ADHESIVE TAPE HAVING A CARRIER WHICH IS COMPOSED OF ONE OR MORE CARRIER FILMS, THE CARRIER BEARING ON AT LEAST ONE SIDE AN ADHESIVE APPLIED AT LEAST PARTIALLY
Adhesive tape having a carrier which is composed of one or more carrier films, at least one side of the carrier bearing an adhesive applied at least partially, characterized in that at least one of the carrier films comprises at least one homopolymer, copolymer or terpolymer of propylene and in that there are carbon nanotubes (CNTs) in at least one of the carrier films.
1 . Adhesive tape having a carrier which is composed of one or more carrier films, at least one side of the carrier bearing an adhesive applied at least partially, characterized in that at least one of the carrier films comprises at least one homopolymer, copolymer or terpolymer of propylene and in that there are carbon nanotubes (CNTs) in at least one of the carrier films.
2 . Adhesive tape according to claim 1 , wherein the carrier has been oriented in the machine direction or is composed of a single carrier film, or is both composed of a single carrier film and oriented in the machine direction.
3 . Adhesive tape according to claim 1 , wherein
the carrier has a machine-direction tensile strength of at least 300 N/mm 2 , or
the carrier has a machine-direction stress at 10% extension of at least 170 N/mm 2 or
the carrier has a thickness of between 25 and 200 μm, or any combination of said properties.
4 . Adhesive tape according to claim 1 , wherein the carrier film or films have been oriented in machine direction with a draw ratio of 1:5 to 1:10.
5 . The adhesive tape according to claim 1 , wherein the carrier comprises a polypropylene raw material having a melt index of 0.3 to 15 g/10 min or having a flexural modulus of between 1000 and 1450 MPa or having both said melt index and said flexural modulus.
6 . Adhesive tape according to claim 1 , wherein the CNTs are multiwalled carbon nanotubes (MWNT).
7 . The adhesive tape according to claim 1 , wherein the CNTs have an aspect ratio of less than 10 000.
8 . Adhesive tape according to claim 1 , wherein the CNTs are in dispersion in the film or films at a concentration of 0.1% to 30% by weight.
9 . Adhesive tape according to claim 1 , wherein the CNTs are chemically functionalized or modified.
10 . Adhesive tape according to claim 1 , wherein the adhesive is applied at a coating thickness in the range of from 18 to 50 g/m 2 .
11 . Process for producing an adhesive tape of claim 1 , comprising the steps of:
mixing of the polypropylene with CNTs, optionally with subsequent granulation
optionally, melting of a compound of polypropylene and CNTs in an extruder
cooling of the melt to form a film in an extrusion or calendering process
drawing of the film in machine direction
coating with adhesive
converting to form rolls.
12 . Process for producing an adhesive tape according to claim 11 , wherein compatibilizers are added to ensure better dispersing and processing of the CNTs.
13 . The adhesive tape of claim 3 , wherein said tensile strength is at least 500 N/mm 2 , said stress is at least 300 N/mm 2 and said thickness is between 50 and 90 μm.
14 . The adhesive tape of claim 5 , wherein said melt index is 2 to 10 g/10 min.
15 . The adhesive tape of claim 7 , wherein said aspect ratio is less than 1000.
16 . The adhesive tape of claim 8 , wherein said concentration is 0.5 to 5% by weight.
17 . The adhesive tape of claim 10 , wherein said coating thickness is 22 to 29 g/m 2 .