Patent ID: 8710148
Filing Date: 2014-04-29
Classification: A61L,C08F,C08L,D04H,Y10T

Abstract:
1. A propylene-based polymer composition comprising propylene and from about 5 wt % to about 20 wt % ethylene and/or a C 4 -C 12 alpha-olefin, wherein the polymer composition has a triad tacticity greater than about 90%, a heat of fusion less than about 75 J/g, and an MFR greater than or equal to about 25 g/10 min (230° C., 2.16 kg); the polymer composition is a reactor grade composition comprising a reactor blend of a first polymer and a second polymer; the first and second polymers are prepared with the same catalyst system; and the polymer composition has at least one of (a) a Die C tear strength greater than or equal to about 195 lbf/in, and (b) a force required to break apart two or more pellets formed from the polymer composition and stored under a load at 50° C. for one week of less than about 20 N, based on the storage stability test, where the storage stability test entails placing 35 grams of pellets of the polymer composition into a 50 ml glass beaker having a diameter of about 40 mm where the bottom of the beaker is covered with a film of Teflon-coated woven glass fabric and the walls covered with a polyester film, where the top layer of the pellets is also covered with a film of Teflon-coated woven glass fabric, and where the beaker is then stored inside an air-ventilated oven at 50° C. for one week with a 1160 g weight applied on top of the pellets, and where at the end of one week the beaker is removed from the oven and the sample allowed to cool to room temperature, if the sample is agglomerated or aggregated at the end of the storage, it is removed from the beaker and placed (with the cylinder sections perpendicular) between the plates of a tensile machine operated in compression mode with a compression speed of 50 mm/min, which measures the force required to break the cylinder, if the pellets are free flowing at the end of the storage test the force required to break apart the pellets is zero.