Core shell silica particles and use for malodor reduction
The present invention relates to 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, the core shell silica particles prepared by: i) admixing an amount of silica particles in water with an amount of a base, wherein the base comprises a monovalent metal ion, to produce core shell silica particles, each core shell silica particle comprising a silica core, and a surface of the silica core etched with a silicate of the monovalent metal ion; and ii) reacting the core shell silica particles formed in step i) with a metal salt comprising a second metal ion, to form core shell silica particles comprising silicate of the second metal ion on the surface of the silica core.
1. An oral care composition comprising:
one or more core shell silica particles comprising:
a silica core, and
a surface layer etched with a metal silicate, the metal silicate comprising a potassium metal silicate and a multivalent metal silicate; and
an orally acceptable carrier,
wherein the oral care composition has a pH from about 7 to about 10.
2. The oral care composition of claim 1 further comprising a metal salt.
3. The oral care composition of claim 2 , wherein the metal salt is a metal silicate.
4. The oral care composition of claim 1 further comprising a source soluble metal ions.
5. The oral care composition of claim 4 , wherein the source of soluble metal ions is a multivalent metal ion.
6. The oral care composition of claim 4 , wherein the source of soluble metal ions is a monovalent metal ion.
7. The oral care composition of claim 4 , wherein the soluble metal ions are present in an amount up to 0.5 wt. %, based on the total eight of the oral care composition.
8. The oral care composition of claim 7 , wherein the soluble metal ions comprise zinc ions.
9. The oral care composition of claim 1 , wherein the multivalent metal silicate is a divalent metal silicate.
10. The oral care composition of claim 1 , wherein the multivalent metal silicate comprises zinc silicate.
11. The oral care composition of claim 10 , wherein the potassium silicate and the zinc silicate of the one or more core shell silica particles are present in a weight ratio ranging from about 1:1 to about 1:4.
12. The oral care composition of claim 11 , wherein the zinc comprises an amount of up to 20 wt. % of the total amount of metal.
13. The oral care composition of claim 1 , wherein the silica core shell has a d(0.1) ranging from about 6 μm to about 9 μm, a d(0.5) ranging from about 18 μm to about 21 μm, and a d(0.9) ranging from about 41 μm to about 45 μm.
14. An oral care composition comprising:
one or more core shell silica particles comprising:
a silica core having a d(0.1) ranging from about 6 μm to about 9 μm, a d(0.5) ranging from about 18 μm to about 21 μm, and a d(0.9) ranging from about 41 μm to about 45 μm; and
a surface layer etched with a metal silicate, the metal silicate comprising a monovalent metal silicate and a multivalent metal silicate; and
an orally acceptable carrier.
15. The oral care composition of claim 14 , wherein the monovalent metal silicate is potassium silicate.
16. The oral care composition of claim 14 , wherein the oral care composition has a pH of about 7 to about 10.
17. The oral care composition of claim 14 further comprising a source of soluble metal ions present in an amount up to 0.5 wt. %, based on the total eight of the oral care composition.
18. The oral care composition of claim 17 , wherein the soluble metal ions comprise zinc ions.
19. The oral care composition of claim 14 , wherein the monovalent metal silicate comprises potassium silicate and the multivalent metal silicate comprises zinc silicate.
20. The oral care composition of claim 19 , wherein the potassium silicate and the zinc silicate of the one or more core shell silica particles are present in a weight ratio ranging from about 1:1 to about 1:4.