Method of Producing Rigid Polyurethane Foams using Recycled Polyurethane Foam Scraps

摘要

Provided is a method for manufacturing a rigid polyurethane foam. According to the present invention, a rigid waste polyurethane foam is collected to be treated in a depolymerization scheme so as to obtain a regenerated polyol, and a new polyol and the regenerated polyol are mixed. The new polyol and the regenerated polyol is mixed in a weight ratio of 40 to 60 : 60 to 40 to obtain a mixed polyol. Also, 6 to 12 parts by weight of imine polyol is mixed with respect to 100 parts by weight of the mixed polyol, and then, an additive and an isocyanate raw material are introduced thereto in a conventional scheme. In addition, an urethane reaction is performed. According to the present invention, the final thickness of a finally obtained urethane foam product can be adjusted by using reaction heat generated during the urethane reaction and reducing a foaming pressure excessively generated during the urethane reaction by the imine polyol which is decomposed at a high reaction temperature.