Schleifmittel und dieses verwendendes Bohrverfahren

摘要

The present invention relates to an abrasive that decreases the heat generation by a core bit due to boring and allows the boring of a deep hole while maintaining the boring speed even when a deep hole is cut using a dry method. This abrasive contains abrasive grains, particles of anhydrous silica having a particle diameter from 5nm to 50nm and silanol groups in the surface thereof or abrasive grains and hydrous resin which discharges water when the hydrous resin is pressed by a core bit or the temperature of the hydrous resin rises, or abrasive grains and a sublimate. The abrasive (51) is supplied between the distal end of a rotating core bit (11) and a working material (20).