Multilayer film for label and a method for providing such

Patent metadata

Field	Value
Publication number	US-2016136935-A1
Application number	US-201314902408-A
Country	US
Kind code	A1
Filing date	Jul 12, 2013
Priority date	Jul 12, 2013
Publication date	May 19, 2016
Grant date	—

Abstract

The invention relates to providing a method for obtaining a multilayer film for thermally inducible shrink labels, products thereof and use of such products.

First claim

1 . A multilayer film for labeling comprising a first skin layer, a second skin layer and a core layer between the first skin layer and the second skin layer, wherein at least one of the first skin layer and the second skin layer comprises cyclic olefin copolymer and the core layer comprises propylene terpolymer and copolymer of ethylene and butyl acrylate.

2 . The multilayer film according to claim 1 , wherein the core layer comprises copolymer of ethylene and butyl acrylate equal to or more than 90% by weight, preferably equal to or more than 95% by weight, most preferably equal to or more than 98% by weight.

3 . The multilayer film according to claim 1 , wherein the copolymer of ethylene and butyl acrylate is a block or random copolymer, comprising a n-butyl acrylate content in the range of 5% to 30% by weight.

4 . The multilayer film according to claim 1 , wherein the core layer comprises propylene terpolymer in the range of 20 to 80% by weight, preferably in the range of 25 to 75% by weight, most preferably in the range of 30 to 70% by weight.

5 - 7 . (canceled)

8 . The multilayer film according to claim 1 , wherein the core layer further comprises cyclic olefin copolymer equal to or less than 15% by weight, preferably in the range of 0.01 to 15% by weight, most preferably in the range of 1 to 10% by weight.

9 . The multilayer film according to claim 1 , wherein at least one of the first skin layer and the second skin layer or the core layer further comprises polyolefin elastomer.

10 . The multilayer film according to claim 1 , wherein at least one of the first skin layer and the second skin layer comprises cyclic olefin copolymer equal to or more than 90% by weight, preferably equal to or more than 95% by weight, most preferably equal to or more than 98% by weight or wherein at least one of the first skin layer and the second skin layer comprises linear low density polyethylene equal to or less than 30% by weight, preferably equal to or less than 10% by weight.

11 - 12 . (canceled)

13 . The multilayer film according to the claim 10 , wherein the linear low density polyethylene is a copolymer of ethylene and 1-octene having a melting temperature in the range of 120 to 125° C., preferably in the range of 122 to 124° C. and/or a melt index of 1.9 to 2.1, preferably in the range of 2.0 to 2.1.

14 - 15 . (canceled)

16 . The multilayer film according to claim 1 , wherein the multilayer film is configured to shrink in the direction of the orientation of the multilayer film at least 15%, preferably at least 25%, or preferably at least 35% at a temperature range between 65 and 85° C.

17 . The multilayer film according to claim 1 , wherein the multilayer film is configured to shrink less than 10% at a temperature below 65° C.

18 - 30 . (canceled)

31 . The multilayer film according to claim 1 , the multilayer film comprising a surface tension level on the first surface of the skin layer higher than or equal to 38 mN/m.

32 . The multilayer film according to claim 1 , wherein a thickness of the first skin layer and the second skin layer is equal to or less than 20%, preferably equal to or less than 10%, most preferably equal to or less than 5% of a thickness of the multilayer film.

33 - 34 . (canceled)

35 . The multilayer film according to claim 1 , comprising an average thickness in the range of 20 to 60 micrometers after monoaxially stretched in the range of 4 to 7 times and slitted.

36 - 37 . (canceled)

38 . The multilayer film according to claim 1 , comprising a shrink force in the orientation direction of the face film during heating at temperatures between 60 and 98° C. of less than 10N/15 mm, or less than 8N/15 mm, or in the range of 1 to 10N/15 mm, or in the range of 2 to 8 N/15 mm.

39 . A label comprising a length, a width and a thickness dimension, the label derived from the multilayer film according to claim 1 .

40 - 53 . (canceled)

54 . A method for obtaining a multilayer film for thermally inducible shrink labels, the method comprising:
providing a first skin layer and a second skin layer, wherein at least one of the first skin layer and the second skin layer comprises cyclic olefin copolymer, providing a core layer between the first and the second skin layer, wherein the core layer comprises propylene terpolymer and copolymer of ethylene and butyl acrylate, stretching the multilayer film in the range of 4 to 7 times in a first direction for obtaining monoaxially stretched multilayer film having a tension in the first direction, and cooling the multilayer film to room temperature.

55 . The method according to claim 54 , wherein the multilayer film is configured to shrink in the direction of the orientation of the multilayer film at least 15%, preferably at least 25%, or preferably at least 35% at a temperature range between 65 and 85° C.

56 . The method according to claim 54 , further comprising
providing a surface treatment for the multilayer film surface for increasing the surface tension of the first skin layer or the second skin layer.

57 . The method according to claim 54 , wherein the first skin layer and the second skin layer have been provided by extrusion or casting.

58 . The method according to claim 54 , wherein the first direction is parallel or perpendicular to the multilayer film machine direction.

59 . (canceled)

Assignees

• Upm Raflatac Oy

Inventors

• Mitchell Noel
• Manner Matti

Classifications

• B32B2307/51

  Elastic · CPC title

• B32B2307/516

  mono-axially · CPC title

• B32B27/327

  comprising polyolefins obtained by a metallocene or single-site catalyst · CPC title

• B32B27/308

  comprising acrylic (co)polymers · CPC title

• C08K2201/015

  Additives for heat shrinkable compositions · CPC title