| abstract |
(57) [Abstract] [Purpose] To provide a polyurethane resin for abrasives, which has sufficient hardness, abrasion resistance and alkali resistance. [Structure] A polymer diol (a) containing 70% by weight or more of polyoxytetramethylene glycol having an average molecular weight of 2500 to 5000, 4,4'-diphenylmethane diisocyanate (MDI), and a low molecular diol having a molecular weight of 100 or less (b). A polyurethane resin for abrasives, wherein the content of nitrogen atoms derived from the MDI is 5.5 to 7.0% by weight of the resin. |