| 摘要 |
<p>Polyethylene terephthalate scrap is depolymerized to bis-hydroxyethyl terephthalate and/or its oligomer (BHT) by supplying the scrap, together with ethylene glycol, to a reactor containing molten BHT under the following conditions (a) the molten BHT has a glycol to acid component equivalent ratio of 1.3 to 2.0 (b) the ratio by weight of the acid component of the molten BHT to that of the polyester scrap is 1/4 to 2/1 (c) the ratio of polyester scrap to ethylene glycol is such as to have a glycol to acid component equivalent ratio between the limits of 1.3 to 2.0. The depolymerization is performed at 215 DEG to 250 DEG C. with agitation of the reactants, after which a part of the product in the reactor be removed to a polymerizing reactor.</p> |
