Cosmetic raw material using core-corona type microparticles and oil-in-water emulsified cosmetic

A cosmetic raw material, comprising:

• a core-corona type microparticles that is obtained by radical polymerization of a polyethylene oxide macromonomer represented by a chemical formula (1), and at least one hydrophobic monomer selected from a group of an acrylate derivative monomer represented by a chemical formula (2) and an acrylamide derivative monomer represented by a chemical formula (3) under the following conditions (A) to (D);
• (A) a molar ratio expressed by a feed molar amount of the polyethylene oxide macromonomer/a feed molar amount of (the acrylate derivative monomer and/or the acrylamide derivative monomer) is 1:10 to 1:250;
• (B) the macromonomer represented by the chemical formula (1) is at least one derivative selected from a group consisting of an acrylic acid derivative and a methacrylic acid derivative that have a polyethylene glycol group with 8 to 200 repeating units,
• the acrylate derivative monomer represented by the following formula (2) is at least one monomer selected from a group consisting of an acrylic acid derivative and a methacrylic acid derivative that have a substituent comprising an alkyl group having 1 to 12 carbon atoms, and
• the acrylamide derivative monomer represented by the chemical formula (3) is at least one monomer selected from a group consisting of an acrylamide derivative and a methacrylamide derivative that have a substituent comprising an alkyl group having 1 to 18 carbon atoms;
• (C) a polymerization solvent is a mixture of alcohol and water,
• wherein the alcohol is at least one alcohol selected from a group consisting of ethanol, dipropylene glycol, 1,3-butylene glycol and isoprene glycol;
• and
• (D) a mass ratio of a solvent composition of the mixed solvent of alcohol and water is in a range of 9 to 1/9 at 20° C.;
• wherein R1 is at least one substitute selected from a group consisting of H and an alkyl group having 1 to 3 carbon atoms, n is a number of 8 to 200, and X is at least one substitute selected from a group consisting of H and CH3;
• wherein R2 is at least one substitute selected from a group consisting of H and an alkyl group having 1 to 3 carbon atoms, and R3 is a substituent that has an alkyl group having 1 to 12 carbon atoms;
• wherein R4 is at least one substitute selected from a group consisting of H and an alkyl group having 1 to 3 carbon atoms, and both R5 and R6 are one substitute selected from a group consisting of H and substituents that have an alkyl group having 1 to 18 carbon atoms.