Polymer for treating hair

Abstract

The present invention relates to a polymer comprising repeating units derived from at least one first monomer (monomer A) which is a molecule comprising a thiolactone ring and an ethylenically unsaturated, polymerizable double bond, and at least one second monomer (monomer B) which is N-vinyl pyrrolidone. Furthermore the present invention relates to a modified polymer, the structure of which is identical to the structure of the said polymer apart from the only difference, which is that all or at least some of the thiolactone moieties of the said polymer are modified by opening the thiolactone ring with a substance selected from the group consisting of ammonia, a primary amine, 2-amino-1-ethanol and L-lysine, wherein the N-atom of said substance is binding to the carbonyl group of the opened thiolactone ring. Furthermore, the present invention relates to a process for making the modified polymer and to the use of the polymer or of the modified polymer for treating hair.

Claims

1. A polymer comprising one first monomer which is N-homocysteine-thiolactone methacrylamide and one second monomer which is polyvinylpyrrolidone.

2. The polymer according to claim 1, wherein the amount of one first monomer in the polymer is 1 to 10 mol-% and wherein the amount of second monomer in the polymer is 90 to 99 mol-% and wherein the amount of monomer C in the polymer is 0 to 10 mol-% with respect to the sum of the molar amounts of monomers A and B.

3. The polymer according to claim 1 wherein the amount of one first monomer in the polymer is 2 to 8 mol-%.

4. The polymer according to claim 1 wherein the amount of one first monomer in the polymer is 3 to 7 mol-%.

5. The polymer according to claim 1 wherein the amount of the second monomer in the polymer is 92 to 98 mol-%.

6. The polymer according to claim 1 wherein the amount of the second monomer in the polymer is 93 to 97 mol-%.

Description

EXAMPLES

(1) N-homocysteine thiolactone methacrylamide was synthesized as described in “H. Kitano, H. Wolf, N. Ise, Macromolecules 1990, 23, 1958-1961.”

(2) Polymer Example 1: Synthesis of polyvinylpyrrolidone-N-homocysteine-thiolactone methacrylamide copolymer

(3) 400 g of 2-propanol were heated to 75° C. in a 2 liter reaction vessel, equipped with a stirrer and a condenser. 167.5 g N-vinylpyrrolidone and 12.5 g N-homocysteine thiolactone methacrylamide were dissolved in 150 g 2-propanol and constantly added to the preheated solvent within 4 hours. At the same time, 1.8 g of azobis-2-methyl-butyronitrile (Wako V59), dissolved in 100 g of 2-propanol, were constantly added within 4.5 h. Subsequently, the mixture was polymerized for another 2 hours and cooled down to room temperature. The product was subjected to steam distillation and stored in the form of an aqueous solution of 20 wt.-% at room temperature.

(4) Polymer Example 2: Reactive activation of polyvinylpyrrolidone-co-poly-N-homocysteine thiolactone methacrylamide by aminolysis and labeling with fluorescent dye.

(5) 5 g of polyvinylpyrrolidone-N-homocysteine-co-poly-N-homocysteine thiolactone methacrylamide were dissolved in 15 g of dimethyl sulfoxide in a 50 mL 3-neck-flask, equipped with a stirrer, condenser and a nitrogen connection and mixed with 1 g of 2-aminoethan-1-ol and 20 mg of tris(2-carboxyethyl)phosphine hydrochloride. The mixture was stirred under nitrogen atmosphere for 2 hours at room temperature. Subsequently, 200 mg of fluorescein-O-acrylate were added and the mixture was stirred for another 4 hours at 40° C. under exclusion of light. The fluorescently-labeled polymer was purified via dialysis and stored in aqueous solution under exclusion of light.

(6) Polymer Example 3 (a comparison example): Synthesis of fluorescently-labeled polyvinylpyrrolidone

(7) 209.5 g of N-vinylpyrrolidone, 0.5 g of ammonia and 790.86 g of water were heated to 75° C. in a 2 liter reaction vessel, equipped with a stirrer, a condenser and a nitrogen connection. In the meanwhile, 1.26 g of fluorescein-O-acrylate and 0.1 g of 2,2′-azobis(2,4-dimethylvaleronitrile) (Wako V65) were dissolved in 1.26 g acetone and added to the mixture at 50° C. The mixture was stirred for 1 hour under nitrogen flow when the temperature reached 70° C. The remaining initiator (0.1 g V65 in 1.26 g acetone) was added and the mixture was stirred for another hour. Finally, a last portion of 1.66 V65 in 4.88 g acetone was added and the mixture was stirred for another 30 minutes. Subsequently, the mixture was heated to 90° C. and further polymerized for 2 hours. 0.63 g of formic acid was added and the mixture was stirred for another 30 minutes before cooling down to room temperature. The pH was adjusted to 7 with ammonia and the polymer was purified via steam distillation. The final pH was adjusted to 8 with 25 wt.-% of sodium hydroxide solution.

(8) Application Examples

(9) For the following applications tests a “permanent lotion” with ammonium thioglycolate and a “fixation lotion” with hydrogen peroxide were used.

(10) Solution A (Permanent Lotion): water, ammonium thioglycolate, ammonium bicarbonate, butylene glycol, propylene glycol, PEG-35 castor oil, ethoxydiglycol, Coceth-10, carnitine HCL, perfume, Polyquarterium-6, ammonium hydroxide, Quarternium-80, benzyl salicylate, linalool, citronellol, alpha-isomethyl ionone

(11) Solution B (Fixation Lotion): water, hydrogen peroxide, propylene glycol, PEG-35 castor oil, Laureth-4, PEG-40 hydrogenated castor oil, Coco-Betaine, phosphoric acid, creatine, perfume, Polyquarternium-35, salicylic acid, Sodium Cocoamphoacetate, butylphenyl methylpropional, linalool, alpha-isomethyl ionone, tetrasodium pyrophosphate, benzoic acid

(12) Application Example 1: Binding of polymers to hair that was pre-treated with Solution A Solution A was applied on blond hair (3 blond hair strands) at room temperature and incubated for 10 min. The hair strands were rinsed under tap water and the towel dried strands were treated each with the following polymer solutions (i) Polymer Example 2 (ii) Polymer Example 3 (iii) no polymer, at room temperature. The hairs strands were kept for 2 h at 70° C. and then rinsed. The towel dry strands were treated with Solution B at room temperature and kept at room temperature for 10 min. Then the strands were rinsed under tap water and dried for 12 h at room temperature. All hair strands were tested with respect to wash fastness (10× washed with shampoo).

(13) Result: fluorescence spectroscopy pictures of all three hair strands were recorded. Only the thiol-containing polymer showed strong fluorescence after the wash fastness test proving the covalent and permanent modification of the hair surface.

(14) Application Example 2: Binding of polymers to hair that was not pre-treated with Solution A Application Example 1 was repeated without treatment with solution A and without treatment with solution B.

(15) Result: Identical results from fluorescence spectroscopy for of all three hair strands compared to application example 1.

(16) This result indicates that the polymer according to Polymer Example 2 binds covalently to hair even without Solution A and without Solution B.

(17) Apart from the evaluation with fluorescence spectroscopy the hair strands obtained in Application Examples 1 and 2 were also evaluated by colorimetric reflectance measurements. The results are summarized in the following table.

(18) The colorimetric reflectance measurements result in a dE* value which was determined according to EP2454328B1. The colorimetric reflectance measurements were conducted with the following spectrophotometer: “Datacolor Spectraflash SF 450” equipped with a xenon light source filtered to D65 with a measurement geometry of diffuse illumination and 8° viewing. The measurements of the hair tresses were conducted directly on the measure head using a plate with an aperture (hole) of 6.6 mm. The measurements were conducted 8 times and the average values were used. Before the measurements, the spectrophotometer was calibrated using a black and a white standard provided by Datacolor. The measurement was carried out as described in EP 2 454 328.

(19) The following table shows the results of color change compared to the hair strand (iii) of the application tests. A high number auf dE* shows a good washing fastness of the corresponding polymer and thus a permanent modification of the hair (this is the case for numbers 1 and 3).

(20) TABLE-US-00001 dE*-indicating washing fastness and thus covalent No. Example Hair type Polymer binding 1 Application Blond native Polymer 44.4 Example 1 Example 2 2 Application Blond native Polymer 3.21 Example 1 Example 3 3 Application Blond native No polymer 1.22 Example 1 treatment 4 Application Blond native Polymer 29.9 Example 2 Example 2 5 Application Blond native Polymer 9.0 Example 2 Example 3 6 Application Blond native No polymer 0.79 Example 2 treatment

(21) The colorimetric reflectance measurements confirm the results of the fluorescence spectroscopy measurements: the polymer according to Polymer Example 2 binds covalently to hair even without Solution A and without Solution B. The difference between the values 44.4 and 29.9 has no known significance.