Method for producing nitridosilicate-based compound, nitridosilicate phosphor, and light-emitting apparatus using the nitridosilicate phosphor

Abstract

A nitridosilicate-based compound is produced by reacting an alkaline-earth metal compound capable of generating an alkaline-earth metal oxide by heating or a rare earth compound capable of generating a rare earth oxide by heating with at least a silicon compound, while the alkaline-earth metal compound or the rare earth compound is being reduced and nitrided by the reaction with carbon in an atmosphere of nitriding gas. Because of this, a nitridosilicate-based compound of high quality can be produced industrially at low cost.

1 - 17 . (canceled) 
   
   
       18 . A method for producing a compound by a reducing nitriding reaction in which a sintering material is reduced and nitrided by a reaction with carbon in an atmosphere of nitriding gas,
 wherein the compound is a nitridosilicate-based compound, and   the nitridosilicate-based compound is a compound containing at least an alkaline-earth metal element or a rare earth element, silicon, and nitrogen as main constituent elements, and excluding SIALON represented by a general formula: M′ p/2 Si 12−p−q Al p+q O q N 16−q  (where M′ is Ca or Ca combined with Sr; q is 0 to 2.5; and p is 1.5 to 3).   
   
   
       19 . The method for producing a compound according to  claim 18 , wherein the nitridosilicate-based compound is any compound selected from nitridosilicate, oxonitridosilicate, nitridoaluminosilicate, and oxonitridoaluminosilicate. 
   
   
       20 . The method for producing a compound according to  claim 18 , wherein the nitridosilicate-based compound is a highly nitrided nitridosilicate-based compound, and the highly nitrided nitridosilicate-based compound is a nitridosilicate-based compound in which the number of atoms of oxygen is smaller than that of alkaline-earth metal per mol of the nitridosilicate-based compound or a nitridosilicate-based compound in which the number of atoms of oxygen is smaller than the number obtained by multiplying the number of atoms of rare earth metal by 1.5 per mol of the nitridosilicate-based compound. 
   
   
       21 . The method for producing a compound according to  claim 20 , wherein the nitridosilicate-based compound is at least one compound selected from M 2 Si 5 N 8 , MSi 7 N 10 , M 2 Si 4 AlON 7 , MSiN 2 , and CaAlSiN 3 , and the M is at least one element selected from Mg, Ca, Sr, and Ba. 
   
   
       22 . The method for producing a compound according to  claim 18 , wherein the nitriding gas is at least one gas selected from nitride gas and ammonia gas. 
   
   
       23 . The method for producing a compound according to  claim 22 , wherein the carbon has any shape selected from solid-state carbon, amorphous carbon, and carburizing gas. 
   
   
       24 . The method for producing a compound according to  claim 18 , wherein the sintering material contains at least one compound selected from an alkaline-earth metal compound capable of generating an alkaline-earth metal oxide MO (where M is at least one element selected from Mg, Ca, Sr, and Ba; O is an oxygen element) by heating and a rare earth compound capable of generating a rare earth oxide LnO or Ln 2 O 3  (where Ln is at least one element selected from rare earth elements of atomic numbers 21, 39, and 57-71; O is an oxygen element), and a silicon compound. 
   
   
       25 . The method for producing a compound according to  claim 24 , wherein the alkaline-earth metal compound is at least one alkaline-earth metal compound selected from a carbonate, an oxalate, an oxide, and a hydride of alkaline earth metal. 
   
   
       26 . The method for producing a compound according to  claim 24 , wherein the rare earth compound is at least one rare earth compound selected from a carbonate, an oxalate, an oxide, and a hydride of a rare earth element. 
   
   
       27 . The method for producing a compound according to  claim 24 , wherein the silicon compound is at least one silicon compound selected from silicon nitride, silicon oxynitride, silicon oxide, and silicon diimide. 
   
   
       28 . The method for producing a compound according to  claim 18 , wherein the reaction is performed by heating. 
   
   
       29 . The method for producing a compound according to  claim 28 , wherein a reaction temperature is 1400° C. to 2000° C. 
   
   
       30 . The method for producing a compound according to  claim 18 , wherein the compound is a phosphor. 
   
   
       31 . The method for producing a compound according to  claim 30 , wherein the phosphor contains at least one element selected from Ce, Pr, Eu, Tb, and Mn. 
   
   
       32 . The method for producing a compound according to  claim 31 , wherein a reaction atmosphere is a reducing atmosphere using hydrogen. 
   
   
       33 . The method for producing a compound according to  claim 30 , wherein the phosphor is excited with light having an emission peak in a near-ultraviolet or blue wavelength region of more than 340 nm to 500 nm and converts the light into visible light with a wavelength longer than a peak wavelength of the light. 
   
   
       34 . A phosphor containing a compound obtained by the production method according to  claim 20  as a phosphor base material, and containing an element that is to be a luminescent center. 
   
   
       35 . The phosphor according to  claim 34 , wherein the compound contains alkaline earth metal as a main component and Eu 2+  ions or Ce 3+  ions as the luminescent center. 
   
   
       36 . A light-emitting apparatus using the phosphor according to  claim 34  as a light-emitting source.