Porous inorganic fine particles

Abstract

The present invention provides an amorphous porous inorganic substance having small particle sizes and uniform pores, a process for synthesizing the same, and use of the same. The invention provides an amorphous porous inorganic substance having pores of a uniform pore diameter, which has an average particle size D L of 10 to 400 nm as measured by a dynamic light scattering method and a specific surface area difference, S B -S L , between a conversion specific surface area S L calculated from D L and a nitrogen adsorption specific surface area S B obtained by the BET method, of 250 m 2 /g or more. A process for synthesizing the same and use of the same are also disclosed.

1 . A porous substance sol comprising inorganic particles which are amorphous and have uniform pores and which are produced by a process comprising the steps of: 
 mixing a metal source comprising a metal oxide and/or a precursor thereof, a template, and water to prepare a metal oxide/template composite sol; and    removing the template from the composite.    
     
     
         2 . The porous substance sol according to  claim 1 , wherein said process further comprises the step of adding an alkali aluminate.  
     
     
         3 . The porous substance sol according to  claim 1  or  2 , wherein said template is a nonionic surface active agent represented by structural formula (1):  
         HO(C 2 H 4 O) a —(C 3 H 6 O) b —(C 2 H 4 O) c H  (1)  wherein a and c each represent 10 to 110; and b represents 30 to 70, and    wherein said metal source, template and water are mixed at a water to template (water/template) weight ratio ranging from 10 to 1000.    
     
     
         4 . The porous substance sol according to  claim 1  or  2 , wherein said metal source and said template are mixed at a pH ranging from 3 to 12.  
     
     
         5 . The porous substance sol according to  claim 1  or  2 , wherein said metal source is active silica.  
     
     
         6 . The porous substance sol according to  claim 5 , wherein said metal source, template and water are mixed at a weight ratio of said template to said active silica as the metal source in terms of SiO 2 , template/SiO 2 , ranging from 0.01 to 30.  
     
     
         7 . A porous substance obtained from a porous substance sol according to  claim 1  or  2 .  
     
     
         8 . An inkjet recording medium comprising a support and one or more ink absorbing layers provided on the support, 
 wherein at least one of said ink absorbing layer(s) contains a porous substance according to  claim 7 .    
     
     
         9 . A coating liquid for an inkjet recording medium containing a porous substance sol according to  claim 1 .  
     
     
         10 . A coating liquid for an inkjet recording medium containing a porous substance according to  claim 7.