Process and apparatus for the production of an elastomeric optical conductor fiber and optical conductor fiber

• US 8,515,229 B2
• Filed: 07/25/2008
• Issued: 08/20/2013
• Est. Priority Date: 07/28/2007
• Status: Active Grant

• Current Assignee: Leoni Bordnetz-Systeme GmbH (Leoni AG)
• Original Assignee: Leoni Bordnetz-Systeme GmbH (Leoni AG)
• Inventors: Reichinger, Gerhard, Streit, Simone, Stallwitz, Markus, Schipke, Stefan
• Primary Examiner(s): Le, Uyen Chau N
• Assistant Examiner(s): Smith, Chad
• Application Number:
  US12/671,170
• Publication Number:
  US 20100329629A1
• Time in Patent Office: 1,852 Days
• Field of Search: 653/85, 264/1.29
• US Class Current: 385/100
• CPC Class Codes: B29C 2035/043 oil
• CPC Class Codes: B29C 35/065 in long tubular vessels
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/154 Coating solid articles, i.e. non-hollow articles
• CPC Class Codes: B29C 48/34 Cross-head annular extrusion nozzles, i.e. for simultaneously receiving moulding material and the preform to be coated
• CPC Class Codes: B29C 48/91 Heating, e.g. for cross linking
• CPC Class Codes: B29D 11/00663 Production of light guides

Abstract

A method of producing an elastomeric optical conductor fiber composed of plastic includes drawing a fiber composed of a high-viscosity liquid reactive starting material. The starting material is added by way of a nozzle to a reaction apparatus, to which a liquid, which is inert towards the starting material, has been charged. At least partial crosslinking of the starting material takes place in the reaction apparatus. The elastomeric plastic of the optical conductor fiber is in particular a three-dimensionally crosslinked polyurethane.

Claims

1. A method of producing an elastomeric optical fiber, the method which comprises:

mixing a plurality of reactive starting components in a predetermined composition in a metering device to form a viscous reactive starting material formed of first component (A1) made up of 98.34% by weight of a trivalent polyol based on polycaprolactone, 1.1% by weight of an additive component, and 0.55% by weight of a catalyst, and of a second component being a commercially available polyisocyanate with an NCO content of 22%;

providing a reaction device containing a liquid that is inert with respect to the reactive starting material;

passing the viscous reactive starting material to and through a nozzle die to form a fiber from the reactive starting material, and guiding the fiber into the reaction device;

cooling the reactive starting material until the starting material reaches the reaction device, and at least partially crosslinking the starting material in the reaction device.

2. The method according to claim 1, wherein the starting material moves downward in the reaction device under its own weight over a drop height of several meters and the starting material is slowed down by the liquid.

3. The method according to claim 1, which comprises tempering the liquid.

4. The method according to claim 1, wherein the liquid is an oil with a lower density than a density of the starting material.

5. The method according to claim 1, which comprises, after partial crosslinking, actively drawing the fiber to a desired final diameter.

6. The method according to claim 1, which comprises drawing the fiber through a diaphragm in an end region of the reaction device and the diaphragm is adapted to the diameter of the fiber.

7. The method according to claim 6, wherein the diaphragm can be dynamically set.

8. The method according to claim 6, wherein the diaphragm comprises an elastically deformable tube that can be subjected to pressure from the outside and that lies against the fiber.

9. The method according to claim 6, which comprises providing a belt drawing device having counter-circulating belts with a smooth surface following the diaphragm, and gripping the fiber between the belts and drawing the fiber.

10. The method according to claim 1, which comprises, following the reaction device, post-crosslinking the partially crosslinked fiber and cleaning the fiber, and thereby selecting one or a combination of the following steps:

drawing the fiber through a heated bath for further crosslinking;

drawing the fiber through a heated cleaning device for cleaning;

rinsing the fiber in the cleaning device by continuous circulation of a rinsing liquid, and optionally exposing the fiber to the effect of ultrasound;

drying the fiber under negative pressure; and

storing the fiber until complete crosslinking occurs.

11. The method for producing an optical fiber according to claim 1, the method which comprises:

drawing the fiber from the viscous reactive starting material and shaping the starting material by way of the nozzle die; and

introducing laser light longitudinally into the nozzle die and thereby crosslinking the starting material with the aid of the laser light to form an plastic fiber.

12. The method for producing an optical fiber according to claim 1, which comprises:

providing the viscous starting material in the form of a reactive, spatially crosslinkable polyurethane system, namely a 2-component system with a polyol and a polyisocyanate as a crosslinking agent, the crosslinking taking place by way of a polyaddition reaction of the functional group of the polyol with the functional group of the polyisocyanate and a molar ratio of the functional groups NCO;

OH lying in the range between 1.3;

1 and 0.9;

1; and

drawing the fiber from the viscous reactive starting material and crosslinking the starting material.

13. The method according to claim 12, which comprises setting the molar ratio of the functional groups NCO:

OH at 1.1;

1.

14. A method of producing an optical fiber from plastic, which comprises:

providing a viscous starting material in the form of a reactive, spatially crosslinkable polyurethane system, namely a 2-component system with a polyol and a polyisocyanate as a crosslinking agent, the 2-component system having a first component (A1) made up of 98.34% by weight of a trivalent polyol based on polycaprolactone, 1.1% by weight of an additive component, and 0.55% by weight of a catalyst, and a second component that is a commercially available polyisocyanate with an NCO content of 22%, the crosslinking taking place by way of a polyaddition reaction of the functional group of the polyol with the functional group of the polyisocyanate and a molar ratio of the functional groups NCO;

OH lying in the range between 1.3;

1 and 0.9;

1; and

drawing a fiber from the viscous reactive starting material and crosslinking the starting material.

15. The method according to claim 14, which comprises setting the molar ratio of the functional groups NCO:

OH at 1.1;

1.

16. The method according to claim 14, wherein the polyol is a trivalent alcohol based on a polycaprolactone.

17. The method according to claim 14, wherein the polyol is a mixture of low molecular weight polyols and higher molecular weight polyols.

18. The process is claimed in claim 14, which comprises formulating the components superstoichiometrically and admixing an additional reactive crosslinking agent.

19. The method according to claim 14, which comprises fluorinating a surface of the fiber.

20. The method according to claim 14, which comprises admixing a catalyst to speed up a crosslinking reaction.

21. The method according to claim 20, which comprises admixing the catalyst in a range from approximately 0.3 to 1% by weight with respect to a proportion of the polyol component.

22. The method according to claim 14, which comprises admixing an additive against thermo-oxidative degradation.

23. The method according to claim 22, which comprises admixing the additive in a range from approximately 1 to 5% by weight with respect to a proportion of the polyol component.

24. The method according to claim 14, which comprises blocking at least one component of the starting material prior to an onset of the crosslinking.

25. An optical fiber, comprising:

an elastomeric plastic in the form of a three-dimensionally crosslinked 2-component polyurethane system, the polyurethane system having a functional group of a polyol crosslinked in a polyaddition reaction with a functional group of a polyisocyanate, the 2-component polyurethane system including a first component (A1) made up of 98.34% by weight of a trivalent polyol based on polycaprolactone, 1.1% by weight of an additive component, and 0.55% by weight of a catalyst, and a second component being a commercially available polyisocyanate with an NCO content of 22%; and

wherein a molar ratio of the functional groups NCO;

OH lies in the range between 1.3;

1 and 0.9;

1.

26. The optical fiber according to claim 25, wherein said molar ratio of NCO:

OH is 1.1;

1.

27. The optical fiber according to claim 25 produced by the method according to claim 1.

28. The optical fiber according to claim 25, wherein said polyol is a trivalent alcohol based on a polycaprolactone.