High clarity low haze compositions

Patent metadata

Field	Value
Publication number	US-9309338-B2
Application number	US-201514733457-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	May 22, 2014
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A first embodiment which is a bimodal polymer having a weight fraction of a lower molecular weight (LMW) component ranging from about 0.25 to about 0.45, a weight fraction of a higher molecular weight (HMW) component ranging from about 0.55 to about 0.75 and a density of from about 0.931 g/cc to about 0.955 g/cc which when tested in accordance with ASTM D1003 using a 1 mil test specimen displays a haze characterized by equation: % Haze=2145−2216*Fraction LMW −181*a molecular weight distribution of the LMW component (MWD LMW )−932*a molecular weight distribution of the HMW component(MWD HMW )+27*(Fraction LMW *MWD LMW )+1019*(Fraction LMW *MWD HMW )+73*(MWD LMW *MWD HMW ) wherein fraction refers to the weight fraction of the component in the polymer as a whole.

First claim

What is claimed is:

1. A bimodal polymer having a weight fraction of a lower molecular weight (LMW) component ranging from about 0.25 to about 0.45, a weight fraction of a higher molecular weight (HMW) component ranging from about 0.55 to about 0.75 and a density of from about 0.931 g/cc to about 0.955 g/cc which when tested in accordance with ASTM D1003 using a 1 mil test specimen displays a haze characterized by equation: % Haze=2145−2216*Fraction LMW −181* a molecular weight distribution of the LMW component (MWD LMW )−932* a molecular weight distribution of the HMW component(MWD HMW )+27*(Fraction LMW * MWD LMW )+1019*(Fraction LMW *MWD HMW )+73*(MWD LMW *MWD HMW ) wherein fraction refers to the weight fraction of the component in the polymer as a whole, wherein the bimodal polymer is produced by:
contacting a polymerization catalyst and monomer in the presence of hydrogen in one or more polymerization reactors to yield the bimodal polymer.

2. The bimodal polymer of claim 1 , wherein the one or more polymerization reactors is selected from batch, slurry, gas-phase, solution, high pressure, tubular, autoclave, or combinations thereof.

3. The bimodal polymer of claim 1 , wherein the one or more polymerization reactors comprises multiple loop reactors, multiple gas phase reactors, a combination of one or more loop reactors and one or more gas phase reactors, multiple high pressure reactors, or a high pressure reactor in combination with a loop reactor and/or a gas phase reactor.

4. The bimodal polymer of claim 1 , wherein the polymerization catalyst comprises a dual metallocene catalyst system.

5. The bimodal polymer of claim 4 , wherein the dual metallocene catalyst system comprises a tightly bridged metallocene compound having a substituent that includes a terminal olefin and an unbridged metallocene compound.

6. The bimodal polymer of claim 4 , wherein the polymerization catalyst further comprises an activator.

7. The bimodal polymer of claim 6 , wherein the activator comprises an organoaluminum compound.

8. The bimodal polymer of claim 4 , wherein the one or more polymerization reactors comprises multiple loop reactors, multiple gas phase reactors, a combination of one or more loop reactors and one or more gas phase reactors, multiple high pressure reactors, or a high pressure reactor in combination with a loop reactor and/or a gas phase reactor.

9. The bimodal polymer of claim 1 , wherein the polymerization catalyst is a polymerization catalyst system comprising:
a first catalyst composition which contacts the monomer in the presence of hydrogen in a first polymerization reactor of the one or more polymerization reactors under conditions sufficient to yield a first polymer product; and
a second catalyst composition which contacts the monomer in the presence of hydrogen in a second polymerization reactor of the one or more polymerization reactors under conditions sufficient to yield a second polymer product;
wherein the first polymer product, the second polymer product, or both the first polymer product and the second polymer product is the bimodal polymer.

10. The bimodal polymer of claim 9 , wherein the first catalyst composition comprises a tightly bridged metallocene compound having a substituent that includes a terminal olefin, wherein the second catalyst composition comprises an unbridged metallocene compound.

11. The bimodal polymer of claim 1 , wherein the monomer is ethylene, and wherein the bimodal polymer is a polyethylene polymer.

12. A film formed from a bimodal polymer having a weight fraction of a lower molecular weight (LMW component ranging from about 0.25 to about 0.45, a weight fraction of a higher molecular weight (HMW) component ranging from about 0.55 to about 0.75 and a density of from about 0.931 g/cc to about 0.955 g/cc which when tested in accordance with ASTM D1003 using a 1 mil test specimen displays a haze characterized by equation: %Haze=2145−2216*Fraction LMW −181* a molecular weight distribution of the LMW component (MWD LMW )−932*a molecular weight distribution of the HMW component(MWD HMW )+27*(Fraction LMW *MWD LMW )+1019*(Fraction LMW *MWD HMW )+73*(MWD LMW *MWD HMW ) wherein fraction refers to the weight fraction of the component in the polymer as a whole.

13. The film of claim 12 , comprising a polyethylene bimodal polymer.

14. An article formed from a bimodal polymer having a weight fraction of a lower molecular weight (I,MW) component ranging from about 0.25 to about 0.45, a weight fraction of a higher molecular weight (HMW) component ranging from about 0.55 to about 0.75 and a density of from about 0.931 g/cc to about 0.955 g/cc which when tested in accordance with ASTM D1003 using a 1 mil test specimen displays a haze characterized by equation: %Haze=2145−2216*Fraction LMW −181*a molecular weight distribution of the LMW component (MWD LMW )−932*a molecular weight distribution of the HMW component(MWD HMW )+27*(Fraction LMW *MWD LMW )+1019*(Fraction LMW *MWD HMW )+73*(MWD LMW *MWD HMW ) wherein fraction refers to the weight fraction of the component in the polymer as a whole.

15. The article of claim 14 , selected from a pipe, a bottle, a toy, a container, a utensil, a film product, a drum, a tank, a membrane, and a liner.

16. The article of claim 14 , wherein the bimodal polymer is a polyethylene polymer.

17. A process for producing a bimodal polymer comprising:
contacting a polymerization catalyst and monomer in the presence of hydrogen in one or more polymerization reactors to yield the bimodal polymer,
wherein the bimodal polymer has a weight fraction of a lower molecular weight (LMW) component ranging from about 0.25 to about 0.45 a weight fraction of a higher molecular weight (HMW) component ranging from about 0.55 to about 0.75 and a density of from about 0.931 g/cc to about 0.955 g/cc which when tested in accordance with ASTM D1003 using a 1 mil test specimen displays a haze characterized by equation: % Haze =2145−2216*Fraction LMW −181*a molecular weight distribution of the LMW component (MWD LMW )−932*a molecular weight distribution of the HMW component(MWD HMW )+27*(Fraction LMW *MWD LMW )+1019*(Fraction LMW *MWD HMW )+73*(MWD LMW *MWD HMW ) wherein fraction refers to the weight fraction of the component in the polymer as a whole.

Assignees

• Chevron Phillips Chemical Co

Inventors

• St Jean Guylaine
• Lanier Elizabeth M
• Lanier J Todd
• Yang Qing
• Gill Brooke A

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

• C08L2203/16

  used for films · CPC title

• Y10T428/1397

  Single layer [continuous layer] · CPC title

• C08F4/65927

  two cyclopentadienyl rings being mutually bridged · CPC title

• C08L2314/06

  Metallocene or single site catalysts · CPC title