Emulsifier-free finely disperse systems of the oil-in-water and water-in-oil type
AssigneeBeiersdorf AG
InventorsHeinrich Gers-Barlag, Anja Muller
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Abstract
Pickering emulsions, which are finely disperse systems of the water-in-oil or oil-in-water type, comprising (1) an oil phase which contains a wax and/or an oil thickener, (2) a water phase, (3) at least one type of microfine particles which a) have an average particle size of less than 200 nm, which b) display both hydrophilic and lipophilic properties, i.e. which have amphiphilic character, and are dispersible both in water and in oil and which c) have optionally been coated on the surface, (4) at least one type of non-amphiphilic metal oxide pigments and (5) at most 0.5% by weight of one or more emulsifiers.
Claims11
Pickering emulsions, which are finely disperse systems of the water-in-oil or oil-in-water type, comprising
- (1) an oil phase,
- (2) a water phase,
- (3) at least one type of microfine particles which
- a) have an average particle size of less than 200 nm, which
- b) display both hydrophilic and lipophilic properties, i.e. which have amphiphilic character, and are dispersible both in water and in oil and which
- c) have optionally been coated on the surface,
- (4) at least one type of non-amphiphilic metal oxide pigments and
- (5) at most 0.5% by weight of one or more emulsifiers.
Pickering emulsions according to one of the preceding claims, characterized in that the content of the amphiphilic particles is between 0.1% by weight and 30% by weight, based on the total weight of the preparations.
Pickering emulsions according to one of the preceding claims, characterized in that the particle diameter of the amphiphilic particles is between 5 nm and 100 nm.
Pickering emulsions according to one of the preceding claims, characterized in that the amphiphilic particles are chosen from the group consisting of amphiphilic metal oxides, boron nitride, microfine polymer particles and modified polysaccharides, it being possible for the particles to be present individually or as a mixture.
Pickering emulsions according to one of the preceding claims, characterized in that the amphiphilic particles have been surface-treated to repel water, where the amphiphilic character of the particles is formed or retained.
Pickering emulsions according to one of the preceding claims, characterized in that the total amount of non-amphiphilic pigments in the finished cosmetic or dermatological preparations is chosen to be less than 20% by weight, preferably between 0.5 and 10% by weight, based on the total weight of the preparations.
Pickering emulsions according to one of the preceding claims, characterized in that the non-amphiphilic pigment(s) is/are chosen from the group consisting of the hydrophobic or hydrophobically coated metal oxides, in particular from the group consisting of the hydrophobic or hydrophobically coated titanium dioxides.
Pickering emulsions according to one of the preceding claims, characterized in that the non-amphiphilic pigment(s) is/are selected from the group consisting of the hydrophilic or hydrophilically coated metal oxides, in particular from the group consisting of the hydrophilic or hydrophilically coated titanium dioxides.
Sunscreen preparations based on Pickering emulsions according to one of the preceding claims.
Use of at least one type of non-amphiphilic metal oxide pigments for increasing the UV protection performance of cosmetic or dermatological Pickering emulsions.
Dependencies are inferred from the claim text.