JP7130367B2 - An organic resin solution, a spinning solution, a method for producing a fiber assembly using the spinning solution, and a method for producing a film and a composite using the organic resin solution - Google Patents

Description

The present invention relates to an organic resin solution, a spinning solution comprising the organic resin solution, a method for producing a fiber aggregate using the spinning solution, and a method for producing a film and a composite using the organic resin solution.

An organic resin solution obtained by dissolving an organic resin in a solvent is a solution from which materials useful for various industrial applications can be prepared. For example, a fiber aggregate composed of organic resin fibers can be prepared by spinning using an organic resin solution as a spinning solution, and an organic resin film can be prepared by spreading the organic resin solution into a sheet and then removing the solvent. It is useful for various industrial applications using organic resin solutions, such as applying an organic resin solution to an object to be coated and then removing the solvent to prepare a composite with an organic resin film on the surface of the object to be coated. materials can be prepared.
However, when the applicant of the present application continued to study, it was found that there is the following problem. In other words, when an organic resin containing a nitrogen atom in its chemical structure is used to prepare an organic resin solution, the organic resin solution is denatured over time such that the organic resin precipitates in the solution, resulting in poor stability. had a problem. And when an organic resin solution with poor stability is used, it is difficult to prepare materials useful for various industrial applications.

In particular, it has been found that the spinning solution comprising the organic resin solution has the following problems.
Fiber aggregates (for example, nonwoven fabrics) made of fibers with a small average fiber diameter and CV value of fiber diameter have various performances such as separation performance, liquid retention performance, wiping performance, hiding performance, insulation performance, and flexibility. known to be excellent.
As a method for producing such a fiber assembly, a method using a spinning solution obtained by dissolving an organic resin constituting the fibers in a solvent, for example, by applying an electrostatic force to reduce the diameter of the spinning solution and making it into fibers, spinning An electrostatic spinning method in which the spun fibers are collected to produce a fiber aggregate, or an accompanying air current is applied to reduce the diameter of the spinning solution and make it into fibers, and the spun fibers are collected to form a fiber aggregate. Manufacturing methods (for example, Japanese Unexamined Patent Application Publication No. 2011-012372) are known.

The applicant of the present application provides a fiber aggregate composed of fibers composed of an organic resin containing nitrogen atoms in its chemical structure in a form of fibers having a small average fiber diameter and a CV value of the fiber diameter. An attempt was made to prepare a spinning solution by dissolving it in a solvent and to produce a fiber aggregate using the spinning solution.
However, the prepared spinning solution has a problem that the organic resin is denatured with the lapse of time such as deposition of the organic resin in the spinning solution, resulting in poor stability.
Even if an attempt is made to produce a fiber assembly using such a modified spinning solution, the spinning solution may not be discharged stably from the tip of the nozzle during spinning, and fiberization may not be achieved, failing to produce a fiber assembly. rice field. Alternatively, even if the fiber assembly can be manufactured, there are many non-fiber materials such as shot in the manufactured fiber assembly, and / or the average fiber diameter and the CV value of the fiber diameter in the manufactured fiber assembly are not intended. However, it was not possible to provide a desired form of a fiber assembly.

In addition, when an organic resin film or a composite having an organic resin coating on the surface of an object to be coated is produced using an organic resin solution having poor stability, the produced film or composite may have precipitates in the organic solution. Due to the presence of the organic resin, uneven portions such as uneven portions and portions with locally different physical properties such as rigidity are present, and films and composites of desired aspects cannot be provided. Met.

The present invention produces a highly stable organic resin solution containing an organic resin containing a nitrogen atom in its chemical structure, a spinning solution comprising the organic resin solution, and a fiber assembly, film, or composite in a desired mode. The purpose is to provide a method.

The present invention
"[1] A spinning solution consisting of an organic resin solution containing urea and polybenzimidazole as an organic resin, which is thinned and fibrillated by the action of electrostatic force, and collected on a collector. A spinning solution used to form a fibrous web on said collector.
[2] A step of reducing the diameter of the spinning solution according to claim 1 by the action of an electrostatic force, converting it into fibers, and collecting it on a collector to form a fiber web on the collector; A method for producing a fiber assembly. "
is.

