Patent Application
20230372214
This application claims priority to European Application No. 22174050.9, filed on May 18, 2022, the content of which is hereby incorporated by reference in its entirety.
The invention provides polyglycerol partial esters based on mono- and dicarboxylic acids, the production and use thereof, in cosmetics in particular.
Commercially available cosmetic film formers for sun protection and make-up formulations are mostly high-molecular-weight synthetic/petrochemically based, non-biodegradable polymers such as polyurethanes, polyacrylates, polyolefins, polyvinylpyrrolidones or the corresponding copolymers thereof. Examples thereof are products with the Antaron/Ganex (Ashland), Baycusan (Covestro) or Tego SP (Evonik) trade names.
Reasonably hydrophilic and thus reasonably readily water-soluble/water-swellable film formers based on natural polymers have likewise been described and are based for example on polysaccharides such as starch, cellulose and derivatives thereof or polypeptides. However, these do not exhibit good water resistance and often also show inadequate sun protection factor (SPF) boosting properties in sun protection or make-up formulations.
Products based on renewable raw materials are of ever-increasing interest to consumers not just from an environmental perspective, but from a toxicological perspective too. For instance, partial esters of polyols with fatty acids have already made inroads into diverse fields of use in cosmetics and other areas. Corresponding products having film “forming properties” are already on the market. Examples of these include:
However, all these products have inadequate film-forming properties compared to the abovementioned synthetic/petrochemically based polymers.
Partial esters of polyglycerols are a particularly interesting group of products on account of the diverse possibilities for variation:
EP0835862 describes polyglycerol partial esters of saturated or unsaturated, linear or branched fatty acids and polyfunctional carboxylic acids, obtainable by esterification of a polyglycerol mixture with saturated or unsaturated, linear or branched fatty acids having 12 to 22 carbon atoms and polyfunctional carboxylic acids having 4 to 54 carbon atoms and an average functionality of 2 to 2.4, the degree of esterification of the polyglycerol mixture being between 30 and 75%, and the use thereof as W/O emulsifiers and dispersion aids.
A disadvantage of the specific polyglycerol partial esters disclosed in the prior art is that they are liquid at room temperature, albeit highly viscous, and are thus unsuitable as film formers at body temperature.
EP1500427 describes polyglycerol partial esters of polyhydroxystearic acid and polyfunctional carboxylic acids, obtainable by esterification of a polyglycerol mixture with polyhydroxystearic acid and dimer fatty acid and/or di- and/or tricarboxylic acids and fatty acids having 6 to 22 carbon atoms. The polyglycerol partial esters are used for low-viscosity W/O emulsions and as dispersion aids.
A disadvantage of the method described in the prior art is that the products obtained are always highly viscous, i.e. but liquid at room temperature, even the product obtained at the end of the first step when the polyhydroxystearic acid is not added until the second step. Such products are unsuitable as film formers at body temperature.
EP1683781 describes polyglycerol partial esters of polyricinoleic acid and polyfunctional carboxylic acids, obtainable by esterification a) of a polyglycerol mixture with b) at least one particular polyricinoleic acid and optionally b1) polyhydroxystearic acid and c) at least one di- and/or tricarboxylic acid and d) at least one fatty acid according to methods known per se. The polyglycerol preferably has an average degree of condensation n of 1 to 11, preferably 2 to 6. A disadvantage of the method described in the prior art is that the products obtained are always highly viscous, i.e. but liquid at room temperature, even the product obtained at the end of the first step when the polyhydroxystearic acid is not added until the second step. Such products are unsuitable as film formers at body temperature.
EP3500550 describes polyglycerol partial esters obtainable by esterification of a polyglycerol with a carboxylic acid mixture comprising at least one polyhydroxycarboxylic acid of a hydroxycarboxylic acid having 8 to 32 carbon atoms, at least one short-chain dicarboxylic acid having 2 to 16 carbon atoms, at least one long-chain dicarboxylic acid having 24 to 44 carbon atoms and at least one linear or branched, saturated or unsaturated fatty acid having 14 to 24 carbon atoms. These are used as W/O emulsifiers.
Reactions of monocarboxylic acid (oleic acid or isostearic acid) with polyglycerol and sebacic acid or dimer acid (examples Ba, 12 and 13) with a degree of esterification of 38.7-48.3% are described here. The products are liquids that are highly viscous at room temperature. Reactions of monocarboxylic acids (oleic acid, isostearic acid or palmitic/stearic acid) with polyglycerol and a combination or sebacic acid and dimer acid (examples 4, 6b and 14) with a degree of esterification of 48.7-61.6% are additionally described. With the exception of example 14, the products are highly viscous liquids at room temperature.
EP2593076 describes polyglycerol oligoesters obtainable by reacting polyglycerol having 3 to 20 glycerol units with a dicarboxylic acid or a cyclic anhydride of such a dicarboxylic acid having 4 to 22 carbon atoms and a monocarboxylic acid having 4 to 24 carbon atoms in a molar ratio of from 1.5:1.0:0.1 to 3.0:1.0:3.0. The products can be used as emulsifiers, solubilizing agents and/or thickeners.
The described examples have a degree of esterification or only 12.5-25.1%; according to the claims a degree of esterification or 68.6% is possible if using polyglycerol-3 in the ratio 1.5:1.0:3.0. The described examples have max. 2 equiv. of monocarboxylic acid (ex. E10) and always 2 equiv. of polyol (to 1 equiv. of dicarboxylic acid).
EP2363387 describes (poly)glycerol partial esters containing an average (numerical average) of 0.75 to 2.25 acid residues of one or more carboxylic acids having 10 to 24 carbon atoms and containing an average (numerical average) of 0.005 to 0.5 residues of a polyfunctional carboxylic acid. The use as O/W emulsifiers is described.
The reaction of polyglycerols having a degree of polymerization of 2.8-5.3 with fatty acids (C16, C18 and C22) and citric acid is described in the examples. The esters obtained have a degree of esterification of 27-43% of the hydroxyl groups of the polyglycerol used; no melting point data are given. The molar ratio of monocarboxylic acid to citric acid is 3.5-21.5.
EP1417955 describes a “humectant” consisting of (A) a glycerol/glycerol condensate ester with saturated linear fatty acids having 16-28 carbon atoms and a saturated aliphatic dicarboxylic acid having 16-28 carbon atoms, wherein at least half of the available hydroxyl groups of the glycerol/glycerol condensate remain free (unesterified), (B) a water-soluble diol and (C) a water-soluble tri- or polyol.
WO2015013951 describes a water-free cosmetic composition comprising (a) an ester of polyglycerol having an average degree of polymerization of 2-12, a linear saturated C16-28 fatty acid and an aliphatic saturated C16-28 dicarboxylic acid, (b) a polyol having at least 3 hydroxy groups and (c) a glyceryl ester surfactant.
All known products of the prior art exhibit only very minimal film-forming properties or none at all. They likewise exhibit little or no SPF-boosting properties. The water resistance, especially in sun protection formulations, is also inadequate.
Although synthetic polymers such as polyacrylates deliver significant effects, they are not based on natural raw materials and are also not biodegradable.
The skin feel of the known products of the prior art is unappealing, since corresponding cosmetic formulations that contain them are very tacky and/or are absorbed only slowly into the skin.
It was an object of the invention to provide a composition that is able to overcome at least one disadvantage of the products of the prior art.
It has surprisingly been found that the polyglycerol partial esters described hereinbelow achieve the object of the invention.
The present invention accordingly provides polyglycerol partial esters that are characterized by a particular choice of polyglycerol and by specific ratios of the different carboxylic acids that have undergone esterification.
The invention further provides a method for preparing the polyglycerol partial esters of the invention and for the use of the polyglycerol partial esters in cosmetic applications.
The invention also includes the following embodiments:
An advantage of the present invention is that the polyglycerol partial esters described herein may be prepared from exclusively renewable raw materials, unlike the polyacrylates described above. A further advantage is that the polyglycerol partial esters described herein can be prepared on the basis of principles of green chemistry.
Another advantage of the present invention is that formulations can be provided that are polyglycol ether-free.
A further advantage is that the polyglycerol partial esters described herein are biodegradable, unlike the polyacrylates described above.
A further advantage is that the polyglycerol partial esters described herein have a good ecotoxicological profile.
A further advantage of the polyglycerol partial esters described herein is that they are very mild on the skin, not irritating and non-toxic.
Another advantage of the polyglycerol partial esters described herein is that they have improved sensory properties in formulations. The tackiness of sun protection formulations is reduced after application. The formulations undergo rapid absorption into the skin, since absorption is increased during application and for 5 min thereafter on the skin.
Another advantage of the polyglycerol partial esters described herein is that they give rise to enhancement of “velvety-silkiness” in formulations.
A further advantage is that the polyglycerol partial esters described herein have a good skin-moisturizing effect.
Another advantage is that the polyglycerol partial esters described herein impart an increased sun protection factor to the sun protection formulations.
Another advantage is that the polyglycerol partial esters described herein are very well suited to be used in sun protection formulations having very high concentrations of UV light protection filters. A further advantage of the polyglycerol partial esters described herein is that they impart very high water resistance to the formulations. In sun protection formulations this results in the formulations ensuring prolonged UV protection in the water or after bathing.
Another advantage of the polyglycerol partial esters according to the invention is that they impart increased wear resistance to the colour pigments when used in make-up applications.
In the context of pigment-containing formulations, a further advantage of the polyglycerol partial esters according to the invention is that they permit good dispersion of pigments in the formulations.
A further advantage of the polyglycerol partial esters described herein is that they have good compatibility with formulations containing UV protection filters or pigments.
In general, the polyglycerol partial esters described herein impart good stability to the formulations. Another advantage of the polyglycerol partial esters according to the invention is that they are easily processable, since they mix readily with typical cosmetic oils and can be rapidly incorporated into corresponding emulsions.
A further advantage of the polyglycerol partial esters described herein is that they impart high gloss to solid or waxy formulations such as lipsticks.
Yet another advantage of the polyglycerol partial esters according to the invention is that they are particularly tolerant to electrolytes, which means that, for example, formulations containing large amounts of salt remain stable.
A further advantage of the polyglycerol partial esters according to the invention is that they have a structuring and viscosity-increasing effect in formulations having high oil contents or even pure oils.
The present invention thus provides a polyglycerol partial ester obtainable by esterification
The polyglycerol partial esters according to the invention are mixtures of different substances; it is therefore clear to those skilled in the art that the numerical values specified are average values across the mixture.
The term “polyglycerol” is for the purpose of the present invention to be understood as meaning a polyglycerol that may also contain glycerol. Consequently, for the purposes of calculating amounts, masses and the like, any glycerol fraction should also be taken into consideration.
Because of its polymeric character, the polyglycerol is a statistical mixture of various compounds. Polyglycerol may have ether bonds formed between two primary, one primary and one secondary, and two secondary positions of the glycerol monomers. For this reason, the polyglycerol base framework does not usually consist exclusively of linearly linked glycerol units, but may also comprise branchings and rings. For details see for example “Original synthesis of linear, branched and cyclic oligoglycerol standards”, Cassel et al., J. Org. Chem. 2001, 875-898.
The same applies to the term “polyglycerol partial ester” in the context of the present invention.
The term “short-chain dicarboxylic acid” is in the context of the present invention to be understood as meaning dicarboxylic acids having 4 to 18, preferably 4 to 14, more preferably 6 to 10, carbon atoms.
The term “long-chain dicarboxylic acid” is in the context of the present invention to be understood as meaning dicarboxylic acids having 24 to 44, preferably 30 to 40, more preferably 34 to 38, carbon atoms.
The term “long-chain monocarboxylic acid” is in the context of the present invention to be understood as meaning monocarboxylic acids having 18 to 32, preferably 18 to 26, more preferably 20 to 22, carbon atoms.
The polyglycerol partial ester obtainable by esterification of carboxylic acids according to the invention can of course also be obtained by esterification of the corresponding carboxylic acid derivatives, for example the anhydrides or carboxylic esters thereof (such as methyl or ethyl esters). If the polyglycerol partial esters are obtained by (trans)esterification of a polyol ester of the di- and/or monocarboxylic acids, it will be apparent to those skilled in the art that the molar ratio of polyglycerol a) to the sum total of dicarboxylic acid components b1) and b2) to carboxylic acid component c) relates not to the number of molecules of the respective polyol ester, but to the number of acyl residues of the di- and/or monocarboxylic acid provided by the respective polyol ester.
For the present invention, it is important that the polyglycerol used has an average degree of condensation N of 2.4 to 15.0, preferably 2.6 to 10.0, especially 2.8 to 6.0.
The average degree of condensation of the polyglycerol N is calculated via its hydroxyl value (OHV, in mg KOH/g) according to the following formula:
Suitable detection methods for determining the hydroxyl value are in particular those according to DGF C-V 17 a (53), Ph. Eur. 2.5.3 Method A and DIN 53240.
Unless otherwise stated, all stated percentages (%) are percentages by weight.
Polyglycerol partial esters preferred in accordance with the invention are characterized in that the polyglycerol used has a glycerol content of 0.05% by weight to 25.0% by weight, preferably of 0.1% by weight to 15.0% by weight, more preferably of 0.1% by weight to 10.0% by weight, where the percentages by weight are based on the total amount of polyglycerol used. The stated percentages by weight are determined here by the GC method described hereinbelow.
Polyglycerol partial esters preferred in accordance with the invention are characterized in that the polyglycerol used has a diglycerol content of 0.1% by weight to 45.0% by weight, preferably of 0.5% by weight to 35.0% by weight, more preferably of 3.0% by weight to 30.0% by weight, where the percentages by weight are based on the total amount of polyglycerol used.
The stated percentages by weight are determined here by the GC method described hereinbelow.
It is advantageous when the polyglycerol used has a polydispersity index of more than 0.8, preferably of more than 1.0, more preferably of more than 1.2.
For the purposes of the present invention, the polydispersity index is calculated as
where ni is the degree of condensation of the individual oligomer i, N the average degree of condensation of the polyglycerol [already described above and how to determine] and xi the proportion of the oligomer i in the polyglycerol mixture, as determined in the GC method described hereinbelow.
A suitable method for determining the oligomer distribution of the polyglycerol in a given polyglycerol partial ester comprises the hydrolysis or alcoholysis of the partial ester, separation of the resulting polyglycerol from the carboxylic acid compounds formed and analysis by gas chromatography after derivatization.
For this purpose, 0.6 g of polyglycerol ester is boiled under reflux in 25 ml of 0.5 N ethanolic KOH for 30 minutes and adjusted to pH 2-3 with sulfuric acid. The carboxylic acids are separated by extracting with three portions of petroleum ether of equivalent volume. The combined extracts are evaporated to a volume of approx. 10 ml. A 0.5 ml aliquot is transferred to an autosampler vial and, after addition of 0.5 ml of MTBE and 1 ml of TMPAH solution (trimethylanilinium hydroxide in methanol) as derivatization agent, analysed by GC.
The fatty acid analysis by GC is carried out using a gas chromatograph equipped with a split/splitless injector, a capillary column and a flame ionization detector.
When using these conditions, the methyl carboxylate esters are separated according to their chain length.
The relative content of the individual carboxylic acids (chain-length distribution) is evaluated as a percentage of the peak area.
The residue after extraction with petroleum ether is adjusted to pH 7-8 by addition of barium hydroxide solution. The precipitated barium sulfate is removed by centrifugation. The supernatant is drawn off and the residue extracted with three 20 ml portions of ethanol. The combined supernatants are evaporated at 80° C./50 mbar. The residue is dissolved in pyridine. 500 μl of the solution is transferred to an autosampler vial and 1 ml of MSTFA (N-methyl-N-trifluoroacetamide) added. The vial is closed and heated to 80° C. for 30 minutes.
The GC analysis of the polyglycerol component (as the trimethylsilyl derivative) is carried out using a gas-liquid chromatograph equipped with an on-column injector and an FID detector.
Conditions:
Under these conditions, the polyglycerols are separated according to their degree of condensation. In addition, cyclic isomers are separated from linear isomers up to a degree of condensation of four.
The peak areas of the individual oligomers are separated by a perpendicular line applied at the lowest point of the trough between peaks.
Since the resolution of oligomers higher than hexaglycerol is poor, the peaks of heptaglycerol and higher oligomers are combined as “heptaglycerol and higher” and treated as heptaglycerol for the purposes of calculating the polydispersity index. Linear and cyclic isomers are likewise combined in the calculation of the polydispersity index.
The relative ratio of the individual polyglycerol oligomers and isomers is calculated from the GC peak area obtained as described above.
The described GC analyses of the carboxylic acid and polyglycerol components can of course also be performed on the raw materials used for the preparation of the polyglycerol partial esters of the invention.
Polyglycerol partial esters preferred in accordance with the invention are characterized in that the polyglycerol used has a content of cyclic isomers of 1% by weight to 50% by weight, preferably of 2% by weight to 40% by weight, more preferably of 3% by weight to 30% by weight.
The stated percentages by weight are determined by the GC method described above and are based on the amount of the overall polyglycerol used.
It is preferable in accordance with the invention when the employed short-chain dicarboxylic acid in the polyglycerol partial ester of the invention is selected from aliphatic, linear dicarboxylic acids, especially succinic acid, maleic acid, tartaric acid, malic acid, fumaric acid, sorbic acid, α-ketoglutaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and brassylic acid, with particular preference given to adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
It is preferable in accordance with the invention when the employed long-chain dicarboxylic acid in the polyglycerol partial ester of the invention is selected from the group comprising dimer fatty acids that are oligomeric forms of various unsaturated monomeric fatty acids. Dimer fatty acids are a mixture of acyclic and cyclic dicarboxylic acids obtained by catalytic dimerization of unsaturated fatty acids having 12 to 22 carbon atoms. For the preparation and use of dimer acids and the physical and chemical properties thereof, reference is made to the publication “The Dimer Acids: The chemical and physical properties, reactions and applications”, ed. E. C. Leonard; Humko Sheffield Chemical, 1975, Memphis. Tenn.
The dicarboxylic acids may also contain tri- and polyfunctional carboxylic acids to a minor extent. The functionality of the mixture should not exceed, on molar average, a value of 2.4. Particularly suitable as the long-chain dicarboxylic acid for the end use in accordance with the invention is dimer acid or a mixture of dimer and trimer acid (for example Radiacid 0977 from Oleon) obtained from vegetable oils having a high content of unsaturated C18 fatty acids (oleic, linoleic, linolenic acid).
Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain, saturated and linear monocarboxylic acids used are selected from hydroxy-substituted and unsubstituted fatty acids.
When mixtures of hydroxy-substituted and unsubstituted fatty acids are in accordance with the invention used as long-chain, saturated and linear monocarboxylic acids, these fatty acid mixtures preferably have a content of hydroxy-substituted fatty acids within a range of from 0.1% by weight to 25% by weight, preferably from 1% by weight to 10% by weight, where the percentages by weight are based on all long-chain, saturated and linear monocarboxylic acids.
Polyglycerol partial esters particularly preferred in accordance with the invention are characterized in that the long-chain, saturated and linear monocarboxylic acids used are selected from unsubstituted fatty acids.
In this connection, the long-chain, saturated and linear monocarboxylic acids used are selected in particular from stearic acid, arachidic acid and behenic acid. Typical commercially available products are: technical-grade stearic acid containing at least 92% C18 (for example Mascid 1892 from Musim Mas, Palmac 90-18 from 101, Radiacid 0152 from Oleon, Wilfarin SA-1892 from Wilmar), technical-grade stearic acid containing at least 98% C18 (for example Edenor C18-98 MY from Emery, Palmac 98-18 from 101), technical-grade arachidic acid (for example Palmera A5020 from KLK, Nouracid RE07 from Oleon, Nouracid RD3030 from Oleon), technical-grade behenic acid containing at least 60% C22 (for example Palmera A6022 from KLK), technical-grade behenic acid containing at least 85% C22 (for example Palmera A8522 from KLK, Radiacid 0560 from Oleon) and technical-grade behenic acid containing at least 92% C22 (for example Palmera A9322 from KLK).
Polyglycerol partial esters preferred in accordance with the invention are characterized in that the total content of aromatic mono- and dicarboxylic acids based on all mono- and dicarboxylic acids used is from 0% by weight to 35% by weight, preferably from 0.1% by weight to 25% by weight. Polyglycerol partial esters particularly preferred in accordance with the invention are characterized in that the total content of aromatic mono- and dicarboxylic acids based on all mono- and dicarboxylic acids used is 0% by weight.
Polyglycerol partial esters alternatively particularly preferred are characterized in that the total content of aromatic mono- and dicarboxylic acids based on all mono- and dicarboxylic acids used is from 5% by weight to 35% by weight, preferably from 11% by weight to 25% by weight.
From the amounts of the various components used in the esterification, it is clearly evident that it is preferable in accordance with the invention when the polyglycerol partial ester of the invention has a degree of esterification of 35% to 100%, preferably of 50% to 98%, more preferably of 68% to 95%. The determination of the degree of esterification of the polyglycerol partial esters of the invention is described hereinbelow in the examples.
In this connection, it is particularly preferable that the polyglycerol partial ester of the invention has an acid value of less than 25, preferably less than 15, especially within a range from 0.1 to 10, more preferably within a range from 0.5 to 10.
For the present invention it is advantageous and thus preferable that the value for the hydrophilic-lipophilic balance (HLB value) of the polyglycerol partial ester is from 2.0 to 8.0, preferably from 2.5 to 7.5 and more preferably from 3 to 5.2. The HLB value is a measure or the degree of hydrophilicity or lipophilicity of the molecule determined through the calculation of values for the different regions of the molecule. For the purposes of the present invention, the HLB value of the polyglycerol partial esters is calculated as follows:
HLB=(mp/(mp+ma))*20,
where mp is the mass of the polyglycerol and ma the mass of the carboxylic acid mixture used in the synthesis of the polyglycerol ester (comprising mono- and dicarboxylic acids). For example, the esterification of 100 g of polyglycerol with 90 g of monocarboxylic acid and 10 g of dicarboxylic acid would result in an HLB value of (100 g/(90 g+10 g+100 g))*20=10, irrespective or the degree of polymerization of the polyglycerol and the nature or the carboxylic acids used.
Polyglycerol partial esters preferred in accordance with the invention are characterized in that they have an iodine value of less than 20, preferably less than 12, particularly preferably less than 5. A suitable method for determining the iodine value in the context of the present invention is EN 14111:2003.
It is preferable in accordance with the invention that the polyglycerol partial ester of the invention has a melting point of greater than 35° C., preferably greater than 40° C., in particular greater than 50° C., more preferably within a range from 51° C. to 100° C.
The polyglycerol partial esters of the present invention can be prepared by classical esterification methods; in place of the carboxylic acids it is of course also possible to use the corresponding carboxylic acid derivatives, for example the anhydrides or carboxylic esters thereof (such as methyl or ethyl esters). It is also possible to use triglycerides, especially in the form of natural fats and oils, so long as they provide the carboxylic acids required according to the invention.
Polyglycerol partial esters according to the invention are preferably obtained by the method described hereinbelow; the present invention thus further provides a method for preparing a polyglycerol partial ester, said method comprising the method steps of
In the method according to the invention, preference is given to using those polyglycerols, monocarboxylic acids and dicarboxylic acids that are cited above as used with preference for the polyglycerol partial ester according to the invention. Correspondingly graduated preferences can be applied by analogy.
In the method according to the invention, method step C) can be carried out as a one-pot reaction or else as a stepwise process.
If method step C) is carried out as a one-pot reaction, the carboxylic acid mixture is esterified with the polyglycerol.
If method step C) is carried out as a stepwise process, the monocarboxylic acid and the dicarboxylic acids are added sequentially and esterified with the polyglycerol; strictly speaking, the monocarboxylic acid and the dicarboxylic acids are not provided as a carboxylic acid mixture, but this process is equivalent. In this connection it is possible for the polyglycerol to first undergo reaction with the monocarboxylic acid before then undergoing crosslinking with the dicarboxylic acids in a second step. However, the reverse stepwise synthetic sequence comprising an initial reaction of the polyglycerol with the dicarboxylic acids and then a subsequent reaction with the monocarboxylic acid is possible too. Splitting the Individual reactants into several portions and multistage reactions is another possible application.
Since the polyglycerol partial esters according to the invention have an excellent use profile in cosmetic formulations, the present invention further provides a formulation, especially a cosmetic formulation, comprising 1) the polyglycerol partial ester according to the invention or a polyglycerol partial ester obtainable by the method according to the invention.
Preferably, the formulation according to the invention comprises a further component 2) at least one substance selected from the group comprising UV light protection filter substances and pigments, especially UV light protection filter substances, which are preferably organic.
The UV light protection filter substances present may for example be organic substances that are capable of absorbing ultraviolet rays and re-emitting the absorbed energy in the form of longer-wavelength radiation, for example heat.
UVB filters can be oil-soluble or water-soluble. Examples of oil-soluble UVB light protection filters include:
3-benzylidenecamphor derivatives, for example 3-(4-methylbenzylidene)camphor (INCI: 4-Methylbenzylidene Camphor), 4-aminobenzoic acid derivatives, for example 2-ethylhexyl 4-(dimethylamino)benzoate (INCI: Ethylhexyl Dimethyl PABA), 2-hydroxyethyl 4-{bis[2-(2-hydroxyethoxy)ethyl]amino}benzoate (INCI: PEG-25 PABA), cinnamic esters, for example 2-ethylhexyl 4-methoxycinnamate (INCI: Ethylhexyl Methoxycinnamate), isopentyl 4-methoxycinnamate (INCI: isoamyl p-Methoxycinnamate), 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (INCI: Octocrylene), salicylic esters, for example 2-ethylhexyl salicylate (INCI: Ethylhexyl Salicylate), homomenthyl salicylate (INCI: Menthyl Salicylate), 3,3,5-trimethylcyclohexyl salicylate (INCI: Homosalate), 2-hydroxybenzoic acid-2,2′,2″-nitrilotriethanol (1:1) (INCI: TEA-Salicylate), benzophenone derivatives, for example 2-hydroxy-4-methoxybenzophenone (INCI: Benzophenone-3), 22′-dihydroxy-4-methoxybenzophenone (INCI: Benzophenone-8), 2-hydroxy-4-methoxy-4′-methylbenzophenone (INCI: Benzophenone-10), triazine derivatives, for example tris(2-ethylhexyl) 4,4′,4″-(1,3,5-triazine-2,4,6-triyltriimino)tribenzoate (INCI: Ethylhexyl Triazone, obtainable for example under the trade name Uvinul T 150 from BASF), iscotrizinol (INCI: Diethylhexyl Butamido Triazone) and 2,4,6-tri(4-biphenylyl)-1,3,5-triazine (INCI: Tris-Biphenyl Triazine).
An additional UVB filter is the (3-(4-(2,2-bis(ethoxycarbonyl)vinyl)phenoxy)propenyl)methoxysioxane/dimethylsiloxane copolymer (INCI: Polysilicone-15) obtainable for example under the trade name Parsol SLX.
Useful water-soluble UVB sun protection filters include for example: salts of 2-phenylbenzimidazole-5-sulfonic acid, such as its alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium and glucammonium salts, and also the sulfonic acid itself having the INCI name Phenylbenzimidazole Sulfonic Acid, sulfonic acid derivatives of benzophenone, for example 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (INCI: Benzophenone-4) and salts thereof, benzenesulfonic acid derivatives of 3-benzylidenecamphor, for example 4-[(E)-(4,7,7-trimethyl-3-oxobicyclo[2.2.1]hept-2-ylidene)methyl]benzenesulfonic acid (INCI: Benzylidene Camphor Sulfonic Acid) and salts thereof.
Examples of typical oil-soluble UVA/broadband light protection filters that may be used include derivatives of benzoylmethane, for example 1-(4-methoxyphenyl)-3-[4-(2-methyl-2-propanyl)phenyl]-1,3-propanedione (INCI: Butyl Methoxydibenzoylmethane) or 1-(4-isopropylphenyl)-3-phenyl-1,3-propanedione (INCI: isopropyl Dibenzoylmethane), triazine derivatives, for example 2,2′-[6-(4-methoxyphenyl)-1,3,5-triazine-2,4-diyl]bis{5-[(2-ethylhexyl)oxy]phenol} (INCI: Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, obtainable for example under the trade name Tinosorb S from BASF), N,N′-bis[4-[5-(1,1-dimethylpropyl)-2-benzoxazolyl]phenyl]-N″-(2-ethylhexyl)-1,3,5-triazine-2,4,6-triamine (INCI: Ethylhexyl Bis-Isopentylbenzoxazolylphenyl Melamine, obtainable under the trade name Uvasorb K2A from 3V Sigma), and derivatives of benzophenone, for example hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate (INCI: Diethylamino Hydroxybenzoyl Hexyl Benzoate).
Useful water-soluble UVA/broadband light protection filters include, for example: 3,3′-(1,4-phenylenedimethylene)-bis(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-ylmethanesulfonlc acid) and salts thereof, especially the corresponding sodium, potassium or triethanolammonium salt, which is also described as benzene-1,4-di(2-oxo-3-bornylidenemethyl-10-sulfonic acid) and has the INCI name Terephthalylidene Dicamphor Sulfonic Acid (obtainable under the trade name Mexoryl SX), 2,2′-(1,4-phenylene)-bis(6-sulfo-1H-benzimidazole-4-sulfonic acid) and salts thereof, the corresponding sodium, potassium or triethanolammonium salts, for example disodium 2,2′-(1,4-phenylene)-bis(6-sulfo-1H-benzimidazole-4-sulfonate) having the INCI name Disodium Phenyl Dibenzimidazole Tetrasulfonate, trade name for example Neo Heliopan AP.
Examples of other UVA/broadband filters are 2,2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethyl-2-pentanyl)phenol] (INCI: Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, obtainable for example under the trade name Tinosorb M from BASF), 2-(2H-benzotriazol-2-yl)-4-methyl-6-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethyisiyl)oxy]disiloxany]propyl]phenol (INCI: Drometrizole Trisiloxane, trade name: Mexoryl XL), (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl 2-aminobenzoate (INCI: Menthyl Anthranilate) and 2-ethoxyethyl (2E)-3-(4-methoxyphenyl)acrylate (INCI: Cinoxate).
The UV filters may of course also be present in mixtures in the compositions according to the invention.
In addition to the soluble UV light protection filter substances mentioned, insoluble pigments may also be used for this purpose, namely finely dispersed metal oxides or salts, for example titanium dioxide, zinc oxide, iron oxide, aluminium oxide, cerium oxide, zirconium oxide, silicates (talc), barium sulfate and zinc stearate. The particles should here have an average diameter of less than 100 nm, for example of between 5 and 50 nm and especially between 15 and 30 nm. They may be spherical in shape, but it is also possible to use particles that are ellipsoidal in shape or have a shape that deviates in another way from spherical. Also possible however are micronized organic pigments, for example 2,2′-methylenebis[6-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethyl-2-pentanyl)phenol] (INCI: Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, obtainable for example under the trade name Tinosorb M from BASF), having a particle size of <200 nm, which is obtainable for example as a 50% aqueous dispersion.
In addition, further suitable UV light protection filters are given in the review by P. Finkel in SÖF W Journal, 122, 543 (1996) or in the chapter “The Chemistry of Ultraviolet Filters” by N. A. Shaath in “Principles and Practice of Photoprotection”, S. Q. Wang, H. W. Lim (eds.), Springer International Publishing, Switzerland, 2016.
It is preferable in accordance with the invention that component 2) of the formulation according to the invention is selected from at least two, preferably at least three, more preferably at least four, substances selected from the group of UV light protection filter substances.
It is preferable in accordance with the invention that component 2) of the formulation according to the invention is selected from the group comprising organic UV light protection filter substances, especially from the group of triazine derivatives.
It is in addition preferable in accordance with the invention that component 2) of the formulation according to the invention is selected from the group of UV light protection filter substances comprising, preferably consisting of,
It is in addition preferable in accordance with the invention that component 2) of the formulation according to the invention is selected from the group of pigments comprising unmodified or surface-modified, inorganic or organic pigments, preferably inorganic pigments such as activated carbon, talc, iron oxide pigments, titanium dioxide, zinc oxide, silica, cerium oxides, zirconium oxides, aluminium oxides, calcium carbonate, barium sulfate, chromium oxides, manganese oxides, bismuth oxychloride, ultramarine, calcium sulfate, alkali magnesium silicates or mixtures thereof.
Examples of organic pigments may be: carotenoids, chlorophylls, xanthophylls, caramel and the salts of the recited examples and also dyes obtained from fruits of plants or other plant parts, for example from orange, cacao, turmeric, shea, sandalwood, onion, carob tree fruit, paprika, maize, tomato, beetroot, peanut, grape, red cabbage, red rice, radish, elderberry, lingonberry, blueberry, raspberry, blackberry, boysenberry, gooseberry, cranberry, saffron, strawberry, cherry, tea, hibiscus, plum, blueberry or mulberry. Also employable as dye pigments are the substances approved and suitable for cosmetic purposes, as listed for example in the publication “Kosmetische Färbemittel” [Cosmetic colorants] of the Dyes Committee of the Deutsche Forschungsgemeinschaft [German Research Foundation], Verlag Chemie, Weinheim, 1984, pages 81 to 106.
It is in addition preferable in accordance with the invention that, when component 2) of the formulation according to the invention is selected from the group of UV light protection filter substances, pigments selected from titanium dioxide and zinc oxide are additionally present as component 2. In this connection too, the UV light protection filter substances that are preferably present correspond to the preferred UV light protection filter substances mentioned above.
A preferred formulation according to the invention is characterized in that component 1) is present in an amount of 0.1% by weight to 20% by weight, preferably of 0.25% by weight to 12% by weight, more preferably of 0.5% by weight to 6% by weight, and component 2) is present in an amount of 0.1% by weight to 60% by weight, preferably of 1% by weight to 50% by weight, more preferably of 3% by weight to 40% by weight.
The formulations according to the invention can comprise for example at least one further additional component selected from the group comprising
Substances that can be used as exemplary representatives of the individual groups are known to those skilled in the art and can for example be taken from German application DE102008001788.4. This patent application is hereby incorporated as reference and is thus considered to form part of the disclosure.
As regards further optional components and also the amounts used of these components, reference is expressly made to the relevant handbooks known to those skilled in the art, for example K. Schrader, “Grundlagen und Rezepturen der Kosmetika” [Fundamentals and formulations of cosmetics], 2nd edition, pages 329 to 341, Hüthig Buch Verlag, Heidelberg.
The amounts of the respective additives depend on the intended use.
Typical starting formulations for the relevant applications are known prior art and are contained for example in the brochures of the manufacturers of the relevant base materials and active substances. These existing formulations can generally be adopted unchanged. However, any desired modifications necessary for adjustment and optimization can be made in a straightforward manner through simple tests.
Formulations according to the invention may for example be used in the form of an emulsion, a suspension, a solution, a cream, a salve, a paste, a gel, an oil, a powder, an aerosol, a stick, a spray, a cleansing product, a make-up product or a sun protection product.
The present invention further provides for the use of the polyglycerol partial esters of the invention, or of the polyglycerol partial esters obtainable by the method of the invention, as film formers.
The present invention further provides for the use of the polyglycerol partial esters of the invention, or of the polyglycerol partial esters obtainable by the method of the invention, to boost the sun protection factor of UV light protection filter substances.
The present invention further provides for the use of the polyglycerol partial esters of the invention, or of the polyglycerol partial esters obtainable by the method of the invention, to reduce the rinseability and/or the wear of a formulation from a surface.
In the use according to the invention, preference is given to using the components mentioned above as components that are preferably present in the context of the formulations according to the invention.
The examples that follow describe the present invention by way of example without any intention to limit the invention, the scope of application of which is apparent from the entirety of the description, to the embodiments specified in the examples.
Melting points were determined using the capillary method based on DIN 53181, DIN EN ISO 3148, DGF C-IV 3a and Ph. Eur. 2.2.14.
The degree of esterification of all OH groups can be determined via the hydroxyl value, the acid value and the saponification value according to the following formula:
Degree of esterdfication=100(SV−AV)/(SV−AV+OHV)
where SV=saponification value, AV=acid value and OHV=hydroxyl value.
Suitable detection methods for determining the saponification value are in particular those according to DGF C-V 3, DIN EN ISO 3881 and Ph. Eur. 2.5.6.
Suitable methods for determining the acid value are in particular those according to DGF C-V 2, DIN EN ISO 2114, Ph. Eur. 2.5.1, ISO 3882 and ASTM D 974.
Suitable detection methods for determining the hydroxyl value are in particular those according to DGF C-V 17 a (53), Ph. Eur. 2.5.3 Method A and DIN 53240.
Ratio of the Raw Materials:
The molar ratio of polyglycerol a) to the sum total of dicarboxylic acid components b1) and b2) to carboxylic acid component c) is abbreviated to PG:Di:Mono.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 88.16 g, 0.253 mol), sebacic acid (202 g/mol, 13.88 g, 0.088 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 38 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 580 g/mol. 37.31 g. 0.068 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 1.9 mg KOH/g; saponification value: 176 mg KOH/g; hydroxyl value: 110 mg KOH/g; degree of esterification: 61.3%; melting point: 62° C.; HLB: 4.7. PG:Di:Mono=1.3:1:1.9
A mixture of polyglycerol (OHV=972 mg KOH/g. 80.86 g. 0.179 mol), behenic acid (92%, 340 g/mol. 88.16 g. 0.253 mol), sebacic acid (202 g/mol, 13.88 g, 0.088 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 580 g/mol, 37.31 g, 0.068 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 2.8 mg KOH/g; saponification value: 138 mg KOH/g; hydroxyl value: 246 mg KOH/g; degree of esterification: 35.1%; melting point: 68° C.; HLB: 7.4.
PG:Di:Mono=1.3:1:1.9.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 94.77 g, 0.279 mol), sebacic acid (202 g/mol, 13.88 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 580 g/mol, 37.31 g, 0.068 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 2.1 mg KOH/g; saponification value: 188 mg KOH/g; hydroxyl value: 82 mg KOH/g; degree of esterification: 69.4%; melting point: 64° C.; HLB: 4.5.
PG:Di:Mono=1.3:1:2.1.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 77.54 g, 0.228 mol), sebacic acid (202 g/mol, 13.88 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg 30 KOH/g, 580 g/mol. 37.31 g. 0.088 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 3.3 mg KOH/g; saponification value: 168 mg KOH/g; hydroxyl value: 80 mg KOH/g; degree of esterification: 67.3%; melting point: 63° C.; HLB: 4.9.
PG:Di:Mono=1.3:1:1.7.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol. 86.16 g. 0.253 mol), adipic acid (146 g/mol, 10.02 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 580 g/mol, 37.31 g, 0.066 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 4 mg KOH/g; saponification value: 172 mg KOH/g; hydroxyl value: 96 mg KOH/g; degree of esterification: 63.6%; melting point: 64° C.; HLB: 4.8.
PG:Di:Mono=1.3:1:1.9.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 130.0 g, 0.382 mol), sebacic acid (202 g/mol, 13.88 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 560 g/mol, 37.31 g, 0.066 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of approx. 5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 6.2 mg KOH/g; saponification value: 171 mg KOH/g; hydroxyl value: 85 mg KOH/g; degree of esterification: 66.0%; melting point: 65° C.; HLB: 3.8.
PG:Di:Mono=1.3:1:2.9.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 131.3 g, 0.386 mol), sebacic acid (202 g/mol, 6.94 g, 0.034 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 560 g/mol. 18.65 g. 0.033 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 1.4 mg KOH/g; saponification value: 161 mg KOH/g; hydroxyl value: 117 mg KOH/g; degree of esterification: 57.7%; melting point: 68° C.; HLB: 4.2.
PG:Di:Mono=2.6:1:5.8.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol) and stearic acid (92%. 284 g/mol. 136.7 g. 0.481 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <15 mg KOH/g was attained. After addition of sebacic acid (202 g/mol, 13.88 g, 0,068 mol) and dimer acid (Radiacid 0977 from Oleon having about 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 560 g/mol, 37.31 g, 0.066 mol), the mixture was further heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 3.1 mg KOH/g; saponification value: 198 mg KOH/g; hydroxyl value: 38 mg KOH/g; degree of esterification: 84.4%; melting point: 51° C.; HLB: 3.7.
PG:Di:Mono=1.3:1:3.6.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.24 g, 0.176 mol), behenic acid (92%, 340 g/mol, 77.52 g, 0.227 mol), oleic acid (>72%, iodine value: 94 mg 12/g, 281 g/mol, 7.1 g, 0.025 mol), sebacic acid (202 g/mol, 13.88 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 38 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 580 g/mol, 37.31 g, 0.068 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 2 mg KOH/g; saponification value: 179 mg KOH/g; hydroxyl value: 115 mg KOH/g; degree of esterification: 60.6%; melting point: 61° C.; HLB: 4.7.
PG:Di:Mono=1.3:1:1.9.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 50.0 g, 0.208 mol) and stearic acid (92%, 284 g/mol. AV=199 mg KOH/g, 254.3 g, 0.895 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a yellowish, brittle, solid product was obtained.
Acid value: 3.8 mg KOH/g; saponification value: 176 mg KOH/g; hydroxyl value: 24 mg KOH/g; degree of esterification: 87.8%; melting point: 58° C.; HLB: 3.3.
A mixture of polyglycerol (OHV=1100 mg KOH/g, 42.2 g. 0.176 mol), palmitic acid (256 g/mol. 64.8 g. 0.253 mol), sebacic acid (202 g/mol. 13.9 g, 0.068 mol) and dimer acid (Radiacid 0977 from Oleon having approx. 36 carbon atoms, functionality=2.0, AV=192 mg KOH/g, 560 g/mol, 37.3 g, 0.066 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained.
Acid value: 1.9 mg KOH/g; saponification value: 197 mg KOH/g; hydroxyl value: 121 mg KOH/g; degree of esterification: 61.7%; melting point: 34° C.; HLB: 5.3.
PG:Di:Mono=1.3:1:1.9.
A mixture of polyglycerol (462 g/mol, 160.0 g, 0.346 mol) and succinic acid (118 g/mol, 20.4 g, 0.173 mol) with addition of catalyst KOH (0.67 g) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After addition of palmitic acid (256 g/mol, 88.7 g, 0.346 mol), the mixture was further heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of less than 5 mg KOH/g was attained. After cooling, a yellowish, soft/waxy, solid product was obtained.
Acid value: 3.1 mg KOH/g; saponification value: 149 mg KOH/g; hydroxyl value: 658 mg KOH/g; degree of esterification: 18.2%; HLB: 11.9.
PG:Di:Mono=2.0:1:2.0.
A mixture of polyglycerol (315 g/mol, 99.0 g, 0.314 mol), sebacic acid (202 g/mol, 26.0 g, 0.129 mol) and isostearic acid (285 g/mol, 135.5 g, 0.475 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <1 mg KOH/g was attained. After addition of dimer acid (575 g/mol. 54.5 g, 0.095 mol), the mixture was further heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of less than 2 mg KOH/g was attained. After cooling, a clear, yellow, liquid product was obtained.
Acid value: 0.3 mg KOH/g; saponification value: 174 mg KOH/g; hydroxyl value: 177 mg KOH/g; degree of esterification: 49.5%; HLB: 6.3.
PG:Di:Mono=1.4:1:2.1.
A mixture of polyglycerol (240 g/mol, 74.8 g, 0.312 mol), sebacic acid (202 g/mol, 21.9 g, 0.108 mol), dimer acid (575 g/mol, 84.1 g, 0.146 mol) and C16/18 fatty acid (C16/C18=approx. 50:50, 270 g/mol, 134.8 g, 0.499 mol) was heated to 240° C. with stirring and the water that formed was continuously distilled off until an acid value of <5 mg KOH/g was attained. After cooling, a light yellow, solid product was obtained.
Acid value: 2.9 mg KOH/g; saponification value: 191 mg KOH/g; hydroxyl value: 111 mg KOH/g; degree of esterification: 62.9%; melting point: 86° C.; HLB: 4.7.
PG:Di:Mono=1.2:1:2.0.
Polyglycerol partial esters (PGEs) according to the invention have the characteristic feature of a strong tendency to film formation compared to noninventive polyglycerol partial esters or noninventive commercial products. The film-forming properties in sun protection formulations can be quantitatively demonstrated by means of in-vitro SPF tests.
This was done by preparing O/W sun protection emulsions on a 200 g laboratory scale into which were incorporated the various film formers in an each time identical manner according to the recipes hereinbelow (Table 1). The emulsions were prepared according to the method known to those skilled in the art commonly used in the production of lotions.
24.5 mg of reference formulation A and of test formulations B were respectively evenly applied to and spread over polymethyl methacrylate plates (PMMA; 7.0 cm×3.5 cm, 2 μm roughness, Schönberg GmbH & Co. KG) (1 mg/cm2). For each measurement, six replicate determinations were carried out, i.e. each formulation was applied to 6 individual PMMA plates. These were left in a drying cabinet at 30° C. for 30 min, after which the SPF of the plates was determined using a Labsphere UV2000S Ultraviolet Transmittance Analyzer in accordance with Colipa Guideline (2011) with in each case 4 measurement points per PMMA plate. The individual SPF values for each PMMA plate/formulation were noted and the mean value determined. The mean SPF values for each formulation with film former were divided by the mean SPF value of formulation A without film former. The results are listed below in Table 2.
For the inventive examples, the results in Table 2 in all cases show SPF-boost values of over 1.4 (relative to reference formulation A without film former). Indeed, values comparable with the polyacrylate Tego® SP 13 Sun Up and better than with the synthetic VP/Eicosene Copolymer were achieved by the best polyglycerol partial esters according to the invention. Significantly better values compared to plant-based reference substance of the prior art were obtained.
To determine the water resistance of sun protection formulations and sun protection factors (SPF) thereof, screening studies in accordance with Colipa 2005 (Cosmetics Europe: Guidelines For Evaluating Sun Product Water Resistance, 2005) were carried out at an external, accredited test institute.
The sun protection factor of a test parson (SPFQ) before and after water-bath treatment is calculated as the ratio of the minimum erythema dose on protected skin (MEDp) and the minimum erythema dose on unprotected skin (MEDu) on the same test person: SPFi=MEDp/MEDu. The minimum erythema dose is defined here as the amount of energy necessary to produce the first clearly perceptible redness within a clearly defined area, the redness being assessed 16 h to 24 h after exposure to light using a sunlight simulator (6 Increasing UV doses with 15% progression). The sun protection factor is determined after application of 2±0.05 mg of the test formulation on 1 cm2 of skin before and after two periods of immersion in a water bath at 30±2° C. for 20 min each time. The water resistance is then obtained as the ratio of the sun protection factor after and before the water bath: WR=SPF(after water bath)/SPF(before water bath). For further retails, reference is made to the method description of the Colipa (The European Cosmetic and Perfumery Association).
Table 4 details the results of the in-vivo water resistance measurements with formulations C, D and E from Table 3. The vehicle formulation C (without film former) showed a WR value of only 34.6% and cannot therefore be considered a water-resistant sun protection formulation in cosmetics. By contrast, formulation E with inventive example 1 provided good water resistance, with a WR value of 63.6%, and could be declared “water resistant” (i.e. WR of min. 50%). The addition of the inventive product example 1 thus brought about a significant and very good improvement in the water resistance of formulation C and is even better than the comparative formulation D with the synthetic comparative example VP/Eicosene Copolymer.
The test formulations V1, V2, V3, V4, V5, V6 and V7 were investigated by a group of volunteer subjects trained in the assessment of sensory properties (N=13). The skin feel of the cosmetic formulations described in the examples in Tables 5a and 5b was determined by a so-called panel. In these tests, a defined amount of the test lotions was applied to a clearly defined area of the forearm. The volunteer subjects compared the sensory properties of the cosmetic formulations and of the respective comparative formulation without knowing the composition. Assessment was on a scale from 0 (little) to 10 (much).
Inventive examples are marked with an *.
Helianthus Annuus (Sunflower) Seed Oil)
Helianthus Annuus (Sunflower) Seed Oil)
With regard to the use properties of the polyglycerol partial esters (PGEs) of the present invention, there were differences in sensory properties compared to the blank formulation without film former and compared to a likewise natural film former of the prior art that result in an improved skin feel during and after application. The results are collated in Table 6. Compared to the blank formulation V1, in V2 the polyglycerol partial ester (PGE) of the present invention brought about a significant increase in “velvety-silkiness” skin feel during and 5 min after application. The “velvety-silkiness” during application and after 5 min is also highest compared to the natural film former counterpart in V3. The polyglycerol partial ester (PGE) of the present invention is likewise able to achieve higher spreadability and reduced tackiness after 5 min compared to the blank formulation and to the formulation comprising the natural film former counterpart. The reduced tackiness is of particular interest in sun protection formulations, because the UV filters are generally associated with high tackiness.
Both in a test formulation based on a carbomer thickener (V4) and with a natural thickener (V6), the polyglycerol partial ester (PGE) of the present invention exhibits increased “velvety-silkiness” during application and after 5 min compared to a synthetic, non-biodegradable film former (V5 and V7 respectively). Here too, reduced “tackiness” after 5 min was observed in both thickener systems. The absorption during application and after 5 min is higher with the polyglycerol partial ester (PGE) of the present invention in both thickener systems.
The following formulation examples demonstrate the usability of the inventive polyglycerol partial esters in cosmetic emulsions by way of example and do not limit the subject matter of the invention.
All percent values are unless otherwise stated percentages by weight. Production and homogenization steps are carried out according to usual methods.
If necessary, the pH is adjusted with acids or bases, this being noted accordingly in the formulation. Since the amount of acid or base needed can depend on the batches of the other ingredients, it is in the examples here often entered as q.s. (=quantum satis). It is also necessary to adjust to different pH values depending on the preservative used. Customary pH values that were used and adjusted to here in the example formulations are in the range from pH 3.5 to 5.0.
The example recipes listed hereinbelow were respectively produced with each of the inventive PGEs from examples 1 to 9.
Prunus Amygdalus Dulcis (Sweet Almond)
Zea Mays (Corn) Starch
Copernicia Cerifera (Carnauba) Wax (2442L, KahlWax)
Zea Mays (Corn) Starch
| Number | Date | Country | Kind |
|---|---|---|---|
| 22174050.9 | May 2022 | EP | regional |
