JPH0357963B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is a gel yarn spinning method for obtaining fibers and films with high strength and high modulus (high modulus of elasticity) that could not be obtained by conventional melt spinning, dry spinning, or wet spinning. In the method and gel film forming method, a new method for preparing spinning solutions and film forming solutions for gel yarn spinning and gel film forming, and long-term operation stability and high productivity of the gel yarn spinning and gel film forming method. Regarding how to achieve.

Synthetic polymers generally undergo inherent discoloration or decomposition before melting when exposed to high temperatures, so from this perspective melt spinning pure synthetic polymers into fibers and films is an inherently preferable method. No, no. Also among synthetic polymers are synthetic polymers such as polyvinyl alcohol, which can never be melt-spun as an essentially pure polymer, or polyacrylonitrile, and which cannot be melt-spun without undergoing substantial degradation. Examples include ultra-high molecular weight materials such as polyethylene, polypropylene, polyester, and nylon. Such synthetic polymers can be processed into fibers or films with the aid of suitable low molecular weight compounds.
That is, the synthetic polymer is plasticized or dissolved by the low molecular weight compound, and therefore can be processed at a temperature below the decomposition point of the synthetic polymer. Such synthetic polymers can be made into fibers or films by a number of conventional methods using solvents to lower the softening point of the synthetic polymer.

A gel yarn spinning method is suitable as a method for obtaining high strength and high elastic modulus fibers. However, when the gel yarn spinning method is spun using equipment similar to that used in melt spinning, the greatest difficulty lies in the difficulty of preparing a uniform spinning solution of the required concentration. That is, for this purpose, the synthetic polymer and the solvent generally have to be milled at a temperature close to the decomposition temperature of the synthetic polymer and mixed with stirring for a long period of time. Even if this is done, it is often not possible to achieve a sufficient uniform dissolution of the synthetic polymer in the solvent. In particular, in order to obtain high-strength, high-modulus fibers, ultra-high molecular weight synthetic polymers are required, and in this case, the dispersion and dissolution of the synthetic polymer in the solvent becomes even more uneven, The viscosity of the solution becomes viscous, and the inclusion of air bubbles during the stirring and mixing process is unavoidable. Agglomerates of undissolved molecules, inclusion of air bubbles, non-uniformity of the solution, etc. lead to unstable spinning in the spinning process, and in some cases, to the impossibility of yarn spinning. Moreover, the quality of the final fiber obtained is also poor.

Conventional technology to solve these shortcomings involves installing multiple melting tanks in the melt-spinning process, using primary melting, secondary melting, strong stirring, and long melting times to ensure uniform dissolution. There is a method of spinning by supplying the material to a screw type extruder while keeping it warm at a high temperature. Although this dissolution method can obtain a somewhat uniform solution, it takes a long time to dissolve, and in particular, ultra-high molecular weight synthetic polymers are required to obtain fibers with high strength, high elastic modulus, and high toughness. However, in the case of ultra-high molecular weight polymers, dissolution at high temperatures and for a long period of time is required, which leads to a significant decrease in the molecular weight of the synthesized polymer. Furthermore, since the dissolution tank method uses powerful stirring to ensure uniform dissolution, the incorporation of fine air bubbles into the solution is unavoidable. As described above, the dissolution tank method has many disadvantages, such as the need to install multiple dissolution tanks, the long time it takes to dissolve, the significant decrease in the molecular weight of the synthetic polymer, and the tendency for air bubbles to get mixed in. be. Furthermore, when a solution obtained by such a conventional method is supplied to a spinning process, stable spinning cannot be performed for a long time, and the quality of the obtained fibers is also poor, which is insufficient for industrial production.

The present inventors have developed a high-strength, high-modulus fiber or film using a gel yarn spinning method or a gel film forming method, which is industrially advantageous, has good long-term operation stability, and has high productivity. As a result of intensive research and study into methods of manufacturing products in extremely superior quality, we have finally achieved the present invention, which achieves the intended purpose.