As a result of continued studies, the applicant of the present application found that the stability of the organic resin solution can be improved by adding a urea-based compound to the organic resin solution containing the organic resin containing nitrogen atoms in its chemical structure.
Therefore, the organic resin solution according to the present invention and the spinning solution comprising the organic resin solution are excellent in stability.
In a method for producing a fiber assembly comprising a step of forming a fiber web on a collecting body by reducing the diameter of the spinning solution by the action of electrostatic force , converting the spinning solution into fibers, and collecting the spinning solution on the collecting body, By using the spinning solution with excellent stability according to the invention, spinning can be performed in a state where the spinning solution is stably discharged from the tip of the nozzle, thereby preventing the presence of many non-fiber materials such as shot. and/or preventing an unintended increase in the average fiber diameter or the CV value of the fiber diameter, thereby producing a desired mode of fiber assembly.
In addition, by using the organic resin solution according to the present invention, it is possible to prevent the presence of uneven portions such as uneven portions and portions with locally different physical properties such as rigidity, thereby achieving a desired form of film or film. Composites can be made.

The present invention relates to an organic resin solution containing a urea-based compound and an organic resin containing a nitrogen atom in its chemical structure, and a spinning solution comprising the organic resin solution (hereinafter sometimes referred to as an organic resin solution or spinning solution). , and various configurations such as the following configurations can be selected as appropriate.

The urea-based compound as used in the present invention is a compound having a urea skeleton (N—C(O)—N or N—C(S)—N) in its chemical structure, such as urea, thiourea, hydroxyurea , dimethylol urea, diacetyl urea, ethylene urea, phenyl urea, triphenyl urea, tetraphenyl urea, N-benzoyl urea, N,N'-dibenzoyl urea, guanyl urea phosphate, N,N'-dimethylacetyl urea, benzenesulfonyl Urea, p-toluenesulfonylurea, alkyl urea having an alkyl group having 1 to 6 carbon atoms (e.g., methyl urea, dimethyl urea, trimethyl urea, tetramethyl urea, tetraethyl urea, ethyl urea, diethyl urea, etc.), formyl urea, etc. can be used singly or in mixtures. Salts of these urea (for example, nitrates, hydrochlorides, etc.) may also be used.

In particular, as will be described later, in the step of removing the solvent from the organic resin solution or the spinning solution with a reduced diameter (for example, the step of heating or the step of removing the solvent by immersion in water), it can be removed together with the solvent. Urea-based compounds are preferably used. By using such an organic resin solution or spinning solution containing a urea-based compound, a material in which no urea-based compound is finally present (a fiber aggregate composed of constituent fibers in which no urea-based compound is present, or , films and composites in which urea-based compounds are not present), or materials with a small amount of urea-based compounds (fiber assembly consisting of constituent fibers with a small amount of urea-based compounds, or low abundance films, composites, etc.). Urea, dimethylurea, phenylurea, etc. can be used as such a removable urea-based compound.

In addition, it is preferable to use a urea-based compound having a low molecular weight (low molecular weight compound or monomer) such as urea, dimethylurea, and phenylurea. By using an organic resin solution or spinning solution containing such a urea-based compound, the mass of the urea-based compound contained in the organic resin solution or spinning solution can be further reduced, and finally the urea-based compound is not present. Materials (fiber aggregates composed of constituent fibers without urea-based compounds, or films and composites without urea-based compounds), or materials with a small amount of urea-based compounds (urea-based compounds It is possible to provide a fiber aggregate composed of constituent fibers with a small amount of , or a film or composite with a small amount of urea-based compounds.

The organic resin having a nitrogen atom in its chemical structure as used in the present invention refers to a compound having a nitrogen atom in its chemical structure, and a resin having a heterocyclic structure is particularly preferable because of its excellent heat resistance. For example, polyazole resin (e.g., polybenzimidazole, polybenzoxazole, polybenzothiazole, polypyrrole, polycarbazole, etc.), polyimide resin (e.g., aliphatic polyimide, aromatic polyimide, polymaleimide, etc.), polyamic acid, polypyridine , polyquinoxaline, etc. can be used singly or as a mixture of multiple types.

The type of organic resin containing nitrogen atoms in its chemical structure is appropriately selected depending on the physical properties required for the material to be provided (for example, fiber assembly, film, composite, etc., hereinafter collectively referred to as material). However, it is preferable to use polybenzimidazole because it is possible to provide a material with excellent heat resistance.
Although polybenzimidazole is not particularly limited, it can be, for example, an organic resin having a repeating unit represented by the following formula (I) or (II).

In formula (II), Y is a substituent element selected from O and S, or a carbon-carbon bond (eg, a divalent group such as —O—, —CO—, —SO ₂ —). Moreover, the Y portion may be a σ bond that bonds the repeating units represented by the formula (I) described above.
Z is also divalent C1-C10 alkanediyl, divalent C2-C10 alkenediyl, divalent C6-C15 aryl, divalent C5-C15 heteroaryl, divalent C5-C15 heterocyclyl, divalent C6-C19 arylsulfone, and Divalent radicals having at least one aromatic ring selected from the group consisting of divalent C6-C19 aryl ethers are preferred. For example, functional groups having groups as described in the following formulas are preferred.

The type of solvent constituting the organic resin solution or spinning solution according to the present invention can be appropriately selected as long as it is a solvent capable of dissolving at least the urea-based compound and the organic resin containing nitrogen atoms in its chemical structure. , for example, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl methyl ketone, ethanol, sulfuric acid, polyphosphoric acid, alkaline solutions, etc. can be used singly or as a mixture of multiple solvents.

The mass of the urea-based compound contained in the organic resin solution or spinning solution should be appropriately selected so as to match the mass of the organic resin containing nitrogen atoms in the chemical structure contained in the organic resin solution or spinning solution so as to provide the desired material. be. However, if the mass of the urea-based compound contained in the organic resin solution or spinning solution is too small, the effect of improving the stability of the organic resin solution or spinning solution may not be sufficiently exhibited. If the mass of the urea-based compound contained in the liquid is too large, it may become difficult to produce the material.

Therefore, the mass of the urea-based compound contained in the organic resin solution or spinning solution is 0.01 to 0.01 when the mass of the organic resin containing nitrogen atoms in the chemical structure contained in the organic resin solution or spinning solution is 100 parts. It is preferably 100 parts by mass, more preferably 0.1 to 50 parts by mass, and most preferably 1 to 20 parts by mass.

The mass of the organic resin containing a nitrogen atom in its chemical structure contained in the organic resin solution or the spinning solution is appropriately selected according to the usage conditions of the organic resin solution so as to provide the desired material. Specifically, when the mass of the solvent is 100 parts, it is preferably 0.001 to 100 parts by mass, more preferably 0.01 to 75 parts by mass, and 0.1 to 50 parts by mass. is most preferred.

The reason why the organic resin solution and the spinning solution of the present invention are excellent in stability is not completely clear, but the amide of a urea-based compound is used for the chemical structure portion in which a highly reactive nitrogen atom exists in the organic resin. This is believed to be due to the fact that the affinity of the structural portion makes it difficult for undesirable reactions (such as insolubilization in the solvent) that lead to a decrease in stability such as self-crosslinking of the organic resin in the solvent to proceed. .

In particular, this effect is attributed to polybenzimidazole, which has many nitrogen atoms in its chemical structure (because it has many nitrogen atoms in its chemical structure, undesired reactions such as self-crosslinking that reduce stability are likely to proceed). It is effectively exhibited in an organic resin solution or spinning solution containing an organic resin such as. In addition, this effect is obtained by using an organic resin solution containing a urea-based compound such as urea, which has a low molecular weight (it is believed that it has a higher affinity with the chemical structure portion having a nitrogen atom of the organic resin due to its small molecular structure), or spinning. Works effectively in liquids.

The organic resin solution and spinning solution according to the present invention may contain other organic resins and various additives as required.
Other types of organic resins can be appropriately selected, but for example, polyolefin resins (e.g., polyethylene, polypropylene, polymethylpentene, polyolefins having a structure in which a portion of the hydrocarbon is substituted with a cyano group or a halogen such as fluorine or chlorine) resin, etc.), styrene resin, polyvinyl alcohol resin, polyether resin (e.g., polyether ether ketone, polyacetal, modified polyphenylene ether, aromatic polyether ketone, etc.), polyester resin (e.g., polyethylene terephthalate, poly trimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, polyarylate, wholly aromatic polyester resin, etc.), polyimide resin, polyamideimide resin, polyamide resin (e.g., aromatic polyamide resin, aromatic group polyetheramide resin, nylon resin, etc.), resins with nitrile groups (e.g., polyacrylonitrile, etc.), urethane-based resins, epoxy-based resins, polysulfone-based resins (e.g., polysulfone, polyethersulfone, etc.), fluorine-based resins (e.g., polytetrafluoroethylene, polyvinylidene fluoride, etc.), cellulose resins, polybenzimidazole resins, acrylic resins (e.g., polyacrylonitrile resins obtained by copolymerizing acrylic acid esters or methacrylic acid esters, acrylonitrile and vinyl chloride) or a modacrylic resin obtained by copolymerizing vinylidene chloride, etc.) can be used alone or as a mixture of a plurality of types of known organic resins.
The mass of the organic resin solution or the other organic resin contained in the spinning solution can be appropriately selected according to the preparation conditions of the material such as spinning conditions so as to provide the desired material.

In addition, the types of various additives can be appropriately selected. Inorganic particles, inorganic fillers, activated carbon, charcoal black, spinning stabilizers, etc. can be added. The type of spinning stabilizer can be selected as appropriate. It can be used singly or as a mixture of multiple types.

In addition, the mass of various additives contained in the organic resin solution or the spinning solution is appropriately selected according to the preparation conditions of the material such as spinning conditions so as to provide the desired material. Specifically, when the mass of the organic resin solution or spinning solution is 100 parts, it can be present in an amount of 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, and 1 to 10 parts by mass. parts by mass can be present.

The temperature and viscosity of the organic resin solution and the spinning solution are appropriately selected according to the preparation conditions of the material such as the spinning conditions so that the desired material can be provided. Specifically, the temperature of the organic resin solution or the spinning solution can be 0 to 165°C, can be 10 to 160°C, and can be 20 to 150°C. Also, the viscosity of the organic resin solution or the spinning solution at 25° C. can be 10 to 30000 mPa·s, can be 100 to 20000 mPa·s, and can be 1000 to 10000 mPa·s.

Next, a method for producing a fiber assembly using the spinning solution according to the present invention will be illustrated and explained. Note that the description of items that have the same configuration as those already described will be omitted.

The method for producing the fiber assembly can be selected as appropriate. Examples include an electrostatic spinning method, a method of spinning by the action of gas as disclosed in JP-A-2009-287138, and a method disclosed in JP-A-2011-32593. In addition to the action of an electric field as described above, a method of spinning by applying a shearing force of a gas, a centrifugal spinning method, or the like can be used. Then, a method for producing a fiber aggregate comprising a step of reducing the diameter of the spinning solution by using these production methods, forming fibers, and collecting them on a collector such as a drum or a net can be used.
Among these, by using the electrostatic spinning method and the method of spinning by gas shearing action as disclosed in JP-A-2009-287138, ultrafine fibers having an average fiber diameter of 2 μm or less can be easily spun, This is suitable because it facilitates the production of a fiber aggregate composed of continuous ultrafine fibers having uniform fiber diameters.

