BLOWING-AGENT-CONTAINING LIGNIN-POLYETHER-POLYOL-BASED ISOCYANATE SEMIPREPOLYMER MIXTURE KEPT UNDER PRESSURE,ITS USE FOR PRODUCING POLYURETHANE FOAM,AND PRODUCTION OF FOAM THEREBY

摘要

A pressurised isocyanate-semi-prepolymer mixt. (I) contg. a propellant/blowing agent (II) is obtd. by reacting: (A) high-mol. wt. poly-hydroxy cpd(s)., specifically alkoxylated lignins with an OH number of 30-80 (A1); and (B) polyisocyanate(s) in the reactor in the presence of (II), or by mixing the isocyanate semi-prepolymer with (II). Also claimed are: (i) a mixt. (I) obtd. as above, in which the prepolymer is obtd. by reacting (A) with (B) in presence of: (C) catalysts; (D) surfactants; opt. (E) blowing agents; and opt. (F) other additives; and (ii) a process for the prodn. of dimensionally stable polyurethane foam.