Polyethylene compositions and films formed therefrom

Patent metadata

Field	Value
Publication number	US-9988505-B2
Application number	US-201514924302-A
Country	US
Kind code	B2
Filing date	Oct 27, 2015
Priority date	Oct 27, 2014
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A polyethylene composition comprising an ethylene/α-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.

First claim

What is claimed is:

1. A polyethylene composition comprising an ethylene/α-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw ranging from 100,000 g/mol to 200,000 g/mol, a Mw/Mn ranging from 4.0 to 9.0, a Mz/Mw ranging from 4.0 to 7.0, and a Mz+1/Mw ranging from 4.5 to 13.5, wherein said Mw, Mn, Mz, Mz+1 are measured by gel permeation chromatography.

2. The polyethylene composition of claim 1 , wherein the polyethylene composition has a Mw ranging from 100,000 g/mol to 180,000 g/mol, a Mw/Mn ranging from 4.0 to 8.5, a Mz/Mw ranging from 4.0 to 6.5, and a Mz+1/Mw ranging from 4.5 to 12.5.

3. The polyethylene composition of claim 2 , having at least one of the following features (a)-(d):
(a) the polyethylene composition has such a temperature rising elution curve, obtained by analytical temperature rising elution fractionation method, that comprises a high-temperature eluting peak and a low-temperature eluting peak, wherein the high-temperature eluting peak is at a temperature ranging from 90 to 105° C., and the low-temperature eluting peak is at a temperature ranging from 50 to 90° C., and wherein the area of the high-temperature eluting peak accounts for no more than 60% of the total area of the high-temperature eluting peak and the low-temperature eluting peak, and the area of the low-temperature eluting peak accounts for at least 40% of the total area of the high-temperature eluting peak and the low-temperature eluting peak;
(d) the polyethylene composition has a melting temperature, measured by differential scanning calorimetry, ranging from 100 to 130° C.;
(c) the linear low density polyethylene has a molar content of the α-olefin comonomer ranging from 0.5 mol % to 20 mol %; and
(d) the polyethylene composition has a melt index ranging from 0.1 to 20 g/10 min, measured at 190° C. under 2.16 kg load.

4. The polyethylene composition of claim 2 , having at least one of the following features (a)-(d):
(a) the polyethylene composition has such a temperature rising elution curve, obtained by analytical temperature rising elution fractionation method, that comprises a high-temperature eluting peak and a low-temperature eluting peak, wherein the high-temperature eluting peak is at a temperature ranging from 95 to 100° C., and the low-temperature eluting peak is at a temperature ranging from 60 to 90° C., and wherein the area of the high-temperature eluting peak accounts for no more than 50% of the total area of the high-temperature eluting peak and the low-temperature eluting peak, and the area of the low-temperature eluting peak accounts for at least 50% of the total area of the high-temperature eluting peak and the low-temperature eluting peak;
(b) the polyethylene composition has a melting temperature, measured by differential scanning calorimetry, ranging from 105 to 128° C.;
(c) the linear low density polyethylene has a molar content of the α-olefin comonomer ranging from 2 mol % to 10 mol %; and
(d) the polyethylene composition has a melt index ranging from 0.5 to 10 g/10 min, measured at 190° C. under 2.16 kg load.

5. The polyethylene composition of claim 2 , wherein the polyethylene composition comprises component A, component C, and optionally component B, wherein the component A comprises an ethylene/α-olefin copolymerized linear low density polyethylene having a melt index MI A ranging from 0.01 to 2 g/10 min and a density ρ A ranging from 0.880 to 0.936 g/cm 3 ; the component B comprises an ethylene/α-olefin copolymerized linear low density polyethylene having a melt index MI B ranging from 2.1 to 9.9 g/10 min and a density ρ B ranging from 0.910 to 0.930 g/cm 3 ; and the component C comprises an ethylene/α-olefin copolymerized linear low density polyethylene having a melt index MI C ranging from 10 to 80 g/10 min and a density ρ C ranging from 0.880 to 0.930 g/cm 3 .

6. The polyethylene composition of claim 5 , having at least one of the following features (a)-(g):
(a) the component A has a melt index MI A ranging from 0.01 to 1.5 g/10 min, the component B has a melt index MI B ranging from 3 to 8 g/10 min, and the component C has a melt index MI C ranging from 10 to 60 g/10 min;
(b) the component A has a density ρ A ranging from 0.910 to 0.930 g/cm 3 , the component B has a density ρ B ranging from 0.913 to 0.928 g/cm 3 , and the component C has a density ρ C ranging from 0.905 to 0.928 g/cm 3 ;
(c) the densities ρ A , ρ B and ρ C of the components A, B and C satisfy: −0.04≤ρ A −ρ B ≤0.02 and −0.04≤ρ A −ρ C ≤0.02;
(d) the component A and the component B have, each independently, a molecular weight distribution index M w /M n of no more than 4.5, and the component C has a molecular weight distribution index M w /M n of no more than 8.0;
(e) the component A and the component B each are produced by polymerization using a metallocene catalyst, and the component C is produced by polymerization using a Ziegler-Natta catalyst;
(f) the α-olefins of the components A, B and C are, each independently, at least one chosen from C 3 -C 20 olefins; and
(g) the components A, B and C have, each independently, a molar content of the α-olefin ranging from 0.2 to 15 mol %.

7. The polyethylene composition of claim 5 , wherein in the polyethylene composition, the amount of component A, W A , ranging from 25-90 parts by weight, the amount of component B, W B , ranges from 0.1-10 parts by weight, and the amount of component C, W C , ranges from 10-75 parts by weight.

8. The polyethylene composition of claim 7 , wherein in the polyethylene composition, the amount of component A ranges from 30-80 parts by weight, the amount of component B ranges from 0.5-8 parts by weight, and the amount of component C ranges from 20-70 parts by weight.

9. The polyethylene composition of claim 7 , wherein the amount W A , the amount W C , and the melt index MI A satisfy: 5.2×lgMI A +11.6≥W A /W C ≥0.9×lgMI A +2.1.

10. The polyethylene composition of claim 7 , wherein the amount W A , the amount W C , and the melt index MI A satisfy: 2.9×lgMI A +6.8≥W A /W C ≥1.1×lgMI A +2.7.

11. The polyethylene composition of claim 7 , wherein the amount of component B is no more than 35 wt %, based on the total weight of the polyethylene composition.

12. The polyethylene composition of claim 1 , wherein the polyethylene composition has a Mw ranging from 100,000 g/mol to 180,000 g/mol, a Mw/Mn ranging from 4.0 to 8.0, a Mz/Mw ranging from 4.0 to 6.0, and a Mz+1/Mw ranging from 4.5 to 12.5.

13. The polyethylene composition of claim 12 , having at least one of the following features (a)-(d):
(a) the polyethylene composition has such a temperature rising elution curve, obtained by analytical temperature rising elution fractionation method, that comprises a high-temperature eluting peak and a low-temperature eluting peak, wherein the high-temperature eluting peak is at a temperature ranging from 90 to 105° C., and the low-temperature eluting peak is at a temperature ranging from 50 to 90° C., and wherein the area of the high-temperature eluting peak accounts for no more than 60% of the total area of the high-temperature eluting peak and the low-temperature eluting peak, and the area of the low-temperature eluting peak accounts for at least 40% of the total area of the high-temperature eluting peak and the low-temperature eluting peak;
(b) the polyethylene composition has a melting temperature, measured by differential scanning calorimetry, ranging from 100 to 130° C.;
(c) the linear low density polyethylene has a molar content of the α-olefin comonomer ranging from 0.5 mol % to 20 mol %; and
(d) the polyethylene composition has a m

Assignees

• China Petroleum & Chem Corp
• Beijing Res Inst Chemical Ind China Petroleum & Chemical Corp
• Beijing Res Institute Of Chemical Industry China Petroleum And Chemical Corporation

Inventors

• Gao Dali
• Shi Hongwei
• Zhang Shijun
• Guo Meifang
• Yu Luqiang
• Qiao Jinliang
• Li Ruxian
• Tang Yujing
• Yin Jianjun
• Wang Liangshi
• Huang Honghong
• Yang Qingquan
• Zou Hao
• Li Jie
• Zhang Liying
• Yin Hua
• Liu Jianye
• Shao Jingbo
• Lyu Mingfu
• Chu Liqiu
• Xu Meng
• Quan Hui
• Xu Kai
• Dong Mu
• Lyu Yun
• Xu Yihui
• Xu Yaohui
• Guo Peng
• Bai Yiqing

Classifications

• B32B2410/00

  Agriculture-related articles · CPC title

• C08L23/08

  Copolymers of ethene (C08L23/16 takes precedence) · CPC title

• B32B2307/406

  Bright, glossy, shiny surface · CPC title

• C08L2203/30

  used for thermoforming · CPC title

• C08J2323/08

  Copolymers of ethene (C08J2323/16 takes precedence) · CPC title