Ethylene polymer pellet and extrusion process using the same

Patent metadata

Field	Value
Publication number	US-9644061-B2
Application number	US-201113583134-A
Country	US
Kind code	B2
Filing date	Mar 7, 2011
Priority date	Mar 8, 2010
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

Provided is a pellet of an ethylene polymer having a kneading torque at 160° C. of 2 to 15 Nm, wherein the pellet has a specific surface area of 1,800 to 3,000 mm 2 /g.

First claim

The invention claimed is:

1. A process for preparing an extruded product comprising
(a)(1) feeding a pellet of an ethylene α-olefin copolymer and a liquid into a hopper to a single screw extruder, and mixing the pellet and the liquid together in the hopper, wherein the ethylene-α-olefin copolymer exhibits a kneading torque of 2 to 15 Nm at 160° C. and the pellet has a specific surface area of 1800 to 3000 mm 2 /g, or
(a)(2) mixing a pellet of an ethylene-α-olefin copolymer and a liquid together and bringing them into contact with each other before feeding them into a hopper of a single screw extruder, and then feeding them into the hopper to a single screw extruder, wherein the ethylene-α-olefin copolymer exhibits a kneading torque of 2 to 15 Nm at 160° C. and the pellet has a specific surface area of 1800 to 3000 mm 2 /g;
(b) kneading them in the single-screw extruder to form a kneaded material; and
(c) extruding the kneaded material through a die to obtain the extruded product.

2. The process according to claim 1 , wherein the liquid is an alkoxysilane.

3. The process according to claim 1 , wherein the liquid comprises an alkoxysilane and a radical generator.

4. The process according to claim 2 , wherein the alkoxysilane is vinyltrimethoxysilane.

5. The process according to claim 3 , wherein the radical generator is dicumyl peroxide.

6. The process according to claim 1 , wherein the ethylene-α-olefin copolymer has an EP index of 0.1 to 1 calculated by the following method:
EP index=( MT 190)/( B torque),

wherein
MT190 (unit cN) is a melt tension at 190° C., and
B torque (unit: Nm) is a kneading torque at 160° C.

7. The process according to claim 6 , wherein the EP index is not less than 0.3.

8. The process according to claim 6 , wherein the EP index is not less than 0.4.

9. The process according to claim 6 , wherein the EP index is (a) not less than 0.5; (b) not more than 0.7, (c) not more than 0.8; or (d) not more than 0.9.

10. The process according to claim 1 , wherein the pellet has a specific surface area of 1800 to 2800 mm 2 /g.

11. The process according to claim 1 , wherein the pellet has a specific surface area of 1800 to 2600 mm 2 /g.

12. The process according to claim 1 , wherein the pellet has a specific surface area of (a) 2237 mm 2 /g; or (b) a specific surface area of 2237 to 2303 mm 2 /g.

13. The process according to claim 1 , wherein the pellet has a surface area of 20 to 60 mm 2 .

14. The process according to claim 13 , wherein the pellet has a surface area of (a) not less than 30 mm 2 ; or (b) not less than 40 mm 2 .

15. The process according to claim 14 , wherein the pellet has a surface area of not more than 58 mm 2 .

16. The process according to claim 6 , wherein the at least one pellet has a surface area of 20 to 60 mm 2 ; the amount of the liquid is 0.01 to 10 parts by weight relative to 100 parts by weight of the pellet; and the liquid comprises an alkoxysilane and, optionally, a radical generator.

17. The process according to claim 1 , wherein said process is conducted with (a)(1) feeding a pellet of an ethylene-α-olefin copolymer and a liquid into a hopper to a single screw extruder, and mixing the pellet and the liquid together in the hopper, wherein the ethylene-α-olefin copolymer exhibits a kneading torque of 2 to 15 Nm at 160° C. and the pellet has a specific surface area of 1800 to 3000 mm 2 /g.

18. The process according to claim 1 , wherein said process is conducted with (a)(2) mixing a pellet of an ethylene-α-olefin copolymer and a liquid together and bringing them into contact with each other before feeding them into a hopper of a single screw extruder, and then feeding them into the hopper to a single screw extruder, wherein the ethylene-α-olefin copolymer exhibits a kneading torque of 2 to 15 Nm at 160° C. and the pellet has a specific surface area of 1800 to 3000 mm 2 /g.

19. The process according to claim 1 , wherein the ethylene-α-olefin copolymer has a density of 860 kg/m 3 to 990 kg/m 3 .

20. The process according to claim 1 , wherein the ethylene-α-olefin copolymer has a melt flow rate of 0.01 g/10 min. to 100 g/10 min. measured at a temperature of 190° C. and a load of 21.18 N.

21. The process according to claim 1 , wherein the ethylene-α-olefin copolymer has a long chain branch and a short chain branch derived from an α-olefin.

Assignees

• Ejiri Susumu
• Sumitomo Chemical Co

Inventors

• Ejiri Susumu

Classifications

• B29K2023/06

  PE, i.e. polyethylene · CPC title

• C08K5/14

  Peroxides · CPC title

• C08K5/5425

  containing at least one C=C bond · CPC title

• B29K2023/00

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

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title