CH625414A5 - - Google Patents

Description

The present invention relates to new fluid emulsions of the water in oil type, which can be used in particular for producing cosmetic compositions.

It is advantageous to produce cosmetic products which are in the form of emulsions of the water in oil type, because the water retained in the dispersed state in the oily phase ensures good hydration of the epidermis, while the lipid film, which tends to limit water loss from the epidermis, prevents drying of the skin.

However, it has so far been difficult to market cosmetic products of this type, since water-in-oil emulsions have always presented two kinds of difficulties.

On the one hand, it is necessary that these emulsions do not give rise to the inversion phenomenon, that is to say to the phenomenon of transformation into an emulsion of the oil in water type.

On the other hand, it is necessary that the cosmetic products in the form of emulsions are sufficiently stable to retain their finely dispersed structure, despite the storage times which can be very long and despite significant temperature variations which, in general , promote the destruction of the emulsion by loss of the dispersed state of the aqueous phase. This risk is particularly important in the case where the emulsions are subjected to low temperatures.

In the stability of emulsions, the nature of the emulsifier is very important.

Among the various products which have been proposed as emulsifiers, mention may in particular be made of block polymers resulting from the condensation of ethylene oxide on polypropylene glycols. These polymers can be represented by the following formula:

HO— (CH2CH20) a (CHCH20) b (CH2CH20) a-H

ch3

in which a and b represent whole numbers.

Among the emulsifiers of this type, there may be mentioned in particular the Emkalyx-Pluronics marketed by the Société des Produits Chimiques Ugine-Kulhmann or by Wyandotte Chemicals Corporation.

Block polymers of this type have been used heretofore to promote the stability of oil in water, and not water in oil emulsions. On the contrary, these polymers have even been recommended as demulsifiers which, by considerably lowering the surface tension, are capable of breaking water-in-oil emulsions.

It has now been discovered that it is possible to use certain block polymers of the type indicated above to produce stable water-in-oil emulsions.

The present invention relates to new emulsions comprising an aqueous phase, an oily phase, and as an emulsifier a block polymer resulting from the condensation of ethylene oxide on propylene glycols, characterized in that they contain from 30 to 60 % of water, that they are produced with an oil whose dielectric constant is greater than 3.70, that said block polymer has a hydrophyl / lipophilic balance less than 3.5 and that said emulsions constitute emulsions of the water type in oil.

In preferred embodiments, the new emulsions of the invention may also have the characteristics indicated below, taken individually or in combination.

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625414

A block polymer resulting from the condensation of ethylene oxide on polypropylene glycols is preferably used as the emulsifying agent, said block polymers having an average molecular weight which can vary from 3000 to 5000, the oxyethylene content can vary from 5 to 20%. , and the HLB value being less than 3.5 and preferably less than 3. In particular, an emulsifier having a molecular mass of approximately 4000, an oxyethylene content of approximately 10% and an HLB value of 0.5 is used about. For example, the emulsifier consists of the block polymer marketed under the name Pluronic L 121 by the Company of Chemicals Ugine-Kuhlmann. Mention will also be made of a polymer having a molecular mass of approximately 3600, an oxyethylene content of approximately 10% and an HLB value of approximately 1, such as Pluronic L 101, or a polymer having a molecular mass of approximately 2500, a oxyethylene content of approximately 10% and an HLB value of 2, such as Pluronic L 81.

The emulsions of the invention may also contain one or more secondary emulsifiers, in a proportion of 0 to 10% by weight relative to the total weight of the emulsion. As secondary emulsifiers, lecithin and lanolin can be used, for example.

The oil used to carry out the oily phase may be either a single product or a mixture of oils, some of which may have a dielectric constant of less than 3.70, provided that the polarity of the mixture is greater than or equal to 3.70 .

In the emulsions of the invention, the oil content can vary from 20 to 60% by weight.

As indicated above, the emulsifier is present, in the emulsions of the invention, in a sufficient amount, that is to say in an amount making it possible to ensure the stability of the emulsion for a sufficient time, for example for at least two months at room temperature. Preferably, the emulsifiers are used in a proportion which can vary from 4 to 35% by weight relative to the total weight of the emulsion.

Among the oils which can be used, there may be mentioned in particular those which have a dielectric constant greater than 3.70 and which correspond to one of the following definitions:

a) The glycerol derivatives of formula I:

HO-CH ^ 0

H2-X-R, "CH2-Y-R2

(I)

in which:

X and Y, identical or different, represent either - O - 0-Ç-:

is

Ri represents a branched alkyl radical having 5 to 8 carbon atoms, the number of branched carbon being 1, 2 or 3, and

R2 represents a linear alkyl radical having 11 to 18 carbon atoms.

These derivatives are described in French patent application No 74.09657 filed on March 21, 1974 in the name of the owner.

Among these derivatives, mention will be made in particular of those mentioned in the following table which gives their dielectric constant. ■

b) The derivatives of alkanediol-1,2 as well as their mixtures of general formula II:

R

r

CH-

X-R 'OH

(II)

in which:

X represents either an oxygen atom or an io carbonyloxy group — Ç — O— linked to the group R ′ via the free bond of the carbon atom of the carbonyloxy group,

R 'represents a saturated alkyl radical having 5 to 21 carbon atoms, or alternatively, in the case where X represents - COO—, R'

represents a hydrocarbon residue of lanolic acid, one of the substituents R! and R2 represents a linear alkyl radical having 8 to 16 carbon atoms and the other represents a hydrogen atom.

These derivatives are described in French patent application 2 ° N ° 75.24656 filed on August 7, 1975 in the name of the owner.

In the following table, the dielectric constants of the derivatives described in this French patent application are given.

Request example number

/

No 75.24656

5

4.36

7

4.47

8

4.46

c) The substituted glycerol derivatives of formula III: R-X-CH, -ÇH- (j: H2

L

(III)

In which one of the substituents Zj or Z2 represents a group —YR 'and the other represents a hydroxyl group, R and R' represent saturated and branched hydrocarbon radicals derived from alcohols R — OH or R'— OH or of R — C02H or R'— C02H acids, said alcohols or acids containing from 6 to 20 carbon atoms, and X and Y, identical or different, represent either an oxygen atom or a group -S- ° - connected to the group-

O

ment R or R 'via the free bond of the carbonyl carbonyloxy atom.

These substituted derivatives are described in French patent application No. 75.24658 filed on August 7, 1975 by the owner. The dielectric constants of derivatives described in this French patent application are given in the following table.

Sample application no. 74.09657

e

5

4.3

7

5.15

11

5.03

8

4.40

4

4.75

6

4.1

9

4.76

Sample application no. 75.24658

s'

3

4.44

4

4.59

5

5.16

6

5.00

7

5.83

8

4.58

d) The compounds of general formula IV:

(IV)

65 in which:

R represents an alkyl radical or a mixture of alkyl radicals having from 7 to 20 carbon atoms, a hydrocarbon residue of lanolin alcohol when X = 0, or a hydrocarbon residue of acid

625414

4

lanolic when X = - (j? —O—; one of the substituents Zj or Z2 O

represents the group - CH2 — Y - R ', the other represents a hydrogen atom; X represents an oxygen atom or a carbonyloxy group —C — O— linked to the group R via the free bond of the carbon atom of the carbonyloxy group; Y represents a group - CH2 -, an oxygen atom or a carbonyloxy group —Ç — O—

linked to the group R 'via the free bond of the carbon atom of the carbonyloxy group; R 'represents an alkyl radical or a mixture of alkyl radicals having from 3 to 20 carbon atoms and a part of the groups - Y — R' can represent a radical —O — H; A is a hydrogen atom and A can also represent the group R'— Ç— in the case where Y

represents a carbonyloxy group, and n is an integer or decimal number greater than 1 less than or equal to 10.

These compounds are described in French patent application No. 75.24657 filed on August 7, 1975 in the name of the owner.

The dielectric constants of some of these compounds are given in the following table.

No. "in the example of application No. 75.24657

e '

9

4.24

11

4.23

15

4.32

16

5.86

17

5.68

18

4.27

19

4.49

e) Mixtures of triglycerides of saturated C8 / C12 fatty acids such as that marketed under the name Miglyol 812 by the company Dynamit Nobel, whose dielectric constant is 3.79.

0 Castor oil with a dielectric constant of 4.49.

g) Lemonellol diadipate with a dielectric constant of 4.02.

h) Short-chain fatty acid polyol diesters such as the oil extracted from coconut oil sold under the name Neobee X1054 by the company P.V.O. Int., Whose dielectric constant is 3.79.

i) Polyoxypropylenated fatty acid ethers such as that sold under the name Arlamol E by the company Atlas I.C.I., the dielectric constant of which is 4.73.

In the general formulas I to IV of the products of the various French patent applications cited, the designation of the substituents has not been modified in order to respect that which appears in these patent applications. It is understood that the definition of a given substituent is only valid by reference to a determined general formula.

As indicated above, it is possible to use, in admixture with oils whose dielectric constant is greater than 3.70, other oils whose dielectric constant is less than 3.70, provided that the dielectric constant of the mixture is greater than this value.

Among these oils which can be used in mixture with oils whose dielectric constant is greater than 3.70, there may be mentioned in particular 2-ethylhexyl acetoxystearate sold by the company Dubois, under the name Eriol, isopropyl palmitate ,

etc.

To increase the stability of the emulsions according to the invention, it is also possible to introduce from 0 to 3.5% by weight of a crosslinking agent such as ozokerite.

The emulsions according to the invention make it possible to produce fluid cosmetic products used for the toilet or for skin care. These cosmetic compositions constitute, for example, make-up removal milks, body milks, sunscreen milks, etc.

These cosmetic compositions may contain, in addition to the constituents of the emulsion mentioned above, various constituents usually used in this type of composition, for example coloring agents, perfumes, preservatives, com-io poses absorbing the ultraviolet , etc.

To prepare the emulsions according to the invention, the usual methods for preparing water-in-oil emulsions are used.

One can, for example, use the following method; the oily phase and the emulsifier are introduced into the manufacturing tank, the mixture is heated to a temperature of 70 to 75 ° C., the aqueous phase is added while stirring, continuing to stir until an emulsion having the desired fineness, then allowed to cool to room temperature, possibly with slow stirring.

When the emulsion contains ozokerite, the latter is dissolved beforehand hot (80-85 ° C.) in the oily phase,

then allowed to cool to 70-75 C before adding the aqueous phase.

Most often, it is advantageous to directly prepare cosmetic compositions in the form of water-in-oil emulsions. For this, it is possible, for example, to mix the ingredients soluble in oil with the oily phase before the addition of the aqueous phase which will consist of water containing in solution the water-soluble ingredients of the composition.

Generally, the oil or the mixture of oils is introduced into the manufacturing tank, as well as the emulsifier. It is heated to a temperature of 70 to 75 ° C. The oil-soluble ingredients are then added, followed by addition, with stirring, of the water, in which the water-soluble ingredients, if present, have previously been dissolved (for example, preservatives), the mixture is stirred until an emulsion having the desired fineness, then allowed to cool to room temperature, optionally with slow stirring.

The following examples illustrate the invention without, however, limiting it.

In these examples, the compound of .40 has been designated by compound X:

C4Hg —CH — CH2 — O — CH — CH2 — O —CO —Ci5H3I C2H5 OH

4J Example 1

A milk corresponding to the following formula was prepared:

Pluronic L 121 (Ugine-Kulhmann) 6,000 kg

Compound X 44,000 kg

Merthiolate (preservative) 0.003 kg

50 Perfume q.s.

Sterile demineralized water q.s.p 100,000 kg

Procedure

- In the manufacturing tank, introduce the Pluronic and the compound 55 X. Bring the temperature to 70/75 ° C and maintain a slow agitation for 2 h.

- Start the agitator and introduce the aqueous phase (that is to say the preservative which has probably been dissolved in water).

60 - After 20 minutes, stop stirring and cool gently to 30 C.

- Restart the agitator and introduce the perfume.

- Leave to stir until the fineness of the emulsion conforms to the desired type (approximately 20 minutes).

65 - Then slowly stir to 25 C, then stop.

By operating in a similar manner, a milk corresponding to

the following formula: ..... .

( See next page)

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625414

Pluronic L 121 6,000 kg

Lemonellol adipate 44,000 kg

Preservative (merthiolate) 0.003 kg

Perfume q.s.

Sterile demineralized water q.s.p 100,000 kg 5

at)

Part A

Example 2

Part A

Pluronic L 121 (Ugine-Kulhmann)

Lecithin powder

Compound X

Eriol (Dubois)

Refined white ozokerite .... Preservative (merthiolate). Sterile demineralized water q.s.p. . Perfume q.s.

6,000 kg 1,000 kg 35,000 kg 5,000 kg 3,000 kg 0.003 kg 100,000 kg

Procedure

- In the manufacturing tank, introduce the elements of part A and bring the temperature to 60 ° C.

- Maintain slow agitation until complete disappearance of the lecithin (approximately 4 h).

- Then introduce the refined white ozokerite and bring the temperature to 80/85 ° C while maintaining agitation.

- After complete dissolution of the refined white ozokerite, lower the temperature to 70/75 ° C.

- Start the agitator and introduce the aqueous phase at 70/75 ° C (i.e. water and the preservative which has been previously dissolved).

- After 20 minutes, stop stirring and cool gently to 30 ° C.

- Restart the agitator and introduce the perfume.

- Leave to stir until the fineness of the emulsion conforms to the desired type (approximately 20 minutes).

- Then put under slow stirring up to 25 ° C, then stop.

By operating in a similar manner, the following formulas have been prepared:

20

b)

Part A

vs)

Part A

d)

Part A

e)

Part A

Pluronic L 121 6,000 kg

Lecithin powder 1,000 kg

Eriol (Dubois) 5,000 kg

Arlamol E (I.C.I.) 35,000 kg

Refined white ozokerite 3,000 kg

Preservative (merthiolate) .... 0.003 kg Perfume q.s.

Sterile demineralized water q.s.p 100,000 kg

Pluronic L 121 6,000 kg

Lecithin powder 1,000 kg

Castor oil 40,000 kg

Refined white ozokerite 3,000 kg

Preservative (merthiolate) .... 0.003 kg Perfume q.s.

Sterile demineralized water q.s.p 100,000 kg

Pluronic L 121 6,000 kg

Lecithin powder 1,000 kg

Neobee X 1054 (PVO) 40,000 kg

Refined white ozokerite 3,000 kg

Preservative (merthiolate) .... 0.003 kg Perfume q.s.

Sterile demineralized water q.s.p 100,000 kg

Pluronic L 101 7,000 kg

Eriol (Dubois). 5,000 kg

Arlamol E (I.C.I.) 35,000 kg

Refined white ozokerite 3,000 kg

Perfume and preservative, q.s.

Water q.s.p 100,000 kg f Pluronic L 81 7,000 kg

1 Compound X 40,000 kg

Refined white ozokerite 3,000 kg

Perfume and preservative, q.s.

Water q.s.p 100,000 kg

R

Claims (18)

625414 1. Emulsion comprising an aqueous phase, an oily phase and at least one emulsifier comprising a block polymer resulting from the condensation of ethylene oxide on prolylene glycols, characterized in that it contains from 30 to 60% d water, that it is produced with an oil whose dielectric constant is greater than 3.70, that said block polymer has a hydrophilic / lipophilic balance less than 3.5 and that said emulsion constitutes a water-in-oil emulsion. 2. Emulsion according to Claim 1, characterized in that the said block polymer has an average molecular mass which can vary from 3000 to 5000, the oxyethylene content being able to vary from 5 to 20%. 2 3. Emulsion according to one of the preceding claims, characterized in that the said block polymer has a molecular mass of approximately 4000, an oxyethylene content of approximately 10% and an HLB value of approximately 0.5. 4. Emulsion according to any one of claims 1 or 2, characterized in that the said block polymer has a molecular mass of approximately 3600, an oxyethylene content of approximately 10% and an HLB value of approximately 1. 5. Emulsion according to one of claims 1 or 2, characterized in that the said block polymer has a molecular mass of approximately 2500, an oxyethylene content of approximately 10%, and an HLB value of 2. 6. Emulsion according to one of the preceding claims, characterized in that the oil content can vary from 20 to 60% by weight. 7. Emulsion according to one of the preceding claims, characterized in that the emulsifying agent or the mixture of emulsifying agents is present in an amount sufficient to ensure sufficient stability of the emulsion. 8. Emulsion according to one of the preceding claims, characterized in that the emulsifying agent or the mixture of emulsifying agents is present in an amount sufficient to ensure stability of the emulsion for at least two months at room temperature. 9. Emulsion according to one of the preceding claims, characterized in that the emulsifying agent or the mixture of emulsifying agents is present in an amount of 4 to 35% by weight relative to the total weight. 10. Emulsion according to one of the preceding claims, characterized in that it also contains a secondary emulsifier in a proportion which can vary from 0 to 10% relative to the total weight. 11. Emulsion according to Claim 10, characterized in that the said secondary emulsifier is chosen from the group consisting of lecithin and a lanolin. 12. Emulsion according to one of the preceding claims, characterized in that it also contains from 0 to 3.5% by weight of a crosslinker. 13. Emulsion according to claim 12, characterized in that the crosslinker is ozokerite. 14. Emulsion according to one of the preceding claims, characterized in that the said oil is a mixture of oils, the dielectric constant of the mixture being greater than 3.70. 15. Emulsion according to one of the preceding claims, characterized in that the oil is constituted by the compound of formula: C4H9-CH-CH2-0-CH-CH2-0-C0-ClsH3I C2Hs OH 16. Use of the emulsion according to claim 1 in a cosmetic composition. 17. Use according to claim 16, characterized in that the cosmetic composition also contains constituents making it suitable for use as cleansing milk, body milk or sunscreen milk. 18. Use according to claim 17, characterized in that the composition contains at least one of the following constituents: coloring agent, perfume, preservative agent, compound absorbing the ultraviolet.