METHOD OF MAKING FOOTINGS FROM POLYURETHANE FOAM Russian patent published in 1995 - IPC

FIELD: polymeric compounds. SUBSTANCE: method involves making footings from polyurethane foam by pressing melt mixture consisting of 4, 4′-diphenylmethanediisocyanate and polyol with dye. Before pressing 4, 4′-diphenylmethanediisocyanate is filtered through the fibrous cellulose on the Nutsch filter in heated chamber. After filtration of 4, 4′-diphenylmethanediisocyanate at any storage time on the filter at 45 C filtrate has no any impurities, and content of NCO-groups is at admissible limits. EFFECT: improved method of footing making. 1 tbl