| 摘要 |
A method for producing, by microcasting, a polyurethane foam made from MDI (diphenylmethane diisocyanate) and a polyol with a high ethylene oxide content having an ethylene oxide content greater than 50%, which involves mixing, under pressure, in order to form a foaming liquid precursor of polyurethane foam: - a first reactive liquid, referred to as liquid A, comprising a urethane prepolymer made from a first part of the MDI and a first part of said polyol, and the second part of the MDI in the free state, said prepolymer being in solution in said second part of the MDI in the free state; - with a second reactive liquid, referred to as liquid B, comprising the second part of said polyol and water as the foaming agent, characterised in that the quantity of said polyol in liquid B represents between 25% and 75 % by weight of the total of said polyol; said method is advantageously implemented for casting a polyurethane foam in the cavity of a tyre casing. |
