Halogenated dihydroxy-terminated polybutadienes for optical fiber coating

Abstract

Abstract A radiation-curable polyethylenically unsaturated polyurethane resin is disclosed which cures to provide cured coatings possessing reasonable physical integrity at room temperature, a tensile modulus of less than about 10000 psi at -40°C., preferably less than 5000 psi at -60°C., and a high index of refraction, above 1.48. This polyurethane resin is constituted by an essentially saturated, halogenated, dihydroxy-terminated linear liquid polybutadiene polymer, in which the halogen is preferably chlorine, reacted with an organic diisocyanate and an ethylenically unsaturated monomer carrying a single hydroxy group to form a diethylenic diurethane having a halogen-containing essentially saturated polybutadiene backbone. Coating compositions are disclosed which consist essentially of the above polyethylenically unsaturated diurethane having a polybutadiene backbone together with less than 40% of a liquid solvent therefor which is preferably a monoethylenically unsaturated liquid having a low glass transition temperature, and the compositions preferably include a photoinitiator enabling cure on ultraviolet exposure. These coatings are used as a buffer coating on optical glass fiber.

Inventors

• 👤 John J. Krajewski

Bibliographic Details