| CPC C09J 7/387 (2018.01) [C09J 7/26 (2018.01); C09J 11/08 (2013.01); C09J 153/02 (2013.01); C09J 2301/302 (2020.08); C09J 2301/312 (2020.08); C09J 2301/408 (2020.08); C09J 2301/50 (2020.08)] | 14 Claims |
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1. Pressure sensitive adhesive comprising
a) a base formulation containing
(i) 25 to 45 wt % of at least one elastomer component containing at least one polyvinylaromatic-polydiene block copolymer,
where the polyvinylaromatic-polydiene block copolymer at least fractionally has an A-B-A, (A-B)n, (A-B)nX or (A-B-A)nX structure, in which
the blocks A independently of one another are a polymer formed by polymerisation of at least one vinylaromatic,
the blocks B independently of one another are a polymer formed by polymerisation of conjugated dienes having 4 to 18 carbon atoms or are a derivative of such a polymer that is partially hydrogenated in the polydiene block,
X is the residue of a coupling reagent or initiator and
n is an integer≥2,
where the peak molar mass of the at least one polyvinylaromatic polydiene block copolymer according to Test IVa is at least 160 000 g/mol,
where the fraction of A blocks in the at least one polyvinylaromatic polydiene block copolymer is at least 8 wt % and at most 25 wt % and where optionally there may be a fraction of diblock copolymer A-B, containing blocks A and B as defined above, of at most 25 wt %, based on the total elastomer component,
(ii) 33 to 55 wt % of at least one tackifier resin component with at least one tackifier resin, where the at least one tackifier resin has a softening temperature (Ring & Ball, Test VII) of ≥80° C., and
(iii) 13 to 30 wt % of at least one reactive resin component containing at least 70 wt % of at least one reactive resin based on a cyclic ether having a dispersive component of the Hansen parameter, δD, of 17.50 to 17.82 MPa1/2,
based in each case on the base formulation, where the sum of the elastomer component and the reactive resin component is at least 38 wt % and at most 68 wt %,
b) 0.1 to 5 wt %, based on the amount of reactive resin component, of at least one initiator for the cationic curing of the at least one reactive resin,
c) optionally at least one plasticizer, and
d) optionally at least one additive.
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