EP4734913A1

EP4734913A1 - Polyglycerol partial ester comprising oleic acid

Info

Publication number: EP4734913A1
Application number: EP24737718.7A
Authority: EP
Inventors: Jan Marian Von Hof; Tim TANTO; Sebastian Johannes BECKERS; Achim Friedrich; Juergen Meyer; Sebastian Zimmermann
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2023-06-30
Filing date: 2024-06-27
Publication date: 2026-05-06
Also published as: CN121419744A; WO2025003292A1

Abstract

The invention relates to a polyglycerol partial ester obtainable by esterification of a) a polyglycerol mixture, b) at least one dicarboxylic acid having 24 to 44, preferably 30 to 40, particularly preferably 34 to 38, carbon atoms, and c) oleic acid, characterized in that oleic acid makes up for at least 50 wt.-%, preferably at least 60 wt.-%, more preferably at least 68 wt.-% of all monocarboxylic acids esterified into the polyglycerol partial ester.

Description

Polyglycerol partial ester comprising oleic acid

Field of the invention

Prior art

EP0835862 discloses a polyglycerol partial ester of a saturated or unsaturated, linear or branched fatty acid and a polyfunctional carboxylic acid, obtainable by esterification of a polyglycerol mixture with saturated or unsaturated, linear or branched fatty acids having 12 to 22 carbon atoms and dimer fatty acids obtained by catalytic dimerization of unsaturated fatty acids having 12 to 22 carbon atoms and have a mean functionality of from 2 to 2.4, the degree of esterification of the polyglycerol mixture being between 30 and 75%.

It is an objective of the invention to improve the skin sensation of formulations even further.

Description of the invention

It was found that, surprisingly, that polyglycerol partial esters as described in claim 1 solve the problem underlying the instant invention.

The present invention therefore provides a polyglycerol partial ester obtainable by esterification of a) a polyglycerol mixture, b) at least one dicarboxylic acid having 24 to 44, preferably 30 to 40, particularly preferably 34 to 38, carbon atoms, and c) oleic acid, characterized in that oleic acid makes up for at least 50 wt.-%, preferably at least 60 wt.-%, more preferably at least 68 wt.-% of all monocarboxylic acids esterified into the polyglycerol partial ester. The invention further provides a method for preparing a polyglycerol partial ester, comprising the method steps of

A) providing a polyglycerol, preferably having an average degree of condensation N of 2.4 to 6.0, preferably 2.6 to 4.5, especially 2.8 to 3.4,

B) providing a carboxylic acid mixture comprising: at least one dicarboxylic acid having 24 to 44, preferably 30 to 40, particularly preferably 34 to 38, carbon atoms, and oleic acid,

C) esterifying the polyglycerol with the carboxylic acid mixture, characterized in that said oleic acid makes up for at least 50 wt.-%, preferably at least 60 wt.-%, more preferably at least 68 wt.-% of all monocarboxylic acids present in said carboxylic acid mixture.

An advantage of the present invention is that the polyglycerol partial esters described herein may be prepared from exclusively renewable raw materials.

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.

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 more 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 skinmoisturizing effect.

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. One advantage of the present invention is that formulations based on polyglycerol partial esters described herein can be prepared by a cold process without heating.

Another advantage of the present invention is that the polyglycerol partial esters according to the invention are very tolerant towards different oil phase contents in the emulsions.

A further advantage is that the polyglycerol partial esters according to the invention are very tolerant towards different oil phase compositions in the emulsions.

Another advantage is that the polyglycerol partial esters according to the invention have a pleasant, less “technical” odor.

Another advantage of the present invention is that even high proportions of natural oils such as almond oil are well stabilized in emulsions.

Another advantage of the present invention is that emulsions can be stabilized over a wide viscosity range from sprays to lotions to creams.

A further advantage of the present invention is that emulsions based on emulsifiers according to the invention have very good compatibility with propellants, such as mixtures of propane, n-butane and iso-butane, and thus simplify the production of aerosol systems.

A further advantage of the present invention is that the skin feel of the emulsions stabilized with the described polyglycerol partial esters is at least as good as with the emulsifiers of the prior art. Another advantage is that the present invention can be used as emulsifier and lubricity additive for metalworking fluids (neat oils or water based fluids) where it provides excellent emulsion stabilizing properties, reduces oil droplet coalescence, increases lubricity properties e.g. of base oils especially at high frictions, is soluble even in GTL oils, gives best additional lubricity under stress, and reduces applied torque during tapping. Further, the present invention provides excellent stability of rolling oil emulsions with reduced coalescence, good lubricity, and good surface quality. Another advantage is that the present invention can be used as friction modifiers for lubricants. Another advantage is that the present invention can reduce the friction coefficient.

Another advantage is that the present invention can lead to more efficient friction reduction due to a lower treat rate and/or a better combination of oil compatibility and friction reducing performance.

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 , 875-896.

The same applies to the term “polyglycerol partial ester” in the context of the present invention.

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 acid, it will be apparent to those skilled in the art that the molar ratio of polyglycerol a) to dicarboxylic acid component b) to carboxylic acid component c) does not relate 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.

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. For the present invention, it is preferred that the polyglycerol esterified into the polyglycerol partial ester has an average degree of condensation N of 2.4 to 6.0, preferably 2.6 to 4.5, especially 2.8 to 3.4.

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 esterified into the polyglycerol partial ester has a glycerin 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 esterified into the polyglycerol partial ester.

The stated percentages by weight are determined by the GC method described hereinbelow.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the polyglycerol esterified into the polyglycerol partial ester 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 esterified into the polyglycerol partial ester.

It is advantageous when the polyglycerol esterified into the polyglycerol partial ester has a polydispersity index of more than 0.6, 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.

Conditions:

Injector: 290°C, split 30 ml

Injected volume: 1 pl

Column: 30 m * 0.32 mm HP1 0.25 pm

Carrier gas: Helium, inlet pressure 70 kPa

Temp, program: 80°C to 300°C at 8°C/min;

Detector: FID at 320°C

Hydrogen 35 ml/min

Air 240 ml/min

Make-up gas (purge gas) 35 ml/min

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 pl 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:

Injector: On-column injection (direct injection onto column)

Injected volume: 0.1 pl Carrier gas: 3 ml/min hydrogen (constant flow)

Column: SimDist 12 m x 0.32 mm x 0.1 m (Varian)

Temperature program: 65°C to 365°C, 10°C/min

Detector (FID): 375°C

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 polyglycerol esterified into the polyglycerol partial ester 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, where the percentages by weight are based on the total amount of polyglycerol esterified into the polyglycerol partial ester.

The stated percentages by weight are determined by the GC method described above.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from those obtainable from the dimerization of oleic acid and/or linoleic acid.

The mixtures obtainable from such a process known as dimer fatty acids can comprise not only the long-chain acyclic and cyclic dicarboxylic acids but also, to a minor extent, monomeric fatty acids as well as polymeric fatty acids (trimeric and higher functional), which in turn contribute to the proportion of the carboxylic acid mixture used which is not encompassed by components a) to d). The functionality of the mixture obtainable from the dimerization of oleic acid and/or linoleic acid should preferably not exceed, on molar average, a value of 2.4. For the preparation and use of dimer fatty acids and the physical and chemical properties thereof, reference is also 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 composition of the dimer acid can be determined according to AOCS Ce 2-66.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that have a monomeric acid content of 0.001% by weight to 15% by weight, preferably of 0.01% by weight to 10% by weight, more preferably of 0.05% by weight to 8% by weight.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that have a dimeric acid content of 80% by weight to 99.95% by weight, preferably of 85% by weight to 99.5% by weight, more preferably of 90% by weight to 99.0% by weight.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that have a trimeric acid content of 0.001% by weight to 15% by weight, preferably of 0.01% by weight to 10% by weight, more preferably of 0.01% by weight to 8% by weight.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that have an acid value of 180.0 mg KOH/g to 215.0 mg KOH/g, preferably of 187.0 mg KOH/g to 205.0 mg KOH/g, more preferably of 190.0 mg KOH/g to 202.0 mg KOH/g.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that have an iodine value of 0.01 g 1/100 g to 45.0 g 1/100 g, preferably of 0.1 g 1/100 g to 35.0 g 1/100 g, more preferably of 0.5 g 1/100 g to 25.0 g 1/100 g.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the long-chain dicarboxylic acid is selected from dimer acids that are at least partially hydrogenated.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the oleic acid is provided in form of a technical grade oleic acid, e.g. with an overall content of oleic acid referring to all fatty acids contained in the technical grade oleic acid mixture of at least 60 wt.- %, preferably of at least 65 wt.-%, even more preferably of at least 68 wt.-%.

