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

Abstract

The invention relates to an adhesive-coated polymer substrate comprising (a) a polymer substrate containing or consisting of a thermoplastic polymer with a Vicat A50 softening point according to DIN EN ISO 306 of up to 220° C., and (b) an adhesive composition coated directly on at least one side of the polymer substrate, wherein the adhesive composition (b) is a UV-curable or UV-cured hot melt pressure sensitive adhesive (PSA). The invention relates moreover to a process for the manufacture of the adhesive-coated polymer substrate as well as to the use thereof.

1 : A process for the manufacturing an adhesive-coated polymer substrate comprising the steps:
 (i) providing 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 optionally, an additive;   (ii) coating directly a UV-curable hot melt pressure sensitive adhesive on at least one side of the substrate; and   (iii) curing the UV- curable hot melt pressure sensitive adhesive by irradiation with UV light.   
     
     
         2 : The process according to  claim 1 , wherein the UV-curable hot melt pressure sensitive adhesive is irradiated and cross-linked with a UV light source such that the temperature at a distance of from 15 to 50 mm next to the surface of the coating of the UV-curable hot melt pressure sensitive adhesive on the substrate does not exceed an upper temperature T max  of 120° C. 
     
     
         3 : The process according to  claim 2 , wherein the polymer substrate is made from soft PVC and the UV-curable hot melt pressure sensitive adhesive is an acrylic copolymer containing 0.1 to 30 weight-% methyl(meth) acrylate monomer. 
     
     
         4 : The process according to  claim 3 , wherein the UV-curable hot melt pressure sensitive adhesive further comprises a mixture of alkyl(meth)acrylates which is 70 to 99.9 weight-%, based on the mixture, of C 2  to C 18  alkyl(meth)acrylates. 
     
     
         5 : The process according to  claim 4 , wherein the mixture of alkyl(meth)acrylates is n-butyl acrylate, ethyl acrylate and/or 2-ethylhexyl acrylate.