COMPOSITE SYSTEM WITH GENTLY ADHERING LINER MATERIAL

Abstract

A double-sided adhesive tape having a heat-activatable adhesive layer protected with an interliner, in order to allow such tapes to be guided stably over cutting and winding units and also to be stably stored and transported, has a composite system comprising: an adhesive tape (A) comprising: a pressure sensitive adhesive layer, and a heat-activatable adhesive layer; a release liner situated on the pressure sensitive adhesive layer of the tape (A); and an adhesive tape (B) comprising: a carrier layer, a release layer on one side of the carrier layer, and a pressure sensitive adhesive layer on the side of the carrier layer opposite the release layer and in direct contact with the heat-activatable adhesive layer of tape (A).

Also disclosed is a method for producing a composite system of this kind, and the specific use of the tape (B).

Claims

1. Composite system comprising: an adhesive tape (A) comprising: a pressure sensitive adhesive layer, and a heat-activatable adhesive layer; a release liner situated on the pressure sensitive adhesive layer of the tape (A); and an adhesive tape (B) comprising: a carrier layer, a release layer on one side of the carrier layer, and a pressure sensitive adhesive layer on the side of the carrier layer opposite from the release layer; where the pressure sensitive adhesive layer of the tape (B) is in direct contact with the heat-activatable adhesive layer of the tape (A), and the tape (B) has a peel adhesion of not more than 5 N/cm, determined to EN 1939:2003, to the heat-activatable adhesive layer of the tape (A).

2. Composite system according to claim 1, wherein the pressure sensitive adhesive layer of the tape (A) comprises poly(meth)acrylate as principal constituent.

3. Composite system according to claim 1, wherein the tape (A) comprises a foamed pressure sensitive adhesive layer.

4. Composite system according to claim 3, wherein the foamed pressure sensitive adhesive layer of the tape (A) comprises at least partially expanded hollow microspheres.

5. Composite system according to claim 3, wherein the foamed pressure sensitive adhesive layer is the pressure sensitive adhesive layer of the tape (A).

6. Composite system according to claim 3, wherein the foamed pressure sensitive adhesive layer of the tape (A) is a carrier layer, with the heat-activatable adhesive layer arranged on one side thereof and the pressure sensitive adhesive layer arranged on the other side thereof.

7. Composite system according to claim 1, wherein the heat-activatable adhesive layer of the tape (A) is a polyolefin layer.

8. Composite system according to claim 1, wherein the tape (B) is broader than the tape (A) and broader than the release liner situated on the pressure sensitive adhesive layer thereof, and overhangs the tape (A) and the release liner on both sides.

9. Composite system according to claim 1, wherein the carrier layer of the tape (B) is a polyolefin film.

10. Composite system according to claim 1, wherein the pressure sensitive adhesive layer of the tape (B) comprises natural rubber or poly(meth)acrylate as principal constituent.

11. Method for producing a composite system according to claim 1, comprising the following steps: a) cutting a composite wound to a roll and composed of: an adhesive tape (A) comprising: a pressure sensitive adhesive layer, and a heat-activatable adhesive layer; and a release liner situated on the pressure sensitive adhesive layer of the tape (A) such that a plurality of rolls are obtained from a parent roll, the rolls having a web width lower than that of the parent roll; b) unrolling the rolls and covering a plurality of the resultant webs with an adhesive tape (B) comprising: a carrier layer, a release layer on one side of the carrier layer, and a pressure sensitive adhesive layer on the side of the carrier layer opposite from the release layer; such that the pressure sensitive adhesive layer of the tape (B) is in direct contact with the heat-activatable adhesive layer of the tape (A); c) cutting the tape (B) so as to form separate composite systems composed of tape (B), tape (A) and release liner, which can be wound back into rolls; where the tape (B) has a peel adhesion of not more than 5 N/cm, determined to EN 1939:2003, to the heat-activatable adhesive layer of the tape (A).

12. Method of covering a material in web form which is non-adhesively furnished on both sides, during the winding of this material to a roll and/or during the storage of that roll, said method comprising covering said material in web form with an adhesive tape (B) comprising: a carrier layer, a release layer on one side of the carrier layer, and a pressure sensitive adhesive layer on the side of the carrier layer opposite from the release layer, where the pressure sensitive adhesive layer of the tape (B) is in direct contact with one of the non-adhesively furnished sides of the material in web form.

Description

EXAMPLE

[0115] For producing the adhesive tape (A) in the sense of the present invention, a blown polypropylene film 40 μm thick was subjected on one side to CO.sub.2 corona treatment and was laminated by the side thus treated to a commercially available, double-sided acrylate foam adhesive tape (tesa® ACXplus 6808). A corresponding parent roll was unrolled, and a plurality of webs 8 mm wide were cut from the web and placed alongside one another. As adhesive tape (B) in the sense of the present invention (interliner), a commercially available adhesive strapping tape (tesa® Strapping 51128), based on a soft MOPP film provided on its reverse with a carbamate release layer, and on a natural rubber adhesive, was applied to the blown polypropylene film of each web (adhesive side of the strapping tape against the blown polypropylene film) in such a way that the strapping tape initially covered all of the webs comprehensively. The resulting assembly was passed through a further cutting unit. After it had passed through the cutting unit, individual webs of the 8 mm wide composite of tesa® ACXplus 6808 and the blown polypropylene film were present, lined with a 19 mm-wide web of the strapping tape in such a way that the strapping tape overhung by 5.5 mm on each side.

[0116] The peel adhesion between strapping tape and the composite made from tesa® ACXplus 6808 and the blown polypropylene film was found according to EN 1939:2003 to be 0.9 N/cm.

COMPARATIVE EXAMPLE

[0117] For producing the adhesive tape (A) in the sense of the present invention, a blown polypropylene film 40 μm thick was subjected on one side to CO.sub.2 corona treatment and was laminated by the side thus treated to a commercially available, double-sided acrylate foam adhesive tape (tesa® ACXplus 6808). A corresponding parent roll was unrolled, and a plurality of webs 8 mm wide were cut from the web and placed alongside one another. As interliner, an LDPE film 55 μm thick, coated on one side with a UV-crosslinked, solventlessly applied silicone release layer, was applied to the blown polypropylene film of each web in such a way that the interliner initially covered all of the webs comprehensively. The resulting assembly was passed through a further cutting unit. After it had passed through the cutting unit, individual webs of the 8 mm wide composite of tesa® ACXplus 6808 and the blown polypropylene film were present, lined with a 19 mm-wide web of the interliner in such a way that the interliner overhung by 5.5 mm on each side.

[0118] From the composite formed from an adhesive tape and interliner of the inventive example, the individual webs could be cut in dimensionally stable form, without problems, and passed through the system. In the comparative example, irregularities occurred, meaning that the specified width of the overhanging interliner should be regarded more as a target variable and less as the value actually achieved consistently.

[0119] The respective webs obtained from the inventive example and the comparative example were lattice-wound to give reels having a web length of 1400 m, which had a reel core overhang of 2 cm at each end. The reels were packed into cartons, 5 such cartons were stacked together, and 6 such stacks were joined to one another using a film. These assemblies were transported on the loading area of a vehicle over an identical distance of 10 km. The condition of the reels was then evaluated. It was found that the reels of the invention were completely intact and exhibited still, in particular, the overhang of the reel core at both ends, and also a stable winding.

[0120] The wound webs of the comparative example, in contrast, had slipped downwards, meaning that the reel core overhang was now still present only at the upper end. The wound plies had become partly inserted in one another, thus causing the plies to stick to one another (block); the reel could no longer be satisfactorily unwound and used.