CH628806A5 - Use of oxazolidines to improve the structure of damaged hair - Google Patents

Description

The invention relates to the use of oxazolidines for improving the structure of hair damaged, for example, by corrugation, bleaching or dyeing processes.

Cosmetic treatments that are carried out on human hair for fashion reasons are known to lead to damage to the hair structure in some cases. Treatments in which damage can occur to a greater or lesser extent include, for example, permanent waves, repeated cold curls, the bleaching and lightening process and the coloring process with oxidation dyes, in particular with simultaneous lightening. The damage to the hair manifests itself here a loss of natural shine, an unaesthetic dull appearance and, in the case of severe damage, by splitting the ends of the hair, breaking off the hair or even the appearance of bumps in the hair.

Attempts have been made to improve the structure of such damaged hair by treating it with various means, but no satisfactory solution has yet been found. Thus, according to German Patent Specification 1,148,039, low molecular weight formaldehyde precondensates of urea or thiourea are applied to the hair, which, through further condensation on the hair surface and possibly also in capillary spaces, also lead to film formation and hair strengthening. In this case, however, the structure of the damaged hair is not improved, but the damaged hair is only given more hold by a synthetic resin structure. Attempts have also been made to improve the properties of hair damaged by cosmetic treatment by treating it with agents which contain multiple aldehydes such as glycol dialdehyde, glyceraldehyde, glutardialdehyde and other aliphatic or aromatic polyaldehydes. The main disadvantage of such agents is that they can cause serious scalp irritation in sensitive individuals.

It has now been found that oxazolidines of the formula

R,

R,

r ~ f <o or

N - R <

R,

w °

(l)

Rj is hydrogen, an alkyl, a hydroxyalkyl or aminoalkyl group in which the alkyl chains contain 1-18 carbon atoms,

R2 and R3 are hydrogen, the hydroxymethyl radical or an alkyl radical with 1-18 carbon atoms, with the proviso that R2 and R3 are not simultaneously hydrogen,

represent, can be used with advantage to improve the structure of damaged hair.

The oxazolidines to be used according to the invention can be prepared from the corresponding β-hydroxyamines by condensation with formaldehyde by processes known from the literature, as described by E.D. Bergmann in Chemical Reviews 53, 309ff. (1953). The reaction proceeds as follows:

3rd

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R3 - CH CHR2

1

OH NHR

+ HCHO

-h20

R.

O N

'R® / r)

(F rozw, - R. '

H

CHp C ÇH2 + 2 HCHO>

OH NHg OH

-2H20

R

2nd

O N O

In these formulas, the radicals R ,, R2 and R3 have the aforementioned meaning.

The following compounds may be mentioned, for example, as oxazolidines to be used according to the invention:

4-methyl-oxazolidine, 5-methyl-oxazoiidine, 5-ethyl-oxazolidine, 5,5-dimethyl-oxazolidine, N-ethyl-5-hexyl-oxazolidine, 5-methyl-N- (2-hydroxypropyl ) -oxazolidine, 5-decyl-N- (2-hydroxyethyl) -oxazolidine, 5-octadecyl-N- (2-hydroxyethyl) -oxazolidine, 4-decyl-N- (2-hydroxyethyl) -oxazolidine, 5- Hydroxymethyl-oxazolidine, 4-hydroxymethyl-oxazolidine, N- (2 ~ aminoethyl) -5- (C9-C12-alkyl) -oxazolidine, N- (2-aminoethyl) -4- (C9-Ci2-alkyl) -oxazolidine, N- (2-aminoethyl) -4,5-di- (C9-Cj2-alkyl) -oxazolidine, N- (6-aminohexyl) -5-decyl-oxazolidine, 1-aza-3,7-dioxa-bicyclo- (3,3,0) -octane, 5-hydroxymethyl-l-aza-3,7-dioxa-bicyclo- (3,3,0) -octane, 5-decyl-l-aza-3,7-dioxabicyclo- (3,3,0) octane.

The use of the oxazolidines according to the invention is advantageously carried out in the form of an acidic aqueous-alcoholic solution, which can be applied to the hair after the permanent waving, cold waving, the bleaching or dyeing process before further treatment. Insofar as they are stable in an acidic environment, fixed and moisturizing substances can also be introduced into these acidic treatment solutions, which improve combability, for example. The pH of the acidic treatment solution containing the oxazolidines to be used according to the invention ranges, for example, between the values 2.5 to 6.5, preferably 2.5 to 4.0. The content of oxazolidines in the treatment solution is, for example, I to 10 percent by weight, preferably 2 to 7 percent by weight, based on the total solution.

The adjustment of the treatment solution to the desired pH can be done with the help of physiologically acceptable acids, such as. B. lactic acid, tartaric acid, ci-tronic acid. Ethanol or isopropanol is generally used as the alcoholic component of the aqueous-alcoholic solution.

The structure-improving agents are expediently packaged as a two-component pack, the one component generally being the acidic aqueous-alcoholic solution, including any strengthening and conditioning additives, and the second component being the oxazolidine compound. The two components can be combined before use to produce the ready-to-use treatment solution. With this solution, the damaged hair can be soaked and then dried with a hair dryer, with the use of the structure-improving treatment solution being the last treatment before styling in many cases.

The following examples are intended to explain the subject matter of the invention in more detail.

For example, some of the oxazolidines to be used according to the invention and their preparation are first described in more detail.

2o A. Preparation of the N-ethyl-5-hexyl-oxazolidine.

° 6h13-

,

0 ^ N

C2H5

121 g of 2-hydroxyoctylethylamine and 21.2 g of paraformaldehyde were boiled in 250 ml of xylene on a water separator until the calculated amount of water had been distilled off azeotropically, which had happened after about 6 hours. After the solvent had been distilled off, the crude product was subjected to fractional distillation. 120 g of N-ethyl-5-hexyl-oxazolidine were obtained, which corresponds to 92% of the theoretical yield. The connection had the following characteristics:

Bp 56 ° C / 0.01 mbar nD20 = 1.4442.

The following products were produced in an analogous manner using the appropriate starting materials.

40 B. 5-methyl-N- (2-hydroxypropyl) oxazolidine CH,

25th

30th

35

"1 1

45

O.

N

-CH2-CH0H

Bp 108 ° C / 37 mbar nD20 = 1.4553 yield 80% of theory

i

CH-

C. 5-Decyl-N- (2-hydroxyethyl) oxazolidine

C10H2V

'I!

O.

N -CH2-CH20H

60

65

Mp 29 ° C. Yield 55% of theory D. N- (2-aminoethyl) -4 (5) - (C9-C12-alkyl) -oxazolidine

(c9- ° 12)

c9 "° 12

1-1 "

Bp 135-142 ° C / 0.06 mbar nD20 yield 85% of theory

° ^^ N-CH2-ch2-NH2

I soraerengemi sch 1.4723

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E. N- (6-aminohexyl) -5-decyl-oxazolidine

C10H21-

r-1

(ch2) 6 ~ nh2

Mp 81-83: C, hygroscopic yield 24% of theory

F. 5-hydroxymethyl-1-aza-3,7-dioxabicyclo (3,3,0) octane

CHpOH \

(—I—!

Mp 54-55 ° C, commercial product

G. 5,5-dimethyl-oxazolidine

CH "

CH ".

, NH

commercial product

A so-called panel test was carried out to demonstrate the structure-improving effect. A group of 15 trained people checked and assessed the appearance, grip and combability of treated hair strands. The rating scale ranged from 0-10, with low numbers indicating bad, high numbers indicating good ratings. The following properties were tested in detail and evaluated as described below. The points 1-9 were between the two extremes.

score

score

0 dull, lackluster to

10th

high gloss, smooth

0 hard, bristly grip up to

10th

soft, silky, comfortable grip

0 difficult to comb,

to

10th

easy to comb, with lots of hair

no hair broken off

will

10th

25th

30th

■ "35

40

The strands of hair to be tested were damaged by bleaching and wave treatments. The degree of damage was reduced by inserted treatments with a solution of the structure-improving compound. The standard used was an untreated strand of brown, native hair, to which the rating grade 10 was assigned, and a strand of the same starting hair damaged by four bleaching and cold waves without treatment with structure-improving agent, which received the rating grade 0. The treatment was carried out as follows:

The lock of hair was bleached for 45 minutes at room temperature, then rinsed well with water at 40 ° C., then terry with the towel and dried with the hair dryer.

The bleaching was carried out with a mixture of the following composition:

First, a cream was made from the following ingredients:

Cetyl stearyl alcohol lauryl sulfate ammonium sulfate ammonia conc. water

11.0 parts by weight 12.0 parts by weight 1.0 part by weight 14.0 parts by weight 62.0 parts by weight

To prepare the bleaching mixture, 50 g of the cream were mixed with 50 g of a 6% by weight hydrogen peroxide solution and 14 g of ammonium peroxydisulfate.

The dry strand of hair was soaked with the acidic solution of oxazolidine to be examined for its effect, excess liquid was wiped out of the hair with a towel and then dried with a hair dryer.

A solution of 5 g of the corresponding oxazolidine in a mixture of 30 g of isopropanol and 65 g of water, which had been adjusted to a pH of 2.5 with lactic acid, was used for the treatment.

The bleached hair strand treated with the solution of the structure-improving compound was intensively wetted with a wave liquid for 30 minutes and then treated with a bromate-containing fixative mixture for 10 minutes. After thoroughly rinsing the hair, the hair dryer was used.

A 6% by weight thio-glycolic acid solution, which had been adjusted to a pH of 9.3 with ammonia, served as the corrugated liquid.

The fixing mixture had the following composition:

Potassium bromate 3.5 parts by weight

Tartaric acid 0.4 parts by weight

Water 96.1 parts by weight

Treatment with the solution of the structure-improving compound was then carried out again as described above. The procedures were repeated in the order described, until a total of 4 bleaching, 4 wavy and 8 treatment with the structure-improving compound solution. The comparison strand was subjected to the same bleaching and corrugating processes, but without the intermediate treatment with the solution of the structure-improving compound. After this overall treatment, the strands of hair were evaluated.

In the evaluation, the evaluation grades listed in Table 1 below were obtained, which each represent the mean of the 15 individual evaluations of the three properties tested and thus provide an overall picture of the structure-improving effect of the individual compound.

Table 1

60

65

connection

Assessment

grade

Untreated, native hair

10th

N-ethyl-5-hexyl-oxazolidine

9

5-methyl-N- (2-hydroxyethyl) -

9

oxazolidine

5-decyl-N- (2-hydroxyethyl) -

6

oxazolidine

N- (2-aminoethyl) -4 (5) -

7

(C9-C! 2-alkyl) oxazolidine

N- (6-aminohexyl) -5-decyl-

5

oxazolidine

5-hydroxymethyl-l-aza-3.7-

9

dioxabicyclo- (3,3,0) octane

5,5-dimethyl-oxazolidine

9

Without intermediate treatment with the

0

Solution to improve the structure

Bleached and wavy connection

5

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The table above shows that the compounds to be used according to the invention have considerable structure-improving properties, since the value 10 would mean that the hair damaged by the repeated bleaching and waving treatment is treated as untreated by the inserted treatment with the solution of the structure-improving compound Initial hairs behave.

For example, compositions for two-component treatment solutions for improving the structure of damaged hair are listed below:

Structure-improving composition

Component I: isopropanol 25.0 g

Perfume oil 0.3 g

Lactic acid 34.0 g

Water 35.7 g

95.0 g

Component II: 5-decyl-N- (2-hydroxy-5.0 ethyl) oxazolidine

The components are mixed well before use. The treatment solution has a pH of 2.5. Instead of lactic acid, tartaric acid, citric acid and other physiologically acceptable acids can be used to adjust the acidic pH. Instead of 5-decyl-N- (2-hydroxyethyl) oxazolidine, the other oxazolidines mentioned above can be used as structure-improving substances.

Structure-improving composition with a simultaneously strengthening effect

Component I: ethanol 25.0 g

10 perfume oils 0.3 g

Tartaric acid 7.0 g

Polyvinyl pyrrolidone 4.0 g

Water 58.7 g

Component II: N- (2-aminoethyl) -4 (5) - 5.0 g

(Cp-Cj 2-alkyl) oxazolidine

The components are mixed well before use. 20 The pH of the finished treatment solution is 2.5. In place of N- (2-aminoethyl) -4 (5) - (C9-Ci2-alkyl) -oxazolidine, all the other oxazolidines mentioned above and in place of tartaric acid, lactic acid, citric acid and other physiologically acceptable acids can be used to step.

s

Claims (5)

628 806 2nd PATENT CLAIMS 1. Use of oxazolidines of the formula R, "V y R, £ /} or- Ov N - R. 3rd Oil) in which R, hydrogen, an alkyl, a hydroxyalkyl or aminoalkyl group in which the alkyl chains contain 1-18 carbon atoms, R2 and R3 are hydrogen, the hydroxymethyl radical or an alkyl radical with 1-18 carbon atoms, with the proviso that R2 and R3 are not simultaneously hydrogen, represent, to improve the structure of damaged hair. 2. Use according to claim 1 in a treatment solution of pH 2.5 to 6.5, preferably 2.5 to 4.0. 3. Use according to claim 1 in a treatment solution in an amount of 1 to 10 weight percent, preferably 2 to 7 weight percent, based on the total solution. 4. Use according to claim 2 or 3 in an aqueous ethanolic or aqueous isopropanolic solution. 5. Use according to claim 2, wherein the treatment solution is acidified by lactic acid, tartaric acid or citric acid. 6. Use according to claim 1 in a treatment solution which further contains hair fixatives and / or conditioners.