Preferably the above technical grade oleic acid mixture has an overall content of linoleic (C18:2) fatty acid of from 10.0 wt.-% to 15.0 wt.-% referring to all fatty acids contained in the technical grade oleic acid mixture. Polyglycerol partial esters preferred in accordance with the invention are characterized in that the molar ratio of the oleic acid esterified into the polyglycerol partial ester and the at least one dicarboxylic acid esterified into the polyglycerol partial ester is in the range of

2.8 : 1.0 to 5.0 : 1.0, preferably 3.0 : 1.0 to 4.8 : 1.0, more preferably 3.2 : 1.0 to 4.5 : 1.0.

The molecular weight of the dicarboxylic acid in case it is a dimer acid can be calculated from its acid value and its average functionality.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that they have a degree of esterification of 35% to 95%, preferably of 40% to 85%, more preferably of 45% to 75%, more preferably of 50% to 65%.

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:

100 ■ (SV - AV)

Degree of esterification = - - -

" ^{1 1} 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 3681 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 3682 and ASTM D 974.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that the sum of the components b) and c) makes up at least 65 wt.-%, preferably at least 70 wt.-%, more preferably at least 75 wt.-%, more preferably at least 80 wt.-%, of all carboxylic acids esterified into the polyglycerol partial esters according to the instant invention.

It is particularly preferable that the polyglycerol partial ester of the invention has an acid value within a range from 0.1 mg KOH/g to 25.0 mg KOH/g, preferably within a range from 0.5 mg KOH/g to 15.0 mg KOH/g, preferably within a range from 1.0 mg KOH/g to 11.0 mg KOH/g. 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 7.0, preferably from 3.0 to 6.0 and more preferably from 4.0 to 5.0.

The HLB value is a measure of 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 dicarboxylic acid and oleic acid). For example, the esterification of 100 g of polyglycerol with 90 g of oleic 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 of the degree of polymerization of the polyglycerol and the nature of the carboxylic acids used.

Polyglycerol partial esters preferred in accordance with the invention are characterized in that they have an iodine value of 35.0 to 70.0, preferably 40.0 to 65.0, more preferably of 45.0- 60.0 g 1/100 g.

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 viscosity at 25 °C of 1000 to 25000 mPas, preferably 5000 to 20000 mPas, more preferably 7500 to 15000 mPas.

A suitable method for determining the viscosity is using a Brookfield RV viscometer (with spindle SC4-21 , running at 20 RPM and displaying a % torque of 53.0; torque constant = 1 , spindle multiplier constant = 5, spindle shear rate constant = 0.93) and a Brookfield Thermosel.

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

C) esterifying the polyglycerol with the carboxylic acid mixture. In the method according to the invention, preference is given to using those polyglycerols, dicarboxylic acids and oleic acid 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 acid 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 acid in a second step. However, the reverse stepwise synthetic sequence comprising an initial reaction of the polyglycerol with the dicarboxylic acid 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.

In a preferred method according to the instant invention the mass of the polyglycerol (mp) provided and the mass of the carboxylic acid mixture (ma) provided is such, that (mp/(mp+ma))*20 is in the range of from 2.0 to 7.0, preferably from 3.0 to 6.0 and more preferably from 4.0 to 5.0.

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 is characterized in that it comprises a further component 2) at least one antioxidant. Preferred antioxidants, which according to the invention are preferably present in the formulation according to the invention, are chosen from the group containing, preferably consisting of, 3,5-di-tert-butyl-4-hydroxytoluene (BHT), 2-tert-butyl-4- hydroxyanisole and 3-tert-butyl-4-hydroxyanisole, tert-butylhydroquinone (TBHQ), digalloyl trioleate, propyl gallate, octyl gallate, dodecyl gallate, mercaptoacetic acid, sodium thioglycolate, rosmarinic acid, carnosic acid, chlorogenic acid, isoascorbic acid, dexpanthenol, siderophores including catechols, hydroxamates, such as, for example, deferoxamines B, D1 , D2, E and H, citrates, cysteine and its derivatives, such as, for example, cysteine hydrochloride and acetylcysteine, ascorbic acid and its derivatives (e.g. ascorbyl glucoside, ascorbyl palmitate, ascorbyl dipalmitate, ascorbyl tetraisopalmitate, magnesium ascorbate, magnesium ascorbyl phosphate), vitamin E (a-tocopherol, p-tocopherol, y-tocopherol, 5-tocopherol and a-tocotrienol, p- tocotrienol, y-tocotrienol and 5-tocotrienol) and its derivatives (e.g. vitamin E acetate, vitamin E linoleate, vitamin E nicotinate, vitamin E succinate), hesperetin, naringenin, flavonoids, taxifolin, catechin, epicatechin, resveratrol and its derivatives (in particular its oligomers), carotenoids (e.g. lycopene, p-carotene, lutein), isosakuranetin, quercetin, eriodictyol, aromadendrin, acacetin, luteolin, kaempferol, apigenin, diosmetin, chrysoeriol, chrysin, galangin, limocitrin, phytic acid and its derivatives, in particular its salts.

Preferably mixtures of the abovementioned antioxidants can also be used. Particularly preferred are phytic acid and its derivatives, in particular its salts, and also vitamin E (for example in the form of a-tocopherol, p-tocopherol, y-tocopherol, 5-tocopherol, a-tocotrienol, p-tocotrienol, y-tocotrienol and/or 5-tocotrienol) and its derivatives, in particular as vitamin E acetate, vitamin E linoleate, vitamin E nicotinate or vitamin E succinate, and also their mixtures.

Preferably, the formulation according to the invention comprises a further component 2) at least a mixture of at least two different tocopherols, preferably a mixture consisting of D-alpha-Tocopherol, preferably 0 to 30% by weight, D-beta-Tocopherol, preferably 0 to 20% by weight, D-gamma- Tocopherol, preferably 40 to 80% by weight, D-delta-Tocopherol, preferably 0 to 40% by weight.

In preferred formulations according to the invention, the antioxidants are present in an amount of from 0.001% by weight to 5.0% by weight, preferably from 0.01% by 35 weight to 1.0% by weight, particularly from 0.02% by weight to 0.35% by weight, the percentages by weight referring to the total formulation.

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, if applicable, preferably component 2) is present in an amount of 0.001% by weight to 5.0% by weight, preferably from 0.01% by weight to 1.0% by weight, particularly from 0.02% by weight to 0.35% by weight, the percentages by weight referring to the total formulation.

The formulations according to the invention can comprise for example at least one further additional component selected from the group comprising emollients, emulsifiers, co-emulsifiers, thickeners/viscosity regulators/stabilizers, hydrotropes (or polyols), solids and fillers, pearlescent additives and opacifiers, insect repellents, self-tanning agents, preservatives, conditioning agents, perfumes, colorants, cosmetic active substances, care additives, refatting agents, electrolytes organic or inorganic UV filters sensory particles pigments solvents.

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, Huthig 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.

Formulations according to the instant invention preferably are emulsions, most preferably water-in- oil-emulsions, also known as w/o-emulsions. Consequently, they preferably comprise an oil phase. 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 ingredient, especially as emulsifier and/or lubricity additive, in metalworking fluids.

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 adduced hereinafter describe the present invention by way of example, without any intention that the invention, the scope of application of which is apparent from the entirety of the description and the claims, be restricted to the embodiments specified in the examples.

Example 1: (non-inventive) polyglycerol partial ester according to example 1 of EP0835862 with isostearic acid

A mixture of polyglycerol (OHV = 1180 mg KOH/g, 100.0 g), isostearic acid (Palmera IS-30 from KLK Emmerich GmbH, AV = 196 mg KOH/g, iodine value = 1.2 g 1/100 g, 264 g, 0.922 mol) was heated to 250 °C with stirring and nitrogen passing through. The resulting water was continuously distilled and after 3 h under these conditions, dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, acid value = 193.5 mg KOH/g, 121 g, 0.209 mol) was added, the mixture was heated to 250 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 1.6 mg KOH/g was reached.

Molar ratio of isostearic acid and dicarboxylic acid = 4.4 : 1.0 HLB value = 4.1

Example 2: (inventive) polyglycerol partial ester with oleic acid and dimer acid

A mixture of polyglycerol (OHV = 1180 mg KOH/g, 100.0 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 259.1 g, 0.922 mol) was heated to 240 °C with stirring and nitrogen passing through. The resulting water was continuously distilled and after 3 h under these conditions, dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, acid value = 193.5 mg KOH/g, 121 g, 0.209 mol) was added, the mixture was heated to 250 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 3.2 mg KOH/g was reached.

Molar ratio of oleic acid and dicarboxylic acid = 4.4 : 1.0 HLB value = 4.2

Example 3: (inventive) polyglycerol partial ester with oleic acid and dimer acid

A mixture of polyglycerol (OHV = 1100 mg KOH/g, 603.4 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 1426 g, 5.08 mol) and dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, acid value = 193.5 mg KOH/g, 748.3 g, 1.29 mol) was heated to 240 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 2.9 mg KOH/g was reached.

Molar ratio of oleic acid and dicarboxylic acid = 3.9 : 1.0 HLB value = 4.3

Example 4: (inventive) polyglycerol partial ester with oleic acid and dimer acid

A mixture of polyglycerol (OHV = 1100 mg KOH/g, 603.4 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 1290 g, 4.59 mol) was heated to 250 °C with stirring and nitrogen passing through. The resulting water was continuously distilled and after 3 h under these conditions, dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, acid value = 193.5 mg KOH/g, 800 g, 1.38 mol) was added, the mixture was heated to 250 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 3.3 mg KOH/g was reached.

Molar ratio of oleic acid and dicarboxylic acid = 3.3 : 1.0 HLB value = 4.5

Example 5: Sensory comparison of examples 2 and 3 and 1

To differentiate the sensorial properties of the inventive polyglycerol partial ester against the state of the art, formula 1a to 1c was prepared. The effect of the polyglycerol partial ester on the skin feel was tested by a panel of trained panelists. Each panelist applied 25 L of each formulation on a test field with defined size on his inner forearm. The formulation was homogenously distributed with a finger in circular movements. The sensory was evaluated directly after application and 5 min later.

Surprisingly formula 1 a and 1 b according to the invention differentiated from formula 1 c of the prior art by an overall richer and smoother skin feel. The following table shows the sensorial differences between the inventive emulsifiers and the benchmark:

Table 1 :

+ + very strong, + strong, 0 medium, - low, - - very low

Example 6 (inventive) polyglycerol partial ester with oleic acid and dimer acid

A mixture of polyglycerol (OHV = 1124 mg KOH/g, 48.6 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 90.2 g, 0.322 mol) and dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, AV = 193.5 mg KOH/g, 42.7 g, 0.074 mol) was heated to 240 °C with stirring and nitrogen passing through. The resulting water was continuously distilled until an acid value of 2.3 mg KOH/g was reached.

Molar ratio of oleic acid and dicarboxylic acid = 4.4 : 1.0

HLB value = 5.4

Example 7: (inventive) polyglycerol partial ester with oleic acid and dimer acid (HLB 4.6, n/n Olsaure/Dimer = 4.4)

A mixture of polyglycerol (OHV = 1100 mg KOH/g, 57.5 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 130.7 g, 0.466 mol) was heated to 240 °C with stirring and nitrogen passing through. The resulting water was continuously distilled under these conditions until an acid value of 5.7 mg KOH/g was reached. Then, dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, AV = 193.5 mg KOH/g, 61.9 g, 0.107 mol) was added, the mixture was heated to 240 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 3.0 mg KOH/g was reached. Molar ratio of oleic acid and dicarboxylic acid = 4.4 : 1.0 HLB value = 4.6

Example 8: (inventive) polyglycerol partial ester with oleic acid and dimer acid (HLB 3.5, n/n Olsaure/Dimer = 4.4)

A mixture of polyglycerol (OHV = 1100 mg KOH/g, 43.8 g), oleic acid (Palmera A1818 from KLK Emmerich GmbH, AV = 200 mg KOH/g, iodine value = 92 g 1/100 g, 140.0 g, 0.499 mol) and dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, AV = 193.5 mg KOH/g, 66.3 g, 0.114 mol) was heated to 240 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 4.7 mg KOH/g was reached. Molar ratio of oleic acid and dicarboxylic acid = 4.4 : 1.0 HLB value = 3.5 Example 9: (non-inventive)

A mixture of glycerol (500 g) and 45% aq. KOH (5.56 g) was heated to 240 °C at 400 mbar and with N2 passing through. The resulting water was continuously distilled until a refractive index of 1.4920 was reached. Then, the pressure was reduced to <10 mbar at 240 °C and the excess glycerol was removed by distillation until the resulting polyglycerol had a hydroxyl value of 1150 mg KOH/g.

A mixture of the obtained polyglycerol (OHV = 1150 mg KOH/g, 204.3 g), partially hydrogenated tallow fatty acid (Hydrofol 20 from Evonik Industries, AV = 206 mg KOH/g, iodine value = 20.1 g 1/100 g, 31% C16, 45% C18, 352.1 g, 1.29 mol) was heated to 240 °C with stirring and nitrogen passing through. The resulting water was continuously distilled under these conditions until an acid value of 7.5 mg KOH/g was reached. Then, dimer acid (Radiacid 0977 from Oleon, 36 carbon atoms, functionality = 2.0, AV = 193.5 mg KOH/g, 243.6 g, 0.420 mol) was added, the mixture was heated to 240 °C with stirring and nitrogen passing through and the resulting water was continuously distilled until an acid value of 2.6 mg KOH/g was reached.

Molar ratio of partially hydrogenated tallow fatty acid and dicarboxylic acid = 3.1 : 1.0 HLB value = 5.1

Example 10: Emulsification performance comparison of examples 2, 6, 7, 8 and 9

The emulsification performance was evaluated in formula 13. The emulsion was prepared in a hot/cold process using polyglycerol esters according to example 2, 6, 7, 8 and 9. Surprisingly the formulas containing the inventive polyglycerol esters 2 and 7 showed a higher stability than the emulsions containing emulsifiers 6 and 8 or the non-inventive polyglycerol ester according to example 9: After 1 month storage at 25°C and 45°C, the emulsions stabilized with the emulsifiers 2 and 7 remained fully stable. After performing three freeze-thaw cycles in the which the emulsion was frozen at -15°C and then thawed at room temperature, no instabilities were observed as well. An inferior emulsification performance was observed for the polyglycerol ester according to examples 6, 8 and 9, all of which showed phase separation (oil or water) upon storaging the respective formulations and after three freeze-thaw cycles.

Formulation examples:

The following examples show that the inventive emulsifier can be used for the stabilization of versatile cosmetic formulations as well as for the dispersion of pigments and other solids. Furthermore, the examples show the compatibility with typical co-emulsifiers, cosmetic oils, emollients, waxes, and stabilizers as well as the tolerance against emulsion-destabilizing components such as UV-filters, antimicrobials, electrolytes and active ingredients. The present invention is described by the examples listed below, without any intention to limit the invention, the scope of application of which arises from the entire description and the claims, to the embodiments specified in the examples. The example formulations listed below were each prepared with the polyglyceryl esters of Examples 2 and 3 according to the invention.

Cooling Body Lotion

Natural W/O cream Cold processable lotion

Moisturizing lotion with urea W/0 lotion with silky-velvety skin feel

Baby care

Foot care

Sun protection SPF 30 UVA with insect repellent

Sun protection SPF 30 UVA according to eco-criteria

Sun protection lotion with SPF 50 according to FDA-criteria

Foundation

Claims

1. Polyglycerol partial ester obtainable by esterification of a) a polyglycerol mixture, b) at least one dicarboxylic acid having 24 to 44, preferably 30 to 40, particularly preferably 34 to 38, carbon atoms, and c) oleic acid, characterized in that oleic acid makes up for at least 50 wt.-%, preferably at least 60 wt.-%, more preferably at least 68 wt.-% of all monocarboxylic acids esterified into the polyglycerol partial ester.

2. Polyglycerol partial ester according to Claim 1 , characterized in that the polyglycerol esterified into the polyglycerol partial ester has a glycerin 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.

3. Polyglycerol partial ester according to Claim 1 or 2, characterized in that the polyglycerol esterified into the polyglycerol partial ester has an average degree of condensation N of 2.4 to 6.0, preferably 2.6 to 4.5, especially 2.8 to 3.4.

4. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that the polyglycerol esterified into the polyglycerol partial ester 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.

5. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that the long-chain dicarboxylic acid is selected from those obtainable from the dimerization of oleic acid and/or linoleic acid.

6. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that the dicarboxylic acid is provided in the form of a dimer acid with a functionality not exceeding, on molar average, a value of 2.4.

7. Polyglycerol partial ester according to at least one of the preceding claims, in that the molar ratio of the oleic acid esterified into the polyglycerol partial ester and the at least one dicarboxylic acid esterified into the polyglycerol partial ester is in the range of

8. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that it has a HLB value of from 2.0 to 7.0, preferably from 3.0 to 6.0 and more preferably from 4.0 to 5.0.

9. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that it has an iodine value of 35.0 g 1/100 g to 70.0 g 1/100 g, preferably 40.0 g 1/100 g to 65.0 g 1/100 g, more preferably of 45.0 g 1/100 g to 60.0 g 1/100 g

10. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that it a degree of esterification of 35% to 95%, preferably of 40% to 85%, more preferably of 45% to 75%, more preferably of 50% to 65%.

11. Polyglycerol partial ester according to at least one of the preceding claims, characterized in that it has a viscosity at 25 °C of 1000 to 25000 mPas, preferably 5000 to 20000 mPas, more preferably 7500 to 15000 mPas.

12. Method for preparing a polyglycerol partial ester, comprising the method steps of

C) esterifying the polyglycerol with the carboxylic acid mixture, characterized in that said oleic acid makes up for at least 50 wt.-%, preferably at least 60 wt.- %, more preferably at least 68 wt.-% of all monocarboxylic acids present in said carboxylic acid mixture.

13. Formulation, especially a cosmetic formulation, comprising

1) polyglycerol partial esters according to at least one of Claims 1 to 11 or obtainable according to the method of Claim 12, and optionally

2) at least one antioxidant.

14. Formulation according to Claim 13, characterized in that component 2) is selected from the group of vitamin E, preferably in the form of a-tocopherol, p-tocopherol, y-tocopherol, 5-tocopherol and a-tocotrienol, p-tocotrienol, y-tocotrienol and/or 5-tocotrienol.

15. Use of a polyglycerol partial ester according to at least one of Claims 1 to 11 or obtainable according to the method of Claim 12 as ingredient, especially as emulsifier and/or lubricity additive, in metalworking fluids.