A thermally curable hot-melt adhesive composition, comprising
a polyurethane prepolymer having isocyanate groups, wherein at least
50% of the reactive isocyanate groups of the prepolymer are blocked, said prepolymer
being the reaction product of
(1) 20 to 40 wt % of at least one straight-chain amorphous polyester
having a number average molecular mass Mn of 3000 to 6000 with
(2) 40 to 60 wt % of at least one polyurethane elastomer,
(3) 10 to 20 wt % of at least one polyester elastomer,
(4) at least one diisocyanate,
(5) at least one polyol as a chain extender, and
(6) at least one blocking agent; and
at least one isocyanate reactive component selected from the group consisting
of polyalcohols, polyamines and hydroxy-functionalized epoxide resins;
wherein the percentages are based on the total weight of polyester, polyurethane
elastomer and polyester elastomer.
