| 摘要 |
PURPOSE:To obtain a flexible polyurethane foam of excellent gas permeability, by expanding and curing an expandable mixture comprising a specified polyol having a small amount of silica sol, a polyisocyanate compound, a catalyst and a blowing agent. CONSTITUTION:An expandable mixture formed by mixing 100pts.wt. polyol based on at least one kind of a polyoxyalkylene polyol (of an average OH value of 20-80) containing 0.02-0.4wt% silica sol of a particle diameter <=1mu, with a polyisocyanate in an amount to provide an isocyanate index of 90-120, 0.01- 1.0pt.wt. catalyst (e.g., triethylenediamine) and 1-8pts.wt. blowing agent (e.g., water) is expanded and cured under reaction conditions in which the difference between the rise time and the gel time is at least 10sec.
|
