WO2021239622A1

WO2021239622A1 - Branched amino-acid-based polymers for hair strengthening

Info

Publication number: WO2021239622A1
Application number: PCT/EP2021/063676
Authority: WO
Inventors: Catherine Weichold; Monika Barbenheim; Daniela Prinz; Björn KLOTZ; Anja MOERSEBURG; Sandra Marten; Melanie HESSEL-WAGNER
Original assignee: Basf Se
Priority date: 2020-05-27
Filing date: 2021-05-21
Publication date: 2021-12-02

Abstract

The present invention relates to the use of a branched polylysine or of a branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, wherein these substituents are selected from the group consisting of acyl groups having 6 to 24 C-atoms, substituents having the formula -CH₂-CH(OH)-R or the formula -CHR-CH₂(OH), wherein R is an alky moiety with 2 to 20 C-atoms, substituents having the formula -C(=0)-NH-R, wherein R is an alky moiety with 2 to 20 C- atoms, substituents of the formula -CH₂-CH₂-C(=O)OR¹ wherein R¹ is an alkyl group having 6 to 24 C-atoms, and mixtures thereof, for reducing hair breakage of hair treated by chemical treatments, especially by bleaching, or by heat or by UV-radiation.

Description

Branched amino-acid-based polymers for hair strengthening The present invention relates to the use of a branched polylysine or of a branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, wherein these substituents are selected from the group consisting of acyl groups having 6 to 24 C-atoms, substituents having the formula -CH2- CH(OH)-R or the formula -CHR-CH2(OH), wherein R is an alky moiety with 2 to 20 C-atoms, substituents having the formula -C(=O)-NH-R, wherein R is an alky moiety with 2 to 20 C- atoms, substituents of the formula -CH2-CH2-C(=O)OR¹, wherein R¹ is an alkyl group having 6 to 24 C-atoms, and mixtures thereof, for reducing hair breakage of hair treated by chemical treatments, especially by bleaching, or by heat or by UV-radiation. The surface of hair, especially of human hair, can be damaged by hair treatment, e. g. by bleaching and other chemical treatments, by heat treatments and UV-irradiation. This leads not only to more hair breakage, but also to a matt appearance of the hair. Therefore, there is a need for substances that are able to decrease the negative effects of hair treatments, in particular chemical treatments. Methods to measure the degree of chemical hair damage usually often spectrophotometric (S.S. Sandhu, R. Ramachandran, C.R. Robbins, J. Soc. Cosmet. Chem., 1995, 46, 39-52; R. Pires-Oliveira, I. Joekes, Coll. Surf. B: Biointerfaces, 2014, 123, 326-330), with further methods being differential scanning calorimetry (T. Gao, A. Bedell, J. Cosm. Science, 2001, 52 (5), 332- 333; C. Popescu, C. Gummer, Int. J. Cosm. Science, 2016, 38 (5), 433-439), and gas porosity (Y.Z. Hessefort, B.T. Holland, R.W. Cloud, J. Cosm. Science, 2008, 59 (4), 303-315). In addition, hair breakage measurements are also suitable, as they are a measure of hair strength and are closely related to consumer observations. Problems connected with these options are either a low level of naturalness and / or effectiveness. The ‘litmus test’ is preserving the hairs’ strength during a chemical treatment. In h f ll i k l f f h f h i i li K n C e c s n

extracts from Bulgarian rose, Merquat 2220 and

Often hair damage is claimed to be repaired or prevented by using hair conditioning formulations (these are virtually always used as a final step of chemical hair treatments), or by high concentrations of proteins such as keratin. Many other individual ingredients are claimed to protect or repair hair damage, however, the effects are usually significantly less than when conditioning treatments are used. A more recent example is the use of a bismaleate binding agent (EP3001809 B1 and EP3142637) to repair disulfide bonds in hair, which are broken during chemical hair treatments. It is claimed that the broken disulfide bonds are ‘reconnected’ with a charged bisamine.

Lysine is an amino acid. There are two enantiomers of lysine, L-lysine and D-lysine. Lysine has two amino groups, one at the alpha-position, one at the epsilon-position. Linear L- polylysine is produced by natural fermentation and it is referred to as epsilon-Polylysine or 8- Polylysine. This fermentation can be carried out with bacteria strains of the genus Streptomyces, e. g. Streptomyces albulus.

Branched polylysine is formed when both amino-groups of lysine (alpha and epsilon) react in a polycondensation reaction with the carboxylic acid group of lysine.

WO 2007/060119, US 201/0123148, and WO 2016/062578 disclose a process for making branched polylysine. Derivatives of branched polylysine are also disclosed. Inter alia, polylysine reacted with saturated or unsaturated long-chain carboxylic acids is disclosed (WO 2016/062578, page 9, lines 29 to 30).

WO 2013/013889 discloses the use of hyperbranched polylysine as shale inhibitor.

The use of linear (not branched) polylysine in hair care applications is known.

EP 2036536 A1 discloses the use of polyamines in conditioning applications (hair care (curly hair) and antifrizz application), polylysine is mentioned.

EP 1 563 826 A1 describes the use of polylysine in spray applications (having a conditioner effect).

JP 62221616 describes the use of polylysine in hair cosmetic applications having a conditioning effect. The material obtained by bacteria is linear and in epsilon form. JP 2007169192 and JP 2007153791 describe hair cosmetics and shampoo formulations respectively with polylysine or its salt in combination with quaternized amines, again for conditioning applications.

WO 2015/128566 describes a treatment which consists in the application of polyamines (polylysine is mentioned) to keratin fibers and thereafter the application of an activated ester to the creatine fibers. Repair effects are mentioned.

US 20090074700 describes the use of polyamines (polylysine is mentioned) together with acids and insoluble material to impart shine on hair.

WO 2019/175041 discloses the use of a branched polylysine or of a branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, for bringing about a hair repair effect.

Parameters to characterize branched polylysine (apart from the differentiation between L- and D-lysine) are the average molar mass, either the number average Mn or the weight average Mw, the polydispersity PD = Mw/Mn (measured via gel permeation chromatography), the degree of branching, and the amine number. These parameters can be determined by methods known in the art and/or as disclosed in WO 2016/062578. In general, it is assumed that the backbone of branched polylysine as well as the side chains of branched polylysine both have amide groups formed by alpha-amino groups and by epsilon amino-groups. The relative amount of alpha- and epsilon amide groups in the backbone and in the side chains is not known.

The problem underlying the present invention is to provide a substance or a composition suitable for reducing hair breakage of hair treated by chemical treatments, especially by bleaching, or by heat or by UV-radiation

Preferably the said substance or composition should be fully sustainable, i. e. should not have the disadvantages of known substances or compositions.

This problem is solved by the use according to clam 1.

The subject-matters of the dependent claims are preferred embodiments of the present invention. “A composition suitable for treating hair” according to the present invention can be any composition suitable for treating hair. It can be a composition suitable for cleansing hair, especially a shampoo, it can be a composition for conditioning hair (a conditioner), it can be a mask.

In the branched polylysine according to the present invention and in the branched polylysine according to the present invention in which amino groups are derivatized the lysine repeating units can be derived from L-lysine or from D-lysine or from a mixture of L- and D-lysine, especially from a racemic mixture. Preferably these repeating units are derived from L-lysine.

The branched polylysine to be used according to the present invention and the branched polylysine to be used according to the present invention, in which amino groups are derivatized (in the latter case based on/calculated with respect to the polylysine framework, without derivatization) typically have the following properties:

• The number average of the molar mass Mn is 300 to 5000 g/mol.

• The weight average of the molar mass MW is 500 to 10000 g/mol, preferably 1000 to 5000 g/mol.

• The polydispersity PD (= Mw/Mn) is 1.2 to 4, preferably 1.2 to 3, more preferably 1.2 to 2.5

• The amine number is 350 to 600 mgKOH/g, preferably 350 to 500 mgKOH/g.

• The degree of branching DB is 0.15 to 0.5, preferably 0.2 to 0.35, more preferably 0.2 to 0.3.

The definition of amine number and of “degree of branching” DB can be found in the examples section of the present text.

The branched polylysine according to the present invention can be made by heating a mixture comprising lysine and water, especially as described in WO 2016/062578.

The branched polylysine in which 1 to 80 %, preferably 1 to 30 %, more preferably 1 to 20 %, and especially 4 to 10 %, of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, as it is defined in the claims of the present text, can be made by reacting branched polylysine with carboxylic acids, esters of carboxylic acids, anhydrides of carboxylic acids, epoxy compounds, isocyanates, or with compounds obtainable via Michael addition of amino groups to Michael donor fatty chains (e. g. acrylates or methacrylates). Typically, the branched polylysine, in which 1 to 80 %, preferably 1 to 30 %, more preferably 1 to 20 %, and especially 4 to 10 %, of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, as it is defined in the claims of the present text, has the following properties:

• The number average of the molar mass Mn is 300 to 5000 g/mol.

• The amine number is 350 to 600 mgKOH/g, preferably 350 to 500 mgKOH/g.

According to the present invention the surfactant can be any surfactant. It can be selected from the group consisting of an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, and mixtures thereof. The surfactants according to the present invention can be selected amongst the surfactants described in US 2017/0333734 (BASF internal reference PF 77681 US02) in paragraphs [0029] to [0032],

Further cosmetically acceptable ingredients different from the branched polylysine, different from the branched polylysine in which amino groups are derivatized, and different from the surfactant, can be any cosmetically acceptable ingredients known to the person skilled in the art. These further cosmetically acceptable ingredients can be selected amongst the ingredients described in US 2017/0333734 (BASF internal reference PF 77681 US02) in paragraphs [0033] to [0066],

Description of the figures:

Fig. 1 is a comparison on hair (wet) of two products (2019-66-2 vs. 2019-66-3) with n=11. Each line shows a pairwise comparison in a variable (median & weighted dev.). Filled symbol: Wilcoxon test. Significance level: not significant (●), significance ³ 90% (A), significance ³ 95% (¨), significance ³ 99% (■). Empty symbol signifies lower 90%-confidence bound (l.c.b.) for zero values. Square (□): l.c.b. > 0,66667; Circle (o): l.c.b. < 0,66667. Fig. 2 is a comparison on hair (dry) of two products (2019-66-2 vs. 2019-66-3) with n=11. Each line shows a pairwise comparison in a variable (median & weighted dev.). Filled symbol: Wilcoxon test. Significance level: not significant (●), significance ³ 90% (A), significance ≥ 95% (♦), significance > 99% (■). Empty symbol signifies lower 90%-confidence bound (l.c.b.) for zero values. Square (□): l.c.b. > 0,66667; Circle (o): l.c.b. < 0,66667.

Examples

Methods and Definitions

Concentrations

% means % by weight, unless defined differently.

Degree of Branching (DB)

The degree of branching (DB) of branched polylysine is defined according to H. Frey et al., Acta Polymer., 48, pages 30 to 35 (1997) as DB [%] = 100 x 2D/(2D+L) wherein D denotes the fraction of dendritic units and L denotes the fraction of linear units in the sample that is concerned.

DB was determined by ¹H NMR.

Amine Number

The amine number (unit: mg KOH/g), also referred to as amino number, was determined by titration. It was determined as described in WO 2016/062578 according to the formula given on page 13 of WO 2016/062578:

Calculation:

with

Amine number = Fraction of total amine, calculated as mg KOH/g V_P = Consumption of standard solution up to the inflection point [ml] V_B = Consumption of standard solution in blank value titration [ml] t = titer of the standard solution c = concentration of the standard solution [= 0.1 mol/f]

56.1 = molar weight of KOH [g/mol] E = weight of sample taken [g].

Average Molar Mass Mn (number average) and Mw (weight average)

Mn and Mw were determined by gel permeation chromatography as described in WO 2016/062578 (see page 12 of WO 2016/062578, wherein trifluoroacete means trifluoroacetic acid): M_w and M„were determined by size exclusion chromatography under the following conditions:

Solvent: 0.1% (w/w) trifluoroacetate, 0.1 M NaCI in distilled water Flow: 0.8 ml/min Injection volume: 100 pi

Column material: hydroxylated polymethacrylate (TSKgel G3000PWXL)

Calibration: poly(2-vinylpyridine) standards in the molar mass range from 839 to 1,020.000 g/mole (from PSS, Mainz, Germany)

Polydispersity

PD is defined as PD = Mw/Mn

Experiments Carried Out

Example 1 : branched polylysine 1

1700 g of a 50% aqueous solution of L-Lysine were placed in a 2I four-necked flask equipped with a stirrer a condensation column, a thermometer and a nitrogen inlet. The L-Lysine solution was heated to the boiling point. Then the temperature of the external heat source was increased according to the following profile: 1 h at 150 °C, 1h at 160, 1h at 170 and 1 h at 180°C while water was distilled off. The pressure was then decreased to 200 mbar while the external heat source was maintained at 180 °C and the reaction for circa 2 hours continued under vacuum (200 mbar). The warm reaction melt was collected in an aluminum vessel. At room temperature, a solid material was obtained.

The polymer was characterized by gel permeation chromatography, degree of branching and amino number:

Mn: 2070 g/mol Mw: 4070 g/mol PD: 2 degree of branching measured via ¹H-NMR = 0.3 amino number: 366 mgKOH/g Example 2: branched polylysine modified with oleic acid (modification of 10 % of the amino end groups with oleic acid)

50 g of branched polylysine, made according to the procedure described in example 3 (not dissolved in water) was melted at 120 °C and 10,25 g oleic acid were added under stirring. The pressure was then decreased to 200 mbar while the external heat source was maintained at 180°C and the reaction continued for circa 1 hour under vacuum (200 mbar). At room temperature, a solid material was obtained.

Example 3: branched polylysine modified with oleic acid (modification of 4.8 % of the amino end groups with oleic acid)

250 g of branched polylysine made according to the procedure described in example 2 (not dissolved in water) was melted at 120 °C and 26,37 g oleic acid were added under stirring. The pressure was then decreased to 200 mbar while the external heat source was maintained at 180°C and the reaction continued for circa 1 hour under vacuum (200 mbar). At room temperature, a solid material was obtained.

The polymer was characterized by gel permeation chromatography:

Mn: 1710 g/mol Mw: 2930 g/mol PD: 1.7

Application Examples

Hair breakage measurements

Preparation of hair strands for the hair breakage test

Ten hair strands (medium-dark brown Caucasian hair (12cm/1g) per sample were cleaned by incubation in 6% sodium lauryl ether sulfate at pH 6.5 for 15 minutes, followed by rinsing with water for three times two minutes. Finally, the hair strands were dried for 30 minutes hanging in a flow of warm air (approximately 55 °C).

The mixtures that were subsequently tested in the hair breakage test had the following composition (test substance and additive are specified in the following table):

0,8 g test substance

0,1 g additive

3,4 g demineralized water This mixture was blended with a 9% bleaching formulation (16.66 g Igora Vario Blond plus Schwarzkopf and 33.3 g Igora Royal Oil Developer Schwarzkopf 9% for the ten 1 g strands) and has a pH of 9 or higher. The hair strands were treated with the mixture, and after incubation for thirty minutes the strands were rinsed off for three minutes by hand. Afterwards, the hair strands were dried for one hour lying on a grid above a fan blowing with hot air. After preparation, the hair strands were equilibrated for at least five hours at 30 °C and 40% relative humidity.

Subsequently, the hair strands were combed 50,000 times (45rpm) at 30°C and 40% relative humidity. After 50,000 combing strokes, broken hair fibers were collected in drawers. Then fibers longer than the diameter of the petri dish (about 9cm) were sorted out, and the remaining fibers were weighed. Hair breakage is quantified as the ratio of the weight of broken fibers to the weight of the whole hair strand.

Results of hair breakage on ultra-bleached hair (10 hair strands):

The results show that treatment with branched polylysine oleate results in a strong reduction in hair breakage, which is superior to that of the listed benchmarks (entries 1-4). The effect of branched polylysine oleate is also significantly higher than that achieved with underivatized polylysine (entries 5-7). The addition of an organic acid, e.g. tartaric, maleic, adipic, succinic acid, has only a minimal effect on hair breakage reduction.

Sensorial comparisons (11 panelists):

Formulation 2019-66-2 Formulation 2019-66-3

36.6g Igora Vario Blond Schwarzkopf 36.6g Igora Vario Blond Schwarzkopf 73.3g Igora Royal Oil Developer Schwarzkopf 73.3g Igora Royal Oil Developer Schwarzkopf 1.8g branched polylysine oleate 2 9.5g market benchmark 0.2g tartaric acid 7.5g water

The results of the sensorial comparisons in the sensorial diagram (Fig. 1 and Fig. 2) confirm that formulations containing branched polylysine oleate are significantly superior to the market benchmark (formulation 2019-66-3), both for wet hair as well as dry hair. In combination with tartaric acid, significant benefits were observed while combing, also in terms of the softness / smoothness and the general acceptance. In addition, for dry hair the volume is positively impacted.

Claims

1. The use of a branched polylysine or of a branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized so that they bear one or two substituents, wherein these substituents are selected from the group consisting of

• acyl groups having 6 to 24 C-atoms,

• substituents having the formula -CH2-CH(OH)-R or the formula -CHR-CH₂COH), wherein R is an alky moiety with 2 to 20 C-atoms,

• substituents having the formula -C(=O)-NH-R, wherein R is an alky moiety with 2 to 20 C-atoms,

• substituents of the formula -CH₂-CH₂-C(=O)OR¹, wherein R¹ is an alkyl group having 6 to 24 C-atoms,

• and mixtures thereof, for reducing hair breakage of hair treated by chemical treatments, especially by bleaching, or by heat or by UV-radiation.

2. The use according to claim 1 , wherein the branched polylysine or the branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized, are comprised in a composition, wherein the composition further comprises at least one carboxylic acid, preferably a carboxylic acid selected from the group consisting of tartaric acid, maleic acid, adipic, succinic acid, sebacic acid, azelaic acid, and itaconic acid.

3. The use according to claim 1 or 2, wherein the branched polylysine or the branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized, are comprised in a composition, wherein the composition further comprises at least one surfactant selected from the group consisting of an anionic surfactant, a cationic surfactant, a nonionic surfactant, a zwitterionic surfactant, and mixtures thereof.

4. The use according to any of claims 1 to 3, wherein the composition further comprises one or more further cosmetically acceptable ingredients different from the branched polylysine, different from the branched polylysine, in which amino groups are derivatized, and different from the surfactant and different from the carboxylic acid.

5. The use according to any of claims 2 to 4, wherein the composition is a composition suitable for use in hair treatment, and wherein the composition has a pH of 9 or higher.

6. The use according to any of claims 2 to 5, wherein the composition comprises

0.1 to 10 % by weight, preferably 0.5 to 5 % by weight of the branched polylysine or of the branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized,

0.1 to 30 % by weight, preferably 1 to 25 % by weight of the surfactant,

0 to 0.5 % carboxylic acid, and

0 to 99.8 % by weight, preferably 0 to 98.5 % by weight of the one or more further cosmetically acceptable ingredients.

7. The use according to any of claims 1 to 6, wherein the hair is human hair.

8. The use according to any of claims 1 to 7, wherein a branched polylysine in which amino groups are derivatized is used, wherein the substituents are selected from the group consisting of

• acyl groups having 10 to 20 C-atoms, more preferably 18 C-atoms,

• substituents having the formula -CH₂-CH(OH)-R or the formula -CHR-CH₂(OH), wherein R is an alky moiety with 2 to 20 C-atoms,

• substituents of the formula -CH₂-CH₂-C(=O)0R\ wherein R¹ is an alkyl group having 6 to 24 C-atoms,

• substituents formed by the reaction of the amino groups present in the branched polylysine with polyisobuthylene succinic anhydride (PIBSA),

• and mixtures thereof.

9. The use according to claim 8, wherein the substituents are acyl groups having 6 to 24 C- atoms, preferably acyl groups having 10 to 20 C-atoms, more preferably 18 C-atoms.

10. The use according to claim 8 or 9, wherein 1 to 30 %, preferably 1 to 20 %, and especially 4 to 10 %, of the amino groups present in the branched polylysine are derivatized.

11. The use according to any of claims 8 to 10, wherein the substituents are acyl groups derived from oleic acid.

12. The use according to claim 1 , wherein this use comprises contacting the hair with the branched polylysine or with the branched polylysine, in which 1 to 80 % of the amino groups present in the branched polylysine are derivatized, and wherein this contacting is done in a composition that has a pH of 9 or higher.