| 摘要 |
<p>A flexible polyurethane foam composition characterized by high tensile or tear strength is prepared by reacting an MDI prepolymer, prepared by reacting a MDI having a low functionality with an ethylene oxide-capped polypropylene glycol polyol, with a small amount of a tetraethylene glycol as a cross-linking agent and an ethylene oxide-capped polypropylene glycol polyol, the reaction carried out in the presence of a blowing amount of a blowing agent, such as water or a halocarbon, and a catalytic amount of a polyurethane catalyst, such as a combination of an amine and tetravalent tin catalyst. The addition of a small amount of a chlorinated phosphate flame-retardant agent mixed with the reaction provides for a polyurethane foam composition of good fire retardancy and which when exposed to open flame does not melt, but chars. Further, the addition of a trimerization catalyst provides a foam composition with reduced shrinkage.</p> |
