Polyurethanes prodn. from bis:chloroformates and diamines - by reaction as an emulsion in a stirred vertical reactor

摘要

Appts. for synthesising polyurethanes by reacting a diamine (I) with >=1 bischloroformate (II) comprises a cylindrical vertical reactor; an axial stirrer fitted with paddles and 3 staggered feed points. The stirrer has one paddle between the two upper feed points while all the others are below the lowest feed point. The reactor is followed by a decanter, washer and second character. The top feed point is used to introduce an aq. soln. of (I) contg. an emulsifier and acid acceptor; the second a chlorinated aromatic or aliphatic hydrocarbon (III), and the lowest a soln. of (II) in (III). Use of (II) avoids the toxicity problems associated with isocyanates. The reaction occurs preferentially at the water-organic interface of the emulsion maintained in the column.