POLYISOCYANATE FOR RIGID SPRAY FOAM

摘要

PROBLEM TO BE SOLVED: To obtain the subject polyisocyanate used for the in-situ foaming of a rigid spray foam using water as a foaming agent and having excellent executability, etc., by reacting a specific polyisocyanate with a specified modifying agent in a specific proportion. SOLUTION: This polyisocyanate is obtained by reacting (A) a polyisocyanate containing (i) a diphenylmethane diisocyanate (e.g. 4,4'-diphenylmethane diisocyanate and (ii) a polyphenylene polymethylene polyisocyanate in (20-70):(80-30) weight ratio of the components (i):(ii) with (B) a modifying agent comprising a polyether monool or a polyether polyol having 300-2,000 number- average molecular weight and >=70 wt.% content of ethylene oxide in (80-99.99):(20-0.01) weight ratio of the components A:B.