Multifunctional coated powders and high solids dispersions

Abstract

A coated powder comprises (a) nanoparticles, and (b) a coating, on the surface of the nanoparticles. The coating comprises (1) silica moieties, (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and (3) poly(dialkyl)siloxane moieties.

1 . A coated powder comprising:
 (a) nanoparticles, and   (b) a coating, on the surface of the nanoparticles, comprising
 (1) silica moieties, 
 (2) organo oxysilane moieties selected from the group consisting of mono-organo oxysilane moieties, bi-organo oxysilane moieties and tri-organo oxysilane moieties, and
 (3) poly(dialkyl)siloxane moieties. 
 
   
     
     
         2 . The coated powder of  claim 1 , wherein the nanoparticles comprise at least one oxide selected from the group consisting of zinc oxides, titanium oxides, silicon oxides, aluminum oxides, iron oxides, bismuth oxides, tin oxides, indium oxides tungsten oxides and rare-earth metal oxides. 
     
     
         3 . The coated powder of  claim 2 , wherein the nanoparticles comprise at least one oxide selected from the group consisting of ZnO, TiO 2 , SiO 2 , Al 2 O 3 , Fe 2 O 3 , CeO 2  Bi 2 O 3 , antimony-tin oxide, indium-tin oxide, doped WO 3 , and mixtures thereof. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The coated powder of  claim 1 , wherein the organo oxysilane moieties each have the formula R 1 nSiO 4-n , with n=1, 2 or 3, and each R1 group is independently selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and heterocyclic radical. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The coated powder of  claim 1 , wherein the poly(dialkyl) siloxane moieties each have the formula O(SiR 2   2 )(R 2   2 SiO) n (SiR 2   2 )O or O(SiR 2   2 )(R 2   2 SiO) n (SiR 2   2 )OR c , where m is an integer of 2 to 14, each R2 group is an alkyl, and Rc is selected from the group consisting of H, methyl, ethyl and propyl. 
     
     
         10 - 19 . (canceled) 
     
     
         20 . The coated powder of  claim 1 , wherein the coated powder is photostable, not chemically reactive, and passes the hydrophobicity test. 
     
     
         21 . A process for producing a coated powder, comprising coating nanoparticles with a polymer, by polymerizing a composition comprising
 (i) the nanoparticles,   (ii) a first alkoxy silane selected from the group consisting of a tetra-alkoxy silane, a poly(tetra-alkoxy silane), and mixtures thereof,   (iii) an organo alkoxysilane selected from the group consisting of mono-organo alkoxysilane, bi-organo alkoxysilane, tri-organo alkoxysilane, and mixtures thereof, and   (iv) a second alkoxy silane selected from the group consisting of a poly(dialkyl)siloxane, and mixtures thereof.   
     
     
         22 . The process of  claim 21 , wherein the nanoparticles comprise at least one oxide selected from the group consisting of zinc oxides, titanium oxides, silicon oxides, aluminum oxides, iron oxides, bismuth oxides, tin oxides, indium oxides tungsten oxides and rare-earth metal oxides. 
     
     
         23 . (canceled) 
     
     
         24 . The process of  claim 21 , wherein the nanoparticles have an average particle size of 10-500 nm. 
     
     
         25 . The process of  claim 21 , wherein the nanoparticles have an average particle size of 15-150 nm. 
     
     
         26 . The process of  claim 21 , wherein the organo alkoxysilane has the formula R 1   n Si(OR b ) 4-n , with n=1, 2 or 3, and each R 1  group is independently selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, and each R b  group is alkyl. 
     
     
         27 - 44 . (canceled) 
     
     
         45 . A dispersion, comprising the coated powder of  claim 1 , and a liquid carrier. 
     
     
         46 . The dispersion of  claim 45 , comprising at least 50% by weight of the coated powder. 
     
     
         47 . (canceled) 
     
     
         48 . (canceled) 
     
     
         49 . The dispersion of  claim 45 , wherein the liquid carrier is cosmetically acceptable. 
     
     
         50 - 70 . (canceled) 
     
     
         71 . A method of protecting skin from light, comprising coating skin with a composition comprising the coated powder of  claim 1 . 
     
     
         72 . A method of protecting skin from light, comprising coating skin with a composition comprising the coated powder of  claim 20 . 
     
     
         73 . (canceled) 
     
     
         74 . A method of protecting skin from light, comprising coating skin with the dispersion of  claim 45 . 
     
     
         75 . (canceled) 
     
     
         76 . A method of preventing or reducing lines and wrinkles on the skin, comprising coating skin with a composition comprising the coated powder of  claim 1 . 
     
     
         77 . A method of preventing loss of elasticity of the skin, comprising coating skin with a composition comprising the coated powder of  claim 1 . 
     
     
         78 . A method of preventing thinning of the skin, comprising coating skin with a composition comprising the coated powder of  claim 1 .