Cerium-based abrasive, abrasive slurry, and production of cerium-based abrasive

Abstract

There is provided a cerium-based abrasive containing cerium oxide as a main component, in which the abrasive particles composing the abrasive are coated with a coating layer containing at least either one of a silicon component of silicon or a silicon compound and an aluminum component of aluminum or an aluminum compound. The cerium-based abrasive can be produced by wet-dispersing the cerium-based abrasive in a dispersion medium to obtain a slurry and carrying out surface treatment by adding a treatment solution containing at least either one of the silicon compound and the aluminum compound to the slurry. Further, the cerium-based abrasive can be produced by carrying out surface treatment by adding a treatment solution containing at least either one of the silicon compound and the aluminum compound to the slurry during the pulverization step or after the pulverization step in the conventional cerium-based abrasive production process and after that roasting and classifying the obtained cerium-based abrasive.

1 . A cerium abrasive for polishing a glass, containing cerium oxide as a main component and having an average particle diameter of 0.1 to 10 μm, wherein the abrasive particles comprising the abrasive has cerium oxide as a core, and the core is coated with at least one coating layer consisting essentially of an inorganic silicon compound except hydroxide and an inorganic aluminum compound except hydroxide.  
     
     
         2 . The cerium abrasive according to  claim 1 , wherein said coating layer is a single layer in which the inorganic silicon compound except hydroxide and the inorganic aluminum compound except hydroxide are mixed.  
     
     
         3 . The cerium abrasive according to  claim 1 , wherein said coating layer has a double layer structure comprising a first coating layer coating the abrasive particles and a second coating layer coating the first coating layer, and said first coating layer is of the inorganic silicon compound except hydroxide, and said second coating layer is of the inorganic aluminum compound except hydroxide.  
     
     
         4 . The cerium abrasive according to  claim 1 , wherein said coating layer has a double layer structure comprising a first coating layer coating the abrasive particles and a second coating layer coating the first coating layer, and said first coating layer is of the inorganic aluminum compound except hydroxide, and said second coating layer is of the inorganic silicon compound except hydroxide.  
     
     
         5 . The cerium abrasive according to  claim 1 , wherein a content of the inorganic silicon compound except hydroxide and the inorganic aluminum compound except hydroxide contained in the coating layer in total weight of silicon element and aluminum element is 0.01 to 5% by weight of weight of abrasive particles.  
     
     
         6 . The cerium abrasive according to  claim 1 , wherein a repose angle of the abrasive particles is 60 degrees or smaller.  
     
     
         7 . A method to produce the cerium abrasive according to  claim 1 , wherein the method to produce the cerium abrasive comprises the steps of producing a slurry by wet-dispersing the cerium abrasive in a dispersion medium and carrying out surface treatment by adding to the slurry a treatment solution containing at least either one of a silicon compound except hydroxide and an aluminum compound except hydroxide.  
     
     
         8 . The method to produce the cerium abrasive particles according to  claim 7 , wherein said dispersion method contains water as a main component.  
     
     
         9 . The method to produce the cerium abrasive according to  claim 7 , wherein said silicon compound and said aluminum compound contained in the treatment solution are water soluble.  
     
     
         10 . The method to produce the cerium abrasive according to  claim 7 , wherein said treatment solution is added such that a content of silicon element and aluminum element in total is 0.01 to 5% by weight of weight of the cerium abrasive or an abrasive raw material in the slurry.  
     
     
         11 . The method to produce the cerium abrasive according to  claim 7 , wherein pH of the slurry is adjusted to be within a range of 2 to 10 after addition of the treatment solution to carry out the surface treatment.  
     
     
         12 . The cerium abrasive according to  claim 2 , wherein a content of the inorganic silicon compound except hydroxide and the inorganic aluminum compound except hydroxide contained in the coating layer in total weight of silicon element and aluminum element is 0.01 to 5% by weight of weight of abrasive particles.  
     
     
         13 . The cerium abrasive according to  claim 3 , wherein a content of the inorganic silicon compound except hydroxide and the inorganic aluminum compound except hydroxide contained in the coating layer in total weight of silicon element and aluminum element is 0.01 to 5% by weight of weight of abrasive particles.  
     
     
         14 . The cerium abrasive according to  claim 4 , wherein a content of the inorganic silicon compound except hydroxide and the inorganic aluminum compound except hydroxide contained in the coating layer in total weight of silicon element and aluminum element is 0.01 to 5% by weight of weight of abrasive particles.