Pressure-sensitive adhesive
A pressure-sensitive adhesive is to achieve good bond strengths at both high and low temperatures. This aim is accomplished by the adhesive comprising the following components: a) 40-70 wt %, based on the total weight of the adhesive, of at least one poly(meth)acrylate; b) 15-50 wt %, based on the total weight of the adhesive, of at least one synthetic rubber; and c) at least one tackifier compatible with the poly(meth)acrylate(s). The invention further relates to an adhesive tape which comprises at least one layer of the pressure-sensitive adhesive of the invention.
1 . A pressure-sensitive adhesive comprising:
a) 40-70 wt %, based on the total weight of the adhesive, of at least one poly(meth)acrylate;
b) 15-50 wt %, based on the total weight of the adhesive, of at least one synthetic rubber; and
c) at least one tackifier compatible with the poly(meth)acrylate(s).
2 . The pressure-sensitive adhesive according to claim 1 , wherein the weight ratio of poly(meth)acrylates to synthetic rubbers is from 1:1 to 3:1.
3 . The pressure-sensitive adhesive according to claim 1 wherein the weight ratio of tackifiers compatible with the poly(meth)acrylates to synthetic rubbers is at most 2:1.
4 . The pressure-sensitive adhesive according to claim 1 wherein the weight ratio of tackifiers compatible with the poly(meth)acrylates to the synthetic rubbers is at least 1:4.
5 . The pressure-sensitive adhesive according to claim 1 wherein the synthetic rubber is a block copolymer having an A-B, A-B-A, (A-B) n , (A-B) n X or (A-B-A) n X construction,
in which
the blocks A independently of one another are a polymer formed by polymerization of at least one vinylaromatic;
the blocks B independently of one another are a polymer formed by polymerization of conjugated dienes having 4 to 18 C atoms and/or isobutylene, or are a partially or fully hydrogenated derivative of such a polymer;
X is the residue of a coupling reagent or initiator and
n is an integer ≧2.
6 . The pressure-sensitive adhesive according to claim 5 , wherein the weight fraction of the blocks A, based on all block copolymers present in the adhesive, is 10 to 40 wt %.
7 . The pressure-sensitive adhesive according to claim 1 wherein the tackifier compatible with the poly(meth)acrylates is a terpene-phenolic resin or a rosin derivative.
8 . The pressure-sensitive adhesive according to claim 1 wherein the adhesive is foamed.
9 . An adhesive tape comprising at least one layer of a pressure-sensitive adhesive according to claim 1 .
10 . The adhesive tape according to claim 9 , wherein the thickness of the layer is 100 μm to 5000 μm.
11 . The adhesive tape according to claim 9 wherein the adhesive tape comprises a layer of a pressure-sensitive adhesive according to claim 1 .