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.
High-refractive-index transparent coatings enhance the optical fiber cladding modes refractometric sensitivity
