| 摘要 |
<p>PURPOSE:To recover easily polyurethane scrap, by a method wherein the polyurethane scrap is thermally cracked in a specified org. solvent contg. a Tl compd. as a cracking catalyst added thereto, and the resulting cracked liquid as such as recovered, or a polyol produced is separated from the cracked liquid and recovered. CONSTITUTION:A thallium compd. such as thallium oxide or thallium nitrate as a cracking catalyst is added to an org. solvent such as diethylene glycol (DEG), polyoxypropylene glycol (PPG), or dimethylformamide. Polyurethane foam scrap is introduced into the org. solvent contg. the catalyst and thermally cracked at a temp. of 120-200 deg.C. When the org. solvent is DEG, a DEG phase in easily separated from a phase contg. a polyol which was used as a starting material for the production of the foam scrap. Hence, the polyol is separated from the cracked liquid, recovered and reused as the starting material for the production of the foam. When the org. solvent is PPG, the cracked liquid as such is used as the starting material for the production of the foam.</p> |
