Patent US4251594A successfully refreshed from Google Patents.
US4251594A
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US
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Process for preparing resin impregnated substrates for use in preparing electrical laminates
Assignee: Dow Chemical Co
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Filing: 1979-09-27
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Granted: 1981-02-17
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Expires: 1999-09-27
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 having an aliphatic halide content of at least about 500 ppm such as a diglycidyl ether of bisphenol A with a dihydric phenolic compound such as tetrabromo bisphenol A in the presence of an alkali metal hydroxide such as potassium hydroxide.
Inventors
- 👤 William Davis
- 👤 Ross C. Whiteside, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:36
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/02; C08G59/04; C08G59/06; C08G59/066; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/244; C08J5/249; H; H01; H01B; H01B3/00; H01B3/02; H01B3/08; H01B3/084; H01B3/18; H01B3/30; H01B3/40; C08J2363/00; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0326; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 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; (II) heating the resultant impregnated substrate to B-stage the resin and remove the solvent system; the improvement which comprises: (a) employing as the catalyst, Component (A-3), an alkali metal hydroxide and (b) employing as the glycidyl ether of a dihydric phenol, Component (A-1), one which has an aliphatic halide content of at least about 500 ppm.
Claim 2
Dependent Claim
176 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; (II) heating the resultant impregnated substrate to B-stage the resin and remove the solvent system; the improvement which comprises: (a) employing as the catalyst, Component (A-3), an alkali metal hydroxide and (b) employing as the glycidyl ether of a dihydric phenol, Component (A-1), one which has an aliphatic halide content of at least about 500 ppm.
Claim 3
Dependent Claim
84 words
The process of claim 1 wherein Component (A-1) has an EEW of from about 170 to about 200 and an aliphatic halide content of from about 1000 ppm to about 6000 ppm; 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 and the quantity of catalyst, Component (A-3), is that which provides from about 0.05 to about 1.0 hydroxyl equivalent per equivalent of aliphatic halide contained in Component (A-1).
Claim 4
Dependent Claim
70 words
The process of claim 2 wherein Component (A-1) has an EEW of from about 180 to about 195; 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, and the quantity of catalyst, Component (A-3), is that which provides from about 0.10 to about 0.80 hydroxyl equivalent per equivalent of aliphatic halide contained in Component (A-1).
Claim 5
Dependent Claim
54 words
The process of claim 3 wherein Component (A-1) is diglycidyl ether of bisphenol A, Component (A-2) is tetrabromo bisphenol A and Component (A-3) is potassium hydroxide or sodium hydroxide and is employed in a quantity which provides from about 0.20 to about 0.60 hydroxyl equivalent per equivalent of aliphatic halide contained in Component (A-1).
Claim 6
Dependent Claim
15 words
A resin impregnated substrate prepared by the process of claims 1, 2, 3 or 4.
Claim 7
Dependent Claim
12 words
An electrical laminate prepared from the resin impregnated substrate of claim 5.
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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) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |