US4472567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polyamide imides
Assignee: Bayer AG
•
Filing: 1983-08-22
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Granted: 1984-09-18
•
Expires: 2003-08-22
Abstract
Abstract The condensation of organic polyisocyanates, lactams, and cyclic polycarboxylic acid anhydrides in the presence of mono- or disubstituted imidazole catalyst results in a polyamide imide having an increased softening temperature.
Inventors
- 👤 Wilfried Zecher
- 👤 Rudolf Merten
- 👤 Willi Dunwald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:27
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/14; C08G18/00; C08G18/06; C08G18/08; C08G18/16; C08G18/18; C08G18/20; C08G18/2009; C08G18/2027; C08G18/28; C08G18/2805; C08G18/285; C08G18/2855; C08G18/30; C08G18/34; C08G18/343
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
51 words
In the process for production of polyamide imide by condensation of organic polyisocyanates, lactams and cyclic polycarboxylic acid anhydrides at temperatures of from 0° to 450° C., the improvement comprises carrying out the condensation in the presence of 0.01 to 5% by weight of a monosubstituted or disubstituted imidazole as catalyst.
Claim 2
Dependent Claim
51 words
In the process for production of polyamide imide by condensation of organic polyisocyanates, lactams and cyclic polycarboxylic acid anhydrides at temperatures of from 0° to 450° C., the improvement comprises carrying out the condensation in the presence of 0.01 to 5% by weight of a monosubstituted or disubstituted imidazole as catalyst.
Claim 3
Dependent Claim
49 words
A process as claimed in claim 1, characterised in that a pre-condensate of polyisocyanate, cyclic carboxylic acid anhydride and lactam is prepared at a temperature of from 50° to 220° C. and, after addition of the catalyst, is further reacted at a temperature of from 170° to 450° C.
Claim 4
Dependent Claim
103 words
A process as claimed in claim 1, characterised in that a substituted imidazole corresponding to the following general formula: ##STR4## wherein R 2 represents a straight- or branched-chain alkyl radical containing from 1 to 20 carbon atoms which may optionally be substituted by an aromatic radical containing 6 carbon atoms; and R 3 represents hydrogen, an alkyl radical containing from 1 to 20 carbon atoms, an aralkyl radical containing from 6 to 10 carbon atoms in the aryl portion and from 1 to 10 carbon atoms in the alkyl portion or an aryl radical containing from 6 to 10 carbon atoms is used.
Claim 5
Dependent Claim
16 words
A process as claimed in claim 1, characterised in that 2-methyl imidazole is used as catalyst.
Claim 6
Dependent Claim
20 words
A process as claimed in claims 1 or 2, characterised in that the reaction is carried out in a solvent.
Claim 7
Dependent Claim
15 words
A process as claimed in claim 1, characterised in that a phenolic solvent is used.
Claim 8
Dependent Claim
100 words
A process as claimed in claim 1, characterised in that a cyclic polycarboxylic acid anhydride corresponding to the following general formula: ##STR5## wherein R 1 represents an optionally substituted C 2 -C 20 aliphatic radical, a C 5 -C 10 cycloaliphatic radical, an aliphatic-aromatic radical containing from 1 to 10 carbon atoms in the aliphatic portion and from 6 to 10 carbon atoms in the aromatic portion or an aromatic radical containing from 6 to 10 carbon atoms, which in addition to the cyclic anhydride group contains at least one other cyclic anhydride group or a carboxyl group; is used.
Claim 9
Dependent Claim
21 words
A process as claimed in claim 1, characterised in that trimellitic acid anhydride is used as the cyclic carboxylic acid anhydride.
Claim 10
Dependent Claim
11 words
Polycondensates obtained by the process claimed in claims 1 or 2.
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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |