Substrate for a label laminate, a label laminate and a method for manufacturing a label laminate

Patent metadata

Field	Value
Publication number	US-10293587-B2
Application number	US-201315032827-A
Country	US
Kind code	B2
Filing date	Nov 6, 2013
Priority date	Nov 6, 2013
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

The invention relates to a label laminate and a release liner of the label laminate. According to an embodiment release liner comprises a substrate comprising propylene block copolymer. The substrate may be oriented in a machine direction of the substrate. The substrate may have an elongation of the substrate in a machine direction of the substrate is less than 3% at a tension level between 200 and 1200 N/m. The substrate may have a ratio of 1% secant modulus in machine direction of the substrate to elongation in transverse direction of the substrate is between 2 and 15. Further the invention relates to a use of a release liner for self-adhesive label laminate and to a method for providing a label laminate.

First claim

The invention claimed is:

1. A release liner for a label laminate, wherein the release liner comprises a substrate having a multilayer structure comprising at least a core layer, a first skin layer and a second skin layer, and wherein each of the layers comprise at least 38 weight percent propylene block copolymer and at most 60weight percent of at least one of propylene homopolymer and propylene random copolymer,
wherein the substrate is uniaxially oriented in a machine direction of the substrate.

2. A release liner according to claim 1 , wherein an elongation of the substrate in the machine direction is less than 3% at a tension level between 200and 1200 N/m.

3. A release liner according to claim 1 , wherein a ratio of 1% secant modulus in machine direction of the substrate to elongation in transverse direction of the substrate is between 2 and 15.

4. A release liner according to claim 1 , wherein an amount of propylene block copolymer is at least 68 wt. %.

5. A release liner according to claim 1 , wherein a release layer is arranged onto one surface of the substrate.

6. A release liner according to claim 1 , wherein an amount of propylene homopolymer and/or propylene random copolymer is at most 30 wt. %.

7. A release liner according to claim 1 , wherein the substrate further comprises between 0.01 and 0.05 wt. % of a nucleating agent.

8. A release liner according to claim 1 , wherein an amount of olefin based polymer(s) other than polypropylene is less than 10 wt. %, preferably less than 5 wt. %, more preferably less than 2 wt. %.

9. A release liner according to claim 1 , wherein the skin layer(s) further comprise anti-blocking agent.

10. A release liner according to claim 1 , wherein the substrate comprises an orientation degree in the machine direction of the substrate between 5 and 10, preferably between 6 and 9.

11. A release liner according to claim 1 , wherein total thickness of the substrate is between 10 and 60 microns, preferably between 15 and 40microns, more preferably between 20 and 30 microns.

12. A release liner according to claim 1 , wherein the oriented substrate has a shrinkage less than 5%, preferably less than 2%, or more preferably less than 1% at temperatures below 30 degrees C.

13. A label laminate comprising a face stock, a release liner and an adhesive layer between the face stock and the release liner, wherein the release liner comprises a substrate having a multilayer structure comprising at least a core layer, a first skin layer and a second skin layer, and wherein each of the layers comprise at least 38 weight percent propylene block copolymer and at most 60 weight percent of at least one of propylene homopolymer and propylene random copolymer,
wherein the substrate is uniaxially oriented in a machine direction of the substrate.

14. A label laminate according to claim 13 , wherein
an elongation of the substrate in a machine direction of the substrate is less than 3% at a tension level between 200 and 1200 N/m.

15. A label laminate according to claim 13 , wherein
a ratio of 1% secant modulus in machine direction of the substrate to elongation in transverse direction of the substrate is between 2 and 15.

16. A label laminate according to claim 13 , wherein an amount of propylene block copolymer is at least 68 wt. %.

17. A label laminate according to claim 13 , wherein a release layer is arranged between the adhesive layer and the substrate of the release liner.

18. A label laminate according to claim 13 , wherein an amount of propylene homopolymer and/or propylene random copolymer is at most 30wt. %.

19. A label laminate according to claim 13 , wherein the substrate further comprises between 0.01 and 0.05 wt. % of a nucleating agent.

20. A label laminate according to claim 13 , wherein an amount of olefin based polymer(s) other than polypropylene is less than 10 wt. %, preferably less than 5 wt. %, more preferably less than 2 wt. %.

21. A label laminate according to claim 13 , wherein the skin layer(s) further comprise anti-blocking agent.

22. A label laminate according to claim 13 , wherein the substrate comprises an orientation degree in the machine direction of the substrate between 5 and 10, preferably between 6 and 9.

23. A label laminate according to claim 13 , wherein total thickness of the substrate is between 10 and 60 microns, preferably between 15 and 40 microns, more preferably between 20 and 30 microns.

24. A label laminate according to claim 13 , wherein the oriented substrate has a shrinkage less than 5%, preferably less than 2%, or more preferably less than 1% at temperatures below 30 degrees C.

25. A label laminate according to claim 13 , wherein the label laminate is self-adhesive in which the adhesive layer comprises pressure sensitive adhesive.

26. A method for providing a label laminate according to claim 13 , the method comprising:
forming a substrate by melt processing technique;
stretching the substrate uniaxially in a machine direction of the substrate for providing a machine direction oriented substrate;
coating one surface of the machine direction oriented substrate with a release agent layer for providing a release liner;
applying an adhesive layer over the release agent layer and/or over a face material layer; and
laminating the release liner with the face material layer for providing the label laminate having the adhesive layer in between the release liner and the face material wherein the substrate having a multilayer structure comprising at least a core layer.

27. A method according to claim 26 , wherein the method further comprises cooling of the machine direction oriented substrate to an ambient temperature right after the stretching for providing a non-annealed substrate.

28. A method according to claim 26 , wherein the method further comprises:
annealing of the machine direction oriented substrate after the stretching for providing an annealed substrate; and
subsequently cooling the annealed substrate to an ambient temperature.

Assignees

• Upm Raflatac Oy

Inventors

• Mitchell Noel
• Manner Matti
• Saxberg Tom

Classifications

• B32B37/12

  characterised by using adhesives · CPC title

• C09J2203/334

  as a label · CPC title

• C09J7/405

  characterised by the substrate of the release liner · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• C09J2201/606

  Chemistry & Metallurgy · mapped topic