Silicon coated metal microparticles, silicon compound coated metal microparticles, and production method thereof

Abstract

The present invention relates to silicon coated metal microparticles in which at least a part of a surface of a metal microparticle composed of at least one of metal elements or metalloid elements is coated with silicon, wherein the silicon coated metal microparticles are a product obtained by a reduction treatment of silicon compound coated precursor microparticles in which at least a part of a surface of a precursor microparticle containing a precursor of the metal microparticles is coated with a silicon compound, or silicon doped precursor microparticles containing a precursor of the metal microparticles. Because it is possible particularly to strictly control a particle diameter of the silicon compound coated metal microparticle by controlling conditions of the reduction treatment, design of a more appropriate composition can become facilitated, compared with a conventional composition, in terms of diversified usages and desired properties of silicon compound coated metal microparticles.

1 . A method of producing silicon compound coated metal microparticles in which at least a part of a surface of a metal microparticle composed of art least one of metal elements or metalloid elements is coated with a silicon compound,
 wherein silicon compound coated precursor microparticles in which at least a part of a surface of a precursor microparticle containing a precursor of the metal microparticles is coated with a silicon compound, or silicon doped precursor microparticles containing a precursor of the metal microparticles, are subjected to a reduction treatment up to silicon compound coated metal microparticles.   
     
     
         2 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated precursor microparticles or the silicon doped precursor microparticles are subjected to a reduction treatment up to silicon coated metal microparticles, and the surface layer of the silicon coated metal microparticles obtained by the reduction treatment is subjected to an oxidation treatment.   
     
     
         3 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein a primary particle diameter of the silicon compound coated precursor microparticles or the silicon doped precursor microparticles is 100 nm or less.   
     
     
         4 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the reduction treatment is a heart treatment of powders of the silicon compound coated precursor microparticles or the silicon doped precursor microparticles under a reduction atmosphere, and   a particle diameter of the silicon compound coated metal microparticles is controlled by controlling a heat treatment temperature and a treatment time under the reduction atmosphere.   
     
     
         5 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein a particle diameter of the silicon compound coated metal microparticles after the reduction treatment is increased more than that of the silicon compound coated precursor microparticles or the silicon doped precursor microparticles before the reduction treatment.   
     
     
         6 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated precursor microparticles are silicon compound coated precursor microparticles in which at least a part of a surface of one precursor microparticle is coated with a silicon compound,   a primary particle diameter of the precursor microparticle is 100 nm or less, and   a primary particle diameter of the silicon compound coated precursor microparticle is 100.5% or more and 190% or less relative to a primary particle diameter of the precursor microparticle.   
     
     
         7 . The method of producing silicon compound coated metal microparticles according to  claim 1 , wherein the silicon compound coated precursor microparticles are core-shell type silicon compound coated precursor microparticles in which entire surface of one core precursor microparticle is coated with a shell silicon compound. 
     
     
         8 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated precursor microparticles are silicon compound coated precursor microparticles in which at least a part of a surface of an aggregate of a plurality of precursor microparticles is coated with a silicon compound, a diameter of the aggregate is 100 nm or less, and   a particle diameter of the silicon compound coated precursor microparticle is 100.5% or more and 190% or less relative to a diameter of the aggregate.   
     
     
         9 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated precursor microparticles or silicon doped precursor microparticles contain silicon inside the precursor microparticles before a heat treatment under a reduction atmosphere, and   at least a part of the silicon is transferred from the inside of the precursor microparticles in the outer peripheral direction, as compared with the state before the heat treatment under a reduction atmosphere.   
     
     
         10 . The method of producing silicon compound coated metal microparticles according to  claim 1 , wherein the silicon compound contains an amorphous silicon compound. 
     
     
         11 . The method of producing silicon compound coated metal microparticles according to  claim 1 , wherein the precursor is at least one selected from a salt, an oxide, a hydroxide and a hydroxide oxide of at least one of metal elements or metalloid elements constituting the silicon compound coated metal microparticles. 
     
