Preparation of organic additive-treated, pyrogenic silica-encapsulated titanium dioxide particles

Abstract

One aspect of the invention is to provide a composition comprising a titanium dioxide particle having on the surface of said particle a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide; said substantially encapsulating layer having on its surface at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof. Another aspect of the invention is to provide processes for producing said composition.

1 . A composition comprising a titanium dioxide particle having on the surface of said particle a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide; said substantially encapsulating layer having on its surface at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof.  
     
     
         2 . The composition of  claim 1 , wherein the at least one organic surface treatment material is an organo-silane having the formula:  
         R 5   x SiR 6   4-x    wherein    R 5  is a nonhydrolyzable alkyl, cycloalkyl, aryl, or aralkyl group having at least 1 to about 20 carbon atoms;    R 6  is a hydrolyzable alkoxy, halogen, acetoxy, or hydroxy group; and    x=1 to 3.    
     
     
         3 . The composition of  claim 2 , wherein the organo-silane is octyltriethoxysilane.  
     
     
         4 . The composition of  claim 1 , wherein the at least one organic surface treatment material is trimethylolpropane.  
     
     
         5 . The composition of  claim 1 , wherein the pyrogenically-deposited metal oxide is selected from silica, alumina, zirconia, phosphoria, boria, or mixtures thereof.  
     
     
         6 . The composition of  claim 5 , wherein the pyrogenically-deposited metal oxide is silica.  
     
     
         7 . The composition of  claim 1 , wherein the at least one organic surface treatment material is present in a range of from about 0.05 to about 5 wt %.  
     
     
         8 . The composition of  claim 7 , wherein the at least one organic surface treatment material is present in a range of from about 0.1 to about 1.5 wt %.  
     
     
         9 . The composition of  claim 1 , wherein the at least one organic surface treatment material is an organic dispersing agent selected from citric acid, polyacrylic acid, polymethacrylic acid, or polymeric organic dispersing agent having anionic, cationic, zwitterionic, or non-ionic functionality derived from a linear, comb, star, brush, or dendrimer polymer chain and pendant substituent morphology.  
     
     
         10 . The composition of  claim 9 , wherein the organic dispersing agent is present in a range of from about 0.01 to about 1.0 wt %.  
     
     
         11 . A pigment comprising a composition of  claim 1 .  
     
     
         12 . A thermoplastic resin comprising the pigment of  claim 11 .  
     
     
         13 . The thermoplastic resin of  claim 12 , wherein the thermoplastic resin is a polyolefin resin, an acrylic resin, a polyester resin, a polyamide resin, an epoxy resin, a phenolic resin, a poly(vinylaromatic) resin, a poly(vinylhalide) resin, a polycarbonate resin, a fluoropolymer resin, a elastomeric polymer resin, a polyurethaneurea resin, a polyurethane resin, a polyacetal resin, a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyetheretherketone resin, a polyetherketoneketone resin, a liquid crystal polymer resin, or a blend thereof.  
     
     
         14 . The thermoplastic resin of  claim 13 , wherein the polyolefin resin is polyethylene, polypropylene, or a blend or copolymer thereof.  
     
     
         15 . The thermoplastic resin of  claim 14 , wherein the polyethylene is an ultra low density polyethylene, a very low density polyethylene, a linear low density polyethylene, a low density polyethylene, a medium density polyethylene, a high density polyethylene, a high molecular weight high density polyethylene, an ultra high molecular weight high density polyethylene, an ethylene/vinyl acetate co-polymer, an ethylene/methacrylic acid co-polymer, or a blend thereof.  
     
     
         16 . The thermoplastic resin of  claim 14 , wherein the polypropylene is a homopolymer, a copolymer, a compounded olefin, an in situ thermoplastic olefin, or a blend thereof.  
     
     
         17 . The thermoplastic resin of  claim 13 , wherein the acrylic resin is poly(acrylic acid), poly(methacrylic acid), poly(methylacrylate), poly(methylmethacrylate), or a blend thereof.  
     
     
         18 . The thermoplastic resin of  claim 13 , wherein the polyester resin is poly(ethylene terephthalate), poly(butylene terephthalate), poly(cyclohexylene-dimethylene terephthalate), poly(trimethylene terephthalate), poly(ethylene naphthalate), or a blend thereof.  
     
     
         19 . The thermoplastic resin of  claim 13 , wherein the polyamide resin is nylon 6, nylon 6,6, nylon 6/6,6 co-polymer, nylon 11, nylon 6,10, nylon 6,12, amorphous nylon, or a blend thereof.  
     
     
         20 . The thermoplastic resin of  claim 13 , wherein the epoxy resin is poly(epichlorohydrin/bisphenol A); an ester of poly(epichlorohydrin/bisphenol A) and a fatty acid, resin acid, tall oil acid, or a mixture thereof; or a blend thereof.  
     
     
         21 . The thermoplastic resin of  claim 13 , wherein the phenolic resin is derived from the reaction of formaldehyde with phenol, resorcinol, cresol, or p-phenylphenol, or a blend thereof.  
     
     
         22 . The thermoplastic resin of  claim 13 , wherein the poly(vinylaromatic) resin is polystyrene, poly(styrene-acrylonitrile), poly(acrylonitrile-styrene-butadiene), poly(acrylonitrile-styrene-acetate), or a blend thereof.  
     
     
         23 . The thermoplastic resin of  claim 13 , wherein the poly(vinylhalide) resin is poly(vinylchloride), poly(vinylchloride/vinylidene chloride), or a blend thereof.  
     
     
         24 . The thermoplastic resin of  claim 13 , wherein the polycarbonate resin is bisphenol A polycarbonate or is attained by the phosgenation of ethylene glycol or propylene glycol, or is a blend thereof.  
     
     
         25 . The thermoplastic resin of  claim 13 , wherein the fluoropolymer resin is tetrafluoroethylene/perfluoro(propyl vinyl ether) co-polymer, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene/hexafluoropropylene co-polymer, ethylene/tetrafluoroethylene/perfluorobutyl ethylene ter-polymer, ethylene/chlorotrifluoroethylene co-polymer, or a blend thereof.  
     
     
         26 . The thermoplastic resin of  claim 13 , wherein the elastomeric polymer resin is natural rubber, synthetic rubber, an acrylic, chlorosulfonated polyethylene, neoprene, a silicone, a urethane, or a blend thereof.  
     
     
         27 . The thermoplastic resin of  claim 13 , wherein the polyurethane resin is a polyester- or polyether-based polymer derived from 4,4′-dicyclohexylmethane diisocyanate; hexamethyl diisocyanate; isophorone diisocyanate; methylene diphenyl diisocyanate; toluene diisocyanate; tetramethylxylene diisocyanate; o-tolidine diisocyanate; 1,4-cyclohexane diisocyanate; or a blend thereof.  
     
     
         28 . The thermoplastic resin of  claim 13 , wherein the polyurethaneurea resin is a polyester-based spandex, a polyether-based spandex, or a blend thereof.  
     
     
         29 . The thermoplastic resin of  claim 13 , wherein the polyacetal resin is a polyformaldehyde, a copolymer of formaldehyde and ethylene oxide, a copolymer of formaldehyde and 1,3-dioxolane, or a blend thereof.  
     
     
         30 . The thermoplastic resin of  claim 13 , wherein the polyimide resin is obtained by the reaction of pyromellitic dianhydride and p-phenylenediamine.  
     
     
         31 . The thermoplastic resin of  claim 13 , wherein the polyetherimide resin is obtained by the reaction of pyromellitic dianhydride 4,4′-oxydianiline.  
     
     
         32 . The thermoplastic resin of  claim 13 , wherein the polyamideimide resin is obtained by the reaction of trimellitic anhydride acid chloride and 1,4-cyclohexanediamine.  
     
     
         33 . The thermoplastic resin of  claim 13 , wherein the polyetheretherketone is obtained by the reaction of bis(4-chlorophenyl) ketone and hydroquinone.  
     
     
         34 . The thermoplastic resin of  claim 13 , wherein the polyetherketoneketone is obtained by the reaction of diphenyl ether and terephthaloyl chloride.  
     
     
         35 . The thermoplastic resin of  claim 12 , wherein the thermoplastic resin is pigmented by an extrusion application, a molded article application, or a post-article forming coating application.  
     
     
         36 . The thermoplastic resin of  claim 35 , wherein extrusion is performed by cast film extrusion, blown film extrusion, slit film extrusion, sheet and profile extrusion, fiber and filament extrusion, or wire coating extrusion.  
     
     
         37 . The thermoplastic resin of  claim 35 , wherein the molded article application is performed by injection molding, blow molding, or rotational molding.  
     
     
         38 . The thermoplastic resin of  claim 35 , wherein the post-article forming coating application is performed by powder coating, roll-on coating, brush-on coating, trowel-on coating, or spray-on coating.  
     
     
         39 . A method for producing high lacing resistant, semi-photodurable, stabilizer-derived yellowing resistant titanium dioxide particles comprising: 
 (a) providing titanium dioxide particles having on the surface of said particles a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide;    (b) treating said particles with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof; and    (c) optionally, repeating step (b).    
     
     
         40 . The method of  claim 39 , wherein the at least one organic surface treatment material is an organo-silane having the formula:  
         R 5   x SiR 6   4-x    wherein    R 5  is a nonhydrolyzable alkyl, cycloalkyl, aryl, or aralkyl group having at least 1 to about 20 carbon atoms;    R 6  is a hydrolyzable alkoxy, halogen, acetoxy, or hydroxy group; and    x=1 to 3.    
     
     
         41 . The method of  claim 40 , wherein the organo-silane is octyltriethoxysilane.  
     
     
         42 . The method of  claim 39 , wherein the at least one organic surface treatment material is trimethylolpropane.  
     
     
         43 . The method of  claim 39 , wherein the pyrogenically-deposited metal oxide is selected from silica, alumina, zirconia, phosphoria, boria, or a mixture thereof.  
     
     
         44 . The method of  claim 43 , wherein the pyrogenically-deposited metal oxide is silica.  
     
     
         45 . A method for producing high lacing resistant, semi-photodurable, stabilizer-derived yellowing resistant titanium dioxide particles comprising: 
 (a) providing a slurry comprising titanium dioxide particles having on the surface of said particles a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide;    (b) adjusting the pH of the slurry to aid in neutralization of residual chlorine;    (c) adjusting the pH of the slurry to aid in filtration of the slurry;    (d) treating the slurry with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (e) filtering the slurry to produce a filter cake;    (f) optionally, during or after step (e), treating the filter cake with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (g) drying the filter cake;    (h) optionally, during or after step (g), treating the filter cake with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (i) deagglomerating titanium dioxide particles from the treated filter cake; and    (j) optionally, during or after step (i), treating the titanium dioxide particles with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof.    
     
     
         46 . A method for producing high lacing resistant, semi-photodurable, stabilizer-derived yellowing resistant titanium dioxide particles comprising: 
 (a) providing a slurry comprising titanium dioxide particles having on the surface of said particles a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide;    (b) adjusting the pH of the slurry to aid in neutralization of residual chlorine;    (c) adjusting the pH of the slurry to aid in filtration of the slurry;    (d) filtering the slurry to produce a filter cake;    (e) during or after step (d), treating the filter cake with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (f) drying the filter cake;    (g) optionally, during or after step (f), treating the filter cake with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (h) deagglomerating titanium dioxide particles from the treated filter cake; and    (i) optionally, during or after step (h), treating the titanium dioxide particles with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof.    
     
     
         47 . A method for producing high lacing resistant, semi-photodurable, stabilizer-derived yellowing resistant titanium dioxide particles comprising: 
 (a) providing a slurry comprising titanium dioxide particles having on the surface of said particles a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide;    (b) adjusting the pH of the slurry to aid in neutralization of residual chlorine;    (c) adjusting the pH of the slurry to aid in filtration of the slurry;    (d) filtering the slurry to produce a filter cake;    (e) drying the filter cake;    (f) during or after step (e), treating the filter cake with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof;    (g) deagglomerating titanium dioxide particles from the treated filter cake; and    (h) optionally, during or after step (g), treating the titanium dioxide particles with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof.    
     
     
         48 . A method for producing high lacing resistant, semi-photodurable, stabilizer-derived yellowing resistant titanium dioxide particles comprising: 
 (a) providing a slurry comprising titanium dioxide particles having on the surface of said particles a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide;    (b) adjusting the pH of the slurry to aid in neutralization of residual chlorine;    (c) adjusting the pH of the slurry to aid in filtration of the slurry;    (d) filtering the slurry to produce a filter cake;    (e) drying the filter cake;    (f) adding the filter cake into a micronizer;    (g) adding to the micronizer feed block or to conveyed particles up to about several feet past the exit of the micronizer at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof; and    (h) optionally, treating the micronized particles with at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing agent, or a mixture thereof.