US3952084A
Expired / Lapsed
US
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Polyimide and polyamide-imide precursors prepared from esters, dianhydrides, and diisocyanates
Assignee: Westinghouse Electric Corp
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Filing: 1974-10-22
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Granted: 1976-04-20
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Expires: 1994-10-22
Abstract
Abstract A solution is prepared of about 30 to about 60 mole percent of a mono-ester of a tricarboxylic anhydride or a diester of a tetracarboxylic acid and about 40 to about 70 mole percent of a dianhydride. An aromatic diisocyanate is added and the solution heated until the viscosity no longer increases. The precursor can be precipitated by the addition of a non-solvent, collected, and re-dissolved in a solvent. The solution of the precursor can be applied to a sheet and cured to form a polyimide or polyamide-imide film, or it can be applied to a wire and cured to form a polyimide or polyamide-imide wire enamel.
Inventors
- 👤 Leonard E. Edelman
- 👤 William M. Alvino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:43
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1035; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/2942; Y10T428/2949; Y10T428/31504; Y10T428/31678; Y10T428/31681
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
81 words
A composition comprising a solution of: A. about 30 to about 60 mole percent of an ester selected from the group consisting of 1. mono-esters of tricarboxylic anhydride; 2. diesters of a tetrocarboxylic acid where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and 3. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; and C. an aromatic diisocyanate in an amount within 5 mole percent of stoichiometric.
Claim 2
Dependent Claim
81 words
A composition comprising a solution of: A. about 30 to about 60 mole percent of an ester selected from the group consisting of 1. mono-esters of tricarboxylic anhydride; 2. diesters of a tetrocarboxylic acid where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and 3. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; and C. an aromatic diisocyanate in an amount within 5 mole percent of stoichiometric.
Claim 3
Dependent Claim
11 words
A composition according to claim 1 wherein said dianhydride is aromatic.
Claim 4
Dependent Claim
12 words
A composition according to claim 2 wherein said dianhydride is pyromellitic dianhydride.
Claim 5
Dependent Claim
15 words
A composition according to claim 1 wherein the amount of said aromatic diisocyanate is stoichiometric.
Claim 6
Dependent Claim
21 words
A composition according to claim 1 wherein said diisocyanate is selected from the group consisting of p,p'-diisocyanatodiphenylether, p,p'-diisocyanatodiphenylmethane, and mixtures thereof.
Claim 7
Dependent Claim
19 words
A composition according to claim 1 wherein said ester groups are alkyl from C 1 to C 4 .
Claim 8
Dependent Claim
27 words
A composition according to claim 1 wherein the amount of the solvent forming said folution is about 2 to about 5 times the weight of said dianhydride.
Claim 9
Dependent Claim
17 words
A composition according to claim 1 wherein said solution is at about 5 to about 25% solids.
Claim 10
Dependent Claim
15 words
A composition according to claim 1 wherein the solvent for said solution is N-methyl pyrrolidone.
Claim 11
Dependent Claim
15 words
A composition according to claim 1 wherein said ester is an ester of trimellitic anhydride.
Claim 12
Dependent Claim
15 words
A composition according to Claim 1 wherein said ester is an ester of pyromellitic dianhydride.
Claim 13
Dependent Claim
82 words
The uncured reaction product of A. about 30 to about 30 mole percent of an ester selected from the group consisting of 1. monoesters of a tricarboxylic anhydride; 2. diesters of a tetracarboxylic acid, where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and 3. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; and C. an aromatic diisocyanate in an amount within about 5 mole percent of stoichiometric.
Claim 14
Dependent Claim
82 words
The uncured reaction product of A. about 30 to about 30 mole percent of an ester selected from the group consisting of 1. monoesters of a tricarboxylic anhydride; 2. diesters of a tetracarboxylic acid, where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and 3. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; and C. an aromatic diisocyanate in an amount within about 5 mole percent of stoichiometric.
Claim 15
Independent Claim
98 words
A method of making a polyimide precursor comprising: 1. preparing a solution of A. about 30 to about 60 mole percent of an ester selected from the group consisting of i. monoesters of a tricarboxylic anhydride; ii. diesters of a tetracarboxylic acid, where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and iii. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; 2. adding to said solution an aromatic diisocyanate in an amount within about 5 mole percent of stoichiometric; and 3. heating said solution.
Claim 16
Independent Claim
98 words
A method of making a polyimide precursor comprising: 1. preparing a solution of A. about 30 to about 60 mole percent of an ester selected from the group consisting of i. monoesters of a tricarboxylic anhydride; ii. diesters of a tetracarboxylic acid, where the ester groups are non-vicinal and each ester group is vicinal to a different carboxylic acid group; and iii. mixtures thereof; B. about 40 to about 70 mole percent of a dianhydride; 2. adding to said solution an aromatic diisocyanate in an amount within about 5 mole percent of stoichiometric; and 3. heating said solution.
Claim 17
Dependent Claim
41 words
A method according to claim 13 including the additional final steps of: 1. adding a non-solvent to said solution to cause said precursor to precipitate 2. collecting said precipitated precursor; and 3. re-dissolving said collected precipitated precursor in a precursor solvent.
Claim 18
Dependent Claim
53 words
A method according to claim 14 wherein the amount of said non-solvent is about 10 to about 100% by volume of the volume of said admixture, and the amount of said precursor solvent is sufficient to make a solution of about 70 to about 82% solvent and about 18 to about 30% precursor.
Claim 19
Dependent Claim
42 words
A method according to claim 14 including the additional final steps making a polyimide from said polyimide precursor by 1. applying the solution of the precursor to a surface; 2. heating said solution to evaporate said solvent and to cure said precursor.
Claim 20
Dependent Claim
24 words
A method according to claim 16 wherein said surface is a flat, horizontal sheet and said polyimide is in the form of a film.
Claim 21
Dependent Claim
21 words
A method according to claim 16 wherein said surface is a wire and said polyimide forms an enamel on said wire.
Claim 22
Dependent Claim
24 words
A method according to claim 16 wherein: said heating is done at about 275° to about 300°C for about 30 to about 45 minutes.
Claim 23
Dependent Claim
13 words
An uncured reaction product according to claim 12 wherein said dianhydride is aromatic.
Claim 24
Dependent Claim
14 words
An uncured reaction production according to claim 20 wherein said dianhydride is pyromellitic dianhydride.
Claim 25
Dependent Claim
17 words
An uncured reaction product according to claim 12 wherein the amount of said aromatic diisocyanate is stoichiometric.
Claim 26
Dependent Claim
24 words
An uncured reaction product according to claim 12 wherein said diisocyanate is selected from the group consisting of p,p' -diisocyanatodiphenylether, p,p'-diisocyanatodiphenylmethane, and mixtures thereof.
Claim 27
Dependent Claim
21 words
An uncured reaction product according to claim 12 wherein said ester groups are alkyl from C 1 to C 4 .
Claim 28
Dependent Claim
13 words
An uncured reaction product according to claim 1 wherein said ester is aromatic.
Claim 29
Dependent Claim
17 words
An uncured reaction product according to claim 25 wherein said ester is an ester of trimellitic anhydride.
Claim 30
Dependent Claim
17 words
An uncured reaction product according to claim 12 wherein said ester is an ester of pyromellitic dianhydride.
Claim 31
Dependent Claim
11 words
A composition according to claim 1 wherein said ester is aromatic.
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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) | 1979-04-20 | 1979-10-20 | 1980-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-20 | 1983-10-20 | 1984-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-20 | 1987-10-20 | 1988-04-20 | $7700.00 | Window Closed / Lapsed |