Oil-in-water emulsion sunscreen cosmetic
The present invention is intended to provide an organic UV absorber-free, non-chemical sunscreen cosmetic that contains hydrophobized zinc oxide and/or hydrophobized titanium dioxide as a UV scattering agent, specifically an oil-in-water emulsion sunscreen cosmetic that provides excellent emulsion stability and an excellent pleasant feel while maintaining high levels of UV protection.
1. An organic UV absorber-free, oil-in-water emulsion sunscreen cosmetic that comprises:
(A) zinc oxide and/or titanium dioxide;
(B) isostearic acid;
(C) a silicone containing a carboxyl group;
(D) a non-ionic surfactant;
(E) sodium carboxymethyl cellulose; and
(F) water;
wherein said (A) zinc oxide and/or titanium dioxide is:
hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane; and
homogeneously dispersed in an oil phase with said (C) silicone containing a carboxyl group acting as a dispersant; and
wherein the dispersibility of the zinc oxide or the titanium dioxide lowers without said (B) isostearic acid wherein (C) the silicone containing a carboxyl group is carboxydecyl trisiloxane.
2. The oil-in-water emulsion sunscreen cosmetic according to claim 1 , wherein the contents of the components (A) to (E) with respect to the total amount of the oil-in-water emulsion sunscreen cosmetic are:
3 to 35 mass % for (A) the zinc oxide and/or the titanium dioxide hydrophobized with octyltriethoxysilane and/or dimethylpolysiloxane;
0.1 to 2 mass % for (B) the isostearic acid;
0.1 to 1.5 mass % for (C) the silicone containing a carboxyl group;
0.5 to 4.5 mass % for (D) the non-ionic surfactant; and
0.1 to 1 mass % for (E) the sodium carboxymethyl cellulose.
3. The oil-in-water emulsion sunscreen cosmetic according to claim 1 , further comprising:
(G) a natural polymer or a synthetic high polymer.
4. The oil-in-water emulsion sunscreen cosmetic according to claim 2 , further comprising:
(G) a natural polymer or a synthetic high polymer.
5. A method for making the organic UV absorber-free, oil-in-water emulsion sunscreen cosmetic of claim 1 , the method comprising the steps of:
hydrophobizing (A) the zinc oxide and/or titanium dioxide with octyltriethoxysilane and/or dimethylpolysiloxane; and
dispersing the hydrophobized zinc oxide and/or titanium dioxide homogeneously in an oil phase with (C) carboxydecyl trisiloxane acting as a dispersant;
wherein the dispersibility of the zinc oxide or the titanium dioxide lowers without (B) the isostearic acid.