US3954716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polyesters
Assignee: Bayer AG
•
Filing: 1974-11-12
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Granted: 1976-05-04
•
Expires: 1994-11-12
Abstract
Abstract High molecular weight polyesters are prepared by reacting cyclic acetals or ketals with carboxylic acids or low molecular weight carboxyl terminated polyesters while avoiding the necessity of removing by-products of condensation such as water or alcohols. The polyesters of the invention are useful in the polyisocyanate polyaddition process or as plasticizers for polyvinylchloride and other synthetic resins.
Inventors
- 👤 Erwin Muller
- 👤 Normann Joop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:40
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/42
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
A process for the preparation of a polyester with a molecular weight above 10,000 which comprises the step of heating to a temperature of 130°-220°C a mixture consisting essentially of an aliphatic or carbocyclic aromatic polyester having only two free carboxylic acid groups and having an acid number of from about 50 to about 200 and a cyclic ether selected from the group consisting of: ##SPC3##
Claim 2
Dependent Claim
66 words
A process for the preparation of a polyester with a molecular weight above 10,000 which comprises the step of heating to a temperature of 130°-220°C a mixture consisting essentially of an aliphatic or carbocyclic aromatic polyester having only two free carboxylic acid groups and having an acid number of from about 50 to about 200 and a cyclic ether selected from the group consisting of: ##SPC3##
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said reaction is carried out in the presence of a catalytic amount of an esterification or ester interchange catalyst.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein said catalyst is p-toluenesulphonic acid.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein said reaction is carried out in the melt.
Claim 6
Dependent Claim
22 words
The process of claim 1 wherein said reaction is carried out; in a stream of gas which is inert to the reactants.
References Cited (Backward Citations)
GB843825A
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GB891206A
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GB1016076A
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GB992989A
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US3225014A
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US3225015A
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GB1000329A
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US3644484A
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US3739017A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-04 | 1979-11-03 | 1980-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-04 | 1983-11-03 | 1984-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-04 | 1987-11-03 | 1988-05-04 | $7700.00 | Window Closed / Lapsed |