Reaction injection molded elastomer containing an internal mold release made by a two-stream system

摘要

The invention is a method of making a molded reaction injection molded elastomer which will release from its mold without the presence of externally applied mold release agents. The reaction injection molded (RIM) elastomer is made by injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream amine terminated polyethers of greater than 1,500 molecular weight, an amine terminated chain extender and an internal mold release agent, and in the second stream an aromatic polyisocyanate. The resulting RIM elastomer may be removed from the mold easily. RIM elastomers are useful, for example, for automobile body parts.