Patent US4408003A successfully refreshed from Google Patents.
US4408003A
Expired / Lapsed
US
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Varnishes for glasscloth laminates, methods of their production and laminates made therefrom
Assignee: Coal Industry Patents Ltd
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Filing: 1981-10-15
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Granted: 1983-10-04
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Expires: 2001-10-15
Abstract
Abstract The present invention relates to varnishes for use in the preparation of glasscloth laminates, methods of their production and laminates made therefrom. The varnish is made by dissolving 100 parts of a TFP resin having a number average molecular weight of about 1000 and an oxygen content of about 8% in 60 to 65 parts of butan-2-one or isopropanol. 8 to 12 parts of hexamine are dissolved in a minimum quantity of a solvent comprising water and IMS in a ratio of about 3:5. The two solutions are thoroughly mixed and filtered to produce the varnish. The varnish is used to prepare glasscloth laminates for use as printed circuit boards.
Inventors
- 👤 Joseph G. Robinson
- 👤 Sally A. Brain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:19
CPC Classifications
C; C09; C09D; C09D161/00; C09D161/04; C09D161/06; B; B32; B32B; B32B27/00; B32B27/04; C08; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/244; C08L; C08L61/00; C08L61/34; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0326; C08J2361/00; C08J2361/34; Y; Y10; Y10T; Y10T442/00; Y10T442/20; Y10T442/2926; Y10T442/2992
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
91 words
A varnish for the preparation of glasscloth laminates, comprising a mixture of: a solution of 100 parts of a TFP resin having a number average molecular weight of about 1000 and an oxygen content of about 8% dissolved in a solvent selected from the group consisting of C 4 to C 6 alkanones and C 3 or C 4 alkanols; and a solution of from 8 to 12 parts of hexamine dissolved in a minimum amount of a solvent comprising water and a lower alkanol in a ratio of about 3:5.
Claim 2
Dependent Claim
91 words
A varnish for the preparation of glasscloth laminates, comprising a mixture of: a solution of 100 parts of a TFP resin having a number average molecular weight of about 1000 and an oxygen content of about 8% dissolved in a solvent selected from the group consisting of C 4 to C 6 alkanones and C 3 or C 4 alkanols; and a solution of from 8 to 12 parts of hexamine dissolved in a minimum amount of a solvent comprising water and a lower alkanol in a ratio of about 3:5.
Claim 3
Dependent Claim
19 words
A varnish according to claim 1, wherein the TFP resin contains a small proportion of low molecular weight material.
Claim 4
Dependent Claim
12 words
A varnish according to claim 1, wherein the resin solvent is butan-2-one.
Claim 5
Dependent Claim
12 words
A varnish according to claim 1, wherein the resin solvent is iso-propanol.
Claim 6
Dependent Claim
16 words
A varnish according to claim 1, wherein the lower alkanol in the hexamine solvent is IMS.
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) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |