US3620996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyester-amide-imide insulating varnish and method of preparation
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1968-07-05
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Granted: 1971-11-16
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Expires: 1988-07-05
Abstract
Abstract An insulating varnish comprising essentially a polyester-amideimide obtained by condensating (1) a precondensation product prepared by reacting tricarboxylic acid anhydride and at least one isocyanate compound selected from the group consisting of a diisocyanate and polyisocyanate, solid precondensate having an amide linkage and an imide linkage in the molecular chain, and (2) at least one compound selected from the group consisting of terephthalic acid, isophthalic acid and lower dialkylesters thereof, di-ol and poly-ol, or (2) lower polymerization polyesters thereof.
Inventors
- 👤 Shigeru Matsumura
- 👤 Nobuyuki Asano
- 👤 Munetaka Kawaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:30
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/306; C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/34; C08G18/343; C08G18/345; C08G73/00; C08G73/06; C08G73/10; C08G73/16; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12556; Y10T428/12569
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
16 words
An insulating varnish claimed in claim 1, in which said tricarboxylic acid anhydride is trimellitic anhydride.
Claim 2
Dependent Claim
34 words
An insulating varnish claimed in claim 1, in which said diisocyanate is selected from the group consisting of 4, 4''-diphenylmethane diisocyanate, 4, 4''-diphenylether diisocyanate, 2, 4-tolylene diisocyanate, 2, 6''-tolylene diisocyanate, and polyphenylene methylene polyisocyanate.
Claim 3
Dependent Claim
14 words
An insulating varnish claimed in claim 1, in which the polyol is ethylene glycol.
Claim 4
Dependent Claim
26 words
An insulating varnish as claimed in claim 1, in which the polyol is selected from the group consisting of glycerin and tris -( Beta -hydroxyethyl) isocyanurate.
Claim 5
Dependent Claim
23 words
An insulating varnish claimed in claim 1, in which the condensation product contains from 1 to 80 percent amide linkages and imide linkages.
Claim 6
Dependent Claim
62 words
An insulating varnish as claimed in claim 1, in which said polyester-amide-imide condensation product is one obtained by the condensation polymerization reaction of (1) the precondensation product of claim 1 (2) least one compound selected from the group consisting of terephthalic acid, isophthalic acid and the lower dialkylesters thereof, and (3) a polyol of claim 1 in and inert and unreactive solvent.
Claim 7
Dependent Claim
71 words
An insulating varnish as claimed in claim 1, in which the polyester-amide-imide condensation product is one obtained by reacting in the molten state at least one compound of (2), said compound being selected from the group consisting of terephthalic acid, isophthalic acid and lower dialkylesters thereof, and a polyol of (3) and adding the precondensation product of (1) thereto after the reaction system becomes molten and before the product is gelated.
Claim 8
Dependent Claim
33 words
In an insulating wire comprising a coating on a wire substrate, said coating being baked on said substrate, the improvement which comprises the coating being the insulating varnish condensation product of claim 1.
Claim 9
Dependent Claim
60 words
A process for obtaining a condensation product of claim 1 comprising heating and reacting the tricarboxylic acid anhydride of claim 1 and at least one polyisocyanate compound of claim 1, and, when the reaction system is solidified, subsequently heating the mixture in an organic solvent which does not dissolve and swell the reaction product and is inert to the reaction.
Claim 10
Dependent Claim
17 words
A process as claimed in claim 10, in which the organic solvent is liquid during the reaction.
Claim 11
Dependent Claim
17 words
A process as claimed in claim 10, in which the organic solvent is gaseous during the reaction.
Claim 12
Dependent Claim
31 words
A process for obtaining the condensation product of claim 1 mixed with a liquid organic solvent which does not dissolve and swell the reaction product and is inert to the reaction.
Claim 13
Dependent Claim
95 words
An insulating varnish consisting essentially of a polyester-amide-imide condensation product obtained by condensing (1) a precondensation product prepared by reacting at a temperature of from 20* to 250* C. trimellitic anhydride, and 4, 4''-diphenyl-methylene diisocyanate, the ratio of the anhydride to the diisocyanate in the precondensate ranging from 1:1 to 1:0.05 (2) dimethyl terephthalate; and (2) a polyol selected from the group consisting of ethylene glycol and tris-( Beta -hydroxethyl)isocyanurate; the proportions of (2) and (3) above to (1) being such that the condensation product contains from 1 to 99 percent amide and imide linkages.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |