Verfahren zur Herstellung von Polyurethanpolyisocyanat

Details

Veröffentlichungs-Nr.

EP4821962

Anmeldetag

21. November 2024

Veröffentlichung

12. Juni 2025

Rechtsraum

EP

Abstract

Provided is a method for producing a polyurethane polyisocyanate having stabilized quality without disposing of the unreacted isocyanate monomer discharged from the production process. A method for producing a polyurethane polyisocyanate, comprising the steps of: reacting a TDI (o) having a 2,4-TDI content of 50 to 90% by mass and a polyol (p) to obtain a composition comprising a polyurethane polyisocyanate (A1) and a TDI (o') (step 1); removing the TDI (o') from the composition obtained in the step 1 (step 2); reacting a TDI (q), which is obtained by adding 2,4-TDI to at least part of the TDI (o') so that the resultant TDI (q) has a 2,4-TDI content of 50 to 90% by mass, and a polyol (r) to obtain a composition comprising a polyurethane polyisocyanate (A2) and a TDI (q') (step 3); and removing the TDI (q') from the composition obtained in the step 3 (step 4).

Anmelder

Firma

DIC Corporation

Land

🇯🇵 Japan