CH635756A5 - PROCESS FOR THE PREPARATION OF WATER-IN-OIL (W / O) OR OIL-IN-WATER (O / W) TYPE EMULSIONS WITH LOW WATER CONTENT AND CONTAINING POLYETHYLENE POWDER AND EMULSIONS THUS OBTAINED. - Google Patents

Description

The subject of the present invention is a process for preparing emulsions of the water-in-oil or oil-in-water type with a low water content and containing polyethylene powder; this process consists, in a first stage, in dissolving the emulsifying agent in the oil phase consisting of at least one oil or a mixture of at least one oil and at least one wax, at a temperature of about 70-90 ° C and with stirring, then, in a second stage, to add the water phase in a proportion of between 30 and 55% by weight relative to the total weight of the emulsion and finally to add, still with stirring , at a temperature below 40 ° C and preferably between 20 and 25 ° C, the polyethylene powder in the form of essentially spherical particles whose size is between 3 and 60 | x.

According to a first variant of the invention, the water phase brought to a temperature of about 80-85 ° C is added to the oil phase maintained at the same temperature.

According to a second variant of the invention, the water phase brought to a temperature of about 40-60 ° C is added to the oil phase after cooling of the latter to the same temperature.

This second variant is preferably used when oils sensitive to a rise in temperature are used, and it is therefore necessary to cool the oil phase before introducing them.

In this case, the emulsifying agent is in fact dissolved in at least one oil or a mixture of at least one oil and at least one wax, at a temperature of around 70-90 ° C., in particular about 80-90 ° C, then, after cooling, the oils sensitive to a rise in temperature to about 40-60 ° C are added.

According to the invention, the oil phase, that is to say the mixture of at least one oil and at least optionally a wax, varies between approximately 15 and 65% by weight relative to the total weight of the emulsion. .

According to the invention, the water phase of the emulsions is preferably between 30 and 45% relative to the total weight of the emulsion.

The proportion of the emulsifying agent in the emulsions according to the invention is generally between 1 and 20%, and preferably between 2 and 12%.

In accordance with the invention, a large variety of products can be used to constitute the oil phase of the emulsions such as:

- hydrocarbon oils, such as paraffin oil, petroleum jelly, perhydrosqualene, microcrystalline wax solutions in paraffin oil and purcellin oil;

- animal or vegetable oils such as pork fat, sweet almond oil, calophyllum oil, olive oil and avocado oil;

- saturated non-rancidable and well penetrating esters such as isopròpyle palmitate, isopropyl, isooctyl myristate or

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isodecyl, ethyl palmitate, isopropyl adipate and triglycerides of octa- and decanoic acids.

It is also possible to add to the oil phase silicone oils soluble in the other oils, such as dimethylpolysiloxane and methylphenylpolysiloxane.

In certain cases, to promote oil retention, it is possible to use waxes such as carnauba wax, candellila wax, beeswax, microcrystalline wax and ozokerite.

As an adjuvant of the oil phase, long-chain fatty alcohols such as beeswax fatty alcohol, coconut alcohol, myristic alcohol, cetyl alcohol, stearyl alcohol, can also be used. hydroxystearyl alcohol, oleic alcohol and isostearyl alcohol.

It is also possible to add substances such as cholesterol or other sterols of animal or vegetable origin to the oil phase.

Among the various emulsifying agents which can be used in the emulsions according to the invention, there may be mentioned in particular:

- oxyethylenated or polyglycerolated fatty alcohols such as, for example, polyoxyethylene oleic alcohol with 10 mol of ethylene oxide, stearyl alcohol with 10-15 or 20 mol of ethylene oxide, alcohol oleic polyglycerolated with 4 mol of glycerol and synthetic fatty alcohols C9-Cls polyoxyethylenated with 5 or 10 mol of ethylene oxide;

- alkyl sulphates, oxyethylenated or not, such as sodium lauryl sulphate, ammonium lauryl sulphate, sodium cetyl stearyl sulphate, triethanolamine cetyl stearyl sulphate, monoethanolamine lauryl sulphate, oxyethylated sodium lauryl ether sulphate (2,2 of ethylene oxide for example) and the oxyethylenated monoethanomine lauryl ether sulfate (to 2.2 mol of ethylene oxide for example), and the emulsifying agents described in Swiss patent No. 551197 of the applicant company which are mixtures of at least one lanolate such as magnesium, calcium, lithium, zinc and aluminum lanolates, and hydrogenated lanolin and / or lanolin alcohol.

According to the invention, the polyethylene powder used, which must imperatively be introduced after the formation of the emulsions, is in the form of essentially spherical particles whose size is preferably between 20 and 25 | i.

Among the polyethylene powders which correspond to the above definition and which can be used in the emulsions according to the invention, there may be mentioned in particular:

1) Low density type polyethylene powders having a melting temperature of 104-106 ° C (determined according to method ASTM-D 2117-64) and a density at 23 ° C of 0.916-0.918 (g / cm3) (determined according to ASTM-D 2839 method).

Such powders having these characteristics are sold by the company CDF-Chimie under the names of Lotrène UA 7000 S and Lotrène UA 4000 S.

2) High density type polyethylene powders having a softening temperature of 128-129 ° C (determined according to method ASTM-E 28) and a density of 0.96 (g / cm3) (determined according to method ASTM- D 1505).

Such powders having these characteristics are sold by the company Allied Chemical under the names of Polymist B-6 and Polymist B-12.

The polyethylene powders used according to the invention are insoluble in the various oils used for producing the oil phase of the emulsions.

According to a first preferred form of the invention, the polyethylene powder is introduced as indicated above, at a concentration of between 3 and 12% by weight, preferably between 5 and 10% by weight, relative to the weight total emulsion.

According to a second preferred form of the invention, the polyethylene powder is introduced into the emulsion, after the formation of the latter, as a mixture with a conventional filler substance such as titanium oxide, zinc oxide, talc or kaolin.

When the filler is constituted by such a mixture, the concentration of conventional filler is between 1 and 15%, preferably between 3 and 10%, the total concentration of filler (polyethylene + conventional filler) being a function of the cost, the desired mattness and the structure of the formula considered.

In the process for preparing the emulsions according to the invention, it is also possible to introduce various ingredients generally present in the emulsions, in particular dyes (pigments), perfumes, preserving agents such as methyl parahydroxybenzoate or propyl parahydroxybenzoate.

Among the coloring substances capable of being incorporated into the emulsions according to the invention, mention may in particular be made of iron oxides, in particular red iron oxide, yellow iron oxide and black iron oxide.

These coloring substances are preferably introduced into the emulsion after its formation and before the introduction of the polyethylene powder.

However, in certain cases, in order to obtain good dispersion, it may be advantageous to introduce them into the water phase of the emulsions.

The preservative is preferably dissolved, optionally hot, in the aqueous phase of the emulsions.

When a perfume is introduced into the emulsions, it is preferably added to the emulsion at the end of preparation, that is to say after the addition of the polyethylene powder.

If desired, the emulsions obtained by the process according to the invention can be refined by passing them through a mill of the three-cylinder type.

According to the invention, the term oil phase denotes the phase containing at least one oil and the other constituents soluble in oils, and water phase the aqueous solution containing the constituents soluble in water.

Finally, it is important to note that all the steps of the process for preparing the emulsions according to the invention must be carried out with relatively vigorous stirring, in particular as regards the steps of adding pigments and polyethylene powder, so as to obtain good dispersion of dyes and polyethylene powder particles in the bulk of the emulsion.

In order to better understand the invention, we will now describe, by way of illustration and without any limitation, several examples of preparation of water-in-oil (EH) and oil-in-water (HE) emulsions ).

Example 1:

According to the invention, a moisturizer is prepared in the form of an emulsion (E-H) for the face by proceeding as follows.

In an oil phase consisting of a mixture of 44 g of mineral oil and 3 g of beeswax, which is brought to a temperature of approximately 80 ° C., an emulsifying agent formed of 5 is dissolved with stirring. g of magnesium lanolate and 3 g of lanolin alcohol. Then added to this mixture, still with stirring, the water phase consisting of 40 g of water containing 0.1 g of methyl parahydroxybenzoate whose temperature has previously been brought to about 80 ° C.

After cooling to a temperature of about 35 ° C., 10 g of polyethylene powder sold under the trade name Lotrène UA 7000 S are added with stirring to the emulsion thus formed.

An excellent cream is thus obtained with a particularly fine structure, the preservation of which is perfect whatever the usual storage conditions.

Example 2:

A tinted moisturizer is prepared according to the invention in the form of an emulsion (E-H) by proceeding as follows.

To a mixture consisting of:

paraffin oil 31.5g purcellin oil 6g ozokerite 3g

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brought to a temperature of about 80-85 ° C., an emulsifier consisting of 4.25 g of lanolin alcohol and 4.25 g of sorbitan sesquioleate is added with stirring.

After cooling to a temperature of about 40-50 ° C, 3 g of silicone oil (methyphenylpolysiloxane) are added.

To the phase thus prepared, 35 g of water containing 0.1 g of propyl parahydroxybenzoate are then added with stirring, the temperature of which has also been brought to about 40-50 ° C.

After having optionally cooled to a temperature below about 40 ° C., a mixture of pigments having the following composition is added:

red iron oxide 0.70 g yellow iron oxide 0.80 g titanium oxide 1.50 g

Stirring is continued and 10 g of polyethylene powder sold under the trade name of Polymist B-12 are then introduced at a temperature of about 25 ° C.

This cream is particularly soft to the touch and does not give the skin any oily appearance. Its conservation is excellent even at a relatively high temperature.

Example 3:

According to the invention, a blush is prepared in the form of an emulsion (E-H) by proceeding as follows.

An oil phase consisting of the following mixture:

paraffin oil 17 g microcrystalline wax 2 g glycerides of saturated fatty acids 5 g brought to a temperature of about 80 ° C, an emulsifier consisting of 4 g of magnesium lanolate and 3 g of hydrogenated lanolin is added with stirring.

Then added, with stirring, to the phase thus formed a water phase consisting of 54.9 g of water containing 0.3 g of methyl parahydroxybenzoate, the temperature of which has previously been brought to about 80 ° C.

After cooling to a temperature of about 60-65 ° C, a mixture of pigments having the following composition is added:

iron oxide 2.5 g titanium dioxide 1 g

Cooling is continued at a temperature of about 35-40 ° C. and 10 g of polyethylene powder sold under the trade name Lotrène UA 7000 S are added, with stirring.

Example 4:

According to the same procedure as that described in Example 3, a tinted cream was prepared in the form of an emulsion (E-H) from the following ingredients.

Oil phase:

paraffin oil 20 g purcellin oil 4 g perhydrosqualene 6 g ozokerite 2 g

Emulsifying:

magnesium lanolate 5 g lanolin alcohol 3 g

Water phase:

sterile permuted water containing 0.2 g of propyl parahydroxybenzoate 46.4 g Pigments:

yellow iron oxide lg red iron oxide 0.6 g black iron oxide 0.1 g titanium dioxide 1.5 g polyethylene powder:

Lotrene UA 7000 S 10 g

After the addition of the polyethylene powder, 0.4 g of a perfume is introduced with stirring

Example 5:

According to the same procedure as that described in Example 3, a tinted cream was prepared in the form of an emulsion (H-E) by mixing the following ingredients.

Oil phase:

partial fatty acid glycerides 8 g cetyl alcohol 0.5 g oleic acid decylester 8 g vaseline oil 18 g

Emulsifying:

polyglycolic ether of saturated fatty alcohol 4 g

Water phase:

sterile permuted water containing 0.3 g of methyl parahydroxybenzoate 52.9 g of magnesium aluminum silicate 0.7 g Pigments:

yellow iron oxide red iron oxide 2.2 g black iron oxide 20 polyethylene powder:

Polymist B-6 4 g

Example 6:

2J According to the same procedure as that described in Example 3, a blush was prepared in the form of an emulsion (H-E) by mixing the following ingredients.

Oil phase:

isopropyl myristate 10 g

30 isooctyl and isodecyl myristate 10 g Emulsifier:

stearic acid 2.5 g triethanolamine 1 g polyoxyethylene sorbitan monostearate 0.5 g 35 Water phase:

sterile deionized water 46.5 g imidazolidinylurea 0.5 g magnesium aluminum silicate 2 g hydroxyethylcellulose 1.5 g

40 glycerin 5 g Pigments:

titanium dioxide 2 g iron oxide 3 g mica-titanium 5 g 45 polyethylene powder:

Lotrene UA 7000 10 g

Example 7:

According to the same procedure as that described in Example 3, a foundation was prepared in the form of an emulsion (E-H) from the following ingredients.

Oil phase:

isopropyl myristate 20 g paraffin oil 6 g

55 ozokerite 3 g

Emulsifying:

magnesium lanolate 6 g hydrogenated lanolin 5 g

Water phase:

60 sterile deionized water containing 0.2 g of methyl parahydroxybenzoate 42.7 g Pigments:

iron oxide 3 g titanium dioxide 6 g ss polyethylene powder:

Lotrene UA 7000 S 8 g

After the addition of the polyethylene powder, 0.3 g of perfume is added to this emulsion.

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In this example, the pigments were introduced into the emulsion after cooling to a temperature of about 35-40 ° C.

Example 8:

According to the same procedure as that described in Example 3, a moisturizer is prepared in the form of an emulsion (E-H) for the face from the following ingredients.

Oil phase:

mineral oil 44 g beeswax 3 g

Emulsifying:

magnesium lanolate 2.4 g lanolin alcohol 0.6 g

Water phase:

sterile deionized water containing 0.1 g of methyl parahydroxybenzoate 40 g of polyethylene powder:

Lotrene UA 4000 S 10 g

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Claims (15)

635,756 CLAIMS 1. Method for preparing an emulsion of the water-in-oil or oil-in-water type, characterized in that, in a first. stage, the emulsifier is dissolved in the oil phase consisting of at least one oil or of a mixture of at least one oil and at least one wax, at a temperature of 70-90 ° C and with stirring , that, in a second stage, the water phase is added in a proportion of between 30 and 55% by weight relative to the total weight of the emulsion and that finally, after the formation of the emulsion, is added to a temperature below 40 ° C of the polyethylene powder in the form of essentially spherical particles whose size is between 3 and 60 | x. 2. Method according to claim 1, characterized in that the water phase is brought to a temperature of 80-85 ° C and is added to the oil phase maintained at the same temperature. 3. Method according to claim 1, characterized in that the water phase is brought to a temperature of 40-60 ° C and is added to the oil phase maintained at the same temperature. 4. Method according to one of claims 1 to 3, characterized in that the oil phase varies between 15 and 65% by weight relative to the total weight of the emulsion. 5. Method according to one of the preceding claims, characterized in that the water phase is between 30 and 45% by weight. 6. Method according to one of the preceding claims, characterized in that the emulsifying agent is used in a proportion of between 1 and 20% by weight relative to the total weight of the emulsion. 7. Method according to one of the preceding claims, characterized in that the polyethylene powder is added at a temperature between 20 and 25 ° C. 8. Method according to one of the preceding claims, characterized in that the size of the polyethylene particles is between 20 and 25 n. 9. Method according to one of the preceding claims, characterized in that the polyethylene powder is of the low density type whose melting point is 104-106 ° C (ASTM-D 2117-64) and whose density at 23 ° C is 0.916-0.918 (g / cm3) (ASTM-D 2839). 10. Method according to one of claims 1 to 8, characterized in that the polyethylene powder is of the high density type whose softening temperature is 128-129 ° C (ASTM-E 28) and whose density is 0.96 (g / cm3) (ASTM-D 1505). 11. Method according to one of the preceding claims, characterized in that the polyethylene powder is introduced at a concentration of between 3 and 12% by weight relative to the total weight of the emulsion. 12. Method according to one of the preceding claims, characterized in that coloring substances are introduced before adding the polyethylene powder. 13. Method according to one of the preceding claims, characterized in that all the steps are carried out with vigorous stirring. 14. Emulsion with low water content and containing polyethylene powder, characterized in that it is obtained by the process according to one of claims 1 to 13. 15. Emulsion according to claim 14, characterized in that it is in the form of a moisturizing sunscreen or milk, a moisturizer for the face, the body or the hands, a moisturizing blush, eyeshadow or foundation, or in the form of sticks. It is known that water-in-oil or oil-in-water emulsions, in particular water-in-oil emulsions, have the drawback of leaving a more or less significant fatty film on the skin after application. This film is often considered unsightly by users, because it gives the skin a shiny appearance. In order to remedy this defect, it has been recommended to use certain polymers, in particular polyethylene powder, to replace the so-called filler substances used until now. such as titanium oxide, zinc oxide, talc or kaolin. The licensee noted, however, that completely satisfactory results could only be obtained by preparing the water-in-oil or oil-in-water emulsions under very specific conditions. Indeed, by carrying out the preparation of the emulsions under conditions different from those of the invention, it turned out that these did not have all the qualities required to lead to good cosmetic products with regard to the appearance of the skin, that is to say its dullness, and the very softness of the emulsions. Furthermore, it has been found that the emulsions obtained according to the invention had, due to the process used and the low water content of the emulsions, much better stability during storage, regardless of the usual storage conditions. .