US 12,377,592 B2
Use of metallocene based polypropylene random copolymers in blown films
Leonardo Cortes, League City, TX (US)
Assigned to Fina Technology, Inc., Houston, TX (US)
Filed by FINA TECHNOLOGY, INC., Houston, TX (US)
Filed on Nov. 14, 2016, as Appl. No. 15/350,550.
Prior Publication US 2018/0133945 A1, May 17, 2018
Int. Cl. B29C 48/00 (2019.01); B29C 48/08 (2019.01); B29C 48/10 (2019.01); B29C 48/21 (2019.01); B32B 27/08 (2006.01); B32B 27/32 (2006.01); B29K 23/00 (2006.01); B29K 79/00 (2006.01); B29K 105/00 (2006.01); B29L 31/00 (2006.01)
CPC B29C 48/022 (2019.02) [B29C 48/0018 (2019.02); B29C 48/08 (2019.02); B29C 48/10 (2019.02); B29C 48/21 (2019.02); B32B 27/08 (2013.01); B32B 27/327 (2013.01); B29K 2023/14 (2013.01); B29K 2079/085 (2013.01); B29K 2105/0005 (2013.01); B29K 2105/0094 (2013.01); B29K 2995/0022 (2013.01); B29K 2995/0026 (2013.01); B29K 2995/0077 (2013.01); B29K 2995/0081 (2013.01); B29K 2995/0097 (2013.01); B29L 2031/7128 (2013.01); B32B 2307/406 (2013.01); B32B 2307/412 (2013.01); B32B 2307/54 (2013.01); B32B 2307/5825 (2013.01); B32B 2307/732 (2013.01); B32B 2439/06 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A coextruded multi-layer blown film comprising:
a core layer, wherein the core layer comprises a metallocene polyethylene polymer;
and at least one first skin layer, wherein the at least one first skin layer comprises an isotactic metallocene-based polypropylene random copolymer, and at least one second skin layer, wherein the at least one second skin layer comprises a blend of the isotactic metallocene-based polypropylene random copolymer with at least one other polymer formed via Ziegler-Natta catalyst, selected from the group consisting of low density polyethylenes, high density polyethylenes, ethylene copolymers, polypropylene homopolymers, polypropylene random copolymers, polybutenes, terpolymers, and combinations thereof, wherein the isotactic metallocene-based polypropylene random copolymer comprises a melting temperature less than or equal to 140° C., and
wherein the co-extruded multi-layer blown film has a haze of less than 15%, a gloss of greater than 50, an Elmendorf tear in the machine direction of at least 300 g, an Elmendorf tear in the transverse direction of at least 1000 g, a tensile strength at yield in the machine direction of greater than 3075 psi, a secant modulus of greater than 50 kpsi, and a seal initiation temperature @0.77 N/cm, of less than 104° C.