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US4520071A
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Spherical porous polyimide powder
Assignee: Nitto Denko Corp
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Filing: 1984-06-04
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Granted: 1985-05-28
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Expires: 2004-06-04
Abstract
Abstract A spherical porous polyimide powder which is thermally infusible and is insoluble in an organic solvent, comprising spherical porous particles of a weight average particle diameter of 1 to 20 μm comprising an aromatic polyimide having an inherent viscosity measured in sulfuric acid at a concentration of 0.5 g/dl at temperature of 30±0.01° C. of 0.1 to 2.0, wherein a packed bulk density is 100 to 600 g/l and a specific surface area measured by a nitrogen absorption method is 1 m 2 /g or more.
Inventors
- 👤 Yuzuru Noda
- 👤 Toshio Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:03
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/02; C08J2379/00; C08J2379/04; C08J2379/08; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A spherical porous polyimide powder which is thermally infusible and is insoluble in an organic solvent, comprising spherical porous particles of a weight average particle diameter of 1 to 20 μm comprising an aromatic polyimide having an inherent viscosity measured in sulfuric acid at a concentration of 0.5 g/dl at temperature of 30±0.01° C. of 0.1 to 2.0, wherein a packed bulk density is 100 to 600 g/l and a specific surface area measured by a nitrogen absorption method is 1 m 2 /g or more.
Claim 2
Dependent Claim
86 words
A spherical porous polyimide powder which is thermally infusible and is insoluble in an organic solvent, comprising spherical porous particles of a weight average particle diameter of 1 to 20 μm comprising an aromatic polyimide having an inherent viscosity measured in sulfuric acid at a concentration of 0.5 g/dl at temperature of 30±0.01° C. of 0.1 to 2.0, wherein a packed bulk density is 100 to 600 g/l and a specific surface area measured by a nitrogen absorption method is 1 m 2 /g or more.
Claim 3
Dependent Claim
21 words
The spherical porous polyimide powder as claimed in claim 1, wherein the weight average particle diameter is 1 to 15 μm.
Claim 4
Dependent Claim
21 words
The spherical porous polyimide powder as claimed in claim 1, wherein the weight average particle diameter is 1 to 10 μm.
Claim 5
Dependent Claim
18 words
The spherical porous polyimide powder as claimed in claim 1, wherein the inherent viscosity is 0.2 to 1.0.
Claim 6
Dependent Claim
18 words
The spherical porous polyimide powder as claimed in claim 1, wherein the inherent viscosity is 0.3 to 0.8.
Claim 7
Dependent Claim
20 words
The spherical porous polyimide powder as claimed in claim 1, wherein the packed bulk density is 200 to 500 g/l.
Claim 8
Dependent Claim
20 words
The spherical porous polyimide powder as claimed in claim 1, wherein the packed bulk density is 300 to 400 g/l.
Claim 9
Dependent Claim
22 words
The spherical porous polyimide powder as claimed in claim 1, wherein the specific surface area is 10 m 2 /g or more.
Claim 10
Dependent Claim
22 words
The spherical porous polyimide powder as claimed in claim 1, wherein the specific surface area is 100 m 2 /g or more.
Claim 11
Dependent Claim
22 words
The spherical porous polyimide powder as claimed in claim 1, wherein the specific surface area is up to 500 m 2 /g.
References Cited (Backward Citations)
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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) | 1988-05-27 | 1988-11-26 | 1989-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-27 | 1992-11-26 | 1993-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-27 | 1996-11-26 | 1997-05-28 | $7700.00 | Window Closed / Lapsed |