to 80% by weight (more preferably, 0.1% to 5% by weight; still more preferably, 0.5% to 2% by weight, most preferably, 0.75% to 1.25% by weight) of an emulsifier based on the weight of the aqueous heat protection agent preparation. Most preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises 0.01% to 80% by weight (more preferably, 0.1% to 5% by weight; still more preferably, 0.5% to 2% by weight, most preferably, 0.75% to 1.25% by weight) of an emulsifier based on the weight of the aqueous heat protection agent preparation; wherein the aqueous conditioning agent preparation is selected from leave-on hair conditioners and rinse-off hair conditioners; and wherein the emulsifier comprises a mixture of PET-100 stearate and glyceryl stearate.

[0035] Preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention optionally further comprises a thickener. More preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises a thickener, wherein the thickener is selected to increase the viscosity of the aqueous conditioning agent preparation, preferably without substantially changing other properties of the personal care composition. Still more preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises a thickener, wherein the thickener is selected to increase the viscosity of the personal care composition, preferably without substantially changing other properties of the personal care composition, and wherein the thickener accounts for 0% to 5.0% by weight (preferably, 0.1% to 5.0% by weight; more preferably, 0.2% to 2.5% by weight; most preferably, 0.5% to 2.0% by weight) based on the weight of the aqueous heat protection agent preparation. Preferred thickeners include polysaccharides and cellulose polymers. Preferably, the thickener is a hydroxyethyl cellulose polymer.

[0036] Preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention optionally further comprises a chelating agent. More preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises 0.001% to 0.75% by weight (preferably, 0.03% to 0.25% by weight) of a chelating agent based on the weight of the aqueous heat protection agent preparation, wherein the chelating agent is selected from disodium ethylenediaminetetraacetate (EDTA), EDTA tetrasodium, citric acid, lactic acid, and mixtures thereof. Most preferably, the aqueous heat protection agent preparation prepared and used in the method of the present invention further comprises 0.001% to 0.75% by weight (preferably, 0.03% to 0.25% by weight) of a chelating agent based on the weight of the aqueous heat protection agent preparation, wherein the chelating agent, wherein the chelating agent comprises EDTA tetrasodium.

[0037] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention optionally further comprises an antimicrobial agent / preservative. More preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention further comprises 0.05% to 1.25% by weight (preferably, 0.1% to 1% by weight; more preferably, 0.25% to 0.75% by weight) of an antimicrobial agent / preservative based on the weight of the aqueous heat protection agent formulation; wherein the antimicrobial agent / preservative is selected from phenoxyethanol, benzoic acid, benzyl alcohol, sodium benzoate, DMDM hydantoin, 2-ethylhexyl glycerin ether, isothiazolinones (e.g., methylchloroisothiazolinone, methylisothiazolinone) and mixtures thereof. Most preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention optionally further comprises 0.05% to 1.25% by weight (preferably, 0.1% to 1% by weight; more preferably, 0.25% to 0.75% by weight) of an antimicrobial agent / preservative based on the weight of the aqueous heat protection agent formulation; wherein the antimicrobial agent / preservative is a mixture of phenoxyethanol and isothiazolinone (more preferably, wherein the antimicrobial agent / preservative is a mixture of phenoxyethanol and methylisothiazolinone).

[0038] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of monosaccharides having amine groups.

[0039] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of C 3-5 monosaccharides.

[0040] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of sugars.

[0041] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of soy protein.

[0042] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of hydrolyzed silk protein.

[0043] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < detectable limit of sugars.

[0044] Preferably, the aqueous heat protection agent formulation prepared and used in the method of the present invention contains < 0.1% by weight (preferably, < 0.01% by weight; more preferably, < 0.001% by weight; most preferably, < detectable limit) of hydrophobically modified poly(acrylamido-N-propyltrimethylammonium chloride).

[0045] Preferably, in the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention, a known processing technique is used to combine the provided heat protectant formulation, a cosmetically acceptable aqueous carrier, and any additional ingredients to provide an aqueous heat protectant formulation. More preferably, in the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention, a known processing technique is used to combine the provided heat protectant formulation, a cosmetically acceptable aqueous carrier, and any additional ingredients to provide an aqueous heat protectant formulation; wherein the aqueous heat protectant formulation comprises from 25% to 99.95% by weight (preferably from 50% to 99.9% by weight; more preferably from 75% to 99.5% by weight; most preferably from 80% to 99.3% by weight) of a cosmetically acceptable aqueous carrier based on the weight of the aqueous heat protectant formulation; and from 0.1% to 5% by weight (preferably from 0.15% to 2.5% by weight; more preferably from 0.2% to 2% by weight; most preferably from 0.25% to 1.5% by weight) of a heat protectant based on the weight of the aqueous heat protectant formulation.

[0046] Preferably, in the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention, a well-known technique is used to apply the aqueous heat protectant formulation to the hair. More preferably, in the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention, the aqueous heat protectant formulation is applied to the hair, wherein from 0.01 g to 5 g of the aqueous heat protectant formulation is applied per g of hair.

[0047] Preferably, in the method of reducing hair damage upon exposure of hair (preferably mammalian hair; more preferably human hair) to heating according to the present invention, a heat-generating hair care appliance is provided. Heat-generating hair care appliances generally fall into one of two main categories, namely (1) heat-generating hair care appliances preferably used on wet hair (e.g., hair dryers) and (2) heat-generating hair care appliances preferably used on dry hair (e.g., straightening / curling with a hair straightening iron; hot rollers).

[0048] Heaters designed for use on wet hair and typically used on wet hair are sometimes referred to as hot air hair care appliances. Examples of hot air hair care appliances include hair dryers and hot air styling devices. A typical hair dryer is designed to direct hot air towards the hair to facilitate drying of the hair. In such hair dryers, air is directed through suitable apertures and accelerated by a fan. The air discharged by such hair dryers can be heated, for example, by using a resistive heater. A hair dryer may include a hood, with the main portion of the hair being covered by the hood. Hair dryers typically operate by delivering a hot air temperature of 50 °C to 100 °C. A hot air styling device typically directs hot air through an attachment designed to comb or otherwise manipulate the hair. A hot air styling device can deliver a hot air temperature of up to 130 °C.

[0049] Heaters designed for use on dry hair and typically used on dry hair are sometimes referred to as hot surface hair care appliances. Examples of hot surface hair care appliances can be designed for hair curling and / or hair straightening. Hot surface hair care appliances typically rely on resistive heating, where heat is transferred to the hair by direct contact with the appliance rather than by using hot air. Heat transfer is typically achieved by bringing the hair into contact with the metal or ceramic surface of the hot surface hair care appliance. Hot surface hair care appliances are not typically used to dry the hair. Instead, hot surface hair care appliances are used to change the styling of the hair, typically creating curls in the hair or straightening the hair. The surface of a hot surface hair care appliance designed to contact the hair and transfer heat to the hair typically reaches a temperature of 130 °C to 300 °C.

[0050] Preferably, in the method of reducing hair damage when exposing hair (preferably mammalian hair; more preferably human hair) to heating in the present invention, it includes using a heat-generating hair care appliance (wherein the heat-generating hair care appliance is selected from at least one of a hot air hair care appliance (e.g., hair dryer, hot air styling tool) and a hot surface hair care appliance (e.g., hot curler, straightening iron, and curling iron)) to expose the hair to heating at a temperature of 50°C to 300°C (preferably 80°C to 280°C; more preferably 90°C to 275°C; most preferably 100°C to 250°C) (e.g., for drying the hair or styling the hair). More preferably, in the method of reducing hair damage when exposing hair (preferably mammalian hair; more preferably human hair) to heating in the present invention, it includes using a heat-generating hair care appliance (wherein the heat-generating hair care appliance is selected from at least one of a hot air hair care appliance (e.g., hair dryer, hot air styling tool) and a hot surface hair care appliance (e.g., hot curler, straightening iron, and curling iron)) to expose the hair to heating at a temperature of 50°C to 300°C (preferably 80°C to 280°C; more preferably 90°C to 275°C; most preferably 100°C to 250°C) for 1 minute to 40 minutes (e.g., for drying the hair or styling the hair). Most preferably, in the method of reducing hair damage when exposing hair (preferably mammalian hair; more preferably human hair) to heating in the present invention, it includes using a heat-generating hair care appliance (wherein the heat-generating hair care appliance is selected from at least one of a hot air hair care appliance (e.g., hair dryer, hot air styling tool) and a hot surface hair care appliance (e.g., hot curler, straightening iron, and curling iron)) to expose the hair to heating at a temperature of 50°C to 300°C (preferably 80°C to 280°C; more preferably 90°C to 275°C; most preferably 100°C to 250°C) for 2 minutes to 40 minutes (e.g., for drying the hair or styling the hair); wherein the hair is exposed to heating for 1 minute to 20 minutes using a hot air hair care appliance to dry the hair; and then the hair is exposed to heating for 1 minute to 20 minutes using a hot surface hair care appliance to style the hair.

[0051] Preferably, in the method of reducing hair damage in the present invention when hair (preferably mammalian hair; more preferably human hair) is exposed to heating, optionally further comprising rinsing the hair with water. More preferably, in the method of reducing hair damage in the present invention when hair (preferably mammalian hair; more preferably human hair) is exposed to heating, optionally further comprising rinsing the hair with water (preferably for 30 seconds to 20 minutes (more preferably 30 seconds to 5 minutes)) before applying an aqueous protective agent formulation to the hair. Most preferably, in the method of reducing hair damage in the present invention when hair (preferably mammalian hair; more preferably human hair) is exposed to heating, optionally further comprising rinsing the hair with water (preferably for 30 seconds to 20 minutes (more preferably 30 seconds to 5 minutes)) before applying an aqueous protective agent formulation to the hair; and then drying the rinsed hair by at least one of blotting and squeezing the hair with a towel to remove excess water before applying the aqueous protective agent formulation to the hair.

[0052] Preferably, in the method of reducing hair damage in the present invention when hair (preferably mammalian hair; more preferably human hair) is exposed to heating, optionally further comprising at least one of combing and brushing the hair. More preferably, in the method of reducing hair damage in the present invention when hair (preferably mammalian hair; more preferably human hair) is exposed to heating, optionally further comprising at least one of combing and brushing the hair (preferably combing and / or brushing the hair before, during, and / or after exposing the hair to heating from a heated hair care appliance) after applying an aqueous heat protective agent formulation.

[0053] Some embodiments of the present invention will now be described in detail in the following examples.

[0054] Example S1: Thermal protection agent

[0055] Charge a 2,000 mL three-neck round-bottom flask with a mixture of 2-propanol (673.92 g) and deionized water (120.52 g) and a hydrophobically modified hydroxyethylcellulose polymer (hmHEC) (90.20 g, EMBARK TM Rheology Modifier 160) available from The Dow Chemical Company. The flask is equipped with a stir paddle and motor, a rubber serum cap, a nitrogen inlet, and a Claisen adapter equipped with a subsurface thermocouple and a Friedrich condenser with a mineral oil bubbler. The thermocouple is connected to a J-KEM controller and a heating mantle.

[0056] While stirring the contents of the flask, the flask was slowly purged with nitrogen for one hour to remove any entrained oxygen. A nitrogen flow rate of approximately 1 bubble / second was used. After the nitrogen purge was complete, 25% aqueous sodium hydroxide solution (9.60 g) was added to the flask contents through the serum cap using a plastic syringe while continuously stirring under nitrogen. The flask contents were then stirred under nitrogen for 30 minutes.

[0057] Then, using a plastic syringe, 70% aqueous glycidyltrimethylammonium chloride (60.48 g, available under the trade name 151 purchased from QUAB Chemicals) was added dropwise to the flask contents over a few minutes while stirring under nitrogen. When the addition was complete, the flask contents were stirred for 5 minutes, and then heat was applied to the flask contents using a J-KEM controller. The temperature set point was 55 °C, and the flask contents were heated at 55 °C for 1.5 hours while stirring under nitrogen.

[0058] The flask contents were then cooled to room temperature while maintaining a positive nitrogen pressure in the flask. The flask contents were then neutralized by adding glacial acetic acid (10.0 g) via syringe. After stirring for 10 minutes, the product heat protectant was recovered by vacuum filtration through a metal sintered Büchner funnel. The heat protectant was washed once in the Büchner funnel with each of the following: a mixture of 2-propanol (656 g) and deionized water (144 g); a mixture of 2-propanol (720 g) and deionized water (80 g); and 2-propanol (800 g), 40% glyoxal (1.76 g), and glacial acetic acid (0.60 g). The heat protectant was air dried briefly and then dried under vacuum at 50 °C overnight.

[0059] The heat protectant was manually ground using a mortar and pestle and sieved through a #30 mesh U.S. Standard sieve to obtain 100.22 g of product. The heat protectant had a volatile content of 4.41%, an ash content of 2.70% (as sodium acetate), and a Kjeldahl nitrogen content of 1.844%.

[0060] Comparative Examples C1 - C4 and Example 1: Thermal protection

[0061] Thermal damage procedure

[0062] The hair bundles (2g, slightly bleached Caucasian hair bundles available from International Hair Importers) were wetted in distilled water at 37 °C for 30 seconds, then 1.5 g of a 9 wt% sodium lauryl polyoxyethylene ether sulfate (SLES) solution was massaged into the hair, and then rinsed with water flowing at 0.4 L / min for 30 seconds; combed with a brush; and then finally rinsed with water flowing at 0.4 L / min for 10 seconds. Then the hair bundles were treated by applying and incorporating 100 μL / g of an aqueous treatment solution of the active substance shown in Table 1 (if any) into the hair bundles. Before the heat treatment of the hair bundles, the straightening iron was preheated to 232 °C. Then the hair bundles were treated ten times, with each treatment using the straightening iron for ten seconds. After that, the hair bundles were washed with a 9 wt% SLES solution, and this heat treatment and washing of the hair bundles were repeated three times before performing the following DSC study.

[0063] Table 1

[0064]

[0065] DSC study

[0066] Samples were prepared from the hair bundles treated according to each of Comparative Examples C1 - C4 and Example 1 by separating at least two different locks of hair from each hair bundle and trimming them into small pieces (<2 mm long) using trimming tools. The entire length of the selected hair locks was chopped and randomly distributed on weighing paper so that any differences in hair properties along the length of the hair bundle were evenly distributed. Then 10 mg samples were taken from each pile of small hair pieces using forceps. The samples were placed in separate 40 μL stainless steel pans (Perkin - Elmer part number 0319 - 0218) and evenly distributed on the bottom of the pans. 30 μL of deionized water was added to each pan using a pipette, and the deionized water plasticized the cuticle and lowered the hair denaturation temperature to below the decomposition temperature. Then the pans were pressed and sealed with Viton O - rings and stainless steel lids, and the total initial mass was weighed. To equilibrate the hair samples at the hydration level, the sealed pans were left to stand at 25 °C for 12 hours. Then the hair samples were analyzed by a differential scanning calorimeter (DSC) paired with a refrigerated cooling system (RCS90) unit. The hair samples were analyzed by equilibrating at 40 °C and then heating the samples at a heating rate of 10 °C / min to 200 °C. During the analysis, the unit flow rate was 25 mL / min of nitrogen. Instrument software (TRIOS) was used to determine both the denaturation temperature and the denaturation enthalpy. The denaturation temperature was determined as the peak temperature of the endothermic transition, and the denaturation enthalpy was determined by integrating the endothermic transition. The peak temperatures of the DSC curves are reported in Table 2. The denaturation enthalpies of the hair samples are also reported in Table 2.

[0067] Table 2

[0068]

Claims

1. A method for reducing damage to hair when the hair is exposed to heating, the method comprising: providing a cosmetically acceptable aqueous carrier; selecting a heat protectant, wherein the heat protectant is selected based on its ability to confer heat protection to the hair against exposure to heating, and wherein the heat protectant is selected as a modified carbohydrate polymer, the modified carbohydrate polymer comprising a cellulose ether matrix material functionalized with: (i) a trialkylammonium moiety of formula (I) where each R 1 is independently selected from C 1-7 alkyl groups, and wherein the modified carbohydrate polymer has a Kjeldahl nitrogen content TKN corrected for ash and volatiles of from 0.75% to 2.5% by weight; and (ii) a hydrophobic substituent having 16 carbon atoms each; wherein the modified carbohydrate polymer comprises 0.005% to 1.5% by weight of the hydrophobic substituent based on the weight of the cellulose ether matrix material; wherein the hydrophobic substituent is randomly distributed on the main chain of the cellulose ether matrix material; wherein the cellulose ether matrix material has a weight average molecular weight M of > 1,000,000 daltons W ; and wherein the modified carbohydrate polymer comprises < 0.001% by weight of crosslinked units based on the weight of the modified carbohydrate polymer; providing the selected heat protectant; combining the cosmetically acceptable aqueous carrier and the heat protectant to form an aqueous heat protectant formulation; wherein the aqueous heat protectant formulation contains 0.1% to 5% by weight of the heat protectant based on the weight of the aqueous heat protectant formulation; providing hair; applying the aqueous heat protectant formulation to the hair; providing a heated hair care appliance; and using the heated hair care appliance to expose the hair to heating at a temperature of 50°C to 300°C for 1 minute to 30 minutes.

2. The method according to claim 1, wherein the hair to which the aqueous heat protectant formulation has been applied exhibits a higher denaturation temperature than hair similarly exposed to heating but not applied with the aqueous heat protectant formulation.

3. The method according to claim 2, wherein the hair to which the aqueous heat protectant formulation has been applied exhibits a higher denaturation enthalpy than hair similarly exposed to heating but not applied with the aqueous heat protectant formulation.

4. The method according to claim 3, the method further comprising: rinsing the hair with water before applying the aqueous heat protectant formulation to the hair.

5. The method according to claim 4, the method further comprising: drying the rinsed hair by at least one of blotting and squeezing the hair with a towel to remove excess water before applying the aqueous heat protectant formulation to the hair.

6. The method according to claim 3, the method further comprising: combing and brushing the hair at least one of after applying the aqueous heat protectant formulation.

7. The method according to claim 3, wherein the aqueous heat protectant formulation applied to the hair further comprises a thickening agent.

8. The method according to claim 7, wherein the thickening agent is a polysaccharide.

9. The method according to claim 3, wherein the hydrophobic substituents of the selected heat protectant are bonded to the cellulose ether matrix material through ether bonds or ether bonds and 2-hydroxypropyl groups.

10. The method according to claim 9, wherein the aqueous heat protectant formulation further comprises an additive selected from the group consisting of chelating agents, preservatives, emollients, cosmetically acceptable cleansing surfactants, and mixtures thereof.

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