| 摘要 |
PURPOSE:To make it possible to form a foam of excellent flame retardancy and adhesiveness even at low temperatures by using chiefly an aromatic polyester polyol as a polyol and a specified three-component catalyst. CONSTITUTION:A polyisocyanate component (e.g., diphenyl-methane diisocyanate) is mixed with a polyol component containing desirably 60-85wt.% aromatic polyester polyol (hydroxyl value of 200-500mgKOH/g) in an NCO/OH equivalent ratio of 1.5-3.0, desirably 1.8-2.7. The mixture is mixed under an elevated pressure with 3.0-10wt.% (total amount of catalyst used) three-component catalyst composed of N,N',N''-tris(diaminopropyl)hexahydro-s-triazine, an alkali metal carboxylate (e.g., potassium octylate) and a lead compound (e.g., lead octylate), a blowing agent, and a foam stabilizer, and the resulting mixture is spray- foamed to obtain urethane-modified polyisocyanurate foam. |
