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|1. (WO2018177990) METHOD FOR PREPARING HIGH RESILIENCE AND SOFT POLYURETHANE FOAM|
|Applicants:||COVESTRO DEUTSCHLAND AG
COVESTRO POLYMERS (CHINA) CO. LTD.
|Title:||METHOD FOR PREPARING HIGH RESILIENCE AND SOFT POLYURETHANE FOAM|
The present invention relates to a method for preparing a high resilience and soft polyurethane foam, comprising the following steps: i) mixing the following components and stirring to give component A as a uniform mixture: al) one or more polyols; a2) one or more small molecule chain extenders with a molecular weight smaller than 200 g/mol; a3) one or more blowing agents; a4) one or more foam stabilizers; a5) carbamide; a6) an organobismuth; wherein the weight ratio of carbamide and organobismuth compound is 2 : 1 to less than 12 : 1; ii) mixing the following component B with the component A to give a reaction mixture: component B, which is one or more polyisocyanates; and iii) reacting the reaction mixture to obtain the high resilience and soft polyurethane foam. The present invention can avoid use of tertiary amine catalyst and organotin by employing a harmless and environmental combination of carbamide and organobismuth as catalyst, while achieving the same foaming and curing effect, thus producing healthier and more environmental polyurethane foam articles with final mechanical properties satisfying usage requirements.