Optical waveguides – Optical fiber waveguide with cladding
Patent
1994-05-26
1995-10-24
Berman, Susan W.
Optical waveguides
Optical fiber waveguide with cladding
427503, 427515, 428391, 428447, 522 18, 522 96, 522172, G02B 600, B05D 306, C08F 250, C08F 254
Patent
active
054616913
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a liquid, beam-curable coating composition for coating glass surfaces, comprising ethylenically unsaturated polyurethane which optionally contains urea groups, ethylenically unsaturated monomer, photoinitiator and
The present invention furthermore relates to a process for coating glass surfaces, in particular optical glass fibers, using these beam-curable coating compositions.
Optical glass fibers have acquired a constantly increasing importance as light wave conductor fibers in the field of communications. For this intended use, it is absolutely essential to protect the glass surface from moisture and wear phenomena. The glass fibers are therefore provided with a protective coat of varnish directly after their production.
It is thus known, for example from EP-B-114,982, first to provide glass fibers with a buffer coat (primer) which is elastic but not very hard and not very tough, and then to apply a beam-curable top coating which has a high hardness and toughness. The two-coat build-up should guarantee good protection of the glass fibers under mechanical stress, even at low temperatures. Beam-curable coating compositions based on a polyurethane containing diethylenic end groups, a diethylenically saturated ester of a diglycidyl ether of a bisphenol, and a monoethylenically unsaturated monomer, the glass transition temperature of the homopolymer prepared from this monomer being above 55.degree. C., are employed as the top coating in EP-B-114,982.
However, such glass fiber coatings have the considerable disadvantage of only poor adhesion to the glass surface. This adhesion is worsened still further under exposure to moisture in particular, and under certain circumstances even to the extent that complete loss of adhesion to the glass surface occurs. The problem of poor adhesion of coating compositions to the surface of glass is known. Organosilanes are therefore often added to the coating compositions as adhesion promoters in order to improve the adhesion.
Liquid, beam-curable glass fiber coating agents which, in addition to a beam-curable polyethylenically unsaturated polymeric compound, comprise 0.5 to 5%, based on the coating composition, of a polyalkoxysilane are known from EP-A-149,741. Those polyalkoxysilanes which carry an organic substituent which carries a single active amino- or mercapto-hydrogen atom which can react with the ethylenically unsaturated bonds in a Michael addition are suitable. .gamma.-Mercaptopropyltrimethoxysilane is mentioned as an example of suitable silanes. According to the doctrine of EP-A-149,741, it is possible to improve adhesion even under exposure to moisture only by using such silanes.
Liquid, beam-curable glass fiber coating agents which comprise a diethylenically unsaturated polyurethane resin as the binder and ethylenically unsaturated monomers as reactive diluents furthermore are known from DE-OS 38 40 644. To improve the adhesion even under exposure to moisture, these glass fiber coating agents comprise 0.05 to 6% by weight of N-.beta.-aminoethyl-.gamma.-aminopropyltrimethoxysilane, .gamma.-amino-propyltrimethoxysilane, N-methyl-.gamma.-aminopropyl-trimethoxysilane or triamino-modified propyltri-methoxysilane. However, these glass fiber coating agents are still in need of improvement in respect of production reliability.
Solutions based on polycondensates having N-containing heterocyclic ring systems which comprise azidosilanes as adhesion promoters furthermore are known from the not yet published German Patent Application P 4107664.8. However, the addition of azidosilanes to beam-curable coating compositions based on ethylenically unsaturated polyurethanes is not described.
Finally, it is known from the not yet published German Patent Application P 4113655.1 [lacuna] a mixture of azidosilanes and aminoalkoxysilanes as an adhesion promoter between inorganic substrates and polycondensates which contain, as structural units, heterocyclic ring systems having N atoms. The addition of these adhesion promoters to beam-curable coating comp
REFERENCES:
patent: 3715371 (1973-02-01), Thomson
patent: 4002651 (1977-01-01), Marsden et al.
patent: 4038456 (1977-07-01), Marsden et al.
patent: 4401598 (1983-08-01), Karl et al.
patent: 4447495 (1984-05-01), Engle, III
patent: 4812519 (1989-03-01), Gillette
patent: 5252403 (1993-10-01), Blum et al.
patent: 5286527 (1994-02-01), Blum et al.
patent: 5302458 (1994-04-01), Blum et al.
Blum Rainer
Hintze-Bruning Horst
Schunck Stephan
BASF Lacke & Farben AG
Berman Susan W.
Sabourin Anne Gerry
LandOfFree
Liquid, radiation-curable coating composition for coating glass does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid, radiation-curable coating composition for coating glass , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid, radiation-curable coating composition for coating glass will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1892701