Patent US5412331A successfully refreshed from Google Patents.
Patent US4568412A successfully refreshed from Google Patents.
US4568412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface conductive polyimide
Assignee: EIDP Inc
•
Filing: 1984-11-01
•
Granted: 1986-02-04
•
Expires: 2004-11-01
Abstract
Abstract A process is disclosed for treating the surface of a shaped article of polyimide matrix material and finely-divided conductive carbon dispersed material whereby the electrical surface conductivity is increased by a factor of more than a million-fold.
Inventors
- 👤 George M. Atkins, Jr.
- 👤 Darrell J. Parish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:10
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/20; H01B1/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
A process for increasing the surface conductivity of a shaped article having polyimide as a matrix and carbon dispersed in the matrix comprising the steps of: (a) exposing at least one surface of the article to an etchant solution of an aqueous or alcoholic solution of a basic material for a time sufficient to remove a surface layer of the polyimide; (b) rinsing the exposed surface with an aqueous or alcoholic liquid to remove the etchant; and (c) drying the rinsed surface.
Claim 2
Dependent Claim
82 words
A process for increasing the surface conductivity of a shaped article having polyimide as a matrix and carbon dispersed in the matrix comprising the steps of: (a) exposing at least one surface of the article to an etchant solution of an aqueous or alcoholic solution of a basic material for a time sufficient to remove a surface layer of the polyimide; (b) rinsing the exposed surface with an aqueous or alcoholic liquid to remove the etchant; and (c) drying the rinsed surface.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the solution of step (a) has, as a solvent, water and a lower alcohol and, as a solute, potassium hydroxide.
Claim 4
Dependent Claim
31 words
The process of claim 2 wherein the solution of step (a) is from about 1 to 2 normal potassium hydroxide in an aqueous solvent of 50 to 90 weight percent ethanol.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the liquid of step (b) is water.
Claim 6
Dependent Claim
74 words
A process for increasing the surface conductivity of a film having polyimide as a matrix and from 10 to 90 weight percent finely-divided carbon substantially homogeneously dispersed throughout the matrix including immersing the film in an etchant solution of about 1 to 2 normal basic material in an aqueous solvent of 50 to 90 weight percent lower alcohol, rinsing the film with an aqueous liquid to remove the etchant, and drying the rinsed film.
Claim 7
Dependent Claim
74 words
A process for increasing the surface conductivity of a film having polyimide as a matrix and from 10 to 90 weight percent finely-divided carbon substantially homogeneously dispersed throughout the matrix including immersing the film in an etchant solution of about 1 to 2 normal basic material in an aqueous solvent of 50 to 90 weight percent lower alcohol, rinsing the film with an aqueous liquid to remove the etchant, and drying the rinsed film.
References Cited (Backward Citations)
US3791848A
Cited
US4298424A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |