PURPOSE: An elastic support for low-temperature structures excellent in elastic properties at low temperatures, comprising a low-expansion ratio elastomer obtained by reacting an organic polyisocyanate with a polyether-polyol and a chain extender at a specified ratio in the presence of water.
CONSTITUTION: An elastic support comprisng a low-expansion ratio polyurethane elastomer, bulk density of 0.6W0.95g/cm3, obtained by reacting (a) an organic polyisocyanate with (b) a polyether-polyol (average functionality of 2.5W3.5 and number-average MW of 4,500W8,500) and (c) a chain extender at a ratio to provide an NCO index of 90W110 in the presence of water as a blowing agent. The above elastomer is extremely excellent in low-temperature properties; is not brittle down to about -80°C; and has a spring constant which is low in temperature dependency and remains nearly constant over a wide range of temperature (for example, -40W+40°C). Besides, this elastomer is excellent resistances to abrasion, hydrolysis, ozone, flexing fatigue, etc.
SUZUKI TOSHIO
TSUNODA TOMOMI
TAISEI CORP