abstract |
The present invention provides novel cyclic phosphoras-containing compounds, namely hydroxyl-functional phospholene-1-oxides, serving as highly efficient reactive flame retardants in urethane systems, particularly in flexible polyurethane foams, rigid polyurethane foams and rigid polyisocyanurate foams. The invention further provides fire-retarded polyurethane compositions comprising said hydroxyl-functional phospholene-1-oxides. |