JP3166858B2 - Method for removing spinning solvent from spun fibers - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing spinning solvents from solution spun fibers. More particularly, the present invention relates to a method for extracting a spinning solvent from solution spun fibers, wherein the solution is prevented in a coagulating liquid, ie, a gelling liquid.

2. Prior Art Methods for producing fibers by the gel spinning method and the solution spinning method are known. For example, U.S. Pat.Nos. 4,413,110 and 4,455,2
No. 73, No. 4,536,536, No. 4,551,296, No. 4,440,
No. 711, No. 4,713,290, No. 4,883,628, No. 4,77
1,616, 2,509,279 and 4,334,102, Polymer Bulletin, Volume 1, 879-80 (1979), Po.
lymer, 2584-90 (1980), Polymer Bull., Vol. 2, 7
75-83 (1908), Soc Chem Ind, London, Monograph 3
0, 188-207 (1968), Applied Polymer Symposia,
No. 6, pages 109 to 49 (1967), West German Patent Publication No. 300
4699 (August 21, 1980), UK Patent Application 2,051,667
Issue (February 21, 1981), Polymer Bulletin, Volume 1, 879
Pp. 880 (1979) and 2, 775-83 (1908), and Polymer 2584-909 (1980).

SUMMARY OF THE INVENTION One aspect of the present invention includes the following: (a) extracting a continuous length of fiber containing a first spinning solvent with a second extraction solvent for a sufficient contact time, Forming a fiber of a solution of the spinning solvent and the second extraction solvent and containing the second extraction solvent, containing no or substantially no first solvent, and having a substantially infinite length; Wherein the second extraction solvent is: (i) the first spinning solvent is soluble or substantially soluble at a _first temperature T ₁ and insoluble at a _second temperature T ₂ Or it is substantially insoluble, so that the second
Extraction solvent can form a first solution consisting of the second extraction solvent and the first spinning solvent by extracting the first spinning solvent from the fibers at the first temperature T _1, thus also the second When one solution is subjected to the second temperature T ₂ , two different liquid phases, a first liquid phase mainly consisting of the first spinning solvent and a second liquid phase mainly consisting of the second extraction solvent, The first consisting of
A second extraction solvent, which forms a heterogeneous mixture of: (ii) said first spin solvent is soluble or substantially soluble, and is immiscible in said first spin solvent. A second extraction solvent that is soluble or substantially soluble in a third extraction solvent, wherein the second extraction solvent is relatively soluble in the first spinning solvent and in the third extraction solvent. The solubility is such that the third extraction solvent partially or totally extracts the second extraction solvent from a second solution consisting of the second extraction solvent and the spinning solvent to obtain two different liquid phases; Said second extraction solvent forming a second heterogeneous liquid mixture consisting of a third liquid phase consisting of one spinning solvent and a fourth liquid phase consisting mainly of said second extraction solvent and said third extraction solvent; (B) mixing the first solution with the first solution By subjecting a sufficient time the second temperature T ₂ in forming a homogeneous mixture, or sufficient time the second solution in forming the second heterogeneous liquid mixture in the third extraction solvent A step of separating the first solution or the second solution by extraction to form the first and second liquid phases, and (c) the second liquid phase or the fourth liquid phase to the extraction step. A method of extracting a substance from a fiber, comprising the step of recirculating.

Another aspect of the present invention is the step of forming a solution in a first spinning solvent with a polymer having a fiber-forming molecular weight, wherein the spinning temperature is higher than the temperature at which a rubbery gel forms upstream of the spinning holes; Extruding the solution at substantially the first concentration from the spinning hole both upstream and downstream of the spinning hole, wherein the solution adjacent to the spinning hole and downstream thereof is below the temperature at which a rubbery gel is formed. Cooling to a second temperature to form a substantially infinite length of the first solvent-containing gel, wherein the first solvent-containing gel is a second solvent containing the second solvent Extracting for a contact time sufficient to form a substantially infinite length of fibrous structure substantially free of; drying the second solvent-containing fibrous structure to dry the first and second fibrous structures; 2 virtually infinite length without solvent To produce a xerogel,
And a gel spinning method comprising the step of stretching at least one of the first solvent-containing gel, the second solvent-containing fibrous structure, and the xerogel, wherein: (a) a continuous method containing a first spinning solvent; The fiber of the length obtained is extracted with a second extraction solvent for a sufficient contact time, and the first solvent containing the extracted first spinning solvent, the solution in the second extraction solvent, and the second extraction solvent is removed. Forming a substantially infinite length of free or substantially free fibers, wherein the second extraction solvent is: (i) the first spinning solvent is at a first temperature T _1. in a or is substantially variable soluble, and is with or substantially insoluble in the second insoluble at temperatures T _2, the order that second
Extraction solvent can form a first solution comprising the second extraction solvent and the first spinning solvent by extracting the first spinning solvent from the fibers at the first temperature T _1, thus also the second When one solution is subjected to the second temperature T ₂ , two different liquid phases, a first liquid phase mainly consisting of the first spinning solvent and a second liquid phase mainly consisting of the second extraction solvent, The first consisting of
A second extraction solvent, which forms a heterogeneous mixture of: (ii) said first spin solvent is soluble or substantially soluble, and is immiscible in said first spin solvent. A second extraction solvent that is soluble or substantially soluble in a third extraction solvent, wherein the second extraction solvent is relatively soluble in the first spinning solvent and in the third extraction solvent. The solubility is such that the third extraction solvent partially or totally extracts the second extraction solvent from a second solution consisting of the second extraction solvent and the spinning solvent, so that two different liquid phases, namely the second Said second extraction solvent forming a second heterogeneous liquid mixture consisting of a third liquid phase consisting of one spinning solvent and a fourth liquid phase consisting mainly of said second extraction solvent and said third extraction solvent; (B) combining the first solution with the first solution Subjecting the second solution to the second temperature T ₂ for a time sufficient to form a heterogeneous mixture, or sufficient time to form the second solution with the third extraction solvent to form the second heterogeneous liquid mixture. A step of separating the first solution or the second solution into the first and second liquid phases by extracting, and (c) extracting the second liquid phase or the fourth liquid phase. And an improved gel spinning method comprising the step of:

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and other advantages will become apparent when reference is made to the following detailed description of the invention and the accompanying drawings, which are schematic illustrations of preferred embodiments of the invention. There will be.

DETAILED DESCRIPTION OF THE INVENTION In its broadest aspect, the present invention relates to a method for extracting a spinning solvent from a polymer fiber spun from a solution of the polymer in a spinning solvent. In this method, a continuous length of fiber containing a first spinning solvent is contacted with a second extraction solvent that is a non-solvent for the polymer of the fiber to form a mixture of two solvents or Form a solution. As used herein, fibers are elongates whose elongate dimension is significantly larger than their width and thickness dimensions. Thus, the term fiber encompasses yarns, yarns, filaments, both multifilament and monofilament, yarns containing multiple filaments, tapes, ribbons, strips, etc., having a regular or irregular cross section. I do. As used herein, "solvent" means a fluid that is liquid under processing conditions and that can extract or remove the spinning solution from the solution spun fibers in any manner.

The means for contacting the fiber-containing spun with the extraction solvent is not critical, and any conventional extraction means can be used.
For example, the extraction solvent and the fibers can be contacted by countercurrent or cocurrent techniques. In a preferred embodiment of the present invention, fibers containing an extraction solvent and a spinning solvent are contacted using the apparatus and method of US Pat. No. 4,771,616.

The fiber containing the extractable solvent and the spin solvent is contacted for a time sufficient to extract all or substantially all of the spin solvent from the fiber and replace the spin solvent with a second extraction solvent. Generally, the residual amount of spinning solvent remaining in the fiber after extraction is at most about 15% by weight of the fiber. More preferably, the amount of residual spin solvent is no more than about 5% by weight of the fiber, and most preferably no more than about 1.5% by weight.

The extraction time may vary widely, such that the desired amount of spinning solvent is extracted. The extraction time depends on a number of factors such as, for example, the extraction temperature, the solubility of the spinning solvent in the extractable solvent, and the like. Normally, extraction times vary from minutes or seconds to hours or days. A preferred extraction time is from about 30 seconds to about 24 hours, with a more preferred extraction time being about 30 seconds.
Seconds to about 30 minutes, and the most preferred extraction time is about 30
Seconds to about 10 minutes.

Useful extraction temperatures vary widely depending on a number of factors, especially the solubility of the spinning solvent in the extraction solvent at a given temperature. Preferably, the extraction step is at ambient temperature, ie, about 20 ° C.
Performed at ~ 30 ° C.

The number of contacts may vary widely and depends to a considerable extent on the mutual solubility of the first spinning solvent and the second extraction solvent at the contact temperature. For example, if the mutual solubility and fiber porosity are high and the amount of spin solvent contained in the fiber is low, the desired amount of spin solvent can be removed in a very low one contact cycle. However, on the other hand, if the mutual solubility and porosity of the fiber are low and the amount of spinning solvent in the fiber is high, then one or more contact cycles are required to extract the desired amount of spinning solvent from the fiber. In general, the contact time and cycle should be such that the residual spin solvent remaining in the fiber is in the desired amount, preferably not more than about 5% by weight of the fiber, and most preferably not more than about 1.5% by weight of the fiber. To be elected.

The second extraction solvent varies widely, provided that it is a solvent for the spinning solvent and is capable of extracting the desired amount of spinning solvent from the fiber, and preferably all or substantially all of the spinning solvent from the fiber. Is also good. The first extraction solvent is also preferably such that the first spinning solvent can be separated from the extraction solvent for recycling. In one preferred embodiment of the invention, the second extraction solvent is a solvent for the spinning solvent at a temperature, soluble in a third extraction solvent that is insoluble in the spinning solvent, and wherein the spinning solvent and the third Wherein the third extraction solvent is capable of extracting the second extraction solvent from a solution comprising the spinning solvent and the second extraction solvent. In this preferred embodiment of the present invention, the spinning and third extraction solvent can be separated by solvent extraction.

In another preferred embodiment of the present invention, the second extraction solvent is a solvent for the first spin solvent at a first temperature T ₁ and a non-solvent for the first spin solvent at a _second temperature T ₂ . a non-solvent for the polymer to form fibers in the first both temperature T ₁ and the second temperature T _2, having a boiling point higher than the highest temperature used for the performance of the extraction step at 76 mmHg. In this embodiment of the invention, the second extraction and first spin solvent can be separated by changing the temperature of the spin and extraction solvent solution.

Extraction solvents having the desired properties can be identified by use of solubility and boiling point studies. The extraction solvent will depend to a most significant extent on the spin solvent.
The spin solvent will vary depending on the polymer forming the fiber. For example, if the fibers are formed from polyvinyl alcohol, the spinning solvent is preferably from about 150 to 300
Aliphatic and aromatic alcohols such as hydrocarbon polyols and alkylene ether polyols having a boiling point at 101 ° C. (at 101 kPa). Such solvents include:
Examples include ethylene glycol, glycerin, propylene glycol, glycerol, diethylene glycol and triethylene glycol. If the fibers are formed from polyacrylonitrile, useful spin solvents include dimethyl sulfoxide, dimethylformamide, and the like. Similarly, when the polymer forming the fiber is a polyolefin, such as polyethylene, polypropylene and copolymers of ethylene and propylene, the spinning solvent is preferably mineral oil, paraffin oil, decalin, polyethylene wax and mixtures thereof. Such aliphatic and aromatic hydrocarbons. In these cases, useful extraction solvents having the desired properties may be identified by routine temperature / solubility studies. For example, in a preferred embodiment of the invention where the fibers are formed from a polyolefin, preferably polyethylene, and the spinning solvent is a hydrocarbon, preferably mineral oil, paraffin oil or decalin, the extraction solvent is preferably diethylene glycol monobutyl ether and diethylene glycol monopropyl. It is a polyether solvent such as ether.

In addition to the intrinsic boiling point and solubility properties, the extraction solvent for use in the preferred embodiment of the present invention is also about 87.8
Flash point equal to or higher than 0 ° C (open), boiling point at 760 mmHg equal to or higher than about 190 ° C, vapor pressure at 25 ° C equal to or lower than about 0.4 mmHg and chlorine-free atoms in the solvent structure Is shown.

More preferred extraction solvents are polyether solvents. Useful polyether solvents are described in U.S. Pat. No. 3,737,392.

Preferred polyether solvents are polyalkylene glycols having alkyl groups of 1 to about 5 carbon atoms (particularly methyl and ethyl) and alkylene groups of 2 to about 6 carbon atoms (particularly ethylene) and alkylene moieties of 2 to about 6 carbon atoms. Or a monoalkyl ether or dialkyl ether of a polyalkylene glycol having the formula: An example of such a preferred solvent is polypropylene glycol (about 425
Molecular weight of about 1200), tetraethylene glycol dimethyl ether (tetraglyme), triethylene glycol dimethyl ether (triglyme), diethylene glycol dimethyl ether (diglyme), diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, tripropylene glycol, diethylene glycol monomethyl ether, diethylene glycol divinyl ether , Diethylene glycol monoisobutyl ether, diethylene glycol dibutyl ether, diethylene glycol monopropyl ether, triethylene glycol, tetraethylene glycol, diethylene glycol tert-butyl methyl ether, diethylene glycol diethyl ether, and propylene glycol monomethyl It is an ether.

A preferred group of the polyether solvent, the following _{formula: R 3 (OCH 2 CH 2} ) x OR 1 and _{R (OCH 2 CH (CH 3} )) x OR 1 ( wherein, x is an integer from 1 to about 8 And R ¹ and R ¹ are the same or different and are hydrogen or alkyl having about 1 to about 4 carbons), and mixtures of such glycol ethers. More preferred polyether solvents are of the formula: R (OCH ₂ CH ₂ ) _x OR ¹ , wherein x is an integer from about 2 to about 5, R and R ¹ are the same or different and preferably R And hydrogen, methyl, provided that at least one of R ¹ is other than hydrogen.
Ethyl, propyl or butyl). The most preferred solvents are tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether and diethylene glycol monopropyl ether, with diethylene glycol monobutyl ether and diethylene glycol monopropyl ether being the selected solvents.

Useful preferred polyether solvents are prepared by conventional methods such as acid catalyzed polymerization of propylene oxide, ethylene oxide and mixtures of propylene oxide and ethylene oxide. Such solvents can also be obtained from commercial sources. For example, such materials are under the trademark Pl
uracol polyethylene glycol E200, E30, E400 and E
600 and Pluracol polypropylene glycol P410 from Wyandotte Corporation and under the trademark Polyglyco
l Can be obtained from Dow Corporation under P400. Glycol ethers are, for example, EKTASOLV DP
And EKTASOLV DB from Eastman Kodak, for example Butyl CARBITOL from Union Carbide, and for example diethylene glycol DB and diethylene glycol HB from Oxy Chem, Tetraglyme
Can be obtained from Ferro Corp.

The polymer for the fiber may vary widely, the only requirement is that the polymer be soluble in the spinning solvent and insoluble in the extraction solvent. Illustrative examples of useful polymers include polyamides and polymetaphenylene isophthalamide, poly p-phenylene terephthalamide, 30% hexamethylene diammonium isophthalate and 70% hexamethylene diammonium adipate copolyamide, 30% bisamidocyclohexylmethylene, terephthalic Their copolymers, such as copolyamides of acids and caprolactam,
Polyhexamethylene adipamide (nylon 66), poly 6
-Aminohexanoic acid (nylon 6), poly 11-aminoundecanoic acid (nylon 11), polyhexamethylene sebacamide (nylon 6, 10), etc .; α, β- such as polyacrylonitrile, polyvinyl alcohol and polyacrylic acid
Polymers and copolymers formed by the polymerization of unsaturated olefins, for example polyolefins such as polyethylene and polypropylene, copolymers of vinyl acetate and vinyl chloride; and polybutylene terephthalate, polyethylene terephthalate and poly 1,4-cyclohexanediene It is a polyester such as methylene terephthalate. Preferred polymers are α, β- such as polyamides and polyolefins, especially polypropylene and polyethylene.
Polymers of unsaturated monomers, polyvinyl alcohol and polyacrylonitrile.

Polyethylene is the polymer of choice. As used herein, the term "polyethylene" may contain small amounts of chain branching or comonomers that do not exceed 5 modifying units per 100 main carbon atoms. And also no more than 50% by weight of alkene-1-polymers mixed with them, in particular,
One or more additives, such as low density polyethylene, polypropylene or polybutylene, copolymers containing monoolefins as the main monomer, oxidized polyolefins, grafted polyolefin copolymers and polyoxymethylene, or as per the literature Means mainly a linear polyethylene material which may contain low molecular weight additives such as antioxidants, lubricants, ultraviolet shielding agents, coloring agents, and the like, which are mixed into the polyethylene.

The polymer is of a fiber-forming molecular weight. Such molecular weights for various fiber-forming polymers are well known in the art and will not be described in detail. For example, in the case of the preferred polyethylene, polypropylene, polyacrylonitrile and polyvinyl alcohol, a suitable polymer is at least about 150,000, preferably at least about 1,000,000, more preferably about 1,000,000.
To about 5,000,000 and most preferably from about 2,000,000 to about 5,
It has a molecular weight of 000,000.

Solvent-containing fibers for use in the present invention can be conventionally manufactured by gel or solution spinning techniques. An example of such a procedure is U.S. Patent No. 4,457,985,
No. 4,137,394, No. 4,356,138, No.
No. 4,440,711, No. 4,713,290, No. 4,55
Nos. 1,296, 4,599,276 and 4,53
No. 5,027, West German Offenlegungsschrift 3,004,699, British Patent No. 2051667, and European Patent No. 64,167, all of which are incorporated herein by reference. . Therefore,
None of these methods will be described in detail. Of these methods, U.S. Patent Nos. 4,413,110 and 4,45
No. 5,273, No. 4,536,536, No. 4,551,29
Fibers formed by the spinning method described in JP-A-6, 440,771, JP-A-4,713,290 and JP-A-4,883,628 are preferred.

In these preferred methods, the appropriate polymer is dissolved in a suitable non-volatile solvent, usually in an amount of about 5 to about 15% by weight of the solution, preferably about 4 to about 10% by weight of the solution.

The fiber containing the spinning solution is extruded from the spinning hole at substantially the same concentration upstream and downstream of the hole at a temperature no lower than the first temperature upstream of the hole, and the temperature at which a rubbery gel is formed The solution is cooled adjacent and downstream of the hole to a second temperature below, producing a gel containing a substantially indeterminate length of spinning solvent.

The first solvent should be relatively non-volatile under the processing conditions. This is to maintain an essentially constant concentration of solvent upstream and from start to finish of the hole (die) and to reduce the non-uniformity of the liquid content of the gel fibers or films containing the first solvent. Necessary to prevent.
Preferably, the vapor pressure of the first solvent should not be greater than 180 ° C., ie, 80 kPa (4/5 of atmospheric pressure) at the first temperature. Suitable first spin solvents for useful polymers such as, for example, polyethylene, polyacrylonitrile, and polyvinyl alcohol are described above. For example, useful spin solvents for polyvinyl alcohol include the desired non-volatile and polymer soluble aliphatic or aromatic alcohols such as ethylene glycol, propylene glycol, glycerol, diethylene glycol and trimethylene glycol.
Hydrocarbon polyols and alkylene ether polyols having a boiling point (at 101 kPa) from about 150C to about 300C. Suitable spin solvents for polyolefins such as polyethylene are hydrocarbons such as decalin, mineral oil, polyethylene wax and mixtures thereof.
The solvent is preferably a mineral oil. The polymer preferably has a relatively narrow range, for example 2 to 15% by weight, preferably 4 to 10%.
It may be present in the first solvent at a first concentration selected from wt%. However, once chosen, the concentration should not be changed adjacent to the die or if not prior to cooling to the second temperature. The concentration should also remain reasonably constant over time (ie, the length of the fiber or film).

The temperature of the spinning solvent is chosen to achieve complete dissolution of the polymer in the first solvent. The temperature of the spinning solvent is preferably the lowest temperature at any point between where the solution is formed and the face of the die, and must be above the gelling temperature for the polymer in the first concentration of solvent. . 5-
For polyethylene in 15% strength mineral oil, the gelling temperature is approximately from about 100 to about 130 ° C. Therefore, the preferred spinning temperature for polyethylene in this solvent is from about 180 to
About 250 ° C., preferably about 200 to about 240 ° C. Similarly, for polyvinyl alcohol in glycerin at a concentration of about 5 to about 15%, the gelation temperature is about 25 to about 100 ° C.
It is. Therefore, the preferred spinning temperature for polyvinyl alcohol is about 130 to about 250 ° C, more preferably about 170 ° C.
~ 230 ° C. The temperature may be varied above the spinning temperature at various points upstream of the die surface, but excessive temperatures that act to cause polymer collapse should be avoided. To ensure complete solubility, the spinning temperature is selected where the solubility of the polymer exceeds the first concentration, and is typically at least 20% or more. The gelation temperature is
The first solvent-polymer system is chosen where it behaves as a gel, ie, where the system has a yield point and suitable dimensional stability for subsequent handling. Cooling of the extruded polymer solution from the spinning temperature to the gelling temperature is preferably rapid enough to produce gel fibers where substantially the same polymer concentration is likely to be present in the polymer solution. At a high speed. Preferably, the rate at which the pressed polymer solution is cooled from the spinning temperature to the second temperature is preferably at least 50 ° C / min.

A preferred means of rapidly cooling to the gelation temperature is to use a quench bath containing a liquid into which the extruded polymer solution is dropped after passing through an air gap (which may be an inert gas). No. Unfortunately, however, the quench liquid and the first solvent have only a limited amount of interaction. For example, if the spinning solvent is preferably polyvinyl alcohol, preferably glycerol,
The quench liquid is preferably a liquid such as paraffin oil.
Similarly, for the preferred polyacrylonitrile, wherein the spinning solvent is preferably dimethyl sulfoxide, a suitable quench solvent is preferably a liquid such as a mixture of water and dimethyl sulfoxide. In the case of the most preferred polyethylene fibers, the spinning solvent is preferably a hydrocarbon (preferably mineral oil) and the quench liquid is preferably water.

Preferred polyether solvents used as extraction solvents in the present invention can also function as quench liquids. When cooled, the spun fiber is substantially soluble in the extraction solvent at high temperature but insoluble at low temperature, the spun fiber is quenched at low temperature where the spin solvent is insoluble in the polyether solvent, and the spun fiber Can be quenched by contact with the solvent at a temperature low enough to Thereafter, the fibers may be contacted with the solvent at an elevated temperature to extract the spinning solvent. Some extension during cooling to the gelation temperature at which the gel forms is not excluded from the present invention, and the overall extension during this step should not normally exceed 10: 1. As a result of these factors, the gel fibers formed by cooling to the second temperature consist of a network of a continuous polymer that is highly swollen with solvent.

