Patent ID: 7326378

Claim:
A process for producing a polyurethane grinding tool, the process comprising the steps of: mixing one or more types of polyol component selected from the group consisting of polyether polyols and polyester polyols with inorganic abrasive grains; mixing an organic polyisocyanate component with inorganic abrasive grains; the total amount of inorganic abrasive grains added and mixed with the polyol component and the organic polyisocyanate component is 1.0 to 2.0 as a ratio by weight relative to the total amount of the polyol component and the organic polyisocyanate component; uniformly mixing the polyol component mixed with the abrasive grains and the polyisocyanate component mixed with the abrasive grains by means of a rotary-static mixer; foam molding the mixture thus obtained by reacting the mixture in a mold so that the bulk density is 0.40 to 0.60 g/cm 3 ; and machining the molded grinding tool so that the plan shape thereof is any one of a regular polygon having four to twenty sides, a gear wheel, and an arced polygon.