US4436689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polymer filaments having high tensile strength
Assignee: DSM BV
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Filing: 1982-10-18
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Granted: 1984-03-13
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Expires: 2002-10-18
Abstract
Abstract An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and thereafter stretching the filament thus formed. A solution of an ethylene polymer or copolymer, containing at least 80 percent by weight solvent, is spun at a temperature above the gel point of the solution. The ethylene polymer or copolymer contains at most about 5 percent by weight of an alkene having 3 to 8 carbon atoms, has a weight-average molecular weight Mw higher than 4x105 kg/kmole, and has a weight/number average molecular weight ratio Mw/Mn lower than 5. The spun polymer solution is thereafter cooled to a temperature below its gel point to form a gel filament, which gel filament is thereafter stretched to form a polymer filament having a tensile strength of at least about 1.5 GPa at room temperature.
Inventors
- 👤 Paul Smith
- 👤 Pieter J. Lemstra
- 👤 Robert Kirschbaum
- 👤 Jacques P. L. Pijpers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:45
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/04; D01D; D01D5/00; D01D5/04
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
156 words
An improved process for the preparation of polyethylene filaments having a high tensile strength and modulus by spinning a solution of linear high-molecular weight polyethylene and thereafter stretching the filament thus formed, the improvement essentially comprising: spinning a solution of an ethylene polymer or copolymer at a temperature above the gel point of said solution, said solution containing at least 80 percent by weight solvent, and wherein said ethylene polymer or copolymer contains at least 5 percent by weight of at least one alkene having 3 to 8 carbon atoms; has a weight-average molecular weight Mw greater than 4×10 5 k/kmole; and has a weight/number average molecular weight ratio Mw/Mn lower than 5; cooling the spun polymer solution to a temperature below its gel point to form a gel filament; and stretching said gel filament under conditions such that a polymer filament having a tensile strength of at least 1.5 GPa at room temperature is formed.
Claim 2
Dependent Claim
156 words
An improved process for the preparation of polyethylene filaments having a high tensile strength and modulus by spinning a solution of linear high-molecular weight polyethylene and thereafter stretching the filament thus formed, the improvement essentially comprising: spinning a solution of an ethylene polymer or copolymer at a temperature above the gel point of said solution, said solution containing at least 80 percent by weight solvent, and wherein said ethylene polymer or copolymer contains at least 5 percent by weight of at least one alkene having 3 to 8 carbon atoms; has a weight-average molecular weight Mw greater than 4×10 5 k/kmole; and has a weight/number average molecular weight ratio Mw/Mn lower than 5; cooling the spun polymer solution to a temperature below its gel point to form a gel filament; and stretching said gel filament under conditions such that a polymer filament having a tensile strength of at least 1.5 GPa at room temperature is formed.
Claim 3
Dependent Claim
132 words
An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and stretching the gel filament thus formed, the improvement essentially comprising spinning a solution of a linear polymer or copolymer capable of forming a polymer or copolymer gel, said polymer or copolymer solution containing at least 80 percent by weight solvent relative to said solution, at a temperature above the gel point of said solution, cooling the spun polymer solution thus formed to a temperature below its gel point to form a gel filament, and stretching said gel filament while simultaneously twisting said filament around its axis, under conditions such that a polymer filament having a tensile strength of at least 1.5 GPa at room temperature is formed.
Claim 4
Dependent Claim
132 words
An improved process for the preparation of polymer filaments having a high tensile strength and modulus by spinning a solution of high-molecular weight polymer and stretching the gel filament thus formed, the improvement essentially comprising spinning a solution of a linear polymer or copolymer capable of forming a polymer or copolymer gel, said polymer or copolymer solution containing at least 80 percent by weight solvent relative to said solution, at a temperature above the gel point of said solution, cooling the spun polymer solution thus formed to a temperature below its gel point to form a gel filament, and stretching said gel filament while simultaneously twisting said filament around its axis, under conditions such that a polymer filament having a tensile strength of at least 1.5 GPa at room temperature is formed.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein said ethylene polymer or copolymer has a weight/number-average molecular weight ratio Mw/Mn lower than 4.
Claim 6
Dependent Claim
20 words
The process of claim 1 wherein said gel filament is stretched with a stretch ratio which is at least ##EQU2##
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein said gel filament, at the commencement of stretching, contains at least 25 percent by weight solvent.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein said gel filament, at the commencement of stretching, contains at least 50 percent by weight solvent.
Claim 9
Dependent Claim
18 words
The process of claim 1 wherein said gel filament, at the commencement of stretching, contains virtually no solvent.
Claim 10
Dependent Claim
19 words
The process of claim 1 wherein said gel filament during said stretching, is simultaneously twisted around its stretching axis.
Claim 11
Dependent Claim
33 words
The process of claim 2 wherein said gel filament is twisted in a manner such that the resulting polymer filament has from between about 300 to 3000 twists per meter of filament length.
Claim 12
Dependent Claim
33 words
The process of claim 8 wherein said gel filament is twisted in a manner such that the resulting polymer filament has from between about 300 to 3000 twists per meter of filament length.
Claim 13
Dependent Claim
22 words
The process of claim 2 wherein said gel filament, at the commencement of stretching, contains at least 25 percent by weight solvent.
Claim 14
Dependent Claim
22 words
The process of claim 2 wherein said gel filament, at the commencement of stretching, contains at least 50 percent by weight solvent.
Claim 15
Dependent Claim
18 words
The process of claim 2 wherein said gel filament, at the commencement of stretching, contains virtually no solvent.
Claim 16
Dependent Claim
20 words
The process of claim 1 wherein said polyethylene gel filament is stretched at a temperature between 75 and 135° C.
Claim 17
Dependent Claim
30 words
The process of claim 2 wherein said high-molecular weight polymer is selected from the group consisting of polyethylene, polypropylene, ethylene-propylene copolymers, polyoxymethylene, polyethyleneoxide, polyamides, polyesters, polyacrylonitrile, polyvinylalcohol, and polyvinylidene fluoride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
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