D1365 BJ RADIATION CURABLE PRIMARY COATING FOR OPTICAL FIBER

Radiation curable coatings for use as a Primary Coating for optical fibers, optical fibers coated with said coatings and methods for the preparation of coated optical fibers. The present invention provides a radiation curable Primary Coating composition comprising: an oligomer; first diluent monomer; a second diluent monomer; a third diluent monomer; a first light stabilizer; a first photoinitiator; a second photoinitiator; an antioxidant; a second light stabilizer; and an adhesion promoter; wherein said oligomer is the reaction product of hydroxyl-containing acrylate; an isocyanate; a polyether polyol; a polymerization inhibitor; a catalyst; and a diluent; wherein said oligomer has a number average molecular weight of from at least about 4000 g/mol to less than or equal to about 15,000 g/mol; and wherein said catalyst is selected from the group consisting of copper naphthenate; cobalt naphthenate; zinc naphthenate; triethylamine; triethylenediamine; 2-methyltriethyleneamine; dibutyl tin dilaurate; metal carboxylates, including, but not limited to: organobismuth catalysts such as bismuth neodecanoate; zinc neodecanoate; zirconium neodecanoate; zinc 2-ethylhexanoate; sulfonic acids, including but not limited to dodecylbenzene sulfonic acid, methane sulfonic acid; amino or organo-base catalysts, including, but not limited to, 1,2-dimethylimidazole and diazabicyclooctane; triphenyl phosphine; alkoxides of zirconium and titanium, including, but not limited to Zirconium butoxide and Titanium butoxide; and Ionic liquid phosphonium salts; and tetradecyl(trihexyl) phosphonium chloride; and wherein a cured film of said radiation curable Primary Coating composition has a peak tan □ Tg of from about -25° C. to about -55° C.; and a modulus of from about 0.85 MPa to about 1.10 MPa.