Primary optical fiber coating composition containing non-radiation curable component
An optical fiber is disclosed that includes a primary coating formed from a radiation curable composition that includes a curable cross-linker essentially free of urethane and urea functional groups, a curable diluent, and a non-radiation curable component comprising (thio)urethane and/or (thio)urea groups. The primary coating features low Young's modulus, low T g , and high tensile strength. The optical fiber exhibits low microbend losses in wire mesh drum and basketweave tests.
1. A coated optical fiber comprising:
a glass fiber; and
a primary coating surrounding said glass fiber, said primary coating including the cured product of a radiation-curable composition comprising:
a first radiation-curable component; and
a non-radiation-curable component, said non-radiation-curable
component including (thio)urethane and/or (thio)urea groups;
wherein said primary coating has an in situ Young's modulus of less than 1 MPa.
2. The coated optical fiber of claim 1 , wherein said first radiation-curable component is essentially free of urethane and urea groups.
3. The coated optical fiber of claim 1 , wherein said first radiation-curable component is a radiation-curable cross-linker.
4. The coated optical fiber of claim 1 , wherein said first radiation-curable component is a radiation-curable diluent.
5. The coated optical fiber of claim 4 , wherein said radiation-curable composition further includes a second radiation-curable component, said second radiation-curable component including a radiation-curable cross-linker.
6. The coated optical fiber of claim 5 , wherein said radiation-curable composition includes 25-50 wt % of said radiation-curable diluent, 4-40 wt % of said radiation-curable cross-linker, and 15-35 wt % of said non-radiation-curable component.
7. The coated optical fiber of claim 5 , wherein said cured product includes a network, said network including chemical bonds between said radiation-curable cross-linker and said radiation-curable diluent, said network excluding chemical bonds between said non-radiation-curable component and said radiation-curable cross-linker, said network further excluding chemical bonds between said non-radiation-curable component and said radiation-curable diluent.
8. The coated optical fiber of claim 1 , wherein the non-radiation curable component is branched.
9. The coated optical fiber of claim 1 , wherein the non-radiation curable component comprises a core moiety covalently linked to two or more block moieties, each of said block moieties comprising some of said (thio)urethane and/or (thio)urea groups.
10. The coated optical fiber of claim 9 , wherein said block moieties terminate in a non-radiation-curable capping agent.
11. The coated optical fiber of claim 1 , wherein said non-radiation curable component comprises a structure according to formulae (Ia) or (Ib)
wherein,
R 1 is a multifunctional core moiety, where the number of functional groups of the core moiety is defined by p, where p is 2 or greater each X is independently S or O;
Z 1 is —O—, —S—, —N(H)—, or —N(alkyl)-;
each of Q 1 and Q 2 is independently —O—, —S—, —N(H)—, or —N(alkyl)-;
each of R 2 and R 4 is a core moiety of a di(thio)isocyanate reactant;
R 3 is a core moiety of a polyol or amine-capped polyol reactant;
R 5 is a hydrocarbon or oxygen-containing hydrocarbon having an average molecular weight of between about 28 to about 400;
R 6 is represented by the structure according to formula (II) or (III)
where X is defined as above, Z 2 is —O—, —S—, —N(H)—, or —N(alkyl)-, R 7 is a core moiety of a di(thio)isocyanate reactant, R 8 is a non-radiation curable capping agent, and R 9 is a core moiety of an isocyanate or thioisocyanate reactant;
l is 1 to 6;
m is greater than or equal to 0; and
n is greater than or equal to 1.
12. The coated optical fiber of claim 1 , wherein said non-radiation-curable component has a molecular weight between 4000 and 50000 daltons.
13. The coated optical fiber of claim 1 , wherein said cured product, when configured as a film of thickness ˜80 μm, has a tensile strength of at least 0.6 MPa.
14. The coated optical fiber of claim 1 , wherein said primary coating has an in situ Young's modulus less than 0.6 MPa.
15. The coated optical fiber of claim 1 , wherein said primary coating has an in situ T g less than −30° C.
16. The coated fiber of claim 1 , further comprising a secondary coating, said secondary coating surrounding said primary coating, said secondary coating, when configured as a film of thickness cured rod having a diameter of 0.022″, having a Young's modulus of at least 1400 MPa and an average tensile strength of at least 45 MPa.
17. The coated optical fiber of claim 16 , wherein said fiber has a wire mesh drum microbend loss of less than 0.020 db/km at a wavelength of 1310 nm, less than 0.015 db/km at a wavelength of 1550 nm, or less than 0.050 db/km at a wavelength of 1625 nm.
18. The coated optical fiber of claim 1 , wherein said fiber has a basketweave microbend loss, following thermal cycling over a temperature range from −40° C. to 70° C., of less than 0.010 db/km at a wavelength of 1310 nm, less than 0.010 db/km at a wavelength of 1550 nm, or less than 0.010 db/km at a wavelength of 1625 nm.
19. The coated optical fiber of claim 1 , wherein said fiber has a basketweave microbend loss, following thermal cycling from 23° C. to −60° C., of less than 0.015 db/km at a wavelength of 1310 nm, less than 0.030 db/km at a wavelength of 1550 nm, or less than 0.045 db/km at a wavelength of 1625 nm.
20. An optical fiber ribbon or bundle comprising:
a plurality of coated optical fibers according to claim 1 ; and
a matrix encapsulating said plurality of coated optical fibers.