Reactive formulations for forming a strong polyurethane-polyurea comprising water blown foam

A reactive foam formulation for forming a polyurethane-polyurea comprising water blown foam, said reactive foam formulation comprising at least:

• An isocyanate composition comprising A equivalents isocyanate compounds, said isocyanate composition having an NCO value in the range 3 up to 50 and a number average isocyanate functionality in the range of 1.8 up to 2.5, and
• B equivalents isocyanate reactive compounds having a molecular weight>500 g/mol and a functionality in the range 1.8 up to 2.5, and
• C urea forming equivalents of water, and
• Optionally D urethane forming equivalents of low molecular weight urethane forming compounds containing hydroxyl functional groups and having a molecular weight<500 g/mol and having a hydroxy functionality in the range 1 up to 8, and
• Optionally E urea forming equivalents of low molecular weight urea forming compounds containing amine functional groups and having a molecular weight<500 g/mol and having a functionality in the range 1 up to 8, and
• At least one catalyst compound, and
• Optionally further additives, additional blowing agents beside water and/or fillers. wherein
• C is in the range of 0.02 up to 0.08 calculated on 100 gram reactive foam formulation, and
• D is in the range of 0 up to 0.07 calculated on 100 gram reactive foam formulation, and
• D+E is greater than 0, and
• D
• +
• E
• C
• is smaller than 1.4, and
• Isocyanate index is in the range 75 up to 125.