JP5271026B2 - Method for producing aramid polymer solution, production system, and aramid polymer molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aramid polymer solution, by which the aramid polymer can quickly be dissolved in a solvent. <P>SOLUTION: There is provided the method for producing the aramid polymer solution, characterized by dissolving the solid aramid polymer dispersed in the solvent in a thin film state with a thin film rotation mixer having a function exposed to a strong shear field. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing an aramid polymer solution, and more particularly, to a method for producing an aramid polymer solution by dissolving an aramid polymer in a solvent using a thin film swirl mixer.

  Aramid polymer consisting of aromatic dicarboxylic acid component and aromatic diamine component, taking advantage of its high strength, high elastic modulus, chemical resistance, etc., as industrial material use and functional clothing use as aramid fiber and aramid thin film etc. Widely used.

  Aramid polymers are resins that are difficult to melt mold. For this reason, in order to obtain an aramid molded body, the aramid polymer is usually dissolved in a solvent, shaped in the form of a solution, and further processed to remove the solvent to obtain a molded body.

  As such a molding method, for example, a method for producing an aramid molded product in which an aramid polymer is dissolved in a sulfuric acid solution has been proposed (Patent Document 1). In this proposal, after forming a sulfuric acid solution by spinning or film formation, the molded product is washed with water, then the residual sulfuric acid is neutralized, then washed again with water if necessary, and dried, stretched, and heat treated as necessary. Etc. to obtain a molded product. However, since the method of Patent Document 1 uses a strong acid as a solvent, it is necessary to use a special material for manufacturing equipment. In addition, there are problems in the quality of molded products due to residual sulfuric acid, and problems that additives that are weak against strong acids cannot be used. For this reason, the method of patent document 1 is not economical, and the use of a molded article is also limited.

  On the other hand, as a method not using sulfuric acid as a solvent, for example, a method for producing an aramid molded product in which an aramid polymer is dissolved in an amide solvent containing an inorganic salt has been proposed (Patent Documents 2 and 3). In this proposal, examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylimidazolidinone. Examples of the kneading apparatus include screw-type extruders such as single-screw extruders and twin-screw extruders, Banbury mixers, planetary mixers, rollers, and kneaders that can be shear-kneaded. However, the methods of Patent Document 2 and Patent Document 3 cannot dissolve rapidly because the strength of shear kneading is weak. Further, there is a problem that an undissolved aramid polymer remains even after shear kneading for a long time. Also, when additives such as fillers are added, problems such as poor dispersion occur.

Further, once aramid polymer is precipitated and solidified, it is difficult to redissolve it, and as described above, an inorganic salt such as calcium chloride is required as a dissolution aid. Or a special solvent such as sulfuric acid is required. The meta-type aramid polymer has better solubility than the para-type, but the process of dissolving the meta-type aramid polymer is complicated, and it is very difficult to dissolve it appropriately without causing pollination. This is one of the issues in the application development of aramid polymer.
Thus, at present, there is no method capable of rapidly dissolving an aramid polymer in a solvent, and a solution for this is eagerly desired.

JP 2004-114474 A JP 2006-241271 A JP 2006-241624 A

  The present invention has been made against the background of the above prior art, and its main object is to provide a method and a system for producing an aramid polymer solution capable of rapidly dissolving an aramid polymer in a solvent. Furthermore, one of the objects of the present invention is to provide a method and a system for producing an aramid polymer solution with little polymer remaining undissolved. Another object of the present invention is to provide an aramid polymer molded product produced using such an aramid polymer solution.

  As a result of repeated studies to solve the above problems, the present inventor has found that the above problems can be solved by using a specific apparatus for dissolving the aramid polymer, and has reached the present invention. That is, the gist of the present invention is as follows.

(1) A method for producing an aramid polymer solution, wherein an aramid polymer is dissolved in a solvent using a thin film swirl mixer.
(2) The aramid polymer is previously mixed and dispersed in the solvent, the dispersion is supplied to the thin film swirling mixer, and the aramid polymer is dissolved in the solvent by the thin film swirling mixer. The method for producing an aramid polymer solution according to (1).
(3) A bead media is previously contained in the dispersion, and the dispersion is supplied to a thin film swirling mixer, and the aramid polymer is dissolved in the solvent by the thin film swirling mixer. (2) The method for producing an aramid polymer solution according to (2), wherein the bead media is separated from the bead medium.
(4) The thin film swirl mixer has at least two liquid supply ports, supplies the dispersion to one liquid supply port, and supplies a component corresponding to a poor solvent to the aramid polymer to the other liquid supply port. (2) The manufacturing method of the aramid polymer solution as described in (3) characterized by performing.
(5) The method for producing an aramid polymer solution according to any one of (1) to (4), wherein the solvent is a polar amide solvent.
(6) The method for producing an aramid polymer solution according to (5), wherein the solvent contains a component corresponding to a poor solvent for the aramid polymer in addition to the polar amide solvent.
(7) The aramid polymer solution according to any one of (1) to (6), wherein the thin film swirl mixer has a peripheral speed of 20 to 50 m / second and a residence time of 5 to 100 seconds. Production method.
(8) The method for producing an aramid polymer solution according to any one of (1) to (7), wherein the operating temperature of the thin-film swirl mixer is 20 to 100 ° C.
(9) The method for producing an aramid polymer solution according to any one of (2) to (8), wherein the temperature of the dispersion is −15 to 25 ° C.
(10) The method for producing an aramid polymer solution according to any one of (1) to (9), wherein the aramid polymer is in a powder form.
(11) The method for producing an aramid polymer solution according to (10), wherein the average particle diameter of the aramid polymer is in the range of 0.1 to 200 μm.
(12) A system for producing an aramid polymer solution, comprising: a means for supplying the aramid polymer; a means for supplying a solvent for the aramid polymer; and the aramid polymer and solvent respectively supplied from the supply means And a thin-film swirl mixer for swirling the aramid polymer in the solvent, and a system for producing an aramid polymer solution.
(13) A system for producing an aramid polymer solution, comprising: a means for supplying the aramid polymer; a means for supplying a solvent for the aramid polymer; and an aramid polymer and a solvent respectively supplied from each of the supplying means. A system for producing an aramid polymer solution, comprising: a dispersion means for dispersing the dispersion; and a thin-film swirling mixer for turning the dispersion from the dispersion means into a thin film and dissolving the aramid polymer in the solvent. .
(14) An aramid polymer molded product produced using the aramid polymer solution according to any one of (1) to (11) above.

  According to the present invention, an aramid polymer can be rapidly dissolved in a solvent.

Hereinafter, embodiments of the present invention will be described in detail.
[Aramid polymer]
The aramid referred to in the present invention is a polymer in which one or two or more divalent aromatic groups are directly linked by an amide bond, and the aromatic group has two aromatic rings of oxygen, sulfur or It may be bonded with an alkylene group. In addition, these divalent aromatic groups may include a lower alkyl group such as a methyl group or an ethyl group, a halogen group such as a methoxy group, or a chloro group. Furthermore, these amide bonds are not limited and may be either para-type or meta-type.

  Specific examples of such aramids include polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, copolyparaphenylene 3,4'-oxydiphenylene terephthalamide, and copolyparaphenylene. In particular, copolyparaphenylene 3,4'-oxydiphenylene terephthalamide is preferably used.

  The form of the aramid polymer applicable to the present invention is not particularly limited, and any form such as a powder form, a fiber form, and a fibril form is applicable. However, from the viewpoint that the contact area is large and dissolution is easy, powder is particularly preferable.

  The aramid polymer used in the present invention may be an aramid fiber produced by a known production method, or may be granular or powdery. Of these, powders are particularly preferred because of their good solubility in solvents of aramid polymers.

  The average particle diameter of the powdery aramid polymer is preferably in the range of 0.1 to 200 μm. If the average particle size is smaller than 0.1 μm, not only is the handling property lowered, but it is practically difficult to obtain such a powder. On the other hand, if it is larger than 200 μm, the contact area is not sufficient and the solubility is lowered, which is not preferable. The average particle diameter can be measured by a method such as observation with a microscope or a Coulter method.

[solvent]
In the present invention, the solvent can be suitably used as long as it dissolves the aramid polymer. Of these, amide solvents, particularly polar amide solvents are preferred. Examples of such polar amide solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylimidazolidinone and the like. N-methyl-2-pyrrolidone is particularly preferred from the standpoints of handleability and stability and solvent toxicity.

[Dissolution equipment]
In the present invention, it is a great feature to use a thin film swirl mixer as a dissolving device. The thin film swirl mixer in the present invention refers to a mixer having a function of swirling a solid aramid polymer dispersed in a solvent in a mixer in a thin film state and exposing it to a strong shear field.

  Here, the thin film swirl mixer is usually applied as an apparatus for dispersing a non-soluble powder in a solvent. For example, Japanese Patent Application Laid-Open No. 2006-241271 shows an example in which alumina fine particles are dispersed in an N-methyl-2-pyrrolidone solution of a polyacrylonitrile-modified rubber binder using a thin-film swirling mixer. Thus, although the thin-film swirl mixer has been conventionally known as a powder dispersion device, it can be said that there was no viewpoint of using the polymer to dissolve the polymer in a solvent. Furthermore, it has been generally considered that it is impossible to re-dissolve a hardly soluble solid aramid polymer with a disperser without using sulfuric acid or a dissolution aid.

  However, the present inventor found that when a solid aramid polymer and a solvent were swirled using a thin film swirling mixer, the solid aramid polymer could be re-dissolved without using sulfuric acid or the like. It was. The reason why the solid aramid polymer was redissolved in this way is considered to be as follows. In other words, the main factor that makes it difficult to dissolve the aramid polymer is that the aramid polymers are aggregated by a strong intermolecular force. The agglomeration due to this intermolecular force was sometimes loosened by the field, and the aramid polymer became highly dispersed. Therefore, no agglomeration occurs, and the aramid polymer can secure a sufficient contact area with the solvent. As a result, it is considered that the aramid polymer was easily dissolved in the solvent.

  An example of such a thin film swirl mixer is shown in FIG. That is, in FIG. 1, the thin film swirl mixer 1 includes a motor 10, a drive shaft 11, a stirring tool 12, a substantially cylindrical stirring tank 13, a ring-shaped weir plate 14, and a cooling means 15. The stirrer 12 is disposed inside the agitation tank 13 and has a cylindrical portion 121 that is slightly smaller in diameter than the inner diameter of the agitation tank 13 and in which a large number of holes are formed on the peripheral surface. The cylindrical portion 121 is provided coaxially with the drive shaft 11 and the stirring tank 13, and can be rotated at high speed in the stirring tank 13 by receiving a driving force from the motor 10. Liquid supply ports 131 and 132 are provided at the bottom of the stirring tank 13, and the raw material liquid is supplied into the stirring tank 13 from these liquid supply ports 131 and 132. A processing liquid discharge port 133 is provided in the upper part of the stirring tank 13, and the polymer solution that has flowed to the upper part beyond the barrier plate 14 is discharged to the outside through the processing liquid discharge port 133. ing. The cooling means 15 includes a cooling container 150 that surrounds the outside of the agitation tank 13, and a cooling water supply port 151 and a discharge port 152 that are connected to the inside of the cooling container 150. Cooling water is cooled from the supply port 151. It is comprised so that it may flow to the discharge port 152 through the inside of the container 150, and it becomes possible to control the stirring tank 13 to predetermined temperature by this. In such a thin film swirl mixer 1, when a small amount of liquid to be processed is supplied to the stirring tank 13 and the stirring tool 12 is rotated at a high speed, the liquid 16 to be processed rises in a thin cylindrical shape along the inner surface of the stirring tank 13. The mixture is stirred and exposed to a strong shear field. Such a thin film swirl mixer is described in detail in, for example, Japanese Patent Application Laid-Open No. 2001-300281. Further, as the thin film swirl mixer in the present invention, for example, a thin film swirl mixer manufactured by Primix Co., Ltd. K. Examples include Fillmix (registered trademark, model FM-80-50). In the present invention, the thin film swirling mixer is not limited to the configuration shown in FIG. 1, and the liquid to be treated is swirled into a thin film, for example, a type having a rotating blade as disclosed in JP-A-11-333275. Any can be used as long as it forms a strong shear field.

[Supply of aramid polymer and solvent]
The supply of the aramid polymer and the solvent to the thin film swirling mixer may be a method in which the aramid polymer powder is previously dispersed in the solvent and this dispersion is fed to the thin film swirling mixer. The aramid polymer powder and the solvent may be separately supplied. A method of supplying to a thin film swirl mixer and mixing and dissolving in the thin film swirl mixer may be used.

  There are no particular limitations on the method of transferring the liquid (solvent or the like) or powder (aramid polymer powder or the like). The liquid may be transferred by a pump or the like capable of transferring liquid, and the powder may be transferred by a method of quantitatively transferring the powder such as a feeder.

[Dispersion of aramid polymer in solvent]
When an aramid polymer is dissolved in a solvent using a thin film swirl mixer, a method in which an aramid polymer is mixed with a solvent in advance, a dispersed dispersion is prepared, and the dispersion is fed to a thin film swirl mixer is preferable. The method for obtaining this dispersion is not particularly limited.For example, the solvent and the solid aramid polymer are placed in a tank in which stirring blades such as a turbine blade, a propeller blade, a paddle blade, and an anchor blade are installed. It can be easily obtained by stirring with a stirring blade.

  The method for supplying this dispersion to the thin film swirl mixer is not particularly limited. What is necessary is just to supply with the quantitative property of the grade which does not produce the malfunction in a driving | operation. Specific supply means include a gear pump, a tube pump, a flanger pump, a diaphragm pump, a rotary pump, and the like, and any of these methods can be suitably used.

[Bead media]
The present invention is a method for producing an aramid polymer solution by including bead media in a dispersion, supplying the dispersion to a thin-film swirling mixer, and then separating the bead media to dissolve the aramid polymer in a solvent. May be. Mixing bead media in the dispersion is a more preferable form from the viewpoint of promoting dissolution of the aramid polymer.

  When the bead media is mixed with the dispersion and this dispersion is fed to the thin film swirl mixer, the aramid polymer is pulverized and refined by the bead media in the thin film swirl mixer, so that the dissolution proceeds efficiently and quickly.

  As the bead media used in the present invention, glass beads, alumina beads, zirconia beads, zircon beads and the like are preferably used. The bead diameter is not particularly limited, but is preferably 0.1 μm or more and 1 mm or less. When the bead diameter is larger than 1 mm, a sufficient pulverizing effect may not be obtained. When the bead diameter is smaller than 0.1 μm, the handling property is lowered by a separation operation or the like, which is not preferable. The bead content is not particularly limited, but it is generally preferable to add 1 to 5 times the weight of the aramid polymer. If it is less than 1 time, sufficient pulverization effect may not be obtained and dissolution may not be promoted. If it exceeds 5 times, the separation operation becomes difficult and the yield of the polymer solution may be reduced.

  The mixing of the bead media can be easily performed by adding the bead media together when preparing a dispersion composed of an aramid polymer and a solvent. In this way, the dispersion liquid in which the bead media is mixed can also be fed to the thin film swirl mixer by the same method as the above-described liquid feeding method.

  When the bead media is mixed with the dispersion, the aramid polymer solution containing the bead media is discharged from the thin film swirl mixer. In order to obtain an aramid polymer solution, it is necessary to remove the bead media. The removal of the bead media can be easily performed by techniques such as filtration separation and sedimentation separation.

[Poor solvent]
In the present invention, in addition to the polar amide solvent, the aramid polymer may contain a component corresponding to a poor solvent. In the present invention, the aramid polymer can be dissolved even if a component that becomes a poor solvent for the aramid polymer is added in addition to the polar amide solvent.

  Examples of the poor solvent include alcohol solvents such as methanol and ethanol, polyhydric alcohol solvents such as ethylene glycol, propylene glycol, diethylene glycol and tripropylene glycol, and water. These components are added as long as they do not inhibit dissolution of the aramid polymer. The specific addition amount depends on the combination of the aramid polymer, the polar amide solvent, and the poor solvent, but it is possible to add the poor solvent in a range of approximately 50% by weight or less with respect to the total amount of the solvent.

  When producing an aramid porous membrane using a phase separation method, a technique for controlling the porous structure by adding these poor solvents to an aramid polymer solution is known, and a suitable porous structure can be obtained by adding an appropriate amount of this poor solvent. It is often done. However, since it is difficult to dissolve an aramid polymer in a solvent in which a predetermined amount of a poor solvent has been added in advance, a step of adding a poor solvent after preparing an aramid polymer solution in which an aramid polymer is dissolved in a polar amide solvent is required It was very cumbersome. However, since the thin film swirl mixer is applied in the present invention, dissolution can be performed efficiently. Therefore, it can be sufficiently dissolved in a solvent to which a poor solvent has been added in advance, and is a very effective means for obtaining an aramid polymer solution used for producing a porous film.

  When the poor solvent is added, the poor solvent and the polar amide solvent may be mixed in advance and fed to the thin film swirl mixer. However, the poor solvent is supplied from another supply port, and the poor solvent is fed into the thin film swirl mixer. And a polar amide solvent are more preferable. By adopting such a method, it is possible to shorten the dissolution time and improve productivity. This technique is particularly effective when a large amount of poor solvent is added.

[Method for producing aramid polymer solution]
In the present invention, the above-described thin film swirl mixer is used for the production of the aramid polymer solution. The aramid polymer is exposed to a strong shear field in the thin film swirl mixer, and the solid aramid polymer is first very well dispersed in the solvent. For this reason, the contact area between the solid aramid polymer and the solvent becomes large and can be easily dissolved.

  In the present invention, the peripheral speed during operation of the thin film swirl mixer is preferably 20 to 50 m / sec. If the peripheral speed is slower than 20 m / sec, it is difficult to sufficiently dissolve the aramid polymer, which is not preferable. On the other hand, if the peripheral speed exceeds 50 m / sec, the shear heat generation becomes too large and the temperature control becomes difficult.

  In the present invention, the residence time during the operation of the thin film swirling mixer is preferably 5 to 100 seconds, and more preferably 10 to 60 seconds. If the residence time is shorter than 5 seconds, the aramid polymer may not be sufficiently dissolved. Further, if it exceeds 100 seconds, heat due to shear heat generation is accumulated, and it is not only difficult to sufficiently remove it, but also productivity is lowered, which is not preferable.

  In this invention, 20-100 degreeC is suitable for the operating temperature of a thin film swirl mixer. If the operating temperature is lower than 20 ° C., the aramid polymer cannot be sufficiently dissolved. On the other hand, if the operating temperature exceeds 100 ° C., evaporation of the solvent and the like are problematic and not preferable. Moreover, in the system to which a poor solvent is added, a problem of gelation also occurs. When the poor solvent is added, there arises a problem that the aramid polymer solution is gelated when exposed to a high temperature, and a suitable temperature range is determined in detail by the amount of the poor solvent added, but is generally 100 ° C. or less, more preferably Is 70 ° C. or lower, more preferably 60 ° C. or lower.

  Although the temperature of this dispersion liquid sent to a thin film swirl mixer is not specifically limited, -15-25 degreeC is suitable. When the temperature is lower than −15 ° C., the solvent is solidified, which may hinder liquid feeding. The upper limit temperature is not particularly limited, but at least heating is unnecessary. From such a viewpoint, the temperature need not be higher than 25 ° C. Further, the liquid temperature rises due to the shear heat generated during the operation of the thin film swirling mixer, and it is necessary to remove this efficiently. Considering this efficiency, a low temperature of 25 ° C. or lower is preferable for operation, and a low temperature of 0 ° C. or lower. Is more preferable. Furthermore, for efficient dissolution, it is not preferable to swell the aramid polymer with a polar amide solvent in this dispersion, and from this point of view, 25 ° C. or lower is preferable, and 0 ° C. or lower is more preferable. Preferred is -10 ° C or lower.

