Ultrahigh-molecular-weight polyethylene powder

Patent metadata

Field	Value
Publication number	US-11623981-B2
Application number	US-201917041565-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Mar 27, 2018
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

The ultrahigh-molecular-weight polyethylene powder of the present invention is an ultrahigh-molecular-weight polyethylene powder having a viscosity-average molecular weight Mv of 10×104 or higher and 1000×104 or lower, wherein viscosity-average molecular weight Mv(A) of a kneaded product obtained by kneading under specific kneading conditions, and the Mv satisfy the following relationship: “{Mv−Mv(A)}/Mv is 0.20 or less”, and the ultrahigh-molecular-weight polyethylene powder contains an ultrahigh-molecular-weight polyethylene powder having a particle size of 212 μm or larger, wherein the powder having a particle size of 212 μm or larger has an average pore volume of 0.6 ml/g or larger and an average pore size of 0.3 μm or larger.

First claim

The invention claimed is:

1. An ultrahigh-molecular-weight polyethylene powder having a viscosity-average molecular weight Mv of 10×10 4 or higher and 1000×10 4 or lower, wherein
viscosity-average molecular weight Mv(A) of a kneaded product obtained by kneading under kneading conditions given below and the Mv satisfy the following relationship:
{ Mv−Mv ( A )}/ Mv is 0.20 or less, and

the ultrahigh-molecular-weight polyethylene powder contains an ultrahigh-molecular-weight polyethylene powder having a particle size of 212 μm or larger, wherein ultrahigh-molecular-weight polyethylene the powder having a particle size of 212 μm or larger has an average pore volume of 0.6 ml/g or larger and an average pore size of 0.3 μm or larger:
[kneading conditions for obtaining the kneaded product having viscosity-average molecular weight Mv(A)]

raw material:
a mixture containing 5 parts by mass of the ultrahigh-molecular-weight polyethylene powder and 95 parts by mass of liquid paraffin, and further 1 part by mass of an antioxidant per 100 parts by mass in total of the ultrahigh-molecular-weight polyethylene powder and the liquid paraffin, and conditions:
the raw material is kneaded at 130° C. for 30 minutes and then further kneaded at 240° C. for 15 minutes;
the heating rate from 130° C. to 240° C. is set to 22° C./min;
the number of screw rotations is set to 50 rpm; and
the kneading is performed in the nitrogen atmosphere.

2. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein a proportion of an ultrahigh-molecular-weight polyethylene powder having a particle size of 53 μm or smaller is less than 40% by mass per 100% by mass of the ultrahigh-molecular-weight polyethylene powder.

3. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein a bulk density of the ultrahigh-molecular-weight polyethylene powder having a particle size of 212 μm or larger is 0.20 g/cm 3 or higher and 0.60 g/cm 3 or lower.

4. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein the ultrahigh-molecular-weight polyethylene powder has a magnesium content of 0.1 ppm or higher and 20 ppm or lower.

5. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein the ultrahigh-molecular-weight polyethylene powder has a titanium content of 0.1 ppm or higher and 5 ppm or lower.

6. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein the ultrahigh-molecular-weight polyethylene powder has an aluminum content of 0.5 ppm or higher and 10 ppm or lower.

7. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein the ultrahigh-molecular-weight polyethylene powder has a silicon content of 0.1 ppm or higher and 100 ppm or lower.

8. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein the ultrahigh-molecular-weight polyethylene powder has a chlorine content of 1 ppm or higher and 50 ppm or lower.

9. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein a content ratio between magnesium and titanium (Mg/Ti) is 0.1 or more and 10 or less.

10. The ultrahigh-molecular-weight polyethylene powder according to claim 1 , wherein a content ratio between aluminum and titanium (Al/Ti) is 0.1 or more and 20 or less.

11. A high-strength fiber comprising the ultrahigh-molecular-weight polyethylene powder according to claim 1 .

12. A microporous membrane for a secondary battery separator comprising the ultrahigh-molecular-weight polyethylene powder according to claim 1 .

13. The ultrahigh-molecular-weight polyethylene powder according to claim 2 , wherein a bulk density of the ultrahigh-molecular-weight polyethylene powder having a particle size of 212 μm or larger is 0.20 g/cm 3 or higher and 0.60 g/cm 3 or lower.

14. The ultrahigh-molecular-weight polyethylene powder according to claim 2 , wherein the ultrahigh-molecular-weight polyethylene powder has a titanium content of 0.1 ppm or higher and 5 ppm or lower.

15. The ultrahigh-molecular-weight polyethylene powder according to claim 3 , wherein the ultrahigh-molecular-weight polyethylene powder has a titanium content of 0.1 ppm or higher and 5 ppm or lower.

16. The ultrahigh-molecular-weight polyethylene powder according to claim 13 , wherein the ultrahigh-molecular-weight polyethylene powder has a titanium content of 0.1 ppm or higher and 5 ppm or lower.

17. The ultrahigh-molecular-weight polyethylene powder according to claim 2 , wherein the ultrahigh-molecular-weight polyethylene powder has an aluminum content of 0.5 ppm or higher and 10 ppm or lower.

18. The ultrahigh-molecular-weight polyethylene powder according to claim 3 , wherein the ultrahigh-molecular-weight polyethylene powder has an aluminum content of 0.5 ppm or higher and 10 ppm or lower.

19. The ultrahigh-molecular-weight polyethylene powder according to claim 5 , wherein the ultrahigh-molecular-weight polyethylene powder has an aluminum content of 0.5 ppm or higher and 10 ppm or lower.

20. The ultrahigh-molecular-weight polyethylene powder according to claim 15 , wherein the ultrahigh-molecular-weight polyethylene powder has an aluminum content of 0.5 ppm or higher and 10 ppm or lower.

Assignees

• Asahi Chemical Ind

Inventors

• Tsujimoto Koichi

Classifications

• C08L23/06 Primary

  Polyethylene · CPC title

• H01M50/411

  Organic material · CPC title

• H01M50/417

  Polyolefins · CPC title

• D01F6/04

  from polyolefins · CPC title

• H01M50/491

  Porosity · CPC title