US3859187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic process for the surface modification of high modulus carbon fibers
Assignee: Celanese Corp
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Filing: 1972-09-25
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Granted: 1975-01-07
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Expires: 1992-09-25
Abstract
Abstract An improved electrolytic process is provided for modifying the surface characteristics of an electrically conductive high modulus graphitic carbonaceous fibrous material (i.e., exhibiting a mean single filament Young''s modulus of at least about 60 million psi) and to thereby facilitate enhanced adhesion between the fibrous material and a resinous matrix material. The electrolytic process is carried out upon immersion of the fibrous material in an aqueous electrolytic solution of sodium hypochlorite (as defined) provided at a moderate temperature for a relatively brief residence time (i.e., about 2 to 10 minutes) while subjected to a relatively low current density (i.e., about 2.5 to 12 milliamps per square centimeter of surface area of fibrous material), and thereafter washing the same. Composite articles of enhanced interlaminar shear strength may be formed by incorporating the fibers modified in accordance with the present process in a resinous matrix material.
Inventors
- 👤 Melvin L Druin
- 👤 Andrew H Diedwardo
- 👤 James A Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:32
CPC Classifications
D; D06; D06M; D06M14/00; D06M14/36; D01; D01F; D01F11/00; D01F11/10; D01F11/12; D01F11/121; D01F11/16; D01F9/00; D01F9/08; D01F9/12; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/2929; Y10T428/2931; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
109 words
AN IMPROVED ELECTROLYTIC PROCESS FOR ENHANCING THE ABILITY OF AN ELECTRICALLY CONDUCTIVE CARBONACEOUS FIBROUS MATERIAL CONTAINING AT LEAST ABOUT 90 PERCENT CARBON BY WEIGHT AND EXHIBITING A MEAN SINGLE FILAMENT YOUNG''S MODULUS OF AT LEAST ABOUT 60 MILLION PSI AND A PREDOMINANTLY GRAPHITIC X-RAY DIFFRACTION PATTERN TO BOND TO A RESINOUS MATRIX MATERIAL COMPRISING: A. IMMERSING SAID FIBROUS MATERIAL IN AN AQUEOUS ELECTROLYTIC SOLUTION OF SODIUM HYPOCHLORITE HAVING A PH OF ABOUT 8 TO 12 AND AN ACTIVE CHLORINE CONCENTRATION OF ABOUT 1 TO 7 PERCENT BY WEIGHT, B. PROVIDING A CATHODE IN CONTACT WITH SAID AQUEOUS ELECTROLYTIC SOLUTION AND IN A SPACED RELATIONSHIP TO SAID IMMERSED FIBROUS MATERIAL,
Claim 2
Dependent Claim
109 words
AN IMPROVED ELECTROLYTIC PROCESS FOR ENHANCING THE ABILITY OF AN ELECTRICALLY CONDUCTIVE CARBONACEOUS FIBROUS MATERIAL CONTAINING AT LEAST ABOUT 90 PERCENT CARBON BY WEIGHT AND EXHIBITING A MEAN SINGLE FILAMENT YOUNG''S MODULUS OF AT LEAST ABOUT 60 MILLION PSI AND A PREDOMINANTLY GRAPHITIC X-RAY DIFFRACTION PATTERN TO BOND TO A RESINOUS MATRIX MATERIAL COMPRISING: A. IMMERSING SAID FIBROUS MATERIAL IN AN AQUEOUS ELECTROLYTIC SOLUTION OF SODIUM HYPOCHLORITE HAVING A PH OF ABOUT 8 TO 12 AND AN ACTIVE CHLORINE CONCENTRATION OF ABOUT 1 TO 7 PERCENT BY WEIGHT, B. PROVIDING A CATHODE IN CONTACT WITH SAID AQUEOUS ELECTROLYTIC SOLUTION AND IN A SPACED RELATIONSHIP TO SAID IMMERSED FIBROUS MATERIAL,
Claim 3
Dependent Claim
38 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 1 wherein said carbonaceous fibrous material contains at least about 95 percent carbon by weight.
Claim 4
Dependent Claim
43 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 1 wherein said carbonaceous fibrous material exhibits a mean single filament Young''s modulus of about 60 to 90 million psi.
Claim 5
Dependent Claim
43 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 1 wherein said carbonaceous fibrous material is continuously passed through said aqueous electrolytic solution in the direction of its length.
Claim 6
Dependent Claim
45 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 1 wherein said aqueous electrolytic solution of sodium hypochlorite has an active chlorine concentration of about 3 to 7 percent by weight.
Claim 7
Dependent Claim
52 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 1 wherein said aqueous solution of sodium hypochlorite has a pH of about 10.5 to 11.5 and an active chlorine concentration of about 5.025 to 5.4 percent by weight.
Claim 8
Dependent Claim
38 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material according to claim 1 wherein said aqueous electrolytic solution is provided at a temperature of about 20* to 35*C.
Claim 9
Dependent Claim
39 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material according to claim 1 wherein said electrical current is applied to said fibrous material for about 2 to 6 minutes.
Claim 10
Dependent Claim
50 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix according to claim 1 wherein said washing is conducted by initially contacting said resulting carbonaceous fibrous material with a solution of a dilute acid, and by suBsequently rinsing the same with water.
Claim 11
Dependent Claim
191 words
An improved process for enhancing the ability of a carbonaceous fibrous material containing at least about 95 percent carbon by weight and exhibiting a mean single filament Young''s modulus of about 60 to 90 million psi and a predominantly graphitic x-ray diffraction pattern to bond to a resinous matrix material comprising: a. immersing said fibrous material in an aqueous electrolytic solution of sodium hypochlorite provided at about 20* to 35*C. having a pH of about 10.5 to 11.5 and an active chlorine concentration of about 5.025 to 5.4 percent by weight, b. providing a cathode in contact with said aqueous electrolytic solution and in a spaced relationship to said immersed fibrous material, c. applying electrical current to said fibrous material while immersed in said aqueous electrolytic solution of sodium hypochlorite at a current density of about 4 to 12 milliamps per square centimeter of surface area of said immersed fibrous material for a residence time of about 2 to 6 minutes with said fibrous material serving as an anode, d. washing the resulting carbonaceous fibrous material to remove residual aqueous electrolytic solution adhering to the same, and e. drying the same.
Claim 12
Dependent Claim
191 words
An improved process for enhancing the ability of a carbonaceous fibrous material containing at least about 95 percent carbon by weight and exhibiting a mean single filament Young''s modulus of about 60 to 90 million psi and a predominantly graphitic x-ray diffraction pattern to bond to a resinous matrix material comprising: a. immersing said fibrous material in an aqueous electrolytic solution of sodium hypochlorite provided at about 20* to 35*C. having a pH of about 10.5 to 11.5 and an active chlorine concentration of about 5.025 to 5.4 percent by weight, b. providing a cathode in contact with said aqueous electrolytic solution and in a spaced relationship to said immersed fibrous material, c. applying electrical current to said fibrous material while immersed in said aqueous electrolytic solution of sodium hypochlorite at a current density of about 4 to 12 milliamps per square centimeter of surface area of said immersed fibrous material for a residence time of about 2 to 6 minutes with said fibrous material serving as an anode, d. washing the resulting carbonaceous fibrous material to remove residual aqueous electrolytic solution adhering to the same, and e. drying the same.
Claim 13
Dependent Claim
43 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 10 wherein said carbonaceous fibrous material is continuously passed through said aqueous electrolytic solution in the direction of its length.
Claim 14
Dependent Claim
37 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 10 wherein said electrolytic aqueous solution of sodium hypochlorite is provided at about 25*C.
Claim 15
Dependent Claim
52 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 10 wherein said washing is conducted by initially contacting said resulting carbonaceous fibrous material with a solution of a dilute acid, and by sebsequently rinsing the same with water.
Claim 16
Dependent Claim
184 words
An improved process for enhancing the ability of a carbonaceous fibrous material containing at least about 95 percent carbon by weight and exhibiting a mean single filament Young''s modulus of about 70 to 90 million psi and a predominantly graphitic x-ray diffraction pattern to bond to a resinous matrix material comprising: a. immersing said fibrous material in an aqueous solution of sodium hypochlorite provided at about 25*C. having a pH of about 11 and an active chlorine concentration of about 5.025 to 5.4 percent by weight, b. providing a cathode in contact with said aqueous electrolytic solution and in a spaced relationship to said immersed fibrous material, c. applying electrical current to said fibrous material while immersed in said aqueous electrolytic solution of sodium hypochlorite at a current density of about 4 milliamps per square centimeter of surface area of said immersed fibrous material for a residence time of about 5 to 6 minutes with said fibrous material serving as an anode, d. washing the resulting carbonaceous fibrous material to remove residual aqueous electrolytic solution adhering to the same, and e. drying the same.
Claim 17
Dependent Claim
184 words
An improved process for enhancing the ability of a carbonaceous fibrous material containing at least about 95 percent carbon by weight and exhibiting a mean single filament Young''s modulus of about 70 to 90 million psi and a predominantly graphitic x-ray diffraction pattern to bond to a resinous matrix material comprising: a. immersing said fibrous material in an aqueous solution of sodium hypochlorite provided at about 25*C. having a pH of about 11 and an active chlorine concentration of about 5.025 to 5.4 percent by weight, b. providing a cathode in contact with said aqueous electrolytic solution and in a spaced relationship to said immersed fibrous material, c. applying electrical current to said fibrous material while immersed in said aqueous electrolytic solution of sodium hypochlorite at a current density of about 4 milliamps per square centimeter of surface area of said immersed fibrous material for a residence time of about 5 to 6 minutes with said fibrous material serving as an anode, d. washing the resulting carbonaceous fibrous material to remove residual aqueous electrolytic solution adhering to the same, and e. drying the same.
Claim 18
Dependent Claim
43 words
An improved process for enhancing the ability of a carbonaceous fibrous material to bond to a resinous matrix material in accordance with claim 14 wherein said carbonaceous fibrous material is continuously passed through said aqueous electrolytic solution in the direction of its length.
Claim 19
Dependent Claim
33 words
A composite article exhibiting enhanced interlaminar shear strength comprising a resinous matrix material having incorporated therein a carbonaceous fibrous material having its surface characteristics modified in accordance wiTh the process of claim 1.
References Cited (Backward Citations)
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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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |