Optical fiber

Patent metadata

Field	Value
Publication number	US-9874684-B2
Application number	US-201615521360-A
Country	US
Kind code	B2
Filing date	Nov 7, 2016
Priority date	Nov 9, 2015
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

An optical fiber comprises a glass fiber, and a coating resin layer having a primary resin layer and a secondary resin layer, wherein the primary resin layer consists of a cured resin composition containing an oligomer, a monomer and a photopolymerization initiator, the oligomer is a reaction product of a specific polyol compound, a polyisocyanate compound, and a hydroxyl group-containing acrylate compound, the photopolymerization initiator includes 2,4,6-trimethylbenzoyldiphenyl phosphine and 1-hydroxycyclohexyl phenyl ketone at a mass ratio of 5:1 to 1:1, and a content of 2,4,6-trimethylbenzoyldiphenyl phosphine in the resin composition is 1.5 to 2.5% by mass.

First claim

The invention claimed is:

1. An optical fiber comprising:
a glass fiber having a core and a cladding with which the core is covered, and a coating resin layer with which the glass fiber is covered, wherein
the coating resin layer has a primary resin layer and a secondary resin layer,
the primary resin layer consists of a cured resin composition for covering optical fibers containing an oligomer, a monomer and a photopolymerization initiator,
the oligomer is a reaction product of a polyol compound having an average molecular weight of 3000 to 6000, a polyisocyanate compound including 2,4-tolylene diisocyanate or 2,6-tolylene diisocyanate, and a hydroxyl group-containing acrylate compound,
the photopolymerization initiator includes 2,4,6-trimethylbenzoyldiphenyl phosphine and 1-hydroxycyclohexyl phenyl ketone at a mass ratio of 5:1 to 1:1,
a content of the 2,4,6-trimethylbenzoyldiphenyl phosphine in the resin composition is 1.5 to 2.5% by mass, and
a change in yellow index value between before and after irradiation with fluorescent light at a distance of 30 cm from a 30-W fluorescent lamp at room temperature for 30 days is 30 or less.

2. The optical fiber according to claim 1 , wherein
the monomer includes an N-vinyl compound.

3. The optical fiber according to claim 1 , wherein
a Young's modulus of the primary resin layer is 0.7 MPa or less at 23° C.

4. The optical fiber according to claim 1 , wherein
an outer diameter is 210 μm or less,
a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and
a Young's modulus of the secondary resin layer is 800 MPa or more at 23° C.

5. The optical fiber according to claim 4 , wherein
a Young's modulus of the secondary resin layer is 900 MPa or more at 23° C.

6. The optical fiber according to claim 4 , wherein
a Young's modulus of the secondary resin layer is 1000 MPa or more at 23° C.

7. The optical fiber according to claim 1 , wherein
the secondary resin layer includes a cured resin composition containing 2,4,6-trimethylbenzoyldiphenyl phosphine and 1-hydroxycyclohexyl phenyl ketone as photopolymerization initiators at a mass ratio of 1:10 to 1:20.

8. The optical fiber according to claim 2 , wherein
a Young's modulus of the primary resin layer is 0.7 MPa or less at 23° C.

9. The optical fiber according to claim 2 , wherein
an outer diameter is 210 μm or less,
a Young's modulus of the primary resin layer is 0.5 MPa or less at 23° C., and
a Young's modulus of the secondary resin layer is 800 MPa or more at 23° C.

10. The optical fiber according to claim 9 , wherein
a Young's modulus of the secondary resin layer is 900 MPa or more at 23° C.

11. The optical fiber according to claim 9 , wherein
a Young's modulus of the secondary resin layer is 1000 MPa or more at 23° C.

Assignees

• Sumitomo Electric Industries

Inventors

• Iwaguchi Noriaki
• Iida Masuo
• Fujii Takashi

Classifications

• C08G18/7621

  being toluene diisocyanate including isomer mixtures · CPC title

• G02B6/03694

  Multiple layers differing in properties other than the refractive index, e.g. attenuation, diffusion, stress properties · CPC title

• C03C25/1065

  Multiple coatings · CPC title

• C08F290/062

  Polyethers · CPC title

• C08G18/672

  Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen · CPC title