US4468364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for extruding thermotropic liquid crystalline polymers
Assignee: Celanese Corp
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Filing: 1983-04-28
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Granted: 1984-08-28
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Expires: 2003-04-28
Abstract
Abstract Provided is a process for the extrusion of shaped articles which comprises extruding a thermotropic liquid crystal polymer through a short land or preferably no land die, and with subsequent drawdown of the extruded profile being such as to render a drawdown ratio of less than 4, and preferably about 1. Such extrusion of liquid crystal polymers in accordance with the present invention can consistently and reproducibly provide one with an article of high mechanical properties, and thus, particular advantage is found in employing the process to extrude an article of cross-sectional dimensions which must closely approximate those of the extrusion die without sacrificing high mechanical properties.
Inventors
- 👤 Yoshiaki Ide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:58
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/58; D01F6/62; B; B29; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/05; B29C48/07; B29C48/08; C; C08; C08G; C08G63/00; C08G63/02; C08G63/60; C08G63/605; C09; C09K; C09K19/00; C09K19/04; C09K19/38; C09K19/3804; C09K19/3809; D01D; D01D5/00; D01D5/08; B29K; B29K2105/00; B29K2105/0079
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
82 words
A process for extruding a polymer to form shaped articles comprising the steps of: (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die having a converging entry section and a land length such that the ratio of land length (L) to die orifice diameter (D) is less than 2, and (c) subjecting the extrudate to a drawdown using a haul-off or take-up device such that the drawdown ratio is less than 4.
Claim 2
Dependent Claim
82 words
A process for extruding a polymer to form shaped articles comprising the steps of: (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die having a converging entry section and a land length such that the ratio of land length (L) to die orifice diameter (D) is less than 2, and (c) subjecting the extrudate to a drawdown using a haul-off or take-up device such that the drawdown ratio is less than 4.
Claim 3
Dependent Claim
29 words
The process of claim 1, wherein the cross-sectional dimensions of the shaped article are substantially the same as that of the extrusion die orifice used in extruding the article.
Claim 4
Dependent Claim
19 words
The process of claim 1, wherein the drawdown ratio is in the range of from about 0.8 to 3.
Claim 5
Dependent Claim
19 words
The process of claim 1, wherein the drawdown ratio is in the range of from about 1 to 2.
Claim 6
Dependent Claim
11 words
The process of claim 1, wherein the ratio L/D is zero.
Claim 7
Dependent Claim
12 words
The process of claim 1, wherein the drawdown ratio is about 1.
Claim 8
Dependent Claim
15 words
The process of claim 1, wherein the liquid crystalline polymer is a wholly aromatic polyester.
Claim 9
Dependent Claim
26 words
The process of claim 1, wherein the liquid crystalline polymer includes not less than about 10 mole percent of recurring units which include a naphthalene moiety.
Claim 10
Dependent Claim
26 words
The process of claim 8, wherein the wholly aromatic polyester includes not less than about 10 mole percent of recurring units which include a naphthalene moiety.
Claim 11
Dependent Claim
18 words
The process of claim 9, wherein the naphthalene moiety is a 6-oxy-2-naphthoyl moiety, 2,6-dioxynaphthalene moiety or 2,6-dicarboxynaphthalene moiety.
Claim 12
Dependent Claim
13 words
The process of claim 10, wherein the naphthalene moiety is a 6-oxy-2-naphthoyl moiety.
Claim 13
Dependent Claim
30 words
The process of claim 1, wherein the thermotropic liquid crystal polymer is a wholly aromatic polyester, aromaticaliphatic polyester, wholly aromatic poly(ester-amide), aromaticaliphatic poly(ester-amide), aromatic polyazomethine, aromatic polyester-carbonate or mixture thereof.
Claim 14
Dependent Claim
15 words
The process of claim 1, wherein the thermotropic liquid crystal polymer is an aromatic poly(ester-amide).
Claim 15
Dependent Claim
82 words
The process for extruding a polymer to form shaped articles comprising the steps of: (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die having a converging entry section and substantially no land portion so that the ratio of land length (L) to die orifice diameter (D) is about zero, and (c) subjecting the extrudate to a drawdown such that the drawdown ratio is in the range of from about 1 to 2.
Claim 16
Dependent Claim
82 words
The process for extruding a polymer to form shaped articles comprising the steps of: (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die having a converging entry section and substantially no land portion so that the ratio of land length (L) to die orifice diameter (D) is about zero, and (c) subjecting the extrudate to a drawdown such that the drawdown ratio is in the range of from about 1 to 2.
Claim 17
Dependent Claim
17 words
The process of claim 14, wherein the liquid crystal polymer includes recurring units of a 6-oxy-2-naphthoyl moiety.
Claim 18
Dependent Claim
74 words
A process for extruding a polymer to form a shaped article having high mechanical properties and substantially the same cross-sectional dimensions as a die orifice used to extrude the article, said process comprising (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die which has substantially no land portion, and (c) subjecting the extrudate to a drawdown such that the drawdown ratio is about 1.
Claim 19
Dependent Claim
74 words
A process for extruding a polymer to form a shaped article having high mechanical properties and substantially the same cross-sectional dimensions as a die orifice used to extrude the article, said process comprising (a) providing thermotropic liquid crystal polymer in melt form, (b) extruding said liquid crystal polymer through an extrusion die which has substantially no land portion, and (c) subjecting the extrudate to a drawdown such that the drawdown ratio is about 1.
Claim 20
Dependent Claim
17 words
The process of claim 16, wherein the liquid crystal polymer includes recurring units of a 6-oxy-2-naphthoyl moiety.
References Cited (Backward Citations)
US4183895A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |