Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
1998-08-21
2001-10-23
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C522S096000, C522S118000, C522S120000, C522S127000, C522S115000, C522S171000, C428S380000, C428S378000, C428S383000, C385S128000, C385S145000
Reexamination Certificate
active
06306924
ABSTRACT:
TECHNICAL FIELD
This invention relates to improved curable coating compositions for glass substrates and to glass substrates, such as optical fibers, coated with the compositions.
BACKGROUND OF THE INVENTION
It has long been known that glass substrates are weakened upon exposure to water. For example, moisture in air can cause weakening and the eventual breakage of glass.
Typically, glass substrates have been coated with polymeric compositions for various reasons, such as to protect and preserve the strength of a glass object, to prevent damage during handling, and to prevent moisture from attacking the glass substrate. In addition, coatings have been applied to optical fibers to decrease the microbending of the optical fiber, which can reduce the transmission of electromagnetic radiation through the fiber. However, it has been found that many coating compositions are water permeable, and therefore not very effective in protecting the glass substrate from moisture.
In addition to causing the weakening of glass substrates, moisture can also cause polymeric compositions that have been applied to the glass substrate to break away, i.e., delaminate, from the glass surface. The delamination of a polymeric composition can result in a weakened glass substrate, as the polymeric coating no longer protects the glass from environmental stresses.
Various coating compositions have been used to prevent the deterioration of glass substrates, and specifically optical fibers, to improve the useful life of the glass substrate to which it is applied. For example, U.S. Pat. No. 5,000,541, issued to DiMarcello et al., teaches a method for hermetically sealing an optical fiber with carbon, which prevents water from contacting the optical fiber, and thus prolongs the useful life of the optical fiber. Similarly, U.S. Pat. No. 4,849,462, issued to Bishop et al., teaches the incorporation of various organofunctional silanes into a coating composition to improve the adhesion between a coating composition for an optical fiber and the optical fiber, particularly in moist environments.
Likewise, U.S. Pat. No. 5,214,734, issued to Inniss et al., teaches the incorporation of particulate silica in a polymeric coating composition to increase the fatigue resistance of an optical fiber or glass to moisture.
Similarly, U.S. Pat. No. 5,136,679, issued to Broer et al., shows an inner primary coating that comprises an acidic phosphorus compound as an adhesion promotor. However, because it is hypothesized in the Broer et al. patent that an acid medium develops near the interface of the glass fiber and the first (inner primary) coating composition due to the presence of the phosphorus compound, this patent teaches away from the use of acidic phosphorus compounds in an outer primary coating or any other coating layer that does not directly contact the optical glass fiber.
Many coating compositions have drawbacks that make them unsuitable for certain applications. For example, some of the compositions may be too expensive to use in the production of low cost optical fibers or glass objects, and the introduction of particulate matter into a coating composition as disclosed in the Inniss et al. patent can present problems such as scratching of the pristine optical glass fiber, resulting in breakage at low tensile loads; a turbid coating composition which has a tendency to gel; and other processing problems that are commonly encountered when working with particulate matter.
Coatings which are modified with organofunctional silanes, such as the above-referenced Bishop et al. patent, do improve the wet adhesion of a coating applied to an optical fiber substrate, but do not significantly improve the wet adhesion retention capability of the coating, when compared to this invention.
SUMMARY OF THE INVENTION
This invention provides an improved coating composition for glass substrates, preferably silica-based optical fibers, wherein the composition contains a tetrasubstituted compound having the formula:
wherein A is Si, Ti or Zr, and where X
1
, X
2
, X
3
and X
4
are hydrolyzable groups that can be hydrolyzed from the tetrasubstituted compound in the presence of water.
Preferably, the hydrolyzable groups X
1
, X
2
, X
3
and X
4
are independently an alkoxy group or a group containing ethylenic unsaturation.
Preferably, the tetrasubstituted compound is present in the coating composition in an amount in the range of about 0.1% to about 50% by weight of the entire composition. More preferably, this amount is about 0.1 to about 30%, and most preferably about 0.5 to about 10%.
This invention further relates to a coating composition having an adhesion retention, as defined below, of at least 80%, preferably at least 85%, and most preferably at least 95%.
In addition, this invention provides coating compositions for glass substrates that comprise a strong acid functional ethylenically unsaturated monomer.
This invention also provides improved glass substrates that are coated with at least one polymeric coating composition that comprises a tetrasubstituted compound and/or a strong acid functional ethylenically unsaturated monomer. The resulting coated glass substrates have decreased rates of deterioration due to moisture attack, improved adhesion between the glass substrate and the coating adjacent to the glass, and improved adhesion between coating layers if more than one coating layer containing a tetrasubstituted compound is applied to the glass substrate.
REFERENCES:
patent: 3816152 (1974-06-01), Yates
patent: 4272586 (1981-06-01), Ando et al.
patent: 4640938 (1987-02-01), Romer et al.
patent: 4735856 (1988-04-01), Schultz et al.
patent: 4849462 (1989-07-01), Bishop
patent: 5039716 (1991-08-01), Vara et al.
patent: 5091211 (1992-02-01), Richard
patent: 5095086 (1992-03-01), Pawar et al.
patent: 5112658 (1992-05-01), Skutnik et al.
patent: 5128387 (1992-07-01), Shustack
patent: 5128391 (1992-07-01), Shustack
patent: 5136679 (1992-08-01), Broer et al.
patent: 5146531 (1992-09-01), Shustack
patent: 5157755 (1992-10-01), Ooe et al.
patent: 5181269 (1993-01-01), Petisce
patent: 5212757 (1993-05-01), Brownlow et al.
patent: 5214734 (1993-05-01), Inniss et al.
patent: 5229433 (1993-07-01), Schunck et al.
patent: 5232783 (1993-08-01), Pawar et al.
patent: 5385955 (1995-01-01), Tarshani et al.
patent: 5502145 (1996-03-01), Szum
patent: 5595820 (1997-01-01), Szum
patent: 6014488 (2000-01-01), Shustack
patent: 2252344 (1986-04-01), None
patent: 01067284 (1987-09-01), None
patent: 8502106 (1985-07-01), None
patent: 90/13523 (1990-11-01), None
International Search Report of International Application No. PCT/NL 94/00308.
DSM Desotech Inc.
McClendon Sanza L.
Pillsbury & Winthrop LLP
Seidleck James J.
LandOfFree
Radiation-curable glass coating composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radiation-curable glass coating composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radiation-curable glass coating composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2616605