Increased Loose Bulk Density Powders and Polymers Containing Them

Abstract

The invention provides a treated powder having improved loose bulk density comprising a silanized inorganic powder treated with a long chain fatty acid or salts thereof, wherein the amount of the long chain fatty acid is about 0.25% to about 2 wt %, based on the total weight of the treated powder.

1 . A treated powder having improved loose bulk density comprising a silanized inorganic powder treated with a long chain fatty acid or salts thereof, wherein the amount of the long chain fatty acid is about 0.25% to about 2 wt %, based on the total weight of the treated powder, and wherein the loose bulk density of the treated powder is greater than the loose bulk density of an untreated silanized inorganic powder. 
   
   
       2 . The treated powder of  claim 1  wherein the long chain fatty acid has a chain length of about 8 to about 30 carbon atoms. 
   
   
       3 . The treated powder of  claim 2  wherein the long chain fatty acid has a chain length of about 10 to about 20 carbon atoms. 
   
   
       4 . The treated powder of  claim 1  wherein the silanized inorganic powder comprises at least one silane, or a mixture of at least one silane and at least one polysiloxane. 
   
   
       5 . The treated powder of  claim 4  wherein the silane has the formula:
   R 1   x Si(R 2 ) 4-x      
     wherein:
 R 1  is a nonhydrolyzable aliphatic, cycloaliphatic or aromatic group having at least 1 to about 20 carbon atoms; 
 R 2  is a hydrolyzable group selected from the group consisting of alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and 
 x is an integer of 1 up to and including 3. 
 
   
   
       6 . The treated powder of  claim 4  wherein the silane is selected from the group of octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane and octadecyltriethoxysilane. 
   
   
       7 . The treated powder of  claim 5  wherein in the silane, R 1  is a hydrocarbon having 8 to 18 carbon atoms; R 2  is anethoxy group; and x is an integer ranging from 1 up to and including 3. 
   
   
       8 . The treated powder of  claim 4  wherein the polysiloxane has the formula:
   (R 3   n SiO (4-n)/2)m      wherein   R 3  is an organic or inorganic group;   n is ranges from 0 up to and including3; and   m is an integer greater than or equal to 2.   
   
   
       9 . The treated powder of  claim 8  wherein the siloxane is selected from polydimethylsiloxane, vinyl phenylmethyl terminated dimethyl siloxanes, and divinylmethyl terminated polydimethyl siloxane. 
   
   
       10 . The treated powder of  claim 8  wherein the siloxane is polydimethylsiloxane. 
   
   
       11 . The treated powder of  claim 1  wherein the inorganic powder is selected from ZnS, TiO 2 , CaCO 3 , BaSO 4 , ZnO, MOS 2 , talc and clay. 
   
   
       12 . The treated powder of  claim 11  wherein the inorganic powder is TiO 2 . 
   
   
       13 . The treated powder of  claim 12  wherein the loose bulk density of the treated TiO 2  is at least about 1% to about 40% greater than the loose bulk density of an untreated silanized TiO 2  by weight, based on the entire weight of the titanium dioxide. 
   
   
       14 . A polymer composition comprising a polymer and a treated powder, wherein the treated powder has improved loose bulk density and comprises a silanized inorganic powder treated with a long chain fatty acid or salts thereof, wherein the amount of the long chain fatty acid is about 0.25% to about 2 wt %, based on the total weight of the treated powder, and wherein the loose bulk density of the treated powder is greater than the loose bulk density of an untreated silanized inorganic powder. 
   
   
       15 . The polymer composition of  claim 14  wherein the long chain fatty acid has a chain length of about 8 to about 30 carbon atoms. 
   
   
       16 . The polymer composition of  claim 15  wherein the long chain fatty acid has a chain length of about 10 to about 20 carbon atoms. 
   
   
       17 . The polymer composition of  claim 14  wherein the silanized inorganic powder comprises at least one silane, or a mixture of at least one silane and at least one polysiloxane. 
   
   
       18 . The polymer composition of  claim 14  wherein the inorganic 5 powder in the treated powder is selected from ZnS, TiO 2 , CaCO 3 , BaSO 4 , ZnO, MOS 2 , talc and clay. 
   
   
       19 . The polymer composition of  claim 18  wherein the inorganic powder is TiO 2 . 
   
   
       20 . The polymer composition of  claim 19  wherein the loose bulk density of the treated TiO 2  is greater than about 1% greater than the loose bulk density of an untreated silanized TiO 2  by weight, based on the entire weight of the TiO 2 . 
   
   
       21 . The polymer composition of  claim 20  wherein the polymer is selected from polymers of ethylenically unsaturated monomers; polyvinyls; polyvinyl esters; polystyrene; acrylic homopolymers and copolymers; phenolics; alkyds; amino resins; epoxy resins; polyamides; polyurethanes; phenoxy resins; polysulfones; polycarbonates; polyesters and chlorinated polyesters; polyethers; acetal resins; polyimides; and polyoxyethylenes. 
   
   
       22 . The polymer composition of  claim 21  wherein the polymers of ethylenically unsaturated monomers are polyolefins. 
   
   
       23 . The polymer composition of  claim 22  wherein the polyolefin is selected from polyethylene, polypropylene, polybutylene, and copolymers of ethylene with higher olefins or polyvinyl acetate. 
   
   
       24 . A process of preparing a treated powder having improved loose bulk density comprising mixing a silanized inorganic powder with a long chain fatty acid and salts thereof, wherein long chain fatty acid or salt thereof is present in the amount of about 0.25 weight % to about 2 wt %, based on the total weight of the treated powder, and wherein the loose bulk density of the treated powder is greater than the loose bulk density of an untreated silanized inorganic powder. 
   
   
       25 . The process of  claim 24  wherein the mixing is accomplished using a high level of shear. 
   
   
       26 . The process of  claim 24  wherein the mixing is accomplished by spraying the long chain fatty acid or salt thereof and at least one silane, or a mixture of at least one silane and at least one polysiloxane on the inorganic powder and mechanically agitating the mixture. 
   
   
       27 . The process of  claim 24  wherein the mixing may be accomplished by:
 (i) metering at least one silane, or a mixture of at least one silane and at least one polysiloxane, and the long chain fatty acid or salt thereof into a flow restrictor, having an inlet and an outlet, with air or some other motive gas, to create a zone of turbulence at the outlet of the flow restrictor thereby atomizing the at least one silane, or a mixture of at least one silane and at least one polysiloxane, and the long chain fatty acid or salt thereof to form an atomized liquid; and   (ii) contacting the inorganic powder with the atomized liquid to form a treated powder comprising the inorganic powder, at least one silane, or a mixture of at least one silane and at least one polysiloxane, and the long chain fatty acid or salt thereof.