ADHESIVE TAPE WITH A VISCOELASTIC POLYOLEFIN BACKING
The invention relates to an adhesive tape with a viscoelastic backing consisting of an olefin polymer with a density of between 0.86 and 0.89 g/cc and a crystallite melting point of at least 105° C., and also consisting of an adhesive resin.
1 . An adhesive tape comprising a viscoelastic carrier comprising an olefin polymer having a density of between 0.86 and 0.89 g/cm 3 and a crystallite melting point of at least 105° C. and comprising a tackifier resin.
2 . The adhesive tape as claimed in claim 1 ,wherein
the density of the olefin polymer is between 0.86 and 0.88g/cm 3 , and/or the olefin polymer has a crystallite melting point of at least 105° C.
3 . The adhesive tape as claimed in claim 1 , wherein
the olefin polymer has a melt index of less than 8 g/10 min, and/or
has a flexural modulus of less than 50 MPa.
4 . The adhesive tape as claimed in claim 1 , wherein
the olefin polymer comprises propylene or ethylene and at least one further comonomer selected from the C 2 to C 10 olefins.
5 . The adhesive tape as claimed in claim 1 , wherein the carrier comprises
a primary antioxidant, and/or
a secondary antioxidant in an amount of 0 to 5 phr, and/or
a light stabilizer, and/or
a UV absorber.
6 . The adhesive tape as claimed in claim 1 , wherein
the carrier comprises a tackifier resin which has a polydispersity of less than 2.1.
7 . The adhesive tape as claimed in claim 1 , wherein
the tackifier resin is selected from the group
of resins based on rosin or rosin derivatives,
of hydrocarbon resins based on C 5 monomers,
of hydrocarbon resins from hydrogenation of aromatics-containing hydrocarbon resins,
of hydrocarbon resins based on hydrogenated cyclopentadiene polymers, and/or
of resins based on polyterpenes,
of terpene-phenolic resins,
the amount of tackifier resin in the adhesive being 130 to 350 phr.
8 . The adhesive tape as claimed claim 1 , wherein
the carrier comprises a plasticizer selected from the group of mineral oils, of liquid polymers of isobutene homopolymer and/or isobutene-butene copolymer, and of esters of phthalic, trimellitic, citric or adipic acid.
9 . The adhesive tape as claimed in claim 1 , wherein
the carrier comprises a copolymer or a terpolymer of ethylene, propylene, but-1-ene, hex-1-ene and/or oct-1-ene, the flexural modulus of the copolymer or terpolymer being below 20 MPa and/or the crystallite melting point being below 50° C., and/or the density being between 0.86 and 0.87 g/cm 3 , or comprises an EPDM, having an ethylene content of 40% to 70% by weight and/or a density below 0.88 g/cm 3 , the amount of copolymer or terpolymer being above 100 phr.
10 . The adhesive tape as claimed in claim 1 , wherein
the carrier has a thickness of between 100 and 5000 μm.
11 . The adhesive tape as claimed in claim 1 , wherein
the carrier is not provided with any pressure-sensitive adhesive, or
the carrier is provided externally on one side or on both sides with a pressure-sensitive adhesive comprising acrylate.
12 . The adhesive tape as claimed in claim 1 , wherein
the 90° bond strength to polyethylene is at least 5 N/cm.
13 . The adhesive tape as claimed in claim 1 , wherein
the probe tack of the adhesive tape is at least 2 N.
14 . Method of bonding parts of an assembly comprising bonding said parts with an adhesive tape as claimed in claim 1 .