[Aramid polymer solution production system]
In the present invention, the above-described method for producing an aramid polymer solution can be suitably realized by the following production system, for example.
For example, as shown in FIG. 2, an aramid polymer solution production system S of the present invention includes a polymer supply means 2 for supplying an aramid polymer, a good solvent supply means 3 for supplying a good solvent for dissolving an aramid polymer, The aramid polymer and the solvent respectively supplied from the supply means 2 and 3 are swirled into a thin film, and a thin film swirling mixer 1 for dissolving the aramid polymer in the solvent and a polymer solution recovery container 4 are provided. The polymer supply means 2 is configured with a feeder or the like, and the good solvent supply means 3 is configured with a pump or the like. Further, as the thin film swirl mixer 1, the type shown in FIG. 1 can be used.

  Further, the system S for producing an aramid polymer solution of the present invention may be further added with a disperser for preparing a dispersion by mixing and dispersing an aramid polymer and a solvent in the system shown in FIG. That is, for example, as shown in FIG. 3, the disperser 5 is supplied with the aramid polymer from the polymer supplying means 2 and supplied with the good solvent from the good solvent supplying means 3. The dispersed liquid is configured to be supplied to the thin film swirl mixer 1. As such a disperser 5, one having a stirring blade such as a turbine blade as described above can be used.

  Further, the system S for producing an aramid polymer solution of the present invention may further include a configuration for supplying bead media to the dispersion in the system shown in FIG. That is, for example, as shown in FIG. 4, the system S includes a bead media supply means 6 for supplying the bead media to the disperser 5, whereby the bead media is contained in the dispersion liquid produced by the disperser 5. Appropriate amount is included. Further, the system S includes a bead media separation means 7 between the thin film swirl mixer 1 and the collection container 4, thereby separating only the bead media from the polymer solution produced by the thin film swirl mixer 1, The polymer solution from which the bead media is removed can be transferred to the collection container 4. As shown in FIG. 4, the bead media separated by the bead media separation means 7 may be returned to the bead media supply means 6 again, so that the bead media is wasted. Resources can be used effectively.

  When a component that becomes a poor solvent for the aramid polymer is added to the aramid polymer solution, a means for supplying a poor solvent may be added to the system shown in FIG. That is, as shown in FIG. 5, the system S includes a poor solvent supply means 8 for supplying a poor solvent to the thin film swirl mixer 1. Such a poor solvent supply means 8 includes a pump and the like.

  Another example of the system provided with the poor solvent supply means is as shown in FIG. That is, in FIG. 6, the system S includes a polymer supply means 2, a good solvent supply means 3, a disperser 5, a poor solvent supply means 8, a thin film swirling mixer 1, and a recovery container 4. ing. In this case, the thin film swirl mixer 1 needs to be provided with at least two liquid supply ports. A dispersion liquid containing an aramid polymer and a good solvent is supplied from one disperser 5 to one liquid supply port, and a poor solvent for an aramid polymer is supplied from the poor solvent supply means 8 to the other liquid supply port. It has become.

  As another example of the system provided with the poor solvent supply means, for example, the system shown in FIG. That is, in FIG. 7, the system S includes a polymer supply unit 2, a good solvent supply unit 3, a thin film swirl mixer 1, a poor solvent supply unit 8, a mixer 9, and a recovery container 4. ing. The thin film swirl mixer 1 is supplied with an aramid polymer from the polymer supply means 2 and a good solvent from the good solvent supply means 3. The aramid polymer solution prepared by the thin film swirl mixer 1 and the poor solvent from the poor solvent supply means 8 are supplied to the mixer 9, and these are mixed by the mixer 9 to produce a final polymer solution. It has come to be. In addition, as the mixer 9, the thing similar to the disperser 5 mentioned above can be used.

[Aramid polymer moldings]
The present invention also includes an aramid polymer molded product produced using the aramid polymer solution produced by the method described above.
The aramid polymer solution prepared by the above-described method does not contain sulfuric acid, inorganic salt, or the like as in the prior art disclosed in Patent Document 1, and the prior art disclosed in Patent Documents 2 and 3 Thus, the possibility that the undissolved aramid polymer remains is extremely low. Therefore, a molded product obtained by using such an aramid polymer solution has a high quality without containing impurities such as sulfuric acid and inorganic salts. Examples of such molded articles include aramid fibers and aramid thin films, and can be widely used for various applications such as electronic materials, industrial materials, and functional clothing.

