Patent US4038254A successfully refreshed from Google Patents.
US4038254A
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Process for the manufacture of wire insulation varnish resins suitable chiefly for application in the melted state
Assignee: Dynamit Nobel AG
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Filing: 1975-08-05
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Granted: 1977-07-26
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Expires: 1995-08-05
Abstract
Abstract A process for the manufacture of wire insulation varnish resins suitable for application from the melted state which comprises: 1. Contacting a lower alkyl ester of terephthalic acid with tris-(hydroxyethyl)-isocyanurate and ethylene glycol in the presence of a trans esterification catalyst in the presence of 0.3 to 1.5% of an alcoholate of titanium, vanadium or zirconium and effecting transesterification under transesterification conditions; 2. Contacting the transesterification product from step 1 with trimellitic acid anhydride under esterification conditions to further effect esterification, but prior to completion of such esterification; 3. Adding to the reaction mixture 4,4'-diaminodiphenyl methane in an amount such that the molar ratio of trimellitic acid derived from trimellitic acid anhydride to said 4,4'-diaminodiphenylmethane is 2 to 1; and 4. Polycondensing the reaction mixture until a resin is formed having a consistency at 140° to 160° C such that it can be applied to a wire substrate in melted form.
Inventors
- 👤 Gerhard Schade
- 👤 Peter Uckert
- 👤 Manfred Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:00
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/307; C; C08; C08G; C08G63/00; C08G63/68; C08G63/685; C08G63/6854; C08G73/00; C08G73/06; C08G73/10; C08G73/16; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
190 words
A process for the manufacture of wire insulation varnish resins suitable for application in the melted state which comprises: 1. contacting a lower alkyl ester of terephthalic acid with tris-(2-hydroxyethyl)-isocyanurate and ethylene glycol in the presence of 0.3 to 1.5%, with reference to the weight of the sum of all resin forming monomers, of an alcoholate of titanium, vanadium or zirconium and effecting transesterification under transesterification conditions until between 90 and 100% of the theoretically possible esterification is effected; 2. contacting the transesterification product of step 1 with trimellitic acid anhydride under esterification conditions to effect further esterification until between 40 and 55% of the theoretically possible esterification is effected; 3. prior to completion of the esterification of step 2 immediately adding to the reaction mixture 4,4'-diaminodiphenylmethane in an amount such that the molar ratio of the trimellitic acid derived from trimellitic acid anhydride to said 4,4'-diaminodiphenylmethane is between 2.1 and 1.9:1; and 4. polycondensing the reaction mixture until a resin is formed having a melt viscosity between 5,000 and 20,000 cP at 140° to 160° C. such that it can be applied to a wire substrate in melted form.
Claim 2
Dependent Claim
190 words
A process for the manufacture of wire insulation varnish resins suitable for application in the melted state which comprises: 1. contacting a lower alkyl ester of terephthalic acid with tris-(2-hydroxyethyl)-isocyanurate and ethylene glycol in the presence of 0.3 to 1.5%, with reference to the weight of the sum of all resin forming monomers, of an alcoholate of titanium, vanadium or zirconium and effecting transesterification under transesterification conditions until between 90 and 100% of the theoretically possible esterification is effected; 2. contacting the transesterification product of step 1 with trimellitic acid anhydride under esterification conditions to effect further esterification until between 40 and 55% of the theoretically possible esterification is effected; 3. prior to completion of the esterification of step 2 immediately adding to the reaction mixture 4,4'-diaminodiphenylmethane in an amount such that the molar ratio of the trimellitic acid derived from trimellitic acid anhydride to said 4,4'-diaminodiphenylmethane is between 2.1 and 1.9:1; and 4. polycondensing the reaction mixture until a resin is formed having a melt viscosity between 5,000 and 20,000 cP at 140° to 160° C. such that it can be applied to a wire substrate in melted form.
Claim 3
Dependent Claim
39 words
A process according to claim 1 wherein the alcoholate of titanium, vanadium or zirconium is an alcoholate of a C4 to C8 cyclic alcohol or a branched or unbranched alkanol having up to 5 carbon atoms in the chain.
Claim 4
Dependent Claim
12 words
A process according to claim 2 wherein the alcoholate is tetra-n-butyl titanate.
Claim 5
Dependent Claim
11 words
A process according to claim 2 wherein the alcoholate is tetraisopropyltitanate.
Claim 6
Dependent Claim
46 words
A process according to claim 2 wherein the reactants are present in the following mol ratio range: ______________________________________
Alkyl ester of terephthalic
1 to 4
acid
Tris-(hydroxyethyl)-isocyanurate
1 to 3
Ethylene glycol 3 to 15
Trimellitic acid anhydride
1 to 4
4,4'-diaminodiphenylmethane
0.5 to 3
______________________________________
Claim 7
Dependent Claim
46 words
A process according to claim 2 wherein the reactants are present in the following mol ratio range: ______________________________________
Alkyl ester of terephthalic acid
1 to 3
Tris-(hydroxyethyl)-isocyanurate
1 to 2
Ethylene glycol 5 to 12
Trimellitic acid anhydride
2 to 4
4,4'-diaminodiphenylmethane
1 to 2
______________________________________
Claim 8
Dependent Claim
31 words
A process according to claim 5 wherein the trimellitic acid anhydride is esterified until about 45 to 50% of the three carboxyl groups of the trimellitic acid are in esterified form.
Claim 9
Dependent Claim
84 words
A process according to claim 5 wherein: a. trimellitic acid anhydride is esterified in step 2 until between about 45 and 50% of the carboxylic acid groups on the corresponding trimellitic acid are esterified; b. the 4,4'-diaminodiphenylmethane in step 3 is added such that the molar ratio of said diamine to trimellitic acid derived from trimellitic acid anhydride is 1:2; and c. the polycondensation of step 4 is carried out at a temperature between 190° and 220° C. for between 1 and 5 hours.
Claim 10
Dependent Claim
14 words
A wire insulating varnish resin which is prepared by the process of claim 1.
Claim 11
Dependent Claim
51 words
A wire insulation varnish resin having a melt viscosity at 140° to 160° C. between 5,000 and 20,000 cP, said resin being the condensation product of a lower alkyl ester of terephthalic acid, tris-(2-hydroxyethyl)-isocyanurate, ethylene glycol, trimellitic acid anhydride and 4,4'-diaminodiphenylmethane, said varnish resin produced by the process of claim 1.
Claim 12
Dependent Claim
43 words
A process according to claim 1 wherein in step 3 all of the 4,4'-diaminodiphenylmethane is added to the reaction mixture within 3 to 15 minutes after the esterification of step 2 is effected to between 40 and 55% of the theoretically possible esterification.
Claim 13
Dependent Claim
27 words
A process according to claim 11 wherein the esterification of step 2 is effected until between 40 and 45% of the theoretically possible esterification has been effected.
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US3852246A
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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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |