US4705618A
Expired / Lapsed
US
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Process for the preparation of an intermediate pitch for manufacturing carbon products
Assignee: Maruzen Petrochemical Co Ltd
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Filing: 1986-04-08
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Granted: 1987-11-10
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Expires: 2006-04-08
Abstract
Abstract Until now, it has not yet been succeeded to prepare high performance carbon fibers having satisfactory strength from heavy oils of coal or petroleum origin. We now succeeded to prepare an excellent intermediate pitch which allows the preparation of high performance carbon fibers having tensile strength of higher than 300 Kg/mm 2 and Young's modulus of 50 ton/mm 2 . The intermediate pitch can be obtained by heating a heavy oil of coal or petroleum origin in a tubular heater under a specific conditions, and then flash distilling the heater effluent in a flash distillation column under a specific condition so as to remove lighter fractions and recovering heavy fraction from the column bottom as the intermediate pitch. The process for the preparation of the intermediate pitch is simple and economical and allows continuous production without fluctuation of quality of the intermediate pitch. The intermediate pitch is also suitable for the production of higher density carbon products.
Inventors
- 👤 Masatoshi Tsuchitani
- 👤 Ryoichi Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:06
CPC Classifications
C; C10; C10C; C10C1/00; C10C1/04; C10C1/08; C10C1/16; C10C1/19; C10C3/00; C10C3/002; C10C3/06; D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
194 words
A process for the continuous preparation of an almost optically isotropic and substantially homogeneous intermediate pitch with a benzene isoluble fraction content of more than 50 wt %, a quinoline insoluble fraction content of less than 30 wt % and a beta-resins content of more than 40 wt % for manufacturing a mesophase pitch for preparing carbon fibers which comprises heating a heavy oil having a quinoline insoluble fraction content of less than 5 wt % selected from the group consisting of coal tars, coal tar pitches, tar by-products from naptha cracking, tar by-products from gas oil cracking and decant oils, in a tubular heater under a pressure of 4 to 50 Kg/cm 2 .G at a temperature of 400° to 520° C. with a residence time of 30 to 1000 sec; transferring the heater effluent to a flash distillation column and conducting flash distillation under a pressure of 0.3 to 1.5 Kg/cm 2 .A at a temperature of 430° to 500° C. so as to separate lighter fractions as the overhead of said column from a heavy fraction and recovering said heavy fraction from the bottom of said column as said intermediate pitch.
Claim 2
Dependent Claim
194 words
A process for the continuous preparation of an almost optically isotropic and substantially homogeneous intermediate pitch with a benzene isoluble fraction content of more than 50 wt %, a quinoline insoluble fraction content of less than 30 wt % and a beta-resins content of more than 40 wt % for manufacturing a mesophase pitch for preparing carbon fibers which comprises heating a heavy oil having a quinoline insoluble fraction content of less than 5 wt % selected from the group consisting of coal tars, coal tar pitches, tar by-products from naptha cracking, tar by-products from gas oil cracking and decant oils, in a tubular heater under a pressure of 4 to 50 Kg/cm 2 .G at a temperature of 400° to 520° C. with a residence time of 30 to 1000 sec; transferring the heater effluent to a flash distillation column and conducting flash distillation under a pressure of 0.3 to 1.5 Kg/cm 2 .A at a temperature of 430° to 500° C. so as to separate lighter fractions as the overhead of said column from a heavy fraction and recovering said heavy fraction from the bottom of said column as said intermediate pitch.
Claim 3
Dependent Claim
38 words
The process of claim 1, wherein the conditions for heating in said tubular heater are a pressure of 6 to 30 Kg/cm 2 .G, a temperature of 430° to 500° C. and a residence time of 50-500 sec.
Claim 4
Dependent Claim
38 words
The process of claim 2, wherein the conditions for heating in said tubular heater are a pressure of 8 to 25 Kg/cm 2 .G, a temperature of 450° to 500° C. and a residence time of 80-300 sec.
Claim 5
Dependent Claim
280 words
A process for the preparation of a hydrogenated pitch for manufacturing a mesophase pitch for preparing carbon fibers which comprises heating a heavy oil having quinoline insoluble fraction content of less than 5 wt % selected from the group consisting of coal tars, coal tar pitches, tar by-products from naphtha cracking, tar by-products from gas oil cracking and decant oils in a tubular heater under a pressure of 4 to 50 Kg/cm 2 .G at a temperature of 400° to 520° C. with a residence time of 30 to 1000 seconds; transferring the heater effluent to a flash distillation column and conducting a flash distillation under a pressure of 0.3 to 1.5 Kg/cm 2 .A at a temperature of 430° to 500° C. so as to separate lighter fractions as the overhead of said column from a heavy fraction; recovering said heavy fraction from the bottom of said column as an almost isotropic and substantially homogeneous intermediate pitch having a benzene insoluble fraction content of more than 50 wt %, a quinoline insoluble fraction content of less than 30 wt %, and a beta-resins content of more than 40 wt %, hydrogenating said intermediate pitch by using at least one compound selected from the group consisting of tetrahydroquinoline, hydrogenated naphthalene oil, hydrogenated anthracene oil, hydrogenated creosote oil and hydrogenated absorbing oil as a hydrogenating agent and a solvent, in an amount of 1 to 3 parts per 1 part of said intermediate pitch at a temperature of 380° to 480° C., under a presure of 20 to 50 Kg/cm 2 .G for 10 minutes to 5 hours and removing said hydrogenating agent and lighter fractions formed during the hydrogenation reaction.
Claim 6
Dependent Claim
280 words
A process for the preparation of a hydrogenated pitch for manufacturing a mesophase pitch for preparing carbon fibers which comprises heating a heavy oil having quinoline insoluble fraction content of less than 5 wt % selected from the group consisting of coal tars, coal tar pitches, tar by-products from naphtha cracking, tar by-products from gas oil cracking and decant oils in a tubular heater under a pressure of 4 to 50 Kg/cm 2 .G at a temperature of 400° to 520° C. with a residence time of 30 to 1000 seconds; transferring the heater effluent to a flash distillation column and conducting a flash distillation under a pressure of 0.3 to 1.5 Kg/cm 2 .A at a temperature of 430° to 500° C. so as to separate lighter fractions as the overhead of said column from a heavy fraction; recovering said heavy fraction from the bottom of said column as an almost isotropic and substantially homogeneous intermediate pitch having a benzene insoluble fraction content of more than 50 wt %, a quinoline insoluble fraction content of less than 30 wt %, and a beta-resins content of more than 40 wt %, hydrogenating said intermediate pitch by using at least one compound selected from the group consisting of tetrahydroquinoline, hydrogenated naphthalene oil, hydrogenated anthracene oil, hydrogenated creosote oil and hydrogenated absorbing oil as a hydrogenating agent and a solvent, in an amount of 1 to 3 parts per 1 part of said intermediate pitch at a temperature of 380° to 480° C., under a presure of 20 to 50 Kg/cm 2 .G for 10 minutes to 5 hours and removing said hydrogenating agent and lighter fractions formed during the hydrogenation reaction.
Claim 7
Dependent Claim
39 words
The process of claim 4, wherein the conditions for heating in said tubular heater are a pressure of 6 to 30 Kg/cm 2 .G, a temperature of 430° to 500° C. and residence time of 50 to 500 seconds.
Claim 8
Dependent Claim
39 words
The process of claim 4, wherein the conditions for heating in said tubular heater are a pressure of 8 to 25 Kg/cm 2 .G, a temperature of 450° to 500° C. and residence time of 80 to 300 seconds.
Claim 9
Dependent Claim
25 words
The process of claim 4, wherein the hydrogenation is conducted at a temperature of 400° to 450° C. for from 20 minutes to 3 hours.
References Cited (Backward Citations)
US2850436A
Cited
US3140248A
Cited
DE1645736A1
Cited
FR2169896A1
Cited
US4177133A
Cited
US4049538A
Cited
FR2303062A1
Cited
JPS54160427A
Cited
FR2396793A1
Cited
US4472265A
Cited
EP0056338A1
Cited
US4522701A
Cited
EP0087749A1
Cited
US4528087A
Cited
JPS58214531A
Cited
US4518482A
Cited
US4589975A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |