Patent ID: 8657893

Claim:
A method for producing a sintered cubic boron nitride compact, the method comprising: a step of deflocculating, in which secondary particles in boron nitride starting powders are deflocculated by dispersing the boron nitride starting powders in a solution of a deflocculant to be a dispersion liquid; a step of removing, in which the solution of deflocculant is removed from the dispersion liquid after the step of deflocculating; a step of molding, in which the boron nitride starting powders, which have been deflocculated, are molded to form a green compact after the step of removing; and a step of sintering, in which the green compact is pressurized at 5 GPa or higher and heated at 1400° C. or higher in the presence of a supercritical fluid source, the supercritical fluid source is put into a supercritical state, and the green compact is sintered, after the step of molding, wherein a content ratio of the deflocculant in the dispersion liquid ranges from 0.1 to 5 wt % of a sum of the deflocculant and the cubic boron nitride starting powders as a weight.