Adhesive-coated thermally sensitive polymer substrate, process for its manufacture and use thereof

An adhesive-coated polymer substrate comprising:

• (a) a polymer substrate containing carbon black pigments and a thermoplastic polymer with a Vicat A50 softening point according to DIN EN ISO 306 of up to 220° C. and an additive selected from the group consisting of di-n-butyl-adipate, di-octyl-adipate, di-isononyl-phthalate, benzyl (2-ethyl-hexyl) adipate, mixtures of alkylsulphonic phenyl esters, mixtures of glycerine acetates, and adipic acid polyesters, and
• (b) a cured adhesive composition directly coated on at least one side of the polymer substrate, wherein the cured adhesive composition (b) is a UV-cured hot melt pressure sensitive adhesive (PSA) consisting of an acrylic copolymer having a viscosity of 20,000 to 35,000 mPas as measured in at 140° C. or a synthetic rubber copolymer and optionally, a tackifier or a plasticizer;
• wherein the acrylic copolymer is prepared from a mixture consisting of:
• (i) 0.1 to 30 weight-% of a methyl(meth)acrylate;
• (ii) 70 to 99.9 weight-% of n-butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, acrylic acid or mixtures thereof;
• and
• (iii) 0.05 to 10 weight-% of a photoinitiator;
• and,
• wherein the adhesive-coated polymer substrate is obtained by cross-linking the coated UV-curable hot melt pressure sensitive adhesive by a UV-C radiation source representing a medium pressure mercury lamp that emits light with a peak maximum at about 254 nm.