If at least one terpene-phenol resin is used as tackifying resin for pressure-sensitive adhesives based on polar framework polymers, wherein the at least one terpene-phenol resin in gel permeation chromatography analysis shows a multimodal molar mass distribution wherein the low molecular weight peak has its maximum within a range above 260 g/mol, it is possible, even at elevated temperatures, to achieve elevated storage stability of the terpene-phenol resins, apparent from a distinct reduction in increases in softening points over time.