That is, the gist of the present invention is to produce gel fibers or gel films from a solution of a crystalline synthetic polymer,
Next, in a method for producing a high-strength, high-modulus fiber or film by stretching the gel-like fiber or gel-like film at a high magnification, the crystalline synthetic polymer is once dissolved in a solvent and then cooled to occlude the solvent. The gel granules are then dispersed or dissolved in the same or different solvent as the solvent occluded in the gel granules and supplied to a gel fiber spinning process or a gel film forming process. This is a method for producing a high strength, high modulus fiber or film.

A crystalline synthetic polymer is dissolved in an appropriate solvent under heating to form a solution, the solution is supplied to a spinning process or a film forming process, and after spinning or extrusion, it is cooled to produce a gel-like fiber containing a large amount of solvent. or a gel-like film, and then the gel-like fibers or gel-like film are stretched at a high magnification to produce high-strength, high-modulus fibers or films (herein, for simplicity, the gel yarn spinning method is used) (also sometimes abbreviated as gel film molding method) is, for example, disclosed in JP-A-Sho
It is known from JP-A-55-107506, JP-A-56-15408, JP-A-58-5228, and JP-A-58-81612.

The present invention provides a unique method for preparing a spinning solution and a film forming solution to be supplied to the spinning process or film forming process in the gel yarn spinning method or gel film forming method. Once the polymer is dissolved in a solvent, it is cooled to form gel particles that occlude the solvent, and then the gel particles are dissolved in a solvent that is the same as or different from the solvent occluded in the gel particles (these solvents are It is a solvent for preparing a polymer solution supplied to a spinning process or a film forming process) and is uniformly dispersed or dissolved therein and then supplied to a spinning process or a film forming process.

Next, the method for producing gel granules that occlude a solvent according to the present invention will be explained in detail. First, as a solvent for producing gel granules, a crystalline synthetic polymer (herein, for simplicity, it may be simply referred to as synthetic polymer) for gel yarn spinning or gel film forming is used. A single low molecular weight compound or a mixture of low molecular weight compounds that dissolve only at elevated temperatures is used. However, the heating temperature must be lower than the decomposition temperature of the synthetic polymer. And at low temperatures, for example room temperature, this low molecular weight compound or mixture thereof must be a non-solvent for the polymer.

The fine powder of the synthetic polymer is added to the solvent in an appropriate weight proportion, preferably in a proportion that is approximately the same concentration as the synthetic polymer concentration in the gel yarn spinning solution or gel film forming solution (usually the synthetic polymer concentration is Approximately 1
The synthetic polymer is added at a concentration of ~10% by weight), heated to a temperature at which the polymer does not deteriorate, and stirred and mixed using a stirrer such as a homomixer. dissolve. In this case, the solution becomes viscous as the synthetic polymer dissolves. For example, if the synthetic polymer is polyethylene powder with an ultra-high molecular weight (e.g., weight average molecular weight of about 1 x 10 ⁶ or more) and if, for example, decalin is used as the solvent, the temperature will increase from room temperature to about 160°C for about 1 hour. Raise the temperature while stirring, and stir slowly at 160°C for about 1 hour to dissolve. In this way, when preparing the gel particles of the present invention, it is not necessary to take a long time to dissolve the synthetic polymer. It is rather undesirable to carry out this stirring and dissolution at high temperatures for a long period of time, as this will lead to a decrease in the molecular weight of the synthetic polymer.

A particularly important point in preparing the gel granules that occlude a solvent in the present invention lies in the cooling conditions of the thus dissolved solution. It is important to perform this cooling slowly and gradually as much as possible. This cooling produces fine gel particles that occlude the solvent, but in this case, if the cooling is not done slowly but rapidly,
This results in a film-like or rice cake-like coarse gel-like material, and it is not possible to obtain gel particles with a microscopic particle size having an average particle size of 1 mm or less. In addition, when producing a uniform spinning solution for gel yarn spinning or a uniform solution for gel film forming at a predetermined concentration, the film-like or mochi-like coarse gelatinous material does not dissolve uniformly in the spinning solution or the solvent for preparing the film forming solution. This causes yarn breakage in the gel yarn spinning process and drawing process, causes film breakage in the gel film forming process, and causes uneven quality of product yarns and films.
When this solution is slowly cooled, the formation of the above-mentioned film-like or mochi-like coarse gel is suppressed, and most of the gel particles have an average particle size of 1 mm or less and absorb the solvent. Become. However, the present inventors have discovered that such gel particles having an average particle diameter of 1 mm or less can be easily and uniformly dissolved in a spinning solution for gel yarn spinning or a solvent for preparing a gel film forming solution. That is, such gel particles having an average particle diameter of 1 mm or less are added to, for example, a solvent for preparing a gel yarn spinning solution to a predetermined synthetic polymer concentration, and stirred using an appropriate stirrer such as a homomixer. to form a uniform dispersion liquid, and supply the dispersion liquid into an extruder hopper of a gel yarn spinning apparatus equipped with an extruder type extruder at a temperature below the deterioration temperature of the gel granules, preferably at room temperature. The gel granules are heated and dissolved in a ruder, discharged from a spinneret, and the discharged yarn is cooled immediately below the spinneret with an appropriate cooling medium (for example, cooling gas or cooling liquid) while containing the solvent. By forming a gel yarn and then directly winding it, or by stretching it at least one step before winding and then winding it, extremely stable spinning can be achieved continuously for a long period of time without causing yarn breakage. Gel yarn can be spun based on operability.

However, when preparing the gel particles described above, slow cooling can be carried out by, for example, leaving the solution after dissolving at high temperature at room temperature for about a day or night. However, even if it is not left to cool naturally like this,
It is possible to obtain gel granules with an average particle size of 1 mm or less. An example of this method is to perform slow cooling in stages. That is, this is a method in which the high-temperature solution of the synthetic polymer is held under two or more multistage cooling temperature conditions set at a temperature lower than the temperature of the solution for an appropriate period of time, and then slowly cooled in multiple stages. According to this method, it is possible to obtain the desired desired fine gel particles in a shorter time than in the case of slow cooling by natural cooling.

The gel particles in the present invention are a mixture of a monocytic gel that occludes a solvent and a composite spherulite gel in which two or more monocytic gels are aggregated and firmly bonded together. The slow cooling is effective as a means of increasing the proportion of monocytic gel in the gel particles. Therefore, in order to prepare a spinning solution for gel yarn spinning or a molding solution for gel film molding extremely easily and in a short time, it is desirable to have as large a proportion of monocytic gel as possible in the gel granules. It is preferable that the monocrystalline gel accounts for 50% or more, preferably 70% or more of the total weight.

Furthermore, the present inventors have also discovered that there is a size of monocytic crystal gel that has extremely good solubility in solvents for gel yarn spinning or gel film molding.
The average spherulite diameter of monocytic gel is 10 to 200 μm, especially
50-100 μm has been found to be suitable for this purpose. Here, the spherulite diameter can be observed using a normal optical microscope. The average spherulite diameter of the monocytic gel is determined as the average spherulite diameter calculated from n≧50 spherulite gels randomly sampled.

In addition, as mentioned above, it is preferable that the proportion of composite spherulite gel mixed in the monospherulite gel be as small as possible from the viewpoint of solubility in the solvent. Spherulite gel has excellent solubility next to monospherite gel, so
The presence of such composite spherulite gel does not affect solubility in any way. However, since a composite spherulite gel in which more than 20 monospherulite gels are aggregated has poor solubility in a solvent, contamination of such a composite spherulite gel is not preferable, and it is preferable to remove it as appropriate. In the present invention, monocytic crystal gel can be easily determined because it shows a Maltese cross of monocytic crystals when observed with a normal polarizing microscope.

As described above, the method of supplying the gel granules to the gel yarn spinning process or gel film forming process in the present invention is as follows: The mixture is stirred with a homomixer or the like to form a uniform dispersion, and then introduced into the raw material supply extruder hopper of a spinning machine or the extruder hopper of a film molding machine, and the gel granules are mixed in the extruder. Although the method of homogeneous dissolution is the easiest and most economical method to handle, the present invention is not limited to such a method. In the dissolution tank where a large amount is stored,
The gel particles may be added to a predetermined polymer concentration, heated and stirred to form a homogeneous solution, and this may be supplied to a gel yarn spinning process or a gel film forming process while being kept warm. In this case, the dissolution in the dissolution tank has extremely excellent solubility of the gel particles, so that uniform dissolution can be achieved in a much shorter time than in the conventional method.

In the present invention, the solvent for dissolving the gel particles is
It is preferable that the solvent is the same as the solvent occluded in the gel granules, but it is of course possible to use a different solvent. Alternatively, any solvent may be used as long as it can be used as a solvent for gel film molding solutions. Such solvents vary depending on the type of synthetic polymer to be dissolved in the solvent, but for example, when the synthetic polymer is polyolefin such as polyethylene or polypropylene, solvents such as octene, nonane,
aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons with a boiling point of at least 100°C or higher, such as decane, undecane, dodecane, or isomers thereof, and higher straight-chain hydrocarbons or higher branched hydrocarbons; Petroleum fractions with a boiling point of 100℃ or higher, toluene, xylene,
Examples include naphthalene, tetralin and decalin, but halogenated hydrocarbons and other solvents can also be used. Of course, these solvents can also be used as a solvent when preparing the gel particles. When the synthetic polymer is polyacrylonitrile, solvents such as dimethyl formamide and dimethyl sulfoxide can be used.

In the present invention, the best synthetic polymer concentration in the spinning solution or film forming solution must be established by trial and error. This essentially depends on three parameters: the interaction of the synthetic polymer solvent, the molecular weight of the synthetic polymer and the spinning temperature. The better the solvent for a particular synthetic polymer, the higher the optimum spinning concentration. The higher the molecular weight of the synthetic polymer, the lower the optimum spinning concentration. The spinning temperature in the method of the present invention is usually limited by the upper limit by the decomposition temperature of the synthetic polymer or the boiling point of the solvent, and the lower limit by the phase separation or gelation temperature of the spinning solution. Thus, when the synthetic polymer is ultra-high molecular weight polyethylene, the concentration of the synthetic polymer is about 1 to 15% by weight, preferably 2 to 8% by weight, and more preferably 2 to 5% by weight.

In the present invention, the temperature below which the gel particles do not deteriorate means that the gel particles partially dissolve and aggregate in the dispersion containing the gel particles, and the uniform dispersion becomes essentially a non-uniform dispersion. This refers to the temperature below which In the present invention, it is preferable that the gel yarn or gel film containing a large amount of solvent, which is formed by gel yarn spinning or gel film molding, be stretched at least once before being wound up in the spinning process or film forming process, and then wound up. . This stretching is preferably carried out using a hot plate or the like at a stretching ratio of at least 2 times or more, preferably 3 to 20 times. This stretching removes a considerable amount of the solvent contained in the gel thread or gel film. Normally, gel yarn or gel film immediately after spinning or film forming uses a solvent of about 90%
However, due to the stretching in the spinning process, the solvent content is 60% by weight or less, preferably 60% by weight or more.
It is preferable that the content be 50% by weight or less. In this case, the solvent is partially evaporated and partially squeezed out in liquid form. In this way, once stretched and wound in the spinning process or film forming process, the yarn or film will not adhere to each other when the wound yarn or film is rewound and used in the next process. , the unwinding property is extremely good. If the gel yarn or gel film is wound immediately without stretching in this spinning process or film forming process, some of the wound gel yarn or gel film will adhere to each other, making it difficult to unwind in the next process, resulting in yarn breakage during unwinding. There is a disadvantage that the frequency of film breakage increases. When the gel yarn or gel film is stretched at least once (one stage) in the spinning process or the film forming process, the structure of the gel yarn or gel film is stabilized, thereby making it possible to wind it up for a long time. The gel yarn or gel film thus obtained can be made into a high strength, high modulus fiber or film by further stretching in the next step.

The crystalline synthetic polymer in the present invention may be any synthetic polymer that can be spun into gel yarn or formed into a gel film, such as polyethylene, polypropylene, ethylene-propylene copolymer, polyoxymethylene, polyethylene oxide, etc. Examples include various polyesters such as polyolefin, polyacrylonitrile, poly(vinylidene fluoride), polyvinyl alcohol, various polyamides, polyethylene terephthalate, and polybutylene terephthalate. Further, as for the molecular weight of these synthetic polymers, the higher the molecular weight, the more preferable it is from the viewpoint of high strength and high modulus, and it is usually preferable that the weight average molecular weight is 1×10 ⁵ or more.
In particular, in the case of polyethylene, polypropylene and polyacrylonitrile polymers, 1×10 ⁵
Since it is possible to increase the molecular weight to 1×10 ⁶ or higher, it is particularly preferable to use such an ultra-high molecular weight synthetic polymer in the present invention.

According to the present invention, it is possible to prepare a uniform spinning solution and a uniform film forming solution for gel yarn spinning and gel film forming by an extremely simple method without reducing the molecular weight of the synthetic polymer, In addition, gel yarn spinning and gel film forming can be performed with good long-term operation stability, and there is almost no yarn breakage or film breakage in the spinning process, film forming process, or stretching process, resulting in improved productivity. This method is revolutionary as an industrial manufacturing technology for gel yarn spinning and gel film molding, as it has high yield and excellent product quality. In particular, the fact that a synthetic polymer liquid for spinning or film forming can be fed to an extruder at room temperature without heating is extremely advantageous in terms of handling and equipment costs.

Next, examples of the present invention will be shown, but the present invention is not limited to these examples.

Example 1 Fine powder of ultra-high molecular weight polyethylene having a weight average molecular weight of 2×10 ⁶ was added to decalin so that the concentration of the polyethylene was 3% by weight,
The system was stirred for 40 minutes at a stirring speed of 60 rpm.
The temperature was raised to 160℃. At this time, the viscosity of the system rapidly increased from around 120°C due to the dissolution of polyethylene, so the stirring speed of the system was reduced to about 1/10 and stirring was continued at 160°C for 1 hour to create a polyethylene decalin solution. .

Next, the solution thus obtained was allowed to cool down naturally overnight to obtain a gel-like substance. This gel-like material contained some film-like and coarse gel particles with a particle size exceeding 1 mm, but most of the gel was isolated into fine gel particles with an average particle size of 1 mm or less by simple mechanical stirring. I was so excited about what I could do. Next, only the micro gel particles that can be isolated to an average particle size of 1 mm or less were collected and stirred in a homomixer, and the spherical gel was isolated and the spherical gel constituting the gel particles was observed under a microscope.
The monospherulite gel accounted for about 80% by weight of the whole, and the remainder was a composite spherulite gel in which 2 to 10 monospherulite gels were aggregated and bonded. Also, this monocytic gel contains decalin about
It occluded 92% by weight (ie 8% by weight of polyethylene).

Next, the fine gel particles with an average particle size of 1 mm or less that occlude decalin thus obtained were added to decalin as a solvent for preparing the spinning solution so that the polyethylene concentration was 3% by weight, and the mixture was mixed using a homomixer. A homogeneous dispersion of gel particles was prepared by stirring at room temperature.

Next, this homogeneous gel granular dispersion was supplied at room temperature into an extruder hopper of a gel yarn spinning apparatus (approximately the same as a conventional general melt spinning apparatus) equipped with a conventional screw-type extruder.
The extruder temperature used was set at 150°C. A spinneret with 40 single holes with a hole diameter of 0.8 mm and a hole length of 8 mm was used, and the discharge rate of the spinning solution was 46 g/min. The temperature of the spinning head was 156°C, and the temperature of the spinneret surface was 150°C. The discharged yarn is placed directly under the spinneret with room temperature air of 0.4
The gel was sprayed at a speed of m/sec and cooled to obtain a gel thread that still contained decalin. Next, the gel yarn was brought into contact with a vertical slit-shaped hot plate provided below the spinneret and subjected to a first drawing at 110° C. at a draw ratio of 6 times,
After that, I wound it onto a bobbin.

In this way, continuous spinning was carried out for 60 hours, during which time there was no yarn breakage at all, and extremely stable spinning operability was obtained.

