Optical fiber
An optical fiber includes an optical transmission medium having a core and a cladding, a primary resin layer disposed in contact with the optical transmission medium to coat the optical transmission medium, and a secondary resin layer coating the primary resin layer, wherein a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and the primary resin layer comprises a cured product of an ultraviolet light curable resin composition containing a urethane (meth)acrylate oligomer, a monomer, a photopolymerization initiator and a β-diketone compound, and tin.
1. An optical fiber comprising:
an optical transmission medium having a core and a cladding;
a primary resin layer disposed in contact with the optical transmission medium to coat the optical transmission medium; and
a secondary resin layer coating the primary resin layer,
wherein a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and
the primary resin layer comprises a cured product of an ultraviolet light curable resin composition containing a urethane (meth)acrylate oligomer, a monomer, a photopolymerization initiator and a β-diketone compound, and tin,
wherein the β-diketone compound is a compound selected from acetylacetone, acetoacetic acid, 2-acetoacetoxypropyl (meth)acrylate, 2-acetoacetoxybutyl (meth)acrylate, and 2,3-di(acetoacetoxy)propyl (meth)acrylate.
2. The optical fiber according to claim 1 , wherein 10 to 1000 ppm of the tin is contained in the primary resin layer.
3. The optical fiber according to claim 1 , wherein the Young's modulus of the primary resin layer is 0.25 MPa or less at 23° C.
4. The optical fiber according to claim 1 , wherein the β-diketone compound is contained in an amount of 0.01 to 10 parts by mass relative to a total amount of 100 parts by mass of the resin composition.
5. The optical fiber according to claim 1 , wherein the β-diketone compound is a compound having a polymerizable group.