A heat-activatable adhesive comprising from about 30 to about 70 wt. % of
one or more elastomers, from about 20 to about 60 wt. % of one or more
novolac phenolic resins, and an effective amount of one or more
crosslinking agents capable of effecting crosslinking of the one or more
novolac phenolic resins, wherein the ratio of the mass of the one or more
novolac phenolic resins over the mass of the one or more elastomers is at
least about 0.65.