JP5551905B2 - Apparatus and method for producing sheet containing fine fibers - Google Patents

Description

  The present invention relates to a manufacturing apparatus for continuously producing a sheet material having a very fine structure composed of fine fibers, and a method of manufacturing a sheet including fine fibers using the apparatus.

In recent years, a sheet material containing fine fibers (hereinafter also referred to as “sheet material” or simply “sheet”) has attracted attention as a novel functional sheet having a nanonetwork structure (for example, Patent Document 1 below). 2).
Such sheet materials are expected to be applied in various fields such as separators for power storage devices, functional filters, and medical materials (see Patent Documents 2 and 3 and Non-Patent Document 1 below). As a method for producing a sheet material, an electrospinning method is widely known (for example, refer to Non-Patent Documents 1 and 2), but film formation by a papermaking method has also been reported (hereinafter, Patent Documents 1 to 3). reference).

  In the film formation by the papermaking method, compared to the electrospinning method, when using a raw material that is easily refined, such as cellulose fiber, a sheet containing finer fibers or a sheet consisting only of fine fibers is low-cost, Furthermore, it becomes possible to manufacture with high productivity. According to the following Patent Document 1, it is possible to obtain a fine fiber having a fiber diameter of 1 μm or less relatively easily by refining a pulp, particularly in cellulose fiber. A sheet containing fine fibers can be satisfactorily obtained by film formation by a papermaking method.

International Publication 2006/004012 Pamphlet JP 2008-274525 A JP 2006-49797 A

Y. Yamashita, Nonwovens Review, 17, 41 (2007) Yoshinori Kishimoto, Journal of the Textile Machinery Society, 61, 49 (2008)

  In forming a film from a short fiber by a papermaking method, when the fiber becomes fine, fineness of a filter belt called a wire used in the papermaking method is also required. Patent Document 1 discloses a technique in which a filter cloth that satisfies a certain requirement wound in a roll shape is placed on a wire during papermaking and is run, and papermaking is performed on the filter cloth.

In this method, after the fine fibers are formed into a film on the filter cloth, it is necessary to peel off the wet paper or a dry sheet obtained by drying the wet paper from the filter cloth and wind the filter cloth itself. There is a restriction that the sheet cannot be made longer than the length of the filter cloth unless it is processed into an endless shape.
In addition, when using a filter cloth wound in a roll shape, if the thickness of the filter cloth is too thick, the drainage resistance increases, and the operability when replacing the roll becomes significantly disadvantageous. It is preferable to use a filter cloth. However, if the filter cloth wound up in roll form is not reused after the paper film is formed, it is not only extremely disadvantageous in terms of cost, but if the filter cloth is reused several times, its wearability (durability) ) Is also an anxiety factor.

  Usually, the paper-making film wire is a metal wire or plastic (woven fabric) wire that is endless processed, and the paper-formed film is transported to an independent press process or drying process. By doing so, a sheet having a length corresponding to the operation time can be continuously produced.

  In this case, it is desirable that the endless processing is not one in which the ends of the wires are joined. This is because when the ends of the wire are joined to form an endless structure, the structure of the wire joint is usually disturbed and the film is formed by a papermaking method from a dispersion containing fine fibers. In the case, there is a high possibility that fine fibers will fall out from the minute holes of the seam. Even if it is a case where the fine joining process of the level which a fine fiber does not fall out is given, it is difficult to make a part with the same drainage resistance precisely in parts other than the joint of a wire, and the joint. If there is a part having different drainage resistance in a part of the wire, the sheet part obtained by forming a film at that part has physical properties different from those of the other parts. That is, in the case where the ends of the wire are joined, heterogeneous portions in terms of physical properties appear periodically in the running direction in the obtained sheet film formation.

  In order to prevent this and stably manufacture the sheet material, it is desirable to use an endless processed wire (hereinafter also referred to as “endless wire”) that does not have a joint. However, as described in Patent Document 1, in order to form a fine fiber having a maximum fiber diameter of 1500 nm or less by a papermaking method, a wire with a very small pore size is required, and in particular, the fiber diameter When becomes small, there are many cases where fibers are fallen off in a commonly used wire for papermaking. Usually, the wire used for papermaking is a metal mesh or a structure in which fibers are appropriately woven in the vertical and horizontal directions, and these are used to make the above fine fibers in high yield ( Filtration) was nearly impossible. Even if a wire with a fine woven structure that can filter fine fibers is made, it is necessary to reduce the fiber diameter of the fibers that make up the wire. It was difficult.

  That is, in providing a continuous (longable) and homogeneous sheet material (which does not have periodic changes in characteristics due to seams) that includes only fine fibers or includes fine fibers, the sheet material is used in a continuous production process. In order to manufacture at low cost and stably, it has been desired to construct a manufacturing apparatus and a manufacturing method using an endless wire that is capable of papermaking (filtering) fine fibers with a high yield and is seamlessly processed. . Therefore, the problem to be solved by the present invention is to provide a manufacturing apparatus and a manufacturing method for continuously producing high-quality and stable sheets containing fine fibers.

The present inventors evaluated various types of available wires, and for metal wires and woven plastic wires that have been used in the conventional papermaking process, 1) filtered fine fibers and recovered wet paper sheets with high yield. It was concluded that it was difficult to satisfy the following two points simultaneously: possessing a fine pore structure as much as possible, and 2) being capable of endless processing of the wire.
Therefore, the wire structure was expanded to a sheet having a nonwoven fabric structure, which was not used in the conventional paper-making technique, and the evaluation was made. In general, in a non-woven structure sheet, for example, a bat layer formed by needle punching short fiber bat fibers, the fibers are laminated while being randomly oriented with respect to the sheet surface. When the sheet is used as a wire, the unevenness of the structure tends to directly lead to nonuniform film quality of the sheet material.

  In the present invention, in order to avoid this, the wire has a multi-layered structure including a non-woven fabric layer so that durability and drainage can be ensured, and the fiber diameter of the fibers constituting the outermost layer is made small and fine. As a result of diligent research and experiments to devise efficient fiber-making, it has been found that the above-mentioned problems can be solved by the following means, and the present invention has been completed. It was.

That is, the present invention is as follows.
[1] A manufacturing apparatus for forming a sheet containing fine fibers, in which a multilayered wire subjected to endless processing is mounted as a belt for papermaking, wherein the multilayered wire includes one or more base layers and one or more layers It is made of a bat layer, one or more layers of the bat layer contain a hot-melt fiber containing a hot-melt resin, and the multilayered wire is heat-treated at a temperature equal to or higher than the melting point of the hot-melt resin. The apparatus characterized by the above.

  [2] The apparatus for producing a sheet containing fine fibers according to [1], wherein the base layer is made of an endless woven fabric, and the batt layer is made of a nonwoven fabric.

  [3] The apparatus for producing a sheet containing fine fibers according to [1] or [2], wherein the average fineness of the batt layer is 6 dtex or less.

  [4] The apparatus for producing a sheet containing fine fibers according to any one of [1] to [3], wherein the hot-melt fiber contains a hot-melt resin having a melting point of 200 ° C. or less.

  [5] The above-mentioned [1] to [4], wherein the hot-melt fiber is a core-sheath composite fiber composed of a core component made of high molecular weight nylon and a sheath component made of nylon having a lower melting point than the core component. ] The manufacturing apparatus of the sheet | seat containing the fine fiber in any one of.

[6] The apparatus for producing a sheet containing fine fibers according to any one of [1] to [5], wherein the air permeability of the multilayered wire is 5 cc / cm ² / sec or less.

  [7] The sheet containing fine fibers according to any one of [1] to [6], wherein the sheet containing fine fibers contains 10% by weight or more of fine fibers having a fiber diameter of 10 nm to 500 nm. manufacturing device.

  [8] The sheet containing fine fibers according to any one of [1] to [7], wherein the sheet containing fine fibers contains 90% by weight or more of fine fibers having a fiber diameter of 10 nm to 500 nm. manufacturing device.

  [9] In any one of the above [1] to [8], in the film forming process by papermaking using the manufacturing apparatus, the yield of fine fibers having a fiber diameter of 10 nm to 500 nm is 90% by weight or more. The manufacturing apparatus of the sheet | seat containing the fine fiber of description.

[10] The following steps:
Using the production apparatus according to any one of [1] to [9] above, from a dispersion in which the proportion of the fine fiber having a fiber diameter of 10 nm to 500 nm in the total solid content is 10% by weight or more. A paper making process for forming a wet paper on the multilayered wire, and a process for conveying the wet paper obtained in the paper making process to any of a pressing process, a drying process, or a solvent replacement process,
A method for producing a sheet containing fine fibers.

[11] The following steps:
Using the production apparatus according to any one of [1] to [9], a dispersion having a ratio of 90% by weight or more in the total solid content of fine fibers having a fiber diameter of 10 nm to 500 nm. From the paper making process of forming the wet paper on the multilayered wire, and the process of transporting the wet paper obtained in the paper making process to any of the pressing process, the drying process or the solvent replacement process,
A method for producing a sheet containing fine fibers.

  By the manufacturing apparatus and manufacturing method of the sheet | seat containing the fine fiber of this invention, the continuous and homogeneous nonwoven fabric sheet which consists of a fine fiber can be provided.

It is the schematic which shows an example of the manufacturing apparatus of this invention, and the apparatus for post processes. It is the schematic which shows the other example of the manufacturing apparatus of this invention, and the apparatus for post processes. It is a cross-sectional schematic diagram of the multilayer wire used for the manufacturing apparatus of this invention. It is a cross-sectional schematic diagram of the other multilayered wire used for the manufacturing apparatus of this invention.

Hereinafter, the present invention will be described in detail.
A first aspect of the production apparatus for a sheet containing fine fibers of the present invention is a production apparatus for forming a sheet containing fine fibers in which a multi-layered wire subjected to endless processing is mounted as a paper film-forming belt, The multilayered wire is composed of one or more base layers and one or more bat layers, and one or more layers of the bat layer contain hot-melt fibers containing a hot-melt resin, and the multilayered wires The apparatus is characterized by being heat-treated at a temperature equal to or higher than the melting point of the molten resin.

  The present invention is an apparatus for producing a sheet containing fine fibers, in which a multi-layered wire subjected to endless processing is mounted as a paper film-forming belt, and the parts other than the paper film-forming belt are industrially used. Any available continuous paper machine can be used. In particular, an inclined wire type paper machine, a long net type paper machine, and a circular net type paper machine can be suitably used as the sheet-forming production apparatus for sheets of the present invention. The manufacturing apparatus may be an apparatus with an improved specification according to the purpose.

  Here, the multi-layered wire needs to be subjected to endless processing for the reason described above. An endless multi-layered wire is an endless rotary belt that is processed so that there is no joint, that is, any part of the multi-layered wire does not include a heterogeneous part associated with joining. Means that. The endless process can be realized by, for example, weaving a woven cloth in an endless manner as a bag weaving when the base layer of the multilayered wire is manufactured.

The multilayered wire is preferably composed of one or more base layers and one or more bat layers.
The base layer preferably functions as a reinforcing layer of the multilayered wire and has a low drainage resistance. Specifically, weaving endlessly with 1/1 plain weave, for example bag weaving, or endless weaving with double weaving such as 3/1 1/3, for example bag weaving. The base layer may be a single layer or a plurality of layers may be laminated.

As the base layer, a woven fabric made of spun yarn or filament, twisted yarn or multifilament made of polyamide fiber or polyester fiber is used, and polyamide single yarn or twisted yarn woven fabric is particularly preferable. As the fineness of the yarn used for the fabric, a yarn material of about 200 to 2000 dtex for single yarn and 400 to 5000 dtex for twisted yarn is used. The basis weight of the entire base layer is appropriately selected from 300 to 800 g / ^{m 2} range of about.

  The vat layer is a layer that functions as a substantial filter when paper making of fine fibers. The batt layer needs to have a fine structure capable of filtering fine fibers, and preferably has durability. The bat layer may be a single layer or a plurality of layers may be laminated.

  For attaching the bat layer to the base layer of the multilayered wire, a fiber lamination technique such as needle punching, electrostatic flocking, spunbonding or spunlace can be used, but the needle punching technique is particularly preferable. In needle punching, short fibers with good crimpability, for example, short fibers having a crimp of about 10-50 threads / 5 cm can be used as the batt layer, so the thickness direction of the base layer compared to other fiber lamination techniques The bat layer can be laminated uniformly and with good entanglement.

The bat layer is a layer in which short fibers are laminated in the thickness direction of the bat layer by entanglement and filters the fine fibers. The smaller the fiber diameter of the fine fibers, the easier it is to penetrate the bat layer. My stay is bad.
Therefore, in the present invention, in order to maintain a high yield of fine fibers, a hot melt fiber is included in the bat layer, and the bat layer is heat-treated to form small pieces that are melted and fixed around the fibers in the bat layer. It is preferable that a high yield of fine fibers is expressed by reducing the pore diameter of the batt layer.

  In the present invention, the average fineness of the bat layer containing the hot-melt fiber is preferably 1 dtex to 6 dtex, more preferably 1 dtex to 4 dtex, and still more preferably 1 dtex to 2 dtex. When the average fineness of the batt layer exceeds 6 dtex, the pore diameter of the batt layer of the multilayered wire cannot be reduced. Therefore, the sheet material made from paper using this multilayered wire has a poor surface smoothness. The quality may not be good. On the other hand, if the average fineness is smaller than 1 dtex, the defibration property in the needle punching process is deteriorated, and the bat layer of the multilayer wire tends to have a non-uniform density, making it impossible to efficiently and uniformly form the paper.

  In the present invention, the content of the hot melt fiber in the batt layer is preferably 1% by weight to 100% by weight, more preferably 5% by weight to 75% by weight, and still more preferably 10% by weight to 50% by weight. The remainder consists of other bat fibers.

  In the present invention, the remaining other batt fibers are preferably fibers having substantially the same fineness as the hot-melt fibers. As a result, a sheet containing fine fibers that can be obtained by a papermaking method using a multilayered wire is improved in surface smoothness, and thus becomes a high-quality sheet. In addition, the larger the content of the hot melt fiber in the batt layer, the smaller the pore diameter of the batt layer, and as a result, the surface smoothness of the sheet obtained by the papermaking method is improved. It becomes worse, papermaking time increases, and sheet production efficiency decreases. On the other hand, the smaller the content of hot-melt fibers in the batt layer, the worse the yield of fine fibers at the time of forming the sheet, and the lower the papermaking efficiency.

In addition, the batt layer may be provided on both sides of the base layer (for convenience, the side in contact with the wet paper made by the multilayered wire is referred to as the “sheet side” and the opposite side is referred to as the “roll side”). the basis weight of each of the batt layer on the sheet side of the base layer 50 to 800 g / ^{m 2,} the roll side of the base layer preferably 0 to 200 g / ^{m 2.} The larger the basis weight of the batt layer, the better the fine fiber yield of the multi-layered wire. However, accumulation of fine fibers inside the batt layer, so-called clogging, may occur. Moreover, when the basic weight of a bat layer is small, durability of a multilayer wire and a fine fiber yield will worsen.

The hot-melt fiber is preferably a fiber containing a hot-melt resin having a melting point of 200 ° C. or lower (hereinafter also referred to as “low melting point component”), and specifically, an aliphatic such as polyethylene or polypropylene having a melting point of 200 ° C. or lower. Examples thereof include polyolefin, or fibers containing a copolymerized polyamide or copolymerized polyester having a melting point of 200 ° C. or lower.
The hot-melt fiber may be a fiber composed of the low melting point component or a fiber partially including the low melting point component. As the latter example, a core-sheath composite fiber having the low melting point component as a sheath and a resin having a higher melting point than the low melting point line segment (also referred to as “high melting point component”) as a core is preferable.
In the present invention, the remaining other batt fibers are fibers made of a hot-melt resin having a melting point higher than 200 ° C., and preferably made of nylon (polyamide), polyester (PET), or aromatic polyamide. Fiber can be used.
The melting point of the heat-melting resin is a melting (endothermic) peak in a profile obtained by using a suitable amount of cut fiber pieces as a sample and raising the temperature by a differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min. It is specified by the rise temperature.

  Furthermore, by heat-treating the multilayered wire used as a papermaking film forming belt in the production apparatus of the present invention, the hot-melt fiber or the core-sheath composite fiber is obtained by bonding small pieces that are melt-fixed around the fiber in the bat layer. It is possible to reduce the pore diameter of the bat layer. That is, in the present invention, since a fine network formed by fibers is formed and held in the batt layer, it is particularly preferable in terms of filtration characteristics (balance between fine fiber filtration characteristics and drainage resistance). In particular, in the present invention, a contact portion of the fiber surface of the heat-melt fiber or the core-sheath composite fiber is fusion-bonded by heat treatment, and can function as a strong knot.

Furthermore, the air permeability of the multilayered wire used as a papermaking film forming belt in the production apparatus of the present invention is 5 cc / cm ² / sec or less, more preferably 3 cc / cm ² / sec or less, more preferably ² cc / When it is cm ² / sec or less, the yield of fine fibers is high, and a sheet containing fine fibers can be produced with high productivity.
Here, the air permeability is an air permeability at a suction pressure of 125 Pa (1.27 cmAq) by a “Fragile Permemeter” air permeability measuring device manufactured by Toyo Seiki based on JIS L1096.

Next, the manufacturing method of the multilayered wire with which the manufacturing apparatus of the present invention is attached will be described.
The multilayered wire of the present invention is, for example,
(1) a step of preparing a base layer, for example, a step of weaving (bag weaving) endlessly;
(2) A step of attaching a bat layer to the sheet side of the base layer, for example, a step of needle punching short fibers;
(3) Preferably, a step of attaching a bat layer to the roll side of the base layer, for example, a step of needle punching a short fiber,
(4) A step of heat-treating the base layer with the batt layer attached thereto, for example, hot air and / or hot press while stretching the base layer between a pair of parallel rolls and rotating the roll to circulate the base layer The process of
And
It is manufactured by the manufacturing method provided.

In the step (1), the warp yarn is placed on a loom and the warp yarn that is moved up and down by the heald and interwoven with the driving yarn that is inherent in the shuttle, thereby weaving endlessly.
In steps (2) and (3), short fibers are preliminarily placed on a card machine and defibrated, and the web is laminated on the sheet side and roll side of the base layer, and then needle punched to entangle the base layer and the bat layer. It will be integrated.
In the step (4), an endless base layer (a base layer provided with a batt layer) is placed between a pair of parallel rolls and heat-treated with hot air and / or hot press rolls in a tensioned state. is there.

The production apparatus of the present invention is intended to stably form a sheet containing fine fibers, and is effective when fine fibers are contained in the raw material for film formation.
In the present invention, the fine fiber means one having a fiber diameter of 1000 nm or less, and the sheet contains fine fibers, or the “sheet containing fine fibers” means 10% by weight or more of the fine fibers in the dry sheet. Including and meaning the sheet.
Further, the fiber diameter means a number average fiber diameter obtained by analyzing from a surface photograph of the dried sheet by a scanning electron microscope.

  The sheet containing fine fibers that can be produced using the production apparatus of the present invention is preferably a sheet containing 10% by weight or more of fine fibers having a fiber diameter of 10 nm to 500 nm, more preferably fibers. A sheet containing 50% by weight or more of fine fibers having a diameter of 10 nm to 500 nm, more preferably 90% by weight or more of fine fibers having a fiber diameter of 10 nm to 500 nm. Using the production apparatus of the present invention, it is possible to form these sheets with high yield and stability. Moreover, if the manufacturing apparatus of this invention is used, it will also become possible to manufacture suitably the sheet | seat which consists only of a fine fiber which is 10 nm or more and 500 nm or less. Even if the dry sheet contains less than 10% by weight of fine fibers, it is possible to form a film using the production apparatus of the present invention. The advantage of the present invention does not necessarily appear because the multilayered wire of the present invention is not used due to the interaction, and the other multilayered wires can form a stable film with a high yield.

  The fine fiber is preferably a short fiber because of the nature of production by papermaking. In recent years, it has been found that the electrospinning method for artificially producing fibers having a fiber diameter of 1000 nm or less or 500 nm or less, or eluting and washing the polymer in the sea region from a composite fiber having a single-thread cross-section with a sea-island structure. Although the method of extracting as a fiber is reported, when using the long fiber manufactured by these methods in this invention, it is preferable to use the short fiber cut into fixed fiber length.

  In the production of a sheet using the production apparatus of the present invention, a more preferable aspect of the fine fiber as the raw material is a fine fiber obtained by a refining treatment from a short fiber having a fine fibril structure. In the case of natural fibers, there are many nanofibers originally called microfibrils, such as cellulose and chitin, which are highly concentrated to form fibers. The fine fiber obtained by performing the refinement | miniaturization process by can be used suitably. In addition, wool, silk, collagen and the like can be used as raw materials for fine fibers as natural fibers. Among these, cellulose fiber is a raw material for fine fibers contained in a sheet produced by the production apparatus of the present invention in that it is extremely versatile and easily available, and can be relatively easily refined to a fiber diameter of 500 nm or less. Can be suitably used.

  As raw materials for fine cellulose fibers, so-called wood pulp and non-wood pulp such as softwood pulp and hardwood pulp can be used. Examples of non-wood pulp include cotton-derived pulp including cotton linter pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp, and straw-derived pulp. Cotton-derived pulp, hemp-derived pulp, bagasse-derived pulp, kenaf-derived pulp, bamboo-derived pulp are cotton lint, cotton linter, hemp-based abaca (for example, many from Ecuador or the Philippines), Zaisal, bagasse, It means a refined pulp obtained by subjecting raw materials such as kenaf and bamboo to a purification process such as delignification by cooking and a bleaching process.

In addition, purified seaweed-derived cellulose and sea squirt cellulose can also be used as raw materials for microfibrillated cellulose. Further, although not microfibrillated cellulose, bacterial cellulose produced by bacteria such as acetic acid bacteria may be used as cellulose microfibrils.
Among these, from the viewpoint of ease of raw material procurement, quality stability, and cellulose purity, it is selected from wood-derived pulp, cotton-derived pulp, hemp-derived pulp, bamboo-derived pulp, bagasse-derived pulp, and kenaf-derived pulp. More preferably, at least one is selected.

  Next, an example of producing fine cellulose fibers by a wet refinement method will be described. For the production of fine cellulose fibers, a high-pressure homogenizer, an ultra-high pressure homogenizer, a grinder or the like can be used. The refinement | miniaturization process using these apparatuses is implemented with respect to the aqueous dispersion of a cellulose fiber. The solid content concentration in the aqueous dispersion (which may contain fibers other than cellulose and filler materials other than fibers as described later) is 0.5% by weight or more and 4% by weight in accordance with the above-described beating treatment. If the solid content concentration is preferably 0.8% by weight or more and 3% by weight or less, more preferably 1.0% by weight or more and 2.5% by weight or less, clogging does not occur and efficient refinement is achieved. Processing can be achieved.

Examples of high-pressure homogenizers used include NS type high-pressure homogenizers from Niro Soabi (Italy), SMT's Lanier type (R model) pressure-type homogenizers, and Sanwa Kikai Co., Ltd. high-pressure homogenizers. Any device other than these devices may be used as long as the device performs miniaturization by a mechanism substantially similar to those of these devices.
Ultra-high pressure homogenizers mean high-pressure collision type miniaturizers such as Mizuho Kogyo Co., Ltd. microfluidizer, Yoshida Kikai Kogyo Co., Ltd. Nanomizer, and Suginoma Machine Co., Ltd. Any device other than these may be used as long as the device can be miniaturized at substantially the same level.
Examples of the grinder-type miniaturization equipment include the pure fine mill of Kurita Machinery Co., Ltd. and the stone mill type grinding machine represented by the supermass colloider of Masuko Sangyo Co., Ltd. Any device other than these devices may be used as long as the device can be miniaturized at the same level.

  The fiber diameter of the refined cellulose fiber is determined based on the conditions for refinement using a high-pressure homogenizer (selection of equipment and operating pressure and number of passes) or pretreatment conditions before the refinement (for example, autoclave treatment, enzyme treatment, beating Control). For example, when a high-pressure homogenizer is used as the refining treatment, the operation pressure is 50 MPa or more, preferably 80 MPa or more, preferably 2 passes or more, more preferably 3 passes or more. A slurry in which fine cellulose fibers as a raw material for a sheet material produced by a production apparatus are dispersed in a solvent such as water can be suitably obtained.

In addition, in the refinement from raw pulp to fine cellulose fibers, the raw pulp can be easily refined by autoclave treatment, beating treatment, enzyme treatment, etc. under impregnation in water at a temperature of 100 ° C. or higher, or a combination thereof. It is effective in some cases to pre-process.
These treatments not only reduce the load of the micronization process, but also discharge impurities components such as lignin and hemicellulose that exist on the surface and gaps of the microfibrils that make up the cellulose fibers to the water phase, resulting in micronization. Since it also has the effect of increasing the α-cellulose purity of the prepared fibers, it may be very effective.

  In the beating treatment step, the raw material pulp is 0.5% by weight to 4% by weight, preferably 0.8% by weight to 3% by weight, more preferably 1.0% by weight to 2.5% by weight. First, fibrillation is promoted to a high degree by a beating device such as a beater or a disc refiner (double disc refiner). When a disc refiner is used, if the clearance between the discs is set as narrow as possible (for example, 0.1 mm or less) and processing is performed, extremely advanced beating (fibrillation) proceeds, so a high-pressure homogenizer or the like is used. The conditions for the miniaturization treatment can be relaxed and may be effective.

  In addition, recycled fibers and synthetic fibers that are not natural fibers can be used as raw materials for the refined fibers. Fibers whose fiber diameter is likely to be 500 nm or less are fibers that are highly oriented in the fiber axis and easily fibrillated. Examples of such fibers include regenerated cellulose fibers such as cupra fibers, lyocell, and tencel, and various polyacrylonitriles. Examples thereof include, but are not limited to, system fibers and para-type aramid fibers. As for the synthetic fiber, the refined fiber can be obtained by following the refinement process of the cellulose fiber in the refinement process. In each step of miniaturization including the pretreatment described above, a plurality of types of fibers may be mixed to perform the treatment.

The raw material of the sheet produced by the production apparatus of the present invention may contain short fibers other than fine fibers, or may be a material other than fibers such as a filler material. In such a case, or when the above-described plural types of fine fibers are mixed, the obtained sheet is a composite sheet.
As short fibers other than fine fibers, short fibers having a fiber diameter larger than 1000 nm obtained from the above-mentioned fine fiber raw fibers (for example, rayon short fibers having an average fiber diameter of 5 μm or wood pulp are fibrillated by a beating process. Fibrillated cellulose fibers (main fibers with a fiber diameter of several μm to 10 μm remain) and short fibers of completely different materials (for example, polyethylene terephthalate (PET) fibers, nylon fibers, polyurethane fibers, polyolefin fibers) , Polyketone fiber, polysulfone fiber, polyvinyl chloride fiber, cellulose diacetate fiber, cellulose triacetate fiber, and the like), and fibers obtained by fibrillating the short fibers by a beating treatment or the like, but are not limited thereto.

  Examples of the filler material include inorganic fibers, inorganic particles, and polymer particles. Examples of the inorganic fibers include fibers that do not dissolve in the dispersion medium described later, and carbon fibers such as carbon nanofibers and carbon nanotubes obtained by firing and carbonizing glass fibers, metal fibers, and polymer fibers. However, it is not limited to these.

  Inorganic particles include silica particles such as fumed silica and colloidal silica, plate-like inorganic particles such as smectite, metal oxide particles such as titanium oxide, alumina, zinc oxide and barium titanate, gold, silver and copper. And metal particles such as iron and nickel. The particle shape may be not only spherical but also whisker-like or other irregularly shaped particles, but is not limited thereto.

  Polymer particles include styrene-butadiene (SB) latex, acrylic latex, various rubber latexes, polyvinylidene chloride latex and urethane latex, as well as polyolefin particles and polymethyl methacrylate. -Based particles, polyamide-based particles, polyester-based particles, wholly aromatic polyamide-based particles, polyimide-based particles, polycarbonate-based particles, cellulose-based particles such as crystalline cellulose, polyacetal-based particles, and the like, but are not limited thereto. .

  Further, the sheet containing fine fibers produced using the production apparatus of the present invention includes an additive such as a water-soluble polymer, a surfactant, and a metal salt introduced in the form of metal ions into the papermaking dispersion. Kinds may also be included. These may not only stabilize the papermaking dispersion but also contribute to improving the quality of the resulting sheet (improving film quality uniformity, improving strength, etc.).

Next, the manufacturing method of the sheet | seat containing the fine fiber using the manufacturing apparatus of this invention is described.
The method for producing a sheet containing fine fibers according to the present invention includes the following steps:
Using the manufacturing apparatus described above, wet paper is formed on the multilayered wire from the dispersion liquid in which the proportion of the fine fibers having a fiber diameter of 10 nm to 500 nm in the total solid content is 10 wt% or more. A step of conveying the wet paper obtained in the paper making step and the paper making step to any of a pressing step, a drying step, or a solvent replacement step;
It is a manufacturing method of the sheet | seat containing a fine fiber containing.

  In the papermaking process, papermaking dispersion is supplied to a papermaking machine equipped with the multi-layered wire that has been subjected to the endless processing described above. As the papermaking dispersion at this time, a dispersion in which the fine fibers are dispersed in a solvent, or a dispersion in which the fine fibers and materials other than the fine fibers are mixed and dispersed in a solvent is used. In any case, the fine fibers may be single type or plural types.

As the solvent, water is usually used, but in some cases, an aqueous solution of an organic solvent that dissolves in water such as ethanol or isobutanol, or an organic solvent that phase-separates into water such as n-decane, n-hexanol, or n-heptanol is included. An O / W type emulsion may be used. When an aqueous solution of an organic solvent is used as the solvent, the weight concentration of the organic solvent dissolved in the aqueous solution is 80% by weight or less, more preferably 50% by weight or less, whereby a sheet containing fine fibers having a fine pore diameter is obtained. It becomes easy to be done. Further, when an O / W type emulsion is used as a solvent, the concentration of the weight of the oil droplets dispersed in the emulsion is 5% by weight or less, more preferably 2% by weight or less. Can be obtained at a lower cost than the production method by organic solvent substitution.
When the proportion of the fine fibers contained in the dispersion in the total solid content is 10% by weight or more, preferably 50% by weight or more, more preferably 90% by weight or more, the production apparatus of the present invention is used to obtain high yield. A sheet containing fine fibers can be formed efficiently and stably.

  In order to obtain a high-quality sheet material from a papermaking dispersion, the dispersion conditions after blending various components are also important. In order to achieve stable and highly efficient papermaking, the total solid concentration in the dispersion is preferably 0.05% by weight to 0.5% by weight, more preferably 0.1% by weight to 0%. .4% by weight or less, more preferably 0.13% by weight or more and 0.3% by weight or less. In addition, the dispersion conditions for preparing the dispersion liquid are such that a sheet with excellent uniformity can be obtained by appropriately performing advanced dispersion treatment using a disper-type disperser, beating machine, high-speed homogenizer, grinder, etc. preferable. In addition, at the time of dispersion, as described in Patent Document 1, a sheet in which the fine fibers are gradually entangled rather than a state in which the individual fine fibers are independently dispersed by advanced dispersion conditions is obtained. Is ideal for both physical properties (improvement of strength due to numerous entanglements) and production (easy to secure a route for water removal during paper making and excellent drainage). It is important to set

  The papermaking dispersion is supplied via the multilayered wire to the papermaking machine equipped with the multilayered wire, which is the production apparatus of the present invention, and film formation by papermaking proceeds on the multilayered wire. In the papermaking process, if pressure reduction control by suction is performed, drainage efficiently proceeds and productivity is improved. A wet paper containing fine fibers is obtained through the paper making process, but the wet paper has a solid content of preferably 5% by weight to 50% by weight, more preferably 8% by weight to 40% by weight. It is preferable because it has a wet paper strength that can be easily transported to the next step. If the solid content of the wet paper is less than 5% by weight, the wet paper strength is weak and undesirably difficult to convey to the next step, while if the solid content of the wet paper is more than 50% by weight, In the paper making process, a powerful pre-drying described later is necessary, and the durability of the multilayered wire mounted on the paper machine is impaired by the pre-drying, which is not preferable.

The sheet containing fine fibers that can be produced by the production method of the present invention (“wet paper” immediately after papermaking) has a very fine network structure, unlike the conventional production process of wet paper made of short fibers. Therefore, liquid retention is high. Therefore, the wet paper may not reach the solid content rate only by filtration using suction or the like. In such a case, it is also effective to provide a pre-press part during the paper making process where the multilayered wire is attached to perform dehydration, or to provide a pre-dry part by a heating roll to improve the solid content rate. However, when the preliminary drying part is provided, it is necessary to set the conditions so as not to adversely affect the durability of the multilayered wire contacting the heating roll by preliminary drying. Specifically, when the surface temperature of the pre-drying roll is preferably set to 100 ° C. or lower, more preferably 60 ° C. or lower, the multilayered wire of the present invention has good dimensional stability and less adverse effects such as thermal deterioration. Become. In addition, when preliminary drying affects the multilayered wire of this invention, it can respond by selecting the material of the short fiber of a base layer or a batt layer suitably.
The wet paper obtained in the above papermaking process is conveyed to at least one of a pressing process, a drying process, and a solvent replacement process. In any case, the conveyance is performed either by simply sending the wet paper to the next process or by contacting or transferring the wet paper. In some cases, a method of once transferring and picking up a press roll in the preliminary press part in the paper making process is also effective.

  The pressing step is effective for improving the wet paper strength by further dehydration or controlling the wet paper thickness. The drying process is preferably performed by a drying method that can reduce drying shrinkage such as a drum dryer. However, even when the composition of the sheet does not contain or includes fibers with extremely large drying shrinkage such as fine cellulose fibers, the drying process can be performed accordingly. If the rate is relatively small, and if the wet paper solid content is 30% by weight or more due to preliminary drying in the papermaking process, drying with a continuous hot air dryer or continuous infrared dryer is also effective. is there.

  Furthermore, as seen in the aggregate of fine cellulose fibers, in the production of a sheet containing fine fibers having a large drying shrinkage, in order to obtain a sheet having high porosity and air permeability, The medium, water, is transported to an organic solvent with a lower surface tension (for example, ethyl alcohol, isopropanol, ethyl cellosolve, methyl ethyl ketone, etc.) or a mixed solution of organic solvent / water. It is also effective in some cases to produce a sheet by drying the solvent.

  Anyway, after manufacturing the sheet | seat (wet paper) containing a fine fiber by the paper making process using the manufacturing method of this invention, a wet paper is turned into at least any one process of a press process, a drying process, and a solvent substitution process. In both cases, the sheet is conveyed and processed, and finally the sheet is dried by a drying process and wound. Depending on the product requirements, in some cases, a calendar process including a heating calendar process, a slit process, and the like are performed to obtain a product.

1 and 2 show examples of the production apparatus and the post-process apparatus of the present invention for producing a sheet containing fine fibers.
In the example of FIG. 1, a multi-layered wire A21 subjected to endless processing is attached to the paper making process A10 of the inclined wire type paper machine. The papermaking dispersion is supplied from the supply part A22, forms a liquid pool, and is gradually dehydrated by the reduced pressure dehydrator of the wet suction part A23 as the wire travels to form wet paper. The wet paper is further dehydrated by the dry suction part A24, and then further dehydrated by the press treatment by the press roll A25 installed in the paper making process A10. At the same time, the wet paper is transferred and picked up on the press roll surface. The wet paper picked up from the paper making process A10 is transferred again to the press A11 including the press roll A27, further dehydrated, and sent to the dryer A12. In the dryer A12, the wet paper is combined with the felt layer A28 and comes into contact with the drum dryer A29 to form a dry sheet. The dried sheet obtained through the drying step A is wound up in a roll by a winder A13.

  In the example of FIG. 2, similarly to FIG. 1, a multilayered wire A <b> 21 that has been subjected to endless processing in the paper making process A <b> 10 of the inclined wire type paper machine is mounted. The papermaking dispersion is supplied from the supply part A22, and the wet paper is formed through dehydration by the wet suction part A23 and the dry suction part A24 as in the example of FIG. Thereafter, the solid content rate in the wet paper is increased by the pre-drying roll A30, and the wet paper is made self-supporting and conveyed to the dryer A12. In the drying process, the wet paper is combined with the felt layer A28 and contacts the drum dryer A29 to form a dry sheet. The dried sheet obtained through the drying process is thinned through the calendar processing machine A14 and simultaneously improved in surface smoothness, and is wound up in a roll by the winder A13. The example of the manufacturing apparatus shown in FIGS. 1 and 2 is an example of the embodiment of the present invention, and is not limited to these.

  The sheet material provided by the production apparatus and production method of the present invention is produced as a specification according to the purpose of use, and various functionalities such as separators for various power storage devices, liquid filters, water treatment membranes, and air filters. Not only can it be used as a filter, medical separation filter, wiping sheet for daily products, various functional papers, absorbent materials, and support materials for medical materials, it can also be combined with various resins such as epoxy resins. Thus, it can be used in a wide range of fields, such as substrates for semiconductor devices and wiring boards, and flexible base materials of low linear expansion coefficient materials.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples.
(Examples 1 and 2)
The sheet | seat containing a fine fiber was produced with the sheet | seat manufacturing apparatus shown in FIG. 1 containing the inclination wire type paper machine equipped with multilayered wire B10 which has the structure shown in FIG.

(1) Production of Multilayered Wire As shown in FIG. 3, the multilayered wire B10 includes a base layer B30 made of woven fabric, a first butt layer B22 formed on the sheet side surface of the base layer, and a roll side (base layer). The second butt layer B23 formed on the surface opposite to the sheet side) and the sheet contact side butt layer B21 disposed on the sheet side surface of the first butt layer.
The base layer B30 was woven in a 1/1 structure with six yarns of 360 dtex 6 nylon monofilaments twisted as warps and four yarns of 360 dtex 6 nylon monofilaments single yarn as wefts. The basis weight of the base layer is 350 g / m ² .
The base layer B30 is a 1/1 plain weave woven fabric in FIG. 3, but may be a multiple woven fabric. As materials for the warp and weft of the woven fabric, nylon, polyester (PET), aromatic polyamide, polyparafinylene sulfide (PPS) and the like can be appropriately selected and used.

The batt layers B21, B22, B23 formed on the sheet side or roll side of the base layer B30 are composed of nylon short fibers (staple fibers) and nylon hot-melt fibers (core-sheath composite fibers). It is intertwined and integrated with the sheet side and the roll side of the base layer B30.
Table 1 below shows the basis weight of each bat layer, the average fineness of short fibers, the content of core-sheath composite fibers in the bat layer, and the like.

  The core-sheath composite fiber used has a thickness of 3.3 dtex. However, the core-sheath fiber of the present invention has a core component (melting point: 225 ° C.) made of high molecular weight nylon having an absolute viscosity of 80 mPa · s or more at a temperature of 25 ° C. And a sheath component (melting point: 140 ° C.) made of nylon (for example, copolymer nylon) having a melting point lower than that of the core component.

Bent layers of B21, B22, and B23 are entangled with an endlessly woven base layer B30 by a needle punch, and then placed in a high-pressure press dryer equipped with a heater and a roll press device between two rolls. A multilayered wire B10-MW1 pressed at −2 m / min at 20 Kg / cm and a multilayered wire B10-MW2 pressed at 140 ° C. at 2 m / min at 40 Kg / cm were produced. 140 ° C.-20 Kg / cm product has air permeability 4.3 cc / cm ² / sec, surface smoothness Ra = 5.4 μm, 140 ° C.-40 Kg / cm product has air permeability 1.8 cc / cm ² / sec, surface Smoothness Ra = 4.5 μm was obtained.

  The surface smoothness is the surface smoothness at an evaluation length of 10 mm, a cut-off value of 2.5 mm, and a measurement speed of 0.6 mm / sec by a “Surfcom” surface roughness measuring machine manufactured by Tokyo Seimitsu based on JIS B0601-2001. .

(2) Preparation of dispersion for papermaking Cotton linter pulp (Nippon Paper Pulp Co., Ltd.) was used as a raw material for fine fibers to prepare a fine fiber dispersion. The pulp is dispersed in water to a solid content of 1.5% by weight to form an aqueous dispersion (400 L), and a SDR14 type laboratory refiner (pressurized DISK type) manufactured by Aikawa Tekko Co., Ltd. is used as a beating device. The beating treatment was continued for 20 minutes for 400 L of the aqueous dispersion with a clearance of 1 mm in between, and then the beating treatment was continued for 20 minutes under the condition that the clearance was reduced to almost zero. A uniform and viscous white beating slurry was obtained. The obtained beating slurry was subjected to refinement treatment 5 times under an operating pressure of 100 MPa using a high-pressure homogenizer (NS3015H manufactured by Niro Soabi (Italy)) as it is, and fine cellulose fibers having a number average fiber diameter of 102 μm Aqueous dispersion (solid content concentration: 1.5% by weight), M1.

  Next, Twaron pulp 1094 (Teijin Techno Products Co., Ltd.), which is a para-aramid fiber, was used as a raw material for fine fibers to prepare a fine fiber dispersion. The pulp is dispersed in water to a solid content of 1.5% by weight to obtain an aqueous dispersion (400 L), and the same beating apparatus as in the case of the cotton linter pulp is used. After the beating treatment for 20 minutes was performed on the aqueous dispersion, the beating treatment was continued for 40 minutes under the condition that the clearance was reduced to almost zero, and the white beating slurry slightly yellowish. Got. The beating slurry was refined 10 times using the high-pressure homogenizer under an operating pressure of 100 MPa, and an aqueous dispersion of fine aramid fibers having a number average fiber diameter of 187 μm (solid content concentration: 1.5 weight) %), M2 was obtained.

  When only M1 is diluted with water and when M1 and M2 are diluted with water at a weight ratio of 1: 1, the total solid content concentration in the dispersion is 0.2% by weight. To make papermaking dispersions D1 and D2, respectively. That is, D1 was a 0.2 wt% aqueous dispersion of fine cellulose fibers, and D2 was a mixed aqueous dispersion of fine cellulose fibers / fine aramid fibers = 0.1 / 0.1 (wt% / wt%). Both dispersions were prepared for a total amount of 400 L, and after the preparation of the composition by dilution or the like, the above-described beating apparatus was used as a dispersing apparatus, and the treatment was performed for 20 minutes with the distance between the disks set to zero to obtain a papermaking dispersion.

(3) Continuous film formation by a paper machine When each of the multi-layered wires B10-MW1 and B10-MW2 subjected to the endless processing is mounted in the paper making process A10 of the inclined wire type paper machine shown in FIG. And Example 2), sheet-forming properties when using papermaking dispersions D1 and D2 and physical properties of the obtained sheets were evaluated.

Here, the specifications of the papermaking process and the conditions for papermaking were as follows:
Width of paper making part in paper making process: 0.65m,
Papermaking part length (wet suction line length): 1.8m,
Inclination angle of papermaking part: 5 °,
Feed rate of the papermaking dispersion to the papermaking process: 32.5 L / min,
Wire traveling speed: 10 m / min,
(The target weight is 10 g / m ² from the relationship between the concentration of the dispersion, the supply speed, and the traveling speed of the wire).

  The wet suction and dry suction settings are controlled as appropriate during the paper making process, and the wet paper is transferred to the press roll A25 using the pressure of the press roll A25 as appropriate. Then, the paper was further press dehydrated, and then the wet paper was dried with a drum dryer A29 set at a surface temperature of 130 ° C. and wound into a roll with a winder.

  The film forming properties from the papermaking dispersions D1 and D2 in Examples 1 and 2 and the physical properties of the obtained sheets are shown in Table 2 below:

In Example 1, from D1 composed of finer fibers, fibers were lost in the papermaking process, and film formation by papermaking was not possible. However, when the papermaking dispersion D2 was used, from the wire Although the transferability (peelability) of the wet paper was slightly poor, it was confirmed that film formation by papermaking was possible. From the basis weight of the obtained sheet, the yield was also good.
On the other hand, in Example 2, film formation was possible also from D1, which could not be formed by papermaking in Example 1. However, the transferability (peelability) of the wet paper from the wire was not good, the basis weight of the obtained sheet was slightly low, and it was found that there was a slight loss of fine fibers during papermaking or transfer. Further, the amount of liquid pool in the supply part repeatedly increased and decreased over time, and stable papermaking was difficult. On the other hand, when D2 was used, both the paper-making property and transferability were good, the yield was also good, and the sheet physical properties were also better than the results in Example 1 using the same D2. . That is, it was possible to form a sheet made of fine fibers with a device equipped with the multilayered wire B10-MW2 having a low air permeability.

(Example 3)
The sheet | seat containing a fine fiber was produced with the sheet | seat manufacturing apparatus shown in FIG. 1 containing the inclination wire-type paper machine equipped with multilayered wire B11 which has the structure shown in FIG.
As the papermaking dispersion, D1 and D2 used in Examples 1 and 2 were used, and papermaking was performed under the same conditions.

The multilayered wire B11 was produced as follows.
In FIG. 4, a single woven fabric, a yarn obtained by twisting four 6 nylon monofilament monofilaments of 240 dtex, and a warp yarn, and a 600 dtex 6 nylon monofilament monofilament yarn were weaved in a 1/1 structure. The basis weight of the base layer is 200 g / m ² .
Further, in FIG. 4, a double woven fabric, a yarn obtained by twisting 6 single nylon monofilament yarns of 240 dtex, warp yarn, a yarn obtained by twisting 4 single nylon monofilament yarns of 360 dtex, and a weft yarn, 3/1-1/3 structure Weaved with. The basis weight of the base layer is 450 g / m ² .
As shown in FIG. 4, on the base layer B30, the base layer B30 is an endless base layer formed by stacking the sheet side first base layer B30a (single woven fabric in FIG. 4) and the roll side second base layer B30b (double woven fabric in FIG. 4). The sheet contact side butt layer B21 has a two-layer structure of a sheet contact side first butt layer B21a and a sheet contact side second butt layer B21b adjacent to the sheet side first butt layer B22. From the press side B22 toward the sheet side B21a, the content of the core-sheath composite fiber was increased stepwise. Thereby, the fineness difference between each bat layer decreased, and a smoother surface property was obtained. Furthermore, the roll-side second batt layer B23 reduced the content of the core-sheath composite fiber, and improved the soil dischargeability.
Table 3 below shows the basis weight of each bat layer, the average fineness of short fibers, the content of core-sheath composite fibers in the bat layer, and the like.

Batts of B21a, B21b, B22, and B23 are intertwined with endless woven base layers B30a and B30b with a needle punch, and then applied to a high-pressure press dryer equipped with a heater and a roll press device between two rolls. The multilayered wire B11-MW was manufactured by pressing at 40 Kg / cm at 140 ° C.-2 m / min.
The double woven fabric of the base layer B30b improves the overall compression recovery by thickness and cushioning, and the warp and weft of each of the sheet side first base layer 30a and the roll side second base layer 30b are 2.5 in a single weave. Doubled to improve the adhesion between the bat layer and the base layer and improve the wear resistance. That is, 134% improvement in thickness retention was confirmed compared to Example 1. The air permeability was 1.5 cc / m ² / sec, and the surface smoothness Ra was 3.6 μm.
In addition, thickness retention is a value defined by the thickness after the test when the thickness before the test is 100% when a flattening test is performed 100,000 times at a load of 15 MPa at 10 Hz.

  The multilayered wire B11-MW was mounted on the paper machine shown in FIG. 1 in the same manner as in Example 1, and the paper film was formed from the papermaking dispersions D1 and D2. Table 2 shows the film-forming properties from the papermaking dispersions D1 and D2 in Example 3 and the physical properties of the obtained sheet. From Table 2, the paper machine equipped with the multilayered wire B11-MW is excellent from the viewpoints of both paper-making properties and transferability from the wet paper wire, regardless of whether the dispersion liquid of D1 or D2 is used. There was found. It goes without saying that the physical properties of the obtained sheet are also good in yield, and that it is possible to obtain a sheet better than that of Example 2 in terms of physical properties (constant air resistance and high strength).

(Comparative Example 1)
Among the commercially available woven endless wires, LTT-9FE (Nippon Filcon Co., Ltd.) (denoted as FW) having a very fine woven structure is mounted on the same paper machine as in Example 1, and Example 1 In the same manner as described above, the papermaking film was formed using the dispersions D1 and D2 for papermaking.
As a result, it was found that the papermaking from D1 was impossible because no wet paper remained on the wire. Also, in the papermaking from D2, a thin wet paper remains on the wire for a while after the start of the papermaking experiment, but the amount of liquid pool in the supply part increases over time, and fiber clogging is in the wire. It was estimated that it occurred. Even if the suction conditions were changed, the situation could not be improved. That is, it was not possible to carry out film formation by papermaking from both the D1 and D2 dispersions. The results are shown in Table 4 below.

(Comparative Example 2)
Next, in the multilayered wire according to the present invention, a multilayered wire (denoted as SW) is prepared, and the SW wire is attached to the paper machine shown in FIG. Papermaking film formation was performed using dispersions D1 and D2 for papermaking.
The multilayer wire SW was produced as follows. That is, in Example 2, the bat layer was a bat layer made of only high molecular weight nylon (melting point 225 ° C.), and a SW wire was manufactured using 400 g / m ^{2 of} short fiber fineness 1.0 dtex staple. The air permeability was 5.3 cc / cm ² / sec, and the surface smoothness Ra was 6.6 μm.
Table 4 below shows the results of paper film formation on a paper machine equipped with SWs D1 and D2.
In film formation by D1, even if the suction pressure was set low, only a small amount of wet paper remained on the wire, and it was determined that papermaking properties were poor. In addition, when the papermaking by D2 was carried out, a continuous wet paper was formed with an extremely weak suction pressure, but the wet paper was not able to be transferred even when the press pressure was set high. It was estimated that many fiber bites occurred. That is, it was not possible to carry out film formation by paper making from either D1 or D2 by a paper machine equipped with SW.

  A sheet material having a fine structure containing fine fibers that can be used as a separator for an electricity storage device, a functional filter, a medical material, and the like by using a manufacturing apparatus for sheet film formation containing fine fibers according to the present invention. High quality and stable continuous production becomes possible.

A10 Papermaking process of inclined wire type paper machine A11 Press machine A12 Dryer A13 Winder A14 Calendar processing machine A21 Multi-layer wire A22 Paper dispersion liquid supply part A23 Wet suction part A24 Dry suction part A25 Press roll A26 Washing part A27 Press Roll A28 Felt layer A29 Drum dryer A30 Pre-drying roll B10 Multilayered wire B11 Multilayered wire B21 Sheet contact side butt layer B21a Sheet contact side first butt layer B21b Sheet contact side second butt layer B22 Sheet side first butt layer B23 Roll Side second butt layer B30 base layer B30a Sheet side first base layer B30b Roll side second base layer

Claims (11)

  A manufacturing apparatus for forming a sheet containing fine fibers in which a multi-layered wire subjected to an endless process is mounted as a paper film-forming belt, the multi-layered wire comprising one or more base layers and one or more bat layers Wherein one or more layers of the batt layer include a hot-melt fiber containing a hot-melt resin, and the multilayered wire is heat-treated at a temperature equal to or higher than the melting point of the hot-melt resin. Said device.   The manufacturing apparatus of the sheet | seat containing the fine fiber of Claim 1 with which the said base layer consists of an endless woven fabric, and the said batt layer consists of a nonwoven fabric. The manufacturing apparatus of the sheet | seat containing the fine fiber of Claim 1 or 2 whose average fineness of the fiber which comprises the said batt layer is 6 dtex or less.   The manufacturing apparatus of the sheet | seat containing the fine fiber of any one of Claims 1-3 in which the said hot melt fiber contains hot melt resin with melting | fusing point of 200 degrees C or less.   5. The core-sheath composite fiber, wherein the hot-melt fiber is a core-sheath composite fiber composed of a core component made of high-molecular-weight nylon and a sheath component made of nylon having a melting point lower than that of the core component. The manufacturing apparatus of the sheet | seat containing the fine fiber of description. The manufacturing apparatus of the sheet | seat containing the fine fiber of any one of Claims 1-5 whose air permeability of the said multilayer wire is 5 cc / cm < ² > / sec or less.   The manufacturing apparatus of the sheet | seat containing the fine fiber of any one of Claims 1-6 in which the sheet | seat containing the said fine fiber contains 10 weight% or more of fine fibers whose fiber diameter is 10 nm or more and 500 nm or less.   The manufacturing apparatus of the sheet | seat containing the fine fiber of any one of Claims 1-7 in which the sheet | seat containing the said fine fiber contains 90 weight% or more of fine fibers whose fiber diameter is 10 nm or more and 500 nm or less.   The fine fiber according to any one of claims 1 to 8, wherein a yield of fine fibers having a fiber diameter of 10 nm or more and 500 nm or less is 90% by weight or more in a film-forming process by papermaking using the production apparatus. Sheet manufacturing apparatus. The following steps:
Using the manufacturing apparatus according to any one of claims 1 to 9, from a dispersion in which the proportion of the fine fiber having a fiber diameter of 10 nm to 500 nm in the total solid content is 10% by weight or more, A paper making process for forming wet paper on the multilayered wire, and a process for transporting the wet paper obtained in the paper making process to any of a pressing process, a drying process, or a solvent replacement process,
A method for producing a sheet containing fine fibers. The following steps:
Using the manufacturing apparatus according to any one of claims 1 to 6, 8, and 9, the proportion of the fine fiber having a fiber diameter of 10 nm to 500 nm in the total solid content is 90% by weight or more. A paper making process for forming a wet paper on the multilayered wire from a certain dispersion, and a process for transporting the wet paper obtained in the paper making process to any of a pressing process, a drying process, or a solvent replacement process,
A method for producing a sheet containing fine fibers.

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