# US 11,440,980 B2 · Methods for forming ultra high molecular weight polyethylenes and methods for reducing contaminant content in such

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- Number: US 11,440,980 B2
- Document ID: US11440980B2
- Status: Granted
- Kind: B2
- Application number: 16/935,842
- Filed: 2020-07-22
- Published: 2022-01-27
- Granted: 2022-09-13
- Earliest claimed: 2020-07-22
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Motaz Khawaji; Faisal Melebari; Hussain Al Yami; Wei Xu
- Web page: https://patentgrep.com/patent/US11440980B2

## CPC

- C08F 6/008: {Treatment of solid polymer wetted by water or organic solvents, e.g. coagulum, filter cakes}
- C08F 6/02: Neutralisation of the polymerisation mass, e.g. killing the catalyst (short-stopping C08F2/42 ){also removal of catalyst residues}
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

According to one or more embodiments disclosed herein, the amount of one or more contaminants in an initial ultra high molecular weight polyethylene composition may be reduced by a method including contacting the initial ultra high molecular weight polyethylene composition with an acid to form a processed ultra high molecular weight polyethylene composition. The initial ultra high molecular weight polyethylene composition may include at least 0.02 wt. % of one or more contaminants. The contacting of the acid with the initial ultra high molecular weight polyethylene composition may be for a time, at a pressure, and at a temperature sufficient to reduce the amount of the one or more contaminants in the initial ultra high molecular weight polyethylene.

## Claims

### Claim 1

A method for reducing the amount of one or more contaminants in an initial ultra high molecular weight polyethylene composition, the method comprising:
contacting the initial ultra high molecular weight polyethylene composition with an acid to form a processed ultra high molecular weight polyethylene composition, wherein:
the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % of one or more contaminants;
the contacting of the acid with the initial ultra high molecular weight polyethylene composition is for a time, at a pressure, and at a temperature sufficient to reduce the amount of the one or more contaminants in the initial ultra high molecular weight polyethylene such that the total amount of contaminants in the processed ultra high molecular weight polyethylene composition is less than or equal to 95% by weight of the total amount of contaminants in the initial ultra high molecular weight polyethylene composition; and
the one or more contaminants are selected from the group consisting of titanium, aluminum, zirconium, chromium, nickel, hafnium, scandium, magnesium, boron, phosphorus, fluorine, chlorine, nitrogen, silicon, and combinations of these.

### Claim 2 (depends on 1)

The method of claim 1, wherein the acid comprises one or more inorganic acids.

### Claim 3 (depends on 2)

The method of claim 2, wherein the acid comprises hydrochloric acid, nitric acid, or combinations of these.

### Claim 4 (depends on 1)

The method of claim 1, wherein the contacting of the acid with the initial ultra high molecular weight polyethylene composition occurs at a temperature from 25° C. to 200° C.

### Claim 5 (depends on 1)

The method of claim 1, wherein the contacting of the acid with the initial ultra high molecular weight polyethylene composition occurs at a pressure from ambient pressure to 60 bar.

### Claim 6 (depends on 1)

The method of claim 1, wherein the one or more contaminants are selected from the group consisting of titanium, aluminum, and combinations of these.

### Claim 7 (depends on 1)

The method of claim 1, wherein the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % aluminum.

### Claim 8 (depends on 1)

The method of claim 1, wherein the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % titanium.

### Claim 9 (depends on 1)

The method of claim 1, wherein the processed ultra high molecular weight polyethylene composition comprises less than or equal to 5 wt. % of the one or more contaminants.

### Claim 10 (depends on 1)

The method of claim 1, wherein the processed ultra high molecular weight polyethylene composition comprises less than or equal to 5 wt. % aluminum.

### Claim 11 (depends on 1)

The method of claim 1, wherein the processed ultra high molecular weight polyethylene composition comprises less than or equal to 5 wt. % titanium.

### Claim 12 (depends on 1)

The method of claim 1, further comprising removing at least a portion of the acid from the processed ultra high molecular weight polyethylene composition.

### Claim 13 (depends on 12)

The method of claim 12, wherein the removing of the at least a portion of the acid from the processed ultra high molecular weight polyethylene composition comprises washing the processed ultra high molecular weight polyethylene composition with water.

### Claim 14 (depends on 13)

The method of claim 13, wherein the removing of the at least a portion of the acid from the processed ultra high molecular weight polyethylene composition further comprises drying the processed ultra high molecular weight polyethylene composition.

### Claim 15

A method for forming an ultra high molecular weight polyethylene, the method comprising:
oligomerizing ethylene in the presence of at least an oligomerization catalyst and an anti-fouling agent, wherein one or both of the oligomerization catalyst and an anti-fouling agent comprise one or more contaminants selected from the group consisting of titanium, aluminum, zirconium, chromium, nickel, hafnium, scandium, magnesium, boron, phosphorus, fluorine, chlorine, nitrogen, silicon, and combinations of these;
forming an initial ultra high molecular weight polyethylene composition as a byproduct of the oligomerizing of the ethylene, wherein the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % of the one or more contaminants of the oligomerization catalyst, the anti-fouling agent, or both, and wherein the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % of one or more contaminants; and
contacting the initial ultra high molecular weight polyethylene composition with an acid to form a processed ultra high molecular weight polyethylene composition, wherein the contacting of the acid with the initial ultra high molecular weight polyethylene composition is for a time, at a pressure, and at a temperature sufficient to reduce the amount of the one or more contaminants in the initial ultra high molecular weight polyethylene composition by at least 5 wt. %.

### Claim 16 (depends on 15)

The method of claim 15, wherein the acid comprises one or more inorganic acids.

### Claim 17 (depends on 15)

The method of claim 15, wherein the contacting of the acid with the initial ultra high molecular weight polyethylene composition occurs at a temperature from 25° C. to 200° C.

### Claim 18 (depends on 15)

The method of claim 15, wherein the contacting of the acid with the initial ultra high molecular weight polyethylene composition occurs at a pressure from ambient pressure to 60 bar.

### Claim 19 (depends on 15)

The method of claim 15, wherein the processed ultra high molecular weight polyethylene composition comprises less than or equal to 5 wt. % of the one or more contaminants.

### Claim 20

A method for reducing the amount of one or more contaminants in an initial ultra high molecular weight polyethylene composition, the method comprising:
contacting the initial ultra high molecular weight polyethylene composition with an acid to form a processed ultra high molecular weight polyethylene composition, wherein:
the contacting of the acid with the initial ultra high molecular weight polyethylene composition is for a time, at a pressure, and at a temperature sufficient to reduce the amount of the one or more contaminants in the initial ultra high molecular weight polyethylene such that the total amount of contaminants in the processed ultra high molecular weight polyethylene composition is less than or equal to 95% by weight of the total amount of contaminants in the initial ultra high molecular weight polyethylene composition;
the initial ultra high molecular weight polyethylene composition comprises at least 0.02 wt. % of one or more contaminants;
the acid comprises hydrochloric acid, nitric acid, or combinations of these;
the contacting of the acid with the initial ultra high molecular weight polyethylene composition occurs at a temperature from 25° C. to 200° C. and pressure from ambient pressure to 60 bar;
the one or more contaminants are selected from the group consisting of titanium, aluminum, and combinations of these; and
the processed ultra high molecular weight polyethylene composition comprises less than or equal to 5 wt. % of the one or more contaminants;
washing the processed ultra high molecular weight polyethylene composition with water; and
drying the processed ultra high molecular weight polyethylene composition.