Next, the gel thread thus obtained was fed to a drawing process and drawn. The first stretching in the stretching process is carried out by running the gel yarn in contact with a slit-shaped hot plate at 135°C.
It was stretched 4 times at ℃. The thus obtained drawn yarn was again drawn twice at 150° C. while running in contact with the slit-shaped hot plate. That is, drawing was carried out at a total drawing ratio of 48 times in three stages in total, including the first stage drawing following the spinning process. All of the gel yarn obtained by continuous spinning for 60 hours was thus drawn, and the bobbin unwinding property of the gel yarn was good, and there was no drawing yarn breakage during this period, and excellent drawing operability was obtained.

The polyethylene drawn yarn produced in this example had a strength of 46 g/d, an initial modulus of 1400 g/d,
It was a high strength, high modulus fiber with an elongation of 5%.
Further, in the drawn yarn, almost no unevenness in fineness was observed both between single yarns and in the fiber length direction, and almost no decrease in molecular weight was observed with respect to the raw material polyethylene.

Comparative Example 1 The same ultra-high molecular weight polyethylene powder with a weight average molecular weight of 2×10 ⁶ as in Example 1 was subjected to primary dissolution and secondary dissolution over 48 hours under stirring in a nitrogen atmosphere using two dissolution tanks. , polyethylene concentration 3
A solution of % by weight was obtained.

Next, this solution was supplied through a heat-retaining pipe to the extruder hopper of a gel spinning device equipped with the same extruder as in Example 1, and thereafter gel yarn was spun under the same conditions as in Example 1 and wound onto a bobbin. .

In the case of this example, air bubbles were found to be mixed in the solution discharged from the spinneret, and yarn breakage frequently occurred. Further, the viscosity of the discharged solution was also non-uniform.

When the gel yarn obtained in this example was then drawn under the same conditions as in Example 1 to create a polyethylene drawn yarn, yarn breakage occurred frequently during the drawing process, and the drawn yarn obtained was The fineness is uneven in both the longitudinal direction, the strength is 32 g/d, and the initial modulus is 980 g/d.
The physical properties were far inferior to those of Example 1. Furthermore, the molecular weight of the obtained polyethylene fibers was significantly lower than that of the starting material, polyethylene.

Comparative Example 2 When producing a gel from the same polyethylene decalin solution as in Example 1 (temperature: 160°C, polyethylene concentration: 3% by weight), instead of slow cooling as in Example 1, it was forced to room temperature for 30 minutes. A gel-like substance was obtained by cooling. The gel-like material was a sponge-like material that occluded decalin.

Next, the gel-like material thus obtained was stirred vigorously for a long time using a homomixer to crush the gel-like material into small pieces, which were immediately transferred to the extruder hopper of the same gel yarn spinning apparatus as in Example 1. Thereafter, gel yarn was spun under the same conditions as in Example 1.

In this example, the supplied gel was sheared by the screw of the extruder, and the decalin occluded in the gel was squeezed out and flowed back into the extruder hopper inlet. Furthermore, the solution discharged from the spinneret had a high concentration of polyethylene and had a non-uniform solution concentration, making it impossible to wind up the solution.

Example 2 A fine powder of ultra-high molecular weight polyacrylonitrile with a weight average molecular weight of 3 x 10 ⁶ was added to dimethylformamide at a concentration of 7% by weight.
After that, the temperature of the system was raised to 180°C with stirring in the same manner as in Example 1, and the mixture was dissolved at 180°C.

Next, the solution thus obtained was allowed to cool down naturally overnight to obtain a gel-like substance. Although this gel-like material contained some film-like and coarse gel particles with a particle size exceeding 1 mm, most of the gel-like material could be isolated into fine gel particles with an average particle size of 1 mm or less by mechanical stirring.

Next, from this gel-like material, a film shape and a particle size of 1
Coarse gel particles exceeding 1 mm in size were removed, stirred with a homomixer, and only fine gel particles with an average particle size of 1 mm or less were isolated. When the spherical gel constituting the gel particles was observed under a microscope, the average particle size was 50 μm. The monospherulite gel accounted for 75% by weight of the total, and the remainder was a composite spherulite gel in which 2 to 15 monospherulite gels were aggregated and bonded. In addition, this monocytic crystal gel was prepared using dimethylformamide.
It occluded 85% by weight (ie 15% by weight of polyacrylonitrile).

