US4460526A
Expired / Lapsed
US
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Process for producing aromatic polyimide hollow filaments
Assignee: Ube Corp
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Filing: 1982-04-02
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Granted: 1984-07-17
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Expires: 2002-04-02
Abstract
Abstract Aromatic polyimide hollow fibers having an enhanced mechanical strength are produced by a process comprising the steps of: preparing a spinning dope solution of at least one aromatic polyimide having 90 molar % or more of a recurring unit of the formula (I). <IMAGE> wherein R is a divalent aromatic radical, in a phenolic solvent; converting the dope solution into at least one filamentary stream thereof; and introducing the filamentary dope solution stream into a coagulating liquid having a coagulating rate coefficient of 1.5 microns/sec for the dope solution, to provide rigid hollow filaments.
Inventors
- 👤 Hiroshi Makino
- 👤 Yoshihiro Kusuki
- 👤 Takashi Harada
- 👤 Hiroshi Shimazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:54
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/08; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; D; D01; D01D; D01D5/00; D01D5/24
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
142 words
A process for producing aromatic polyimide hollow filaments comprising the steps of: (1) preparing a spinning dope solution of a polymer material consisting of at least one aromatic polyimide having at least 90 molar % of a recurring unit of the formula (I): ##STR7## wherein R represents a divalent aromatic radical, in a solvent comprising, as a main component thereof, at least one phenolic compound; (2) extruding said spinning dope solution through at least one spinning hole to form at least one hollow filamentary stream thereof; and (3) introducing said hollow filamentary streams of said spinning dope solution into a coagulating liquid which is compatible with said solvent, but not compatible with said polymer material, and which exhibits a coefficient of coagulating rate of 1.5 microns/second or more for said spinning dope solution, to provide coagulated hollow filaments of said polymer material.
Claim 2
Dependent Claim
142 words
A process for producing aromatic polyimide hollow filaments comprising the steps of: (1) preparing a spinning dope solution of a polymer material consisting of at least one aromatic polyimide having at least 90 molar % of a recurring unit of the formula (I): ##STR7## wherein R represents a divalent aromatic radical, in a solvent comprising, as a main component thereof, at least one phenolic compound; (2) extruding said spinning dope solution through at least one spinning hole to form at least one hollow filamentary stream thereof; and (3) introducing said hollow filamentary streams of said spinning dope solution into a coagulating liquid which is compatible with said solvent, but not compatible with said polymer material, and which exhibits a coefficient of coagulating rate of 1.5 microns/second or more for said spinning dope solution, to provide coagulated hollow filaments of said polymer material.
Claim 3
Dependent Claim
33 words
The process as claimed in claim 1, wherein the divalent aromatic group represented by R in the formula (I) is a residue of an aromatic diamine from which two amino groups are excluded.
Claim 4
Dependent Claim
54 words
The process as claimed in claim 1, wherein said aromatic polyimide has a logarithmic viscosity of from 0.3 to 7.0, determined at a concentration of 0.5 g per 100 ml of a mixture solvent of 4 parts by volume of P-chlorophenol and 1 part by volume of O-chlorophenol at a temperature of 30° C.
Claim 5
Dependent Claim
62 words
The process as claimed in claim 1, wherein said aromatic polyimide is a polymerization-and-imidization product of a tetracarboxylic acid component comprising at least 90 molar % of at least one biphenyl tetracarboxylic acid or its anhydride, salt or ester with a diamine component comprising at least one aromatic diamine of the formula (II): H.sub.2 N--R--NH.sub.2 (II) wherein R is as defined above.
Claim 6
Dependent Claim
26 words
The process as claimed in claim 4, wherein said biphenyl tetracarboxylic acid is selected from the group consisting of 3,3',4,4'-biphenyl tetracarboxylic anhydride and 2,3,3',4'-biphenyl tetracarboxylic anhydride.
Claim 7
Dependent Claim
58 words
The process as claimed in claim 4, wherein said tetracarboxilic acid component contains 10 molar % or less of at least one member selected from the group consisting of pyromellitic acid, 3,3,',4,4'-benzophenone tetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, bis (3,4-dicarboxyphenyl) thioether, butane tetracarboxylic acid, and anhydrides, salts and esters of the above-mentioned compounds.
Claim 8
Dependent Claim
106 words
The process as claimed in claim 4, wherein said aromatic diamine is selected from the group consisting of those of the formulae (III) and (IV): ##STR8## wherein R 1 and R 2 respectively represent, independently from each other, a member selected from the group consisting of a hydrogen atom, lower alkyl radicals having 1 to 3 carbon atoms and lower alkoxyl radicals having 1 to 3 carbon atoms; A represents a divalent linking member selected from the class consisting of --O--, --S--, --C--, --SO 2 --, --SO--, --CH 2 -- and --C(CH 3 ) 2 --, and m represents an integer of from 1 to 4.
Claim 9
Dependent Claim
33 words
The process as claimed in claim 1, wherein said phenolic compound has a melting point of 100° C. or less and a boiling point of about 300° C. or less under atmospheric pressure.
Claim 10
Dependent Claim
28 words
The process as claimed in claim 1, wherein said phenolic compound is selected from the group consisting of phenol, alkyl-substituted monohydric phenol compounds and halogenated monohydric phenol compounds.
Claim 11
Dependent Claim
27 words
The process as claimed in claim 9, wherein said alkyl-substituted monohydric phenol compound is selected from the group consisting of O-, m-and P-cresols, 3,5-xylenol, carvacrol and thymol.
Claim 12
Dependent Claim
55 words
The process as claimed in claim 9, wherein said monohydric halogenated phenol compound is selected from the group consisting of those of the formula (VII): ##STR9## wherein R 3 represents a member selected from the group consisting of a hydrogen atom and alkyl radicals having 1 to 3 carbon atoms, and X represents halogen atoms.
Claim 13
Dependent Claim
22 words
The process as claimed in claim 1, wherein said spinning dope solution contains 5 to 30% by weight of said polymer material.
Claim 14
Dependent Claim
30 words
The process as claimed in claim 1, wherein said spinning dope solution has a rotation viscosity of at least 500 centiposes at a temperature of from 0° to 150° C.
Claim 15
Dependent Claim
24 words
The process as claimed in claim 1, wherein the coagulating rate coefficient of said coagulating liquid is 2.0 microns/second for said spinning dope solution.
Claim 16
Dependent Claim
73 words
The process as claimed in claim 1, wherein said coagulating liquid comprises at least one member selected from the groups consisting of lower aliphatic alcohols having 1 to 5 carbon atoms, lower aliphatic ketones having 3 to 5 carbon atoms, tetrahydrofuran, dioxane, ethyleneglycol monomethylether, lower alkylene glycols, diamethylacetamide, dimethylformamide, dimethylsulfoxide, diethylsulfoxide, lower aliphatic carboxylic acids having 1 to 4 carbon atoms, and mixtures of at least one of the above-mentioned compounds with water.
Claim 17
Dependent Claim
18 words
The process as claimed in claim 1, wherein said coagulation is carried out in two or more stages.
Claim 18
Dependent Claim
23 words
The process as claimed in claim 1, wherein the resultant hollow filaments are drawn at a temperature of from 20° to 600° C.
Claim 19
Dependent Claim
23 words
The process as claimed in claim 1, wherein the resultant hollow filaments are dranw at a draw ratio of from 1.1 to 5.0.
Claim 20
Dependent Claim
18 words
The process as claimed in claim 17, wherein said drawing procedure is carried out in a dry atmosphere.
Claim 21
Dependent Claim
18 words
The process as claimed in claim 17, wherein said drawing procedure is carried out in a wet medium.
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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) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |