# US 2021/0079136 A1 · Method for Preparing Ethylene Vinylacetate Copolymer

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- Number: US 2021/0079136 A1
- Document ID: US20210079136A1
- Status: Published application
- Kind: A1
- Application number: 16/757,533
- Filed: 2018-10-30
- Published: 2021-03-18
- Earliest claimed: 2017-11-03
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Dae Young Shin; Eun Jung Joo; Jin Ho Jung; Choong Hoon Lee; Kyung Soo Park; Yutaek Sung
- Web page: https://patentgrep.com/patent/US20210079136A1

## CPC

- C08F 2/02: Polymerisation in bulk
- C08F 210/02: Ethene
- B01J 3/04: Pressure vessels, e.g. autoclaves
- C08F 2/01: characterised by special features of the polymerisation apparatus used
- C08F 18/08: Vinyl acetate
- C08K 5/14: Peroxides
- C08L 23/0853: Ethylene vinyl acetate copolymers
- B01J 2203/065: Composition of the material produced
- B01J 2219/00051: Controlling the temperature
- B01J 2219/00162: controlling the pressure
- C08F 2400/02: Control or adjustment of polymerization parameters
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The present invention relates to a method for preparing ethylene vinylacetate copolymer that can improve the mechanical strength of copolymer by controlling the polymerization conditions using an autoclave reactor.

## Claims

### Claim 1

A method for preparing ethylene vinylacetate copolymer comprising:
polymerizing ethylene monomers and vinylacetate monomers in an autoclave reactor, in the presence of an initiator,
wherein a temperature of an upper stage of the autoclave reactor during the polymerizing step is 130 to 160° C.,
a temperature of a lower stage of the autoclave reactor during the polymerizing is 170 to 230° C., and
a pressure of the autoclave reactor is 1800 to 2100 bar.

### Claim 2 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein a number average molecular weight(Mn) of the ethylene vinylacetate copolymer is 14,000 to 19,500 g/mol.

### Claim 3 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein the ethylene vinylacetate copolymer has a content of long chain branches of 0.1 to 2 per a carbon number of 1,000.

### Claim 4 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein the initiator includes a low temperature initiator and a high temperature initiator.

### Claim 5 (depends on 4)

The method for preparing ethylene vinylacetate copolymer according to claim 4, wherein the low temperature initiator and the high temperature initiator are included at a weight ratio of 5:95 to 90:10.

### Claim 6 (depends on 4)

The method for preparing ethylene vinylacetate copolymer according to claim 4, wherein the low temperature initiator includes one or more of DIPND(1,4-di(2-neodecanoylperoxyisopropyl)benzene), CUPND(Cumylperoxy neodecanoate), SBPC(Di(sec-butyl) peroxydicarbonate), NBPC(Di(n-butyl)peroxydicarbonate), EHP(Di(2-ethylhexyl) peroxydicarbonate), TAPND(Tert-amylperoxyneodecanoate) or TBPND(Tert-butyl peroxyneodecanoate).

### Claim 7 (depends on 4)

The method for preparing ethylene vinylacetate copolymer according to claim 4, wherein the high temperature initiator includes one or more of TAPPI(Tert-amylperoxy pivalate), TBPPI(Tert-butylperoxy pivalate), INP(Di(3,5,5-trimethylhexanoyl) peroxide), TAPEH(Tert-amylperoxy 2-ethylhexanoate), TBPEH(Tert-butylperoxy 2-ethylhexanoate), TBPIB(Tert-butylperoxy-isobutyrate), TBPIN(Tert-butylperoxy-3,5,5-trimethylhexanoate) or TBPA(Tert-butylperoxyacetate).

### Claim 8 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein the vinylacetate monomers are included in a content of 15 to 40 parts by weight, based on 100 parts by weight of a sum of ethylene monomers and vinylacetate monomers.

### Claim 9 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein the ethylene vinylacetate copolymer has a polydispersity index (PDI, Mw/Mn) of 3 to 4.5.

### Claim 10 (depends on 1)

The method for preparing ethylene vinylacetate copolymer according to claim 1, wherein the ethylene vinylacetate copolymer has a weight average molecular weight (Mw) of 40,000 to 64,000 g/mol.