Hereinafter, the present invention will be described more specifically with reference to examples.
[Measurement of average particle size]
The average particle size of the aramid polymer is obtained by observing 30 samples of the aramid polymer with a scanning electron microscope, obtaining the area of the particle from the image, obtaining the diameter calculated when this is approximated by a circle, and calculating the average particle size as the average particle size. did.

[Example 1]
15 parts by weight of CONEX powder (registered trademark; manufactured by Teijin Techno Products Co., Ltd .: average particle size: 100 μm), which is a meta-type wholly aromatic polyamide, is added to 85 parts by weight of dimethylacetamide cooled to −10 ° C., and a radial flow turbine blade The mixture was stirred for 5 minutes to obtain a dispersion.
This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 20 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 27 m / sec, and the temperature was adjusted with a chiller so that the internal temperature was 60 ° C. As a result of degassing the liquid coming out of the thin-film swirling mixer, a clear and viscous Conex dimethylacetamide solution was obtained. In this solution, no undissolved component in the form of a spatter was observed.
The obtained solution was cast on a glass plate with a doctor blade with a clearance of 500 μm and dried at 150 ° C. As a result, a transparent film was obtained.

[Example 2]
58 parts by weight of CONEX powder (registered trademark; manufactured by Teijin Techno Products: average particle size: 100 μm), meta type wholly aromatic polyamide, 660 parts by weight of dimethylacetamide, and 282 parts by weight of tripropylene glycol are mixed at room temperature. The mixture was stirred with a flow turbine blade for 5 minutes to obtain a dispersion.
This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 60 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 35 m / sec, and the temperature was adjusted with a chiller so that the internal temperature was 50 ° C. As a result of defoaming the liquid coming out of the thin film swirl mixer, a transparent and viscous Conex solution was obtained. In this solution, no undissolved component in the form of a spatter was observed. This shows that Conex can be dissolved in dimethylacetamide containing tripropylene glycol, which is a poor solvent.
The obtained solution was cast on a glass plate with a doctor blade with a clearance of 200 μm, and immersed in a coagulation liquid consisting of water: dimethylacetamide: tripropylene glycol = 50: 35: 15 (weight ratio). A porous membrane was obtained.

[Example 3]
Cornex powder (registered trademark; manufactured by Teijin Techno Products: average particle size: 100 μm) 58 parts by weight, 660 parts by weight of dimethylacetamide, 282 parts by weight of tripropylene glycol, and alumina having a particle size of 0.1 mm 100 parts by weight of beads were mixed at room temperature and stirred for 5 minutes with a radial flow turbine blade to obtain a dispersion.
This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 10 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 30 m / sec, and the temperature was adjusted with a chiller so that the internal temperature was 50 ° C. The liquid coming out of the thin film swirling mixer was filtered to separate the alumina beads and defoamed. As a result, a transparent and viscous Conex solution was obtained. In this solution, no undissolved component in the form of a spatter was observed. This shows that Conex can be dissolved in dimethylacetamide containing tripropylene glycol, which is a poor solvent.
The obtained solution was cast on a glass plate with a doctor blade with a clearance of 200 μm, and immersed in a coagulation liquid consisting of water: dimethylacetamide: tripropylene glycol = 50: 35: 15 (weight ratio). A porous membrane was obtained.

[Example 4]
A separable flask having a stirring blade, a thermometer, a nitrogen inlet pipe and a powder addition port was sufficiently dried, charged with 2200 parts by weight of N-methyl-2-pyrrolidone (NMP), and vacuum-dried at 200 ° C. for 2 hours. 151.07 parts by weight of calcium powder was added, and the mixture was heated to 100 ° C. and completely dissolved. The temperature was returned to room temperature, and 68.23 parts by weight of paraphenylenediamine was added and completely dissolved. While maintaining this solution at 20 ° C., 124.97 parts by weight of terephthalic acid dichloride was added little by little. Thereafter, the solution was allowed to stand for 1 hour while being kept at 20 ° C. with stirring. Then, the NMP solution of polyparaphenylene terephthalamide was obtained by neutralizing with calcium hydroxide.
200 parts by weight of ion-exchanged water was placed in a mixer and stirred, and 100 parts by weight of the NMP solution of polyparaphenylene terephthalamide was added in small portions. As a result, a dispersion liquid in which polyparaphenylene terephthalamide was precipitated was obtained in the mixer. The dispersion was subjected to suction filtration to obtain polyparaphenylene terephthalamide powder having an average particle diameter of 5 μm.

  5 parts by weight of the polyparaphenylene terephthalamide powder and 95 parts by weight of NMP were mixed at room temperature and stirred for 5 minutes with a radial flow turbine blade to obtain a dispersion. This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 90 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 40 m / sec, and the temperature was adjusted with a chiller so that the internal temperature became 70 ° C. As a result of degassing the liquid coming out of the thin film swirl mixer, a viscous polyparaphenylene terephthalamide solution was obtained. This solution was cast on a glass plate with a doctor blade with a clearance of 500 μm and dried at 150 ° C. As a result, a transparent film was obtained. From this, it was confirmed that the paraphenylene terephthalamide powder was dissolved in NMP.

[Example 5]
5 parts by weight of paraphenylene terephthalamide powder of Example 4, 95 parts by weight of NMP, and 10 parts by weight of alumina beads having a particle diameter of 0.1 mm were mixed at room temperature and stirred for 5 minutes with a radial flow turbine blade to obtain a dispersion. It was.
This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 30 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 40 m / sec, and the temperature was adjusted with a chiller so that the internal temperature became 70 ° C. The liquid coming out of the thin-film swirling mixer was filtered to separate the alumina beads and defoamed. As a result, a viscous polyparaphenylene terephthalamide solution was obtained. This solution was cast on a glass plate with a doctor blade with a clearance of 500 μm and dried at 150 ° C. As a result, a transparent film was obtained. From this, it was confirmed that the paraphenylene terephthalamide powder was dissolved in NMP.

[Example 6]
In a stirring tank in which nitrogen was flowing inside, NMP was weighed so that paraphenylenediamine and 3,4'-diaminodiphenyl ether were equimolar and dissolved. To this diamine solution, terephthalic acid dichloride was weighed and added in an amount approximately equal to the total molar amount of diamine. After completion of the reaction, the solution was neutralized with calcium hydroxide to obtain an NMP solution of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide.
200 parts by weight of ion-exchanged water was placed in a mixer and stirred, and 100 parts by weight of the NMP solution of copolyparaphenylene 3,4'-oxydiphenylene terephthalamide was added in small portions. As a result, a dispersion liquid in which copolyparaphenylene • 3,4′-oxydiphenylene terephthalamide was precipitated was obtained in the mixer. The dispersion was subjected to suction filtration to obtain polyparaphenylene terephthalamide powder having an average particle size of 10 μm. The calcium chloride remaining in this process has been removed.
5 parts by weight of the copolyparaphenylene-3,4'-oxydiphenylene terephthalamide powder, 95 parts by weight of NMP, and 10 parts by weight of alumina beads having a particle diameter of 0.1 mm were mixed at -10 ° C., and the radial flow turbine blade was used. Stir for 5 minutes to obtain a dispersion.

  This dispersion was transferred to a thin film swirling mixer T.P. K. The solution was fed to Filmix (registered trademark; manufactured by Primix: Model FM-80-50) so that the residence time was 30 seconds. At this time, the thin-film swirling mixer was operated at a peripheral speed of 40 m / sec, and the temperature was adjusted with a chiller so that the internal temperature became 70 ° C. As a result of filtering the liquid coming out of the thin film swirling mixer, separating the alumina beads and defoaming, a viscous copolyparaphenylene 3,4'-oxydiphenylene terephthalamide solution was obtained. This solution was cast on a glass plate with a doctor blade with a clearance of 500 μm and dried at 150 ° C. As a result, a transparent film was obtained. From this, it was confirmed that the copolyparaphenylene 3,4'-oxydiphenylene terephthalamide powder was dissolved in NMP.

[Example 7]
5 parts by weight of Conex powder (registered trademark; manufactured by Teijin Techno Products Co., Ltd .: average particle size: 100 μm), which is a meta-type wholly aromatic polyamide, is placed in 57 parts by weight of dimethylacetamide cooled to −10 ° C. Stir for 5 minutes to obtain a dispersion.
A thin film swirling mixer T.M. with a tube pump so that the dispersion liquid has a residence time of 30 seconds. K. The solution was fed to Fillmix (registered trademark; manufactured by Primix: Model FM-80-50). At the same time, 38 parts by weight of tripropylene glycol was mixed with 57 parts by weight of dimethylacetamide from another supply port, and the thin film swirl mixer was supplied. At this time, the thin-film swirling mixer was operated at 28 m / sec and controlled with a chiller so that the internal temperature was 40 ° C. As a result of defoaming the liquid coming out of the thin film swirl mixer, a transparent and viscous Conex solution was obtained. In this solution, no undissolved component in the form of a spatter was observed. This shows that Conex can be dissolved in dimethylacetamide containing tripropylene glycol, which is a poor solvent.

[Comparative Example 1]
15 parts by weight of Conex powder (registered trademark; manufactured by Teijin Techno Products Co., Ltd .: average particle size: 100 μm), which is a meta-type wholly aromatic polyamide, is placed in 85 parts by weight of dimethylacetamide cooled to −10 ° C. Stir for 5 minutes. Stirring was continued and the mixture was heated to 60 ° C., but a gel-like pollen component was observed and could not be dissolved well.

[Comparative Example 2]
58 parts by weight of CONEX powder (registered trademark; manufactured by Teijin Techno Products: average particle size: 100 μm), meta type wholly aromatic polyamide, 660 parts by weight of dimethylacetamide, and 282 parts by weight of tripropylene glycol are mixed at room temperature. The mixture was stirred for 5 minutes with a flow turbine blade. Stirring was continued and the mixture was heated to 50 ° C., but a large amount of undissolved components were observed.

[Comparative Example 3]
5 parts by weight of polyparaphenylene terephthalamide obtained in Example 4 was put into 95 parts by weight of NMP, and dispersed at −10 ° C. with a radial flow turbine blade for 5 minutes. Thereafter, the mixture was heated to 70 ° C. with stirring, but dissolution of polyparaphenylene terephthalamide was not confirmed.

[Comparative Example 4]
5 parts by weight of the copolyparaphenylene 3,4'-oxydiphenylene terephthalamide obtained in Example 6 was put into 95 parts by weight of NMP, and dispersed at −10 ° C. with a radial flow turbine blade for 5 minutes. Thereafter, the mixture was heated to 70 ° C. with stirring, but dissolution of polyparaphenylene terephthalamide was not confirmed.

  As is apparent from the results shown in Examples 1 to 7, in the examples of the present invention using a thin film swirl mixer as a means for dissolving the aramid polymer in the solvent, the aramid polymer is rapidly dissolved in the solvent. On the other hand, as a means for dissolving the aramid polymer in the solvent, in Comparative Examples 1 to 4 using a general-purpose stirring device (equipped with a radial flow turbine as a stirring blade), complete dissolution of the aramid polymer in the solvent was not recognized.

  According to the present invention, an aramid polymer can be rapidly dissolved in a solvent, and at the same time, additives such as bead media and filler can be uniformly dispersed.

It is sectional drawing which showed typically the thin film swirl mixer used for the manufacturing method of the aramid polymer solution of this invention. It is the schematic diagram which showed the 1st example of the manufacturing system of the aramid polymer solution of this invention. It is the schematic diagram which showed the 2nd example of the manufacturing system of the aramid polymer solution of this invention. It is the schematic diagram which showed the 3rd example of the manufacturing system of the aramid polymer solution of this invention. It is the schematic diagram which showed the 4th example of the manufacturing system of the aramid polymer solution of this invention. It is the schematic diagram which showed the 5th example of the manufacturing system of the aramid polymer solution of this invention. It is the schematic diagram which showed the 6th example of the manufacturing system of the aramid polymer solution of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS S ... Manufacturing system of aramid polymer solution 1 ... Thin film swirling mixer 2 ... Polymer supply means 3 ... Good solvent supply means 4 ... Collection container 5 ... Disperser 6 ... Bead media supply means 7 ... Bead media separation means 8 ... Poor solvent supply means 9 ... Mixer

Claims (13)

  A method for producing an aramid polymer solution, wherein an aramid polymer is dissolved in a solvent using a thin film swirl mixer. The aramid polymer is previously mixed and dispersed in the solvent,
2. The method for producing an aramid polymer solution according to claim 1, wherein the dispersion is supplied to the thin film swirl mixer, and the aramid polymer is dissolved in the solvent by the thin film swirl mixer. In advance, bead media is included in the dispersion,
Supply this dispersion to a thin film swirl mixer, dissolve the aramid polymer in the solvent by the thin film swirl mixer,
3. The method for producing an aramid polymer solution according to claim 2, wherein the bead media is then separated from the aramid polymer solution. The thin film swirl mixer comprises at least two liquid supply ports,
Supplying the dispersion to one liquid supply port;
The method for producing an aramid polymer solution according to claim 2 or 3, wherein a component corresponding to a poor solvent for the aramid polymer is supplied to the other liquid supply port.   The method for producing an aramid polymer solution according to any one of claims 1 to 4, wherein the solvent is a polar amide solvent.   6. The method for producing an aramid polymer solution according to claim 5, wherein the solvent contains a component corresponding to a poor solvent for the aramid polymer in addition to the polar amide solvent.   The method for producing an aramid polymer solution according to any one of claims 1 to 6, wherein the thin film swirl mixer has a peripheral speed of 20 to 50 m / sec and a residence time of 5 to 100 sec.   The method for producing an aramid polymer solution according to any one of claims 1 to 7, wherein an operating temperature of the thin-film swirl mixer is 20 to 100 ° C.   The method for producing an aramid polymer solution according to any one of claims 2 to 8, wherein the temperature of the dispersion is -15 to 25 ° C.   The method for producing an aramid polymer solution according to any one of claims 1 to 9, wherein the aramid polymer is in a powder form.   The method for producing an aramid polymer solution according to claim 10, wherein the average particle diameter of the aramid polymer is in the range of 0.1 to 200 µm. A system for producing an aramid polymer solution,
Means for supplying the aramid polymer;
Means for supplying a solvent for the aramid polymer;
A system for producing an aramid polymer solution, comprising: a thin film swirling mixer that swirls the aramid polymer and the solvent respectively supplied from each of the supplying means into a thin film and dissolves the aramid polymer in the solvent. A system for producing an aramid polymer solution,
Means for supplying the aramid polymer;
Means for supplying a solvent for the aramid polymer;
Dispersing means for mixing and dispersing the aramid polymer and solvent supplied from each of the supplying means,
A system for producing an aramid polymer solution, comprising: a thin film swirling mixer that swirls the dispersion from the dispersing means into a thin film and dissolves the aramid polymer in the solvent.

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