Detachable adhesive strip
The invention relates to an adhesive film strip comprising at least two, particularly three, layers, which adhesive film strip can be detached without residues and nondestructively by expansive stretching substantially in the adhesion plane, with a carrier on which a first external adhesive compound layer is present on at least one side, wherein • the adhesive compound layer consists of adhesive compound formed on the basis of vinyl aromatic block copolymers and adhesive resins, wherein at least 75% of the resin (relative to the overall resin content) is selected with a DACP (diacetone alcohol cloud point) of greater than −20° C., preferably greater than 0° C., and • the carrier has at least one layer consisting of a polyurethane with an elongation at break of at least 100% and a restoring power of more than 50%. A nonpolar hydrocarbon resin or a polyterpene resin is particularly used as the tackifier for the adhesive compound(s).
1. A pressure-sensitive adhesive film strip consisting of:
a carrier comprising a first side, and a second side, and comprising at least one layer comprising a polyurethane;
a first, outer adhesive composition layer disposed on the first side; and
a second, outer adhesive composition layer disposed on the second side, wherein:
the first, outer adhesive composition layer comprises a first adhesive composition based on at least one first vinyl aromatic block copolymers and at least one first adhesive resin;
at least 75 wt. % of the at least one first adhesive resin has a diacetone alcohol cloud point of greater than −20° C.;
the at least one layer comprising a polyurethane has an elongation at break of at least 100% and a resilience of over 50%;
the first, outer adhesive composition layer, the carrier, and the second, outer adhesive composition layer are arranged congruently with the first, outer adhesive composition layer disposed above the carrier and the carrier disposed above the second, outer adhesive composition layer; and
the first, outer adhesive composition layer and the second, outer adhesive composition layer have identical compositions;
wherein if the pressure-sensitive adhesive film strip is adhered to a substrate so that an adhesion plane is formed, the pressure-sensitive adhesive film strip is detachable from the substrate by expansive stretching substantially in the adhesion plane without leaving a residue on the substrate and without causing damage to the substrate.
2. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the at least one layer consists of a single layer.
3. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the at least one first vinyl aromatic block copolymers comprises:
one or more polymer blocks formed predominantly of vinyl aromatic compounds (A blocks); and
one or more polymer blocks formed predominantly by polymerization of 1,3-dienes (B blocks).
4. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the at least one first vinyl aromatic block copolymers has a content of polyvinyl aromatic compounds of from 10 wt. % to 35 wt. %.
5. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the at least one first vinyl aromatic block copolymer comprises one or more polystyrene end blocks.
6. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the amount of the at least one first vinyl aromatic block copolymer is from 20 to 70 wt. % based on the first, outer adhesive composition layer.
7. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein at least 75 wt. % of the at least one first adhesive resins comprises at least one hydrocarbon resin, at least one terpene resin or a mixture thereof.
8. The pressure-sensitive adhesive film strip as claimed in claim 1 , wherein the carrier is from 10 to 200 μm thick.
9. The pressure-sensitive adhesive film strip of claim 1 , wherein the at least one first adhesive resin is incompatible with the carrier.
10. The pressure-sensitive adhesive film strip of claim 1 , wherein the at least one first adhesive resin does not migrate from the first, outer adhesive composition layer.
11. The pressure-sensitive adhesive film strip of claim 1 , wherein the pressure-sensitive adhesive film strip is from 50 to 150 μm thick.
12. The pressure-sensitive adhesive film strip of claim 1 , wherein:
the pressure-sensitive adhesive film strip forms a cuboid comprising a top, a bottom, and four sides;
the cuboid further comprises three layers stacked one on top of the other; and
each of the three layers extends to each of the four sides so that each of the four sides has a surface that is flat and even.
13. A method comprising bonding an object to a substrate via the pressure-sensitive adhesive film strip as claimed in claim 1 .
14. A combination consisting of:
a first substrate;
a second substrate; and
a pressure-sensitive adhesive film strip as claimed in claim 1 ,
wherein:
the first, outer adhesive composition layer is bonded to the first substrate forming a first adhesive bond in a first adhesion plane;
the second, outer adhesive composition layer is bonded to the second substrate forming a second adhesive bond in a second adhesion plane;
the first adhesion plane and the second adhesion plane extending parallel to one another; and
the first adhesive bond and the second adhesive bond being releasable by expansive stretching by pulling on the pressure-sensitive adhesive film strip substantially in both the first adhesion plane and the second adhesion plane.