| 摘要 |
PURPOSE: Provided is a method for making water blown polyurethane flexible molded foams with improved surface quality using particular silicone polyether copolymers as cell stabilizers. CONSTITUTION: The method for preparing a flexible molded polyurethane comprises reacting an organic polyisocyanate with a polyol in the presence of urethane catalyst, water as a blowing agent, optionally a cell opener, and a silicone surfactant cell stabilizer having the formula:Me3Si(OSiMe2)x(OSiMeG)yOSiMe3, wherein G is a group having the formula -D(OR'')mA where D is a divalent organic linking radical, R'' is an alkylene group, m has an average value from 1 to 5, A denotes an -OR''' or an -OOCR''' group, where R''' is selected from the group consisting of methyl, ethyl, and a combination of methyl and ethyl, x has an average value from 1 to 3 and y has an average value from 0.25 to 1, the value of x/y is from 2.5 to 5 and the value of x+y is from 1.5 to 3.5.
|