     
         12 . The method of producing silicon compound coated metal microparticles according to  claim 1 , wherein the precursor contains an amorphous precursor, 
     
     
         13 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated metal microparticles are silicon compound coated metal microparticles in which at least a part of a surface of one metal microparticle is coated with a silicon compound,   a primary particle diameter of the metal microparticle is 1 μm or less, and a primary particle diameter of the silicon compound coated metal microparticle is 100.5% or more and 190% or less relative to a primary particle diameter of the metal microparticle.   
     
     
         14 . The method of producing silicon compound coated metal microparticles according to  claim 13 , wherein the silicon compound coated metal microparticles are core-shell type silicon compound coated metal microparticles in which entire surface of one core metal microparticle is coated with a shell silicon compound. 
     
     
         15 . The method of producing silicon compound coated metal microparticles according to  claim 1 ,
 wherein the silicon compound coated metal microparticles are silicon compound coated metal microparticles in which at least a part of a surface of an aggregate of a plurality of metal microparticles is coated with a silicon compound,   a diameter of the aggregate is 1 μm or less, and.   a particle diameter of the silicon compound coated metal microparticle is 100.5% or more and 190% or less relative to a diameter of the aggregate.   
     
     
         16 . The method of producing silicon compound coated metal microparticles according to  claim 1 , wherein the metal elements or metalloid elements comprise at least one selected from the group consisting of nickel, iron, silicon and aluminum. 
     
     
         17 . Silicon coated metal microparticles in which at least a part of a surface of a metal microparticle composed of at least one of metal elements or metalloid elements is coated with silicon,
 wherein the silicon coated metal microparticles are a product obtained by a reduction treatment of silicon compound coated precursor microparticles in which at least a part of a surface of a precursor microparticle containing a precursor of the metal microparticles is coated with a silicon compound, or silicon doped precursor microparticles containing a precursor of the metal microparticles.   
     
     
         18 . Silicon compound coated metal microparticles in which at least a part of a surface of a metal microparticle composed of at least one of metal elements or metalloid elements is coated with a silicon compound,
 wherein the silicon compound coated metal microparticles are one selected from the following (a) to (d):   (a) silicon compound coated metal microparticles obtained by a reduction treatment of silicon compound coated precursor microparticles in which at least a part of a surface of a precursor microparticle containing a precursor of the metal microparticles is coated with a silicon compound, followed by an oxidation treatment of a surface of the obtained silicon compound coated metal microparticles,   (b) silicon compound coated metal microparticles obtained by a reduction treatment of silicon doped precursor microparticles containing a precursor of the metal microparticles, followed by an oxidation treatment of a surface of the obtained silicon compound coated metal microparticles,   (c) silicon compound coated metal microparticles obtained by a reduction treatment of silicon compound coated precursor microparticles in which at least a part of a surface of a precursor microparticle having a primary particle diameter of 100 nm or less containing a precursor of the metal microparticles is coated with a silicon compound, and   (d) silicon compound coated metal microparticles obtained by a reduction treatment of silicon doped precursor microparticles having a primary particle diameter of 100 nm or less containing a precursor of the metal microparticles,   
     
     
         19 . The silicon compound coated metal microparticles according to  claim 18 ,
 wherein the silicon compound coated precursor microparticles are silicon compound coated precursor microparticles in which at least a part of a surface of one precursor microparticle is coated with a silicon compound,   a primary particle diameter of the precursor microparticle is 100 nm or less, and a primary particle diameter of the silicon compound coated precursor microparticle is 100.5% or more and 190% or less relative to a primary particle diameter of the precursor microparticle.   
     
     
         20 . The silicon compound coated metal microparticles according to  claim 18 , wherein the silicon compound coated precursor microparticles are core-shell type silicon compound coated precursor microparticles in which entire surface of one core precursor microparticle is coated with a shell silicon compound.