Ultraviolet curable coatings for optical glass fiber based on a polyfunctional core

摘要

An ultraviolet curing liquid coating composition which, when cured with ultraviolet light in the presence of an appropriate photoinitiator, provides a coating adapted for the coating of optical glass fiber. This coating composition comprises as the essential component, an acrylate-terminated polyurethane oligomer based on a polyfunctional core which is at least trifunctional and which supports one branch for each functionality in the core. Each of the branches leads to an acrylate-functional terminal group, with there being from about 150 to about 2500 units of molecular weight in each branch between the trifunctional core and the acrylate-functional terminal group. Depending primarily upon the molecular weight of the branches, one can provide coating compositions for buffer coat, single coat or topcoat use.