Patent US4412937A successfully refreshed from Google Patents.
US4412937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacture of activated carbon fiber
Assignee: Teijin Ltd
•
Filing: 1982-04-23
•
Granted: 1983-11-01
•
Expires: 2002-04-23
Abstract
Abstract A method for manufacturing activated carbon fibers is disclosed. The method is comprised of the steps of: (1) causing an acrylic fiber to contain therein a treating agent selected from the group consisting of phosphorus and boron compounds in a concentration of 0.01 to 0.3% by weight as phosphorus or boron based on the weight of the fiber; (2) preoxidizing the acrylic fiber in an oxidizing atmosphere at a temperature exceeding 200° C. and giving a core ratio of 18% until the amount of bonded oxygen becomes not less than 15% by weight based on the weight of the fiber thereby producing a preoxidized fiber; (3) adjusting the concentration of the treating agent in the preoxidized fiber to a level in the range of 0.04 to 1% by weight based on the thus obtained preoxidized fiber; and (4) thereafter activating the fiber at a temperature in the range of 900° to 1,300° C. The resulting fiber has improved high strength, high adsorbing ability and high processibility.
Inventors
- 👤 Shigeru Ikegami
- 👤 Minoru Hirai
- 👤 Kazuo Izumi
- 👤 Kenji Shimazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:00
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/382
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
174 words
A method for manufacturing acitivated carbon fiber, comprising the steps of: (1) causing an acrylic fiber to contain therein a treating agent, wherein the treating agent is selected from the group consisting of phosphorus and boron compounds in a concentration of 0.01 to 0.3% by weight as phosphorus, boron, or a mixture thereof, based on the weight of the fiber; (2) preoxidizing the acrylic fiber in an oxidizing atmosphere at a temperature exceeding 200° C. and giving a core ratio of not more than 18% until the amount of bonded oxygen becomes not less than 15% by weight based on the weight of fiber thereby producing a preoxidized fiber; (3) adjusting the concentration of the treating agent in the preoxidized fiber to a level in the range of 0.04 to 1% by weight based on the thus obtained preoxidized fiber; and (3) activating the fiber at a temperature in the range of 900° to 1,300° C., until said activated carbon fiber has a specific surface area of not less than 300 m 2 /g.
Claim 2
Independent Claim
174 words
A method for manufacturing acitivated carbon fiber, comprising the steps of: (1) causing an acrylic fiber to contain therein a treating agent, wherein the treating agent is selected from the group consisting of phosphorus and boron compounds in a concentration of 0.01 to 0.3% by weight as phosphorus, boron, or a mixture thereof, based on the weight of the fiber; (2) preoxidizing the acrylic fiber in an oxidizing atmosphere at a temperature exceeding 200° C. and giving a core ratio of not more than 18% until the amount of bonded oxygen becomes not less than 15% by weight based on the weight of fiber thereby producing a preoxidized fiber; (3) adjusting the concentration of the treating agent in the preoxidized fiber to a level in the range of 0.04 to 1% by weight based on the thus obtained preoxidized fiber; and (3) activating the fiber at a temperature in the range of 900° to 1,300° C., until said activated carbon fiber has a specific surface area of not less than 300 m 2 /g.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein said acrylic fiber is obtained from a homopolymer or a copolymer containing at least 60% by weight of acrylonitrile.
Claim 4
Dependent Claim
41 words
A method according to claim 1, wherein the phosphorus compound is selected from the group consisting of phosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorus acid, phosphinic acid, and salts of these acids, alkyl- and aryl-phosphonates, -phosphates and -phosphites of said acids.
Claim 5
Dependent Claim
51 words
A method according to claim 1, wherein the boron compound is at least one member selected from the group consisting of boric acid, metaboric acid, salts of said acids, and an organic boron compound represented by a general formula B(OR) 3 , wherein R represents an alkyl group or aryl group.
Claim 6
Independent Claim
21 words
A method according to any of claims 3 or 4, wherein the salts are ammonium salts, calcium salts or magnesium salts.
Claim 7
Dependent Claim
50 words
A method according to claim 1, wherein after the amount of bonded oxygen has become 5 to 8% by weight, a compound selected from the group consisting of phosphorus compounds, boron compounds and mixtures thereof is added to the fiber in an amount not exceeding 0.6% as phosphorus or boron.
Claim 8
Dependent Claim
59 words
A method according to claim 1, wherein the inclusion of the phosphorus or boron compound in the acrylic fiber is accomplished by causing a gel fiber which has been produced by solution spinning of an acrylic polymer and not yet subjected to drawing to be immersed in a solution or dispersion containing said phosphorus, boron compound, or mixtures thereof.
Claim 9
Dependent Claim
62 words
A method according to claim 1, wherein the inclusion of the phosphorus or boron compound in the acrylic fiber is accomplished by causing a fiber which has been produced by solution spinning of an acrylic polymer and subjected to drawing and not yet subjected to drying to be immersed in a solution or dispersion containing said phosphorus, boron compound or mixture thereof.
Claim 10
Dependent Claim
46 words
A method according to claim 1, wherein the inclusion of the phosphorus or boron compound in the acrylic fiber is accomplished after said acrylic fiber has been produced by immersing said acrylic fiber in a solution or dispersion containing said phosphorus, boron compound, or mixture thereof.
Claim 11
Independent Claim
37 words
A method according to any of claims 7, 8 or 9, wherein the fiber is caused to contain therein the phosphorus, boron compound or mixture thereof at a temperature in the range of 5° to 80° C.
Claim 12
Independent Claim
29 words
A method according to any of claims 7, 8 or 9, wherein the solution or dispersion containing the phosphorus, boron compound or mixtures thereof contains a surface active agent.
Claim 13
Dependent Claim
18 words
A method according to claim 1, wherein said oxidizing atmosphere comprises 0.2 to 35% by volume of oxygen.
Claim 14
Dependent Claim
35 words
A method according to claim 1, wherein preoxidation is carried out in an oxidizing atmosphere comprising 20 to 30% by volume of oxygen until the amount of bonded oxygen becomes 5 to 8% by weight.
Claim 15
Dependent Claim
35 words
A method according to claim 1, wherein preoxidation is carried out in an oxidizing atmosphere comprising 0.2 to 9% by volume of oxygen after the amount of bonded oxygen becomes 5 to 8% by weight.
Claim 16
Dependent Claim
37 words
A method according to claim 12, wherein preoxidation is carried out in an oxidizing atmosphere containing 95 to 25% by volume of carbon dioxide gas after the amount of bonded oxygen becomes 5 to 8% by weight.
Claim 17
Dependent Claim
21 words
A method according to claim 1, wherein said preoxidation is carried out at a temperature of from 200° to 400° C.
Claim 18
Dependent Claim
54 words
A method according to claim 1, wherein preoxidation is carried out at a temperature of from 225° to 350° C. until the amount of bonded oxygen becomes 5 to 8% by weight and then carrying out the preoxidation at a 10° to 50° C. higher temperature in the range of 250° to 400° C.
Claim 19
Dependent Claim
29 words
A method according to claim 15, wherein said oxidizing atmosphere consists of carbon dioxide and oxygen and preoxidation is carried out at a temperature of 200° to 700° C.
Claim 20
Dependent Claim
32 words
A method according to claim 1, wherein a tension is applied to the fiber during the preoxidation so that shrinkage of 70 to 90% of free shrinkage is given to the fiber.
Claim 21
Dependent Claim
25 words
A method according to claim 1, wherein activation is carried out in a furnace under an inner pressure of 0.002 to 2 kg/cm 2 .
Claim 22
Dependent Claim
50 words
A method according to claim 1, wherein the inclusion of the additive in the acrylic fiber is accomplished by causing a fiber which has been produced by solution spinning of an acrylic polymer and not yet subjected to drawing, to be sprayed with a solution or dispersion containing the additive.
Claim 23
Dependent Claim
54 words
A method according to claim 1, wherein the inclusion of the additive in the acrylic fiber is accomplished by causing a fiber which has been produced by solution spinning of an acrylic polymer and subjecting to drawing and not yet subjected to drying to be sprayed with a solution or dispersion containing the additive.
Claim 24
Dependent Claim
38 words
A method according to claim 1, wherein the inclusion of the additive in the acrylic fiber is accomplished after the acrylic fiber has been produced by spraying the acrylic fiber with a solution or dispersion containing the additive.
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) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |