Abstract: A process for producing a polyurethane foam from a foam raw material containing polyols, organic isocyanates, catalysts and blowing agents, which comprises using as the polyols a high-molecular weight polyol having a hydroxyl number lower than 100 and a low-molecular weight polyol having a hydroxyl number higher than 200 which are mixed at a ratio of 4:6 to 6:4 (by weight), and also using as the catalysts a tertiary amine alone. Polyurethane forms having good buckling performance can be obtained by the process and they are expected to be useful as a packaging material, shock-absorbing material, heat-insulating material, and so on.

Abstract: A thermochromatic polyurethane foam comprising a polyol and a polyisocyanate as main components, and a thermochromic composition serving as a coloring agent and added to the main components singly or conjointly with a usual dye or pigment. The thermochromic composition comprises an electron-donating chromogenic material, an acidic substance and a solvent.