Elastic blends comprising crystalline polymer and crystallizable polymers of propylene

Abstract

Improved thermoplastic polymer blend compositions comprising an isotactic polypropylene component and an alpha-olefin and propylene copolymer component, said copolymer comprising crystallizable alpha-olefin sequences. In a preferred embodiment, improved thermoplastic polymer blends are provided comprising from about 35% to about 85% isotactic polypropylene and from about 30% to about 70% of an ethylene and propylene copolymer, wherein said copolymer comprises isotactically crystallizable propylene sequences and is predominately propylene. The resultant blends manifest unexpected compatibility characteristics, increased tensile strength, and improved process characteristics, e.g., a single melting point.

1 - 31 . (canceled)  
     
     
         32 . An article of manufacture made from a polymer blend comprising at least one polymer (A) and at least one polymer (B), polymer (A) comprising about 5 to about 99 weight percent of the blend, and polymer (A) comprising a copolymer of about 94.2 to about 88.4 weight percent of units derived from propylene, and about 5.8 to about 11.6 weight percent of units derived from ethylene, and polymer (A) is further characterized as having a DSC curve with a T me  that remains essentially the same and a T max  that decreases as the amount of comonomer in the copolymer is increased; and polymer (B) comprising a thermoplastic polymer other than polymer (A).  
     
     
         33 . The article of  claim 32  in the form of a film.