US4127718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tris-tetrazoles as chemical blowing agents
Assignee: BASF Corp
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Filing: 1977-10-05
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Granted: 1978-11-28
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Expires: 1997-10-05
Abstract
Abstract Tris-tetrazoles of formula I, ##STR1## wherein A is alkylene and R is hydrogen, alkyl or phenyl, are suitable blowing agents for thermoplastic resins, especially for polycarbonates and aromatic polyethers. The foaming process can be carried out at a temperature range of 230 to 300° C, the resulting foamed articles have a fine and homogenous cellular structure. The tris-tetrazoles I can be sythesized from the corresponding tris-nitriles or tris-imidchlorides by reaction with an alkali azide.
Inventors
- 👤 Hugo Illy
- 👤 Werner Fussenegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:32
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08J9/108
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
43 words
A tris-tetrazole of the formula I ##STR5## wherein A represents an alkylene radical of the formula --CH 2 --, --CH 2 --CH 2 -- or --CH(CH 3 )--CH 2 --, and R represents hydrogen, alkyl of 1 to 4 carbon atoms or phenyl.
Claim 2
Dependent Claim
43 words
A tris-tetrazole of the formula I ##STR5## wherein A represents an alkylene radical of the formula --CH 2 --, --CH 2 --CH 2 -- or --CH(CH 3 )--CH 2 --, and R represents hydrogen, alkyl of 1 to 4 carbon atoms or phenyl.
Claim 3
Dependent Claim
14 words
A compound according to claim 1, of the formula I, wherein R represents hydrogen.
Claim 4
Dependent Claim
20 words
The compound according to claim 1, of the formula I, wherein A represents --CH 2 --, and R represents hydrogen.
Claim 5
Dependent Claim
22 words
The compound according to claim 1, of the formula I, wherein A represents --CH 2 --CH 2 --, and R represents hydrogen.
References Cited (Backward Citations)
US3442829A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-27 | 1982-05-29 | 1982-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-27 | 1986-05-29 | 1986-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-27 | 1990-05-29 | 1990-11-28 | $7700.00 | Window Closed / Lapsed |