Modified silane treated pigments or fillers and compositions containing the same

Abstract

The present invention is directed to a composition comprising a white pigment or extended white pigment surface treated with a silane having at least one functional group capable of reacting with acids and anhydrides, at least one polymeric material and a compatibilizer. Once treated, the pigment has improved processability and dispersibility in polymeric materials. Silanizing the pigment also enhances the brightness (increase whiteness and reduce yellowness) of the pigment.

1 . A composition comprising: 
 a) a white pigment or extended white pigment surface treated with a silane having at least one functional group capable of reacting with acids and anhydrides;    b) at least one polymeric material; and    c) a compatibilizer.    
     
     
         2 . The composition of  claim 1  wherein said silane has the following general formula:  
       R x Si(R′) 4-x    
       wherein 
 R is a nonhydrolyzable functional group directly or indirectly bonded to the silicon atom selected from the group consisting of epoxy, isocyanato, mercapto, and mixtures thereof;  
 R′ is a hydrolyzable group selected from the group consisting of alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and  
 x=1 to 3.  
 
     
     
         3 . The composition of  claim 1  wherein said pigment is TiO 2 .  
     
     
         4 . The composition of  claim 1  wherein said extended white pigment is selected from clays, inorganic metal compounds and siliceous materials.  
     
     
         5 . The composition of  claim 1  wherein said compatibilizer comprises copolymers of ethylene or propylene with anhydride or acid groups which are capable of reacting with the functional groups of the at least one polymeric material.  
     
     
         6 . The composition of  claim 1  wherein said compatibilizer comprises copolymers selected from the group consisting of ethylene maleic anhydride copolymers, ethylene (meth)acrylic acid copolymers, propylene maleic anhydride copolymers, propylene acrylic acid copolymers, ethylene propylene copolymers with maleic anhydride or acid functional groups, and olefinic ionomer resins.  
     
     
         7 . The composition of  claim 1  wherein said compatibilizer is present at a concentration of about 0.5 wt. % to about 20 wt. % based on a total weight of the composition.  
     
     
         8 . The composition of  claim 1  wherein said compatibilizer is present at a concentration of about 1% to about 10% by weight of the total composition.  
     
     
         9 . The composition of  claim 1  wherein said filler or pigment is present at a concentration of about 40 wt. % to about 85 wt. % based on a total weight of the Composition.  
     
     
         10 . The composition of  claim 1  further comprising at least one lubricant selected from the group consisting of polysiloxanes, silicone fluids, stearates, paraffinic oils, fluorocarbon fluids, and mixtures thereof.  
     
     
         11 . The composition of  claim 10  wherein said lubricant is a polysiloxane selected from the group consisting of polydimethylsiloxane and organomodified polydimethylsiloxane.  
     
     
         12 . The composition of  claim 13  wherein said lubricant is present from about 0.05 wt. % to about 5 wt. % based on a total weight of the composition.  
     
     
         13 . The composition of  claim 1  wherein said silane is present on the surface of said pigment or extended white pigment in an amount of about 0.1 wt. % to about 5 wt. % based on a weight of said pigment or extended white pigment.  
     
     
         14 . The composition of  claim 1  wherein said polymeric material is selected from the group consisting of olefins and alphaolefins and their copolymers and terpolymers, rubbery block copolymers, polyamides, polyesters, vinylic polymers, acrylics, epoxies, ionomeric resins, and mixtures thereof.  
     
     
         15 . The composition of  claim 14  wherein said polymeric material is selected from the group consisting of polyethylene, ethylene copolymers, polypropylene, propylene copolymers, and mixtures thereof.  
     
     
         16 . A white pigment surface treated with at least one silane capable of reacting with acids and anhydrides and having the following general structure:  
       R x Si(R′) 4-x    
       wherein 
 R is a nonhydrolyzable functional group directly or indirectly bonded to the silicon atom selected from the group consisting of epoxy, isocyanato, mercapto, and mixtures thereof;  
 R′ is a hydrolyzable group selected from the group consisting of alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and  
 x=1 to 3.  
 
     
     
         17 . The white pigment of  claim 16  wherein said white pigment is selected from the group consisting of clays, inorganic metal compounds and siliceous materials.  
     
     
         18 . The white pigment of  claim 16  wherein said white pigment is selected from the group aluminum trihydroxide, magnesium hydroxide, calcined clay, nanoclay, kaolin clay, oxidized brass, oxidized aluminum, oxidized steel, alumina, aluminum trihydrate, fumed silica, precipitated silica, silica aerogels, silica xerogels, aluminum silicates, calcium magnesium silicates, asbestos, molecular sieves, Wallostonite, calcium carbonate, titanium dioxide, calcium sulphate, magnesium sulfate, calcium carbonates having a silica coating, calcium carbonates agglomerated to silica, and mixtures thereof.  
     
     
         19 . The white pigment of  claim 16  wherein said white pigment is TiO 2 .  
     
     
         20 . A white pigment or extended white pigment having enhanced processability and dispersion in polymeric material surface treated with a silane having a structure of:  
       R x Si(R′) 4-x    
       wherein 
 R is a nonhydrolyzable functional group directly or indirectly bonded to the silicon atom selected from the group consisting of epoxy, isocyanato, mercapto, and mixtures thereof;  
 R′ is a hydrolyzable group selected from the group consisting of alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and  
 x=1 to 3; and  
 a polysiloxane having a structure of:  
 (R″ n SiO (4-n)/2 ) m    
 wherein  
 R″ is an organic or an inorganic group;  
 n is 0to 3;and  
 m is equal t o or greater than 2.