US 10,884,182 B2 · Thermally resistant radiation curable coatings for optical fiber

Abstract

Described herein are coated optical fibers including an optical fiber portion, wherein the optical fiber portion includes a glass core and cladding section that is configured to possesses certain mode-field diameters and effective areas, and a coating portion including a primary and secondary coating, wherein the primary coating is the cured product of a composition that possesses specified liquid glass transition temperatures, such as below −82° C., and/or a viscosity ratios, such as between 25° C. and 85° C., of less than 13.9. Also described are radiation curable coating compositions possessing reduced thermal sensitivity, methods of coating such radiation curable coating compositions to form coated optical fibers, and optical fiber cables comprising the coated optical fibers and/or radiation curable coating compositions elsewhere described.

Claims29

Dependent claims

A coated optical fiber, comprising:

an optical fiber portion, said optical fiber portion further comprising
a glass core, and
a cladding layer in contact with and surrounding said glass core;
and
a coating portion, said coating portion further comprising
a primary coating layer in contact with and surrounding said cladding layer;
and
a secondary coating layer in contact with and surrounding said primary coating layer;
wherein said primary coating layer is the cured product of a radiation curable composition comprising
a urethane acrylate oligomer which is the reaction product of an isocyanate, a polyol, and an acrylate monomer;
a reactive diluent monomer;
and
a free-radical photoinitiator;
wherein the radiation curable composition possesses a liquid glass transition temperature (Tg,rheo), of less than −82° C.;
and wherein the coated optical fiber possesses a mode-field diameter from 8 to 10 μm at a wavelength of 1310 nm, and/or an effective area between 20 and 200 μm2.

12 more elements

A method for producing a coated optical fiber comprising the steps of:

(a) drawing a glass optical fiber through a draw tower;
(b) applying a primary coating composition onto the surface of the glass optical fiber;
(c) optionally, imparting a dose of UV light sufficient to at least partially cure said primary coating composition;
(d) applying a secondary coating composition to the primary coating composition;
(e) exposing the primary coating composition and the secondary coating composition to at least one radiation source capable of emitting ultraviolet radiation to affect curing of said primary coating composition and said secondary coating composition, to form a cured primary coating on the surface of the optical fiber, and a cured secondary coating on the surface of the cured primary coating;
wherein the primary coating composition comprises a reactive oligomer comprising at least one polymerizable group and a backbone derived from a diol comprising
polypropylene glycol;
a reactive diluent monomer;
and
one or more photoinitiators;
wherein the radiation curable composition possesses a liquid glass transition temperature (Tg,rheo), a first viscosity at 25° Celsius (C), a second viscosity at 55° C., and a third viscosity at 85° C.;
wherein the Tg,rheo of the radiation curable composition is from −120 to −82° C., wherein Tg,rheo is determined by fitting equation (8) to experimental viscosity versus temperature data for the radiation curable composition:
η
⁡
(
T
)
/
η
25
=
10
⁢
(
-
562.5
/
(
62.5
-
T
g
,
rheo
)
*
(
T
-
25
)
37.5
+
T
-
T
g
,
rheo
)
,
(
8
)
where η(T) is the viscosity (in Pa·s) of the composition at temperature, T (in ° C.), and η25 is the first viscosity;
and
wherein the ratio of the first viscosity to the third viscosity is less than about 13.9.

54 more elements

Dependencies are inferred from the claim text.

Thermally resistant radiation curable coatings for optical fiber

Life of this patent

Thermally resistant radiation curable coatings for optical fiber

Life of this patent

Abstract

Claims29