Clarified Polypropylene and Ethylene Alpha Olefin Blend
The present disclosure is directed to polymeric compositions and methods for making the same. The polymeric composition includes a clarified polypropylene and a plurality of ethylene and alpha-olefin copolymers. The polymeric composition has low haze and exhibits increased impact strength when compared to clarified polypropylene.
1 . A polymeric composition comprising:
a clarified polypropylene;
a first ethylene and alpha-olefin copolymer having a density greater than the density of the clarified polypropylene; and
a second ethylene and alpha-olefin copolymer having a density less than the density of the clarified polypropylene.
2 . (canceled)
3 . The polymeric composition of claim 1 wherein the clarified polypropylene has a refractive index and at least one of the ethylene and alpha-olefin copolymers has a refractive index within about ±0.005 of the clarified polypropylene copolymer refractive index.
4 . The polymeric composition of claim 1 wherein the first ethylene and alpha-olefin copolymer and the second ethylene and alpha-olefin copolymer have an average density, and the average density is within from about 0.5% to about 3% of the density value for the clarified polypropylene.
5 . The polymeric composition of claim 1 comprising from about 1 wt % to about 75 wt % total ethylene and alpha-olefin copolymer content.
6 . A polymeric composition comprising:
a clarified random propylene copolymer;
a first ethylene and alpha-olefin copolymer having a density greater than the density of the clarified polypropylene; and
a second ethylene and alpha-olefin copolymer having a density less than the density of the clarified polypropylene.
7 . (canceled)
8 . The polymeric composition of claim 6 wherein the first ethylene and alpha-olefin copolymer has a density greater than about 0.90 g/cc and the second ethylene and alpha-olefin copolymer has a density less than about 0.90 g/cc.
9 . The polymeric composition of claim 6 wherein at least one of the ethylene and alpha-olefin copolymers is a substantially linear ethylene and alpha-olefin copolymer.
10 . The polymeric composition of claim 6 wherein the total ethylene and alpha-olefin content is from about 5 wt % to about 45 wt % of the polymeric composition.
11 . The polymeric composition of claim 6 wherein the weight ratio of the first ethylene and alpha-olefin copolymer to the second ethylene alpha-olefin copolymer is from 0.2:1 to 5:1.
12 . The polymeric composition of claim 6 comprising an equal amount of the first ethylene and alpha-olefin copolymer and the second ethylene and alpha-olefin copolymer.
13 . The polymeric composition of claim 6 wherein the polymeric composition has a haze value from about 10% to about 20%.
14 . The polymeric composition of claim 6 wherein the polymeric composition has an Izod impact strength at 0° C. from about 5 ft-lb/in to about 15 ft-lb/in.
15 . A method for producing a polymeric composition comprising:
selecting a first ethylene and alpha-olefin copolymer having a density greater than or equal to the density of a clarified polypropylene;
selecting a second ethylene and alpha-olefin copolymer having a density less than the clarified propylene density; and
mixing the first ethylene and alpha-olefin copolymer and the second ethylene and alpha-olefin copolymer with the clarified polypropylene to form a polymeric composition having a haze value from 10% to 20%.
16 . The method of claim 15 comprising choosing the first ethylene and alpha-olefin copolymer and the second ethylene and alpha-olefin copolymer so that their average density is within 0.5% to 3% of the clarified propylene density.
17 . The method of claim 15 comprising choosing at least one ethylene and alpha-olefin copolymer with a refractive index within about ±0.005 of the clarified polypropylene refractive index.
18 . The method of claim 16 comprising forming a polymeric composition having a haze value from about 10% to about 20% and an Izod impact strength at 0° C. from about 5 ft-lb/in to about 15 ft-lb/in.
19 - 20 . (canceled)
21 . The polymeric composition of claim 1 wherein the polymeric composition has a haze value from about 10% to about 20%.
22 . The polymeric composition of claim 1 wherein the clarified polypropylene has a density of 0.90 g/cc.
23 . The polymeric composition of claim 1 wherein the clarified polypropylene has a melt flow rate of 10 g/10 min.
24 . The polymeric composition of claim 6 wherein the clarified random propylene copolymer has a density of 0.90 g/cc and a melt flow rate of 10 g/10 min.