METHOD FOR INCREASING THE ADHESIVE POWER OF A PRESSURE-SENSITIVE ADHESIVE LAYER HAVING AN UPPER AND A LOWER SURFACE
Method for increasing the adhesive power of a pressure-sensitive adhesive layer having an upper and a lower surface, wherein at least one surface of the pressure-sensitive adhesive layer is subjected to a physical process, said physical process being selected from among the group comprising corona discharge, dielectric barrier discharge, preliminary flame treatment, or plasma treatment.
1 . A method for increasing the bond strength of a layer of pressure-sensitive adhesive (PSA) having a top and a bottom surface, said method comprising subjecting the PSA layer at least on one surface side to a physical method, the physical method being selected from the group consisting of corona discharge, dielectric barrier discharge, flame pretreatment, and plasma treatment.
2 . The method as claimed in claim 1 ,
wherein
the physical method is conducted in a treatment atmosphere formed by the following pure or mixtures of process gases: N 2 , O 2 , H 2 , CO 2 , Ar, He, ammonia, and ethylene, it also being possible for steam or other volatile constituents to have been added.
3 . The method as claimed in claim 2 ,
wherein
the physical method takes place at or near to atmospheric pressure.
4 . The method as claimed in claim 2 ,
wherein
reactive aerosols are present in or added to the treatment atmosphere.
5 . The method as claimed in claim 1 ,
wherein
both surfaces of the PSA layer are subjected to a physical method.
6 . The method as claimed in claim 1 ,
wherein
both surfaces of the PSA layer are subjected to a physical method in such a way as to produce unequal bond strengths on the two sides.
7 . The method as claimed in claim 1 ,
wherein
the physical method is a plasma treatment at or near to atmospheric pressure.
8 . The method as claimed in claim 1 ,
wherein
PSA layer is based on natural rubber, synthetic rubber, polyurethanes, or acrylate.
9 . The method as claimed in claim 1 ,
wherein
the substrate to which the PSA layer is to be bonded has been physically pretreated.
10 . A method for producing an adhesive tape, the method comprising applying adhesive to a carrier, and increasing the bond strength by subjecting one free surface to a physical method, the physical method being selected from the group consisting of corona discharge, dielectric barrier discharge, and plasma treatment.