Very thin tube made from TPU and its production process

Patent metadata

Field	Value
Publication number	US-11285651-B2
Application number	US-201615574501-A
Country	US
Kind code	B2
Filing date	May 12, 2016
Priority date	May 20, 2015
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

The present invention is directed to a process for the preparation of a tube with an outer diameter in the range of from 10 μm to 250 μm consisting of a composition comprising a thermoplastic polyurethane as well as to a tube with an outer diameter in the range of from 10 μm to 250 μm consisting of a composition comprising a thermoplastic polyurethane obtained or obtainable by the process according to the invention. The invention is further directed to the use of a tube according to the invention as a tube for the transportation of a fluid or as gas membrane tube or as an elastic fiber.

First claim

The invention claimed is:

1. A process for preparing at least one tube with an outer diameter of from 10 μm to 250 μm comprising a thermoplastic polyurethane, the process comprising
(i) melting a thermoplastic polyurethane in an extruder at a temperature of 160° C. to 230° C. to obtain a molten thermoplastic polyurethane;
(ii) to the molten thermoplastic polyurethane, adding a composition comprising a cross linker comprising isocyanate groups to obtain a mixture and mixing the mixture to form a melt;
(iii) extruding the melt through a spinneret heated at 180° C. to 230° C. to obtain a melt-spun elastic tube;
(iv) cooling the melt spun elastic tube in a cooling section to obtain a cooled melt spun elastic tube; and
(v) contacting the cooled melt spun elastic tube with finish oil in a finishing section, the finish oil being selected from the group consisting of mineral oil and silicone oil;
wherein the extruder, the cooling section, and the finishing section are arranged in a vertical setting;
wherein the tube is round with a level of roundness of accuracy in 1 micron.

2. The process according to claim 1 , wherein the tube has soft stretch properties.

3. The process according to claim 1 , wherein the spinneret has more than one opening.

4. The process according to claim 3 , wherein said more than one opening are arc-like slots.

5. The process according to claim 1 , wherein the spinneret is heated to a temperature of from 180° C. to 230° C.

6. The process according to claim 1 , which is performed at a production line speed of greater than 500 m/min.

7. The process according to claim 1 , wherein 3 or more tubes are produced in parallel.

8. The process according to claim 1 , wherein the thermoplastic polyurethane has a shore hardness of from 60 A to 74 D, determined according to DIN 53505.

9. The process according to claim 1 , wherein the outer diameter of the tube ranges from 15 to 200 μm.

10. The process according to claim 1 , wherein a hollow ratio of the tube ranges from 5 to 50%.

11. The process according to claim 1 , wherein the cooled melt spun elastic tube is a single cooled melt spun elastic tube, and further comprising:
winding the single cooled melt spun elastic tube after the contacting onto a roll.

12. The process according to claim 1 , wherein the melt consists of the molten thermoplastic polyurethane and the crosslinker.

13. The process according to claim 1 , wherein the spinneret has a ring structure nozzle with concentrically positioned arc like slots.

Assignees

• Basf Se

Inventors

• Chen Bin-Erik
• Nomura Akira

Classifications

• D01F6/70

  from polyurethanes · CPC title

• B29C48/32

  with annular openings, e.g. for forming tubular articles · CPC title

• D01D5/24

  with a hollow structure; Spinnerette packs therefor (D01D5/38 takes precedence; producing tubes of plastic material B29D; addition of agents forming hollow filaments D01F1/08) · CPC title

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title

• B01D2325/24

  Mechanical properties, e.g. strength · CPC title