dl g the psa 39 s are hot melt coatable when the inherent viscosity of the radiation curable poly u03b1 olefin polymer is in the range of 1 5 to 4 0 dl g however radiation curable poly u03b1 olefin polymer having inherent viscosities in the range of 4 0 to 9 0 dl g may be coated from toluene solution by methods well known to those skilled in the art to yield cured psa films having superior shrink back scorch values and crack values number average molecular weights of the polymers are generally in the range of 5 000 to 50 000 000 the preferred psa radiation curable u03b1 olefin polymers used in the present invention have the general formula str1 r 1 can be selected from monovalent hydrocarbon groups containing 4 to 8 carbon atoms representative examples include but are not limited to 1 butyl 1 pentyl 1 hexyl 1 heptyl 1 octyl and branched hydrocarbon radicals such as 2 methylbutyl 2 ethyl butyl 3 methyl hexyl 2 ethyl hexyl 5 methyl hexyl 5 ethyl hexyl etc r 2 can be a monovalent hydrocarbon group containing one or more ethylenically unsaturated groups selected from the group consisting of ch 2 n r 3 ar r 3 ch 2 n q r 3 r 3 can be a c 2.