# US 2013/0158227 A1 · Process for synthesizing a new catalyst complex for the production of polyethylene terephthlate

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- Number: US 2013/0158227 A1
- Document ID: US20130158227A1
- Status: Published application
- Kind: A1
- Application number: 13/716,555
- Filed: 2012-12-17
- Published: 2013-06-20
- Earliest claimed: 2011-12-16
- Assignees: Saudi Basic Industries Corporation
- Inventors: Bander Al-Farhood
- Web page: https://patentgrep.com/patent/US20130158227A1

## CPC

- C08G 63/84: Boron, aluminium, gallium, indium, thallium, rare-earth metals, or compounds thereof {(C08G63/823 takes precedence)}
- B01J 31/2226: {Anionic ligands, i.e. the overall ligand carries at least one formal negative charge}
- C08G 63/183: Terephthalic acids
- C08G 63/83: Alkali metals, alkaline earth metals, beryllium, magnesium, copper, silver, gold, zinc, cadmium, mercury, manganese, or compounds thereof {(C08G63/823 takes precedence)}
- B01J 2531/26: Zinc
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

This invention relates to a process of preparing a catalyst for the production of polyethylene terephthalate and for the production of high molecular weight PET comprising: a) reacting boric acid and a zinc salt in a solvent comprising at least one glycol selected from ethylene glycol, propylene glycol, and butylene glycol thereby forming a precipitate; and b) isolating the precipitate. In addition, the use of the catalyst for the production of polyethylene terephthalate and for the production of high molecular weight PET is disclosed.

## Claims

### Claim 1

A process of preparing a catalyst for the production of polyethylene terephthalate comprising:
reacting boric acid and a zinc salt in a solvent comprising at least one glycol selected from ethylene glycol, propylene glycol, and butylene glycol, thereby forming a precipitate; and
isolating the precipitate.

### Claim 2 (depends on 1)

The process according to claim 1, wherein the boric acid is solved in the solvent to form a solution, and the zinc salt is combined with the solution either in solid form or in the form of a zinc solution in the solvent.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the reaction between the boric acid and the zinc salt is performed under inert atmosphere.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the reaction between the boric acid and the zinc salt is performed at a temperature of 100° C. to the boiling temperature of the solution.

### Claim 5 (depends on 1)

The process according to claim 1, wherein the molar ratio between boric acid and zinc is between 0.3 and 0.7.

### Claim 6

A process of preparing a catalyst for the production of polyethylene terephthalate comprising:
forming a boric acid solution of boric acid solved in a solvent comprising at least one glycol selected from ethylene glycol, propylene glycol, and butylene glycol;
combining the boric acid solution and the zinc salt to form a reaction solution;
reacting the reaction solution under an inert atmosphere and at a temperature of 100° C. to the boiling temperature of the reaction solution to form a precipitate; and
isolating the precipitate.

### Claim 7 (depends on 6)

The process according to claim 6, wherein the zinc salt is solved in the solvent to form a zinc solution before combining the zinc salt with the boric acid solution.

### Claim 8 (depends on 6)

The process according to claim 6, wherein the molar ratio between boric acid and zinc is between 0.3 and 0.7.

### Claim 9 (depends on 6)

The process according to claim 6, wherein the precipitate has the chemical composition C4H8O9B2Zn4.

### Claim 10

A catalyst for the production of polyethylene terephthalate obtainable by a process comprising
reacting boric acid and a zinc salt in a solvent comprising at least one glycol selected from ethylene glycol, propylene glycol, and butylene glycol, thereby forming a precipitate; and
isolating the precipitate.

### Claim 11 (depends on 10)

The catalyst according to claim 10, having the chemical composition C4H8O9B2Zn4.

### Claim 12

A catalyst for the production of polyethylene terephthalate having the chemical composition C4H8O9B2Zn4.

### Claim 13

A method of manufacturing polyethylene terephthalate comprising:
polymerization of terephthalic acid, ethylene glycol and optionally isophthalic acid in the molten state in the presence of a catalyst, wherein the catalyst was obtained by a process comprising
reacting boric acid and a zinc salt in a solvent comprising at least one glycol selected from ethylene glycol, propylene glycol, and butylene glycol, thereby forming a precipitate; and
isolating the precipitate; and
after reaching an intrinsic viscosity of at least 0.66 dL/g, solidifying the molten polymer and continuing the polymerization in the solid state until an intrinsic viscosity of at least 1.00 is reached.

### Claim 14 (depends on 13)

The method according to claim 13, wherein the catalyst has the chemical composition C4H8O9B2Zn4.

### Claim 15 (depends on 13)

Polyethylene terephthalate produced according to claim 13.