| 摘要 |
Improved radiation curable polyurethanes are provided that are polymerizable crystalline polymers having terminal ethylenic unsaturation, relatively low molecular weights and that rapidly crystallize, are prepared from the reaction product of (1) certain polyester glycols and diisocyanates to form an isocyanate-terminated prepolymer that is then reacted with an ethylenic unsaturated alcohol to form the ethylenic unsaturated crystallizable polymer, or in the alternative, (2) the polyester glycol is reacted with an ethylenic unsaturated monoisocyanate to form the polymerizable crystallizable polymer, that can be used as such for example in preparing magnetic tape, as such, or in admixture with other materials, and which can be applied to a substrate from a melt, or formed by molding, extrusion, and then cured with appropriate energy as an electron beam.
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