Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
1997-04-11
2001-02-20
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...
C522S097000, C522S042000, C522S120000, C522S121000, C428S378000, C428S380000, C428S383000
Reexamination Certificate
active
06191187
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical glass fiber coating composition suitable for use as a primary coating on an optical glass fiber. More particularly this invention relates to an optical glass fiber coating composition having a low viscosity, exhibiting superior storage stability over an extended period of time, and providing a cured material having various excellent characteristics.
2. Description of Related Art
An optical fiber is provided with a resin coating with the object of protecting and reinforcing the bare optical fibers threads. The coating is applied immediately after hot melt spinning of the glass fiber. A structure consisting of a flexible primary coating layer on the surface of the optical fiber and a secondary coating layer outside of this primary coating layer is known as such a resin coating.
The coating material used to form these coatings must have the following characteristics:
(1) be a liquid at room temperature and have high processability;
(2) provide good productivity at a high curing rate;
(3) exhibit very little physical change during temperature changes over a wide range;
(4) have superior heat resistance and superior resistance to hydrolysis;
(5) show superior long term storage stability with little physical changes over time;
(6) show superior resistance to chemicals such as acids and alkalis;
(7) exhibit low moisture and water absorption;
(8) exhibit superior ultraviolet light (UV) resistance;
(9) have excellent oil resistance;
(10) generate a minimal amount of hydrogen gas which affects optical fibers
(11) have superb yellowing resistance against light and heat; and
(12) exhibit only slight shrinkage during curing.
A number of radiation-curable liquid resin compositions have been developed in an attempt to satisfy these requirements.
FR-A-2629218, for instance, describes an optical glass fiber coating composition suitable for use as a primary coating on an optical glass fiber, comprising a urethane acrylate oligomer and 15 to 40 weight % of isobornylacrylate as reactive acrylate diluent. The coating of FR-A-2629218 has a good adhesion to glass, gives suitable protection of the glass fiber and has a high curing speed.
In order to promote the productivity of optical fibers, it is essential that the drawing speed from melted glass fiber materials be elevated. At a high drawing speed, however, the conventional optical glass fiber coating compositions have a problem of generating a large quantity of volatile matters due to polymerization heat or radiation heat from radiation sources such as an ultraviolet lamp or the like.
U.S. Pat. No. 4,992,524 discloses an acrylate urethane oligomer, in combination with a reactive diluent and a photoinitiator. In the list of reactive diluents, at column 6, lines 1-42 2-hydroxy-3-phenoloxypropyl(meth)acrylate is mentioned. However, the disclosure of (U.S. Pat. No. 4,992,524) is absent of any specific preference for this compound, nor is there any teaching which would lead the skilled man to use this compound, in combination with other reactive diluents, in order to make coating compositions that exhibit low weight reduction (of the liquid coating composition).
SUMMARY OF THE INVENTION
Accordingly, an objective of the present invention is to provide an optical glass fiber coating composition which has a low viscosity at room temperature, exhibits superior storage stability over a long period of time, produces a minimal amount of hydrogen, exhibits suitable adherence to optical fibers, generates a low amount of volatile matters when coated to optical fibers and cured, and in the cured state exhibits excellent UV-resistance, heat resistance, yellowing resistance, and oil resistance.
These objectives and other objectives is achieved in the present invention by the provision of an optical glass fiber coating composition comprising:
(A) a urethane (meth)acrylate polymer,
(B) a (meth)acrylate compound represented by the following formula (1):
wherein R
1
is a hydrogen or a methyl group,
(C) a reaction diluent, and
(D) a polymerization initiator.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
The urethane (meth)acrylate polymer (A) used in the present invention can be prepared, for example, by the condensation reaction of a polyol compound (a), a polyisocyanate compound (b), and a (meth)acrylate compound having a hydroxy group (c).
Examples of the polyol compound (a) are polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol, and polyester diols obtained by ring-opening copolymerization of two or more types of ionic-polymerizable cyclic compound.
Examples of ionic-polymerizable cylic compounds include cyclic ethers such as ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2- or 3-methyl-tetrahydrofuran, dioxane, trioxane, tetraoxane, cyclohexene oxide, styrene oxide, epichlorhydrin, glycidyl methacrylate, acryl glycidyl ether, allyl glycidyl carbonate, butadiene monoxide, isoprene monoxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether, and glycidylbenzoate. Specific examples of combinations of the two or more types of ionic-polymerizable cyclic compounds which can be given include tetrahydrofuran and propylene oxide; tetrahydrofuran and 2-methyltetrahydrofuran; tetrahydrofuran and ethylene oxide; propylene oxide and ethylene oxide; and butene oxide and ethylene oxide. Either random or block bonded ring-opening copolymers of these ionic-polymerizable cyclic compounds may be used.
These polyether polyols may be available as commercial products, such as PTMG 1000 and PTMG 2000 (Mitsubishi Chemical Industries, Ltd.); PPG 1000, EXCENOL 2020, EXCENOL 1020 (Asahi Oline); PEG 1000, UNISAFE DC 1100, UNISAFE DC 1800 (Nippon Oil and Fats Co., Ltd.); PPTG 2000, PPTG 1000, PTG 400, PTG 650, PTGL 2000, PTGL 4000, (Hodogaya Chemical Co., Ltd.); and Z-4441-1, PBG 2000A, PBG 2000B, Z-3001-4, Z-3001-5, Z-3001-9, Z-3001-15, (Dai-ichi Kogyo Seiyaku).
It is also possible to use a polyether diol obtained by the ring-opening copolymerization of the above mentioned ionic polymerizable cyclic compounds and a cyclic imine such as ethylene imine or the like; a cyclic lactone such as p-propiolactone, glycolic acid lactide, or the like; or dimethylcyclopolysiloxane, as the polyol compound (a).
Beside these polyether polyols, polyester polyols, polycarbonate polyols, and polycaprolactone polyols can be used. These polyols may be used in combination with polyether polyols (a). There are no specific limitations to the method of condensation of these structural units. They may be polymerized by random, block, or graft polymerization.
Examples of the polyester polyols which can be used include polyester polyols obtained by the reaction of a polyhydric alcohol, such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerine, tetramethylene glycol, polytetramethylene glycol, 1,6-hexane diol, neopentyl glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentane diol, 1,9-nonane diol, or 2-methyl-1,8-octane diol, and a polybasic acid, such as phthalic acid, isophtalic acid, terephtalic acid, maleic acid, isophtalic acid, terephthalic aid, maleic acid, fumaric acid, adipic acid, or sebacic acid. Commercially available products which can be given include Kurapole P-2010, PMIPA, PKA-A, PKA-A2, and PNA-2000, all manufactured by Kuraray Co., Ltd.
As polycarbonate polyols, 1,6-hexane polycarbonate diol, and commercially available products, such as DN-980, DN-981, DN-982, DN-983 (Nihon Polyurethane), PC-8000 (PPG of the US), and PTHFCD 1000, PTHFCD 2000 (BASF) can be given as examples.
Further, examples of polycaprolactone polyols are those obtained by the reaction of &egr;-caprolactone and a diol, such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerine, tetramethylene glycol, polytetramethylene glycol, 1,2
Komiya Zen
Ukachi Takashi
Ukon Masakatsu
Yamamura Tetsuya
DSM N.V.
McClendon Sanza L.
Pillsbury Madison & Sutro
Seidleck James J.
LandOfFree
Optical glass fiber coating compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical glass fiber coating compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical glass fiber coating compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2577078