US4880699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrathin polyimide polymer films and their preparation
Assignee: CNA Holdings LLC
•
Filing: 1989-04-17
•
Granted: 1989-11-14
•
Expires: 2009-04-17
Abstract
Abstract Disclosed herein are free-standing, pinhole-free, ultrathin polyimide films having thicknesses of about 400 angstroms or less and a process to prepare them. The films find particular utility in separatory applications.
Inventors
- 👤 Rachel S. Kohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:06
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B01; B01D; B01D69/00; B01D69/12; B01D69/122; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; B29; B29C; B29C41/00; B29C41/003; C08G; C08G73/00; C08G73/06; C08G73/10; B29C41/02; B29C41/12; B29K; B29K2079/00; B29K2105/00; B29K2105/0058; B29K2105/0073; C08J2379/00; C08J2379/04; C08J2379/08; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/261; Y10T428/263; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
14 words
A pinhole-free, polyimide polymer film having a thickness of about 400 angstroms or less.
Claim 2
Dependent Claim
14 words
A pinhole-free, polyimide polymer film having a thickness of about 400 angstroms or less.
Claim 3
Dependent Claim
90 words
The film of claim 1 wherein the polyimide polymer has repeating units of the formula: ##STR8## wherein R is a tetravalent organic radical selected from the group consisting of aromatic, aliphatic, cycloaliphatic, heterocyclic, combinations of aromatic and aliphatic, and substituted groups thereof and wherein R' is a divalent benzenoid radical selected from the group consisting of: ##STR9## wherein R" is selected from the group consisting of an alkylene chain having one to three carbon atoms, ##STR10## wherein R'" and R"" are selected from the group consisting of alkyl and aryl.
Claim 4
Dependent Claim
66 words
The film of claim 2 wherein R is a tetravalent aromatic radical containing at least one ring of six carbon atoms, said ring being characterized by benzenoid unsaturation and the four carbonyl groups being attached directly to separate carbon atoms in a ring of the R radical and each pair of carbonyl groups being attached to adjacent carbon atoms in a ring of the R radical.
Claim 5
Dependent Claim
13 words
The film of claim 3 wherein R is ##STR11## and R' is ##STR12##
Claim 6
Dependent Claim
27 words
The film of claims 1, 2, 3 or 4 wherein the film is prepared from polyimide polymers having molecular weights, M w , greater than about 25,000.
Claim 7
Dependent Claim
21 words
The film of claims 1, 2, 3 or 4 wherein the film has a thickness of about 300 angstroms or less.
Claim 8
Dependent Claim
21 words
The film of claim 6 wherein the film has a thickness in the range of about 150 to about 300 angstroms.
Claim 9
Dependent Claim
18 words
The film of claims 1, 2, 3 or 4 wherein the film is crosslinked by heating the film.
Claim 10
Dependent Claim
25 words
The film of claim 8 wherein the film is heated in the range of about 250° C. to about 350° C. to crosslink the film.
Claim 11
Dependent Claim
21 words
The film of claim 9 wherein the film is heated at a temperature of about 290° C. to crosslink the film.
Claim 12
Dependent Claim
14 words
The film of claim 7 wherein the film is crosslinked by heating the film.
Claim 13
Dependent Claim
25 words
The film of claim 7 wherein the film is heated in the range of about 250° C. to about 350° C. to crosslink the film.
Claim 14
Dependent Claim
21 words
The film of claim 7 wherein the film is heated at a temperature of about 290° C. to crosslink the film.
References Cited (Backward Citations)
US2710853A
Cited
US3673145A
Cited
US3767737A
Cited
US4279855A
Cited
US3892665A
Cited
US4374891A
Cited
US4155793A
Cited
US4393113A
Cited
US4746474A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |