Starting material for cosmetics
AssigneeShiseido Company, Ltd.
InventorsYuki Sugiyama, Hirohito Shirakami, Kazuyuki Miyazawa
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Abstract
A starting (raw) material, for cosmetics, comprising a core corona type microgel dispersion obtained by radical polymerization of a specific polyethylene oxide macromonomer, a specific hydrophobic monomer, and a specific cross-linking monomer under specific conditions. The purpose of the present invention is to provide the raw material for cosmetics, with which the cosmetic having a high stability provides a good feeling in use and does not cause skin irritation, can be easily produced.
Claims6
A production method of raw material for cosmetics consisting of a core-corona microgel dispersion comprising:
- the step of a radical polymerization of:
- (A) a polyethylene oxide macromonomer having chemical formula (1),
- wherein R1 is an alkyl group having 1 to 3 carbon atoms, n is a number of 8 to 200 and X is H or CH3;
- (B) a hydrophobic monomer having chemical formula (2),
- wherein R2 is an alkyl group having 1 to 3 carbon atoms, and R3 is an alkyl group having 1 to 12 carbon atoms;
- and
- (C) a cross-linking monomer having chemical formula (3),
- wherein R4 and R5 are independent alkyl group having 1 to 3 carbon atoms, and m is a number of 0 to 2;
- and
- (i) a mole ratio of said polyethylene oxide macromonomer versus said hydrophobic monomer is in the range of 1/10 to 1/250 (mole/mole);
- (ii) said cross-linking monomer is in the range of 0.1 to 1.5% by weight relative to said hydrophobic monomer;
- (iii) said hydrophobic monomer is a monomer composition comprising at least one C1 to C8 methacrylic acid ester;
- (iv) a solvent used for said radical polymerization is a mixed solvent of water and at least one polyol selected from the group consisting of dipropylene glycol, 1,3-butylene glycol, and isoprene glycol, and
- (v) said mixed solvent of water and polyol has a water versus said polyol ratio that is in the range of 90/10 to 10/90% by mass at 20° C.
Dependencies are inferred from the claim text.