Hexagonal boron nitride powder and method for producing same
AssigneeTokuyama Corporation
InventorShota DAIKI
Life of this patent
Estimating the term…
Abstract
It is an object of an aspect of the present invention to realize hexagonal boron nitride powder that has high crystallinity and improves thermal conduction properties of resin. In order to attain the object, hexagonal boron nitride powder in accordance with an aspect of the present invention has a ratio of a spectral intensity at a wavelength of 227 nm to a spectral intensity at a wavelength of 330 nm of not less than 1.0, as measured by a cathodoluminescence (CL) method.
Claims7
Hexagonal boron nitride powder having a ratio of a spectral intensity at a wavelength of 227 nm to a spectral intensity at a wavelength of 330 nm of not less than 1.0, as measured by a cathodoluminescence method.
A method for producing hexagonal boron nitride powder, the method comprising:
- (1) a reduction nitridation step of obtaining hexagonal boron nitride by heating a raw material mixture in a furnace under a nitrogen atmosphere to a temperature of not less than 1500° C. and not more than 1850° C. at a heating rate of not more than 10° C./min, the raw material mixture containing an oxygen-containing boron compound, a carbon source, an oxygen-containing calcium compound, and a carbon-containing boron compound;
- (2) an acid cleaning step of cleaning, with acid, the hexagonal boron nitride powder which has been obtained through the reduction nitridation step and which contains an unreacted raw material;
- (3) a heating step in which the hexagonal boron nitride powder after the acid cleaning step is heated to a temperature of more than 1850° C. and less than 2050° C. at a heating rate of not more than 5° C./min;
- (4) a cooling step in which the hexagonal boron nitride powder after the heating step is cooled at a cooling rate of not more than 5° C./min to a temperature of at least 1550° C.;
- and
- (5) a recovery step in which the hexagonal boron nitride powder which has been cooled to a temperature of not more than 50° C. is removed from the furnace after the cooling step.
Dependencies are inferred from the claim text.