EP0155070B1
Expired / Lapsed
EP
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Coated optical fiber, fabrication process thereof and fabrication apparatus thereof
Assignee: NTT Inc
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Filing: 1985-01-22
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Granted: 1989-03-29
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Expires: 2005-01-22
Abstract
No abstract record available.
Inventors
- 👤 Makoto Wagatsuma
- 👤 Fumio Yamamoto
- 👤 Takao Kimura
- 👤 Yoshito Shuto
- 👤 Shinzo Yamakawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:10
CPC Classifications
C; C03; C03C; C03C25/00; C03C25/10; C03C25/12; C03C25/18; C03C25/104; C03C25/1065; G; G02; G02B; G02B6/00; G02B6/02; G02B6/036; B; B29; B29C; B29C48/00; B29C48/03; B29C48/05; B29C48/07; B29C48/08; B29C48/09
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
144 words
A coated optical fiber comprising an optical fiber, a first layer which is a rubber composition and which is disposed around the circumference of said optical fiber, and a second layer which is a thermoplastic resin composition and which is disposed around the circumference of said first layer, characterized in that (a) said rubber composition of said first layer is a thermoplastic rubber composition which has a Young's modulus of 0.1 GPa or less and is capable of extrusion coating, (b) said thermoplastic resin composition of said second layer exhibits liquid crystallizability in molten state and its oriented state is maintained by forcible cooling immediately after the coating step and (c) said thermoplastic resin composition has a linear expansion coefficient of 7 x 10 -5° C -1 or less and a Young's modulus of 4.3 GPa or more and is capable of extrusion coating.
Claim 2
Dependent Claim
144 words
A coated optical fiber comprising an optical fiber, a first layer which is a rubber composition and which is disposed around the circumference of said optical fiber, and a second layer which is a thermoplastic resin composition and which is disposed around the circumference of said first layer, characterized in that (a) said rubber composition of said first layer is a thermoplastic rubber composition which has a Young's modulus of 0.1 GPa or less and is capable of extrusion coating, (b) said thermoplastic resin composition of said second layer exhibits liquid crystallizability in molten state and its oriented state is maintained by forcible cooling immediately after the coating step and (c) said thermoplastic resin composition has a linear expansion coefficient of 7 x 10 -5° C -1 or less and a Young's modulus of 4.3 GPa or more and is capable of extrusion coating.
Claim 3
Dependent Claim
28 words
A coated optical fiber as claimed in claim 1, characterized in that the thermoplastic rubber composition of said first layer contains a styrene copolymer or an olefine copolymer.
Claim 4
Dependent Claim
69 words
A coated optical fiber as claimed in claim 1, characterized in that the thermoplastic resin composition of said second layer is composed of polyethylene terephthalate-p-hydroxybenzoic acid copolymer containing 40-70 mol% of p-hydroxybenzoic acid or a blend prepared from said copolymer and other polymer, and that said resin composition presents molecular orientation in lengthwise direction of the fiber at a rate of shear of 10 2 sec -1 or more.
Claim 5
Dependent Claim
58 words
A coated optical fiber as claimed in claim 1 characterized in that the thermoplastic rubber composition of said first layer comprises: A: a styrene/butadiene block copolymer (20-40 wt% styrene concentration), B: a naphthenic processing oil, and C: a heat stabilizer, as the major components, and that concentrations of the respective components of said composition are so determined that
Claim 6
Dependent Claim
57 words
A coated optical fiber as claimed in claim 1, characterized in that said thermoplastic resin composition of said second layer is selected from the group consisting of all aromatic polyesters, aromatic-fatty polyesters, all aromatic polyester amides, aromatic-aliphatic polyester amides, aromatic polyazomethines, aromatic polyester-carbonates, the mixtures thereof, or mixtures of said high-molecular materials with the other high-molecular materials.
Claim 7
Dependent Claim
189 words
A process for fabricating a coated optical fiber in which an optical fiber preform is spun by heating so that said optical fiber preform is softened to form an optical fiber, characterized in that said optical fiber is extrusion-coated simultaneously with (a) a first layer of a thermoplastic rubber composition which has a Young's modulus of 0.1 GPa or less and which is capable of extrusion coating and (b) a second layer of a molecular-orientated thermoplastic resin composition which exhibits liquid crystallizability in molten state and which has a linear expansion coefficient of 7 x 10-' * C-' or less which has a Young's modulus of 4.3 GPa or more and which is capable of extrusion coating; said extrusion-coating being carried out immediately after the spinning step by an applicator and that at least said second layer, of said simultaneously coated first and second layers, is forcibly cooled to the crystallization temperature of the molecular-orientated thermoplastic resin composition or less before the coated optical fiber reaches a distance x from the outlet of the applicator, where x/V ≤1 and V(m/sec) is the speed of travel of the optical fiber.
Claim 8
Dependent Claim
189 words
A process for fabricating a coated optical fiber in which an optical fiber preform is spun by heating so that said optical fiber preform is softened to form an optical fiber, characterized in that said optical fiber is extrusion-coated simultaneously with (a) a first layer of a thermoplastic rubber composition which has a Young's modulus of 0.1 GPa or less and which is capable of extrusion coating and (b) a second layer of a molecular-orientated thermoplastic resin composition which exhibits liquid crystallizability in molten state and which has a linear expansion coefficient of 7 x 10-' * C-' or less which has a Young's modulus of 4.3 GPa or more and which is capable of extrusion coating; said extrusion-coating being carried out immediately after the spinning step by an applicator and that at least said second layer, of said simultaneously coated first and second layers, is forcibly cooled to the crystallization temperature of the molecular-orientated thermoplastic resin composition or less before the coated optical fiber reaches a distance x from the outlet of the applicator, where x/V ≤1 and V(m/sec) is the speed of travel of the optical fiber.
Claim 9
Dependent Claim
64 words
A process for fabricating a coated optical fiber as claimed in claim 6, characterized in that said coated optical fiber is cooled forcibly by the use of coolant, which is selected from the group consisting of liquids, gases, or the mixtures thereof having a specific heat of 0.1 kcal/kg°C or more at an ordinary temperature and a thermal conductivity of 0.01 kcai/m.hr.°C or more.
Claim 10
Dependent Claim
28 words
A process for fabricating a coated optical fiber as claimed in claim 6, characterized in that said molecular-orientated thermoplastic resin composition is a thermotropic liquid crystalline high-molecular material.
Claim 11
Dependent Claim
68 words
A process for fabricating a coated optical fiber as claimed in claim 6, characterized in that said molecular-orientated thermoplastic resin composition is selected from polyethylene terephthalate-p-hydroxybenzoic acid copolymers containing 40-70 mol% of p-hydroxybenzoic acid or blends prepared from said copolymers and other polymers, and that said resin composition exhibits molecular orientation, in lengthwise direction of the fiber at a rate of shear of 10 2 sec-1 or more.
Claim 12
Dependent Claim
27 words
A process for fabricating a coated optical fiber as claimed in claim.6, characterized in that said thermoplastic rubber composition contains a styrene copolymer or an ethylene-a-olefine copolymer.
Claim 13
Dependent Claim
69 words
A process for fabricating a coated optical fiber as claimed in claim 6, characterized in that said thermoplastic rubber composition comprises a styrene/butadiene block copolymer containing 20-40% by weight of styrene, a naphthenic processing oil, and a heat stabilizer as the major components, and that an amount of said naphthenic processing oil is 5-150 parts by weight with respect to 100 parts by weight of said styrene/butadiene block copolymer.
Claim 14
Independent Claim
264 words
An apparatus for fabricating a coated optical fiber wherein, immediately after spinning an optical fiber from an optical fiber preform by heating to soften said optical fiber preform, said optical fiber is coated with a first layer of a thermoplastic rubber compositon which has a Young's modulus of 0.1 GPa or less and is capable of extrusion coating and a second layer of a molecular-orientated thermoplastic resin composition which exhibits liquid crystallizability in molten state and which has a linear expansion coefficient of 7 x 10- 5 °C-' or less and a Young's modulus of 4.3 GPa or more and is capable of extrusion coating, characterized in that said apparatus comprises an extruding machine for extruding said thermoplastic rubber composition and said molecular-orientated thermoplastic resin composition, a crosshead for simultaneously coating said optical fiber with the extruded thermoplastic rubber composition and molecular-orientated thermoplastic resin composition to form said first and said second layer around said optical fiber, and first cooling means, having a length x(m) which satisfies the condition x/ V , 1 for a fiber travelling at a speed of V(m/sec), disposed on the outlet side of said crosshead for forcibly cooling the coated optical fiber at a liquid crystal transition temperature of the liquid crystalline thermoplastic resin composition of the second layer or less, and that said crosshead has at least a set of nipple and die, and an extreme end portion of said nipple, which is located inside said nozzle, forms a straight pipe having an inner diameter larger than the diameter of said optical fiber and less than 0.5 mm.
Claim 15
Independent Claim
264 words
An apparatus for fabricating a coated optical fiber wherein, immediately after spinning an optical fiber from an optical fiber preform by heating to soften said optical fiber preform, said optical fiber is coated with a first layer of a thermoplastic rubber compositon which has a Young's modulus of 0.1 GPa or less and is capable of extrusion coating and a second layer of a molecular-orientated thermoplastic resin composition which exhibits liquid crystallizability in molten state and which has a linear expansion coefficient of 7 x 10- 5 °C-' or less and a Young's modulus of 4.3 GPa or more and is capable of extrusion coating, characterized in that said apparatus comprises an extruding machine for extruding said thermoplastic rubber composition and said molecular-orientated thermoplastic resin composition, a crosshead for simultaneously coating said optical fiber with the extruded thermoplastic rubber composition and molecular-orientated thermoplastic resin composition to form said first and said second layer around said optical fiber, and first cooling means, having a length x(m) which satisfies the condition x/ V , 1 for a fiber travelling at a speed of V(m/sec), disposed on the outlet side of said crosshead for forcibly cooling the coated optical fiber at a liquid crystal transition temperature of the liquid crystalline thermoplastic resin composition of the second layer or less, and that said crosshead has at least a set of nipple and die, and an extreme end portion of said nipple, which is located inside said nozzle, forms a straight pipe having an inner diameter larger than the diameter of said optical fiber and less than 0.5 mm.
Claim 16
Dependent Claim
53 words
An apparatus for fabricating a coated optical fiber as claimed in claim 12, characterized in that said first layer and/or second layer coating materials are extruded into a gap defined between said nipple and said die, so that said optical fiber is coated with said coating materials in said nozzle of said die.
Claim 17
Dependent Claim
43 words
An apparatus for fabricating a coated optical fiber as claimed in claim 12, characterized in that the interior of said first cooling means is filled with coolant which is brought into contact with said coated optical fiber to cool said coated optical fiber.
Claim 18
Dependent Claim
52 words
An apparatus for fabricating a coated optical fiber as claimed in claim 14, characterizing by further comprising second means for cooling said coolant which is to be introduced into the interior of said first cooling means, and means for circulating said coolant between said first cooling means and said second cooling means.
References Cited (Backward Citations)
No citation records indexed.
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