| 摘要 |
A method for manufacturing polyisocyanate is provided to safely prepare polyisocyanate without use of phosgene gas, and to recycle resources by using a polyurethane scrap as a raw material. A method for manufacturing polyisocyanate comprises the steps of: reacting polyurethane scraps with low molecular weight glycol or amine, and heating the scraps to 160~240 ‹C to obtain a depolymerized material; removing polyols and glycol from the depolymerized material, and reacting an amine compound which is the rest intermediate product with a dicarbonate compound to obtain carbamate; and synthesizing isocyanate from carbamate using a silane compound catalyst.
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