CZ20003791A3 - A method of permanent hair shaping - Google Patents

Abstract

The subject of this solution is a method for permanent hair styling, in which the hair is mechanically shaped and treated with a keratin reducing agent, washed and fixed with an oxidizing agent, which has a particularly good styling effect. The styled hair shows increased durability and improved combability when a finely divided oil-in-water emulsion containing at least 1 wt. % of a water-soluble keratin reducing agent and at least 1 wt. % of an oil or fat component with a mean droplet size of less than 200 nm and less than 0.4 parts by weight of a hydrophilic emulsifier, based on 1 part by weight of the oil or fat component, is used as the reducing agent.

Description

Method of permanent hair styling

Technical field

The invention relates to a method of hair shaping by reductive cleavage and renewed oxidative bonding of disulfide compounds of hair keratin, in which a preparation in the form of a finely divided oil-in-water emulsion containing a limited amount of hydrophilic emulsifiers is used to perform keratin reduction.

State of the art

Hair styling products are essentially permanent waves and hair straightening products. Cold permanent waves contain a reducing agent that reduces the disulfide bonds of hair keratin to mercapto groups. This means that these can be strong alkalis, e.g. alkyl hydroxides, ammonia or alkanolamines, and other substances that cause keratin swelling, e.g. urea, guanidine or imidazole. Hair straightening products also contain a strong keratin swelling agent, usually in combination with keratin reducing agents. The hair can be styled before or after the treatment with this agent, e.g. by winding it on curlers. When some of the keratin disulfide bridges are then reconnected by mild oxidation, the styling is fixed.

However, the action of the keratin reducing agent is not fully reversible, but • ··· ·*· · · · · « • . · · » · · · *** ** ** ···· ·· ··· results in several undesirable side effects. Since not all disulfide compounds are restored, the duration of the hair shape (curi retention) is not optimal and the strength of the hair fiber is reduced. The attack on the so-called cuticle also causes the external scaly appearance of the hair and the fact that the hair is rough and difficult to comb and dull to the touch.

Therefore, the task arose to correctly formulate a permanent wave preparation that would reduce unwanted side effects as much as possible.

This can be achieved, for example, by adding a hair swelling agent to loosen the hair structure, allowing the active chemicals to penetrate the hair more quickly. Another option that increases the effectiveness of the active chemicals is a galenic formulation, e.g. according to WO-A-94/24987, such as a microemulsion. However, this requires a relatively high dose of hydrophilic surfactants, which can contribute to skin irritation.

It has now been discovered that finely divided emulsions obtained by the phase inversion process with a mean droplet size of less than 200 nm, which can be obtained with a limited amount of hydrophilic emulsifiers, are surprisingly suitable as carriers for hair styling agents and have a particularly favorable effect on the properties of the styled hair.

The essence of the invention

The subject of the invention is therefore a method of permanent hair styling, in which the hair is treated with a keratin reducing agent before and after mechanical styling, rinsed and fixed with an oxidizing agent, and in which a finely divided emulsion of the type is used to reduce keratin

- 3 • «···· · · · * * · • · · · · · · · · · · · · · · · · · · · · · · · · · · oil in water containing at least 1 wt.% of a water-soluble keratin reducing agent and at least 1 wt.% of an emulsified oil or fat component with a mean droplet size of less than 200 nm and less than 0.4 parts by weight of a hydrophilic emulsifier, based on 1 part by weight of the oil or fat component.

As water-soluble keratin reducing agents, keratin reducing agents selected from the group of mercapto compounds, phosphines and sulphites are used. Suitable mercapto compounds are water-soluble salts of mercaptocarboxylic acids with 2-4 carbon atoms, such as thioglycolic acids and thiolactic acids, i.e., ammonium thioglycolate, monoethanolamine thioglycolate or the corresponding thiolactates, as well as cysteine and cysteamine.

Suitable sulfites are preferably alkaline, ammonium and akanolammonium salts of sulfurous and disulfuric acids, e.g. sodium sulfite (Na ₂ SO 3 ) or sodium metabisulfite (Na ₂ S ₂ O ₅ ).

Preferably, keratin reducing agents, which contain 1-20 wt.% of keratin reducing substance, are selected from the group of mercapto compounds, phosphines or sulfites.

Another object of the invention is a means for carrying out the keratin reduction step in a method of permanent hair styling in the form of a finely divided oil-in-water emulsion containing at least 1 wt.% of a water-soluble keratin reducing agent and at least 1 wt.% of an emulsified oil or fat component with a medium droplet size • · · · · · ·

- 4 • · · · · · · · · · · · · · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · less than 200 nm, based on 1 part by weight of the oil or fat component.

Oil or fat components are understood to mean all water-insoluble lipids, preferably those that do not hydrolyze even in a strongly basic environment. Suitable oil or fat components are, for example, paraffins (petroleum jelly), paraffin oils, squalene, fatty alcohols (e.g. cetyl and stearyl alcohol), 2-octyldodecanol, dialkyl ether, etc. Triglycerides and other ester oils are less suitable.

Particularly preferred oil components with regard to stability in strongly basic environments and for the production of finely divided emulsions are low molecular weight, liquid hydrocarbons with 8-36 carbon atoms, dialkyl ethers with 12-36 carbon atoms or mixtures of these components. Suitable low molecular weight hydrocarbons are in particular branched hydrocarbons or synthetic products such as 1,3-di-(2-ethylhexyl)-cyclohexane, which is known under the trade name Cetiol®S. Suitable dialkyl ethers are, for example, cetyl isopropyl ether, stearyl methyl ether or symmetrical dialkyl ether such as di-n-octyl ether, which is known under the trade name Cetiol®OE. The oil components are preferably present in amounts of 5-20% by weight.

Suitable hydrophilic emulsifiers include, for example, anionic, zwitterionic, ampholytic or cationic surfactants, preferably nonionic emulsifiers with an HLB value above 10. The HLB value is

- 5 here means the size that can be determined experimentally according to the emulsion comparison method, in a rough approximation it can be estimated from the relationship HLB = 0.2 (100-L), where L is the mass fraction of lipophilic groups, i.e. e.g. fatty alkyl or acyl groups in wt.% in emulsifier molecules. Nonionic emulsifiers are preferred, e.g. fatty alcohol polyglycol ethers, which are obtained by adding more than one part by weight of ethylene oxide to 1 part by weight of fatty alcohol with 12-22 carbon atoms. An example of these emulsifiers is e.g. the addition product of 10 mol of ethylene oxide (EO) to behenyl alcohol, which is known under the trade name Mergital®B10, or the addition product of 12 mol of ethylene oxide to technical cetyl/stearyl alcohol, which is known under the trade name Eumulgin®B1. Fatty alcohol polyglycol ethers with an HLB value in the range of 10 to 18 are particularly suitable.

The fineness of the emulsion separation according to the invention is achieved, for example, by the so-called PIT method, where non-ionic emulsifiers are used in the production of the emulsion and the emulsion is heated above the phase inversion temperature during production.

The method is described, for example, in DE 40 10 393 A1 for polar oil components. For hydrocarbons and dialkyl ethers, which are preferred for the emulsions according to the invention, the choice of the HLB value is less critical and can optionally be dispensed with when co-emulsifiers are used.

A particular advantage of the compositions according to the invention in carrying out the keratin reduction step in a permanent wave process is that the emulsifier content can be very low and an amount of less than 0.4 parts by weight per part by weight of the oil or fat components is sufficient to achieve the fineness of separation according to the invention.

Finely divided emulsions are usually obtained by the phase inversion method, the average particle size of which ranges from 50-200 nm, i.e. they are not yet pure microemulsions, the average size of which is • · ·· · 4 · 4

- 6 • 4 4 4 4 4 4 4 4 · 4 4 4

4 444 444

444 44 44 4444 44 444 droplets lie below 50 nm, and which should be free of particles above 100 nm in order to be fully transparent.

Typical PIT emulsions suitable according to the invention are opalescent and have a bluish appearance in incident light and a brownish appearance in transmitted light. In particularly favorable cases, clear or transparent microemulsions are formed.

