Optical fiber ribbon

1. An optical fiber ribbon comprising:

first and second optical fibers arranged in parallel; and

at least one coupling member made of a resin material coupling the first and second optical fibers by adhering the first and second optical fibers each other intermittently in a longitudinal direction of the first and second optical fibers,

wherein a breaking elongation of the resin material constituting the coupling member is equal to or more than 200% and equal to or less than 500%,

wherein a tear strength of the coupling member is equal to or more than 0.25 N,

wherein the tear strength of the coupling member is equal to or less than 1.00 N, and

the tear strength is measured in accordance with IEC60794-1-2.

2. The optical fiber ribbon according to claim 1 , wherein a Young's modulus of the resin material constituting the coupling member is equal to or less than 50 MPa.

3. The optical fiber ribbon according to claim 2 , wherein the Young's modulus of the resin material is equal to or more than 1 MPa.

4. The optical fiber ribbon according to claim 1 , wherein a surface of the coupling member is recessed from an outermost layer of the optical fiber ribbon.

5. The optical fiber ribbon according to claim 1 , wherein the coupling member includes a plurality of glue drops.

6. The optical fiber ribbon according to claim 5 , wherein a diameter of each of the plurality of glue drops is between 0.2 mm and 0.3 mm.

7. The optical fiber ribbon according to claim 1 , wherein a connection region where the first and second optical fibers are connected each other by the coupling member and a non-connection region where the first and second optical fibers are not connected each other are alternately located in the longitudinal direction of the first and second optical fiber.

8. The optical fiber ribbon according to claim 7 , wherein a length of the connection region is less than that of the non-connection region.

9. The optical fiber ribbon according to claim 1 , wherein the coupling member is arranged only on one side of a plane including centers of the first and second optical fibers.

10. The optical fiber ribbon according to claim 1 , wherein

each of the first and second optical fibers comprises a single-core optical waveguide and a resin coating layer,

the resin coating layer includes

a primary resin layer contacting with an outer periphery of the optical waveguide, and

a secondary resin layer which contacts with an outer periphery of the primary resin layer, has a Young's modulus higher than the primary resin layer, and is colored, and

the coupling member contacts with the secondary resin layer.

11. The optical fiber ribbon according to claim 1 , wherein

each of the first and second optical fibers comprises:

first and second optical waveguides;

a first primary resin layer contacting with an outer periphery of the first optical waveguide;

a first secondary resin layer which contacts with an outer periphery of the first primary resin layer, has a Young's modulus higher than the first primary resin layer, and is colored;

a second primary resin layer contacting with an outer periphery of the second optical waveguide;

a second secondary resin layer which contacts with an outer periphery of the second primary resin layer, has a Young's modulus higher than the second primary resin layer, and is colored; and

a collective covering layer contacting with an outer periphery of the first and second secondary resin layers and collectively covering the first and second optical waveguides, and

the coupling member contacts with the collective covering layer.