US3625873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyimide hollow spheres
Assignee: Monsanto Research Corp
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Filing: 1967-11-09
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Granted: 1971-12-07
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Expires: 1987-11-09
Abstract
Abstract A method of making polyimide hollow spheres from a tetracarboxylic acid-ditertiary amine reaction product and an aromatic diamine in an aqueous solution.
Inventors
- 👤 Glenn R Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:18
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; B; B29; B29C; B29C44/00; B29C44/02; B29C44/10; C08G73/1003; C08G73/1007; C08J; C08J9/00; C08J9/32; Y; Y10; Y10S; Y10S264/00; Y10S264/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
21 words
The method defined in claim 1 wherein the diameter of the curable hollow spheres is from 0.01 mm. to 1.0 mm.
Claim 2
Dependent Claim
24 words
The method defined in claim 1 wherein the curable hollow spheres are further headed to about 350* C. to obtain fully cured hollow spheres.
Claim 3
Dependent Claim
9 words
The method defined in claim 1 wherein R is
Claim 4
Dependent Claim
10 words
The method defined in claim 1 wherein Z is phenylene.
Claim 5
Dependent Claim
10 words
The method as defined in claim 1 wherein R is
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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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |