Ultraviolet Curable Silicone Optical Fiber Coatings

Abstract

ABSTRACTTechnology coupling fast ultraviolet (UV) cure response with elastomeric properties in silicone formulations has been developed. Rapid photocure was obtained through addition of mercaptan to vinyl on silicon via a free radical chain reaction resulting in a monosulfide link. One optical fiber coating based on the technology, OPTIGARD™ X3-6662, is a onepart formulation which can be cured very rapidly (≤0.1 sec) upon UV exposure (≥25 mJ/cm2) to provide a low refractive index (RI=1.42), elastomeric film exhibiting good low temperature properties. A high refractive index counterpart (RI=1.51), OPTIGARD™ X3-6663, was obtained through incorporation of a controlled amount of phenyl groups into the polymer backbone. The technology, an IR-100 Award winner in 1985, is being used by the fiber optic industry to satisfy their need for coatings which will cure fast, perform over a wide temperature range, and be moisture insensitive.