Process for purifying poly (alkylene carbonate)

• US 9,340,646 B2
• Filed: 07/11/2012
• Issued: 05/17/2016
• Est. Priority Date: 07/12/2011
• Status: Active Grant

• Current Assignee: Norner Ip AS
• Original Assignee: Norner Ip AS
• Inventors: Soler, Carlos Barreto, Fredriksen, Siw Bodil, Ommundsen, Espen
• Primary Examiner(s): Truong, Duc
• Application Number:
  US14/232,250
• Publication Number:
  US 20140155573A1
• Time in Patent Office: 1,406 Days
• Field of Search: 528/405, 528/412, 528/413, 528/414, 528/503
• US Class Current: 1/1
• CPC Class Codes: C08G 64/0208 saturated
• CPC Class Codes: C08G 64/34 and cyclic ethers
• CPC Class Codes: C08G 64/406 Purifying; Drying
• CPC Class Codes: C08J 2369/00 Characterised by the use of polycarbonates; Derivatives of polycarbonates
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets

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

1. A process for purifying a poly(alkylene carbonate), comprising the steps of:

(i) adding the poly(alkylene carbonate) to water or an aqueous acid solution in the absence of any organic solvent to form a solid;

liquid blend, the poly(alkylene carbonate) having a particle size less than 5 mm,

(ii) heating the solid;

liquid blend to a temperature of up to 200°

C.; and

(iii) removing the liquid from the solid;

liquid blend, thereby leaving a solid residue, and optionally drying the residue.

2. The process of claim 1, wherein the poly(alkylene carbonate) is added to the aqueous acid solution.

3. The process of claim 1, wherein the poly(alkylene carbonate) is prepared by:

(a) reacting carbon dioxide with a cyclic ether in the presence of a catalyst and an organic solvent so as to form a crude poly(alkylene carbonate) in the organic solvent;

(b) removing the organic solvent from the crude poly(alkylene carbonate); and

(c) optionally converting the crude poly(alkylene carbonate) into particles having a particle size less than 5 mm.

4. 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.

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

6. The process of claim 2, wherein the aqueous acid comprises an organic carboxylic acid, organic anhydride or organic carboxylic acid salt.

7. The process of claim 2, wherein the aqueous acid comprises a polyfunctional acid.

8. The process of claim 2, wherein the aqueous acid comprises 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).

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

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

11. 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.

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

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

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

15. 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.

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

17. 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.

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

19. The process of claim 3, wherein the catalyst comprises manganese, magnesium, cobalt, or zinc.