Tooth whitening oral care product with core shell silica particles
The present invention provides a tooth whitening oral care composition comprising: (i) a dye having a blue to blue-violet color with a hue angle in the CIELAB system ranging from 200 to 320 degrees; (ii) core shell silica particles, wherein each core shell silica particle comprises a silica core, and a surface of the silica core is etched with metal silicate; (iii) an orally acceptable carrier vehicle comprising a non-aqueous solvent; and wherein the composition comprises water in an amount of from 3 weight % to 30 weight %.
1. A tooth whitening oral care composition comprising:
(i) a dye having a blue to blue-violet color with a hue angle in the CIELAB system ranging from 200 to 320 degrees;
(ii) core shell silica particles, wherein each core shell silica particle comprises a silica core, and a surface of the silica core is etched with metal silicate;
(iii) an orally acceptable carrier vehicle comprising a non-aqueous solvent; and
wherein the composition comprises water in an amount of from 3 weight % to 30 weight %.
2. The composition according to claim 1 , wherein the metal silicate for each core shell silica particle is:
i) a metal silicate of a monovalent metal ion; or
ii) a metal silicate of a monovalent metal ion and one or more of a of a divalent metal ion, a trivalent metal ion, and a tetravalent metal ion.
3. The composition according to claim 2 , wherein the monovalent metal ion is a group I metal ion.
4. The composition according to claim 1 , wherein the metal silicate comprises the formula M 1 2 SiO3.x H 2 O, wherein M 1 is a monovalent metal ion, optionally a group I metal, and x is from 0 to 10; and the outer 10 nm depth of a core shell silica particle comprises from 0.1 to 10 weight % M 1 2 SiO3.xH 2 O.
5. The composition according to claim 1 , wherein the outer 10 nm depth of a core shell silica particle has the general formula:
(SiO 2 ) p [O o *N + n H + h OH − j )]. q H 2 O
wherein O* is oxygen in the silicate form; N is a group I metal ion; p, o, n, h, j and q are the atomic percentages of each component; and the total charge of each core shell silica particle is zero.
6. The composition according to claim 1 , wherein the metal silicate comprises a silicate of a group 2 metal ion, a transition metal ion, a group 13 metal ion, a group 14 metal ion or mixtures thereof.
7. The composition according to claim 1 , wherein the metal silicate comprises the formula M 2 SiO3.x H 2 O, wherein M 2 is a divalent metal ion selected from the group consisting of Zn, Ca, Mg, Sn, and Sr, and x is from 0 to 10.
8. The composition according to claim 6 , wherein the outer 10 nm depth of each particle has the general formula:
(SiO 2 ) p [O* o N + n M 2+ m U 3+ u V 4+ v H + h OH − j ].q H 2 O
wherein O* is oxygen in the silicate form; N is a monovalent metal ion; M is a divalent metal ion; U is a trivalent metal ion; V is a tetravalent metal ion; p, o, n, m, u, v, h, j and q are the atomic percentages of each component; and the total charge of each core shell silica particle is zero.
9. The composition according to claim 1 , wherein the d(0.5) value of the core shell silica particles ranges from 5 nm to 50 μm.
10. The composition of claim 1 , wherein the amount of core shell silica particles is 0.001 to 10 weight % of the composition.
11. The composition of claim 1 , wherein the dye comprises from 0.001 to 2 weight % of the composition.
12. The composition according to claim 1 , wherein the dye comprises a metal ion.