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US4978737A Expired / Lapsed US ⏱️ 0.0 years remaining

Copolyimides derived from 2,2-bis (amino phenyl) hexofluoropropane

Assignee: Hoechst Celanese Chemical Co
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Filing: 1988-07-12
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Granted: 1990-12-18
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Expires: 2008-07-12
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Abstract

Abstract Polyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine and pyromellitic dianhydride (PMDA) can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride (ODPA), 3,3'4,4' benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4' diphenyl tetracarboxylic acid dianhydride (BPDA) and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350° C.) and have superior electrical properties, for example, dielectric constant of less than about 2.5 at 10 megahertz.

Inventors

  • 👤 Rohitkumar H. Vora

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 06:40
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1042

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 102 words
A polyimide polymer soluble in N-methyl pyrrolidone consisting essentially of the imidized condensation product of: (a) a diamine selected from the group consisting of 2,2-bis(3-aminophenyl)hexafluoropropane and 2,2,-bis(4-aminophenyl)hexafluoropropane; and a mixture of dianydrides comprising: (b) pyromellitic dianhydride; and (c) at least one additional dianhydride selected from the group consisting of bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3',4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis (3,4 dicarboxy phenyl) hexafluoropropane dianhydride the relative proportions of said dianhydrides present in the mixture being from about 35 to about 75 mole percent of (b) and from about 25 to about 65 mole percent of (c).
Claim 2
Dependent Claim 102 words
A polyimide polymer soluble in N-methyl pyrrolidone consisting essentially of the imidized condensation product of: (a) a diamine selected from the group consisting of 2,2-bis(3-aminophenyl)hexafluoropropane and 2,2,-bis(4-aminophenyl)hexafluoropropane; and a mixture of dianydrides comprising: (b) pyromellitic dianhydride; and (c) at least one additional dianhydride selected from the group consisting of bis (3,4-dicarboxyphenyl) ether dianhydride, 3,3',4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis (3,4 dicarboxy phenyl) hexafluoropropane dianhydride the relative proportions of said dianhydrides present in the mixture being from about 35 to about 75 mole percent of (b) and from about 25 to about 65 mole percent of (c).
Claim 3
Dependent Claim 16 words
The polyimide of claim 1 having a glass transition temperature of at least about 350° C.
Claim 4
Dependent Claim 22 words
The polyimide of claim 1 having a weight loss at 343° C. after 235 hours of not greater than about 3.0 percent.
Claim 5
Dependent Claim 22 words
The polyimide of claim 1 wherein said mixture of dianhydrides are present at a ratio of about 50 mole percent of each.
Claim 6
Dependent Claim 13 words
The polyimide of claim 1 wherein said diamine is 2,2 bis (4-aminophenyl) hexafluoropropane.
Claim 7
Dependent Claim 16 words
The polyimide of claim 5 wherein said additional dianhydride is 2,2 bis (3,4 dicarboxyphenyl) hexafluoropropane dianhydride.
Claim 8
Dependent Claim 22 words
The polyimide of claim 6 wherein said mixture of dianhydrides are present at a ratio of about 50 mole percent of each.
Claim 9
Dependent Claim 16 words
The polyimide of claim 1 having a glass transition temperature of at least about 350° C.
Claim 10
Dependent Claim 17 words
The polyimide of claim 1 having a dielectric constant of less than about 2.5 at 10 megahertz.
Claim 11
Dependent Claim 11 words
A solution of the polyimide of claim 1 in organic solvent.
Claim 12
Dependent Claim 18 words
A film prepared by coating the solution of claim 10 a suitable substrate, and evaporating off the solvent.
Claim 13
Dependent Claim 9 words
A fiber prepared from the copolyimide of claim 1.
Claim 14
Dependent Claim 12 words
A composite comprising the polyimide of claim 1 mixed with reinforcing fibers.

References Cited (Backward Citations)

GB1062435A Cited
US3424718A Cited
US3356648A Cited
US4612361A Cited
US4886874A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-12-17 1994-06-18 1994-12-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-12-17 1998-06-18 1998-12-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-12-17 2002-06-18 2002-12-18 $7700.00 Window Closed / Lapsed

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