Due to the high efficiency of the inventive keratin reducing agents, the pH value can be relatively low, i.e. in the range around neutral value up to pH = 9, without reducing the durability of the styling. As is evident from the examples, at practically the same pH value and the same concentration of reducing agent, the durability of the styling when using a finely divided emulsion is significantly higher than when using an aqueous solution.

The sensory properties of the styled hair, which are very unsatisfactory when using sulfite or bisulfite as a keratin reducing agent, are also significantly improved by using the finely divided emulsion according to the invention. The shine, volume, combability and straightness of the hair are significantly improved compared to an aqueous solution of the reducing agent. This applies in particular to the dry combability of the styled hair, which is a measure of the surface properties of the cuticle.

In addition to the emulsified oil or fat components, the emulsifier and the keratin reducing agent, the compositions according to the invention may contain other excipients which will improve either the utility and technical properties or the appearance and sensory properties of the compositions and thus of the styled hair.

- 7 • 99 ·· 99 ·· • · · · · ···· · • · · · · · · · · · · · · · * 9 9 9 9 • 9 9 9 9 9 9

9 9 9 99 9999 99

For example, the effectiveness of keratin-reducing substances can be enhanced by keratinolytic, swelling-forming substances that allow the reducing substances to penetrate the hair structure more quickly and deeply. Such substances include urea, guanidine, imidazole, organic amines, e.g. alkanolamines or arginine, glycol ether, glycerol and lower alcohols with 1-4 carbon atoms. Urea, imidazole or monoethanolamine are preferably used. In the presence of an alkalizing agent such as alkali hydroxide, ammonia or ammonium carbonate, the effect of the swelling-forming components is further enhanced.

The viscosity of the composition according to the invention is adjusted to perform the keratin reduction step so that the composition can be easily applied to mechanically shaped hair, e.g. fixed on curlers or curlers, and can enter the hair, but at the same time does not drip or run off onto the scalp. Preferably, the viscosity is set in the range of 1000 to 10,000 mPa.s (25°C, D = 10/s).

Without special thickening, low-viscosity emulsions with a viscosity below 500 mPa.s (25°C, 10 D/s) are obtained when producing emulsions by the phase inversion method. Therefore, the compositions according to the invention preferably contain a thickener for the external, aqueous phase. Suitable thickeners are all water-soluble natural and synthetic polymer hydrocolloids, but also inorganic thickeners, e.g. layered silicates (e.g. bentonite) or thickened silicic acids.

Suitable natural thickeners are, for example, agar-agar, guar gum, locust bean gum, thickened starch and pectins; synthetic hydrocolloids are, for example, water-soluble cellulose derivatives, e.g. carboxymethylcellulose or hydroxyethylcellulose, cross-linked polyacrylic acids, polyvinylpyrrolidones, polyvinyl alcohols, polyethylene oxides. Biopolymers such as xanthan gum or gellan gum are also particularly suitable.

• 9

- 8 99 9 * · 9 9 » 9 9 9 • 99 99 9 99

999 999 9999

9 9 9 9 9 9

999 99 99 9999 99 9

Particularly low-viscosity compositions are used as aerosol foam using a suitable propellant gas such as nitrous oxide (N ₂ O), dimethyl ether, butane or 1,1,1,2-tetrafluoroethane.

Fragrances or odor correcting substances are used to mask odors, with preference given to alkali-stable perfume oils without aldehyde and hydrolytically cleavable components.

Other excipients may include, for example, thickeners, dyes, buffers, complexing agents and other surfactants, the total amount of which should not exceed 0.4 parts by weight per part by weight of the oil component.

Finally, they may also contain additives to improve skin tolerance and the properties of hair cosmetics, such as amino acids, protein hydrolysates, cationic polymers, panthenol, viamin or plant extracts.

The method according to the invention uses in further steps, e.g. in oxidative fixation, known means customary for permanent hair styling.

Common components of an aqueous fixative solution are oxidizing agents such as hydrogen peroxide or sodium bromide, surfactants, stabilizers, fragrances, and acids such as citric or tartaric acid used to adjust the pH to between 3-5.

Before the reduction step of the method according to the invention, it is also possible to further treat the hair using a composition containing hair protective components, e.g. cationic polymers or leveling components such as e.g. glucose or sorbitol.

• 9 9 9 · 9 9 · • • 9 9 9 9 9 9 9 9 9 9 9 999 9 9 9 9 9 9 9 • 9 • • 9 9 9 9 9 «9 9 9 9999 99 9 9

In the same way, it is possible to treat the hair after fixation so that the swelling of the hair is reduced again and the hair becomes stronger and more elastic. Such hair treatment agents may contain, for example, salts of di- or trivalent metals, e.g. calcium or aluminum salts, preferably salts of hydroxycarboxylic acids such as e.g. lactic acid, citric acid or tartaric acid.

Since the aqueous compositions for carrying out the process according to the invention are used immediately one after the other on mechanically shaped and curled and curled hair, it is particularly advantageous if the compositions for carrying out the process according to the invention are packaged separately in quantities appropriate and suitable for single use and sold as a single package. In this way, it is possible to sufficiently enable the home non-professional use of the process according to the invention so that the user uses the keratin reduction and fixation compositions optimally in terms of quantity and concentration and in the correct sequence.

Another variant consists of including a separately packaged activator in the sales package, which is mixed with the curling agent (keratin reducing agent) before use, which leads to an increase in the temperature of the keratin reducing agent. In this way, the effect of the curling agent can be increased and thus the required exposure time on the hair can be shortened. A substance that generates heat with the components of the keratin reducing agent, e.g. by hydration or oxidation of part of the reducing agent, can serve as an activator. Such suitable activators are, e.g., hydrogen peroxide or its addition products, anhydrous zeolites or anhydrous salts with a positive soluble heat, e.g. magnesium sulfate. The user can prevent incorrect dosage and use by using the enclosed instructions for use.

The following examples are intended to further illustrate the subject matter of the invention:

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- 10 ·· ·· ·· ··

9 9 9 9 9 9 9 9

9 9 9 9 9 9

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9 9 9 9 9

9999 ·« ·

Examples of the invention

Means according to the invention have been made for performing a keratin reduction step for a permanent wave process.

Table 1

Example 1 2 In Cetiol®OE 5.7 5.7 - Cetiol®S 5.7 5.7 - Mergital®B10 3.0 3.0 Strucure®3001 (30%) 3.0 3.0 - HS-CH2-COONH4 (50% in water) 20.0 - - N32S2O5 - 6.9 6.9 Urea (50% by weight in water) - 30.6 30.6 NH4HCO3 7.05 - - Ammonia solution (25%) 1.68 6.3 3.1

• φ · φ · • ·

- 11 • · · · · φ φ ··· *· ·· ···· φφ

Turpinal®SL (60%) 0.50 Texapon®NSO (28%) - 2.7 2.7 Water to 100 to 100 ad100 pH value 8.3 7.3 6.5 Dry combability [mJ] - 196 625 Durability (%) 81 95 89

Method of producing product 1 and 2 according to the invention

A finely divided emulsion was produced according to the PIT method from oil components (Cetiol OE, Cetiol S) and emulsifier (Mergital B10) and 10 wt.

parts of water. After cooling to 40°C, a thickener was added. The remaining ingredients were combined into an aqueous solution and mixed with the emulsion.

Production of comparator product V

The ingredients were combined into an aqueous solution.

·· Φ· ΦΦ 9·

- 12 • · · · · · · φ • ··· · · * φ φ φ φ • · · · · Φ φ ·*· ·· ·Φ ΦΦΦ· φφ φ

The following commercial products were used:

Cetiol®OE

Cetiol®S

Mergital®B10 Ctructure®3001 Natrosol®250 HR Texapon®NSO

Turpinal®SL di-n-octyl ether

1,3-bis-(2-ethylhexyl)-cyclohexane behenyl alcohol poly-(10EO)-glycol ether acrylates/ceteth-20-isocyanate copolymer hydroxyethyl cellulose fatty alcohol (Ci2-i4)-poly(2EO)-glycol ether sulfate, Na 1-hydroxyethane-1,1-diphosphonic acid • ·

- 13 Utility and technical tests

1. Durability (curi retention)

Hair strands 27 cm long and weighing 0.6 g were fixed on a standard wavy template for zigzag waves and in this state treated with a permanent wave spray, rinsed, treated with a fixing solution io and rinsed again. The composition of examples 1 and 2 and also comparative products 1V and 2V were chosen as the permanent wave agent, the fixing solution was an aqueous solution of 3.5 wt.% potassium bromide, wt.% sodium salt of fatty alcohol polyglycol ether sulfate, wt.% coconut fatty acid diethanolamide, 0.15 wt.% tartaric acid, 0.3 wt.% perfume oil and 1 wt.% sodium chloride.

After drying, the hair strands were released from the wave template. The wave length of 6 amplitudes defines the wave value. The hair strands were then loaded with a weight of 50 g and hung vertically in a water-filled cylinder for 60 minutes. After release, the length of 6 amplitudes was measured again. Durability (curi retention) results from the relationship Cr (%) = 100 (l-bo) / (l-lo). Here, they mean:

I = length of 6 amplitudes in the stretched state

Iq = length after permanent wave treatment Igo = length after 60 minutes of loading.

2. Dry combability

Twenty strands of hair (each 15 cm long, 2 g heavy) were treated

- 14 ·· ·« ·· • · · · · · · · • · · ♦ · • · * · · · · • ·

with a permanent wave solution, rinsed, fixed, rinsed and dried without applying mechanical hair styling. Then the hair strands were stored (conditioned) at a relative humidity of 20% and a temperature of 30°C for 12 hours and then combed. At the same time, 10 combing teeth were set on a fully automatic apparatus and the combing effort was measured.

The combability value per [in mJ] is the mean work integral over all 20 test hair strands.

Claims (7)

Patent claims CLAIMS 1. A method of permanently shaping hair wherein the hair is treated before 5 and / or after mechanical shaping, rinsing and rinsing and fixing the keratin reducing agent, characterized in that a finely divided oil-in-water emulsion containing at least 1% by weight of a water-soluble keratin reducing agent and at least 1% by weight of water-soluble keratin reducing agent is used to reduce keratin. 1% by weight of the emulsified oil or fat component having an average droplet size of less than 200 nm and less than 0.4 parts by weight of the hydrophilic emulsifier based on 1 part by weight of the oil or fat component. 15 Dec Composition according to claim 1, characterized in that it comprises, as a water-soluble keratin reducing agent, 1 to 20% by weight of a keratin reducing substance selected from the group of mercapto compounds, t-phosphines and sulphites. 20 May A composition for performing a keratin reduction step in a permanent hair shaping process in the form of a finely divided oil-in-water emulsion containing at least 1% by weight of a water soluble keratin reducing agent and at least 1% by weight of an emulsified oil or fat component with medium droplet size smaller 25 to 200 nm and less than 0.4 parts by weight of the hydrophilic emulsifier based on 1 part by weight of the oil or fat component. Composition according to claim 3, characterized in that the emulsified oil or fat component comprises at least one of the following: - 16 · • «· · · · · 98 9 9 9 9 • 9 9 9 9 99 9999 9 9 9 9 99 9 9 9 9 9 9 9 9 One liquid hydrocarbon having a total of 8 to 36 carbon atoms or one dialkyl ether of a total of 12 to 36 carbon atoms or a mixture thereof in an amount of from 5 to 20% by weight. Composition according to either of Claims 3 and 4, characterized in that it comprises, as the keratin reducing agent, an alkali or ammonium salt of thioglycolic acid, thiolactic acid or sulfuric acid. Composition according to one of Claims 3 to 5, characterized in that it comprises sulphite as the keratin reducing agent and further a substance with a swelling action selected from urea, imidazole and monoethanolamine. The composition of any one of claims 3 to 6, further comprising a thickener for the external, aqueous phase.