| 摘要 |
A process is provided for the production of synthetic polyurethane plastics, particularly foam plastics, containing biuret groups by reacting polyisocyanates, polyhydroxyl and/or polycarboxyl compounds, flame inhibitors and, if desired, blowing agents, emulsifiers, activators and other additives which is characterized by using as the polyisocyanate solutions in monomeric polyisocyanates of from about 1 per cent to 85 per cent of polyisocyanates containing biuret groups and having the formula: O PARALLEL OCN-R-N-C-N-R-NCO ¦¦ O=C(CO-N)nH ¦¦ R-NCO H--N-CO)n-N ¦¦ R-NCOR ¦ NCO in which R is an aromatic, araliphatic or cycloaliphatic radical which may, if desired, be substituted and N IS AN INTEGER FROM 0 TO 5, WHEREIN THE PROPORTION OF BIURET-POLYISOCYANATES HAVING MORE THAN THREE ISOCYANATE GROUPS IS AT LEAST 20 PER CENT BY WEIGHT BASED ON THE TOTAL QUANTITY OF BIURET-POLYISOCYANATES, AND THE SOLUTIONS CONTAIN FROM ABOUT 0.03 PER CENT TO ABOUT 5 PER CENT BY WEIGHT OF CHEMICALLY COMBINED EMULSIFIERS. |
