| abstract |
Lignin-containing isocyanante prepolymer mixtures are obtainable by reacting (b1) diphenylmethane 4,4'-, 2,4'-and 2,2'-diisocyanate, an isomer mixture of diphenylmethane 4,4'- and 2,4'- or 4,4'-, 2,4'- and 2,2'-diisocyanates or a mixture of diphenylmethane diisocyan-ates and polyphenyl-polymethylene polyisocyanates with a suspension (b2) comprising at least one polyoxyalkylene glycol (b2i) having a molecular weight of from 400 to 6000, preferably from 1000 to 3000, selected from the group of polyoxypropylene glycols, polyoxypropylene-polyoxyethylene glycols and mixtures thereof, and lignin (b2ii). |