| 摘要 |
PURPOSE:To obtain a foam a stabilizer for rigid polyurethane foam composed of a specified siloxane-oxyalkylene copolymer and capable of improving compatibility of a foaming agent composed of a saturated hydrocarbon, etc., having a specified boiling point, preventing its scattering and producing a low-density urethane foam having high heat insulating properties. CONSTITUTION:An allylpolyoxyalkylene, etc., represented by formula II is mixed and reacted with dimethylmethylhydrogenepolysiloxane, etc., expressed by formula I in the presence of chloroplatinic acid in a solvent such as toluene at 80 to 100 deg.C and the resultant reaction mixture is subsequently neutralized with sodium bicarbonate. After filtration, the solvent is removed, thus producing the objective foam stabilizer composed of a siloxane-oxyalkylene copolymer represented by formula III [R<1> is H, methyl, ethyl, phenyl, etc.; R<2> is a >=3C alkyl; Ra us an organrc substituent of formula TV [R3 is H or a 1 to 19C alkyl; (a) and (b) are 0 or a positive number; a+b>=1; (i) is 1 to 18]; R<b> is R<1>, R<2> or R<a>; (x) and (y) are 0 or a positive number; (z) is a positive number for a foaming agent composed of a saturated hydrocarbon, etc., having <=85 deg.C boiling point under the ordinary pressure. |
