| 摘要 |
PURPOSE:To manufacture efficiently a high-quality leather-wrapped steering wheel product which is excellent in hardness stability and reactivity when it is manufactured. CONSTITUTION:In a steering wheel provided with a core part and a covering part composed of polyester base semi-hard urethane foam to cover the core part, assuming that a total of ethylene oxide and propylene oxide is 100 pts.wt., the content of the ethylene oxide in polyester polyole to form the semi hard urethane foam is 7-13 pts.wt. (particularly, 10-13 pts.wt.). In this case, mainly in hardness of the semi-hard urethane foam, the hardness under relative humidity of 90% has a performance capable of showing a value of not less than 80% (or a difference between both is not more than 10 degrees) under relative humidity of 40%. |
