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US4935180A
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Formation of melt-spun acrylic fibers possessing a highly uniform internal structure which are particularly suited for thermal conversion to quality carbon fibers
Assignee: BP Corp North America Inc
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Filing: 1988-08-25
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Granted: 1990-06-19
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Expires: 2008-08-25
Abstract
Abstract An acrylic multifilamentary material possessing an internal structure which is particularly suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of acetonitrile and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. This fibrous material which is capable of readily undergoing drawing is passed through a heat treatment zone wherein the evolution of residual acetonitrile and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production. One accordingly is provided a reliable route to form a fibrous acrylic precursor for carbon fiber production without the necessity to employ the solution-spinning routes commonly utilized in the prior art for precursor formation. One can now eliminate the utilization and handling of large amounts of solvent as has heretofore been necessary when forming an acrylic carbon fiber precursor. Also, acrylic fiber precursors possessing a wide variety of cross-sectional configurations and a highly uniform internal structure now are made possible which can be thermally converted into carbon fibers of a similar cross-sectional configuration which are substantially void free when examined in cross section at a magnification of 2,000X.
Inventors
- 👤 Gene P. Daumit
- 👤 Yoon S. Ko
- 👤 Christopher R. Slater
- 👤 Jozef G. Venner
- 👤 Chi C. Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:13
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; D01D; D01D5/00; D01D5/08; D01F6/00; D01F6/02; D01F6/18
Claims Analysis
Total Claims: 81
Claim 1
Independent Claim
292 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers comprising: (a) forming at an elevated temperature a substantially homogeneous melt consisting essentially of (i) an acrylic polymer containing at least 85 weight percent of recurring acrylonitrile units, (ii) approximately 11 to 25 percent by weight of acetonitrile based upon said polymer, and (iii) approximately 12 to 28 percent by weight of water based upon said polymer, (b) extruding said substantially homogeneous melt while at a temperature within the range of 140° to 190° C. which exceeds the hydration and melting temperature by at least 15° C. through an extrusion orifice containing a plurality of openings into a filament-forming zone provided with a substantially non-reactive gaseous atmosphere provided at a temperature within the range of approximately 25° to 250° C. while under a longitudinal tension wherein substantial portions of said acetonitrile and water are evolved and an acrylic multifilamentary material is formed, (c) drawing said substantially homogeneous melt and acrylic multifilamentary material subsequent to passage through said extrusion orifice at a draw ratio of approximately 0.6 to 6.0:1, (d) passing said resulting acrylic multifilamentary material following steps (b) and (c) in the direction of its length through a heat treatment zone provided at a temperature of approximately 90° to 200° C. while at a relatively constant length wherein the evolution of substantially all of the residual acetonitrile and water present therein takes place, and (e) drawing said acrylic multifilamentary material resulting from step (d) while at an elevated temperature at a draw ratio of at least 3:1 to form an acrylic multifilamentary material having a mean single filament denier of approximately 0.3 to 5.0.
Claim 2
Dependent Claim
292 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers comprising: (a) forming at an elevated temperature a substantially homogeneous melt consisting essentially of (i) an acrylic polymer containing at least 85 weight percent of recurring acrylonitrile units, (ii) approximately 11 to 25 percent by weight of acetonitrile based upon said polymer, and (iii) approximately 12 to 28 percent by weight of water based upon said polymer, (b) extruding said substantially homogeneous melt while at a temperature within the range of 140° to 190° C. which exceeds the hydration and melting temperature by at least 15° C. through an extrusion orifice containing a plurality of openings into a filament-forming zone provided with a substantially non-reactive gaseous atmosphere provided at a temperature within the range of approximately 25° to 250° C. while under a longitudinal tension wherein substantial portions of said acetonitrile and water are evolved and an acrylic multifilamentary material is formed, (c) drawing said substantially homogeneous melt and acrylic multifilamentary material subsequent to passage through said extrusion orifice at a draw ratio of approximately 0.6 to 6.0:1, (d) passing said resulting acrylic multifilamentary material following steps (b) and (c) in the direction of its length through a heat treatment zone provided at a temperature of approximately 90° to 200° C. while at a relatively constant length wherein the evolution of substantially all of the residual acetonitrile and water present therein takes place, and (e) drawing said acrylic multifilamentary material resulting from step (d) while at an elevated temperature at a draw ratio of at least 3:1 to form an acrylic multifilamentary material having a mean single filament denier of approximately 0.3 to 5.0.
Claim 3
Dependent Claim
46 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic polymer contains at least 91 weight percent of recurring acrylonitrile units.
Claim 4
Dependent Claim
46 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic polymer contains 91 to 98 weight percent of recurring acrylonitrile units.
Claim 5
Dependent Claim
76 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic polymer includes recurring units derived from a member selected from the group consisting of methyl acrylate, methyl methacrylate, and mixtures thereof, and recurring units derived from a member selected from the group consisting of methacrylic acid, itaconic acid, and mixtures thereof.
Claim 6
Dependent Claim
105 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 4 wherein said acrylic polymer comprises 93 to 98 weight percent of recurring acrylonitrile units, approximately 1.7 to 6.5 weight percent of recurring units derived from a member selected from the group consisting of methyl acrylate, methyl methacrylate, and mixtures thereof, and approximately 0.3 to 2.0 weight percent of recurring units derived from a member selected from the group consisting of methacrylic acid, itaconic acid, and mixtures thereof.
Claim 7
Dependent Claim
60 words
An improved process for the formation of an acrylic multifilament material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially homogeneous melt of step (a) contains approximately 72 to 80 percent by weight of said acrylic polymer based upon the total weight of the composition.
Claim 8
Dependent Claim
59 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acetonitrile is provided in said substantially homogeneous melt in step (a) in a concentration of approximately 14 to 21 percent by weight of said polymer.
Claim 9
Dependent Claim
59 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said water is provided in said substantially homogeneous melt in step (a) in a concentration of approximately 15 to 23 percent by weight of said polymer.
Claim 10
Dependent Claim
55 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially homogeneous melt of step (a) additionally contains a minor concentration of a lubricant and a minor concentration of a surfactant.
Claim 11
Dependent Claim
44 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 9 wherein said lubricant is sodium stearate and said surfactant is sorbitan monolaurate.
Claim 12
Dependent Claim
52 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially homogeneous melt is at a temperature of approximately 155° to 185° C. when extruded in step (b).
Claim 13
Dependent Claim
58 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially homogeneous melt is at a temperature which exceeds the hydration and melting temperature by at least 20° C. when extruded in step (b).
Claim 14
Dependent Claim
58 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially homogeneous melt is at a temperature which exceeds the hydration and melting temperature by 20° to 40° C. when extruded in step (b).
Claim 15
Dependent Claim
57 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein during step (b) said extrusion orifice contains a plurality of substantially circular openings having diameters within the range of approximately 40 to 65 microns.
Claim 16
Dependent Claim
48 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein during step (b) said extrusion orifice contains a plurality of substantially uniform substantially non-circular openings.
Claim 17
Dependent Claim
62 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially non-reactive gaseous atmosphere of said filament-forming zone of step (b) is selected from the group consisting of air, steam, carbon dioxide, nitrogen, and mixtures of the foregoing.
Claim 18
Dependent Claim
56 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially non-reactive gaseous atmosphere of said filament-forming zone of step (b) is provided at a pressure of approximately 0 to 100 psig.
Claim 19
Dependent Claim
57 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially non-reactive gaseous atmosphere of said filament-forming zone of step (b) is provided at a superatmospheric pressure of approximately 10 to 50 psig.
Claim 20
Dependent Claim
58 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said substantially non-reactive gaseous atmosphere of said filament-forming zone of step (b) is provided at a temperature within the range of 90° to 200° C.
Claim 21
Dependent Claim
51 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic multifilamentary material is drawn at a draw ratio of approximately 0.8 to 5.0:1 during step (c).
Claim 22
Dependent Claim
44 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said drawing step (c) is carried out in said filament-forming zone.
Claim 23
Dependent Claim
69 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein a portion of said drawing of step (c) is carried out in said filament-forming zone simultaneously with said filament formation, and a portion of said drawing is carried out in at least one adjacent drawing zone.
Claim 24
Dependent Claim
53 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein at the conclusion of step (c) said acrylic multifilamentary material possesses a denier per filament of approximately 3 to 40.
Claim 25
Dependent Claim
61 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic multifilamentary material at the conclusion of step (c) comprises filaments having a substantially circular cross section and a denier to filament of approximately 3 to 12.
Claim 26
Dependent Claim
63 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said acrylic multifilamentary material at the conclusion of step (c) comprises filaments having a predetermined substantially uniform non-circular cross section and a denier per filament of approximately 6 to 40.
Claim 27
Dependent Claim
51 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said heat treatment zone of step (d) is provided at a temperature of approximately 110° to 175° C.
Claim 28
Dependent Claim
52 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein during step (d) said acrylic multifilamentary material comes in contact with the surface of at least one heated roller.
Claim 29
Dependent Claim
51 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein during step (d) said acrylic multifilamentary material comes in contact with the drums of a suction drum drier.
Claim 30
Dependent Claim
61 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein at the conclusion of step (d) said acrylic multifilamentary material contains less than 2.0 percent by weight of acetonitrile and water based upon the weight of said polymer.
Claim 31
Dependent Claim
60 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to carbon fibers according to claim 1 wherein at the conclusion of step (d) said acrylic multifilamentary material contains less than 1.0 percent by weight of acetonitrile and water based upon the weight of said polymer.
Claim 32
Dependent Claim
52 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein during step (e) said resulting acrylic multifilamentary material is drawn at a draw ratio of approximately 4 to 10:1.
Claim 33
Dependent Claim
47 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said drawing of step (e) is carried out in an atmosphere which contains steam.
Claim 34
Dependent Claim
52 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein said drawing of step (e) is carried out in steam at a pressure of approximately 10 to 30 psig.
Claim 35
Dependent Claim
65 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to high strength carbon fibers according to claim 32 wherein prior to said drawing of step (e) said acrylic multifilamentary material is conditioned by passage while at a substantially constant length through an atmosphere containing hot water, steam, or mixtures thereof.
Claim 36
Dependent Claim
58 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 33 wherein prior to drawing in step (e) said acrylic multifilamentary material is conditioned by passage while at a substantially constant length through an atmosphere containing steam.
Claim 37
Dependent Claim
62 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having substantially uniform substantially circular cross sections and a denier per filament of approximately 0.3 to 1.5.
Claim 38
Dependent Claim
62 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having substantially uniform substantially circular cross sections and a denier per filament of approximately 0.5 to 1.2.
Claim 39
Dependent Claim
69 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a predetermined substantially uniform non-circular cross section wherein the closest filament surface from all internal locations is less than 8 microns in distance.
Claim 40
Dependent Claim
51 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having substantially uniform crescent-shaped cross sections.
Claim 41
Dependent Claim
56 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having substantially uniform multi-lobed cross sections of at least three lobes.
Claim 42
Dependent Claim
57 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material possesses a mean single filament tensile strength of at least 5.0 grams per denier.
Claim 43
Dependent Claim
57 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein following said drawing of step (e) said acrylic multifilamentary material possesses a mean single filament tensile strength of at least 6.0 grams per denier.
Claim 44
Dependent Claim
66 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein the product of step (e) upon thermal stabilization and carbonization is capable of yielding carbon fibers having a substantially circular cross section and an impregnated strand tensile strength of at least 400,000 psi.
Claim 45
Dependent Claim
66 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein the product of step (e) following thermal stabilization and carbonization is capable of yielding carbon fibers having a substantially circular cross section and an impregnated strand tensile strength of at least 450,000 psi.
Claim 46
Dependent Claim
68 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 1 wherein the product of step (e) upon thermal stabilization and carbonization is capable of yielding carbon fibers having a predetermined substantially uniform non-circular cross section and an impregnated strand tensile strength of at least 300,000 psi.
Claim 47
Dependent Claim
331 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers comprising: (a) forming at an elevated temperature a substantially homogeneous melt consisting essentially of (i) an acrylic polymer containing at least 91 weight percent of recurring acrylonitrile units, (ii) approximately 14 to 21 percent by weight of acetonitrile based upon said polymer, and (iii) approximately 15 to 23 percent by weight of water based upon said polymer, with the proviso that the said acrylic polymer is present in a concentration of approximately 72 to 80 percent by weight based upon the total weight of the melt, (b) extruding said substantially homogeneous melt while at a temperature within the range of 155° to 185° C. which exceeds the hydration and melting temperature by at least 20° C. through an extrusion orifice containing a plurality of openings into a filament-forming zone provided with a substantially non-reactive gaseous atmosphere at a pressure of approximately 10 to 50 psig provided at a temperature within the range of approximately 90° to 200° C. while under a longitudinal tension wherein substantial portions of said acetonitrile and water are evolved and an acrylic multifilamentary material is formed, (c) drawing said substantially homogeneous melt and acrylic multifilamentary material subsequent to passage through said extrusion orifice at a draw ratio of approximately 0.8 to 5.0:1, (d) passing said resulting acrylic multifilamentary material following steps (b) and (c) in the direction of its length through a heat treatment zone provided at a temperature of approximately 110° to 175° C. while at a relatively constant length wherein the evolution of substantially all of the residual acetonitrile and water present therein takes place, and (e) drawing said acrylic multifilamentary material resulting from step (d) while at an elevated temperature at a draw ratio of approximately 4 to 10:1 to form an acrylic multifilamentary material having a mean single filament denier of approximately 0.3 to 5.0.
Claim 48
Dependent Claim
331 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers comprising: (a) forming at an elevated temperature a substantially homogeneous melt consisting essentially of (i) an acrylic polymer containing at least 91 weight percent of recurring acrylonitrile units, (ii) approximately 14 to 21 percent by weight of acetonitrile based upon said polymer, and (iii) approximately 15 to 23 percent by weight of water based upon said polymer, with the proviso that the said acrylic polymer is present in a concentration of approximately 72 to 80 percent by weight based upon the total weight of the melt, (b) extruding said substantially homogeneous melt while at a temperature within the range of 155° to 185° C. which exceeds the hydration and melting temperature by at least 20° C. through an extrusion orifice containing a plurality of openings into a filament-forming zone provided with a substantially non-reactive gaseous atmosphere at a pressure of approximately 10 to 50 psig provided at a temperature within the range of approximately 90° to 200° C. while under a longitudinal tension wherein substantial portions of said acetonitrile and water are evolved and an acrylic multifilamentary material is formed, (c) drawing said substantially homogeneous melt and acrylic multifilamentary material subsequent to passage through said extrusion orifice at a draw ratio of approximately 0.8 to 5.0:1, (d) passing said resulting acrylic multifilamentary material following steps (b) and (c) in the direction of its length through a heat treatment zone provided at a temperature of approximately 110° to 175° C. while at a relatively constant length wherein the evolution of substantially all of the residual acetonitrile and water present therein takes place, and (e) drawing said acrylic multifilamentary material resulting from step (d) while at an elevated temperature at a draw ratio of approximately 4 to 10:1 to form an acrylic multifilamentary material having a mean single filament denier of approximately 0.3 to 5.0.
Claim 49
Dependent Claim
46 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said acrylic polymer contains 91 to 98 weight percent of recurring acrylonitrile units.
Claim 50
Dependent Claim
76 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said acrylic polymer includes recurring units derived from a member selected from the group consisting of methyl acrylate, methyl methacrylate, and mixtures thereof, and recurring units derived from a member selected from the group consisting of methacrylic acid, itaconic acid, and mixtures thereof.
Claim 51
Dependent Claim
99 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 48 wherein said acrylic polymer comprises 93 to 98 weight percent of recurring acrylonitrile units, approximately 1.7 to 6.5 weight percent of recurring units derived from a member selected from the group consisting of methyl acrylate, methyl methacrylate, and mixtures thereof, and approximately 0.3 to 2.0 weight percent of recurring units derived from a member selected from the group consisting of methacrylic acid, itaconic acid, and mixtures thereof.
Claim 52
Dependent Claim
64 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein the substantially homogeneous melt formed in step (a) comprises said acrylic polymer in a concentration of approximately 74 to 80 percent by weight based upon the total weight of the melt.
Claim 53
Dependent Claim
55 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said substantially homogeneous melt of step (a) additionally contains a minor concentration of a lubricant and a minor concentration of a surfactant
Claim 54
Dependent Claim
44 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 51 wherein said lubricant is sodium stearate and said surfactant is sorbitan monolaurate.
Claim 55
Dependent Claim
59 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal, conversion to quality carbon fibers according to claim 46 wherein said substantially homogeneous melt is at a temperature which exceeds the hydration and melting temperature by approximately 20° to 40° C. when extruded in step (b).
Claim 56
Dependent Claim
57 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein during step (b) said extrusion orifice contains a plurality of substantially circular openings having diameters within the range of approximately 40 to 65 microns.
Claim 57
Dependent Claim
48 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein during step (b) said extrusion orifice contains a plurality of substantially uniform substantially non-circular openings.
Claim 58
Dependent Claim
58 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said substantially non-reactive gaseous atmosphere of step (b) is selected from the group consisting of air, steam, carbon dioxide, nitrogen, and mixtures of the foregoing.
Claim 59
Dependent Claim
44 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said drawing step (c) is carried out in said filament-forming zone.
Claim 60
Dependent Claim
69 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein a portion of said drawing of step (c) is carried out in said filament-forming zone simultaneously with said filament formation, and a portion of said drawing is carried out in at least one adjacent drawing zone
Claim 61
Dependent Claim
53 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein at the conclusion of step (c) said acrylic multifilamentary material possesses a denier per filament of approximately 3 to 40.
Claim 62
Dependent Claim
61 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said acrylic multifilamentary material at the conclusion of step (c) comprises filaments having a substantially circular cross section and a denier per filament of approximately 3 to 12.
Claim 63
Dependent Claim
63 words
An improved process for the formation of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said acrylic multifilamentary material at the conclusion of step (c) comprises filaments having a predetermined substantially uniform non-circular cross section and a denier per filament of approximately 6 to 40.
Claim 64
Dependent Claim
52 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein during step (d) said acrylic multifilamentary material comes in contact with the surface of at least one heated roller.
Claim 65
Dependent Claim
51 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein during step (d) said acrylic multifilamentary material comes in contact with the drums of a suction drum drier.
Claim 66
Dependent Claim
61 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein at the conclusion of step (d) said acrylic multifilamentary material contains less than 2.0 percent by weight of acetonitrile and water based upon the weight of said polymer.
Claim 67
Dependent Claim
61 words
An improved process for the production or an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein at the conclusion of step (d) said acrylic multifilamentary material contains less than 1.0 percent by weight of acetonitrile and water based upon the weight of said polymer.
Claim 68
Dependent Claim
47 words
An improved process for the production or an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said drawing of step (e) is carried out in an atmosphere which contains steam.
Claim 69
Dependent Claim
52 words
An improved process for the production or an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein said drawing of step (e) is carried out in steam at a pressure of approximately 10 to 30 psig.
Claim 70
Dependent Claim
64 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 66 wherein prior to said drawing of step (e) said acrylic multifilamentary material is conditioned by passage while at a substantially constant length through an atmosphere containing hot water, steam, or mixtures thereof.
Claim 71
Dependent Claim
59 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly well suited for thermal conversion to quality carbon fibers according to claim 67 wherein prior to drawing in step (e) said acrylic multifilamentary material is conditioned by passage while at a substantially constant length through an atmosphere containing steam.
Claim 72
Dependent Claim
61 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a substantially circular cross section and a denier per filament of approximately 0.3 to 1.5.
Claim 73
Dependent Claim
61 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal, conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a substantially circular cross section and a denier per filament of approximately 0.5 to 1.2.
Claim 74
Dependent Claim
68 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal, conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a predetermined substantially uniform non-circular cross section wherein the closest surface from all internal locations is less than 6 microns in distance.
Claim 75
Dependent Claim
50 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein following said drawing step (e) said acrylic multifilamentary material comprises filaments having substantially uniform crescent-shaped cross sections.
Claim 76
Dependent Claim
55 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary& material comprises filaments having substantially uniform multi-lobed cross-sections of at least three lobes.
Claim 77
Dependent Claim
59 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a mean single filament tensile strength of at least 5.0 grams per denier.
Claim 78
Dependent Claim
59 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal, conversion to quality carbon fibers according to claim 46 wherein following said drawing of step (e) said acrylic multifilamentary material comprises filaments having a mean single filament tensile strength of at least 6.0 grams per denier.
Claim 79
Dependent Claim
66 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein the product of step (e) upon thermal stabilization and carbonization is capable of yielding carbon fibers having a substantially circular cross section and an impregnated strand tensile strength of at least 400,000 psi.
Claim 80
Dependent Claim
66 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal conversion to quality carbon fibers according to claim 46 wherein the product of step (e) upon thermal stabilization and carbonization is capable of yielding carbon fibers having a substantially circular cross section and an impregnated strand tensile strength of at least 450,000 psi.
Claim 81
Dependent Claim
68 words
An improved process for the production of an acrylic multifilamentary material possessing a highly uniform internal structure which is particularly suited for thermal, conversion to quality carbon fibers according to claim 46 wherein the product of step (e) upon thermal stabilization and carbonization is capable of yielding carbon fibers having a predetermined substantially uniform non-circular cross section and an impregnated strand tensile strength of at least 300,000 psi.
References Cited (Backward Citations)
US2585444A
Cited
US3634575A
Cited
US3655857A
Cited
US3669919A
Cited
US3838562A
Cited
US3940405A
Cited
US3984601A
Cited
US3896204A
Cited
US4094948A
Cited
US4163770A
Cited
US3873508A
Cited
US4108818A
Cited
US4205039A
Cited
US4524105A
Cited
US4301107A
Cited
US4219523A
Cited
US4220617A
Cited
US4220616A
Cited
US4318680A
Cited
US4238442A
Cited
US4394339A
Cited
US4278415A
Cited
US4276011A
Cited
US4261945A
Cited
US4317790A
Cited
US4316714A
Cited
US4346053A
Cited
US4283365A
Cited
US4254076A
Cited
US4418176A
Cited
US4301104A
Cited
US4303607A
Cited
US4461739A
Cited
JPS6262909A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |