| abstract |
An ultraviolet curing liquid coating composition is provided which, when cured with ultraviolet light in the presence of an appropriate photoinitiator, provides a buffer coating for optical glass fiber having adequate strength at room or expected elevated temperature and stability at such elevated temperature, a high index of refraction above 1.48, and a low tensile modulus which remains low to resist microbending difficulties down to around -60° C. This coating composition consists essentially of a linear acrylate-terminated polyurethane oligomer including urea groups introduced by the presence in the oligomer of the reaction product with isocyanate functionality of about 30% to about 90% by weight of the acrylate-terminated oligomer of a polyoxyalkylene diamine having a molecular weight in the range of from about 1000 to about 8000 in which the alkylene group contains from 2-4 carbon atoms. |