# US 2014/0155573 A1 · Process for purifying poly (alkylene carbonate)

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- Number: US 2014/0155573 A1
- Document ID: US20140155573A1
- Status: Published application
- Kind: A1
- Application number: 14/232,250
- Filed: 2012-07-11
- Published: 2014-06-05
- Earliest claimed: 2011-07-12
- Assignees: Norner IP AS
- Inventors: Carlos Barreto Soler; Siw Bodil Fredriksen; Espen Ommundsen
- Web page: https://patentgrep.com/patent/US20140155573A1

## CPC

- C08G 64/406: {Purifying; Drying}
- C08G 64/0208: {saturated}
- C08G 64/34: and cyclic ethers
- C08J 5/18: Manufacture of films or sheets
- C08J 2369/00: Characterised by the use of polycarbonates; Derivatives of polycarbonates
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

A process for purifying a poly(alkylene carbonate), said process comprising the steps of adding said poly(alkylene carbonate) to an aqueous solution, optionally in the presence of an acid compound, in the absence of any organic solvent. subsequently heating said blend to a temperature of up to 200° C.; and removing the aqueous phase and drying the residue.

## Claims

### Claim 1

A process for purifying a poly(alkylene carbonate), said process comprising the steps of:
(i) adding said poly(alkylene carbonate) to water in the absence of any organic solvent to form a solid:liquid blend, said poly(alkylene carbonate) having a particle size less than 20 mm;
(ii) heating said blend to a temperature of up to 200° C.; and
(iii) removing the aqueous phase and optionally drying the residue.

### Claim 2

A process for purifying a poly(alkylene carbonate), said process comprising the steps of:
(i) adding said poly(alkylene carbonate) to an aqueous acid solution in the absence of any organic solvent;
(ii) heating said blend to a temperature of up to 200° C.; and
(iii) removing the aqueous phase and optionally drying the residue.

### Claim 3

A process comprising:
(a) reacting carbon dioxide with a cyclic ether in the presence of a catalyst and an organic solvent so as to form a poly(alkylene carbonate);
(b) removing said organic solvent to leave a crude poly(alkylene carbonate);
(c) optionally converting said poly(alkylene carbonate) into particles having a particle size less than 20 mm;
(d) adding said crude poly(alkylene carbonate) to water, optionally in the presence of an acid, in the absence of any organic solvent to form a solid:liquid blend, and
(e) removing the aqueous phase and optionally drying the residue.

### Claim 4 (depends on 1)

The process of claim 1 wherein the poly(alkylene carbonate) is a copolymer of carbon dioxide and one or more of propylene oxide, ethylene oxide or cyclohexene oxide.

### Claim 5 (depends on 1)

The process of claim 1, wherein the poly(alkylene carbonate) is poly (ethylene carbonate), poly(propylene carbonate) or poly(cyclohexene carbonate).

### Claim 6 (depends on 2)

The process of claim 2, wherein said aqueous acid is an organic carboxylic acid, organic anhydride or organic carboxylic acid salt.

### Claim 7 (depends on 2)

The process of claim 2, wherein said aqueous acid is polyfunctional.

### Claim 8 (depends on 2)

The process of claim 2, wherein said aqueous acid is maleic acid, formic acid, acetic acid, lactic acid, maleic anhydride, citric acid ,glutaric acid, acrylic acid, methacrylic acid, pyromellitic dianhydride, trimellitic anhydride , poly acrylic acid, poly methacrylic acid , poly (acrylic acid-co-maleic acid), poly (acrylic acid-co-ethylene), poly (acrylic acid-co styrene), poly (methacrylic acid-co-maleic acid), poly (methacrylic acid-co ethylene), or poly (methacrylic acid-co styrene).

### Claim 9 (depends on 2)

The process of claim 2, wherein said poly(alkylene carbonate) before being added in step (i) has a metal ion content of 0.5 to 100,000 wtppm.

### Claim 10 (depends on 2)

A poly(alkylene carbonate) obtained by the process of claim 2 and comprising at least 0.001 wt % of metal ions.

### Claim 11 (depends on 2)

A poly(alkylene carbonate) obtained by the process of claim 2 having an onset of thermal decomposition, as measured by thermogravametric analysis in N2 at 2° C./min or faster, which is higher than the same poly(alkylene carbonate) obtained by a process of claim 2 in the absence of said acid.

### Claim 12

(canceled)

### Claim 13 (depends on 10)

An article comprising a poly (alkylene carbonate) as claimed in claim 10 wherein the article is a molded article, film, or circuit board.

### Claim 14 (depends on 1)

The process of claim 1, wherein said poly(alkylene carbonate) has a particle size less than 5 mm.

### Claim 15 (depends on 1)

The process of claim 1, wherein said poly(alkylene carbonate) before being added in step (i) has a metal ion content of 0.5 to 100,000 wtppm.

### Claim 16 (depends on 1)

A poly(alkylene carbonate) obtained by the process of claim 1 and comprising at least 0.001 wt % of metal ions.

### Claim 17 (depends on 2)

The process of claim 2, wherein the poly(alkylene carbonate) is a copolymer of carbon dioxide and one or more of propylene oxide, ethylene oxide or cyclohexene oxide.

### Claim 18 (depends on 2)

The process of claim 2, wherein the poly(alkylene carbonate) is poly (ethylene carbonate), poly(propylene carbonate) or poly(cyclohexene carbonate).

### Claim 19 (depends on 3)

The process of claim 3, wherein the poly(alkylene carbonate) is a copolymer of carbon dioxide and one or more of propylene oxide, ethylene oxide or cyclohexene oxide.

### Claim 20 (depends on 3)

The process of claim 3, wherein the poly(alkylene carbonate) is poly (ethylene carbonate), poly(propylene carbonate) or poly(cyclohexene carbonate).

### Claim 21 (depends on 3)

The process of claim 3, wherein the catalyst is a zinc catalyst.