The method for reducing the diameter of the spinning solution can be selected as appropriate. For example, by applying an electric force to the spinning solution discharged from a nozzle or slit based on the electrostatic spinning method, the discharged spinning solution is directed toward the counter electrode. A method in which the spinning solution is jetted to reduce the diameter, and a method in which a gas force is applied to the spinning solution discharged from a nozzle or a slit to cause the discharged spinning solution to fly toward a collector such as a mesh to reduce the diameter. can be adopted.
Then, the spinning solution that has been reduced in diameter (fiberized) as described above is collected on a collecting body such as a mesh or a belt conveyor to form a fiber web on the collecting body.

The fibrous web thus produced can be used as it is as a fibrous assembly, or it may be subjected to a heating device in order to remove the solvent and the urea-based compound from the fibrous web. The type of heating device can be appropriately selected, and for example, a device that heats or pressurizes with a roll, an oven dryer, a far-infrared heater, a dry heat dryer, a hot air dryer, a device that can irradiate and heat with infrared rays, etc. can be used. The heating temperature of the fibrous web by the heating device is appropriately selected, but the temperature should be such that the solvent and the urea-based compound can be volatilized or decomposed and volatilized, and the constituent components such as the constituent fibers will not unintentionally decompose or denature. Adjust accordingly.
If necessary, the organic resin contained in the constituent fibers may be self-crosslinked or crosslinked by heating with a heating device. Specifically, by heating a fiber web having constituent fibers containing polybenzimidazole at a temperature of 350° C. or higher, a fiber aggregate having excellent solvent resistance can be provided.

Alternatively, the fiber web or fiber aggregate produced as described above may be immersed in water or the like to elute and remove the solvent and urea-based compound remaining in the constituent fibers.
Further, the fibrous web or fibrous aggregate produced as described above may be subjected to a pressure treatment process, such as a reliant press treatment, in order to smoothen the surface.

The fiber assembly thus produced may be used as it is for various purposes, but it may be used in a step of forming a composite with a resin film, or by laminating another constituent member such as a porous body, film, or foam. Through various secondary processes such as the process of manufacturing the body, and the process of processing by punching out a shape according to the application and usage mode, materials with fiber aggregates that can be used as various industrial materials are prepared. may

A film or composite comprising an organic resin containing a nitrogen atom in its chemical structure can be produced by subjecting an organic resin solution to a conventionally known method for producing a film or composite.

Specifically, it is possible to employ a film manufacturing method comprising a step of spreading the organic resin solution according to the present invention into a sheet, and then removing the solvent from the organic resin solution spread into the sheet. The thickness of the film to be produced can be selected as desired, and the film may be either a non-breathable film or a breathable film. Alternatively, it may be a foamed film.

Further, the organic resin film is provided on the surface of the object to be coated, which comprises the step of applying the organic resin solution according to the present invention to the object to be coated and then removing the solvent from the organic resin solution applied to the object to be coated. Composite manufacturing methods can be employed. The type of object to be coated and the thickness of the organic resin coating in the composite can be selected as desired.
The remaining solvent and urea-based compound can be removed from the film or composite in the same manner as the method for removing the remaining solvent and urea-based compound from the fiber assembly described above.

Similarly, the produced film or composite may be used for various purposes as it is, but the process of forming a composite with a resin film, or laminating other constituent members such as porous bodies, films, foams, etc. After undergoing various secondary processes such as the manufacturing process and the process of processing such as punching out shapes according to the application and mode of use, materials with films and composites that can be used as various industrial materials are prepared. may

EXAMPLES The present invention will be specifically described below with reference to Examples, but these are not intended to limit the scope of the present invention. Examples 7 to 10 are examples of the present invention, and Examples 1 to 6 and 11 are reference examples.

(Comparative example 1)
After mixing 75 parts by mass of dimethylacetamide and 25 parts by mass of polybenzimidazole (manufactured by Performance Products, model number: CELAZOLE (registered trademark), PBI 100 Mesh Polymer), the mixture was heated to 150 ° C. to convert poly to dimethylacetamide. A solution was prepared by dissolving benzimidazole.
The prepared solution was cooled to 25° C., passed through a glass filter with a pore size of 1 μm (manufactured by Advantech, model number: GA-100) and filtered to prepare an organic resin solution.

