EP3713538A1

EP3713538A1 - Water in oil emulsifier composition and the use thereof

Info

Publication number: EP3713538A1
Application number: EP17932010.6A
Authority: EP
Inventors: Lu Wang; Yi Sun; Xiaoling Wang; Achim Friedrich; Yan Wang; Heliang DU; Juergen Meyer; Hans Henning Wenk
Original assignee: Evonik Specialty Chemicals Shanghai Co Ltd; Evonik Operations GmbH
Current assignee: Evonik Specialty Chemicals Shanghai Co Ltd; Evonik Operations GmbH
Priority date: 2017-11-20
Filing date: 2017-11-20
Publication date: 2020-09-30
Also published as: CN111356430A; EP3713538A4; WO2019095364A1

Abstract

An emulsifier composition comprising (A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12; (B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyether polyol or polyol with a C1-C22 fatty acid, and has an HLB value from 4 to 13; and optionally (B') An additional emulsifier ingredient; and optionally (C) A particle selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms. The composition enables preparation of a stable W/O emulsion in just one-step. A use of the emulsifier composition, a stable W/O emulsion and the preparation process thereof is also provided.

Description

Water in oil emulsifier composition and the use thereof

Technical Field

The invention relates to a water in oil emulsifier composition which may be used in applications such as cosmetics.
Background art
Water in oil (W/O) emulsions, especially high inner phase content water in oil emulsions are well known for their special skin sensory, water resistance and skin moisturizing properties. To prepare a water in oil emulsion, the common method is to add water phase gradually into oil phase while stirring. If all the water phase and all the oil phase are directly mixed and then homogenized, a water in oil emulsion will not be available, even the time for homogenization is extended. Compared with the preparation process of oil in water emulsion that just needs to add oil phase into water phase in one-step and stir, this method costs more time and needs extra facilities. To some extent, the application and promotion of water in oil emulsions are blocked by such equipment requirement.
Summary of the invention
The objective of the present invention is to overcome as least part of the defects of the prior art.
The inventors have surprisingly found a new W/O emulsifier composition which enables preparation of a stable W/O emulsion in just one-step. As used herein, the term “one-step” means mixing of a water phase and an oil phase without stirring or agitation in preparation of a W/O emulsion, i.e., before homogenization to obtain a W/O emulsion, the water phase and the oil phase may be directly mixed together without stirring or agitation. Unlike the standard process of adding water phase gradually into oil phase while stirring, with the new emulsifier, the water phase can be poured into the oil phase directly without stirring. Alternatively, the oil phase can also be added to the water phase which is also not possible with the standard process. Then the obtained mixture may be homogenized to obtain a W/O emulsion. In this case, time can be saved and facility can be simplified.
According to one aspect of the present invention, it provides an emulsifier composition, specifically a W/O emulsifier composition, comprising:
(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the primary emulsifier has an HLB value of less than 12, for example 2-12, preferably from 2-9;
(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyether polyol or polyol with a C1-C22 fatty acid, and has an HLB value from 4 to 13; and optionally
(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms; and optionally
(C) A particle selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms.
The emulsifier composition may comprise the primary emulsifier and the co-emulsifier only, or comprise the primary emulsifier, the co-emulsifier and the additional emulsifier ingredient only, or comprise the primary emulsifier, the co-emulsifier and the particle only, or comprise the primary emulsifier, the co-emulsifier, the additional emulsifier ingredient and the particle only.
The HLB value throughout the present invention is determined according to the method of Griffin according to Griffin, W.C. : Classification of surface active agents by HLB, J. Soc. Cosmet. Chem. 1, 1949.
The term particles as used in context of the present invention means solid (at 25 ℃) particles that are contained in solid form in the emulsifier composition according to the present invention.
The term fatty acid in the context of the present invention preferably means straight or branched, saturated or unsaturated aliphatic carboxylic acids which may be hydroxyl-substituted.
The emulsifier composition can be used for preparation of a stable W/O emulsion in one-step (and may be called as “one-step W/O emulsifier composition” ) . With the emulsifier composition, the water phase and all the oil phase can be directly mixed together and then homogenized to prepare a stable W/O emulsion. Using the emulsifier composition, a stable W/O emulsion can be prepared conveniently with a simple process and a simple equipment, in particular same process and equipment as O/W emulsion preparation.
According to the present invention, the emulsion is stable means that the emulsion does not break nor separate by visual inspection under storage conditions particularly: 1) storage at 45℃ for at least 1 months; 2) storage at 25℃ for at least 3 month; and 3) freeze/thaw cycle: -15℃/RT (room temperature, between 20-25℃) for 3 cycles with a 24h interval between two cycles.
The components (A) , (B) , (B’) and (C) are preferably contained in the emulsifier composition according to the present invention in an amount of
(A) : 30 wt-%to 90 wt-%;
(B) : 1 wt-%to 40 wt-%;
(B’) : 0 wt-%to 8 wt-%;
(C) : 5 wt-%to 30 wt-%;
wherein the weight percentages refer to the total emulsifier composition.
The emulsifier composition with particles could be a paste if the components are mixed together, or a clear and stable liquid with precipitated particles if the components are not mixed together.
The primary emulsifier may be a mixture. Likewise, the co-emulsifier may also be a mixture.
Preferably, the primary emulsifier constitutes 30-90wt-%, preferably 40-80wt-%, for example 50-80wt-%, 55-80wt-%, the co-emulsifier constitutes 1-45wt-%, for example 1-40wt-%, 1.5-40wt-%, 1.5-35wt-%, 1.5-30wt-%, preferably 2-35wt-%, 5-35wt-%, 5-35wt-%, 10-35wt-%, the particle constitutes 0-45wt-%, for example 0-40wt-%, 0-35wt-%, 0-30wt-%, 0-25wt-%, 0-20wt-%, 5-45wt-%, 5-40wt-%, 5-35wt-%, 5-30wt-%, 5-25wt-%, 5-20wt-%, preferably 10-40wt-%, for example 10-30wt-%, 10-25wt-%, 10-20wt-%, based on the total weight of the emulsifier composition.
Primary emulsifier
The primary emulsifier is selected from surfactants having an HLB value less than 12, for example 2-12, preferably from 2-9.
Preferably, the primary emulsifier can be selected from polysiloxane emulsifiers, for example an emulsifier having a molecular chain structure of polysiloxane + a hydrophilic group + an alkyl; preferably, the emulsifier comprises a polysiloxane chain as the main chain, and polyether polyol and C1-C22 aliphatic alkyl as side groups which are respectively connected to the main chain of polysiloxane by covalent bonds, the side groups could be C1-C22 aliphatic alkyl modified polyether polyol.
Suited polysiloxanes are depicted in the following general formula (I)
wherein R¹ is selected from alkyl groups with 8 to 18 carbon atoms, preferred linear alkyl groups, R² is selected from alkyl groups with 1 to 6 carbon atoms, preferred linear alkyl groups, and H, x=1-200, y=1-200, n=1-200, o=1-100, m=1-40.
More preferably, the emulsifier could be Cetyl PEG/PPG-10/1 Polydimethylsiloxane (for example the ones supplied under the trade names ofEM 90 andEM180 by Evonik Nutrition &Care GmbH) .
The Cetyl PEG/PPG-10/1 Dimethicone (for example the one supplied under the trade name ofEM 90 by Evonik Nutrition &Care GmbH) can have the following structure formula (II) :
wherein R is a cetyl group, x=10, y=1, n=1-200, o=1-100, m=1-40, which may have a molecular weight of 12000 to 16000 g/mol.
Alternatively preferred siloxanes contained as primary emulsifiers are crosslinked siloxanes characterized in that they have organopolysiloxane units linked by building blocks of the following formula (III) :
-CH₂-CH₂- (G) _nO (EO) _x (PO) _y (XO) _z- (III)
wherein
G=divalent organic radical, preferably CH₂, C═O, CR⁵ ₂ or CHR⁵, preferably CH₂,
EO=C₂H₄O,
PO=C₃H₆O,
XO=C₂H₃R⁵O,
n=1 to 16, preferably 1 to 9 and more preferably 1,
x=2 to 50, preferably 5 to 30, preferably from 6 to 15,
y=0 to 50, preferably 0 or >0 to 15, preferably 0,
z=0 to 10, preferably 0 or >0 to 2, preferably 0,
R⁵=independently of one another, identical or different radicals selected from the group comprising alkyl radicals having 2 to 16 carbon atoms, which are optionally interrupted by ether functions, alkaryl radicals having 7 to 18 carbon atoms, aryl radicals having 6 to 16 carbon atoms, preferably ethyl or phenyl, wherein the building blocks of the above formula (III) are directly linked to an Si atom at both linkage points.
Preferably, each crosslinked siloxanes unit has, on average, more than 1, preferably from 1 to 10, preferably from 1.1 to 5 and particularly preferably from 1.5 to 4, linkage points to a building block of the above formula (III) .
In the crosslinked siloxanes the organopolysiloxane units are preferably identical or different units of the formula (IV)
M_2+c+2d D_a D’_b T_c Q_d (IV)
wherein
M= (R¹R² ₂ SiO_1/2) ,
D= (R² ₂ Si O_2/2) ,
D’= (R²R³ Si O_2/2) ,
T= (R² Si O_3/2) ,
Q= (Si O_4/2) ,
a = 30 to 800, preferably 40 to 500, preferably 50 to 400, particularly preferably 75 to 150,
b = 1 to 40, preferably 3 to 35, preferably 20 to 30,
c = 0 to 2, preferably 0 or > 0 to 1, preferably 0.05 to 0.2, particularly preferably about 0.1,
d = 0 to 2, preferably 0 or > 0 to 1, preferably 0,
R¹= R² or R³,
R²= independently of one another, V or H or identical or different linear or branched, optionally aromatic hydrocarbon radicals having 1 to 32, preferably 6 to 25, carbon atoms, which optionally carry OH or ester functions, preferably C₉-, C₁₂-, C₁₆-or C₂₂-hydrocarbon radical or methyl radical or phenyl radical, in particular methyl radical,
R³= independently of one another, identical or different polyether radicals of the general formula (V)
-CH₂-CH₂- (G) _nO (EO) _x (PO) _y (XO) _z R⁴ (V)
wherein
G= divalent organic radical, preferably CH₂, C=O, CR⁵ ₂ or CHR⁵, preferably CH₂,
EO= (-C₂H₄O-) ,
PO= (-C₃H₆O-) ,
XO = (C₂H₃R⁵O) ,
n = 1 to 16, preferably 1 to 9 and more preferably 1,
x = 2 to 50, preferably 5 to 30, preferably from 6 to 15,
y = 0 to 50, preferably 0 or > 0 to 15, preferably 0,
z = 0 to 10, preferably 0 or > 0 to 2, preferably 0,
R⁴= independently of one another, identical or different radicals selected from the group comprising H, alkyl radicals having 1 to 16 carbon atoms, or carboxylate radicals, preferably comprising 2 to 22 carbon atoms, and
R⁵ = independently of one another, identical or different radicals selected from the group comprising alkyl radicals having 2 to 16 carbon atoms, which are optionally interrupted by ether functions, alkaryl radicals having 7 to 18 carbon atoms and aryl radicals having 6 to 16 carbon atoms, preferably ethyl or phenyl, and
V = a bond (alinkage point) to the building block of the formula (III) , where at least one V is present per organopolysiloxane unit (IV) .
Preferably, radical R² is a bond V only in the units M and D. The radical R² is preferably not a hydrogen atom.
The average number of linkage points V per unit of formula (IV) is preferably more than or equal to 1, preferably 1 to 5 and more preferably 1 to 2.
Methods for preparation of these crosslinked siloxanes can be found for example in US2011070183A1.
Co-emulsifier
The co-emulsifier is selected from surfactants having an HLB value from 4 to 13, preferably an HLB value from 5-13.
The co-emulsifier can be an ester formed by a polyether polyol or a polyol and a C1-C22 fatty acid. The fatty acid may be straight or branched, saturated or unsaturated fatty acid.
Preferably, the fatty acid is selected from C12-C18 fatty acids, for example lauric acid, isostearic acid, stearic acid, myristic acid, oleic acid and palmitic acid.
Preferably, the polyether polyol or polyol is selected from sorbic alcohol, sorbitan, mono-or poly-glycerol, polyethylene glycol and poly (propylene glycol) , for example, selected from polyols with 3-6 carbon atoms and 3-6 hydroxyl groups, more preferably sorbic alcohol or sorbitan or selected from polyglycerol with a polymerization degree of 1 to 10, preferably 2 to 6.
The co-emulsifier preferably can be selected from at least one of the following groups:
B1) sorbitan or sorbitol partial esters, preferably preparable by esterification of aliphatic, linear or branched, optionally unsaturated and/or hydroxy-functionalized carboxylic acids with a chain length of from 6 to 22 carbon atoms with sorbitol,
B2) glycerol and polyglycerol partial esters, preferably preparable by esterifying aliphatic, linear or branched, optionally unsaturated and/or hydroxy-functionalized carboxylic acids with a chain length of from 6 to 22 carbon atoms with glycerol, polyglycerols or mixtures of the two.
In some embodiments, the co-emulsifier is an ester formed by a polyol with 3-6 carbon atoms and 3-6 hydroxyl groups, and a C12-C18 fatty acid.
For example, the co-emulsifier can be selected from:
sorbitan laurate (for example, the one supplied under the trade name ofSML by Evonik) ,
the combination of sorbitan laurate, polyglyceryl-4 laurate and dilauryl citrate (for example, the one supplied under the trade name of Care LTP by Evonik) ,
polyglyceryl-4 laurate,
polyglyceryl-3 stearate (for example, the one supplied under the trade name ofCare PSC 3 by Evonik) ,
polyglyceryl-4 isostearate (for example, the one supplied under the trade name ofGI 34 by Evonik) ,
glyceryl stearate (or example, the one supplied under the trade name of4100 Pellets by Evonik) , and
the mixture of glyceryl monostearate and polyoxyethylene stearate (for example, the one supplied under the trade name ofCare 165 by Evonik, INCI name: glyceryl stearate; PEG-100 stearate) .
The co-emulsifier may optionally be used together with one or more additional emulsifier ingredients. Therefore, the emulsifier composition may optionally comprise (B’) an additional emulsifier ingredient, which is preferably selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms, as mentioned in EP1790327A. With (B’) additional emulsifier ingredient present, the prepared emulsion with the emulsifier composition may have increased stability.
Preferably, the additional emulsifier ingredient is selected from citric acid partial esters carrying neutralizable acid functions or citric acid partial esters carrying acid functions, at least partially neutralized, of aliphatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols with a chain length of from 6 to 22 carbon atoms.
Preferably, the additional emulsifier ingredient constitutes 1 to 20 wt-%, for example 3 to 10 wt-%of the weight of the co-emulsifier.
Particle
The particle can be selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms.
The fatty acid of the metal salt in the particle is not limited to straight or branched, saturated or unsaturated fatty acids.
More preferably, the fatty acid of the metal salt in the particle is selected from C12-C18 fatty acids, for example lauric acid, isostearic acid, stearic acid, isosteric acid, myristic acid, oleic acid and palmitic acid.
Preferably, the metal of the metal salt in the particle is selected from Ba, Mg, Al, Zn, and Ca.
When silica particles are used as the particle, i.e., component (C) of the emulsifier composition, the particle may further comprise a plant or animal wax, for example a Candelilla wax.
Preferably, the silica particles are selected from hydrophobic silicas, especially with a mean particle size of 10 nm to 6500 nm.
Hydrophobic silica are silica which carry chemically bonded groups selected from alkyl-groups and alkylsubstituted siloxane chains.
The mean particle size d₅₀ is preferably determined by light scattering in a laser beam with a Malvern Mastersizer 2000. The determination is done using the dry measurement. Each time 20 to 40 g powder are fed using a Scirocco dry powder feeder. The particle flow is controlled operating the vibrating tray with a feed-rate of 70 %. The dispersive air pressure is adjusted to be 3 bar. Each measurement is accompanied by a measurement of the background (10 seconds /10,000 single measurements) . The measurement time of the sample is 5 seconds (5,000 single measurements) . The refraction index as well as the blue light value are fixed to be 1.52. The evaluation is done using the Mie-theory.
In some embodiments, the invention provides an emulsifier composition, which is comprised of, or is essentially comprised of:
(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12 for example 2-12, preferably from 2-9;
(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyether polyol or polyol with a C1-C22 fatty acid, and has an HLB value from 4 to 13; and optionally
(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms; and optionally
(C) A particle selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms.
The term “the composition is essentially comprised of” in context of the instant invention means that the sum of all listed components [above (A) , (B) , (B’) , and (C) ] make up for at least 95 wt. -%, preferably 98 wt. -%, of the total composition.
In this embodiment the components (A) , (B) , (B’) and (C) are preferably contained in an amount of
(A) : 40 wt-%to 80 wt-%;
(B) : 1 wt-%to 30 wt-%;
(B’) : 0 wt-%to 2 wt-%;
(C) : 10 wt-%to 30 wt-%;
wherein the weight percentages refer to the total emulsifier composition.
In some embodiments, the invention provides an emulsifier composition, which is comprised of, or is essentially comprised of:
(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12 for example 2-12, preferably from 2-9;
(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyol with 3-6 carbon atoms and 3-6 hydroxyl groups and a C12-C18 fatty acid, and has an HLB value from 4 to 13 and optionally
(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms.
In this embodiment the components (A) , (B) and (B’) are preferably contained in an amount of
(A) : 50 wt-%to 80 wt-%;
(B) : 20 wt-%to 30 wt-%;
(B’) : 0 wt-%to 2 wt-%;
wherein the weight percentages refer to the total emulsifier composition.
According to another aspect of the present invention, there is provided a water in oil emulsion, comprising:
(1) an oil phase;
(2) a water phase; and
(3) the emulsifier composition of the present invention.
The water in oil emulsion may be free of some particular ingredients required in some prior art. Moreover, the water in oil emulsion may be comprised of, or be essentially comprised of components (1) , (2) , and (3) .
Preferably, the oil phase constitutes 15-69wt-%, for example 15-69wt-%, 15-68wt-%, 15-67wt-%, 15-66wt-%, 15-65wt-%, 15-60wt-%, 15-50wt-%, preferably 20-50wt-%, the water phase constitutes 30-82wt-%, for example 30-81wt-%, 40-82wt-%, 50-82wt-%, 60-82wt-%, 30-80wt-%, 40-80wt-%, 50-80wt-%, 60-80wt-%, preferably 50-70wt-%, the emulsifier composition constitutes 1-10wt-%, for example 1-9wt-%, 1-8wt-%, 1-7wt-%, 1-6wt-%, 1-5wt-%, 1.2-10wt-%, 1.2-9wt-%, 1.2-8wt-%, 1.2-5wt-%, 1.2-5wt-%, preferably 2-5wt-%, based on the total weight of the emulsion.
The oil phase may comprise one or more oil phase components, for example oil. The oil phase components are preferably liquid. The oil phase contains at least one oil. If two or more oils are comprised in oil phase, the different oils should have good compatibility or be compatible to each other. Oil of the emulsion may be selected from the group of:
1) Synthetic or naturally derived esters or ethers, for instance oils of formula RaCOORb and RaORb in which Ra represents a fatty acid residue containing from 4 to 29 carbon atoms and Rb represents a branched or unbranched hydrocarbon-based chain containing from 3-30 carbon atoms, such as, for example, diethylhexyl carbonate, C12-15 alkyl benzoate (TN from Evonik) , isopropyl palmitate, isopropyl myristate; polyol esters, for instance propylene glycol dioctanate. Natural ones such as hydrocarbon-based oils of animal and/or plant origin, including castor oil, corn oil, jojoba oil, avocado oil, caprylic/capric acid triglycerides and so on; and
2) Linear or branched hydrocarbons of mineral or synthetic origin which are commonly used in cosmetic field, such as, isohexadecane, mineral oil.
Silicone oils which are commonly used in cosmetic field can also be used together with one or more oils above. Examples of the silicone oil may be selected from cyclomethicone; cyclohexasilxane; dimethicone (e.g., from Evonik) for example, the product sold under the nameFluid by Dow Corning.
Preferably, the oil is one or more selected from fatty hydrocarbons, esters and ethers.
More preferably, the oil is one or more selected from methyl laurate, n-hexyl laurate, 2-ethylhexyl laurate, methyl stearate, isopropyl stearate, n-butyl stearate, octyl stearate, isooctyl stearate, 2-hexyldecyl stearate, steryl heptanoate, methyl oleate, isopropyl oleate, decyl oleate, oleyl oleate, erucyl oleate, decyl lioleate, stearyl heptanoate, isopropyl myristate, myristyl myristate, isopropyl palmitate, octyl palmitate, isononyl palmitate, cety palmitate, 2-ethylhexyl palmitate, octyldodecyl 2-palmitate, isononyl isononanoate, cetearyl isononanoate, methyl erueate, oleyl erueate, cetyl ethylhexanoate, cetearyl ethylhexanoate, cetyl ricinoleate, and diisooctyl carbonate, di-n-butyl adipate, di-n-butyl sebacate, di (2-ethylhexyl) adipate, di (2-hexyldecyl) succinate or di-iso-tridecyl azalaate, diethylhexyl carbonate, ethylene glycol dioleate, ethylene glycol diisotridecanoate, propylene glycol di (2-ethylhexanoate) , butylene glycol diisostearate, neopentyl glycol dioctoate, decyl cocoate, isocetyl palmitate, triglycerides of the mixture of octanoic acid/decanoic acid, triglycerides of industrial oleic acid, triglycerides of isostearate, triglycerides of the mixture of palmitic acid/oleic acid, caprylic/capric triglyceride, 12-15 alkyl benzoate, isostearyl benzoate, octyldodecyl benzoate, oleyl alcohol, cetyl alcohol, stearyl alcohol, octyldodecanol, polypropylene glycol-15 stearyl ether, polypropylene glycol-14 butyl ether, polypropylene glycol-3 myristyl ether, polypropylene glycol-11 stearyl ether, dioctyl ether, PPG-11 stearyl ether, PPG-15 stearyl ether, PPG-14 butyl ether, PPG-3 miristyl ether, paraffin oil, white mineral oil, isohexadecane, polyisobutene, polydecene, petroleum jelly, light liquid paraffin, squalane, olive oil, sunflower seed oil, soybean oil, peanut oil, rapeseed oil, almond oil, palm oil, jojoba oil, coconut oil, liquid fraction of palm shell oil, spermaceti oil, neatsfoot oil, and liquid fraction of tallow oil.
The water phase comprises water and optionally one or more other water phase components such as a water miscible alcohol, preferably the water miscible alcohol is one or more selected from monohydric alcohols, diols or triols, more preferably the water miscible alcohol is one or more selected from 1, 2-proplyene glycol, 1, 3-propylene glycol and glycerin.
Preferably, the water in oil emulsion further comprises at least one water soluble electrolyte in the water phase, preferably the electrolyte is one or more selected from sodium chloride, potassium chloride, sodium citrate, sodium lactate, magnesium sulfate, calcium chloride and salts of amino acids.
Optionally, the water in oil emulsion further comprises at least one water soluble functional additive for cosmetics in the water phase, for example, those supplied by Evonik Industries under the trade names COSMO C 100, andNATURAL BETAIN.
The emulsions according to the invention can further comprise at least one additional component selected from the group of:
UV light protection filters,
Antioxidants,
Solids and fillers.
Preservatives,
Perfumes,
Dyes, and
Cosmetic active ingredients.
Substances which can be used as exemplary representatives of the individual groups are known to the person skilled in the art and can be found for example in the German application DE 102008001788.4. This patent application is herewith incorporated as reference and thus forms part of the disclosure.
According to another aspect of the present invention, there is provided use of the emulsifier composition of the present invention in preparation of a stable water in oil emulsion in one-step.
According to another aspect of the present invention, there is provided a process to prepare a stable water in oil emulsion, comprising:
1) mixing the emulsifier composition according to the present invention or ingredients of the emulsifier composition according to the present invention with at least one oil phase component to obtain a mixture;
2) mixing a water phase directly with the mixture obtained in Step 1) in one-step, wherein the temperature of the water phase and the mixture obtained in Step 1) each independently is above 60℃, preferably above 65℃, for example above 70℃, 75℃, or 80℃; and
3) homogenizing the mixture obtained in Step 2) .
The water in oil emulsion prepared by the method above is stable.
In Step 2) , the water phase is added directly to the mixture obtained in Step 1) in one-step, alternatively, the mixture obtained in Step 1) is added directly to the water phase in one-step.
The mixture obtained in Step 1) may be called as “oil phase with emulsifiers” .
Preferably, Step 1) is carried out at 70-120℃, more preferably at 80-110℃.
Preferably, Step 2) is carried out at 70-100℃, more preferably at 80-90℃.
Preferably, Step 3) is carried out at 70-100℃, more preferably at 80-90℃.
Preferably, Step 3) is carried out at a stirring speed of 1000-30000 rpm, more preferably at a stirring speed of 1500-20000 rpm. The stirring speed is based on the homogenizing facilities used. It should be mentioned that the stirring speed should also depend on the spindle type. Although the emulsion could be prepared with gentle stirring, with higher temperature and stronger stirring process, the emulsion time could be shortened.
According to another aspect of the present invention, there is provided a stable water in oil emulsion prepared according to the process to prepare a stable water in oil emulsion of the invention.
According to another aspect of the present invention, there is provided a cosmetics, dermatological, household, industrial or pharmaceutical product, which comprises the stable water in oil emulsion of the invention, and a container. The container may be for example, a bottle containing the emulsion of the invention.
In the water in oil emulsion of the present invention, other components generally used in cosmetics, pharmaceuticals, and so on can be arbitrarily incorporated, as necessary, within the range that the effect of the present invention is not undermined.
Examples thereof include moisturizers, water-soluble polymers, thickeners, coating agents, metal ion sequestering agents, lower alcohols, polyhydric alcohols, pH adjusters, antioxidants, antioxidant aids, and perfumes.
The use application of the water in oil emulsion of the present invention is not limited. In particular the water in oil emulsion can be applied in cosmetic products such as pre-makeup, foundation, cheek color, eye shadow, eye liner, and body-care cosmetics.
Other advantages of the present invention would be apparent for a person skilled in the art upon reading the specification.

Detailed description of the invention

The invention is now described in detail by the following examples. The scope of the invention should not be limited to the embodiments of the examples.
Unless otherwise specified, in the examples of the description, stability test was performed according to the criteria below.
Stability test includes: 1) storage at 45℃ for at least 1 months; 2) storage at 25℃ for at least 3 month; and 3) freeze/thaw cycle: -15℃/RT (room temperature, between 20-25℃) for 3 cycles with a 24h interval between two cycles.
“Passed” means the emulsion passed stability test above and the emulsion was stable (i.e., no breaking, no separation by visual inspection) . “Failed” means breaking or separation happened at one or more of the 3 kinds of stability test conditions.
Example 1
A W/O emulsion was prepared according to the formulation below.
Preparation of W/O emulsifier composition:
8g Cetyl PEG/PPG-10/1 dimethicone and 0.2g Glyceryl Stearate; PEG-100 Stearate were mixed together in a beaker, 2g Magnesium Stearate was added into the mixture. The beaker with all ingredients was put on a 100℃ hot-board and stirred, then the mixture was homogenized under 10000 rpm for 5min to obtain a one-step W/O emulsifier composition.
Preparation of W/O emulsion:
2.55g one-step W/O emulsifier composition was added into a beaker, 25g white oil was added. The mixture was heated to 80℃ and stirred to homogenate to prepare an oil phase. 1g Sodium Chloride and 2g Glycerin was added to 69.45g water and heated to 80℃ to make a water phase. Unlike the standard way of adding water phase into oil phase gradually while stirring, the water phase was added into the oil phase directly in one-step, then a 4 bladed spindle was used to homogenize the emulsion at 3000rpm for 5 minutes. Then the stirring speed was slowed down to 500rpm, and the emulsion was cooled down to 35℃. 0.05g Phenoxyethanol and Ethylhexylglycerin ( PE 9010, a cosmetic preservative commercially available from Schuelke &Mayr) , was added into the emulsion, and the emulsion was stirred for another 5 minutes.
The prepared emulsion passed the stability test and was stable.
Comparative Example 1
The formulation of Comparative Example 1 was as follows,
In Comparative Example 1, the preparation of emulsion was the same as that of Example 1, except that Cetyl PEG/PPG-10/1 Dimethicone was used instead of the one-step emulsifier composition of Example 1. A W/O emulsion could be prepared in one-step, but the emulsion was not stable, it could not pass the freeze/thaw cycle tests, and had separation within 1 week at 45℃.
Example 2
A W/O emulsion was prepared according to the formulation below.
The preparation method of the emulsifier composition and emulsion was the same as that in Example 1, except that Glyceryl Stearate; PEG-100 Stearate in Example 1 was replaced by Polyglyceryl-3 Dicitrate/Stearate in this example.
The prepared emulsion passed the stability test and was stable.
Example 3
A W/O emulsion was prepared according to the formulation below.
18g Cetyl PEG/PPG-10/1 Dimethicone and 2gCare LTP were mixed together to prepare a liquid-phase emulsifier. 2.5g emulsifier and 0.5g Magnesium Stearate were added into a beaker, then 12.5g C12-15 Alkyl Benzoate and Caprylic/Capric Triglyceride were further added into the beaker and mixed together. The resulting mixture was heated to 80℃ to prepare an oil phase with emulsifiers. 1g Sodium Chloride and 2g Glycerin was added to 68.3g water and heated to 80℃ to make a water phase. The water phase was added into the oil phase directly in one-step, then a 4 bladed spindle was used to homogenize the emulsion at 3000rpm for 5 minutes. Then the stirring speed was slowed down to 500rpm, and the emulsion was cooled down to 35℃. 0.7g Phenoxyethanol and Ethylhexylglycerin was added into the emulsion, and the emulsion was stirred for another 5 minutes.
The prepared emulsion passed the stability test and was stable.
Example 4
A W/O emulsion was prepared according to the formulation below.
The preparation method of the emulsifier composition and the emulsion of this example was the same as that in Example 1, except that Glyceryl Stearate; PEG-100 Stearate in Example 1 was replaced byCare LTP, and Magnesium Stearate in Example 1 was replaced by wax and silica. R 805 is a hydrophobic silica commercially available from Evonik Industries AG.
The prepared emulsion passed the stability test and was stable.
Example 5
A W/O emulsion was prepared according to the formulation below.
9g Cetyl PEG/PPG-10/1 Dimethicone, 3g Sorbitan Laurate and 0.25g Care LTP were mixed together to prepare a liquid-phase emulsifier composition. The preparation of the emulsion was the same as that in Example 3, except that in this example the oil phase was directly added to the water phase in one-step, then a T25 Digital homogenizer (with the dispersing tool S 25 N-18G, commercially available from IKA) (instead of a 4 bladed spindle in Example 3) was used to offer the homogenization process with 20000 rpm, 3min.
The prepared emulsion passed the stability test and was stable.
Comparative Example 2
The formulation of Comparative Example 2 was as follows,
In Comparative Example 2, the preparation of emulsion was the same as that of Example 5, except that the Cetyl PEG/PPG-10/1 Dimethicone, Sorbitan Laurate, Care LTP and Magnesium Stearate in Example 5 was replaced by Cetyl PEG/PPG-10/1 Dimethicone in this example. Oil phase was directly added into water phase in one-step, then a T25 Digitalhomogenizer was used to offer the homogenization process with 20000 rpm, 3min. However, a W/O emulsion could not be successfully prepared.
Example 6
Two W/O emulsions were prepared according to the formulations below.
The preparation method of the emulsifier composition and the emulsion in Example 6a was the same as that in Example 3, except thatCare LTP in Example 3 was replaced by Sorbitan Laurate in this example. The preparation method of the emulsifier composition and the emulsion in Example 6b was as following: 9g Cetyl PEG/PPG-10/1 Dimethicone, 3g Sorbitan Laurate and 0.25gCare LTP were mixed together to prepare a liquid-phase emulsifier composition. 1.5g emulsifier composition, 0.5g Hydrogenated Castor Oil and 0.5g Microcrystalline were added into a beaker, then 8g Caprylic/Capric Triglyceride, 8g Diethylhexyl Carbonate and 8g Ethylhexyl Palmitate were further added into the beaker and mixed together. The resulting mixture was heated to 80℃ to prepare an oil phase with emulsifiers. 3g Sodium Chloride and 3g Glycerin was added to 66.8g water and heated to 80℃ to make a water phase. The water phase was added into the oil phase directly in one-step, then a T25 Digitalhomogenizer (with the dispersing tool S 25 N-18G, commercially available from IKA) was used to offer the homogenization process with 20000 rpm, 3min.
Both emulsions passed the stability test and were stable.
Example 7
A W/O emulsion was prepared according to the formulation below.
9g Cetyl PEG/PPG-10/1 Dimethicone, 3g Sorbitan Laurate and 0.25g Care LTP were mixed together to prepare a liquid emulsifier composition. 2.5g emulsifier composition, 0.5g Magnesium Stearate and other ingredients of Phase A were mixed together at 80℃. Phase B was dispersed with a T25 Digitalhomogenizer (13800rpm) for 5min and added to Phase A, stirring and keeping the temperature at 80℃. Phase C was mixed and heated to 80℃. Unlike the traditional way of adding Phase C slowly while stirring which takes a long period of time, Phase C was added directly into Phase A+B in one-step, and then the resulting mixture was homogenized at 20000 rpm with a T25 Digitalhomogenizer for 90s. Then the mixture was cooled down to 40℃ while stirring and Phase D was added. The whole mixture was stirred slowly to prepare a homogenized emulsion.
The prepared emulsion passed the stability test and was stable at room temperature and 45℃ for 3 months and passed the freeze/thaw stability test.
Example 8
A W/O emulsion was prepared according to the formulation below.
The preparation method of the emulsifier composition and emulsion in Example 8 was as following: 9g Cetyl PEG/PPG-10/1 Dimethicone, 3g Sorbitan Laurate and 0.25gCare LTP were mixed together to prepare a liquid emulsifier composition. 2.5g emulsifier composition, 0.5g Magnesium Stearate and other ingredients of Phase A were mixed together at 80 . Phase B was mixed and heated to 80 . Unlike the traditional way of adding Phase B slowly while stirring, Phase B was added directly into Phase A in one-step, and then the resulting mixture was homogenized at 20000 rpm with a T25 Digitalhomogenizer for 90s. Then the mixture was cooled down to 40℃ while stirring and Phase C was added. The whole mixture was stirred slowly to prepare a homogenized emulsion.
The prepared emulsion was stable at room temperature and 45℃ for 3 months and passed the freeze/thaw stability test.
Example 9
A W/O emulsion was prepared according to the formulation below.
The preparation of emulsifier and emulsion was the same as that in Example 1, except that Glyceryl Stearate; PEG-100 Stearate in Example 1 was replaced by Glyceryl Stearate, and White Oil in Example 1 was replaced by C12-15 Alkyl Benzoate and Caprylic/Capric Triglyceride.
The prepared emulsion passed the stability test and was stable.
As used herein, terms such as "comprise (s) " and the like as used herein are open terms meaning 'including at least' unless otherwise specifically noted.
All references, tests, standards, documents, publications, etc. mentioned herein are incorporated herein by reference. Where a numerical limit or range is stated, the endpoints are included. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out.
The above description is presented to enable a person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, certain embodiments within the invention may not show every benefit of the invention, considered broadly.

Claims

An emulsifier composition, comprising:

(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12, for example 2-12, preferably from 2-9;

(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyether polyol or polyol with a C1-C22 fatty acid, and has an HLB value from 4 to 13; and optionally

(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms; and optionally

(C) A particle selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms.
The emulsifier composition of claim 1, wherein the emulsifier composition comprises the primary emulsifier and the co-emulsifier only, or comprise the primary emulsifier, the co-emulsifier and the additional emulsifier ingredient only, or the primary emulsifier, the co-emulsifier and the particle only, or comprise the primary emulsifier, the co-emulsifier, the additional emulsifier ingredient and the particle only.
The emulsifier composition of claim 1, wherein the polyether polyol or polyol is selected from sorbic alcohol, sorbitan, mono-or poly-glycerol, polyethylene glycol and poly (propylene glycol) .
The emulsifier composition of claim 1, wherein the additional emulsifier ingredient is selected from citric acid partial esters carrying neutralizable acid functions or citric acid partial esters carrying acid functions, at least partially neutralized, of aliphatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols with a chain length of from 6 to 22 carbon atoms.
The emulsifier composition of claim 1, wherein the silica particles are selected from hydrophobic silicas, especially with a mean particle size of 10 nm to 6500 nm.
The emulsifier composition of claim 1, wherein the primary emulsifier constitutes 30-90wt-%, preferably 40-80wt-%, for example 50-80wt-%, 55-80wt-%, the co-emulsifier constitutes 1-45wt-%, for example 1.5-40wt-%, 1.5-35wt-%, 1.5-30wt-%, preferably 2-35wt-%, the particle constitutes 0-45wt-%, for example 0-40wt-%, 0-35wt-%, 0-30wt-%, 0-25wt-%, 0-20wt-%, 5-45wt-%, 5-40wt-%, 5-35wt-%, 5-30wt-%, 5-25wt-%, 5-20wt-%, preferably 10-40wt-%, for example 10-30wt-%, 10-25wt-%, 10-20wt-%, based on the total weight of the emulsifier composition; and preferably, the additional emulsifier ingredient constitutes 1 to 20 wt-%, for example 3 to 10 wt-%of the weight of the co-emulsifier.
An emulsifier composition, which is comprised of, or is essentially comprised of:

(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12, for example 2-12, preferably from 2-9;

(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyether polyol or polyol with a C1-C22 fatty acid, and has an HLB value from 4 to 13; and optionally

(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms; and optionally

(C) A particle selected from silica particles and metal salts of a fatty acid with 8-22 carbon atoms.
An emulsifier composition, which is comprised of, or is essentially comprised of:

(A) A primary emulsifier selected from alkyl and polyether modified polysiloxane emulsifiers, wherein the emulsifier has an HLB value of less than 12, for example 2-12, preferably from 2-9; and

(B) A co-emulsifier, wherein the co-emulsifier is an ester formed by a polyol with 3-6 carbon atoms and 3-6 hydroxyl groups and a C12-C18 fatty acid, and has an HLB value from 4 to 13; and optionally

(B’) An additional emulsifier ingredient selected from di-or polycarboxylates optionally containing hydroxyl groups, sulfated or sulfonated or phosphate carboxylates, malonates, malates, succinates, sulfosuccinates, citrates, tartrates in which the acid groups have been partially esterified with aliphatic or aromatic, linear or branched, optionally unsaturated and/or hydroxyl-functionalized alcohols or polyols with a chain length of from 6 to 22 carbon atoms.
Use of the emulsifier composition according to any one of claims 1-8 in preparation of a stable water in oil emulsion in one-step.
A process to prepare a stable water in oil emulsion, comprising:

1) mixing the emulsifier composition or ingredients of the emulsifier composition according to any one of claims 1-8 with at least one oil phase component to obtain a mixture with emulsifiers;

2) mixing a water phase directly with the mixture obtained in Step 1) ; wherein the temperature of the water phase and the mixture obtained in Step 1) each independently is above 60℃, preferably above 65℃, for example above 70℃, 75℃, or 80℃; and

3) homogenizing the mixture obtained in Step 2) .
A stable water in oil emulsion prepared according to the process according to claim 10.
A stable water in oil emulsion, which comprises:

(1) an oil phase;

(2) a water phase; and

(3) the emulsifier composition according to any one of claims 1-8.
A cosmetics, dermatological, household, industrial or pharmaceutical product which comprises the stable water in oil emulsion according to claim 11 or 12 and a container.