| 摘要 |
PURPOSE:To obtain an antifoaming agent having remarkably small surface tension and high selective orientation property to the boundary of liquid surface and the vapor surface and small susceptibility to temp. and pH by utilizing a reaction product between a polyether polyol compd. and an epoxy compd. CONSTITUTION:The polyether polyol compd. to be used is one having 400- 20,000 average mol.wt. obtd. by the random or block addition polymn. of ethylene oxide or propylene oxide to a compd. having 2-8 active hydrogen atoms. 1-100mol epoxy compd. such as epihalohydrin, styrene oxide, etc. is added to 1mol polyether polyol compd. The antifoaming agent obtd. by this process is used as it is or by diluting with water. Suitable concn. To be used is ca. 0.001- 0.1% to the amt. of the system to be defoamed.
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