| 摘要 |
PURPOSE:To utilize marked changes in the properties of a polymeric elastomer around its glass transition point with advantage, by deforming a polymeric elastomer molding at a specified temperature, setting it by cooling and restoring its initial shape by heating prior to its use. CONSTITUTION:An isocyanate component such as isophorone diisocyanate is reacted with a polyol component such as a polyoxyalkylene polyol in the presence of a chain extender, a crosslinking agent and, optionally, a catalyst to obtain a polymeric elastomer such as a polyurethane elestomer which has a glass transition temperature (Tg) near the desired set temperature and a modulus of elasticity which changes greatly around the Tg. This elastomer is molded into a molding having a practical shape (e.g., work holding material) 3, which is then deformed into, for example, an easily portable and storable shape 3' by deformation at a temperature of from the Tg to the molding temperature, and is cooled to a temperature <= its Tg to set its deformation. Prior to its use, it is heated to a temperature of from the Tg to its molding temperature to restore its initial shape 3. |
