| 摘要 |
PURPOSE: A method for preparing a rigid foam synthetic resin by using water as a foaming agent is provided, to improve the dimension stability even at a high temperature and a high humidity. CONSTITUTION: The method comprises the step of reacting polyol and polyisocyanate in the presence of water, a catalyst and a fluorine-containing compound represented by Rf-O-(A-O)n-R, wherein Rf is a fluorine-containing organic group of C2-C27; n is an integer of 1-100; A is an alkylene group whose straight part comprises two to four carbons and A's are identical or different one another if n is 2-100; and R is an alkyl group of C1-C18 or an acyl group of C1-C18. Preferably the content of the fluorine-containing compound is 0.01-1 parts by weight based on 100 parts by weight of a mixture of polyol and polyisocyanate; and the content of water is 4-16 parts by weight based on 100 parts by weight of the polyol.
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