US4168331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing resin impregnated substrates for use in preparing electrical laminates
Assignee: Dow Chemical Co
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Filing: 1978-08-03
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Granted: 1979-09-18
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Expires: 1998-08-03
Abstract
Abstract The preparation of substrates impregnated with epoxy resins and curing agents therefor is improved by employing as the epoxy resin one which has been prepared by reacting a low equivalent weight epoxy resin such as a diglycidyl ether of bisphenol A with a dihydric phenolic compound such as tetrabromo bisphenol A in the presence of a quaternary ammonium hydroxide such as tetramethyl ammonium hydroxide.
Inventors
- 👤 William Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:39
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/02; C08G59/04; C08G59/06; C08G59/066; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0326; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31525
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
In a process for preparing resin impregnated substrates for use in preparing electrical laminates which process comprises: (I) saturating said substrate with a resin forming mixture comprising; (A) an epoxy resin having an epoxide equivalent weight of from about 300 to about 600, which has been prepared by reacting (1) a glycidyl ether of a dihydric phenol having an average of more than one epoxide group per molecule and an epoxide equivalent weight (EEW) of from about 156 to about 400, with (2) a dihydric phenolic compound in the presence of (3) a catalyst for effecting the reaction between 1 and 2; (B) a curing agent for said epoxy resin and (C) a solvent system for Components A and B; and (II) heating the resultant impregnated substrate to B-stage the resin and remove the solvent system; the improvement which comprises employing as the catalyst a quaternary ammonium hydroxide.
Claim 2
Dependent Claim
148 words
In a process for preparing resin impregnated substrates for use in preparing electrical laminates which process comprises: (I) saturating said substrate with a resin forming mixture comprising; (A) an epoxy resin having an epoxide equivalent weight of from about 300 to about 600, which has been prepared by reacting (1) a glycidyl ether of a dihydric phenol having an average of more than one epoxide group per molecule and an epoxide equivalent weight (EEW) of from about 156 to about 400, with (2) a dihydric phenolic compound in the presence of (3) a catalyst for effecting the reaction between 1 and 2; (B) a curing agent for said epoxy resin and (C) a solvent system for Components A and B; and (II) heating the resultant impregnated substrate to B-stage the resin and remove the solvent system; the improvement which comprises employing as the catalyst a quaternary ammonium hydroxide.
Claim 3
Dependent Claim
43 words
The process of claim 1 wherein Component (A-1) has an EEW of from about 170 to about 200 and Components (A-1) and (A-2) are employed in quantities such that the phenolic hydroxyl to epoxide equivalent ratio is from about 0.2:1 to about 0.35:1.
Claim 4
Dependent Claim
42 words
The process of claim 2 wherein Component (A-1) has an EEW of from about 180 to about 195 and Components (A-1) and (A-2)are employed in quantities such that the phenolic hydroxyl to epoxide equivalent ratio is from about 0.24:1 to about 0.31:1.
Claim 5
Dependent Claim
60 words
The process of claim 3 wherein Component (A-1) is a diglycidyl ether of bisphenol A, Component (A-2) is tetrabromo bisphenol A and Component (A-3) is a quaternary ammonium hydroxide represented by the formula ##STR5## where is R 1 ,R 2 , R 3 , and R 4 are independently a hydrocarbon group having from 1 to about 10 carbon atoms.
Claim 6
Dependent Claim
12 words
The process of claim 4 wherein Component (A-3) is tetramethyl ammonium hydroxide.
Claim 7
Dependent Claim
13 words
The process of claim 4 wherein Component (A-3) is benzyl trimethyl ammonium hydroxide.
Claim 8
Dependent Claim
17 words
A resin impregnated substrate prepared by the process of claims 1, 2, 3, 4, 5 or 6.
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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) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |