Claims
- 1. A method for solid state polymerizing polyester, said method comprising:
- providing a mixture comprising polyester and carbon dioxide;
- treating said polyester with carbon dioxide to increase the crystallinity of the carbon dioxide; and
- treating said polyester with an inert gas to solid state polymerize said polyester.
- 2. The method according to claim 1, wherein said polyester is present in the form of pellets.
- 3. The method according to claim 1, further comprising the step of producing said solid state polymerized polyester into a molded article.
- 4. The method according to claim 1, wherein said polyester is polyethylene terephthalate.
- 5. The method according to claim 1, wherein said carbon dioxide is supercritical carbon dioxide.
- 6. The method according to claim 1, wherein said inert solvent is selected from
- the group consisting of nitrogen, carbon dioxide, and mixtures thereof.
CROSS REFERENCE TO RELATED APPLICATIONS
The instant application is a continuation application of Ser. No. 08/903,269 filed Jul. 25, 1997, which is a file wrapper continuation of Ser. No. 08/471,500 filed Jun. 6, 1995, now abandoned. The disclosures of these applications are incorporated herein by reference in their entirety.
US Referenced Citations (26)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0 300 981 A1 |
Jan 1989 |
EPX |
0356815 |
Mar 1990 |
EPX |
Continuations (2)
|
Number |
Date |
Country |
Parent |
903269 |
Jul 1997 |
|
Parent |
471500 |
Jun 1995 |
|