Small diameter polyolefin fibers

Patent metadata

Field	Value
Publication number	US-2016177473-A1
Application number	US-201414905869-A
Country	US
Kind code	A1
Filing date	Sep 19, 2014
Priority date	Sep 19, 2013
Publication date	Jun 23, 2016
Grant date	—

Abstract

Prepare a polyolefin fiber having a diameter of 10 microns or less by extruding a molten polyolefin through die holes having diameters in a range of 250 to 500 microns to produce molten polyolefin fibers; drawing the molten polyolefin fibers to achieve a molten draw ratio in a range of 150 to 500 at a temperature in a range of 200 to 250 degrees Celsius; and drawing the polyolefin fibers in a solid state to achieve a solid state draw ratio of 3.0 to 4.0 at a temperature in a range of 40 to 100 degrees Celsius to produce polyolefin fibers having a diameters of 10 microns or less; where the polyolefin is characterized by being a polyolefin copolymer of ethylene and one or more than one alpha-olefin and where the copolymer has a solid density of 0.870 or more and 0.96 or less as determined according to ASTM D792.

First claim

What is claimed is:

1 . A process comprising:
(a) extruding a molten polyolefin through die holes of a die where the die hole diameters are in a range of 250 to 500 microns to produce fibers of molten polyolefin; (b) drawing the fibers of molten polyolefin to an extent characterized by a molten draw ratio in a range of 150 to 500 at a temperature in a range of 200 to 250 degrees Celsius; and (c) drawing the polyolefin fibers in a solid state to an extent characterized by a solid state draw ratio of 3.0 to 4.0 at a temperature in a range of 40 to 100 degrees Celsius to produce polyolefin fibers having a diameters of 10 microns or less;
where the polyolefin is characterized by being a polyolefin copolymer of ethylene and one or more than one alpha-olefin and where the copolymer has a solid density of 0.870 or more and 0.96 or less as determined according to ASTM D792.

2 . The process of claim 1 , further characterized by the polyolefin fibers have a diameter of one micron more and 10 microns or less after drawing in the solid state during step (c).

3 . The process of claim 1 , further characterized by each of steps (a), (b) and (c) occurring in a single continuous process.

4 . The process of claim 1 , further characterized by chemically modifying the polyolefin fiber produced in step (c) so as to produce a stabilized polyolefin fiber having a diameter of 10 microns or less.

5 . The process of claim 1 , further characterized by sulfonating the polymer fiber after step (c) so as to produce sulfonated fibers having a diameter of 10 microns or less.

6 . The process of claim 1 where the alpha-olefin is selected from a group consisting of 1-butene, 1-hexene and 1-octene.

7 . The process of claim 4 , further comprising heating the stabilized polyolefin fiber to produce a carbon fiber by carbonizing the stabilized polyolefin fiber.

8 . A polyolefin fiber comprising a polyolefin copolymer of ethylene and one or more than one alpha-olefin and where the polyolefin copolymer has a solid density of 0.87 or more and 0.96 or less as determined according to ASTM D792 and wherein the fiber has a diameter of 10 microns or less.

9 . The polyolefin fiber of claim 8 , further characterized by the alpha-olefin being selected from a group consisting of 1-butene, 1-hexene and 1-octene.

10 . The polyolefin fiber of claim 8 , further characterized by being chemically stabilized.

11 . The polyolefin fiber of claim 10 , further characterized by being sulfonated.

Assignees

• Dow Global Technologies Llc

Inventors

• Spalding Mark A
• Wang Weijun
• Pavlicek Calvin L
• Horstman Nicholas J

Classifications

• B29K2023/00

  Use of polyalkenes {or derivatives thereof} as moulding material · CPC title

• D01D5/098

  with simultaneous stretching · CPC title

• D01F6/30 Primary

  comprising olefins as the major constituent · CPC title

• B29C47/0057

  Operations & Transport · mapped topic

• B29C47/0014

  Operations & Transport · mapped topic