# US 11,441,012 B2 · Use of at least one phenolic compound to stabilise ethylene copolymerisation reactions

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- Number: US 11,441,012 B2
- Document ID: US11441012B2
- Status: Granted
- Kind: B2
- Application number: 16/468,033
- Filed: 2017-12-22
- Published: 2020-01-09
- Granted: 2022-09-13
- Earliest claimed: 2016-12-23
- Assignees: SK Global Chemical Co., Ltd.
- Applicants: SK Global Chemical Co., Ltd.
- Inventors: Christian Laurichesse; Thibaut Severac; Angélique Lelievre; Claire Isabelle Michalowicz; Louis Defoor; Yves Cabon
- Web page: https://patentgrep.com/patent/US11441012B2

## CPC

- C08K 5/1545: Six-membered rings
- C07D 311/72: 3,4-Dihydro derivatives having in position 2 at least one methyl radical and in position 6 one oxygen atom, e.g. tocopherols
- C08F 210/02: Ethene
- C08K 5/13: Phenols; Phenolates
- C08L 23/06: Polyethylene
- C08L 23/08: Copolymers of ethene (C08L23/16 takes precedence)
- C08F 2410/01: Additive used together with the catalyst, excluding compounds containing Al or B
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

A method of stabilizing radical ethylene copolymerization reactions for approximately 5 to 10 minutes, the method including using a phenolic compound with other comonomers and performing the radical ethylene copolymerization reactions at high pressure. Also, a method of preparing an ethylene copolymer at high pressure in the presence of one or more phenolic compounds, as defined below, and one or more initiators.

## Claims

### Claim 1

A method of stabilizing radical ethylene copolymerization reactions for approximately 5 to 10 minutes, the method comprising using a phenolic compound with other comonomers, wherein the phenolic compound possesses a structure according to Formula (I):
wherein:
R1 represents:
a hydrogen atom;
a linear C1-C8 alkyl radical;
a linear C1-C8 hydroxyalkyl radical; or
a hydroxy group;
R2, R3, R4 and R5, identical or different, represent:
a hydrogen atom;
a C1-C8 alkyl radical, linear or branched, optionally substituted by one or more hydroxy radicals;
a C1-C8 alkoxy radical, linear or branched, optionally substituted by one or more hydroxy radicals; or
a hydroxy group, and
it being understood that R4 and R5 can together form a five- or six-member cycle comprising an oxygen atom; said cycle being substituted by a C1-C17 alkyl radical, linear or branched;
wherein the other comonomers comprise unsaturated carboxylic acid esters (or their salts), and optionally at least one other comonomer selected from the group consisting of carboxylic acid anhydrides, vinyl esters, alpha-olefins, unsaturated carboxylic acids, derivatives of (meth)acrylic acid, vinyl ethers, aromatic vinyl compounds, carbon monoxide, and mixtures thereof;
wherein the unsaturated carboxylic acid esters include a C1-C24 (meth)alkyl acrylate and a (meth)acrylate possessing an epoxy group;
wherein the method further comprises performing the radical ethylene copolymerization reactions at a high pressure in the presence of one or more initiators,
wherein the method further includes a step of introducing a reaction mixture comprising ethylene and the comonomers into a reactor with a residence time of 30 to approximately 50 seconds and does not include a step in which the comonomers are preheated prior to the introduction of said one or more initiators, and
wherein the method limits the decomposition of the ethylene during the radical ethylene copolymerization reactions at the high pressure.

### Claim 2 (depends on 1)

The method of claim 1, wherein the radical copolymerization reactions are performed in an autoclave reactor.

### Claim 3 (depends on 2)

The method of claim 2, further comprising injecting the one or more initiators into a reaction mixture at a temperature below 100° C.

### Claim 4 (depends on 1)

The method of claim 1, wherein the radical copolymerization reactions are performed at a pressure from 50 MPa to 300 MPa.

### Claim 5 (depends on 1)

A polymer composition obtained by radical ethylene copolymerization reactions according to claim 1.

### Claim 6 (depends on 1)

The method of claim 1, wherein in Formula (I) of the phenolic compound:
R1 represents:
a hydrogen atom; or
a linear C1-C4 radical alkyl;
R2, R3 and R4, identical or different, represent:
a hydrogen atom;
a C1-C5 radical alkyl, linear or branched; or
a hydroxy group;
R5 represents:
a hydrogen atom;
a C1-C5 radical alkyl, linear or branched;
a C1-C5 radical alkoxy, linear or branched; or
a hydroxy group; and
it being understood that R4 and R5 can together form a six-member cycle comprising an oxygen atom; said cycle being substituted by a branched C1-C17 alkyl radical.

### Claim 7 (depends on 1)

The method of claim 1, wherein in Formula (I) of the phenolic compound:
R1, R2 and R3, identical or different, represent:
a hydrogen atom; or
a methyl radical; and
R4 and R5 together form a six-member cycle comprising an oxygen atom; said cycle being substituted by a branched C1-C17 alkyl radical.

### Claim 8 (depends on 1)

The method of claim 1, wherein the phenolic compound is chosen from Formula (I′):
Formula (I′), wherein
R1, R2 and R3, identical or different, represent:
a hydrogen atom; or
a methyl radical.

### Claim 9 (depends on 1)

The method of claim 1, wherein in Formula (I) of the phenolic compound:
R1, R2, R3 and R5 represent a hydrogen atom; and
R4 represents a C1-C5 alkoxy radical.

### Claim 10 (depends on 1)

The method of claim 1, wherein in Formula (I) of the phenolic compound:
R1 and R3 represent a hydrogen atom;
R2 and R5 represent a branched C3-C8 alkyl radical; and
R4 represents a hydroxy group.

### Claim 11 (depends on 1)

The method of claim 1, wherein the phenolic compound of Formula (I) is selected from the group consisting of 2,5-di-tert-butyl hydroquinone, 2,5-di(tert-amyl)hydroquinone, vitamin E and monomethyl ether hydroquinone.

### Claim 12 (depends on 1)

The method of claim 1, wherein the phenolic compound of Formula (I) is vitamin E.

### Claim 13 (depends on 1)

The method of claim 1, wherein the initiator(s) is or are selected from the group consisting of organic peroxides, oxygen azobisisobutyronitrile (AIBN) and mixtures thereof.

### Claim 14 (depends on 13)

The method of claim 13, wherein the organic peroxides is or are selected from the group consisting of peroxy esters, dialkyl peroxides, hydroperoxides and peroxycetals.

### Claim 15 (depends on 1)

The method according to claim 1, wherein the C1-C24 (meth)alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl-2-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate; and the (meth)acrylate possessing an epoxy group is selected from the group consisting of glycidyl methacrylate and glycidyl acrylate.

### Claim 16 (depends on 15)

The method according to claim 15, wherein the C1-C24 (meth)alkyl acrylate is methyl acrylate, and the (meth)acrylate possessing an epoxy group is glycidyl methacrylate.