Oval, in which the major axis in a plane of circular cross-section (or in a plane perpendicular to the flow direction is not more than 8 times the smallest axis in the same plane,
If holes of different cross-sections (Y or X shaped holes) are used, both would be gels to gel fibers, xerogels to xerogel fibers and thermoplastic articles to fibers. The hole diameter is not critical, but typical holes have a diameter (or long axis) of 0.25-5 mm. The length of the hole in the direction of flow is usually at least 10
Times, preferably 15 times, and most preferably at least 20 times the diameter (or other similar long axis).

If rectangular cross-section holes are used, both gels will be gel films, xerogels will be xerogel films and thermoplastic articles will be films. The width and height of the holes are not critical; typical holes have a width (corresponding to the width of the film) of about 2.5 to about 2 mm and a height (corresponding to the thickness of the film) of about 0.25 to It is about 5mm. The depth of the holes (in the flow direction) should be at least 10 times the height of the normal holes, preferably at least 15 times the height, more preferably at least about 20 times the height.

The extraction step includes a first step in which the spinning solvent is soluble in the extraction solvent.
At a temperature of The spin solvent may be soluble to the extraction solvent and vary to some extent, the only requirement being that the solubility be such that the spin solvent is extracted from the fibers to the desired extent at the first temperature. The first temperature used will vary widely depending on the choice of spinning solvent and extraction solvent. For example, the spinning solvent is a hydrocarbon such as mineral oil, the extraction solvent is a polyalkylene glycol having an alkyl group of 1 to 5 carbon atoms, and each erylene group contains about 2 to about 6 carbon atoms. When the alkylene group and the monoalkyl or dialkyl ether of the polyalkylene glycol group, such as diethylene glycol monobutyl ether and diethylene glycol monopropyl ether, the first temperature is preferably from about 55 to about 100 ° C, more preferably from about 65 to about 100 ° C. ° C, and most preferably from about 75 to about 100 ° C.

The spinning solvent is in the desired degree (preferably about 15% by weight of the fiber
(Less than about 5.0% by weight, and most preferably about 1.5% by weight or less), and if the extraction solvent is sufficiently volatile, the extracted fibers can be extracted using conventional drying techniques. Dried. However, if the extraction solvent is not sufficiently volatile, the fibers may be extracted with a linear solvent that is more volatile and miscible with the extraction solvent. Washing replaces the extraction solvent in the gel with a more volatile washing solvent. Suitable washing solvents include water, low molecular weight alcohols such as methanol and ethanol,
Examples include low molecular weight ethers such as dimethyl ether, methyl ethyl ether, dioxane, and tetrahydrofuran, and ketones such as acetone and methyl ethyl ketone. For the preferred polyether solvents, water is the preferred washing solvent primarily for convenience.

Once the fibrous structure containing the washing or extraction solvent is formed, it is then dried under conditions in which the washing or extraction solvent is removed leaving a substantially intact polymer solid network. By analogy to silica gel, the resulting material is referred to as a "xerogel", which refers to a solid matrix corresponding to the solid matrix of a wet gel, with the liquid being displaced by a gas (eg, by an inert gas such as nitrogen or by air). Is referred to herein. The term "xerogel" is not intended to describe any particular type of surface area, porosity or pore size.

Elongation may be performed on the gel fibers after cooling to a temperature equal to or lower than the gelation temperature or during or after the extraction. Alternatively, stretching of the xerogel fibers may be performed, or a combination of gel stretching and xerogel stretching may be performed. Elongation may be performed in one stage, or in two or more stages. The first stage of elongation may be performed at room or elevated temperature. Preferably, the extension is performed in two or more stages where the last stage is performed at a temperature of 120-150 ° C. Most preferably, the elongation is at least 2 wherein the last stage is performed at a temperature of 130-150 ° C.
It takes place in stages. Said temperature may be achieved with heating tubes or other heating means such as heating blocks or steam jets.

After extraction, the solution containing the second extraction solvent and the first spinning solvent is preferably separated into two solvents, the spinning solvent is recycled to the solution production process, and the second extraction solvent is passed to the extraction process. Processed to be recycled. The manner in which the solution separates into the first and second portions may vary widely, and any conventional procedure may be used, for example, as in US Pat. No. 4,334,102. In one preferred embodiment of the present invention, the spinning solvent and the second extraction solvent are separated by solvent extraction of the second extraction solvent from the solution with a third extraction solvent. For example, if the second extraction solvent is a polyether such as triethylene glycol, triethylene glycol dimethyl ether, diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, or diethylene glycol dimethyl ether, the first spinning solvent and the second extraction solvent Separated by extracting the second extraction solvent from the solution with a third extraction solvent, which is a solvent for the second extraction solvent and a non-solvent for the first spinning solvent, the two liquid phases, mainly A heterogeneous mixture of one liquid phase, a first spinning solvent, and another liquid phase, a solution comprising the second and third extraction solvents, is produced. A portion containing primarily a first spin solvent (generally at least 80% by volume, preferably at least 90%, more preferably at least 95% by weight, based on the weight of the portion;
And most preferably at least 99% by volume) can be recycled to produce a polymer fiber spinning solution.

Liquids useful as third extraction solvents may vary widely provided they provide this function. Preferred third extraction solvents include lower critical solution temperature characteristics of the second and third extraction solvents, such as temperature-induced phase separation of diethyl carbitol and water, and also include a second extraction solvent of the second extraction solvent. It can be separated from the second extraction solvent by any suitable solvent separation technique, including also distillation, extraction, etc., which allows recycling to one spinning solvent extraction step. More preferred third extraction solvents are those that can be separated from the second extraction solvent by distillation. The third extraction solvent usually has a boiling point at least about 80 ° C, preferably at least about 110 ° C, more preferably at least about 150 ° C below the boiling point of the second extractant. Illustrative of such preferred third extraction solvents are water, alcohols such as ethanol, methanol and the like. More preferred third extraction solvents are water and alcohol, and most preferred third extraction solvent is water.

The mixture of the second and third extraction solvents is separated by use of a suitable separation technique (eg, as described above),
The concentration of the third extraction solvent in the second extraction solvent is such that the second extraction solvent is of sufficient purity to be recycled to the first spinning solvent extraction step. Similarly,
The concentration of the second extraction solvent in the third extraction solvent is of sufficient purity that the third extraction solvent can be recycled to the extraction process that includes separating the first extraction solvent from the second extraction solvent. Concentration. After separation, the second extraction solvent can be recycled directly to the fiber extraction step, or can be recycled to a further optional treatment, such as drying with some desiccant, such as, for example, molecular sieves; Can be recycled to the second extraction solvent extraction step.

In another preferred embodiment of the present invention, the second extraction solvent and the first extraction solvent can be separated by changing the temperature. For example, at a first temperature at which the two solvents are originally mutually soluble, a solution of the second extraction solvent and the spinning solvent may be heated or cooled to a temperature at which the solvent is immiscible to form a heterogeneous solvent. Generate a phase liquid system. One phase is a first phase that mainly comprises a spinning solvent, and the other phase is a second phase that mainly comprises an extraction solvent. Generally, the concentration of the primary solvent in each phase will generally be at least about 80%, preferably at least about 90%, more preferably at least about 90% by weight of that phase.
95% by weight, and most preferably at least 99% by weight.

The spin solvent is soluble in the extraction solvent and may vary widely to some extent, the only requirement being that the solubility be such that the spin solvent and the extraction solvent can be separated to the desired extent at a second temperature. is there. The second temperature used for any particular extraction will vary widely depending on the choice of spinning solvent and extraction solvent. For example, if the spinning solvent is a hydrocarbon such as mineral oil and the extraction solvent has an alkyl group of 1 to about 5 carbon atoms and the individual alkylene moieties contain about 2 to about 6 carbon atoms. For monoalkyl or dialkyl ethers of polyalkylene glycols having alkylene glycol groups, such as diethylene glycol monobutyl ether and diethylene glycol monopropyl ether, the second temperature is preferably from about 0 to about 45 ° C, more preferably from about 0 to about 30 ° C. And most preferably from about 0 to about 25 ° C.

