US3621074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of a modified diglycol therephthalate polycondensate for injection molding
Assignee: Glanzstoff AG
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Filing: 1968-11-22
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Granted: 1971-11-16
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Expires: 1988-11-22
Abstract
Abstract Process of producing a polycondensate of a diglycol terephthalate especially suitable for injection molding purposes wherein the usual catalytic polycondensation is carried out after the incorporation of 0.1 to 5 percent by weight of a diglycidyl ether as a monomeric coreactant up to a solution viscosity of 1.4 to 1.8, at which point the polycondensate melt is immediately cooled and solidified, the product then being further condensed in the solid phase under an inert atmosphere at temperatures of 180* to 230* C. until the melt index of the product acquires a value of between 50 and 0.5 grams/10 minutes.
Inventors
- 👤 Erhard Siggel
- 👤 Walter Rein
- 👤 Horst-Manfred Caesar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:18
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/42; C08L; C08L67/00; C08L67/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
15 words
A process as claimed in claim 1 wherein the diglycol terephthalate is diethylene glycol terephthalate.
Claim 2
Dependent Claim
28 words
A process as claimed in claim 1 wherein the polycondensation reaction mixture is solidified in step (B) after it has attained a solution viscosity of 1.6 to 1.8.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 3 wherein the diglycol terephthalate is diethylene glycol terephthalate.
Claim 4
Dependent Claim
33 words
A process as claimed in claim 1 wherein said further condensation in step (C) is carried out until the solid product has a melt index of between about 1 and 20 grams/10 minutes.
Claim 5
Dependent Claim
38 words
A process as claimed in claim 1 wherein the solid product of step (B) is homogeneously admixed with about 0.5 to 20 percent by weight thereof a polyolefin with the mixture being regranulated before carrying out step (C).
Claim 6
Dependent Claim
16 words
A process as claimed in claim 1 wherein said diglycidyl ether is an epoxidized 2,2-bis-4-hydroxyphenyl propane.
Claim 7
Dependent Claim
41 words
A process as claimed in claim 1 wherein the monomeric mixture being polycondensed in step (A) is obtained by transesterification of dimethyl terephthalate with ethylene glycol, and said diglycidyl ether is added at least at the beginning of the polyconsation reaction.
Claim 8
Dependent Claim
29 words
A process as claimed in claim 1 wherein the solid product of step (B) is reduced to particulate form before being subjected to said further condensation in step (C).
Claim 9
Dependent Claim
9 words
The product obtained by the process of claim 1.
Claim 10
Dependent Claim
21 words
A process as claimed in claim 6 wherein said polyolefin is selected from the group consisting of polypropylene, poly-4-methylpentene1 and polyethylene.
Claim 11
Dependent Claim
20 words
A process as claimed in claim 11 wherein said polyolefin is polyethylene having a density of from 0.915 to 0.930.
References Cited (Backward Citations)
US2998408A
Cited
US2901466A
Cited
GB872254A
Cited
US3372143A
Cited
DE1251950B
Cited
US3390134A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |