US2011244382A1PendingUtilityA1

Hydrophobic silica particles and method of producing same

Assignee: CHRISTOPHER ALYSON MPriority: Apr 6, 2010Filed: Apr 6, 2010Published: Oct 6, 2011
Est. expiryApr 6, 2030(~3.7 yrs left)· nominal 20-yr term from priority
G03G 9/09725C01P 2006/12C01P 2002/86Y10T428/2995C09C 1/3081
43
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Claims

Abstract

Hydrophobic silica particles are produced by reacting them with a hydrosiloxane agent.

Claims

exact text as granted — not AI-modified
1 . A method of preparing hydrophobic silica particles comprising:
 a) providing a hydrosiloxane agent having the following formula   
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, CH 3 , 
         R 2 ═—H, —CH 3 . 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  pertluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , or —CH 2 CH 2 R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 Ar, or —Ar, 
         R 6 ═—OH, —OH, —OCH 3 , or —OCH 2 CH 3 , 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, trifluoromethyl, pentafluoromethyl, or —CH 2 CF 3  groups, 
         n, m, and k are integer numbers; n≧1, m≧0, k≧0, with the proviso that when m=k=0, at least one of R 1  and R 2  is —CH 3 , and wherein the hydrosiloxane agent has a molecular weight from 208 to about 20,000; 
         b) contacting silica particles with the hydrosiloxane agent in the presence of a solvent, the solvent, silica particles, and hydrosiloxane agent forming a reaction mixture and wherein, when R 6  is —H, the solvent comprises at least one of water, methanol, and ethanol: and 
         c) drying the reaction mixture to provide hydrophobic silica particles. 
       
     
     
         2 . The method of  claim 1 , wherein the reaction mixture is acidic or basic. 
     
     
         3 . The method of  claim 1 , wherein the silica particles are colloidal silica particles, fumed silica particles, co-fumed silica particles, or precipitated silica particles. 
     
     
         4 . The method of  claim 1 , wherein step b) comprises dispersing the hydrosiloxane agent in an aqueous dispersion of the silica particles. 
     
     
         5 . The method of  claim 4 , wherein the dispersed silica particles are non-aggregated. 
     
     
         6 . The method of  claim 1 , wherein the reaction mixture comprises a second treatment agent. 
     
     
         7 . The method of  claim 1 , further comprising adding a second treatment agent to the reaction mixture. 
     
     
         8 . The method of  claim 1 , wherein the method further comprises combining a second treatment agent with a dispersion of the silica particles before step b). 
     
     
         9 . The method of  claim 1 , wherein the second treatment agent is a hydrophohizing agent or a charge modifying agent. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 1 , wherein step a) comprises modifying a hydrosiloxane precursor having the following formula: 
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, —CH 3 , 
         R 2 ═—H, —CH 3 , 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, or —Ar, 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, trifluoromethyl, pentalluoromethyl, or —CH 2 CF 3  groups, 
         n and m are integer numbers; n≧1, m≧0, with the proviso that when m=0, at least one of R 1  and R 2  is —CH 3 , and wherein the hydrosiloxane precursor has a molecular weight from 208 to about 20,000, 
         by chemically modifying at least a portion of the Si—H groups. 
       
     
     
         12 . The method of  claim 11 , wherein chemically modifying comprises replacing the hydride on at least a portion of the Si—H groups with at least one of an alkoxide, a hydroxide, or R 4 . 
     
     
         13 . (canceled) 
     
     
         14 . The method of  claim 1 , wherein the solvent comprises a water-miscible organic solvent. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 1 , wherein the silica particles in step b) have a particle size of about 5 nm to about 600 nm. 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . A particle composition comprising the reaction product of silica particles and at least a hydrosiloxane agent having the formula 
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, —CH 3 , 
         R 2 ═—H, —Ch 3 , 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, or —Ar, 
         R 6 ═—H, —OH, —OCH 3 , or —OCH 2 CH 3 , 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, trifluoromethyl, penta.fluoromethyl, or —CH 2 CF 3  groups, 
         n, m, and k are integer numbers; n≧1, m≧1, and wherein the hydrosiloxane agent has a molecular weight from 282 to about 20,000. 
       
     
     
         23 . The particle composition of  claim 22 , wherein the silica particles are colloidal silica particles, fumed silica particles, co-fumed silica particles, or precipitated silica particles. 
     
     
         24 . The particle composition of  claim 22 , wherein the particle composition is the reaction product of silica particles with a hydrosiloxane agent and a second treatment agent. 
     
     
         25 . The particle composition of  claim 24 , wherein the second treatment agent is a hydrophobizing agent or a charge-modifying agent. 
     
     
         26 . The particle composition of  claim 22 , wherein the silica particles have a particle size of about 5 nm to about 600 nm. 
     
     
         27 . The particle composition of  claim 22 , wherein the reaction product is in the form of a dry powder. 
     
     
         28 . A toner composition comprising toner particles and the reaction product of silica particles and at least a hydrosiloxane agent having the formula 
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, —CH 3 , 
         R 2 ═—H, —CH 3 , 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 C 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, or —Ar, 
         R 6 ═—OH, —OH, —OCH 3 , or —OCH 2 CH 3 , 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, trifluoromethyl, pentafluoromethyl, or —CH 2 CF 3  groups, 
         n, m, and k are integer numbers; n≧1, m≧0, k≧0, with the proviso that when m=k=0, at least one of R 1  and R 2  is —CH 3 , and wherein the hydrosiloxane agent has a molecular weight from 208 to about 20,000. 
       
     
     
         29 . The toner composition of  claim 28 , wherein the silica particles are colloidal silica particles, fumed silica particles, co-fumed silica particles, or precipitated silica particles. 
     
     
         30 . The toner composition of  claim 28 , wherein the reaction product is the reaction product of silica particles and both a hydrosiloxane agent and a second treatment agent. 
     
     
         31 . The toner composition of  claim 30 , wherein the second treatment agent is a hydrophobizing agent or a charge-modifying agent. 
     
     
         32 . The toner composition of  claim 28 , wherein the silica particles have a particle size of about 5 um to about 600 nm. 
     
     
         33 - 56 . (canceled) 
     
     
         57 . Hydrophobic silica particles prepared by a method comprising:
 a) providing a hydrosiloxane agent having the following formula   
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, —CH 3 , 
         R 2 ═—H, —CH 3 , 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, or —Ar 
         R 6 ═—H, —OCH;, or —OCH 2 CH 3 , 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, trifluoromethyl, pentafluoromethyl, or —CH 2 CF 3  groups, 
         n, m, and k are integer numbers; n≧1, m≧0, k≧0, with the proviso that when m=k=0, at least one of R 1  and R 2  is —CH 3 , and wherein the hydrosiloxane agent has a molecular weight from 208 to about 20,000; 
         h) contacting silica particles with the hydrosiloxane agent in the presence of a solvent, the solvent, silica particles, and hydrosiloxane agent forming a reaction mixture and wherein, when R 6  is —H, the solvent comprises at least one of water, methanol, and ethanol; and 
         c) drying the reaction mixture to provide the hydrophobic silica particles. 
       
     
     
         58 . The hydrophobic silica particles of  claim 57 , wherein the reaction mixture is acidic or basic. 
     
     
         59 . The hydrophobic silica particles of  claim 57 , wherein the silica particles are colloidal silica particles ;  fumed silica particles, co-fumed silica particles, or precipitated silica panicles. 
     
     
         60 . The hydrophobic silica particles of  claim 57 , wherein step b) comprises dispersing the hydrosiloxane agent in an aqueous dispersion of the silica particles. 
     
     
         61 . The hydrophobic silica particles of  claim 60 , wherein the dispersed silica particles are non-aggregated. 
     
     
         62 . The hydrophobic silica particles of  claim 57 , wherein the reaction mixture comprises a second treatment agent. 
     
     
         63 . The hydrophobic silica particles of  claim 57 , further comprising adding a second treatment agent to the reaction mixture. 
     
     
         64 . The hydrophobic silica particles of  claim 57 , wherein the method further comprises combining a second treatment agent with a dispersion of the silica particles before step b). 
     
     
         65 . The hydrophobic silica particles of  claim 62 , wherein the second treatment agent is a hydrophobizing agent or a charge modifying agent. 
     
     
         66 . The hydrophobic silica particles of  claim 57 , wherein step a) comprises modifying a hydrosiloxane precursor having the following formula: 
       
         
           
           
               
               
           
         
         wherein R 1 ═—H, —CH 3 , 
         R 2 ═—H, —CH 3 , 
         R 3 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, —Ar, —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 4 ═—CH 3 , —CH 2 CH 3 , —CH 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , or —CH 2 CH 2 —R f  with R f  being a C 1  to C 8  perfluoroalkyl group, 
         R 5 ═—CH 3 , —CH 2 CH 3 , —CH 2 Ar, —CH 2 CH 2 Ar, or —Ar, 
         Ar is unsubstituted phenyl or phenyl substituted with one or more methyl, halogen, ethyl, tritluoromethyl, pentafluoromethyl, or —CH 2 CF 3  groups, 
         n and m are integer numbers; n≧1, m≧0, with the proviso that when m=0, at least one of R 1  and R 2  is —CH 3 , and wherein the hydrosiloxane precursor has a molecular weight from 208 to about 20,000, 
         by chemically modifying at least a portion of the Si—H groups. 
       
     
     
         67 . The hydrophobic silica particles of  claim 66 , wherein chemically modifying comprises replacing the hydride on at least a portion of the Si—H groups with at least one of an alkoxide, a hydroxide, or R 4 . 
     
     
         68 . The hydrophobic silica particles of  claim 57 , wherein the solvent comprises a water-miscible organic solvent. 
     
     
         69 . The hydrophobic silica particles of  claim 57 , wherein the silica particles in step b) have a particle size of about 5 nm to about 600 nm.

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