(Example 1)
After mixing 75 parts by mass of dimethylacetamide and 25 parts by mass of polybenzimidazole (manufactured by Performance Products, model number: CELAZOLE (registered trademark), PBI 100 Mesh Polymer), the mixture was heated to 150 ° C. to convert poly to dimethylacetamide. A solution was prepared by dissolving benzimidazole.
After cooling the prepared solution to 80 ° C., 0.25 parts by mass of urea (manufactured by Tokyo Kasei Chemical Industry Co., Ltd.) was mixed and dissolved, then the solution was cooled to 25 ° C. and passed through a glass filter with a pore size of 1 μm ( An organic resin solution was prepared by passing through Advantech, model number: GA-100) and filtering.

(Example 2)
An organic resin solution was prepared in the same manner as in Example 1, except that the mass of urea to be dissolved was changed to 0.5 parts by mass.

(Example 3)
An organic resin solution was prepared in the same manner as in Example 1, except that the mass of urea to be dissolved was changed to 0.75 parts by mass.

(Example 4)
An organic resin solution was prepared in the same manner as in Example 1, except that the mass of urea to be dissolved was changed to 1.25 parts by mass.

(Example 5)
An organic resin solution was prepared in the same manner as in Example 3, except that the urea-based compound to be dissolved was changed to 0.75 parts by mass of dimethylurea.

(Example 6)
An organic resin solution was prepared in the same manner as in Example 3, except that the urea-based compound to be dissolved was changed to 0.75 parts by mass of phenylurea.

The stability of each organic resin solution was evaluated by subjecting each organic resin solution prepared as described above to the following measurement method.

(Confirmation of stability of organic resin solution)
Each organic resin solution prepared as described above was allowed to stand in an environment of 25° C. for 7 days. Then, the number of days until polybenzimidazole precipitated in the organic resin solution was visually confirmed.
As a result of confirmation, precipitation of polybenzimidazole was observed in the organic resin solution of Comparative Example 1 when the organic resin solution was allowed to stand for two days. On the other hand, when the organic resin solution of Example 1 was allowed to stand still for 2 days, no precipitation of polybenzimidazole was observed in the organic resin solution, and after the organic resin solution was allowed to stand for 4 days, precipitation of polybenzimidazole was observed in the organic resin solution. was taken. In addition, when the organic resin solution of Example 2-6 was allowed to stand still for 2 days, precipitation of polybenzimidazole was not observed in the organic resin solution, and polybenzimidazole was not observed in the organic resin solution even after standing for 7 days. No precipitation of benzimidazole was observed.

(Spinning solution and method for producing nonwoven fabric using the spinning solution)
After each organic resin solution of Comparative Example 1 and Examples 1-4 was allowed to stand in an environment of 25 ° C. for 2 days, each organic resin solution (only the organic resin solution of Comparative Example 1, polybenzimidazole in the organic resin solution Precipitation was observed) was used as a spinning solution, and spinning was performed by subjecting it to an electrostatic spinning apparatus under the following conditions to attempt to produce a nonwoven fabric, which is a fiber aggregate.
A grounded power supply was connected to a metal nozzle with an inner diameter of 0.44 mm. A grounded collector (glass cloth impregnated with polytetrafluoroethylene and conductive particles and baked) was provided so as to face the opening at the tip of the nozzle. At this time, the shortest distance between the tip of the nozzle and the collector was adjusted to 7 cm. A power supply applied 5-15 kV to the nozzle to form an electric field between the nozzle and the collector.
The spinning solution is discharged from the opening of the nozzle at a discharge rate of 1 cc/hour, the spinning solution is led to an electric field, and the spinning solution is caused to fly from the opening at the tip of the nozzle to the collecting body and to be reduced in diameter, It was fiberized and collected on a collector to prepare a fiber web. The spinning environment in this process was a temperature of 25° C. and a humidity of 40% RH.
The fiber web thus obtained is heat-treated at 180° C. for 30 minutes using an electric furnace (PHH200 manufactured by TABAI) to volatilize the dimethylacetamide remaining in the fibers constituting the fiber web. (and if the urea-based compound remained in the fibrous web, the urea-based compound was also volatilized) to produce a nonwoven fabric.