Next, the microgel particles with an average particle size of 1 mm or less that occlude dimethylformamide thus obtained were added to dimethylformamide as a solvent for preparing the spinning solution so that the concentration of polyacrylonitrile was 7% by weight, and the mixture was mixed with a homomixer. A homogeneous dispersion of gel particles was prepared by stirring at room temperature.

Next, this uniform dispersion was fed into the extruder hopper of the same gel yarn spinning apparatus as in Example 1 at room temperature. The extruder temperature used was set at 180°C. Pore size for spinneret
A spindle with four single holes of 0.8 mm and 8 mm in length was used, and the amount of spinning solution discharged was 6 g/min. Also, the temperature of the spinning head is 186℃, and the temperature of the spinneret surface is 180℃.
And so. The discharged yarn was placed several centimeters below the spinneret surface in an alcohol-dry ice system at -40°C.
A gel fiber was produced by discharging the gel into a cooling liquid using an air gap spinning method and cooling it.

The spinning condition in this example was good, and continuous spinning was possible without yarn breakage.

Further, when the obtained gel fiber was drawn at high temperature and at a high magnification according to Example 1, the drawing operability was stable, and an acrylic fiber with high strength and high modulus was obtained.

Claims (1)

[Claims] 1. By producing gel fibers or gel films from a solution of a crystalline synthetic polymer, and then stretching the gel fibers or gel film at a high magnification,
In a method for producing high-strength, high-modulus fibers or films, the crystalline synthetic polymer is once dissolved in a solvent and then cooled to form gel granules that absorb the solvent, and then the gel granules are dissolved in the gel granules. High strength, characterized in that it is dispersed or dissolved in the same or different solvent than the solvent occluded in the gel fiber spinning process or gel film forming process.
A method for producing a high modulus fiber or film. 2 The average particle diameter of the gel particles that absorb the solvent is 1 mm.
High strength according to claim 1 which is as follows,
A method for producing a high modulus fiber or film. 3. The gel particles that occlude the solvent are composed of only a monocytic gel or a mixture of a monocytic gel and a composite spherulite gel, and the average spherulite diameter of the monocytic gel is 10 to 200μ.
m, and the composite spherulite gel has 2 to 2 m of the monospherulite gel.
A method for producing a high strength, high modulus fiber or film according to claim 1 or 2, which is an aggregate of 20 fibers. 4 The gel particles are uniformly dispersed in the same solvent as the solvent occluded in the gel particles to obtain a gel particle dispersion, and the dispersion is processed into gel fibers using an extruder type extruder. The gel granules are fed into an extruder hopper of a manufacturing spinning device or a gel film forming device at a temperature below the deterioration temperature, and the gel granules are heated and melted in the extruder to spin gel fibers. A method for producing a high-strength, high-modulus fiber or film according to claim 1, 2, or 3, which further comprises forming a gel-like film. 5. The method for producing a high-strength, high-modulus fiber or film according to claim 1, wherein at least the first stage of stretching the gel-like fiber or gel-like film is carried out consecutively to a spinning step or a film forming step. 6. Claim No. 6 in which the crystalline synthetic polymer is one or more compounds selected from the group of polyolefins such as polyethylene and polypropylene, polyacrylonitrile, poly(vinylidene fluoride), polyvinyl alcohol, polyamides, and polyesters. A method for producing a high strength, high modulus fiber or film according to item 1. 7 High tenacity, high modulus fiber or film is
Polyethylene type with a weight average molecular weight of 1×10 ⁵ or more,
7. A method for producing a high-strength, high-modulus fiber or film according to any one of claims 1 to 6, which is made of a polypropylene-based or polyacrylonitrile-based polymer. 8. The high strength, high modulus fiber or film according to any one of claims 1 to 7, wherein the high strength, high modulus fiber or film is made of a polyethylene polymer having a weight average molecular weight of 1 x 10 ⁶ or more. manufacturing method.