| 摘要 |
An oil-in-water emulsion containing 0.5% to 30% metallic oxides having a particle size of less than 0.2 micron, less than 10% total emulsifier, 5% to 30% of an oil phase and at least 60% of an aqueous phase is provided. The invention also makes available a method of preparing such emulsions in which the emulsion is formed by use of a dispersion in water of the metallic oxide particles. By comparison with previously known emulsions of this type relatively small quantities of emulsifiers are used and it is possible to use an emulsion system with a low HLB value (e.g. less than 6). Preferably no hydrophilic emulsifiers are used. The emulsions are suitable for preparing UV-absorbing compositions such as sunscreens, moisturisers and after-sun lotions. The ability to use no, or little, hydrophilic emulsifiers is advantageous since, in, general, these emulsifiers are not biodegradable whereas hydrophobic emulsifiers generally are biodegradable.
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