Flame resistant corrugated bituminous sheets for building industry - by treating cardboard with compsn. contg. flame retardants prior to impregnating with hot bitument

摘要

Flame resistant corrugated bituminous sheets are prepd. by applying onto the still mat moist surface of an unfinished cardboard an aq. soln. or suspension contg. NH4 salts, a B cpd., an Sb cpd. a silicate, an organic brominated cpd. as well as PVC, shaping the cardboard drying and impregnating with hot bitumen. Direct addn. of the flame retardants into the molten bitumen as avoided and decomposition of these retardants is thus prevented. The sheets are used in the building industry e.g. for roofing, insulating foundation walls, partitions etc.