EP0415783A2
Expired / Lapsed
EP
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Thermal treatment of thermoplasticc filaments and filaments
Assignee: Ethicon Inc
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Filing: 1990-08-31
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Granted: —
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Expires: 2010-08-31
Abstract
Abstract Thermoplastic monofilament sutures having improved flexibility and handling characteristics are obtained by a melt spinning process which includes the step of drawing the filaments in a heated zone maintained at a temperature above the melting temperature of the filament. The resulting filaments have a higher elongation and lower modulus than comparable filament obtained without the heated drawing step, and are characterized by a crystalline structure which is more highly ordered in the core of the filament than in a surrounding annular area.
Inventors
- 👤 Ephraim Broyer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:55
CPC Classifications
B; B29; B29C; B29C55/00; A; A61; A61L; A61L17/00; A61L17/04; A61L17/06; A61L17/10; A61L17/105; A61L17/12; A61L17/14; D; D01; D01D; D01D10/00; D01D10/02; D01D5/00; D01D5/12; D01D5/16
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
121 words
In a method for producing a monofilament structure of a thermoplastic polymer composition comprising the steps of melt extruding and quenching the polymer to form a continuous filament, drawing the filament to achieve molecular orientation, and thereafter relaxing or annealing the filament to relieve internal stresses, the improvement comprising exposing the filament to a temperature in excess of the melting temperature of the polymeric composition during or subsequent to drawing said filament and prior to the final relaxation or annealing of said drawn filament, said exposure being for a time and at a temperature effective to obtain a filament having a lower order of crystallinity in the outer core area and a higher order of crystallinity in the inner core area.
Claim 2
Dependent Claim
121 words
In a method for producing a monofilament structure of a thermoplastic polymer composition comprising the steps of melt extruding and quenching the polymer to form a continuous filament, drawing the filament to achieve molecular orientation, and thereafter relaxing or annealing the filament to relieve internal stresses, the improvement comprising exposing the filament to a temperature in excess of the melting temperature of the polymeric composition during or subsequent to drawing said filament and prior to the final relaxation or annealing of said drawn filament, said exposure being for a time and at a temperature effective to obtain a filament having a lower order of crystallinity in the outer core area and a higher order of crystallinity in the inner core area.
Claim 3
Dependent Claim
19 words
The method of Claim 1 wherein said exposure occurs during the first drawing of the extruded and quenched filament.
Claim 4
Dependent Claim
29 words
The method of Claim 1 wherein said exposure occurs after the first drawing of said extruded and quenched filament, and said filament is maintained under tension during said exposure.
Claim 5
Dependent Claim
37 words
The method of Claim 1 wherein said filament is exposed a first time during a first drawing of said extruded and quenched filament, and is exposed a second time during a second drawing of said drawn filament.
Claim 6
Dependent Claim
24 words
The method of Claim 1 wherein said first drawing is in excess of 200 percent and said second drawing is less than 100 percent.
Claim 7
Dependent Claim
25 words
The method of Claim 1, wherein the outer core area has a radial thickness of from about 0.1 to 0.5x the radius of the filament.
Claim 8
Dependent Claim
22 words
Method of Claim 1 wherein said temperature of exposure is from about 5 to 100°C above the melting temperature of said polymer.
Claim 9
Dependent Claim
17 words
Method of Claim 7 wherein the time of said exposure is from about 0.1 to 5 seconds.
Claim 10
Dependent Claim
38 words
Method of Claim 1 wherein said thermoplastic polymer is selected from the group consisting of polyethylene, polypropylene, polyvinylidene fluoride, poly(glycolide, cotrimethyl carbonate), homopolymers and copolymers of lactide and glycolide and copolymers of p-dioxanone with lactide, glycolide and ε-caprolactone.
Claim 11
Dependent Claim
9 words
Method of Claim 1 wherein said polymer is poly(p-dioxanone).
Claim 12
Dependent Claim
37 words
Method of Claim 10 wherein said extruded and quenched monofilament is drawn 4 to 6x while being exposed to a temperature of from about 105°C to 175°C for a period of from about 0.1 to 5 seconds.
Claim 13
Dependent Claim
21 words
Method of Claim 11 wherein said filament is drawn 5x while being exposed to a temperature of about 120 to 140°C.
Claim 14
Dependent Claim
41 words
Method of Claim 11 wherein said drawn and exposed filament is redrawn about 5 to 30% while being exposed a second time to a temperature of from about 105 to 175°C for a period of from about 0.1 to 5 seconds.
Claim 15
Dependent Claim
29 words
The method of Claim 13 wherein said redrawn and exposed filament is relaxed by shrinking 10 to 25% of its redrawn length at a temperature below its melting point.
Claim 16
Dependent Claim
27 words
The method of Claim 14 wherein said filament is annealed after relaxation at a temperature of from about 70 to 90°C while being restrained against further shrinkage.
Claim 17
Dependent Claim
49 words
A drawn and oriented monofilament structure comprising a thermoplastic polymer and having a structure defined by an outer surface, a central core, and annular portion between said central core and said outer surface, said central core having a crystalline structure which is differentiated from that of said annular portion.
Claim 18
Dependent Claim
49 words
A drawn and oriented monofilament structure comprising a thermoplastic polymer and having a structure defined by an outer surface, a central core, and annular portion between said central core and said outer surface, said central core having a crystalline structure which is differentiated from that of said annular portion.
Claim 19
Dependent Claim
28 words
The monofilament of Claim 16 wherein said differentiation between said central core and said annular portion is readily visible by optical microscopy at 430x magnification under polarized light.
Claim 20
Dependent Claim
20 words
The monofilament of Claim 16 wherein said central core has a more highly ordered crystalline structure than said annular portion.
Claim 21
Dependent Claim
24 words
The monofilament of Claim 16 wherein the crystalline structure of the inner core is characterized by larger crystals as compared to the annual portion.
Claim 22
Dependent Claim
24 words
The monofilament of Claim 16 wherein the annular area has a radial dimension of from about 0.1 to 0.5x the radius of the monofilament.
Claim 23
Dependent Claim
38 words
The monofilament of Claim 16, wherein said polymer is selected from the group consisting of polyethylene, polypropylene, polyvinylidene fluoride, poly(glycolide, cotrimethyl carbonate), homopolymers and copolymers of lactide and glycolide and copolymers of p-dioxanone with lactide, glycolide and ε-caprolactone.
Claim 24
Dependent Claim
10 words
The monofilament of Claim 16 wherein said polymer is poly(p-dioxanone).
Claim 25
Dependent Claim
29 words
The monofilament of Claim 22 wherein said polymer has an average molecular weight of from about 65,000 to 100,000 and an intrinsic viscosity of from about 1.60 to 2.20.
Claim 26
Dependent Claim
27 words
The monofilament of Claim 23 wherein the crystalline structure of the inner core is characterized by larger and more spherolitic crystals as compared to the annular portion.
Claim 27
Dependent Claim
24 words
The monofilament of Claim 24 wherein the annular area has a radial dimension of from about 0.1 to 0.5x the radius of the monofilament.
Claim 28
Dependent Claim
27 words
The monofilament of Claim 22, having an elongation greater than 45%, a Young's modulus of less than 250,000 psi, and a ratio of Tenacity/Modulus greater than 0.30.
Claim 29
Dependent Claim
23 words
A surgical suture comprising a monofilament of any of Claims 16 to 26 having a diameter of from about 0.3 to 24 mils.
References Cited (Backward Citations)
No citation records indexed.
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