Radiation-curable coatings suitable for high-speed application onto optical fibers
AssigneeDsm N.V.
InventorsDavid Szum, Robert Johnson
Life of this patent
Estimating the term…
Abstract
Inner and outer primary and matrix material compositions which, after curing, exhibit a high degree of uniformity after curing even when the coating is applied onto optical fibers at relatively high shear rates, e.g., such as those experienced at high optical fiber coating line speeds. These compositions are provided in significant part by the selective incorporation of at least one radiation-curable oligomer into the compositions. In particular, and with respect to inner primary coatings, the oligomer should be selected so that the value m of an uncured radiation-curable inner primary coating composition in the equation τ = K λ γ 1 + ( λ γ ) m ( I ) is advantageously equal to or greater than about 0.90.
Claims22
A radiation-curable inner primary coating composition for optical fibers comprising at least one radiation-curable oligomer, wherein the value m of the uncured radiation-curable composition in the equation
- τ
- =
- K
-
-
- λ
-
-
- γ
- 1
- +
- (
- λ
-
-
- γ
- )
- m
- is equal to or greater than about 0.90, wherein τ is the shear stress (Pa) and γ is the apparent shear rate (sect−1).
10-21. (canceled)
A coated optical fiber prepared by a method comprising the steps of applying a radiation-curable inner primary coating composition onto an optical fiber while the fiber is moving at a speed of at least about 40 n/sec and curing the radiation-curable inner primary coating composition to provide the coated optical fiber, wherein the thickness of the cured inner primary coating on the coated optical fiber is substantially uniform.
A radiation-curable outer primary coating composition for optical fibers comprising at least one radiation-curable oligomer, wherein the value m of the uncured radiation-curable composition in the equation
- τ
- =
- K
-
-
- λ
-
-
- γ
- 1
- +
- (
- λ
-
-
- γ
- )
- m
- is equal to or greater than about 0.98, wherein τ is the shear stress (Pa) and γ is the apparent shear rate (sec−1).
29-49. (canceled)
Dependencies are inferred from the claim text.