US4623563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polyimide/metallic foil composite film
Assignee: Nitto Denko Corp
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Filing: 1985-03-27
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Granted: 1986-11-18
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Expires: 2005-03-27
Abstract
Abstract A process for producing a polyimide/metallic foil composite film having a curvature radius of at least 25 cm and which is substantially free from curling is described, comprising coating a solution of a polyimide precursor in an organic polar solvent on a 1 to 500 μm thick metallic foil, the polyimide precursor being prepared by reacting a diamine component comprising p-phenylenediamine and an aromatic tetracarboxylic acid component comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride or its derivative; heat-drying the above-prepared coating in the state that the metallic foil is fixed; and then heating it at a high temperature to form a 5 to 200 μm thick polyimide film. This composite film does not substantially curl in either the lengthwise and widthwise directions and is very suitable for use in the production of an electric circuit board.
Inventors
- 👤 Yuzuru Noda
- 👤 Masanori Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:56
CPC Classifications
B; B05; B05D; B05D5/00; B05D5/12; B05D7/00; B05D7/14; B05D7/16; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0346; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/26; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31721
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
114 words
A process for producing a polyimide/metallic foil composite film having a curvature radius of at least 25 cm and which is substantially free from curling, which comprises: coating a solution of a polyimide precursor in an organic polar solvent onto a metallic foil having a thickness of from 1 to 500 μm, said polyimide precursor being prepared by reacting a diamine component comprising p-phenylenediamine with an aromatic tetracarboxylic acid component comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride or a derivative thereof; drying the resulting coating by heating in the state that the metallic foil is fixed; and heating the coating at a high temperature to produce a polyimide film having a thickness of from 2 to 200 μm.
Claim 2
Dependent Claim
114 words
A process for producing a polyimide/metallic foil composite film having a curvature radius of at least 25 cm and which is substantially free from curling, which comprises: coating a solution of a polyimide precursor in an organic polar solvent onto a metallic foil having a thickness of from 1 to 500 μm, said polyimide precursor being prepared by reacting a diamine component comprising p-phenylenediamine with an aromatic tetracarboxylic acid component comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride or a derivative thereof; drying the resulting coating by heating in the state that the metallic foil is fixed; and heating the coating at a high temperature to produce a polyimide film having a thickness of from 2 to 200 μm.
Claim 3
Dependent Claim
32 words
A process as in claim 1, wherein the logarithmic viscosity of the polyimide precursor (measured at 30° C. in N-methyl-2-pyrrolidone at a concentration of 0.5 g/100 ml) is from 0.4 to 7.0.
Claim 4
Dependent Claim
15 words
A process as in claim 2, wherein the logarithmic viscosity is from 1.5 to 3.0.
Claim 5
Dependent Claim
25 words
A process as in claim 1, wherein the diamine component comprises 80 mol% or more of p-phenylenediamine and 20 mol% of less of other diamine.
Claim 6
Dependent Claim
32 words
A process as in claim 4, wherein the other diamine is selected from the group consisting of 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylpropane, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 4,4'-diaminodiphenylsulfide, 4,4'-di(m-aminophenoxy)diphenylsulfone, 3,3'-di(m-aminophenoxy)diphenylsulfone, 4,4'-di(m-aminophenoxy)diphenylpropane and mixtures thereof.
Claim 7
Dependent Claim
36 words
A process as in claim 1, wherein the aromatic tetracarboxylic acid component comprises 70 mol% or more of 3,3',4,4'-biphenyltetracarboxylic dianhydride or its derivative and 30 mol% or less of other aromatic tetracarboxylic dianhydrides or derivatives thereof.
Claim 8
Dependent Claim
33 words
A process as in claim 6, wherein the other aromatic tetracarboxylic dianhydrides or derivatives thereof are selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid, derivatives thereof and mixtures thereof.
Claim 9
Dependent Claim
36 words
A process as in claim 1, wherein the reaction to prepare the polyimide precursor is conducted in an organic polar solvent at a temperature of from 0° to 90° C. for from 1 to 24 hours.
Claim 10
Dependent Claim
27 words
A process as in claim 8, wherein the organic polar solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, dimethylphosphoamide, m-cresol, p-cresol and p-chlorophenol.
Claim 11
Dependent Claim
24 words
A process as in claim 1, wherein the metallic foil is selected from the group consisting of a copper foil and an aluminum foil.
Claim 12
Dependent Claim
18 words
A process as in claim 1, wherein the metallic foil has the thickness of 10 to 100 μm.
Claim 13
Dependent Claim
27 words
A process as in claim 1, wherein the drying is conducted at a temperature of from 100° to 230° C. for from 30 minutes to 2 hours.
Claim 14
Dependent Claim
28 words
A process as in claim 1, wherein the final heating is conducted at a temperature of from 230° to 600° C. for from 1 minute to 6 hours.
Claim 15
Dependent Claim
30 words
A process as in claim 1, wherein the difference in the coefficients of linear thermal expansion between the metallic foil and the polyimide coating is 0.3×10 -5 /°C. or less.
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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) | 1989-11-17 | 1990-05-19 | 1990-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-17 | 1994-05-19 | 1994-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-17 | 1998-05-19 | 1998-11-18 | $7700.00 | Window Closed / Lapsed |