PRODUCTION OF POLYURETHANE FOAM

摘要

PROBLEM TO BE SOLVED: To produce a flexible polyurethane foam freed from the necessity for after cure and thereby shortened in an aging time by specifying the relationship concerning a catalyst, a catalyst constant and an isocyanate index, the mixing ratio of the high-molecular and low-molecular polyhydroxy compounds, the amount of TDI used, etc. SOLUTION: The high-molecular polyhydroxy compound used has an average functionality of 2 or above, a rate of primary hydroxyl groups of 50% or above and a hydroxyl value of 20-60mgKOH/g. The low-molecular polyhydroxy compound has an average functionality of 2 or above and a hydroxyl value of 300mgKOH/g or above. The organic polyisocyanate is a mixture of TDI with cr-MDI. Formula I (wherein X is the amount of the catalyst used; k1 and k2 are catalytic constants; I is the isocyanate index; and i is the number of the types of the catalysts used) which represents the relationship between the catalyst and the isocyanate index and formula II concerning the properties (e.g. mixing ratio) of the starting compounds are satisfied.