STRONG CARBOXYLIC ACID FUNCTIONAL POLYURETHANE POLYMERS AND BLENDS THEREOF USED IN MAGNETIC RECORDING MEDIA

摘要

The invention provides novel hydroxyl functional polyurethanes which can be used in magnetic media binders applications. The polyurethanes comprise strong carboxylic acid groups pendant from the polymer backbone, which groups can be produced by esterification of backbone hydroxyl moieties with cyclic dicarboxylic acid anhydrides. Examples of anhydrides useful in preparation of the polyurethanes include anhydrides of tetrachlorophthalic acid, tetrafluorophthalic acid, and dichloromaleic acid, etc. The polyurethanes, which are optionally radiation curable, show high affinity for magnetic pigments, and blends of the polyurethanes with vinyl and non-vinyl resins afford excellent binders for magnetic recording media.