A spinning solvent phase containing up to about 20% by weight, preferably up to about 10% by weight, more preferably up to about 5% by weight, and most preferably up to about 2% by weight, and preferably about 2% by weight % Of the extraction solvent phase containing less than or equal to% of the spinning solvent can be recycled to the solution generation step and the extraction step, respectively. If the desired concentration for recycling is not achieved, the equilibrium can be transferred to a hot solution comprising the spinning solvent and the extraction solvent by adding a small amount (1-2%) of a third component (eg, water). Can be. At the initial temperature where phase separation is promoted, if the required minimum concentration level is still not achieved, the various phases may be subjected to various other purification procedures such as distillation, solvent extraction, etc. Can be reduced to the desired concentration.

The fibers produced according to the method of the present invention can be used for conventional purposes in which the fibers are used using conventional fiber processing techniques. For example, if the fibers were formed from ultrahigh molecular weight linear polyethylene, such fibers would be, for example, U.S. Pat.Nos. 4,916,000, 4,623,574,
No. 4,403,012, No. 4,457,985, No. 4,65
No. 0,710, No. 4,681,792, No. 4,737,40
It can be used for the production of impact-resistant articles as described in JP-A No. 1,543,286, 4,563,392 and 4,501,856.

The following examples are provided to illustrate the invention in more detail and should not be construed as limiting the invention.

Example 1 The figure illustrates in schematic form the first embodiment of the invention, in which the drawing step I is carried out on the xerogel fibers in two stages following the drying step 4. FIG.
Shows a first mixing vessel 10 which is supplied with an ultra-high molecular weight polymer such as polyethylene having a weight average molecular weight of at least 500,000, and often at least 750,000, and to which a supply line 12 is provided. Also supplies mineral oil. The first mixing container 10 has a stirrer 13. The residence time of the polyethylene and mineral oil in the first mixing vessel 10 is sufficient to produce a slurry containing some dissolved polyethylene and some relatively finely divided polyethylene particles, and the polyethylene / mineral oil slurry is It is removed to the strong mixing vessel 15 via the line 14. Powerful mixing container
15 has a spiral stirring blade 16. The residence time in the intense mixing vessel 15 and its agitation rate are sufficient to convert the polyethylene / mineral oil slurry to a solution. The temperature in the intense mixing vessel 15 may depend on the external heating, the heating of the polyethylene / mineral oil slurry 14, the heat generated by the intense mixing, or any combination of the above, to convert the polyethylene to the desired concentration in mineral oil (generally relative to the solution). 5-10% by weight polyethylene) high enough to completely dissolve (eg 200
° C). The solution from the intense mixing vessel 15 is fed into the gear pump and housing 23 at a controlled flow rate inside.
A barrel 19 with a screw 20 driven by a motor 22 to send the polyethylene solution at a moderately high pressure
Is supplied to an extruder 18 having The motor 24 drives the gear pump 23 and may be of any of a variety of shapes, such as circular, X-shaped or oval, or if desired to form fibers, having a relatively small major axis in the plane of the spinneret. Also, when it is desired to form a film, a spinneret including a plurality of spinning holes, which can have a rectangular or other shape with a long major axis in the plane of the spinneret
Through 25 is provided to extrude the still hot polyethylene solution. The temperature of the solution in the mixing vessel 15, in the extruder 18, and in the spinneret 25 is all selected to exceed the gelation temperature for polyethylene in mineral oil (about 100-130 ° C) (eg, 200 ° C). Is equal to or greater than.

The temperature may vary from the mixing vessel 15 to the extruder 18 to the spinneret 25 (eg, 220 ° C., 210 ° C. and 220 ° C.) or may be constant (eg, 190
° C). However, in all respects, the concentration of polyethylene in the solution should be substantially the same. The number of spinning holes, and thus the number of fibers formed, is not critical, and convenient hole numbers are 16, 120, 240.

The polyethylene solution exiting the spinneret 25 may be filled, optionally surrounded by an inert gas such as nitrogen, and optionally supplied with a gas stream to facilitate cooling. Good, pass through the air gap 27. A plurality of gel fibers 28 containing mineral oil pass through an air gap 27 and enter a quench bath 30 containing any of a variety of liquids, and a quench bath with the air gap 27.
In both 30, the fiber is cooled to a second temperature where the solubility of the polyethylene in the mineral oil is relatively low so that the polyethylene / mineral oil system solidifies to form a gel. The quenching liquid in the quench bath 30 is preferably water. Some stretching is allowed in the air gap 27, but is preferably less than about 10: 1.

The rollers 31 and 32 in the quench bath 30 operate to feed the fibers through the quench bath, preferably with little or no stretching. Some stretching is with roller 31
If it occurs beyond 32, some mineral oil will seep out of the fiber, which can be collected as the top layer in the quench bath 30.

The cold first gel fibers 33 exiting the quench bath 30 are supplied with the extraction solvent through line 38 and the device 37 is operated at a third temperature T _3.
Has been maintained. Proceed to solvent extraction device 37. Extraction solvent is a solvent for the third in the temperature T ₃砿油, a polyether-based solvent is a non-solvent for the first 4, the temperature T ₄砿油. The extraction solvent is also a solvent for water, but non-solvent for polyethylene. The extraction solvent is preferably diethylene glycol monobutyl ether.
The extraction solvent extracts the mineral oil spinning solvent from the gel fibers to form a fibrous structure containing up to about 15% by weight mineral oil based on the weight of the fibers. The solvent outlet line 40 contains a solution consisting of a polyether extraction solvent and a mineral oil spinning solvent at a _third temperature T3 at which the extraction solvent and the spinning solvent are mutually soluble. The solution is conveyed via line 40 to a solvent separator 41 where the extraction solvent substantially separates the solution into a mineral oil rich phase and a polyether extraction solvent rich phase.
Is cooled to the temperature of The spinning solvent phase is conveyed to mixer 10 by lines 42 and 11, while the extraction solvent phase is conveyed to solvent extraction unit 37 via lines 43 and 38.

The fibrous structure 44 derived from the solvent extraction device 37 contains substantially only the extraction solvent and a relatively small amount of mineral oil. The fibrous structure 44 will be slightly shrunk compared to the true gel fiber 33. The fibrous structure 44 is then conveyed to a washing chamber 45, where the structure 44 containing the extraction solvent is washed with a washing solvent in which the extraction solvent is soluble to remove the extraction solvent from the structure 44. The washing solvent has a higher volatility than the extraction solvent (boiling point above about 100 ° C.). Preferably, the washing solvent is a low molecular weight alcohol such as methanol and ethanol, and water. The preferred washing solvent is water. Structure 44 is washed for a period of time sufficient to remove the extraction solvent from structure 44 up to 95% by weight, preferably up to 99% by weight, more preferably up to 99.8% by weight based on the original concentration of the extraction solvent. Is done. The solution of the washing solvent and the extraction solvent is conveyed by a pipe 47 to a solvent recovery device 46 where the washing solvent and the extraction solvent are separated. The cleaning solvent is supplied to the cleaning chamber via line 48.
The extraction solvent is returned to 45, while the extraction solvent is
Is returned to. Additional extraction and washing solvents can be introduced into the system via line 66.

The washed fibrous structure 50 is carried to the drying device 51. In the drying device 51, the cleaning solvent is evaporated from the fibrous structure 50 to form an essentially undrawn xerogel fiber 52, which is taken up by a spool 53.

If it is desired to operate the drawing system at a feed rate slower than the take-up of the spool 53, from the spool 53 or from a plurality of such spools, the fibers are transferred from the driven feed roll 54 onto the idler roll 55. Through the first, which can be rectangular, cylindrical or any other convenient shape
Is supplied into a heating tube 56. Sufficient heat is applied to tube 56, which can be rectangular, cylindrical, or any other convenient shape. Sufficient heat is applied to tube 56 to reduce fiber temperature to 12
Bring to 0-140 ° C. The fibers are drawn at a relatively high draw ratio (eg, 5: 1) to form partially drawn fibers 57 that are taken up by drive roll 58 and play roll 59. From the rolls 58 and 59, the fiber is drawn through a second heating tube 60 and at a somewhat higher temperature, e.g.
A drive take-off roll 61 and an idler roll that are heated to about 160 ° C. and are operated in a heating tube 60 at a speed sufficient to provide the desired draw ratio, for example, 18: 1.
Taken by 62. The twice-drawn fiber 63 produced in the first embodiment is taken up by a take-up spool 64.

For the nine process steps of the present invention, it can be seen that solution generation step A is performed in mixers 13 and 15. The extrusion step B is carried out by the devices 18 and 23, in particular through the spinneret 25. The cooling step C is performed in the air gap 27 and the quench bath 30. The extraction step D is performed in the solvent extraction device 37. The separation step E between the extraction solvent and the spinning solvent is a separator.
It takes place in 41. The fiber cleaning step F is performed in the cleaning chamber 45. The recovery step G of the washing solvent and the extraction solvent is performed in the solvent recovery device 46. The drying step H is performed in the drying device 51. The extension step I is performed in elements 53-64, in particular in heating tubes 56 and 60. However, it will be appreciated that various other parts of the system will also perform some draw lengths, even at temperatures substantially below the temperatures of the heating tubes 56 and 60.
Thus, for example, a slight stretching length (eg, 2: 1) may be applied in the quench bath 30, in the solvent extraction device 37, in the washing device 45, in the drying device 51, and in the solvent extraction device 37 and the drying device 51. Can happen between

Example 2 Gel Spun Spectra (SPECTRA ) Fiber trial
Feed (10.3230 g, about 76% mineral oil) to 50 g of diethylene glycol
50 ml of coal monobutyl ether with periodic stirring
Extracted at <RTIgt; 30 C </ RTI> for 30 minutes. This step was repeated twice or more. Fiber
Water is then added to water at ambient temperature (23-24 ° C)
Rinse) four times and in a vacuum oven at 110 ° C. for 15 minutes
Dried. The weight of the dried fiber was 2.9094 g. In fiber
The residual oil was found to be 0.15% by weight by IR analysis.
Was.

Example 3 Gel Spinning Spectra Fiber sample (9.9768 g, mineral oil about 7
6%) 50 g of diethylene glycol monobutyl ether
Extract at 75 ° C for 30 minutes with periodic stirring
Was. This step was repeated twice or more. Fiber at ambient temperature
Rinse four times with water (23-24 ° C) (15 minutes for each step),
Then, it was dried at 110 ° C. for 15 minutes in a vacuum furnace. Dried fiber
Weighed 2.5338 g. Oil residue in fiber for IR analysis
It was confirmed that the content was 0.43% by weight.

Example 4 Gel Spinning Spectra (Trademark) fiber sample (10.01228
g, mineral oil about 76%) to 50 g of diethylene glycol monobuty
Extract at 100 ° C for 30 minutes with periodic stirring.
Issued. This step was repeated twice or more. Then wrap the fiber
Rinse 4 times in water at ambient temperature (23-24 ° C) (15 minutes for each step)
And dried in a vacuum oven at 110 ° C. for 15 minutes. Dry
The weight of the fiber was 2.4337 g. Residual oil in fiber is IR content
It was confirmed by analysis that the content was 0.00% by weight.

Extractions were performed on polyether solvents at various temperatures using the procedures of Examples 2-4. The residual mineral oil was quantified by IR analysis. The results and process parameters (ie, solvent temperature) are shown in Table 1 below.

Example 5 The figure illustrates, in schematic form, one embodiment of the present invention, at least 500,000, and often at least 75
Shown is a first mixing vessel 10 supplied with an ultra-high molecular weight polymer 11 such as polyethylene having a weight average molecular weight of 0,000 and also supplied with mineral oil via a supply line 12 patrol. The first mixing container 10 has a stirrer 13. The residence time of the polyethylene and mineral oil in the first mixing vessel 10 is sufficient to produce a slurry containing some dissolved polyethylene and some relatively finely ground polyethylene particles.
The polyethylene / mineral oil slurry is removed via line 14 to a strong mixing vessel 15. The powerful mixing vessel 15 has a spiral stirring blade
Has 16 The residence time in the intense mixing vessel 15 and its agitation rate are sufficient to convert the polyethylene / mineral oil slurry to a solution. The temperature in the intense mixing vessel 15 may depend on the external heating, the heating of the polyethylene / mineral oil slurry 14, the heat generated by the intense mixing, or any combination of the above, to convert the polyethylene to the desired concentration in mineral oil (generally relative to the solution). It will be appreciated that it is sufficiently high (e.g., 200 <0> C) to completely dissolve (5-10% by weight polyethylene). From an intense mixing vessel 15, the solution is extruded with a barrel 19 with a screw 20 driven by a motor 22 to send the polyethylene solution at a moderately high pressure to a gear pump and housing 23 at a controlled flow rate. Supplied to 18. The motor 24 drives the gear pump 23 and may be circular, X-shaped or oval, or of various shapes having a relatively small major axis in the plane of the spinneret when it is desired to form fibers. A still hot polyethylene solution through a spinneret 25 containing a plurality of spinholes, which can have a rectangular or other shape with a long major axis in the plane of the spinneret, if desired, or to form a film It is provided to extrude. Mixing container 15
Medium, the temperature of the solution in the extruder 18 and in the spinneret 25 are all selected to exceed the gelation temperature for polyethylene in mineral oil (approximately about 100-130 ° C.).
(For example, 200 ° C.) or higher.

The temperature may vary from the mixing vessel 15 to the extruder 18 to the spinneret 25 (eg, about 220 ° C., about 210 ° C.).
° C and about 220 ° C) or may be constant (eg, about 220 ° C). However, in all respects,
Preferably, the concentration of polyethylene in the solution is substantially the same. The number of spinholes, and thus the number of fibers formed, is not critical, and a convenient number of spinholes is 16, 12
0, 240.

The polyethylene solution exiting the spinneret 25 may be filled, optionally surrounded by an inert gas such as nitrogen, and optionally supplied with a gas stream to facilitate cooling. Good, passing through the air gap 27. A plurality of gel fibers 28 containing mineral oil pass through an air gap 27 and enter a quench bath 30 containing any of a variety of liquids, where a polyethylene / mineral oil system is used in both the air gap 27 and the quench bath 30. The fibers are cooled to a second temperature at which the solubility of the polyethylene in the mineral oil is relatively low so as to solidify to form a gel. The quenching liquid in the quench bath 30 is preferably water. Some stretching is allowed in the air gap 27, but is preferably less than about 10: 1.

Rollers 31 and 32 in quench bath 30 operate to feed fibers through the quench bath, preferably with little or no stretching. Slight stretching on rollers 31 and 32
Some mineral oil seeps out of the fiber when it occurs across the fiber, which can be collected as the top layer in the quench bath 30.

From the quench bath 30, the cold first gel fibers 33 proceed to a solvent extraction unit 37 in which a second extraction solvent is supplied through line 38 and is maintained at a certain temperature in the unit 37. The second extraction solvent is a solvent for the mineral oil of the first spinning solvent but is a polyether solvent. The second extraction solvent is also a solvent for water but non-solvent for polyethylene. The second extraction solvent is preferably a monoalkyl or alkyl ether of a polyalkylene glycol such as diethylene glycol modiethylene ether.
The second extraction solvent extracts a mineral oil spinning solvent from the gel fiber,
Fibrous structures containing up to about 15.0% by weight mineral oil based on the weight of the fiber, and more preferably up to about 1.5% by weight mineral oil based on the weight of the fiber; and a first spin solvent of the mineral oil and a polyether. A first solution comprising two extraction solvents is formed. The solution is conveyed by a solvent effluent line 41 to a solvent separator 41 where the solution is extracted with a third extraction solvent, preferably water, and a first phase consisting of two liquid phases, the spinning solvent (the spinning solvent is the first solvent). At least about 80%, preferably at least about 90%, more preferably at least about 95% and most preferably about 99% by weight based on the weight of one phase), and
To form a heterogeneous liquid mixture consisting of a second phase consisting of a solution of the third extraction solvent. These immiscible phases are separated and the spinning solvent phase is mixed by lines 42 and 11 in the mixer.
Carried to 11. The second phase is conveyed via line 49 to the extraction solvent recovery unit 46, where the second and third extraction solvents are, for example, the second extraction solvent is diethylene glycol ethyl ether and the third extraction solvent is water. In some cases, the separation is effected by any suitable method, such as, for example, temperature-induced phase separation. The separated second extraction solvent is conveyed to the solvent extraction device 37 via lines 43 and 38, while the third extraction solvent is conveyed to the solvent extraction device 41 via line 49 (a). The fibrous structure 44 derived from the solvent extraction device 37 contains substantially only the extraction solvent and a relatively small amount of mineral oil. The fibrous structure 44 will be slightly shrunk compared to the first gel fiber 33. The fibrous structure 44 is then conveyed to a washing chamber 45, where the fibrous structure 44 containing the second extraction solvent is washed with a washing solvent (such as a third extraction solvent) in which the second extraction solvent is soluble. The second extraction solvent is removed from the product 44. The washing solvent preferably has a volatility less than that of the extraction solvent (boiling point below about 100 ° C.). Preferably, the washing solvent is a low molecular weight alcohol such as methanol and ethanol, and water. In a preferred embodiment of the present invention, the washing solvent is the same liquid as the third extraction solvent. The most preferred washing solvent is water.

Structure 44 removes from structure 44 up to about 5%, preferably up to about 1%, more preferably up to about 0.2% by weight of the second extraction solvent (based on the concentration of that of the second extraction solvent). Washed for a sufficient time and degree. In a preferred embodiment, since the washing solvent and the second extraction solvent are the same, the solution of the washing solvent and the third extraction solvent is conveyed via line 47 to a solvent recovery unit 46 where the washing solvent and the extraction solvent are separated. You. After washing, the mixture of the washing solvent and the second extraction solvent is removed until the concentration of the second extraction solvent in the washing solvent becomes too high to effectively remove the second extraction solvent from the structure 44, for example. It can be recirculated one or more times to the working chamber 45 by any convenient means, such as a conduit (not shown), and then conveyed to the unit 46.
However, in such an embodiment of the invention where the washing solvent and the third extraction solvent are different, the solution is conveyed to a washing solvent / second extraction solvent separation chamber (not shown) where the solvent is separated. The washing solvent is conveyed to the washing chamber 45 and the second extraction solvent is conveyed to the device 37 by some suitable means, such as for example by a line (not shown).

The washed fibrous structure 50 is conveyed to the drying device 51. In the drying device 51, the washing solvent is evaporated from the fibrous structure 50, forming essentially undrawn xerogel fibers 52 and taken up by the spool 53.

If it is desired to operate the draw system at a slower feed rate than withdrawal of the spool 53 is allowed,
From 53 or from a plurality of such spools, the fiber is fed over a driven feed roll 54 and idler roll 55 into a first heating tube 56. Enough heat pipe
56 to bring the fiber temperature from about 120 to about 140 ° C.
The fibers are drawn at a relatively high draw ratio (eg, 5: 1) to form partially drawn fibers 57 that are taken up by drive roll 58 and play roll 59. Rolls 58 and 59
From there, the fibers are drawn through a second heating tube 60, heated to a somewhat higher temperature, e.g., about 130 to about 160C, and in the heating tube 60 as desired, e.g., 1.8. :
It is taken up by a drive take-up roll 61 and a play roll 62 which are operated at a speed sufficient to give a stretching ratio of 1. The twice-drawn fiber 63 produced in the first embodiment is taken up by a take-up spool 64.

For the ten process steps of this preferred embodiment of the invention described in this example, it can be seen that solution formation step A is performed in mixers 13 and 15. Extrusion process B
Is carried out by the devices 18 and 23, in particular through the spinneret 25. The cooling step C is performed in the air gap 27 and the quench bath 30. The extraction step D is performed in the solvent extraction device 37. The separation step E between the extraction solvent and the spinning solvent is performed in the separator 41. The separation step F of the second and third extraction solvents is performed in the apparatus 46.
It takes place inside. The fiber cleaning step G is performed in the cleaning chamber 45. The washing solvent and extraction solvent recovery step H is performed in the apparatus 46 in this preferred embodiment where the washing solvent and the third extraction solvent are the same. The drying step I is performed in the drying device 51. The stretching step J is performed in the elements 53 to 64, in particular, in the heating tube 56.
And in 60. However, it will be appreciated that various other parts of the system can also perform some elongation, even at temperatures substantially below the temperatures of the heating tubes 56 and 60. For example, a slight stretching (eg, 2: 1) may be performed in the quench bath 30, in the solvent extraction device 37,
In the washing device 45, in the drying device 51, and in the solvent extraction device 37.
And drying device 51 can occur.

Example 6 Gel Spinning Spectra Fiber sample (10.2211 g, mineral oil approx.
76%) with 50 g of diethyl carbitol
While extracting at 50 ° C. for 30 minutes. Repeat this process twice
The above was repeated. The fiber then in water at ambient temperature (23-24 ° C)
(Four minutes for each step) 4 times, and in a vacuum furnace,
Dry at 110 ° C. for 15 minutes. The weight of dried fiber is 2.4572g
there were. The residual oil in the fiber was 0.3% by weight by infrared analysis.
It was confirmed that there was.

Example 7 Gel Spinning Spectra Fiber sample (10.4084g, mineral oil approx.
76%) each with 50 g of diethyl carbitol
Extracted at warm for 30 minutes. The fiber is washed four times with water at ambient temperature
Rinse the phases for 15 minutes. The fiber is then placed in a vacuum furnace,
Dry at 110 ° C. for 15 minutes. The dry fiber weight is 2.5091g
there were. The residual oil remaining in the fiber was 0.8
% By weight.

────────────────────────────────────────────────── ─── Continuing the front page (72) Inventor Bellemborne, Morris Be, New Jersey, USA 07901, Summit, Crest Drive 59 (72) Inventor, Litt, Morton H. 44118, Ohio, United States, University Heights, Charney・ Load 2575 (72) Inventor Hacker, Scott M. New York, USA 10023, New York, West End Avenue 150, No. 9A (72) Inventor Bose, Anjana, New Jersey, USA 07896, Randolph, West Hanow Bar Avenue 122 (56) References JP-A-64-68512 (JP, A) JP-A-58-5228 (JP, A) (58) Fields studied (Int. Cl. ⁷⁾ , DB name) D01F 13/04 D01F 6/04

Claims (10)

(57) [Claims] 1. A method for extracting a first spinning solvent from a solution spun fiber comprising the steps of: (a) continual length fibers containing a first spinning solvent are sufficiently sunk with a second extraction solvent. For a contact time that is substantially the same as that of the first spinning solvent and the second extraction solvent and the second solvent, but not containing or substantially not containing the first solvent. Forming an infinite length of fiber; wherein the second extraction solvent is: (i) the first spinning solvent is soluble or substantially soluble at a _first temperature T ₁ , and second at the temperature T ₂ is as or substantially insoluble insoluble, therefore the second extraction solvent first temperature T ₁ of in the first spinning solvent by extracting the first spinning solvent from the fibers And a first solution consisting of said second extraction solvent and When the first solution is subjected to the second temperature T ₂ , two different liquid phases, a first liquid phase mainly consisting of the first spinning solvent and a second liquid phase mainly consisting of the second extraction solvent, A second extraction solvent forming a first heterogeneous mixture consisting of a liquid phase; and (ii) the first spinning solvent is soluble or substantially soluble, and the first spinning solvent is A second extraction solvent that is soluble or substantially soluble in a third extraction solvent that is immiscible with the second extraction solvent in the first spinning solvent and in the third extraction solvent. Relative solubility in a solvent, wherein the third extraction solvent partially or wholly extracts the second extraction solvent from a second solution comprising the second extraction solvent and the spinning solvent; That is, the third liquid phase mainly composed of the first spinning solvent, the second extraction solvent mainly and the third extraction solvent A second heterogeneous liquid mixture consisting of a fourth liquid phase consisting of a solvent, selected from the group consisting of the second extraction solvent; and (b) the first solution is a mixture of the first heterogeneous liquid. Subjecting the second solution to the second temperature T ₂ for a time sufficient to form a mixture, or
Separating the first solution or the second solution into the first and second liquid phases by extracting for a time sufficient to form a heterogeneous liquid mixture; and (c) the second liquid. Recycling the phase or the fourth liquid phase to the extraction step. 2. A step of forming a spinning solution of a polymer having a fiber-forming molecular weight and a spinning solvent; the spinning temperature is higher than the gelation temperature at which a rubbery gel is formed upstream of the spinning hole; Extruding a spinning solution substantially at a first concentration from the spinning hole both upstream and downstream of the hole; a gel adjacent to the spinning hole and downstream of the spinning solution where a rubbery gel is formed at a lower temperature. Cooling to the formation temperature to form a substantially infinite length of solvent-containing gel;
Extracting the first solvent-containing gel with a second volatile solvent for a sufficient contact time to form a substantially infinite length second solvent-containing fibrous structure wherein the gel is substantially free of the first solvent; Drying the second solvent-containing fibrous structure to form a substantially infinite length xerogel free of the first and second solvents; and the first solvent-containing gel, the second At least one of a solvent-containing fibrous structure and a xerogel
An improved method of solution spinning a polymer fiber comprising two stretching steps, the improvement comprising the following steps: (a) continuous length fibers containing a first spinning solvent. Is extracted with a second extraction solvent for a sufficient contact time, and contains a solution of the extracted first spinning solvent, the second extraction solvent, and the second extraction solvent, but does not contain or substantially contains the first solvent. Forming a fiber of substantially infinite length, wherein the second extraction solvent comprises: (i) the first spinning solvent is soluble at a _first temperature T ₁ or substantially variable, and a certain or substantially insoluble in the second insoluble at temperatures T _2, the order that second
Extraction solvent can form a first solution consisting of the second extraction solvent and the first spinning solvent by extracting the first spinning solvent from the fibers at the first temperature T _1, thus also the second When one solution is subjected to the second temperature T ₂ , two different liquid phases, a first liquid phase mainly consisting of the first spinning solvent and a second liquid phase mainly consisting of the second extraction solvent, The first consisting of
A second extraction solvent, which forms a heterogeneous mixture of: (ii) said first spin solvent is soluble or substantially soluble, and is immiscible in said first spin solvent. A second extraction solvent that is soluble or substantially soluble in a third extraction solvent, wherein the second extraction solvent is relatively soluble in the first spinning solvent and in the third extraction solvent. The solubility is such that the third extraction solvent partially or totally extracts the second extraction solvent from a second solution consisting of the second extraction solvent and the spinning solvent, so that two different liquid phases, namely the second The second extraction solvent forming a second heterogeneous liquid mixture consisting of a third liquid phase composed of one spinning solvent and a fourth liquid phase mainly composed of the second extraction solvent and the third extraction solvent. (B) mixing the first solution with the first solution; Extracting the second solution with the third extraction solvent for a time sufficient to form the second heterogeneous liquid mixture by subjecting the second solution to the second temperature T ₂ for a time sufficient to form a homogeneous mixture. (C) separating the first solution or the second solution into the first and second liquid phases, and (c) separating the second liquid phase or the fourth liquid phase into the extraction step. Recirculation process. 3. The fiber of claim 2 wherein said fiber is a polyethylene fiber having a molecular weight equal to or greater than about 500,000.
The described method. 4. The method according to claim 3, wherein said first spinning solvent is a hydrocarbon and said second extraction solvent is a polyether solvent. 5. The method according to claim 4, wherein said spinning solvent is a mineral oil. 6. The polyether of the following formula: R (OCH ₂ CH ₂ ) _x OR ¹ and R (OCH ₂ CH (CH ₃ ) _x OR ^{1 wherein} x is an integer from 1 to about 8 And R and R ¹ are the same or different and are hydrogen or alkyl having about 1 to about 4 carbon atoms.) Mono- and dialkyl ethers of polyalkylene glycols selected from the group consisting of polyethylene glycol ethers and polypropylene glycol ethers 6. The method of claim 5, wherein: 7. The following: (a) said fibers containing said first spinning solvent and said second spinning solvent;
At the first temperature T ₁ ,
The fiber is contacted for a time sufficient to extract some or all of the spinning solvent from the fibers to provide an infinite length of fibers containing the second solvent and the extracted first spinning solvent. Forming a solution in the second extraction solvent, provided that
The second extraction solvent is such that the first spinning solvent is at the first temperature.
In T ₁ is the second extraction or substantially soluble in a solvent which is soluble, and if it is insoluble in the second extraction solvent in the second temperature T ₂ or to be a substantially insoluble chosen, (b) separating the fibers from the solution, (c) said given the solution of the spinning solvent and the polyether extraction solvent to the second temperature T _2, 2 two different liquid to Forming a heterogeneous liquid mixture consisting of a phase, i.e., a first liquid phase consisting mainly of said first spinning solvent and a second liquid phase consisting mainly of said second polyether extraction solvent; (d) The method of claim 6, comprising the steps of: separating a first and second liquid phase; and (e) recycling the second liquid phase to the contacting step (a). 8. The method according to claim 7, wherein said mono and dialkyl ethers of polyalkylene glycol are selected from the group consisting of tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether and diethylene glycol monopropyl ether. 9. The following: (a) a continuous length of fiber containing a first spinning solvent is treated with a polyether-based second extracting solvent, the first spinning solvent containing the second extracting solvent, and Extracting for a time sufficient to form a fibrous structure free or substantially free of the extracted first spin solvent and the second extraction solvent, wherein the second extraction solvent comprises: The first spinning solvent is soluble or substantially soluble in the second extraction solvent and is soluble in a third extraction solvent that is immiscible with the spinning solvent; The relative solubility of the solvent in the spinning solvent and in the third extraction solvent is such that the third extraction solvent removes part or all of the second extraction solvent from the second solution and the first solution of the spinning solvent. So that they can be extracted (B) combining the first solution with the third extraction solvent in two different liquid phases, ie, a first liquid phase mainly consisting of the first spinning solvent, and mainly the second extraction solvent and the third extraction solvent. Extracting for a time sufficient to produce a heterogeneous liquid mixture consisting of a second liquid phase consisting of a second solution comprising an extraction solvent; (c) the first and second of step (b). Separating the phases,
And (d) separating the second extraction solvent from the third extraction solvent, and recycling the second extraction solvent to the extraction step (a) and recycling the third extraction solvent to the extraction step (b). 7. The method according to claim 6, comprising: 10. The improvement of claim 9 wherein said second extraction solvent is selected from the group consisting of dimethylethylene glycol and diethyldiethylene glycol, and wherein said third extraction solvent is water or an alcohol having 1 to 4 fatty acid carbon atoms. Way.