Method to improve the feeding of a carboxylic acid comonomer into a high pressure reactor

Patent metadata

Field	Value
Publication number	US-9416209-B2
Application number	US-201314438930-A
Country	US
Kind code	B2
Filing date	Dec 27, 2013
Priority date	Dec 28, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

The invention provides a method of injecting a compressed “comonomer/compound mixture,” comprising a “comonomer comprising a carboxylic acid,” and at least one compound, into at least one reactor; said method comprising, adding the at least one compound to the comonomer to form the “comonomer/compound mixture,” prior to compressing and injecting the mixture into the reactor; and wherein the crystallization temperature, at pressure P, of the “comonomer/compound mixture” is at least 5° C. lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound; and wherein the pressure P is greater than 500 bar; and wherein the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1; and wherein the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture; and wherein the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer. The invention also provides a method of forming an ethylene-based polymer, as described herein.

First claim

The invention claimed is:

1. A method of injecting a compressed “comonomer/compound mixture,” comprising a “comonomer comprising a carboxylic acid,” and at least one compound, into at least one reactor;
said method comprising, adding the at least one compound to the comonomer to form the “comonomer/compound mixture,” prior to compressing and injecting the mixture into the reactor; and
wherein the crystallization temperature, at pressure P, of the “comonomer/compound mixture” is at least 5° C. lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound; and
wherein the pressure P is greater than 500 bar; and
wherein the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1; and
wherein the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture; and
wherein the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.

2. The method of claim 1 , wherein the at least one compound has a boiling temperature, at atmospheric pressure, greater than, or equal to, 70° C.

3. The method of claim 1 , wherein the comonomer/compound mixture comprises less than 2 weight percent ethylene, based on the weight of the mixture.

4. The method of claim 1 , wherein the at least one compound is a chain transfer agent.

5. The method of claim 1 , wherein the at least one compound has a chain transfer activity coefficient (Cs at 130° C. and 1360 atm) from 0.0025 to 0.5.

6. The method of claim 1 , wherein at least two compounds are added to the comonomer, and wherein one compound has a higher Cs value than the other compound.

7. The method of claim 6 , wherein the ratio of the “Cs value of the compound with the higher Cs value” to the “Cs value of the other compound” is greater than, or equal to, 2.

8. The method of claim 1 , wherein the at least one compound comprises at least one chemical group selected from the following: an alcohol, a ketone, an aldehyde, an ester, a carboxylic acid, a vinyl group, or a combination thereof.

9. A method of forming an ethylene-based polymer, said method comprising polymerizing a comonomer, comprising a carboxylic acid, in the presence of ethylene and at least one free radical initiator; and
wherein at least one compound is added to the comonomer to form a “comonomer/compound mixture;” and then the mixture is compressed, and injected into at least one reactor; and
wherein the crystallization temperature, at pressure P, of the “comonomer/compound mixture” is at least 5° C. lower than the crystallization temperature, at pressure P, of the comonomer, without the presence of the at least one compound; and
wherein the pressure P is greater than 500 bar; and
wherein the molar ratio of the at least one compound to the comonomer in the mixture is from 1/10 to 1/1; and
wherein the comonomer/compound mixture comprises greater than, or equal to, 30 weight percent of the comonomer, based on the weight of the comonomer/compound mixture; and
wherein the melting temperature, at atmospheric pressure, of the at least one compound is less than the melting temperature, at atmospheric pressure, of the comonomer.

10. The method of claim 9 , wherein at least some of unreacted ethylene and/or some of unreacted comonomer is/are recycled to a reactor inlet.

11. The method of claim 9 , wherein at least some of the compound is condensed and recycled to one or more comonomer feed stream(s).

12. The method of claim 9 , wherein the level of the at least one compound in a reactor feed is maintained from 1 to 10 molar percent, based on the total moles of components in the feed.

13. The method of claim 9 , wherein the at least one compound is a chain transfer agent.

14. The method of claim 9 , wherein the at least one compound comprises at least one chemical group selected from the following: an alcohol, a ketone, an aldehyde, an ester, a carboxylic acid, a vinyl group, or a combination thereof.

15. The method of claim 1 , wherein the mixture comprises less than 2 weight percent ethylene, based on the weight of the mixture.

16. The method of claim 9 , wherein the mixture comprises less than 2 weight percent ethylene, based on the weight of the mixture.

Assignees

• Dow Global Technologies Llc

Inventors

• Berbee Otto J
• Bradley Jeffery S
• Hinrichs Stefan

Classifications

• C08F210/02

  Ethene · CPC title

• C08F220/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• C08F218/08

  Vinyl acetate · CPC title

• C08F220/06 Primary

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08F2/00

  Processes of polymerisation · CPC title