| 摘要 |
<p>PURPOSE:To enable the fractionation of a polyolefin resin to be carried out on an industrial scale by means of the fractionally dissolving coacervate technique, by the use of such a mixed solvent from the good and poor solvents of the polyolefin resin to be fractionated that the lower turbidity temperature and dissolving point of the resulting solution system have nearly equal values. CONSTITUTION:A polyolefin resin to be fractinated is brought into contact with such a mixed solvent from the good and poor solvents of said resin (pref. the azeotropic mixture) that the lower turbidity temperature and dissolving point of the resulting solution have vivtually equal volues, more precisely, the difference between both values being <=5 deg.C (pref.<=1 deg.C), to form a liquid/liquid phase system. Thus, oligomers and/or readily soluble substances are fractionated and recovered from one phase, whereas polymeric substances and/or sparingly soluble substances from the other phase. Said good solvent is, e.g., n-pentane, n-hexane, benzene, toluene, tetrahydrofuran. As the examples of the poor solvent, are mentioned methanol, ethanol, acetone, and methyl ethyl ketone.</p> |
