Coatings for optical fibers

Improved heat-resistant UV compositions for optical fiber applications These compositions are nonurethane UV cure compositions that have neither carbamate moieties nor long-chain poly(alkylene oxide) soft segments and exhibit inherently better thermal stability measured by thermogravimetric analysis (TGA) than typical coatings for optical fibers based on urethane acrylate oligomers. 

Figure 4 Schematic of single and dual coatings for optical fibers.

Hot-melt thermoplastic primary coatings for optical fibers have also been employed to a limited extent (26,27). They may be formulated with reasonably low glass transition temperatures, but particle contamination is a difficult quality control problem with these materials. UV-curable coating formulations have largely supplanted hot melt coatings owing to the increased draw speed which they offer. 

Potential applications of GTP include high-performance automotive finishes, the fabrication of silicon chips, and coatings for optical fibers. 

The second patent [94] does not give further information about the synthesis but describes an application of these products — UV curing of coatings for optical fibers. Telechelics diols are used as coreagents for cationic polymerization of epoxy resins. Such coatings are composed of ... 

BLYLER AND ALOISIO Polymer Coatings for Optical Fibers... 

Figure 11. Master curves of the dynamic tensile moduli at -40 C for three representative types of primary buffer coatings for optical fibers.

The analysis of the diffusion-eontrolled features might be simplified by identifying the two types of free radieals the active and the trapped ones. Electron spin resonance speetroseopy shows that active (mobile) radicals give a 13-line spectrum and trapped (statie) radicals give a nine-line spectrum. Also, photopolymerization of a number of neat acrylate monomers used in polymer coatings for optical fiber was studied with photo DSC and with a cure monitor using a fluorescent probe. The acrylates had a functionality of one to six. It was found that conversion of monomers ranges from 40% to 100%. This, however, is depended upon functionality and structure of particular monomers. It can also be a function of the type and amount of the photoinitiator used. 

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