Process for molding polyurethane utilizing a mixture of two blowing agents
Abstract
Abstract A PROCESS FOR THE PRODUCTION OF UNIFORM POLYURETHANE MOLDINGS SUBSTANTIALLY FREE OF SURFACE VOIDS, BY (1) MIXING A POLYISOCYANATE, A POLYOL, AND A BLOWING AGENT; (2) PRESSING THE RESULTANT LIQUID NONEXPANDED MIXTURE INTO A CLOSED MOLD; (3) ALLOWING THE LIQUID TO EXPAND AND FILL THE MOLD AS THE POLYURETHANE IS FORMED; AND (4) CURING AND REMOVING THE RESULTANT MOLDED ARTICLE; EMPLOYING AS A BLOWING AGENT A MIXTURE OF TWO VOLATILE BLOWING AGENTS, I.E., DICHLORODIFLUOROMETHANE AND TRICHLOROMONOFLUOROMETHANE, WHICH MIXTURE WHEN INCORPO- RATED INTO THE NONEXPANDED LIQUID MOLDING MIXTURE EXHIBITS A VAPOR PRESSURE OF NOT MORE THAN ONE ATMOSPHERE AT 110*F. THE PROCESS IS USEFUL FOR PRODUCTION OF MOLDED ARTICLES FOR STRUCTURAL PURPOSES, FURNITURE, ETC.
Inventors
- 👤 R Harper
Bibliographic Details
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