Polyolefin Film for Use in Packaging

Patent metadata

Field	Value
Publication number	US-2016122484-A1
Application number	US-201414895231-A
Country	US
Kind code	A1
Filing date	Jun 6, 2014
Priority date	Jun 12, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

A polyolefin packaging film is provided. The polyolefin film is formed by a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and nanoinclusion additive is provided. The nanoinclusion additive is dispersed within the continuous phase as discrete nano-scale phase domains. When drawn, the nano-scale phase domains are able to interact with the matrix in a unique manner to create a network of nanopores.

First claim

1 - 38 . (canceled)

39 . A film comprising a thermoplastic composition, wherein the composition contains a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains, wherein a porous network is defined in the composition that includes a plurality of nanopores having an average cross-sectional dimension of about 800 nanometers or less.

40 . The film of claim 39 , wherein the nanopores have an average cross-sectional dimension of from about 5 to about 700 nanometers.

41 . The film of claim 39 , wherein the nanopores have an average axial dimension of from about 100 to about 5000 nanometers.

42 . The film of claim 39 , wherein the polyolefin matrix polymer has a melt flow rate of from about 0.5 to about 80 grams per 10 minutes, determined at a load of 2160 grams and at 230° C. in accordance with ASTM D1238.

43 . The film of claim 39 , wherein the polyolefin matrix polymer is a propylene homopolymer, propylene/α-olefin copolymer, ethylene/α-olefin copolymer, or a combination thereof.

44 . The film of claim 39 , wherein the polyolefin matrix polymer is a substantially isotactic polypropylene homopolymer or a copolymer containing at least about 90% by weight propylene.

45 . The film of claim 39 , wherein the continuous phase constitutes from about 60 wt. % to about 99 wt. % of the thermoplastic composition.

46 . The film of claim 39 , wherein the nanoinclusion additive includes a functionalized polyolefin.

47 . The film of claim 46 , wherein the functionalized polyolefin is a polyepoxide.

48 . The film of claim 39 , wherein the nanoinclusion additive has melt flow rate of from about 0.1 to about 100 grams per 10 minutes, determined at a load of 2160 grams and at a temperature at least about 40° C. above the melting temperature in accordance with ASTM D1238.

49 . The film of claim 48 , wherein the ratio of the melt flow rate of the polyolefin matrix polymer to the melt flow rate of the nanoinclusion additive is from about 0.2 to about 8.

50 . The film of claim 39 , wherein the nanoinclusion additive is in the form of nano-scale domains, wherein the nano-scale domains have an average cross-sectional dimension of from about 1 nanometer to about 1000 nanometers.

51 . The film of claim 39 , wherein the nanoinclusion additive constitutes from about 0.05 wt. % to about 20 wt. % of the composition, based on the weight of the continuous phase.

52 . The film of claim 39 , wherein the composition further comprises a microinclusion additive dispersed within the continuous phase in the form of discrete domains.

53 . The film of claim 52 , wherein the microinclusion additive is a polymer that includes a styrenic copolymer, fluoropolymer, polyvinyl alcohol, polyvinyl acetate, or polyester.

54 . The film of claim 52 , wherein the polymer of the microinclusion additive is polylactic acid.

55 . The film of claim 52 , wherein the microinclusion additive is in the form of micro-scale domains having an average axial dimension of from about 1 micrometer to about 400 micrometers.

56 . The film of claim 52 , wherein the microinclusion additive constitutes from about 1 wt. % to about 30 wt. % of the composition, based on the weight of the continuous phase.

57 . The film of claim 39 , wherein the thermoplastic composition further comprises an interphase modifier.

58 . The film of claim 39 , wherein the porous network further includes micropores.

59 . The film of claim 39 , wherein the total pore volume of the composition is from about 15% to about 80% per cubic centimeter.

60 . The film of claim 39 , wherein nanopores constitute about 20 vol. % or more of the total pore volume of the composition.

61 . The film of claim 39 , wherein the thermoplastic composition has a density of about 0.90 g/cm 3 or less.

62 . The film of claim 39 , wherein the film has a water vapor transmission rate of about 300 g/m 2 /24 hours or more.

63 . The film of claim 39 , wherein the film is a multi-layered film that contains a core layer and at least one outer layer, wherein the core layer, the outer layer, or both contain the thermoplastic composition.

Assignees

• Kimberly Clark Co

Inventors

• Topolkaraev Vasily A
• Mceneany Ryan J
• Mleziva Mark M
• Thompson Brent M

Classifications

• B32B2264/0278

  Polyester particles · CPC title

• C08L23/12

  Polypropene · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• B29K2063/00

  Use of {EP, i.e.} epoxy resins {or derivatives thereof}, as moulding material · CPC title

• C08J2323/08

  Copolymers of ethene (C08J2323/16 takes precedence) · CPC title