Radiation curable thermoplastic polyurethanes

摘要: Radiation curable linear thermoplastic polyurethanes having imido pendent groups of the formula (A) ##STR1## wherein Z is an unsaturated C 2-12 hydrocarbyl or substituted group (preferably H 3 CC═CCH ) capable undergoing photocrosslinking with another like Z, are prepared by reaction (a) a macroglycol molecular weight 500-7,000, (b) one more glycol chain extenders each less than 500, which may include low aliphatic glycols (e.g., alkylene mixture thereof), and (c) organic diisocyanate. Either extender must radiation sensitive above (A). The herein have hard soft segments. Pendent present in segments when containing used, segment used. useful for various purposes including coatings magnetic recording media. curing gives thermoset polyurethane high hardness good solvent resistance.