ALEXANDRIA, Va., Sept. 30 -- United States Patent no. 12,428,516, issued on Sept. 30, was assigned to PROPRIETECT LP (Toronto).

"Process for producing a low density free-rise polyurethane foam" was invented by Jing Zhang (Toronto) and Dorota Ulman (Brampton, Canada).

According to the abstract* released by the U.S. Patent & Trademark Office: "There is described a process for producing a free-rise polyurethane foam having a density of less than or equal to about 0.75 pcf. the process comprises the steps of: (a) contacting: (i) an isocyanate, (ii) a first polyol comprising a first polymer chain consisting essentially of propylene oxide units and alkylene oxide units selected from ethylene oxide, butylene oxide and mixtures thereof in a weigh...