Hybrid coated cosmetic powders and methods of making and using same

Abstract

A hybrid coating material and process for pigments and other powders, for example cosmetic powders employs an organometallate, for example a titanate, and a functionalized silicon compound, for example a trialkoxysilane or a functionalized polysiloxane, which covalently bond to each other and to the substrate powder. The coated powders can exhibit excellent hydrophobicity coupled with lipophilicity. Employment of fluorinated silicon compounds may provide hydrophobicity and lipophobicity. Examples show good dispersibility of coated pigments in aqueous, oil and silicone fluids.

1 . A coated powder having a coating on a powder substrate, the coating comprising siloxy metal units.  
     
     
         2 . A coated powder according to  claim 1  comprising chains of multiple siloxy metal units interconnected by oxygen atoms.  
     
     
         3 . A coated powder according to  claim 2  wherein the siloxy metal units have the formula —Si—O—M— wherein M represents a metal having two or more valencies and the additional silicon valencies and metal valencies, if any, are satisfied by chemically inactive groups or atoms compatible with the coated powder and, optionally the siloxy metal unit includes a first oxygen atom boned to the silicon atom and a second oxygen atom bonded to the metal atom.  
     
     
         4 . A coated powder according to  claim 4  having hydrophobic and lipophilic properties or having hydrophobic and lipophobic properties.  
     
     
         5 . A coated powder according to  claim 4  having hydrophobic and lipophilic properties and being dispersible in silicone fluids.  
     
     
         6 . A coated powder according to  claim 4  wherein the coating comprises a continuous, complete, coherent coating extending over substantially the entire outer surface of each powder particle, the coating being tenaciously covalently bonded to the powder substrate.  
     
     
         7 . A coated powder according to  claim 6  wherein the coating includes chains of polysiloxy units coupled to the substrate powder, and metallate units interconnecting polysiloxy units.  
     
     
         8 . A coated powder according to  claim 1  wherein the coating includes the residues of a multifunctional organometallate compound, and of a multifunctional silicon compound.  
     
     
         9 . A coated powder according to  claim 8  wherein the multifunctional organometallate comprises a difunctional organotitanate compound and the multifunctional silicon compound comprises a trialkoxysilane.  
     
     
         10 . A coated powder according to  claim 4  being a cosmetic pigment or filler having an average particle size of not more than about 100 micron.  
     
     
         11 . A coated powder according to  claim 4  wherein the metal M is titanium, aluminum, tin, vanadium, zinc or zirconium.  
     
     
         12 . A coated powder according to  claim 4  wherein the metal M is titanium, and the coating comprises the residue of a chain of siloxy units, the siloxy units being terminated with, or interspersed with, organometallate residues wherein the coating includes crosslinking, terminal units bonded to the powder substrate and terminal units capped with organometallate residues.  
     
     
         13 . A coated powder having a coating on a powder substrate, the coating having chains of units of the following structural formula (8):  
       
         
           
           
               
               
           
         
       
       wherein a is from 1 to 1000, preferably from 1 to 100 and the unsatisfied valencies are occupied by other units of formula (8), said other units optionally being crosslinking units, by powder substrate atoms or groups, or by residual unreactive groups.  
     
     
         14 . A coated powder according to  claim 13  wherein unsatisfied valencies not satisfied by other units are satisfied by hydrocarbon groups, fluorohydrocarbon groups, fatty acid ester groups or mixtures of the foregoing groups.  
     
     
         15 . A lipid- and silicone-dispersible coated cosmetic powder comprising cosmetic powder particles and a hydrophobic coating on the cosmetic powder particles, the hydrophobic coating conferring lipid and silicone dispersibility on the cosmetic powder particles and comprising: 
 a) cosmetically stable hydrophobic organometallate units of formula (R 6 ) g M 1 —O— wherein: 
 M 1  is a metal capable of forming cosmetically stable organometallate compounds of the structure shown, including any of the metals M;  
 a equals the valence state of metal M 1  minus 1 or minus 2, wherein, in the case of the latter alternative, the available valence of metal M 1  is covalently bonded to another M 1  atom or to a coating material oxygen atom;  
 R 6  is a hydrophobic organic moiety including a cosmetically stable covalent bond to metal M or, when a is greater than 1, to an oxygen atom with an available valence and wherein multiple R 6 s, if present, may be the same or different; and  
   b) cosmetically stable siloxy units of formula D-R 7 —R 8 —Si—O—, wherein: 
 D is an oxygen atom with an available valence or a hydrophobic organic moiety including a cosmetically stable covalent bond to the silicon atom; and  
 R 7  and R 8  may be the same or different and are each a hydrophobic organic moiety including a cosmetically stable covalent bond to the silicon atom;  
 wherein the hydrophobic coating is covalently bonded to the cosmetic powder by satisfaction of available oxygen valencies in the organometallate and siloxy units.  
   
     
     
         16 . A coated powder according to  claim 15  wherein R 7  and R 8  include optionally saturated hydrocarbon or fluorohydrocarbon groups having from 1 to 30 carbon atoms and other such groups as will be apparent from the disclosure herein.  
     
     
         17 . A coated powder according to  claim 15  wherein the organometallate units include units having two available oxygen valencies, at least one of the two organometallate unit available oxygen valencies being satisfied by a covalent bond to one of the siloxy units or to another organometallate unit, and wherein the hydrophobic coating includes siloxy units bonded to the powder through organometallate units.  
     
     
         18 . A coated powder according to  claim 15  wherein the siloxy units include units having two available oxygen valencies at least one of the two siloxy unit available oxygen valencies being satisfied by a covalent bond to one of the siloxy units or to another organometallate unit and wherein the hydrophobic coating includes polysiloxy units.  
     
     
         19 . A coated powder according to  claim 15  wherein both the organometallate units and the siloxy units include units having two available oxygen valencies and wherein the hydrophobic coating includes polysiloxy units bonded to the powder through organometallate units.  
     
     
         20 . A coated powder according to  claim 15  comprising a stoichiometric proportion of organometallate units to siloxy units of from about 0.05:1 to about 10:1.  
     
     
         21 . A process of providing a hybrid coating on a cosmetic powder comprising coating the powder with one coating agent comprising a functionalized silicon compound and with another coating agent comprising an organometallate compound under conditions producing a coated powder.  
     
     
         22 . A process according to  claim 21  wherein the powder is simultaneously mixed with the functionalized silicon compound and the organometallate.  
     
     
         23 . A process according to  claim 21  wherein the functionalized silicon compound and the organometallate are applied to the powder sequentially.  
     
     
         24 . A process according to  claim 21  comprising: 
 a) combining: 
 i) a powder to be coated;  
 ii) a liquid dispersion medium sufficient for a slurry;  
 iii) an organometallate compound of formula (1) herein; and  
 iv) a functionalized silicon compound;  
 
 to form a slurry;  
 b) thoroughly mixing the slurry;  
 c) filtering the slurry; and  
 d) heating the resultant paste to a temperature and for a time effective to yield a dry powder.  
 
     
     
         25 . A process according to  claim 24  wherein the functionalized silicon compound comprises a multifunctional silane, a multifunctional polysiloxane, a multifunctional fluorinated or fluoroalkyl-silane or polysiloxane, or a mixture of the foregoing functionalized silicon compounds.  
     
     
         26 . A process according to  claim 21  wherein each coating agents becomes chemically covalently bonded, under the conditions of the coating process, to the surfaces of the powder particles and contributes to the provision of a durable outer layer or skin of a hybrid chemical nature enveloping each powder particle.  
     
     
         27 . A process according to  claim 26  wherein the coating comprises metal atoms, silicon atoms and optionally, M—O—Si groups, as defined herein.  
     
     
         28 . A process according to  claim 27  wherein at least one of the coating agents comprises a bifunctional coupling agent capable of covalently bonding with the substrate powder and with the other coating agent and wherein, optionally, the bifunctional coupling agent has two or more functional entities.  
     
     
         29 . A process according to  claim 21  wherein the coating agents comprise a mixture of organotitanate and trialkoxy alkylsilane coating agents and the coated powder is hydrophobic and lipophilic or hydrophobic and lipophobic.  
     
     
         30 . A process according to  claim 21  wherein the organometallate compound provides a hydrophobic residual unit in the powder coating and optionally comprises a metallate compound having at least one enduring, unreactive, hydrophobic organic group.  
     
     
         31 . A process according to  claim 30 , wherein the enduring organic group comprises a saturated hydrocarbon optionally containing one or more phenyl groups, the saturated hydrocarbon being attached to a metal atom by an oxygen atom and wherein the organometallate comprises at least one displaceable groups or atom attached to the metal atom by an oxygen atom to provide a functional group.  
     
     
         32 . A process according to  claim 21  wherein the organometallate compound is a compound of formula (2) as defined herein.  
     
     
         33 . A process according to  claim 21  wherein the functionalized silicone compound comprises at least one functional entity capable of covalently bonding to a target pigment surface, either directly or through an organometallate residue, under the reaction conditions employed.  
     
     
         34 . A process according to  claim 33  wherein the functional entity comprises: a lower alkoxy group covalently bonded directly to a silicon atom and having from one to four carbon atoms; a halo atom; chloro and amino group; an imino group, and/or a hydroxyl group; and ethylenically unsaturated group; an acrylic group; a methacrylic group; a vinylic group; a halogenated group; a hydroxylated group; a carboxyl or carboxylated group; a thiol or a mercaptan group; an epoxy group; an ester group; a urethane group; a urea group; an amino acid group; or a polypeptide group.  
     
     
         35 . A process according to  claim 21  wherein the functionalized silicon compound has a structure providing a stable residue on the substrate powder and remaining stable throughout subsequent processing, optionally cosmetic formulation.  
     
     
         36 . A process according to  claim 35  wherein the functionalized silicon compound has a silicon backbone structure comprising a single silicon atom, a pair of silicon atoms connected by a single covalent bond or a siloxy chain of formula —(—Si—O—) r  wherein r is an integer of from 2 to 1,000 and wherein, optionally r is from 5 to 100.  
     
     
         37 . A process according to  claim 35  wherein the substituents in functionalized silicon compound, other than the functional entity or groups, lack chemical reactivity in the coating process and form stable entities in the powder coating, the nonfunctional substituents optionally being selected from the group consisting of saturated hydrocarbon groups, saturated fluorohydrocarbon groups, alkyl groups, fluoroalkyl groups, each of the foregoing groups having from 1 to about 50 optionally from about 7 to about 25 carbon atoms per substituent.  
     
     
         38 . A process according to  claim 21  wherein the functionalized silicon compound comprises a functionalized silicon compound according to formula (3), to formula (4), to formula (5) or to formula (6), each formula being as defined herein.  
     
     
         39 . A process according to  claim 21  wherein the functionalized silicon compound comprises a functionalized fluorinated compound or fluorosilane compound according to formula (7) as defined herein.  
     
     
         40 . A process according to  claim 21  comprising conducting the process under conditions causing reaction of both the functionalized silicon compound and the organometallate and causing reaction of one or both of the functionalized silicon compound and the organometallate with the cosmetic powder.  
     
     
         41 . A particulate pigment treated with a reactive titanium species and a reactive silicon species under conditions causing reaction of both the titanium and the silicon species and covalent bonding of the residue or residues of both the titanium species and the silicon species to the pigment surface, providing a coated pigment having hydrophobic properties and lipophilic or hydrophobic and lipophobic properties.  
     
     
         42 . A cosmetic powder coated by a process according to  claim 21 .  
     
     
         43 . A cosmetic product comprising a dispersion of one or more coated powders according to  claim 42 .  
     
     
         44 . A cosmetic product comprising a coated powder according to  claim 1 .  
     
     
         45 . A cosmetic product according to  claim 44  comprising a liquid or powder makeup, a lipstick, a nail enamel, an eye shadow or a mascara.  
     
     
         46 . A cosmetic product comprising a coated powder according to  claim 15 .  
     
     
         47 . A cosmetic product comprising a dispersion of an aqueous phase in an oil or in a silicone phase or a dispersion of an oil or silicone phase in an aqueous phase wherein each phase of the dispersion comprises cosmetic powder particles coated to enhance dispersibility in the disperse medium, a common coating material being used to coat the cosmetic powder particles in both phases of the dispersion.