US4447589A
Expired / Lapsed
US
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Method for preparing polyamide-imide resin
Assignee: Resonac Corp
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Filing: 1982-11-04
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Granted: 1984-05-08
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Expires: 2002-11-04
Abstract
Abstract A polyamide-imide resin which can give a varnish having a high resin content, excellent in storage stability and heat resistant final products can be produced by reacting an aromatic diisocyanate with a tricarboxylic acid anhydride in the presence of a basic solvent while adjusting the resin content at 40% by weight or more, and adding a specific amount of lactam and a specific amount of an alcohol and/or an oxime separately before, during or after the above-mentioned reaction so as to adjust the reduced viscosity of the resin to 0.10 to 0.27.
Inventors
- 👤 Hiroshi Nishizawa
- 👤 Yoshiyuki Mukoyama
- 👤 Shozo Kasai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:05
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/14; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/306
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
101 words
A process for producing a polyamide-imide resin which comprises reacting an aromatic diisocyanate with a tricarboxylic acid anhydride in approximately equimolar amounts in the presence of a basic solvent which is inert to the aromatic diisocyanate while adjusting the resin content at 40% by weight or more and adding a lactam containing an active hydrogen on the amide nitrogen in an amount of 0.1 to 1.0 mole per mole of the aromatic diisocyanate to the resulting reaction system before, during or after the reaction to mask terminal isocyanate groups and to make the reduced viscosity of the resin 0.10 to 0.27.
Claim 2
Dependent Claim
101 words
A process for producing a polyamide-imide resin which comprises reacting an aromatic diisocyanate with a tricarboxylic acid anhydride in approximately equimolar amounts in the presence of a basic solvent which is inert to the aromatic diisocyanate while adjusting the resin content at 40% by weight or more and adding a lactam containing an active hydrogen on the amide nitrogen in an amount of 0.1 to 1.0 mole per mole of the aromatic diisocyanate to the resulting reaction system before, during or after the reaction to mask terminal isocyanate groups and to make the reduced viscosity of the resin 0.10 to 0.27.
Claim 3
Dependent Claim
67 words
A process according to claim 1, wherein after the lactam is added to the reaction system before, during or after the reaction of the aromatic diisocyanate and the tricarboxylic acid anhydride to mask terminal isocyanate groups mainly, another masking agent selected from the group consisting of an alcohol, an oxime and a mixture thereof is added to the reaction system to mask terminal acid anhydride groups mainly.
Claim 4
Dependent Claim
16 words
A process according to claim 1, wherein the aromatic diisocyanate is 4,4'-diphenylmethane diisocyanate or tolylene diisocyanate.
Claim 5
Dependent Claim
14 words
A process according to claim 1, wherein the tricarboxylic acid anhydride is trimellitic anhydride.
Claim 6
Dependent Claim
14 words
A process according to claim 1, wherein the basic solvent is N-methylpyrrolidone or dimethylformamide.
Claim 7
Dependent Claim
11 words
A process according to claim 1, wherein the lactam is ε-caprolactam.
Claim 8
Dependent Claim
17 words
A process according to claim 2, wherein the alcohol is methanol and the oxime is 2-butanone oxime.
Claim 9
Dependent Claim
58 words
A process according to claim 2, wherein the lactam is added to the reaction system before or during the reaction of the aromatic diisocyanate and the tricarboxylic acid anhydride, and the alcohol and/or the oxime is added to the reaction system after the reaction of the aromatic diisocyanate and the tricarboxylic acid anhydride to mask terminal functional groups.
Claim 10
Dependent Claim
21 words
A process according to claim 8, wherein the lactam is ε-caprolactam, the alcohol is methanol and the oxime is 2-butanone oxime.
Claim 11
Dependent Claim
68 words
A process according to claim 1, wherein another masking agent selected from the group consisting of an alcohol, and oxime and a mixture thereof in amounts of 0.25 mole or less per mole of the aromatic diisocyanate is added to the reaction system before or during the reaction of the aromatic diisocyanate and the tricarboxylic acid anhydride, followed by the addition of the lactam to the reaction system.
Claim 12
Dependent Claim
21 words
A process according to claim 1, wherein the basic solvent is selected from the group consisting of N-methylpyrrolidone, dimethylformamide, and dimethylacetamide.
Claim 13
Dependent Claim
20 words
A process according to claim 1, wherein a masking agent consisting of said lactam is added to the reaction system.
Claim 14
Dependent Claim
48 words
A process according to claim 1, wherein a masking agent consisting of said lactam and an alcohol having one active hydrogen in the molecule is added to the reaction system, said alcohol being added in an amount of 0.01 to 0.5 mole per mole of the aromatic diisocyanate.
Claim 15
Dependent Claim
51 words
A process according to claim 1, wherein a masking agent selected from the group consisting of said lactam and an oxime having one active hydrogen in the molecule is added to the reaction system, said oxime being in an amount of 0.01 to 0.5 mole per mole of the aromatic diisocyanate.
Claim 16
Dependent Claim
66 words
A process according to claim 1, wherein a masking agent consisting of said lactam and a mixture of an alcohol having one active hydrogen in the molecular and an oxime having one active hydrogen in the molecule is added to the reaction system, said mixture of the oxime and the alcohol being in an amount of 0.01 to 0.5 mole per mole of the aromatic diisocyanate.
Claim 17
Dependent Claim
27 words
A process according to claim 1, wherein said polyamide-imide resin consists essentially of the reaction product of said aromatic diisocyanate, said tricarboxylic acid anhydride and said lactam.
Claim 18
Dependent Claim
35 words
A process according to claim 2, said polyamide-imide resin consists essentially of the reaction product of said aromatic diisocyanate, said tricarboxylic acid anhydride, said lactam and at least one of said alcohol and said oxime.
Claim 19
Dependent Claim
26 words
A process according to claim 11, wherein said aromatic diisocyanate is 4,4'-diphenylmethane or tolylene diisocyanate, the acid anhydride is trimellitic anhydride and the lactam is ε-caprolactam.
References Cited (Backward Citations)
US4076694A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |