US5248305A
Expired / Lapsed
US
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Extruded tubing and catheters having helical liquid crystal fibrils
Assignee: Cordis Corp
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Filing: 1992-08-24
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Granted: 1993-09-28
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Expires: 2012-08-24
Abstract
Abstract Extruded catheters and other flexible plastic tubing may be manufactured with improved rotational and/or longitudinal stiffness, compared with catheters made of more conventional plastics. A tubing of liquid crystal polymer plastic-containing material may be extruded through a tube extrusion die while rotating the inner and outer die walls to provide circumferential shear to the extruded tube. Thus the liquid crystal polymer is oriented in a helical manner to provide improved properties, including greater rotational stiffness.
Inventors
- 👤 Richard J. Zdrahala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:27
CPC Classifications
A; A61; A61M; A61M25/00; A61M25/0009; B; B29; B29C; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/0016; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/32; B29C48/33; B29C48/34; A61M25/0043; A61M25/005; A61M25/0053; B29C48/10; B29C48/335; B29K; B29K2105/00; B29K2105/0079; B29L; B29L2031/00; B29L2031/753; B29L2031/7542
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
145 words
In an extruded plastic catheter which defines a tubular catheter body, the improvement comprising, in combination: said catheter body being substantially defined by an extruded, tubular first layer, said first layer comprising, intermixed together, from 1 to 40 weight percent of a liquid crystal polymer and 60 to 99 weight percent of a different, softer structural plastic matrix which is not a liquid crystal polymer, said liquid crystal polymer defining a separate phase from said structural plastic matrix, said first layer exhibiting at least a degree of circumferential orientation to provide an increased amount of rotational stiffness to at least a section of said catheter body, said separate phase of the liquid crystal polymer defining generally helically extending fibrils dispersed throughout essentially the entire volume of said first layer, said fibrils being formed from liquid crystal polymer plastic droplets dispersed in said structural plastic matrix.
Claim 2
Dependent Claim
145 words
In an extruded plastic catheter which defines a tubular catheter body, the improvement comprising, in combination: said catheter body being substantially defined by an extruded, tubular first layer, said first layer comprising, intermixed together, from 1 to 40 weight percent of a liquid crystal polymer and 60 to 99 weight percent of a different, softer structural plastic matrix which is not a liquid crystal polymer, said liquid crystal polymer defining a separate phase from said structural plastic matrix, said first layer exhibiting at least a degree of circumferential orientation to provide an increased amount of rotational stiffness to at least a section of said catheter body, said separate phase of the liquid crystal polymer defining generally helically extending fibrils dispersed throughout essentially the entire volume of said first layer, said fibrils being formed from liquid crystal polymer plastic droplets dispersed in said structural plastic matrix.
Claim 3
Dependent Claim
22 words
The catheter of claim 1 in which said catheter body carries a second layer of a polymer formulation having tissue compatible characteristics.
Claim 4
Dependent Claim
25 words
The catheter of claim 1 in which various sections of said catheter body exhibit differing degrees of circumferential orientation of said fibrils and rotational stiffness.
Claim 5
Dependent Claim
18 words
The catheter of claim 1 in which said fibrils generally exhibit an aspect ratio of 10 to 300.
Claim 6
Dependent Claim
28 words
The catheter of claim 1 in which said liquid crystal polymer exhibits a greater propensity than poly(ethylene terephthalate) to orient during melt flow and to retain such orientation.
Claim 7
Dependent Claim
18 words
The catheter of claim 1 in which said catheter body is free of any added fibrous support means.
Claim 8
Dependent Claim
21 words
The catheter of claim 1 in which said liquid crystal polymer comprises a prepolymer of poly(ethylene terephthalate), reacted with p-hydroxybenzoic acid.
Claim 9
Dependent Claim
25 words
The catheter of claim 1, in which said liquid crystal polymer plastic-containing material comprises from 5 to 35 weight percent of said liquid crystal polymer.
Claim 10
Dependent Claim
22 words
The catheter of claim 1 in which said liquid crystal polymer is a terpolymer of hydroxybenzoic acid, ethylene glycol, and terephthalic acid.
Claim 11
Dependent Claim
28 words
The catheter of claim 1 in which substantially all of said fibrils extend longitudinally along said tube for no more than a minor portion of the length thereof.
Claim 12
Dependent Claim
127 words
An extruded plastic tubing which defines a tubular body, said tubular body defining a tubular layer which comprises a mixture of a minor portion of a liquid crystal polymer and a major portion of a structural plastic matrix which is not a liquid crystal polymer, said liquid crystal polymer defining a separate phase from said structural plastic matrix with the structural plastic matrix and the liquid crystal polymer phases comprising a blended mixture which is dispersed together, said tubular layer exhibiting at least a degree of circumferential orientation to provide an increased amount of rotational stiffness to at least a section of said tube, the separate phase of said liquid crystal polymer defining generally helically extending fibrils dispersed throughout essentially the entire volume of said tubular layer.
Claim 13
Dependent Claim
127 words
An extruded plastic tubing which defines a tubular body, said tubular body defining a tubular layer which comprises a mixture of a minor portion of a liquid crystal polymer and a major portion of a structural plastic matrix which is not a liquid crystal polymer, said liquid crystal polymer defining a separate phase from said structural plastic matrix with the structural plastic matrix and the liquid crystal polymer phases comprising a blended mixture which is dispersed together, said tubular layer exhibiting at least a degree of circumferential orientation to provide an increased amount of rotational stiffness to at least a section of said tube, the separate phase of said liquid crystal polymer defining generally helically extending fibrils dispersed throughout essentially the entire volume of said tubular layer.
Claim 14
Dependent Claim
23 words
The plastic tube of claim 11 in which said structural plastic matrix is made of a softer material than said liquid crystal polymer.
Claim 15
Dependent Claim
30 words
The plastic tube of claim 11 which comprises from 1 to 40 weight percent of said liquid crystal polymer and 60 to 99 weight percent of said structural plastic matrix.
Claim 16
Dependent Claim
19 words
The plastic tube of claim 11 in which said fibrils generally exhibit an aspect ratio of 10 to 300.
Claim 17
Dependent Claim
29 words
The plastic tube of claim 11 in which said liquid crystal polymer exhibits a greater propensity than poly(ethylene terephthalate) to orient during melt flow and to retain such orientation.
Claim 18
Dependent Claim
19 words
The plastic tube of claim 11 in which said catheter body is free of any added fibrous support means.
Claim 19
Dependent Claim
22 words
The plastic tube of claim 11 in which said liquid crystal polymer comprises a prepolymer of poly(ethylene terephthalate), reacted with p-hydroxybenzoic acid.
Claim 20
Dependent Claim
26 words
The plastic tube of claim 11 in which said liquid crystal polymer plastic-containing material comprises from 5 to 35 weight percent of said liquid crystal polymer.
Claim 21
Dependent Claim
29 words
The plastic tube of claim 11 in which substantially all of said fibrils extend longitudinally along said tube for no more than a minor portion of the length thereof.
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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) | 1996-09-27 | 1997-03-29 | 1997-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-27 | 2001-03-29 | 2001-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-27 | 2005-03-29 | 2005-09-28 | $7700.00 | Window Closed / Lapsed |