WO2021164974A1

WO2021164974A1 - Shaving aid containing hydroxyalkyl celluloses

Info

Publication number: WO2021164974A1
Application number: PCT/EP2021/051235
Authority: WO
Inventors: Philipp Rübenhaus; Elke Kaiser; Benjamin TRILLER
Original assignee: Beiersdorf Ag
Priority date: 2020-02-18
Filing date: 2021-01-21
Publication date: 2021-08-26
Also published as: EP4106713A1; DE102020202019A1

Abstract

The invention relates to a new shaving aid that contains hydroxyalkyl celluloses.

Description

Shaving aid containing hydroxyalkyl celluloses

The present invention describes a novel shaving aid, in particular a shaving gel, which contains hydroxyalkyl celluloses.

In a narrower sense, the term shave is associated with shaving a man's beard hair. Here, the whiskers are cut off as directly as possible on the surface of the facial skin.

Whether and where a shave takes place is also subject to fashion trends and cultural idiosyncrasies. If it is trendy or desired, the whiskers or only part of the whiskers are removed. It may also be desirable to remove the hair on other parts of the body. This aspect is increasingly coming to the fore with young girls (teens) and (young) women. The desire to remove hair, for example on the legs and / or in the armpits, is widespread.

The hair removal, i.e. the shave can be done as a dry or wet shave. With a wet shave, the hair is softened before the hair is cut. To do this, the hair to be shaved must absorb water. However, this water absorption can only take place once the sebum layer has been removed from the hair. To achieve this, shaving aids are used. In addition, the shaving aids have a lubricating effect, which leads to the razor blade sliding and ensures that there is little or no skin irritation when shaving.

There are various forms of shaving aids for wet shaving, starting with shaving soaps, through shaving creams, shaving foams and shaving gels.

The classic shaving soaps, which only existed in the past, contain a mixture of sodium and potassium soaps, with potassium soaps predominating. The main component of these soaps is stearate.

Shaving creams, shaving foams and shaving gels differ from classic shaving soaps in that they have a higher water content and more potassium soaps.

Shaving aids can also contain fatty acids, oils / fats and / or optionally other lipids. Oils and fats essentially consist of triacylglycerols, which are of vegetable or animal origin. In addition, the oils and fats mentioned contain small amounts of unsaponifiable components and acyl lipids. The triacylglycerols can be saponified with soaping agents.

The saponifying agents in shaving aids also neutralize the fatty acids they contain.

A look at textbooks on cosmetics shows that the saponification agents sodium hydroxide and potassium hydroxide can be used to produce shaving aids; over time, triethanolamine was also used as a saponification agent. With the use of triethanolamine for this purpose, the use of NaOH and KOH took a back seat. This is also clear in the prior art, for example in the documents EP 1649848 A1 and EP 2822529 B1.

Triethanolamine is a colorless, viscous liquid that smells like fish and has a strongly alkaline reaction. Triethanolamine is a synthetic compound that is synthesized from non-natural starting materials, namely ethylene oxide and ammonia.

It was therefore an object of the present invention to provide shaving aids which can do without the use of triethanolamine. Another focus should be on the selection of natural or nature-based raw materials. Ideally, biodegradability according to OECD 301 or 302 should also be given.

Surprisingly, a shaving aid, in particular a shaving gel, containing at least one hydroxyalkyl cellulose, at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, at least one simultaneous saponification and neutralizing agent, was able to achieve the above objects.

The shaving aid according to the invention is a cosmetic preparation which is intended for use on human hair and on human skin. The preparation according to the invention is particularly suitable for shaving beard hair. At the same time, however, hair on other parts of the human body can also be conveniently removed with the aid of the shaving aid according to the invention. The shaving aid according to the invention, in particular a shaving gel, is an aqueous preparation; the water content is in the range from 60 to 85% by weight, preferably 70 to 80% by weight, based on the total weight of the shaving aid.

The term “natural” in connection with natural ingredients for cosmetics is specified in ISO 16128. According to this guideline, natural, cosmetic ingredients can be summarized as substances that are obtainable from plants, animals, minerals or microorganisms, including those substances that are obtained from the named sources through physical processes, fermentation processes (only those fermentation processes that also occur in nature and lead to products that are also created in nature) and other manufacturing methods are obtained without intended chemical modification. The microorganisms may only be those that have not been genetically modified.

For the purposes of the present invention, nature-based substances are compounds that are derived from natural starting materials or are produced on the basis of natural starting materials.

The term biodegradability describes the process of degradation of organic compounds by living things, especially saprobionts. In the ideal case, inorganic substances such as CO2, O2 and ammonia are produced; Compounds that are used again by plants and microorganisms to build up organic compounds.

Organic chemical compounds that are easily biodegradable are classified according to OECD 301, for cosmetic compositions mostly OECD 301 B. These substances can be broken down quickly and completely.

Organic chemical compounds that are classified according to OECD 302 are restricted, but basically biodegradable.

According to the invention, at least one hydroxyalkyl cellulose is contained in the shaving aid. Hydroxyalkyl celluloses have a thickening effect and can therefore be counted among the thickeners. Thickeners are macromolecules that have a largely linear, partly networked structure and have intermolecular interaction forces that enable secondary and main valence bonds between the individual molecules and thus the formation of a network-like structure. Some of them are water-soluble or water-swellable natural or synthetic polymers that form gels or viscous solutions in aqueous systems. They increase the viscosity of the water by either binding water molecules (hydration) or by absorbing and enveloping the water in their interwoven macromolecules, while at the same time restricting the mobility of the water. Such water-soluble and water-swellable polymers represent a large group of chemically very different natural and synthetic polymers, the common feature of which is their solubility or swellability in water or aqueous media. The prerequisite for this is that these polymers have a sufficient number of hydrophilic groups for water solubility or water swellability and are not excessively crosslinked. The hydrophilic groups can be nonionic, anionic or cationic in nature.

Of known hydrocolloids that can be used in cosmetics and also dermatology, only natural or nature-based polymers are examined and / or used in connection with this invention, namely:

. organic, natural compounds such as agar agar, carrageenan, tragacanth, gum arabic, alginates, pectins, polyoses, guar flour, carob tree gum, dextrins, gelatine, casein, xanthan gum, gellan gum, succinoglycan gum, scleroglucan,

. organic, modified natural substances, such as B. carboxymethyl cellulose and other cellulose ethers, hydroxyethyl and -propyl cellulose and the like are used.

Thickeners according to the invention are hydroxyalkyl celluloses, that is to say celluloses whose hydroxyl groups are derivatized. Hydroxyalkyl celluloses are characterized by the following structural formula

in which R can represent a hydrogen or a hydroxyalkyl group. The hydroxyalkyl celluloses can also be described as cellulose ethers, the hydroxyalkyl groups advantageously being 2-hydroxyethyl, 2-hydroxypropyl or 2-hydroxybutyl groups. The use of hydroxyethyl cellulose is particularly preferred in the shaving aid according to the invention. In the case of hydroxyethyl celluloses, the radicals R in the above formula represent hydrogen or 2-hydroxyethyl radicals. Hydroxyethyl cellulose can be obtained, for example, from SE Tylose under the trade name Tylose H 100070 NP2.

According to the manufacturer, hydroxyalkyl celluloses are either biodegradable or easily biodegradable.

The at least one hydroxyalkyl cellulose is present with a total weight of 0.1 to 1.5% by weight, preferably 0.3 to 1.3% by weight, based on the total weight of the shaving aid.

A comparison of hydroxyalkyl cellulose, using the example of hydroxyethyl cellulose, to other natural thickeners is shown in Tables 1a and 1b. In the first table (1a), various natural or nature-based thickeners were examined. On the basis of the results with regard to sufficient viscosity and sufficient lubricity, 6 different thickeners (shown in bold in Table 1a) were further investigated, specifically with regard to an increase in viscosity and stability. The results, shown in Table 1b, showed that hydroxypropyl methyl cellulose and hydroxyethyl cellulose are suitable for thickening at a pH of about 10. The further investigations were therefore carried out with hydroxyalkyl celluloses and in particular with hydroxyethyl cellulose.

According to the invention, the shaving aid contains at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms. The fatty acids can be fatty acids each with a certain number of carbon atoms or mixtures of fatty acids that can come from natural sources, such as coconut oil, palm oil, soybean oil or beef fat (tallow). According to the invention, the fatty acids are advantageously selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid and / or oleic acid. In a preferred embodiment, the group comprises lauric acid, myristic acid and / or stearic acid, more preferably the group consists of lauric acid, myristic acid and stearic acid. In a further preferred embodiment, the at least one fatty acid is selected from fatty acids having 6 to 22 carbon atoms, lauric acid.

In a further, equally advantageous embodiment, an unsaturated fatty acid is included. According to the invention, the fatty acids are advantageously selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid and / or oleic acid.

In another equally preferred embodiment, the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is a mixture of fatty acids, with myristic acid and a mixture containing palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid being included. It is particularly preferred if the mixture consists only of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid. It is also very particularly preferred if the mixture of fatty acids consists of myristic acid and a mixture consisting of palmitic acid, stearic acid, myristic acid, arachinic acid and oleic acid.

The mixture of fatty acids can contain 44 to 50% by weight of palmitic acid, 45 to 50% by weight of stearic acid, 2 to 3% by weight of myristic acid, 1 to 2% by weight of arachidic acid and 0.5 to 1% by weight. % Oleic acid, based on the total weight of the mixture. Such a mixture can be obtained from Omya, for example, under the trade name Omyacid 48-cosmed grade MB. The named raw material contains according to the manufacturer's instructions

48.5% by weight palmitic acid, 47% by weight stearic acid, 2.5% by weight myristic acid,

1.5% by weight of arachidic acid and 0.5% by weight of oleic acid, based on the total weight of the raw material.

According to the invention, it is particularly advantageous if myristic acid and the mixture containing palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid, in particular consisting of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid, are present in a certain weight ratio. A weight ratio of myristic acid and said mixture of 2: 1 to 6: 1, in particular 2.2: 1 to 5.5: 1, leads to extremely satisfactory shaving gels which have good to excellent stability. This is clear from the results, which are shown by way of example in Table 2a; a weight ratio of myristic acid to the mixture of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid of 1.5: 1 leads to shaving aids that are unstable, whereas a weight ratio of 2.3: 1 leads to stable shaving aids. In addition, the sliding properties of the shaving aids in this embodiment are so good that further lubricants can advantageously be dispensed with.

In a further, equally preferred embodiment, the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is a mixture of fatty acids, namely myristic acid and stearic acid. Table 2b shows that a mixture of myristic acid and stearic acid also leads to stable shaving aids. This is particularly the case when the weight ratio of myristic acid to stearic acid is also from 2: 1 to 6: 1, in particular from 2.1: 1 to 5.5: 1.

In yet another, equally preferred embodiment, the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is a mixture of fatty acids, namely myristic acid and a mixture of stearic acid and palmitic acid. It is particularly advantageous if the mixture of stearic acid and palmitic acid consists of 40 to 60% by weight of stearic acid and 60 to 40% by weight of palmitic acid, ideally 50% by weight of stearic acid and 50% by weight of palmitic acid, based on the total weight of the mixture. In this case too, it is preferred if the weight ratio of myristic acid to the mixture consisting of stearic acid and palmitic acid is in the range from 2: 1 to 6: 1, in particular from 2.2: 1 to 5.5: 1.

The shaving aid according to the invention, in particular shaving gel, advantageously contains 3 to 25% by weight, preferably 5 to 15% by weight, of the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, based on the total weight of the shaving aid.

The shaving aid according to the invention contains NaOH and / or KOH as simultaneous saponifying agent and neutralizing agent, preferably KOH as the sole saponifying agent and neutralizing agent.

According to the invention, the simultaneous saponification and neutralizing agent is advantageously contained in the shaving aid at a content of 0.5 to 15% by weight, preferably 1.0 to 10% by weight, based on the total weight of the shaving aid.

Saponification can be understood as the hydrolytic cleavage of esters with the help of alkalis. The result is alcohols (glycerine in the case of triacylglycerols) and the salts of the corresponding fatty acids. The saponification number is a key figure for characterizing fats and oils. This number is a measure of the free or bound fatty acids contained in a fat or oil. The number indicates how much KOH (in mg) is required to neutralize the free acids contained in 1 g of fat / oil and the bound fatty acids to release the ester bonds.

The degree of saponification is given in%. At a degree of saponification of 100%, the saponification and neutralizing agent releases all bound fatty acids and neutralizes all fatty acids in total. At degrees of saponification above 100%, more saponification and neutralizing agent is contained than is required for complete saponification and neutralization, so that this excess is more base and the pH increases. With a degree of saponification below 100%, not all fatty acids can be saponified and neutralized, so that these fatty acids / fats / oils are unsaponified; this can lead to excessively fatty preparations.

In order to be suitable as a shaving aid for wet shaving, the shaving aid must have an alkaline pH value, namely a pH value of 8 to 12, preferably 8.5 to 11. According to the invention, this pH value is determined with the aid of NaOH and / or KOH, in particular KOH. However, it is also conceivable to use other natural neutralizing agents customary in the cosmetic industry in order to set an alkaline pH.

The addition of potassium hydroxide (KOH) can be increased so that degrees of saponification of more than 100% are achieved. When using long-chain fatty acids and / or vegetable fats and oils, which are saponified and neutralized, the pH value sometimes increases so much that it has to be reduced again by adding acid. The use of at least one organic acid is advantageous for this. The addition takes place after the saponification reaction or the saponification step.

The organic acid is particularly advantageously to be selected from the group consisting of tartaric acid, lactic acid and / or citric acid, more particularly citric acid.

If the shaving aid according to the invention contains at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further especially citric acid, the total content of the at least one organic acid is in a range from 0.005 to 10 wt. -%, preferably 0.1 to 5.0% by weight, based on the total weight of the shaving aid. The experiment shown in Table 3a shows that citric acid, in addition to lowering the pH, increases the stability of the shaving aid; in addition, the viscosity of the shaving aid is also increased.

The present invention thus also relates to a shaving aid, in particular a shaving gel, containing at least one hydroxyalkyl cellulose, at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, at least one simultaneous saponifying and neutralizing agent and at least one organic acid, in particular selected from Group tartaric acid, lactic acid and / or citric acid, further particularly citric acid.

The present invention also relates to the use of at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid in a shaving aid according to the invention as an agent for improving stability and / or increasing viscosity.

In addition, it is advantageous if the at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid, is added to the composition when the composition is still hot, ie a temperature of 60 up to 80 ° C. This is illustrated by the results presented in Table 3b. The addition of at least one organic acid, using the example of citric acid, to a shaving aid that is still at a temperature of 60 to 80 ° C. increases the thermal stability of the shaving aid.

The present invention thus also relates to the use of at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid in a shaving aid according to the invention as a means to improve stability and / or to increase viscosity, where the addition The at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid, is added to the shaving aid while the shaving aid has a temperature of 60 to 80.degree.

In many cases a lubricant is included in shaving aids. The lubricant is used to make the razor glide more easily over the skin to be shaved when shaving wet. Lubricant polymers are often used as lubricants; these are in particular long-chain polyethylene glycols with a very high molecular weight, for example PEG-90M. The lubricants are often synthetic compounds. The aim of the present invention was to identify and use natural ingredients that correspond to those synthetic substances in their function.

Surprisingly, it has been shown that certain vegetable oils act as lubricants. The addition of avocado oil and / or coconut oil has proven to be particularly effective. Since it is advantageous if avocado oil and / or coconut oil are not saponified or only to a small extent saponified, so that the oils mentioned can develop their effectiveness. The incorporation of both oils, individually or together, into the shaving aid according to the invention help the blade to glide more comfortably and more easily over the skin during a wet shave and not interfere with the cutting of the hair. Coconut oil also helps to positively influence the foam volume.

In addition, coconut oil helps to improve the stability of the shaving aid. This is clear from the results shown in Table 4.

If avocado oil and / or coconut oil are added to the shaving aid according to the invention, the total amount of avocado oil and / or coconut oil is 1 to 10% by weight, preferably 2 to 8% by weight, based on the total weight of the shaving aid .

The present invention thus also relates to a shaving aid, in particular a shaving gel, containing at least one hydroxyalkyl cellulose, at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, at least one simultaneous saponifying and neutralizing agent and optionally at least one organic acid, in particular selected from from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid, avocado oil and / or coconut oil.

The present invention also relates to the use of avocado oil and / or coconut oil in a shaving aid according to the invention as a lubricant. The present invention also relates to the use of avocado oil and / or coconut oil in a shaving aid according to the invention as an agent for improving stability.

In addition, the shaving aid according to the invention can contain further lubricants. These further lubricant may be selected from the group consisting of lanolin, especially purcellin oil, and Neocerit® Eucerit ^® ^®, in particular Eucerit ^®, are selected.

Other lubricants can be selected from the group of fatty alcohols with 6 to 22 carbon atoms. Fatty alcohols are linear, saturated or unsaturated primary alcohols (alkan-1-ols) with 6-22 carbon atoms. The fatty alcohols can advantageously be selected from the group consisting of cetyl alcohol and / or stearyl alcohol.

If the shaving aid according to the invention contains at least one further lubricant, the at least one further lubricant has a total weight of 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the total weight of the shaving aid , before.

Furthermore, the use of at least one alkyl palmitate, preferably cetyl palmitate, has proven to be advantageous for the shaving aid according to the invention. As can be seen from Table 5a, alkyl palmitates, in particular cetyl palmitate, can make a contribution to increasing the stability. This effect occurs in particular when at least one hydroxyalkyl cellulose, in particular a hydroxyethyl cellulose, is used as the thickener and the above-mentioned fatty acids, in particular those which are described in the preferred embodiments, are used.

The incorporation of at least one alkyl palmitate, in particular cetyl palmitate, has an emulsifying effect and therefore also leads to an improvement in the consistency of the shaving agent according to the invention. In addition, an improvement in the sliding of the shaver is observed when at least one alkyl palmitate is incorporated into the shaving aid according to the invention.

The results, which are shown in Tables 5a and 5b, show that the at least one alkyl palmitate, using the example of cetyl palmitate, contributes to increasing the stability of the shaving aid according to the invention, especially when a combination of hydroxyethyl cellulose and cetyl palmitate is used. If at least one alkyl palmitate, in particular cetyl palmitate, is contained in the shaving aid according to the invention, the at least one alkyl palmitate with a total content of 0.5 to 6.0% by weight, preferably 1.0 to 5.0% by weight, is %, based on the total weight of the shaving aid.

The present invention therefore also relates to a shaving aid, in particular a shaving gel, containing at least one hydroxyalkyl cellulose, at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, at least one simultaneous saponification and neutralizing agent, at least one alkyl palmitate, in particular cetyl palmitate, optionally at least an organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid and optionally avocado oil and / or coconut oil.

The present invention also relates to the use of at least one alkyl palmitate, in particular cetyl palmitate, in a shaving aid according to the invention as an agent for increasing stability.

According to the invention, the shaving aid can contain at least one humectant. Humectants can, for example, give the skin moisture and support the razor's ability to slide on the application area. The humectants are hygroscopic substances that can bind water. This water-binding capacity is based on hydrophilic groups such as hydroxyl groups, but also amine groups and carboxyl groups. Humectants are, for example, glycerin, butylene glycol, propylene glycol, Biosaccaride Gum-1, ethylhexyloxyglycerin, pyrrolidonecarboxylic acid, urea, sorbitol, xylitol, aloe vera gel and others. The use of propylene glycol and / or glycerine is preferred according to the invention.

The shaving aid according to the invention contains the at least one humectant with a total content of 0.01 to 30% by weight, preferably 5 to 20% by weight, based on the total weight of the shaving aid. According to the invention, further triacylglycerols, preferably of vegetable or animal origin, can be contained in the shaving aid. These other triacylglycerols are not coconut oil and / or avocado oil. The triacylglycerols are esters of glycerol with three fatty acids, which preferably have 6 to 22 carbon atoms. The triacylglycerols are usually oils or fats obtained from plants or animals. The vegetable oil (s) can preferably be selected from olive oil, jojoba oil and sunflower oil; the vegetable fat can for example be selected from palm fat.

If at least one further triacylglycerin, which is not coconut oil and / or avocado oil, is contained in the shaving aid according to the invention, then the at least one triacylglycerin with a total weight of 0.1 to 10% by weight, preferably 1 to 5% by weight, is %, based on the total weight of the shaving aid.

According to the invention, the shaving aid, in particular in the form of a shaving gel, can contain at least one further O / W emulsifier which is not an alkyl palmitate. O / W emulsifiers are characterized by HLB values that are greater than or equal to 8. HLB values can be determined using the following formula:

HLB = 20 x (1- Mii _pophii / M), where M _{üpophii stands} for the molar mass of the lipophilic component in the emulsifier and M for the molar mass of the entire emulsifier.

The following emulsifiers can act as O / W emulsifiers:

Ceteareth-25, sodium cetyl stearyl sulfate, laureth-4 phosphate, stearic acid, PEG-6 caprylic acid / capric acid glycerides, ceteth-2, ceteth-20, polysorbate 60, glyceryl stearate mixed with PEG-100 stearate, laureth-4, ceteareth-3, Laureth-23, steareth-2, glyceryl stearate mixed with PEG-30 stearate, polyglyceryl-2-PEG-4-stearate, ceteareth-20, methylglucose sesquistearate, steareth-10, PEG-20 stearate, steareth-21, Steareth-20, isosteareth-20, PEG-45 / dodecylglycol-copolymer, PEG-20-glyceryl stearate, polyglyceryl-2-laurate, isostearyl diglyceryl succinate, glyceryl stearate SE, PEG-20-methylglucose sesquistearate, glycerate-phosphate-4, tricetyl-cetosphate-stearate, glyceryl-phosphate-4-stearate , Trilaureth-4-phosphate, potassium cetyl phosphate, isosteareth-10, polyglyceryl-2-sesquiisostearate, ceteth-10, ceteareth-12, cetylstearyl alcohol in a mixture with PEG-20 stearate, PEG-30-stearate, PEG-40-stearate, PEG-100 stearate, polyglyceryl-3 distearate, polyglyceryl-10 stearate, Oleth-20, PEG-90 glyceryl isostearate and / or sodium st earoyl glutamate.

It is preferred according to the invention if the O / W emulsifiers are selected from the group glyceryl stearate citrate (INCI name: Glyceryl Stearate Citrate), polyglyceryl-3 Distearate, PEG-40 stearate, polyglyceryl-10 stearate (INCI name: Polyglyceryl-10 stearate), glyceryl stearate SE (INCI name: Glyceryl Stearate SE), sodium cetearyl sulfate (INCI name: Sodium Cetearyl Sulfate), stearic acid, Potassium cetyl phosphate (INCI name: Potassium Cetyl Sulfate), polyglyceryl-3 methylglucose distearate (INCI-Polyglyceryl Methylglycose Distearate) and / or sodium stearoyl glutamate (INCI name: Sodium Stearoyl Glutamate), particularly preferably from the group of potassium 3-methylglycetylphosphate, polyglyceryl-3-methylcetylphosphate, Oleth-20, PEG-90 glyceryl isostearate and / or sodium stearoyl glutamate.

Embodiments of the present invention which are advantageous according to the invention are characterized in that the shaving aid comprises the at least one further O / W emulsifier with a total weight of 0.01 to 5% by weight, preferably 0.1 to 2.5% by weight based on the total weight of the shaving aid.

The shaving aid according to the invention can contain preservatives. It should be noted that the preservatives must be suitable for use at high pH values, i.e. pH values greater than or equal to 8. The parabens, which are usually used in the cosmetic industry and phenoxyethanol, can advantageously be used. Preservatives do not need to be added at pH values greater than or equal to 10.

The shaving aid according to the invention can contain further cosmetic auxiliaries such as are customarily used in such a shaving aid.

According to the invention, the shaving aid according to the invention advantageously has a certain viscosity or consistency; the viscosity is measured with a Rheomat proRheo 123 brand viscometer (spindle 1, 25 ° C., 62.5 rpm).

In a changing temperature cabinet, temperature cycles are run through in continuous repetition. The temperature is kept at -10 ° C for 10 hours, then heated to + 40 ° C during 2 hours, kept at + 40 ° C for 10 hours and cooled to -10 ° C for 2 hours; this cycle repeats itself over and over again.

Production of a shaving gel according to the invention:

The shaving gel according to the invention can be produced by any known method which is suitable for producing shaving gels. However, it is advantageous according to the invention if the shaving gel according to the invention is produced in the following way: Put water in a suitable container.

Suspending the thickener (s) in a suitable medium (polymer phase). Adding the polymer phase to the water while stirring with a dissolver stirrer *; Stir until the thickener (s) has / are swollen.

Warm the resulting mixture in a water bath with stirring to about 80 ° C. Addition of the fatty acid (s); optional addition of at least one alkyl palmitate and possibly further emulsifiers.

Addition of the saponification agent (s) as soon as the fatty acids have melted and the batch is still at a temperature of 80 ° C.

Stir the batch for about 30 minutes in a water bath at 80 ° C.

Optional addition of the organic acid.

Remove from the water bath and allow to cool while stirring.

Addition of further optional raw materials with the exception of those raw materials that are only added at around 25 ° C.

Optional addition of preservative (s) at approx. 25 ° C. Addition of perfume oils at approx. 25 ° C.

Filling the batch into suitable vessels.

* The dissolver stirrer can be, for example, a dissolver stirrer from IKA. The stirrer should have a speed of 50 to 2000 rpm, advantageously a stirrer should be selected for the manufacture of a shaving gel according to the invention, which can move the stirrer at 200 to 1200 rpm.

Examples:

Table 1a:

* 0.5% by weight of each thickener was dissolved in water or incorporated hot and then rated.

Table 1b:

* 0.5% by weight of each thickener was dissolved in hot water at a pH of 10

Assessed viscosity increase and examined the stability for 7 days at room temperature.

Table 1c:

* too thin.

Table 2a:

* Mixture of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid. ** The stability was investigated immediately after production.

Table 2b:

Table 3a:

Table 3b:

Table 4:

Table 5a:

Table 5b:

* The stability was investigated immediately after production.

Table 6:

Further sample recipes:

The amounts are given in% by weight and relate to active contents, but not otherwise stated.

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Claims

1. Shaving aid, in particular a shaving gel, containing at least one hydroxyalkyl cellulose, at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, at least one simultaneous saponification and neutralizing agent.

2. Shaving aid according to claim 1, characterized in that the water content is in the range from 60 to 85% by weight, preferably 70 to 80% by weight, based on the total weight of the shaving aid.

3. Shaving aid according to claim 1 and / or 2, characterized in that the at least one hydroxyalkyl cellulose has hydroxyalkyl groups selected from 2-hydroxyethyl, 2-hydroxypropyl and / or 2-hydroxybutyl groups, in particular that the at least one hydroxyalkyl cellulose is a hydroxyethyl cellulose.

4. Shaving aid according to at least one of the preceding claims, characterized in that the at least one hydroxyalkyl cellulose is present with a total content of 0.1 to 1.5% by weight, preferably 0.3 to 1.3% by weight , based on the total weight of the shaving aid.

5. Shaving aid according to at least one of the preceding claims, characterized in that the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid and / or oleic acid, in particular from Lauric acid, myristic acid, and / or stearic acid.

6. Shaving aid according to at least one of claims 1 to 4, characterized in that the at least one fatty acid, selected from fatty acids with 6 to 22 carbon atoms, comprises at least one unsaturated fatty acid, in particular selected from the group lauric acid, myristic acid, palmitic acid, Stearic acid, arachidic acid and / or oleic acid.

7. Shaving aid according to claim 6, characterized in that the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is a mixture of fatty acids, with myristic acid and a mixture containing palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid, in particular with myristic acid and a mixture consisting of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid being included, further in particular where the we At least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, only one being the mixture of myristic acid and a mixture consisting of palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid.

8. Shaving aid according to claim 7, characterized in that the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms, a mixture of myristic acid and a mixture containing palmitic acid, stearic acid, myristic acid, arachidic acid and oleic acid, in particular consisting of palmitic acid, stea ric acid, myristic acid, arachidic acid and oleic acid, the weight ratio of myristic acid and said mixture being from 2: 1 to 6: 1, in particular from 2.2: 1 to 5.5: 1.

9. Shaving aid according to at least one of claims 1 to 4, characterized in that the at least one fatty acid selected from fatty acids with 6 to 22 carbon atoms is a mixture of fatty acids consisting of myristic acid and a mixture consisting of stearic acid and palmitic acid.

10. Shaving aid according to claim 9, characterized in that 40 to 60% by weight of stearic acid and 60 to 40% by weight of palmitic acid, preferably 50% by weight and stearic acid, are present in the mixture consisting of stearic acid and palmitic acid

50% by weight of palmitic acid, based on the total weight of the mixture.

11. Shaving aid according to claim 9 and / or 10, characterized in that the weight ratio of myristic acid to the mixture consisting of stearic acid and palmitic acid in the range from 2: 1 to 6: 1, in particular from 2.2: 1 to 5.5 : 1 lies.

12. Shaving aid according to at least one of claims 1 to 4, characterized in that the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is lauric acid.

13. Shaving aid according to at least one of claims 1 to 4, characterized in that the at least one fatty acid selected from fatty acids with 6 to 22, My ristic acid and stearic acid.

14. Shaving aid according to claim 13, characterized in that the weight ratio of myristic acid and stearic acid is from 2: 1 to 6: 1, in particular from 2.1: 1 to 5.5: 1.

15. Shaving aid according to at least one of the preceding claims, characterized in that the at least one fatty acid selected from fatty acids having 6 to 22 carbon atoms is present with a total content of 3 to 25% by weight, preferably 5 to 15% by weight based on the total weight of the shaving aid.

16. Shaving aid according to at least one of the preceding claims, characterized in that the simultaneous saponification agent and neutralizing agent is NaOH and / or KOH, preferably KOH.

17. Shaving aid according to at least one of the preceding claims, characterized in that the simultaneous saponification and neutralizing agent is contained with a total content of 0.5 to 15% by weight, preferably 1.0 to 10% by weight, be related on the total weight of the shaving aid.

18. Shaving aid according to at least one of the preceding claims, characterized in that the pH is in the range from 8 to 12, preferably from 8.5 to 11.

19. Shaving aid according to at least one of the preceding claims, characterized in that it also contains at least one organic acid, preferably selected from the group consisting of tartaric acid, lactic acid and / or citric acid, particularly preferably citric acid.

20. Shaving aid according to at least one of the preceding claims, characterized in that the at least one organic acid is present with a total content of 0.005 to 10.0% by weight, preferably 0.1 to 5.0% by weight, based on the total weight of the shaving aid.

21. Shaving aid according to at least one of the preceding claims, characterized in that it also contains avocado oil and / or coconut oil.

22. Shaving aid according to at least one of the preceding claims, characterized in that avocado oil and / or coconut oil are present with a total content of 1 to 10% by weight, preferably from 2 to 8% by weight, based on the total weight of the shaving aid.

23. Shaving aid according to at least one of the preceding claims, characterized in that at least one alkyl palmitate, preferably cetyl palmitate, is contained.

24. Shaving aid according to at least one of the preceding claims, characterized in that the at least one alkyl palmitate is present with a total content of 0.5 to 6.0% by weight, preferably 1.0 to 5.0% by weight on the total weight of the shaving aid.

25. Shaving aid according to at least one of the preceding claims, characterized in that it also contains at least one humectant, preferably selected from glycerin, butylene glycol, propylene glycol, Biosaccaride Gum-1, ethylhexyloxyglycerin, pyrrolidonecarboxylic acid, urea, sorbitol, xylitol, and / or aloe vera gel, especially propylene glycol and / or glycerine.

26. Shaving aid according to at least one of the preceding claims, characterized in that the at least one humectant is contained with a total weight of 0.01 to 30% by weight, preferably 5 to 20% by weight, based on the total weight of the shaving aid .

27. Use of at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid as an agent for improving stability and / or for increasing viscosity in a shaving aid according to at least one of the preceding claims.

28. Use according to claim 26, wherein the addition of the at least one organic acid, in particular selected from the group of tartaric acid, lactic acid and / or citric acid, further in particular citric acid, to the shaving aid takes place, while the shaving aid has a temperature of 60 to 80 ° C.

29. Use of avocado oil and / or coconut oil as a lubricant in a shaving aid according to at least one of claims 1 to 25.

30. Use of at least one alkyl palmitate, in particular cetyl palmitate, as a means of increasing stability in a shaving aid according to at least one of claims 1 to 25.