(Comparative example 2)
The polybenzimidazole nonwoven fabric produced using the organic resin solution of Comparative Example 1 as a spinning solution after standing for 2 days in an environment of 25° C. contained many non-fiber materials such as shot, and the average fiber The diameter (500 nm) and fiber diameter CV value (0.5) were unintentionally large. In addition, the ejection of the spinning solution from the tip of the nozzle during spinning was unstable, making it difficult to produce a nonwoven fabric.

(Examples 7-10)
The polybenzimidazole non-woven fabrics produced using the respective organic resin solutions of Examples 1-4 as spinning solutions after standing for 2 days in an environment of 25° C. all showed the presence of non-fiber materials such as shot. The average fiber diameter (400 nm) and the CV value of the fiber diameter (0.2) were small. In addition, spinning was possible in a state in which the spinning solution was stably discharged from the tip of the nozzle.

As described above, the organic resin solution according to the present invention and the spinning solution comprising the organic resin solution are excellent in stability, and by using the spinning solution, a fiber assembly of a desired mode can be produced.

(Comparative Example 3)
After standing for 2 days in a 25° C. environment, the organic resin solution of Comparative Example 1 (precipitation of polybenzimidazole was observed in the organic resin solution) was applied onto a glass plate using a coater (slit width: 200 μm). It was applied by spreading it in a sheet shape. After that, the organic resin solution spread on the glass plate is subjected to an oven (heating temperature: 140 ° C.) together with the glass plate to remove dimethylacetamide from the organic resin solution spread on the glass plate surface. A composite with a polybenzimidazole coating (polybenzimidazole coating thickness: 20 μm) was produced. Then, a polybenzimidazole film (thickness: 20 μm) was produced by peeling the polybenzimidazole coating from the glass plate.
When the main surface of the polybenzimidazole coating and the main surface of the film in the composite thus produced were visually confirmed, uneven portions were formed and the appearance was poor.

(Example 11)
After standing for 2 days in a 25° C. environment, the organic resin solution of Example 1 (no deposition of polybenzimidazole was observed in the organic resin solution) was applied onto a glass plate with a coater (slit width: 200 μm). It was applied by using and developing in a sheet form. After that, the organic resin solution spread on the glass plate is subjected to an oven (heating temperature: 140 ° C.) together with the glass plate to remove dimethylacetamide and urea from the organic resin solution spread on the glass plate. A composite with a polybenzimidazole coating on the surface (polybenzimidazole coating thickness: 20 μm) was produced. Then, a polybenzimidazole film (thickness: 20 μm) was produced by peeling the polybenzimidazole coating from the glass plate.
When the main surface of the polybenzimidazole coating and the main surface of the film in the composite thus produced were visually confirmed, no unevenness was found and the appearance was good.

As described above, by using the organic resin solution according to the present invention, it is possible to prevent the presence of uneven portions such as uneven portions and portions with locally different physical properties such as rigidity, thereby achieving a desired form of the film. and composites can be produced.

By the organic resin solution and the spinning solution of the present invention, the method for producing a fiber assembly using the spinning solution, and the method for producing a film and a composite using the organic resin solution, for example, an air filter, a liquid filter, an alkaline Electrochemical device separators for batteries, lithium batteries, capacitors, etc., water treatment membranes, gas separation membranes, electrolyte membranes, supports for various membranes such as the above-mentioned membranes, gas diffusers, masks and adhesive medicinal substrates, etc. We can provide materials that can be used as various industrial materials such as sanitary materials and sound absorbing materials.

Claims (2)

A spinning solution consisting of an organic resin solution containing urea and polybenzimidazole as an organic resin, which is made into fibers by the action of electrostatic force, and is collected on the collecting body by A spinning solution used to form a fibrous web in a A fiber assembly comprising a step of reducing the diameter of the spinning solution according to claim 1 by the action of electrostatic force, converting it into fibers, and collecting the spinning solution on a collector to form a fiber web on the collector. manufacturing method.