Patent EP0269583A2 successfully refreshed from Google Patents.
EP0269583A2
Expired / Lapsed
EP
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A method for producing high molecular weight polyester resin
Assignee: Cobarr SpA
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Filing: 1987-11-12
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Granted: —
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Expires: 2007-11-12
Abstract
Abstract A solid state method for the polycondensation of granulate polyester resins comprises a preliminary step of treatment on a fixed bed with carbon dioxide effective to prevent the granules from sticking together.
Inventors
- 👤 Hussain Ali-Kashif Al Ghatta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 22:49
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/80; B; B29; B29K; B29K2105/00; B29K2105/0002
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
55 words
A method of preparing high molecular weight polyester resin, wherein resin granules, in particular granules of polyethyleneterephtalate, are subjected to solid state polycondensation on a fixed bed, characterized in that it comprises the step of treating the granules, prior to polycondensation, with carbon dioxide at a higher temperature than the critical temperature of carbon dioxide.
Claim 2
Independent Claim
55 words
A method of preparing high molecular weight polyester resin, wherein resin granules, in particular granules of polyethyleneterephtalate, are subjected to solid state polycondensation on a fixed bed, characterized in that it comprises the step of treating the granules, prior to polycondensation, with carbon dioxide at a higher temperature than the critical temperature of carbon dioxide.
Claim 3
Dependent Claim
21 words
A method according to Claim 1, characterized in that said treatment is carried out with carbon dioxide in a supercritical condition.
Claim 4
Dependent Claim
21 words
A method according to either Claim 1 or 2, characterized in that said treatment is carried out on a fixed bed.
Claim 5
Dependent Claim
25 words
A method according to Claim 1, characterized in that the treatment with carbon dioxide is carried out at a pressure in excess of 25 bars.
Claim 6
Independent Claim
25 words
A method according to any of the preceding claims, characterized in that the carbon dioxide treatment temperature is within the range of 31°C to 240°C.
Claim 7
Independent Claim
27 words
A method according to any of Claims 1 to 4, characterized in that the time duration of the carbon dioxide treatment varies between 0.5 and 5 hours.
Claim 8
Independent Claim
22 words
A method according to any of Claims 1 to 4, characterized in that polycondensation is carried out in a carbon dioxide atmosphere.
References Cited (Backward Citations)
No citation records indexed.
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