Patent ID: 7317858

Claim:
An optical fiber comprising an internal glass portion, a first coating layer surrounding said glass portion and a second coating layer surrounding said first coating layer, wherein said first coating layer is formed from a cured polymeric material obtained by curing a radiation curable composition comprising a radiation curable oligomer comprising a backbone derived from polypropylene glycol and a dimer acid based polyester polyol, said cured polymeric material having: a) a hardening temperature (Th) from −10° C. to about −20° C. and a modulus measured at said Th lower than 5.0 MPa; or b) a hardening temperature (Th) from −20° C. to about −30° C. and a modulus measured at said Th lower than 20.0 MPa; or c) a hardening temperature (Th) lower than about −30° C. and a modulus measured at said Th lower than 70.0 MPa.