Radiation-curable fiber optic materials having reduced moisture content

a technology of fiber optic materials and fiber optic fibers, applied in the direction of coatings, polyurea/polyurethane coatings, etc., can solve the problems of optical glass fiber delaminate from the inner primary coating layer, optical glass fiber weakened upon exposure to water, and optical glass fiber eventual breakage, etc., to achieve the effect of prolonging the shelf li

Inactive Publication Date: 2002-01-31
DSM NV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This approach extends the shelf-life of radiation-curable fiber optic materials and ensures consistent adhesion to optical glass fibers, reducing delamination and improving storage stability, thereby enhancing the reliability and performance of fiber optic coatings.

Problems solved by technology

Microbending is associated with attenuation of the signal transmission capability of the coated optical glass fiber and is therefore undesirable.
In general, optical glass fibers are weakened upon exposure to water.
For example, moisture in air can cause weakening and the eventual breakage of optical glass fibers.
In addition to causing the weakening of the optical glass fibers, moisture can also cause the inner primary coating layer to delaminate from the optical glass fiber.
The delamination of the inner primary coating from the optical glass fiber further results in a weakened optical glass fiber, because the inner primary coating can no longer protect the optical glass fiber from attack from moisture.
Delamination may also cause attenuation of the signal transmission capability of the coated optical glass fiber.
However, for certain applications, conventional radiation-curable, optical glass fiber coating compositions may not provide cured inner primary coatings having sufficient reliability and consistency in resistance to delamination caused by moisture.
Moreover, when suitable compositions have been formulated, erratic and inconsistent performance on the glass fiber has been observed.
It has also been found that the resistance to delamination of the cured inner primary coating from an optical fiber decreases with the age or shelf-life of the radiation-curable, optical glass fiber coating composition, and this decrease may be erratic from one batch of composition to another.
Such inconsistency can have severe repercussions in optical fiber technology.
Materials with insufficient shelf life may need to be discarded.

Method used

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  • Radiation-curable fiber optic materials having reduced moisture content
  • Radiation-curable fiber optic materials having reduced moisture content
  • Radiation-curable fiber optic materials having reduced moisture content

Examples

Experimental program
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Effect test

example 1

[0106] The amount of water necessary to hydrolyze the functionally-effective glass-binding groups of gamma-mercaptopropyltrimet-hoxysilane was determined. Gamma-mercaptopropyltrimethoxysilane contains in theory at least three alkoxy groups which are capable of binding to glass. However, it has been found that when one of the three alkoxy groups reacts with water via hydrolysis to form a hydroxyl group the other two alkoxy groups are significantly less active or are entirely unable to effect a bonding of the coating composition with the glass fiber surface under typical radiation-curing conditions and subsequent storage of coated glass.

[0107] It has also been found that the gamma-mercaptopropyldimethoxyhydrox-ysilane formed from the hydrolysis of gamma-mercaptopropyltrimethoxysilane will undergo an in situ condensation reaction according to the above formula 2 to produce water under normal shelf storage conditions.

example 2

[0108] The effect of the amount of water present in radiation-curable, inner primary, glass optical fiber compositions on the adhesion of the cured inner primary coating to glass was tested. Two radiation-curable compositions were made using the components shown in Table 1. The amount of water was varied, as shown in Table 2. Variance of water content was the result of determining the amount of water in each of the components prior to making the compositions. For example, Ethoxylatednonylphenolmono-acrylate, available as SR504A (Sartomer), determined to have a relatively low water content, was selected for use in sample 1 and Photomer 4003, determined to have a relatively high water content, was selected for use in sample 2.

[0109] The compositions of sample 1 and sample 2 after aging under normal storage conditions were tested to determine the amount of effective adhesion promoter remaining in the compositions.

[0110] Sample 1, the composition known to have the lower water content in...

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Abstract

A method of making radiation-curable, fiber optic materials having extended shelf-life and reduced water content which when suitably cured provide reliable and consistent adhesion characteristics to optical glass fibers.

Description

FIELD OF THE INVENTION.[0001] This invention provides a method for making radiation-curable fiber optic materials having an extended shelf-life, and in particular, materials which comprise hydrolyzable glass coupling agent and which have reduced moisture content.DESCRIPTION OF RELATED ART[0002] Optical glass fibers are frequently coated with two or more superposed radiation-curable coatings, which together form a primary coating. The coating which contacts the optical glass fiber is called the "inner primary" coating and the overlaying coating is called the "outer primary" coating. Alternatively, the inner primary coating may simply be called the "primary" coating and the outer primary coating the "secondary" coating. Other optical fiber materials include matrix materials, inks, and bundling materials. All of these fiber optic materials are preferably radiation-curable and are within the scope of the present invention. Coated optical fibers can be incorporated into ribbon and cable ...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C03C25/10C03C25/26C08F2/46C03C25/24C08G18/67C09D4/00C09D4/06C09D175/16
CPCC03C25/106C03C25/26C08G18/672C09D4/00C09D4/06C09D175/16C08G18/44C08G18/48C08F220/30C08F290/06C08F222/1065
InventorCHAWLA, CHANDER P.SCHMID, STEVEN R.ZIMMERMAN, JOHN M.JULIAN, JAMES M.
OwnerDSM NV