US4434276A
Expired / Lapsed
US
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Process for the condensation of poly(alkylene terephthalates)
Assignee: Huels AG
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Filing: 1983-03-31
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Granted: 1984-02-28
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Expires: 2003-03-31
Abstract
Abstract A process for the post condensation of poly(alkylene terephthalate) in the solid phase is carried out in the presence of esters of phosphorous acid at 25°-65° C. below the melting point of the poly(alkylene terephthalate) while passing an inert gas stream through the reaction mixture.
Inventors
- 👤 Gernot Horlbeck
- 👤 Horst Heuer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:31
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/87; C08G63/80; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/52; C08K5/524
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
146 words
A process for further condensing a linear poly(alkylene terephthalate) having a viscosity number of at least 50 cm 3 /g in the solid phase at an elevated temperature, comprising condensing the poly(alkylene terephthalate) in an inert gas stream at a temperature 25°-65° C. below the melting point of the poly(alkylene terephthalate) and in the presence of 0.5-5% by weight, based on the amount of poly(alkylene terephthalate), of a phosphorous acid ester of the formula P(OR 1 )(OR 2 )(OR 3 ) wherein each of R 1 , R 2 and R 3 is independently C 1-12 alkyl, C 6-10 -aryl, C 5-12 -cycloalkyl, or C 6-10 -aryl or C 5-12 -cycloalkyl each substituted by C 1-12 -alkyl, cyclohexyl, phenyl or phenyl-C 1-12 -alkyl, wherein the amount of inert gas passed through the reactor per hour, measured under normal conditions, is 0.5-1.5 times the gross reactor volume.
Claim 2
Dependent Claim
146 words
A process for further condensing a linear poly(alkylene terephthalate) having a viscosity number of at least 50 cm 3 /g in the solid phase at an elevated temperature, comprising condensing the poly(alkylene terephthalate) in an inert gas stream at a temperature 25°-65° C. below the melting point of the poly(alkylene terephthalate) and in the presence of 0.5-5% by weight, based on the amount of poly(alkylene terephthalate), of a phosphorous acid ester of the formula P(OR 1 )(OR 2 )(OR 3 ) wherein each of R 1 , R 2 and R 3 is independently C 1-12 alkyl, C 6-10 -aryl, C 5-12 -cycloalkyl, or C 6-10 -aryl or C 5-12 -cycloalkyl each substituted by C 1-12 -alkyl, cyclohexyl, phenyl or phenyl-C 1-12 -alkyl, wherein the amount of inert gas passed through the reactor per hour, measured under normal conditions, is 0.5-1.5 times the gross reactor volume.
Claim 3
Dependent Claim
24 words
A process of claim 1, comprising condensing the poly(alkylene terephthalate) at a temperature 35°-55° C. below the melting point of the poly(alkylene terephthalate) used.
Claim 4
Dependent Claim
21 words
A process of claim 1 wherein the amount of the phosphorous acid ester is 1-3% by weight on the same basis.
Claim 5
Dependent Claim
22 words
A process of claim 1 wherein the amount of inert gas passed through per hour is 0.6-1.3 times the gross reactor volume.
Claim 6
Dependent Claim
38 words
A process of claim 1 wherein each of R 1 , R 2 and R 3 is alkyl and the total number of carbon atoms in R 1 , R 2 and R 3 is at least 12.
Claim 7
Dependent Claim
30 words
A process of claim 1 wherein R 1 , R 2 and R 3 are phenyl, α- or β-naphthyl, cyclopentyl, cyclohexyl, cyclododecyl, o-, m-, or p-methylphenyl, or 2,4- or 4,6-dimethylphenyl.
Claim 8
Dependent Claim
27 words
A process of claim 1 wherein R 1 , R 2 and R 3 are phenyl, α- or β-naphthyl, o-, m-, or p-methylphenyl or 2,4- or 4,6-dimethylphenyl.
Claim 9
Dependent Claim
20 words
A process of claim 1 wherein the phosphorous acid ester is triphenyl phosphite, tris(cresyl) phosphite, tris(tert-butylphenyl) phosphite, or tris(nonylphenyl) phosphite.
Claim 10
Dependent Claim
13 words
A process of claim 1 wherein the inert gas is N 2 .
Claim 11
Dependent Claim
15 words
A process of claim 1 wherein the poly(alkylene terephthalate) is poly(ethylene terephthalate) or poly(butylene terephthalate).
Claim 12
Dependent Claim
20 words
A process of claim 1 wherein the poly(alkylene terephthalate) has a viscosity number of at least 65 cm 3 /g.
Claim 13
Dependent Claim
12 words
A process of claim 1 wherein the reaction time is 3-10 hours.
Claim 14
Dependent Claim
10 words
A poly(alkylene terephthalate) produced by the process of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-27 | 1987-08-29 | 1988-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-27 | 1991-08-29 | 1992-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-27 | 1995-08-29 | 1996-02-28 | $7700.00 | Window Closed / Lapsed |