Ethylene-α-olefin copolymer and olefin resin composition

Patent metadata

Field	Value
Publication number	US-10066036-B2
Application number	US-201515128201-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	Mar 31, 2014
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

[Problem] To provide an ethylene-α-olefin copolymer that is highly effective in improving the molding properties of polyolefin resins, improving the balance between impact strength and stiffness, and improving transparency. [Solution] Provided is an ethylene-α-olefin copolymer having a specific MFR, a specific density, and a specific molecular weight distribution, containing a suitable amount of a long-chain branching structure characterized by a branching index, and having a specific composition distribution structure characterized by solvent fractionation behavior.

First claim

The invention claimed is:

1. An ethylene-α-olefin copolymer satisfying the following conditions (1), (2), (5), and (7):
(1) the copolymer has a MFR of 0.001 to 0.1 g/10 minutes;
(2) the copolymer has a density of not less than 0.895 g/cm 3 but less than 0.918 g/cm 3 ;
(5) the copolymer has a minimum branching index (gc) of 0.40 to 0.85 as measured for branching index g′ in the molecular weight range of 100,000 to 1,000,000 with a GPC measurement system comprising a combination of a differential refractometer, a viscosity detector, and a light scattering detector; and
(7) the copolymer has a sum (W 2 +W 3 ) of a content (W 2 ) and a content (W 3 ) of more than 40% by weight but less than 80% by weight, wherein W 2 is a content of components with molecular weights equal to or more than a weight average molecular weight in components eluted at temperatures equal to or lower than a temperature where an eluted amount determined from an integral elution curve measured by cross fractionation chromatography (CFC) is 50 wt %, and W 3 is a content of components with molecular weights less than the weight average molecular weight in components eluted at temperatures higher than the temperature where the eluted amount determined from the integral elution curve is 50 wt %;
wherein MFR is measured under the conditions of 190° C. and a load of 21.18 N (2.16 kg).

2. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (1′):
(1′) the copolymer has a MFR of 0.005 to 0.1 g/10 minutes.

3. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (2′):
(2′) the copolymer has a density of 0.898 to 0.915 g/cm 3 .

4. The ethylene-α-olefin copolymer according to claim 1 , wherein the α-olefin has three to ten carbon atoms.

5. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (3):
(3) the copolymer has a molecular weight distribution Mw/Mn of 3.0 to 7.0 as measured by gel permeation chromatography (GPC).

6. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (4):
(4) the copolymer has a molecular weight distribution Mz/Mw of 2.0 to 7.0 as measured by GPC.

7. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (6):
(6) a content (X) of components eluted at 85° C. or higher by temperature rising elution fractionation (TREF) is 0 to 15% by weight.

8. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (8):
(8) the copolymer has a sum (W 2 +W 4 ) of W 2 and a content (W 4 ) of more than 29% by weight but less than 50% by weight, wherein W 4 is a content of components with molecular weights equal to or more than the weight average molecular weight in components eluted at temperatures higher than the temperature where the eluted amount determined from the integral elution curve measured by CFC is 50 wt %.

9. The ethylene-α-olefin copolymer according to claim 1 , further satisfying the following condition (9):
(9) the copolymer has a difference (W 2 −W 4 ) between W 2 and W 4 of more than −5% by weight but less than 30% by weight.

10. A method for producing the ethylene-α-olefin copolymer according to claim 1 , the method comprising producing the ethylene-α-olefin copolymer using an olefin polymerization catalyst comprising the following components (A), (B) and (C):
(A) a bridged cyclopentadienyl indenyl compound containing a transition metal element;
(B) a compound capable of reacting with the compound of the component (A) to form a cationic metallocene compound; and
(C) an inorganic compound carrier.

11. The method for producing the ethylene-α-olefin copolymer according to claim 10 , wherein a ratio of number of moles of a metal in the component (B) to 1 g of the component (C) is 0.001 to 0.020 (moles/g).

12. A method for producing the ethylene-α-olefin copolymer according to claim 1 , the method comprising copolymerizing ethylene and an α-olefin by a gas phase method or a slurry method.

13. An olefin resin composition comprising: the ethylene-α-olefin copolymer (A) according to claim 1 ; and one or more other olefin resins.

14. The olefin resin composition according to claim 13 , wherein an amount of the ethylene-α-olefin copolymer (A) contained in the resin composition is 1 to 59% by weight.

15. The olefin resin composition according to claim 13 , which comprises an additional ethylene-α-olefin copolymer (B) other than the copolymer (A) as an olefin resin other than the copolymer (A).

16. The olefin resin composition according to claim 15 , wherein the additional ethylene-α-olefin copolymer (B) satisfies the following conditions (B-1) and (B-2):
(B-1) the copolymer (B) has a MFR of 0.01 to 20 g/10 minutes; and
(B-2) the copolymer (B) has a density of 0.880 to 0.970 g/cm 3 .

17. The olefin resin composition according to claim 16 , wherein the additional ethylene-α-olefin copolymer (B) further satisfies the following condition (B-3):
(B-3) [Mw/Mn]=2.0 to 4.0.

18. The olefin resin composition according to claim 13 , wherein polymers satisfying at least one of the following conditions are used as the ethylene-α-olefin copolymer (A) and the ethylene-α-olefin copolymer (B):
(AB-1) MFR B >MFR A ; and
(AB-2) [Mw/Mn] B <[Mw/Mn] A ,
wherein MFR A represents MFR of the ethylene-a-olefin copolymer (A), [Mw/Mn] A represents Mw/Mn of the ethylene-α-olefin copolymer (A), MFR B represents MFR of the ethylene-α-olefin copolymer (B), and [Mw/Mn] B represents Mw/Mn of the ethylene-α-olefin copolymer (B).

19. The olefin resin composition according to claim 13 , wherein the ethylene-α-olefin copolymer (B) is linear low-density polyethylene having a MFR of not less than 0.1 but less than 5.0 and produced with a Ziegler catalyst or metallocene polyethylene having a MFR of not less than 0.1 but not more than 10 and produced with a metallocene catalyst.

20. A film obtained from the ethylene-α-olefin copolymer according to claim 1 .

Assignees

• Japan Polyethylene Corp

Inventors

• Ishihama Yoshiyuki
• Harada Ryotaro
• Aoki Masaru
• Iiba Kenji
• Kodama Kazushi
• Hayashi Hiroto

Classifications

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L23/0815

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F2/34

  Polymerisation in gaseous state · CPC title

• C08J2423/08

  Copolymers of ethene (C08J2423/16 takes precedence) · CPC title