Gel extruded articles made from high-density polyethylene with a narrow molecular weight distribution

Abstract

The present invention provides polymers and polymer formulations that improve the mechanical properties, such as strength characteristics, of gel extruded articles. [Solution] A polymer composition for producing gel extruded articles contains polyethylene particles combined with a plasticizer. The polyethylene polymer has a narrow molecular weight distribution. Polymer articles produced according to this disclosure have improved strength properties. In one embodiment, the polymer composition is used to form a porous membrane for use as a separator in electronic devices.

Claims

1. A polymer composition for manufacturing gel extruded articles, Plasticizers and Polymer particles containing high-density polyethylene polymer and Includes, The high-density polyethylene polymer has a narrow molecular weight distribution such that the polydispersity index (PDI) is less than about 8. Polymer composition.

2. The polymer composition according to claim 1, wherein the high-density polyethylene polymer has an intersection point (ICP) with a pressure of more than about 150 kPa, for example, more than about 160 kPa, for example, more than about 165 kPa.

3. The polymer composition according to claim 1 or 2, wherein the high-density polyethylene polymer has a polydispersity index (PDI) of less than about 7.5, for example, less than 7.

4. The polymer composition according to any one of claims 1 to 3, wherein the high-density polyethylene polymer has an intersection point (ICP) greater than about 168 kPa and a polydispersity index (PDI) of less than about 6.

5.

5. The polymer composition according to any one of claims 1 to 4, wherein the high-density polyethylene particles have a volume median particle size of about 70 microns to about 210 microns.

6. The polymer composition according to any one of claims 1 to 5, wherein the high-density polyethylene particles are present in the composition in an amount of up to about 50% by weight.

7. The polymer composition according to any one of claims 1 to 6, wherein the plasticizer comprises mineral oil, paraffinic oil, hydrocarbon, alcohol, ether, ester, or a mixture thereof.

8. The polymer composition according to any one of claims 1 to 7, wherein the high-density polyethylene has a molecular weight of more than about 400,000 g / mol, for example more than about 500,000 g / mol, for example more than about 600,000 g / mol, for example more than about 700,000 g / mol, and a molecular weight of less than about 4,000,000 g / mol, for example less than about 3,500,000 g / mol.

9. The polymer composition according to claim 8, comprising only a single high-density polyethylene polymer.

10. The polymer composition according to any one of claims 1 to 9, wherein the high-density polyethylene has a molecular weight greater than about 500,000 g / mol and less than about 1,500,000 g / mol.

11. The polymer composition according to any one of claims 1 to 10, wherein the plasticizer comprises decalin, paraffin oil, white oil, mineral oil, xylene, dioctyl phthalate, dibutyl phthalate, stearyl alcohol, oleyl alcohol, decyl alcohol, nonyl alcohol, diphenyl ether, n-decane, n-dodecane, octane, nonane, kerosene, toluene, naphthalene, tetralin, monochlorobenzene, camphene, methane, dipentene, methylcyclopentanediene, tricyclodecane, 1,2,4,5-tetramethyl-1,4-cyclohexadiene, or a mixture thereof.

12. A polymer composition according to any one of claims 1 to 11, which does not contain polypropylene.

13. The polymer composition according to any one of claims 1 to 12, wherein the high-density polyethylene polymer is catalyzed with a Ziegler-Natta catalyst.

14. A molded article formed from a polymer composition according to any one of claims 1 to 13, wherein the plasticizer is contained in an amount of less than about 2% by weight, for example, less than about 1% by weight.

15. A molded article according to claim 14, comprising a film or fiber.

16. A product incorporating a molded article according to claim 14 or 15, including bulletproof cloth, gloves, rope, fishing line, or clothing.

17. A method for manufacturing polymer articles, A step of forming a gel-like composition from a polymer composition according to any one of claims 1 to 13, The steps include: extruding the gel-like composition through a die to form a polymer article; Includes, The polymer article includes a film. method.

18. The method according to claim 17, further comprising the step of removing at least a portion of the plasticizer from the polymer article.

19. The method according to claim 17 or 18, wherein an extraction solvent is added to the polymer composition during the method to facilitate the removal of the plasticizer from the polymer article.

20. The method according to claim 19, wherein the extraction solvent comprises dichloromethane, acetone, chloroform, alkanes, hexene, heptene, alcohols, or mixtures thereof.

21. A porous membrane, A porous membrane comprising high-density polyethylene having a polydispersity index (PDI) of less than approximately 8, wherein the high-density polyethylene polymer is catalyzed with a Ziegler-Natta catalyst, the high-density polyethylene has a molecular weight greater than approximately 400,000 g / mol and less than approximately 900,000 g / mol, and the porous membrane has a tensile strength greater than approximately 90 MPa in at least one direction and a puncture strength greater than approximately 500 mN / μm.

22. The porous membrane according to claim 21, having a thickness of approximately 7 microns to approximately 11 microns, for example, approximately 7.5 microns to approximately 10 microns.

23. A porous membrane according to claim 21 or 22, having a Guarley permeability of more than approximately 105 seconds / 100 ml.

24. The porous membrane according to claim 21, 22, or 23, having a puncture strength of more than approximately 700 mN / μm, for example, more than approximately 800 mN / μm.

25. A porous membrane according to claim 21, 22, 23, or 24, which is biaxially stretched.

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