PRESSURE-SENSITIVE ADHESIVE STRIP FOR MOISTURE-INSENSITIVE PEELABLE ADHESIVE BONDS

• US 20110220295A1
• Filed: 08/10/2007
• Published: 09/15/2011
• Est. Priority Date: 08/18/2006
• Status: Abandoned Application

• Current Assignee: Tesa SE (maxingvest GmbH & Co. KGaA)
• Original Assignee: Tesa SE (maxingvest GmbH & Co. KGaA)
• Inventors: Junghans, Andreas, Krawinkel, Thorsten
• Application Number:
  US12/377,555
• Publication Number:
  US 20110220295A1
• Time in Patent Office: Days
• US Class Current: 156/709
• CPC Class Codes: B32B 43/006 Delaminating
• CPC Class Codes: B32B 5/04 characterised by a layer being specifically extensible by reason of its structure or arrangement , e.g. by reason of the chemical nature of the fibres or filaments
• CPC Class Codes: C09J 153/02 Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C09J 183/04 Polysiloxanes
• CPC Class Codes: C09J 2301/1242 the opposite adhesive layers being different
• CPC Class Codes: C09J 2301/162 the carrier being a laminate constituted by plastic layers only
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2301/304 the adhesive being heat-activatable, i.e. not tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2301/308 the adhesive tape or sheet losing adhesive strength when being stretched, e.g. stretch adhesive
• CPC Class Codes: C09J 2400/243 in the substrate
• CPC Class Codes: C09J 2423/105 in the release coating
• CPC Class Codes: C09J 2453/00 Presence of block copolymer
• CPC Class Codes: C09J 2467/006 in the substrate
• CPC Class Codes: C09J 2483/00 Presence of polysiloxane
• CPC Class Codes: C09J 7/26 Porous or cellular plastics
• CPC Class Codes: C09J 7/29 Laminated material metallised plastics C09J7/22
• CPC Class Codes: C09J 7/381 based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09J 7/387 Block-copolymers
• CPC Class Codes: Y10T 156/1142 Changing dimension during delaminating [e.g., crushing, expanding, warping, etc.]
• CPC Class Codes: Y10T 428/249983 As outermost component
• CPC Class Codes: Y10T 428/2848 : Three or more layers

Abstract

The invention relates to a peelable adhesive strip which is coated with a pressure-sensitive adhesive at least one side. Said adhesive strip is constituted of the following layers: a core layer having an elongation at tear of at least 300%, an external carrier layer having an elongation at tear of not more than 120% and at least some sections of which are connected to the core layer in such a manner that it becomes detached from the core layer when the same is stretched, a first adhesive layer at least some sections of which are applied to the side of the external carrier layer and which is opposite the side connected to the core layer.

Claims

1. A redetachable, at least single-sided pressure-sensitive adhesive strip comprising:

a) a core layer which has a breaking extension of at least 300%,

b) an outer carrier layer which has a breaking extension of not more than 120% and which at least sectionally is connected to the core layer such that it separates from the core layer when the latter is extensionally stretched, and

c) a first adhesive layer which is applied at least sectionally to the side of the outer carrier layer that is opposite the side connected to the core layer.

2. The adhesive strip of claim 1, wherein the core layer is formed from an adhesive which is redetachable by extensional stretching in the bond plane.

3. The adhesive strip of claim 1, wherein the core layer protrudes beyond the outer carrier layer at least in one region.

4. The adhesive strip of claim 3, wherein the protruding region is made nontacky.

5. The adhesive strip of claim 1, wherein the adhesive of the core layer is constructed on the basis of styrene block copolymers.

6. The adhesive strip of claim 1, wherein the core layer is formed by a carrier which is redetachable by extensional stretching in the bond plane.

7. The adhesive strip of claim 1, wherein a further adhesive layer is applied sectionally on a side of the carrier that is opposite the side connected to the outer carrier layer.

8. The adhesive strip of claim 6, wherein between carrier and outer carrier layer there is a second adhesive layer.

9. The adhesive strip of claim 8, wherein the bond strengths of the second adhesive layer and of the further adhesive layer can be reduced by extensional stretching in the bond plane.

10. The adhesive strip of at least one of claims 6 to 9, wherein the carrier protrudes beyond the outer carrier layer at least in one region.

11. The adhesive strip of claim 6, wherein the carrier foam.

12. The adhesive strip of claim 1, wherein the first adhesive layer is based on silicone and is crosslinked.

13. The adhesive strip of claim 1, wherein on the core layer and/or on the further adhesive layer there is, at least sectionally, a second outer carrier layer which separates from the core layer or from the further adhesive layer when the latter is extensionally stretched, and which is provided at least sectionally on the free side with a third adhesive layer.

14. The adhesive strip of claim 13, wherein the outer carrier layer and the second outer carrier layer and/or the first and the third adhesive layers are identical.

15. The adhesive strip of claim 1, wherein the adhesive of the core layer, the further adhesive and/or the third adhesive are composed of block copolymers or of a mixture thereof, especially including polymer blocks formed from vinyl aromatics (A blocks) and those formed by polymerization of 1,3-dienes (B blocks).

16. The adhesive strip of claim 15, wherein the vinyl aromatics are styrene and/or the B blocks are formed by polymerization of butadiene and/or isoprene and/or their hydrogenation products or by polymerization of isobutylene.

18. A method of separating two substrates bonded with the adhesive strip of claim 1 comprising stretching the core layer in the direction of the bond plane starting from the region which has been made nonadhesive, until the core layer releases from at least one of the outer carrier layers so that the two substrates are separated from one another and on at least one of the two substrates an outer carrier layer is additionally bonded, and the outer carrier layer together with the first adhesive layer is peeled from the other substrate at an angle of removal of greater than 45°

.

19. The adhesive strip of claim 8 wherein the second adhesive layer has the same composition as the further adhesive layer.

17. (canceled)