Patent US4704196A successfully refreshed from Google Patents.
US4704196A
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Process for surface treatment of carbon fiber
Assignee: Tonen General Sekiyu KK
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Filing: 1986-11-17
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Granted: 1987-11-03
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Expires: 2006-11-17
Abstract
Abstract A process for the surface treatment of carbon fiber tows each consisting of a multiplicity of filaments, comprises treating the tows by electrolytic oxidation, using each tow as a positive electrode and applying an electric current in the form of pulses. The pulse spacing is such that the electric supply and non-supply durations are 0.02-20 sec. each, preferably 0.1-5 seconds each. The pulse shape is rectangular, triangular, or sine waves. The applied voltage is 3-15 V and the current density 0.2-1000 A/m 2 , preferably 1-100 A/m 2 , more preferably 5-20 A/m 2 . The electrolyte is an aqueous solution of an oxidizing agent, strong acid or base, neutral salt, or weak acid or base.
Inventors
- 👤 Makoto Saito
- 👤 Hiroshi Inoue
- 👤 Noboru Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:30
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/34; D; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/122; D01F11/16; Y; Y10; Y10S; Y10S204/00; Y10S204/08; Y10S204/09
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
42 words
A process for the surface treatment of carbon fiber tows each consisting of a multiplicity of filaments, which comprises treating the tows by electrolytic oxidation, using each tow as a positive electrode and applying an electric current in the form of pulses.
Claim 2
Dependent Claim
42 words
A process for the surface treatment of carbon fiber tows each consisting of a multiplicity of filaments, which comprises treating the tows by electrolytic oxidation, using each tow as a positive electrode and applying an electric current in the form of pulses.
Claim 3
Dependent Claim
33 words
A process according to claim 1 wherein the pulse spacing of the pulsed electric supply is set so that the electric supply and no-electric supply durations range from 0.02 to 20 seconds each.
Claim 4
Dependent Claim
33 words
A process according to claim 1 wherein the pulse spacing of the pulsed electric supply is set so that the electric supply and no-electric supply durations range from 0.1 to 5 seconds each.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the the pulses for electric supply takes the shape of rectangular, triangular, or sine waves.
Claim 6
Dependent Claim
33 words
A process according to claim 1 wherein the applied voltage for the pulsed electric supply ranges from 3 to 15 V, with the current density of from 0.2 to 1000 A/m 2 .
Claim 7
Dependent Claim
18 words
A process according to claim 5 wherein the current density ranges form 1 to 100 A/m 2 .
Claim 8
Dependent Claim
18 words
A process according to claim 5, wherein the current density ranges from 5 to 20 A/m 2 .
Claim 9
Dependent Claim
75 words
A process according to any one of claims 1 through 7 wherein the electrolyte is an aqueous solution of an oxidizing agent or a strongly acidic solution of hypochlorite, concentrated sulfuric acid, concentrated sulfuric acid plus Cr 6+ ion, or permanganate; strongly basic solution as of sodium hydroxide; aqueous solution of a neutral salt of sulfate or nitrate; aqueous weakly acidic solution of a carboxylate or phosphate; or aqueous weakly basic solution of sodium carbonate.
Claim 10
Dependent Claim
25 words
A process according to any of claim 1 to 2 wherein the pulses for electric supply take the shape of rectangular, triangular or sine waves.
Claim 11
Dependent Claim
69 words
A process according to claim 9 wherein the electrolyte is an aqueous solution of an oxidizing agent of a strongly acidic solution of hydrochlorite, concentrated sulfuric acid, concentrated sulfuric acid plus Cr 6+ ion, or permanganate; strongly basic solution of sodium hydroxide; aqueous solution of a neutral salt as sulfate or nitrate; aqueous weakly acidic solution of a carboxylate or phosphate; or aqueous weakly basic solution of sodium carbonate.
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) | 1990-11-02 | 1991-05-04 | 1991-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-02 | 1995-05-04 | 1995-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-02 | 1999-05-04 | 1999-11-03 | $7700.00 | Window Closed / Lapsed |