Patent US5401077A successfully refreshed from Google Patents.
Patent US5648032A successfully refreshed from Google Patents.
US5648032A
Expired / Lapsed
US
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Process for producing polyester articles having low acetaldehyde content
Assignee: Grupo Petrotemex SA de CV
•
Filing: 1995-08-01
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Granted: 1997-07-15
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Expires: 2015-08-01
Abstract
Abstract Disclosed is a process for producing molded polyester articles having a low acetaldehyde content by a) reacting a glycol and a dicarboxylic acid in the melt phase to form a polyester having an I.V. of about 0.65-0.85, b) solidifying and pelletizing said polyester, c) remelting said polyester in an extruder, and, d) forming said polyester into shaped articles, wherein the polyester is devolatilized during or following said polymerization in the melt, while it is being remelted, after remelting, or any combination by passing a purge gas over said molten polyester.
Inventors
- 👤 Gregory Wayne Nelson
- 👤 Vincent Alvin Nicely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:02
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/88; C08G63/90; B; B29; B29K; B29K2105/00; B29K2105/0002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
143 words
A process for producing molded polyester articles having an acetaldehyde content of less than about 10 ppm comprising the steps of a) reacting a glycol and a dicarboxylic acid in the melt phase to form a polyester having in I.V. of about 0.65-0.85, said glycol being selected from the class consisting of glycols having 2-10 carbon atoms and said dicarboxylic acid being selected from alkyl dicarboxylic acids having 2-16 carbon atoms and aryl dicarboxylic acids having 8-16 carbon atoms, b) solidifying and pelletizing said polyester, c) remelting said polyester to form molten polyester, and d) forming said molten polyester into shaped articles, wherein, during step a), step b). step c), step d), or a combination thereof, the polyester is devolatilized by passing a purge agent over said polyester, wherein no solid state polymerization step is performed and wherein no drying step is performed.
Claim 2
Dependent Claim
143 words
A process for producing molded polyester articles having an acetaldehyde content of less than about 10 ppm comprising the steps of a) reacting a glycol and a dicarboxylic acid in the melt phase to form a polyester having in I.V. of about 0.65-0.85, said glycol being selected from the class consisting of glycols having 2-10 carbon atoms and said dicarboxylic acid being selected from alkyl dicarboxylic acids having 2-16 carbon atoms and aryl dicarboxylic acids having 8-16 carbon atoms, b) solidifying and pelletizing said polyester, c) remelting said polyester to form molten polyester, and d) forming said molten polyester into shaped articles, wherein, during step a), step b). step c), step d), or a combination thereof, the polyester is devolatilized by passing a purge agent over said polyester, wherein no solid state polymerization step is performed and wherein no drying step is performed.
Claim 3
Dependent Claim
17 words
Process according to claim 1 wherein the polyester from step a) has an I.V. of about 0.70-0.80.
Claim 4
Dependent Claim
13 words
Process according to claim 1 wherein said polyester is devolatilized in an extruder.
Claim 5
Dependent Claim
15 words
A process according to claim 1 wherein said polyester is crystallized prior to step c).
Claim 6
Dependent Claim
19 words
Process according to claim 1 wherein the polyester has a final residual acetaldehyde content of less than 5 ppm.
Claim 7
Dependent Claim
18 words
Process according to claim 1 wherein at least 80 mol % of said dicarboxylic acid is terephthalic acid.
Claim 8
Dependent Claim
19 words
Process according to claim 1 wherein at least 80 mol % of said dicarboxylic acid is naphthalene dicarboxylic acid.
Claim 9
Dependent Claim
17 words
Process according to claim 1 wherein at least 80 mol % of said glycol is ethylene glycol.
Claim 10
Dependent Claim
16 words
Process according to claim 1 wherein said glycol is a mixture of ethylene glycol and cyclohexanedimethanol.
Claim 11
Dependent Claim
30 words
Process according to claim 1 wherein said acid is terephthalic acid and said glycol is a mixture of about 60-99 mol % ethylene glycol and about 40-1 mol % cyclohexanedimethanol.
Claim 12
Dependent Claim
22 words
Process according to claim 4 wherein the polyester is remelted and devolatilized in an extruder during, following, or during and following remelting.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-07-14 | 2001-01-13 | 2001-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-14 | 2005-01-13 | 2005-07-15 | $3760.00 | Window Closed / Lapsed |
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