| 摘要 |
PURPOSE:To obtain economically a polyurethane foam capable of giving high- quality thin-gage sandwich panels or boards, by incorporating specific glycol compound in the raw materials for the foam to improve foam fluidity in its molding, initial bond strength and permanent one. CONSTITUTION:The objective foam can be obtained by incorporating (A) a compound of formula (R is H or 1-4C alkyl; X is 1-4C alkyl or acyl, n=1 or 2) (e.g. ethylene glycol monomethyl ether) in (B) the raw materials for said rigid foam comprising (i) organic polyisocyanate, (ii) polyol, (iii) foaming agent, (iv) catalyst, (v) foam stabilizer in such amounts as to be 0.4-40pts.wt. per 100pts. wt. of the component (B), of the component (A). An equivalent ratio of the polyisocyanate to polyol (NCO/OH) should be 0.8-1.5 (pref. 0.9-1.1). |
