Process for preparing a thermally reactive pressure-sensitive adhesive

Abstract

The in-line repair operations in the automotive industry require high-temperature masking tapes which satisfy a particular profile of requirements. Hence such masking tapes must be temperature-stable and must have a high crosslinking potential. Masking tapes employed are tapes coated with thermally crosslinking natural rubber (NR) adhesives which have a crosslinker resin/phenolic resin component. Thermally reactive pressure-sensitive adhesives of this kind are prepared by a process comprising a non-thermoplastic rubber constituent of the pressure-sensitive adhesive and a crosslinker system, the crosslinker system comprising a promoter component and as crosslinking component a reactive phenolic resin, where, in the process, the rubber constituent and a first component of the crosslinker system are mixed homogeneously in a mixing assembly, at a first processing temperature of the mixing assembly, to give a premix, a premix temperature being established in the premix; subsequently the premix is cooled from the premix temperature to a final composition temperature which is lower than the first premix temperature; and lastly the second component of the crosslinker system is added to the premix.

Dependencies are inferred from the claim text.