POLYURETHANE RESIN COMPOSITION FOR CASTING

PURPOSE:To obtain the titled composition having excellent flex resistance, etc., free from occurrence of stress cracking even in application with compulsory deformation such as fixation to curved surface part because of improved flexibility, by blending a polyol component having a specific composition with an isocyanate component having a specific composition. CONSTITUTION:(A) A polyol component consisting of (i) 50-200pts.wt. polyester triol and polyether triol having 100-1,000 molecular weight, (ii) 30-200pts.wt. polyether diol having 1,000-3,000 molecular weight and (iii) 50-500pts.wt. polycarbonate polyol having 500-2,000 molecular weight obtained by reacting an aliphatic alcohol with ethylene carbonate is blended with (B) an NCO component consisting of (iv) 5-100pts.wt. aliphatic diisocyanate and (v) 0-95pts.wt. reaction product obtained by reacting an alicyclic diisocyanate with a polyether triol having 300-400 reaction in a molar ratio of 0.9-12 in a blending ratio of 0.9-1.2mol. NCO couple in the component B based on 1mol. hydroxyl group of the component A.