| 摘要 |
1. Modified polyethylene glycols of the general formula HO(CH2 CH2 O)x (RO)y (CH2 CH2 O)z H, in which R is a single or multiple alkyl-substituted alkylene radical having 2 to 4 carbon atoms in the alkylene chain and having methyl, ethyl, propyl or isopropyl as the alkyl-substituent, y is 1 to 2 and the sum of x and z is 5 to 30, neither x nor z being zero, with the proviso that the compound having R = -CH2 CH(CH3 )-, y = 1 and x + z = 5, and the compounds having R = -CH2 C(CH3 )2 CH2 -, y = 1 and x + z = 5 or 6 are excluded.
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