US4578433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Long-term stability of the electrical conductivity of pyrrole polymers
Assignee: BASF SE
•
Filing: 1984-12-20
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Granted: 1986-03-25
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Expires: 2004-12-20
Abstract
Abstract The long-term stability of the electrical conductivity of pyrrole polymers is improved by a process in which the polymers are treated with an aqueous acid. Pyrrole polymers treated in this manner are used as conductor elements in the electrical industry.
Inventors
- 👤 Helmut Muenstedt
- 👤 Herbert Naarmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:15
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/06; H01B1/12; H01B1/124; H01B1/128; C; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
29 words
A process for improving the long-term stability of the electrical conductivity of a pyrrole polymer, wherein the polymer is subsequently treated with an aqueous acid as a separate step.
Claim 2
Dependent Claim
29 words
A process for improving the long-term stability of the electrical conductivity of a pyrrole polymer, wherein the polymer is subsequently treated with an aqueous acid as a separate step.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1, wherein the aqueous acid used has a pH of less than 4.
Claim 4
Dependent Claim
18 words
A process as claimed in claim 1, wherein the aqueous acid used is sulfuric acid or hydrochloric acid.
Claim 5
Dependent Claim
14 words
A process as claimed in claim 1, wherein 0.1-25% strength sulfuric acid is used.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 1, wherein the polymer is subsequently treated with an alkali metal hydroxide solution.
Claim 7
Dependent Claim
16 words
The process of claim 1, wherein the pyrrole polymer is in the form of a film.
References Cited (Backward Citations)
US3574072A
Cited
US4487667A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-24 | 1989-09-23 | 1990-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-24 | 1993-09-23 | 1994-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-24 | 1997-09-23 | 1998-03-25 | $7700.00 | Window Closed / Lapsed |