Preparation method of physical sun-screening agent for cosmetics

Abstract

The invention discloses a preparation method of a physical sun-screening agent for cosmetics. The preparation method comprises the following steps of weighing a cerium source, adding deionized water and a nonionic surface active agent to the weighed cerium source, and performing heating until the cerium source completely dissolves; adjusting pH to be 6-8, performing heating, performing a stirringreaction for 12-24h, and performing stirring for lowering temperature; adding enough hydrogen peroxide solutions, performing stirring for 3-6h until the reaction is complete, producing precipitation A, and separating the produced precipitation A; adding deionized water, preparing pulp with the separated precipitation A, adding an inorganic coating agent, adjusting the pH to 9-10, and performing areaction for 3-6h to obtain precipitation B; washing the obtained precipitation B to be neutral, separating the washed precipitation B out, performing drying, and performing crushing to obtain yellowish powder C; and enabling an organic coating agent to dissolve in the polydimethylsiloxane to prepare a solution of which the percentage by mass is 10-30%, under high-speed stirring condition, uniformly sprinkling the prepared solution on the obtained yellowish powder C, performing uniform high-speed stirring, performing a heating reaction for 5-10h, and performing crushing to obtain finished products.

Description

technical field [0001] The invention relates to new rare earth materials, in particular to a method for preparing a physical sunscreen for cosmetics. Background technique [0002] In recent years, consumers have begun to worry about the safety of organic chemical substances in sunscreen cosmetics, and people are paying more and more attention to products using inorganic anti-ultraviolet agents. As inorganic anti-ultraviolet agents that can be used in cosmetics, nano-powder titanium oxide and zinc oxide are widely used at present. However, these substances all have problems such as high photocatalytic activity, and when nano-titanium oxide is used on the skin, the skin surface tends to appear unnaturally white. In addition, zinc oxide has problems such as insufficient absorption capacity on the short-wavelength side. In this case, as a new type of inorganic anti-ultraviolet agent, we focus on nano-cerium oxide with a refractive index of 2.10 and an energy band gap of 3.lev....

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Problems solved by technology

[0005] It can be seen from the above two patents that the existing nano-cerium oxide preparation method does not involve the solution of the catalytic activity of nano-cerium oxide oxidation. Therefore, some discoloration, smelly

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