Polypropylene blends for non-woven production
View Patent ↗Polypropylene resin compositions are provided that are useful in the production of thermoformed articles and biaxially oriented polypropylene films (BOPPs), tapes and fibers. The resins of the present invention are blends of high crystalline (low solubles) polypropylene homopolymer and an ethylene/propylene random copolymer (RCP). These blends can be used to replace standard high solubles BOPP grade polypropylene homopolymers. In addition, the use of high crystalline polypropylene homopolymers in the blends imparts improved stiffness to the finished films while maintaining good processability of the blends. Such polypropylene compositions are effectively produced by in-reactor blending of a high crystalline propylene homopolymer and a propylene/ethylene random copolymer.
1. A non-woven fabric comprising at least one layer of fibers including a reactor blended polypropylene copolymer, the polypropylene copolymer comprising about 70% to about 95% by weight of a polypropylene homopolymer, said polypropylene homopolymer having less than 3% by weight xylene solubles and a crystallinity of at least 55%; and about 5% to about 30% by weight of an ethylene/propylene copolymer, said ethylene/propylene copolymer containing from about 0.5% to about 15% ethylene by weight, wherein the at least one layer of fibers is a spunbond or a meltblown fabric layer.
2. The non-woven fabric according to claim 1 , wherein the polypropylene copolymer comprises about 70% to about 85% by weight of the propylene homopolymer, and about 15% to about 30% by weight of the ethylene/propylene copolymer.
3. The non-woven fabric according to claim 2 , wherein the polypropylene copolymer comprises about 82% to about 88% by weight of the polypropylene homopolymer and about 12% to about 18% of the ethylene/propylene random copolymer, and the ethylene/propylene random copolymer has an ethylene content of from 2% to 4% by weight.
4. The non-woven fabric according to claim 2 , wherein the ethylene/propylene random copolymer contains from about 2.0% to about 4.0% ethylene by weight.
5. A non-woven fabric comprising at least one layer of fibers including a reactor blended polypropylene copolymer, the polypropylene copolymer comprising about 70% to about 95% by weight of a polypropylene homopolymer, said polypropylene homopolymer having less than 3% by weight xylene solubles and a crystallinity of at least 55%; and about 5% to about 30% by weight of an ethylene/propylene copolymer, said ethylene/propylene copolymer containing from about 0.5% to about 7.0% ethylene by weight, wherein the at least one layer of fibers is a spunbond fabric layer.
6. The non-woven fabric according to claim 5 , wherein the polypropylene copolymer comprises about 70% to about 85% by weight of the propylene homopolymer, and about 15% to about 30% by weight of the ethylene/propylene copolymer.
7. The non-woven fabric according to claim 6 , wherein the polypropylene copolymer comprises about 82% to about 88% by weight of the polypropylene homopolymer and about 12% to about 18% of the ethylene/propylene random copolymer, and the ethylene/propylene random copolymer has an ethylene content of from 2% to 4% by weight.
8. The non-woven fabric according to claim 5 , wherein the ethylene/propylene random copolymer contains from about 2.0% to about 4.0% ethylene by weight.
9. A non-woven fabric comprising at least one layer of fibers including a reactor blended polypropylene copolymer, the polypropylene copolymer comprising about 70% to about 95% by weight of a polypropylene homopolymer, said polypropylene homopolymer having less than 3% by weight xylene solubles and a crystallinity of at least 55%; and about 5% to about 30% by weight of an ethylene/propylene copolymer, said ethylene/propylene copolymer containing from about 0.5% to about 7.0% ethylene by weight, wherein the at least one layer of fibers is a meltblown fabric layer.
10. The non-woven fabric according to claim 9 , wherein the polypropylene copolymer comprises about 70% to about 85% by weight of the propylene homopolymer, and about 15% to about 30% by weight of the ethylene/propylene copolymer.
11. The non-woven fabric according to claim 10 , wherein the polypropylene copolymer comprises about 82% to about 88% by weight of the polypropylene homopolymer and about 12% to about 18% of the ethylene/propylene random copolymer, and the ethylene/propylene random copolymer has an ethylene content of from 2% to 4% by weight.
12. The non-woven fabric according to claim 9 , wherein the ethylene/propylene random copolymer contains from about 2.0% to about 4.0% ethylene by weight.
13. The non-woven fabric according to claim 1 , wherein the ethylene/propylene copolymer contains from about 7.0 to about 15% ethylene by weight.