US3961888A
Expired / Lapsed
US
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Acrylic fiber conversion utilizing a stabilization treatment conducted initially in an essentially inert atmosphere
Assignee: Celanese Corp
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Filing: 1968-09-18
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Granted: 1976-06-08
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Expires: 1988-09-18
Abstract
Abstract A process is provided for the stabilization of a fibrous material composed of an acrylic polymer, e.g. an acrylonitrile homopolymer or a closely related copolymer. The fibrous material is subjected to a multiple stage stabilization treatment in which the initial stage is conducted in an essentially inert atmosphere, and a subsequent stage in an atmosphere containing an appreciable quantity of oxygen. The initial treatment which is conducted in a relatively inert atmosphere is believed to result in an improved cyclized molecular structure without encountering excessive chain cleavage, and is followed by an oxygen cross-linking reaction. The stabilized product exhibits improved physical properties. Carbonized or carbonized and graphitized fibrous materials may be formed upon heating the stabilized product in an inert atmosphere.
Inventors
- 👤 John P. Riggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:26
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; D01F9/225; D06; D06M; D06M11/00; D06M11/32; D06M11/34
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
105 words
A process for the stabilization of an acrylic fibrous material comprising heating a fibrous material consisting primarily of recurring acrylonitrile units in an essentially inert atmosphere at a temperature of about 200°C. to 270°C. until a cyclized product is formed in the absence of appreciable oxygen cross-linking which retains its original fibrous configuration essentially intact, and subsequently heating said cyclized product in an oxygen-containing atmosphere at a temperature of about 180°C. to 325°C. until an oxygen cross-linked stabilized fibrous product capable of undergoing carbonization is formed which retains its original fibrous configuration essentially intact and which is non-burning when subjected to an ordinary match flame.
Claim 2
Dependent Claim
105 words
A process for the stabilization of an acrylic fibrous material comprising heating a fibrous material consisting primarily of recurring acrylonitrile units in an essentially inert atmosphere at a temperature of about 200°C. to 270°C. until a cyclized product is formed in the absence of appreciable oxygen cross-linking which retains its original fibrous configuration essentially intact, and subsequently heating said cyclized product in an oxygen-containing atmosphere at a temperature of about 180°C. to 325°C. until an oxygen cross-linked stabilized fibrous product capable of undergoing carbonization is formed which retains its original fibrous configuration essentially intact and which is non-burning when subjected to an ordinary match flame.
Claim 3
Dependent Claim
16 words
A process according to claim 1 in which said acrylic fibrous material is an acrylonitrile homopolymer.
Claim 4
Dependent Claim
44 words
A process according to claim 1 in which said acrylic fibrous material is an acrylonitrile copolymer which contains at least about 95 mol per cent of acrylonitrile units and up to about 5 mol per cent of one or more monovinyl units copolymerized therewith.
Claim 5
Dependent Claim
28 words
A process according to claim 1 in which said acrylic fibrous material possesses a single filament tenacity of at least about 5 grams per denier prior to stabilization.
Claim 6
Dependent Claim
24 words
A process according to claim 1 in which said inert atmosphere is selected from the group consisting of essentially pure nitrogen, helium, and argon.
Claim 7
Dependent Claim
14 words
A process according to claim 1 in which said oxygen containing atmosphere is air.
Claim 8
Dependent Claim
15 words
A process according to claim 1 in which said acrylic fibrous material is a yarn.
Claim 9
Dependent Claim
55 words
A process according to claim 1 in which said acrylic fibrous material is heated in said essentially inert atmosphere at a temperature of about 200°C. to 270°C. for about 70 hours to 30 minutes, and in said oxygen containing atmosphere at a temperature of about 180°C. to 325°C. for about 40 hours to 15 minutes.
Claim 10
Dependent Claim
110 words
A process for the stabilization of a continuous length of a fibrous material consisting of an acrylonitrile homopolymer comprising continuously passing said material through an essentially inert atmosphere maintained at a temperature of about 200°C. to 270°C. until a cyclized product is formed in the absence of appreciable oxygen cross-linking which retains its original fibrous configuration essentially intact, and subsequently continuously passing said cyclized product through an oxygen-containing atmosphere maintained at a temperature of about 180°C. to 325°C. until an oxygen cross-linked stabilized fibrous product capable of undergoing carbonization is formed which retains its original fibrous configuration essentially intact and which is non-burning when subjected to an ordinary match flame.
Claim 11
Dependent Claim
110 words
A process for the stabilization of a continuous length of a fibrous material consisting of an acrylonitrile homopolymer comprising continuously passing said material through an essentially inert atmosphere maintained at a temperature of about 200°C. to 270°C. until a cyclized product is formed in the absence of appreciable oxygen cross-linking which retains its original fibrous configuration essentially intact, and subsequently continuously passing said cyclized product through an oxygen-containing atmosphere maintained at a temperature of about 180°C. to 325°C. until an oxygen cross-linked stabilized fibrous product capable of undergoing carbonization is formed which retains its original fibrous configuration essentially intact and which is non-burning when subjected to an ordinary match flame.
Claim 12
Dependent Claim
20 words
A process according to claim 9 in which said continuous length of an acrylonitrile homopolymer is a continuous filament yarn.
Claim 13
Dependent Claim
24 words
A process according to claim 9 in which said inert atmosphere is selected from the group consisting of essentially pure nitrogen, helium, and argon.
Claim 14
Dependent Claim
14 words
A process according to claim 9 in which said oxygen containing atmosphere is air.
Claim 15
Dependent Claim
33 words
A process according to claim 9 wherein said continuous length of acrylonitrile homopolymer fibrous material is continuously passed through said inert atmosphere and said oxygen containing atmosphere in the direction of its length.
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) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |