Method for preparing oil-in-water type emulsion composition, and cosmetic material

A method for producing an oil-in-water emulsion composition, comprising the steps of:

• agitating and thereby emulsifying a composition containing:
• (A) from 5 to 35 wt % of an acrylic-silicone graft copolymer which has a weight-average molecular weight of 3,000 to 100,000 and contains constituent units (1) and (2) of the following general formulas
• wherein each R1 is a group independently selected from monovalent hydrocarbon groups, R2 is an alkyleneoxycarbonyl group of 2 to 11 carbon atoms, the alkylene group being limited to a structure that bonds with a silicon atom, R3 and R4 are each independently a hydrogen atom or a methyl group, R5 is an alkyl group of 1 to 22 carbon atoms or a hydrogen atom, m is an integer from 3 to 500, and the molar ratio between the constituent units having general formulas (1) and (2), expressed as (1)/(2), is from 0.02 to 1,
• (B) from 5 to 35 wt % of a volatile oil,
• (C) from 2 to 15 wt % of a polyoxyethylene sorbitan fatty acid ester having an average number of moles of added ethylene oxide (EO) of at least 10 and a hydrophilic-lipophilic balance (HLB) of at least 11, and
• (D) from 15 to 88 wt % of water;
• and
• subsequently treating the emulsified composition under a high shear pressure of from 30 to 300 MPa.