Machine direction oriented film for labels

Patent metadata

Field	Value
Publication number	US-2016229158-A1
Application number	US-201415022671-A
Country	US
Kind code	A1
Filing date	Oct 8, 2014
Priority date	Oct 11, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

Machine direction oriented multilayer film suitable for preparing labels, comprising a core layer of a bimodal terpolymer and two outer layers comprising HDPE.

First claim

1 . A machine direction oriented multilayer film suitable for labels comprising a core layer (C) and two outer layers (O- 1 , O- 2 ) sandwiching the core layer, wherein (i) the core layer (C) comprises a bimodal ethylene/1-butene/C 6 -C 12 -alpha-olefin terpolymer, with a density between 926 kg/m 3 to 950 kg/m 3 and (ii) the two outer layers comprising unimodal HDPE with a density of more than 940 kg/m 3 up to 970 kg/m 3 .

2 . The multilayer film according to claim 1 , whereby the film is in the form of a stretched film which is uniaxially oriented in the machine direction (MD) in a draw ratio of 1:4 to 1:12.

3 . The multilayer film according to claim 1 , wherein the machine direction oriented film has a final thickness of at least 25 μm up to 85 μm.

4 . The multilayer film according to claim 1 , wherein the core layer (C) comprises a bimodal ethylene/1-butene/C6-C12-alpha-olefin terpolymer, which comprises
(A-1) a lower molecular weight component being a homopolymer of ethylene and (A-2) a higher molecular weight component being a terpolymer of ethylene, 1-butene and a C 6 -C 12 -alpha-olefin.

5 . The multilayer film according to claim 1 , wherein the C 6 -C 12 -alpha-olefin is selected from the group of 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene.

6 . The multilayer film according to claim 1 , wherein the ethylene/1-butene/C 6 -C 12 -alpha-olefin terpolymer comprises a lower molecular weight component being a homopolymer of ethylene and a higher molecular weight component being a terpolymer of ethylene, 1-butene and a C 6 -C 12 -alpha-olefin,
the bimodal terpolymer having a melt flow rate MFR 2 according to ISO 1133 (190° C., 2.16 kg) of 0.01 to 6 g/10 min, a melt flow rate MFR 5 according to ISO 1133 (190° C., 5 kg) of 0.1 to 20 g/10 min, a density according to ISO 1183, (method A) of 926 to 950 kg/m 3 , and an overall comonomer content of 0.3 to 7% by mol, wherein the lower molecular weight component of the bimodal terpolymer has a melt index MFR 2 according to ISO 1133 (190° C.; 2.16 kg) of 50 to 3 200 g/10 min, a density according to ISO 1183, (method A) of 930 to 980 kg/m 3 , and the amount of the lower molecular weight component in the bimodal terpolymer is in the range of 30 to 70 wt %.

7 . The multilayer film according to claim 1 , wherein the outer layers (O- 1 , O- 2 ) comprises a unimodal high density polyethylene with a MFR2 according to ISO 1133 (190° C.; 2.16 kg)) of 0.05 to 10 g/10 min, a density according to ISO 1183, (method A) of 941-970 kg/m3 and an MWD between 2 to 20.

8 . The multilayer film according to claim 1 , wherein the core layer and/or the outer layers can contain antioxidants, process stabilizers, polymer processing agents, pigments; UV-stabilizers, clay, talc, calcium carbonate, calcium stearate, zinc stearate and antistatic additives in the form of single components or as part of a masterbatch.

9 . The multilayer film according to claim 8 , wherein the core layer contains a pigment as part of a masterbatch.

10 . The multilayer film according to claim 1 , having a original thickness before being machine direction oriented of 100 to 400 μm.

11 . The multilayer film according to claim 1 , wherein the outer layers and core layer are all of equal thickness or alternatively each outer layer forms 10 to 35% of the total final thickness of the multilayered film and the core layer forms 30 to 80% of the total final thickness of the multilayered film.

12 . A process for producing a multilayer film according to claim 1 , wherein the multilayer film is first formed by a blown film coextrusion process with subsequent uniaxial orientation in machine direction.

13 . The process according to claim 12 , wherein the blown film coextrusion process is performed either on a 3-layer coextrusion line or on a 5- or 7-layer coextrusion line, where the central dies all extrude B-layer material to form an ABBBA or ABBBBBA type film or each of the two, respectively three outer dies extrude A-layer material to form an AABAA or AAABAAA type film or as a combination of the before described possibilities an AABBBAA type film is produced, whereby the so produced films are still ABA films as all A- respectively B-layers are identical.

14 - 16 . (canceled)

17 . A label comprising the multilayer structure according to claim 1 .

18 . The label according to claim 17 , which is a pressure sensitive label, a linerless label, or a heat shrink sleeve label.

Assignees

• Borealis Ag

Inventors

• Cavacas Paulo
• Schuster Gerhard

Classifications

• B29C55/06

  parallel with the direction of feed · CPC title

• B32B2307/516

  mono-axially · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B2250/40

  Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA · CPC title

• B29C47/065

  Operations & Transport · mapped topic