Recording Sheet for Ink Jet Printing

Abstract

A method for the preparation of silicon dioxide dispersions is described, wherein the surface of the silicon dioxide is modified by a treatment with the reaction products of a compound of trivalent aluminum with least one aminoorganosilane. These reaction products are formed in a separate reaction step. The present invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

1 . Method of preparation of surface modified silicon dioxide, wherein the surface of the silicon dioxide is modified by a treatment with the reaction products of a compound of trivalent aluminum with at least one aminoorganosilane. 
     
     
         2 . The method of according to  claim 1 , wherein said reaction products contain Al—O—Si linkages. 
     
     
         3 . The method according to  claim 1 , wherein said compound of trivalent aluminum is selected from the group consisting of aluminum chloride, aluminum nitrate, aluminum acetate, aluminum formiate, aluminum chlorohydrate or mixtures of these compounds. 
     
     
         4 . The method according to  claim 1 , wherein said aminoorganosilane is of formula (I) 
       
         
           
           
               
               
           
         
       
       wherein 
       R 1 , R 2 , R 3  independently represent hydrogen, hydroxyl, unsubstituted or substituted alkyl with 1 to 6 carbon atoms, unsubstituted or substituted aryl, unsubstituted or substituted alkoxyl with 1 to 6 carbon atoms or unsubstituted or substituted aryloxyl 
       and 
       R 4  represents an organic moiety substituted by at least one primary, secondary or tertiary amino group. 
     
     
         5 . The method according to  claim 4 , wherein said substituents of R 1 , R 2  and R 3  are independently selected from the group consisting of thiol, sulfide and polyalkylene oxide. 
     
     
         6 . The method according to  claim 4 , wherein said aminoorganosilane is selected from the group consisting of 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, (3-triethoxysilylpropyl)-diethylenetriamine, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, (3-triethoxysilylpropyl)-diethylenetriamine or mixtures thereof. 
     
     
         7 . The method according to  claim 1 , wherein the amount of said compound of trivalent aluminum is from 0.1 to 20 percent by weight relative to the amount of silicon dioxide. 
     
     
         8 . The method according to  claim 1 , wherein the value of pH of the solution containing the reaction products of the compound of trivalent aluminum with said aminoorganosilane is between 3 and 10. 
     
     
         9 . The method according to  claim 1 , wherein said silicon dioxide is fumed silicon dioxide. 
     
     
         10 . The method according to  claim 9 , wherein said fumed silicon dioxide has a specific surface between 20 m 2 /g and 400 m 2 /g. 
     
     
         11 . The method according to  claim 9 , wherein a mixture of two or more different fumed silicon dioxides having different specific surfaces is used. 
     
     
         12 . The method according to  claim 11 , wherein the surface modification of the different fumed silicon dioxides is done simultaneously in their mixture. 
     
     
         13 . The method according to  claim 11 , wherein the surface modification of the different fumed silicon dioxides is done individually for each fumed silicon dioxide. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled)