| 摘要 |
<p>This invention relates to thermoplastic olefin compositions of a low modulus which are suitable for fabrication into flexible skins and liners for applications which heretofore have been serviced by skins and liners produced essentially only from plasticized polyvinyl chloride resin compositions. TPO compositions of this invention comprise an impact modified polypropylene resin and a "plastomer" resin intimately blended in proportions with respect of one to another to provide a blend composition having a 1% secant modulus of less than 40,000 psi, and preferably less than 30,000 psi. Optionally, and preferably, the blend also comprises as a discrete component apart from the impact modified polypropylene an olefin copolymer elastomer or a cross-linked elastomer concentrate. Optionally the blend may contain other polyolefin components to alter its stiffness in desirable ways. In addition to the olefin based polymer components, the blend may further comprise, and preferably does comprise, a coupling agent and activator compound which, during melt compounding of the blend components causes the plastomer to extend to its dimer form and, when a discrete OCE component is present to couple the plastomer thereto.</p> |
