JP2008162098A - Laminated body including chitin-chitosan based material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated body capable of improving the function of a chitin-chitosan based material and having practically sufficient strength. <P>SOLUTION: The laminated body 10 has a nanofiber structural layer 1 which is mainly composed of a nanofiver 1a containing the chitin-chitosan based material as a major component. The nanofiber structural layer 1 is formed into a sheet shape by depositing the nano-fiber 1a in laminae. In the nanofiber 1a, diameter of fiber is formed to be a nanoscale by spinning the chitin-chitosan based material. A support material 2 for supporting the nanofiber structural layer 1 is disposed on both sides of the nanofiber structural layer 1. The clearance between the nonofiber structural layer 1 and respective support materials 2 are bonded by heating under pressure. The nanofiber structural layer 1 is supported by the support material 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laminate including a chitin / chitosan material, and more particularly, to a laminate having a nanofiber layer composed of nanofibers having a chitin / chitosan material as a main component and a fiber diameter of nanoscale.

  There are a wide variety of technologies that use sheet-like members (sheet materials), including separation technologies for highly removing unknown viruses and harmful substances, and development of sheet materials with various functionalities in various fields. Has been actively conducted. In particular, a sheet material using a fiber material typified by a nonwoven fabric is widely used from the viewpoint of moldability and processability (see Non-Patent Document 1).

  In the development of sheet materials, sheet materials using nanofibers with nanoscale fiber diameters are attracting attention. The sheet material using nanofibers has a specific surface area that is significantly larger than that of sheet materials using existing fiber materials (fiber diameter of about 20 to 30 μm). Various functions, such as better particle capture and higher particle recognition, improved recognition by animals and plants (high cell recognition), and reduced pressure loss when passing gases and liquids (low pressure loss) Can be improved. For this reason, development of sheet materials using nanofibers is progressing in many fields such as environment, hygiene, health and medical care (see Non-Patent Document 2).

  On the other hand, chitin / chitosan-based materials are naturally-derived polymer materials and have been found to have various functions such as antibacterial properties, moisture retention, substance adsorption, and biocompatibility. Chitin is a natural polysaccharide having N-acetylglucosamine as a constituent sugar, and is separated and purified by deproteinizing and decalcifying shells of crab, shrimp and the like. Chitosan is a cationic polysaccharide having glucosamine as a constituent sugar, and is produced by deacetylation treatment using chitin as a raw material. It is estimated that 100 billion tons of chitin resources are biosynthesized annually on the earth. With this abundant amount of resources, chitin / chitosan-based materials are being used in various fields. Chitin / chitosan-based materials are used in, for example, wastewater treatment agents, food shelf life improvers, functional food ingredients, textile processing agents, etc., and are friendly to people and the environment (adverse effects such as irritation) Has been attracting attention as a natural material (see Non-Patent Document 3).

  By using such a chitin / chitosan-based material for the sheet material, various functions of chitin and chitosan can be effectively utilized. The present inventors have found that, for example, nanofibers of chitin / chitosan-based materials can be formed by electrospinning, and paying attention to the biocompatibility and bioabsorbability of chitin / chitosan-based materials. A technology related to nanofibers of chitin / chitosan materials for use in materials (medical materials) is disclosed (see Patent Document 1). This nanofiber sheet material exhibits antibacterial properties, biocompatibility, ion exchange performance, etc. of chitin and chitosan, as well as gas and liquid passage due to the porous structure of nanofibers, microfiltration properties, etc. Can also be expected.

JP-A-2005-290610 New development of functional non-woven fabrics (supervised by Akira Hyuga, issued by CMC Publishing Co., Ltd., 2004, ISBN 4-88231-447-9 C3058) Advanced industrial excavation strategy using nanofiber technology (supervised by Tatsuya Motomiya, published by CMC Publishing Co., Ltd., 2004, ISBN4-88231-424-X C3043) Development and application of chitin and chitosan (supervised by Shigehiro Hirano, published by CMC Publishing Co., Ltd., 2004, ISBN 4-88231-432-0 C3058)

  However, since the chitin / chitosan-based material is a naturally-derived polymer material, generally, the strength tends to be small as compared to a tough synthetic polymer material. In addition, since the solvent is instantly evaporated during the spinning process to form nanofibers, the fiber diameter can be reduced to the nanoscale, but in the resulting nanofibers, the chitin and chitosan molecules are not oriented and crystallized. Often not. For this reason, compared with the fiber material of a general purpose synthetic polymer, intensity becomes extremely small. A sheet material using nanofibers of such chitin / chitosan-based material is formed by depositing nanofibers thinly and randomly, but the bonding property between the fibers is not sufficient, and delamination or Damage occurs. For this reason, depending on the application, there is a problem that practically sufficient strength cannot be obtained and the use is remarkably restricted.

  An object of the present invention is to provide a laminate that can improve the function of a chitin / chitosan-based material and has a practically sufficient strength.

  In order to solve the above problems, the present invention provides a nanofiber layer composed of chitin / chitosan-based material as a main component and nanofibers with a nanometer fiber diameter, and disposed on one or both surfaces of the nanofiber layer. And a film material that supports the nanofiber layer.

  In the present invention, the nanofiber layer is provided on one or both sides of the nanofiber layer to support the nanofiber layer, and the nanofiber layer is supported by the film material. Compared with the fact that the use of the material is remarkably restricted, a practically sufficient strength can be ensured, and the nanofiber is mainly composed of chitin / chitosan-based material having antibacterial properties. Since the specific surface area of the nanofibers constituting the fiber layer is increased and the antibacterial property is also increased, the laminate can be applied to various uses.

In this case, if the film material has a pore that allows gas or liquid to pass therethrough, and the pore has a larger pore diameter than the micropore formed by the nanofiber of the nanofiber layer, the gas or liquid of the nanofiber layer Therefore, it can be suitably used for applications involving the passage of gas or liquid. At this time, the density of the nanofiber layer is preferably 0.01 g / cm ³ or more. Moreover, it is preferable that the thickness of a nanofiber layer shall be 10 micrometers or more. The fiber diameter of the nanofiber may be 1000 nm or less. Since the nanofiber layer composed of such nanofibers has a greater antibacterial property than the fiber layer composed of fibers having a fiber diameter of more than 1000 nm, it can also be used for applications requiring antibacterial properties. The film material may be a nonwoven fabric, a woven fabric, a knitted fabric, a fiber net, or a resin film. At this time, the thickness of the film material is preferably 20 mm or less. Moreover, it is preferable that the pore formed in the film material has a pore diameter of 1 nm or more.

  In this case, the film material can be made of a single material or a combination of a plurality of materials selected from polyester, polyethylene, polypropylene, polylactic acid, cotton, rayon, pulp, and derivatives thereof. The chitin / chitosan-based material can be a single or a combination of chitin, chitosan, chitin or chitosan degradation products, and chitin or chitosan derivatives. Such nanofiber layers and film materials are bonded together by one or more adhesive components selected from polyester, polyethylene, polypropylene, polylactic acid, polyvinyl acetate, polyvinyl alcohol, epoxy resin, phenolic resin and starch. May be.

The laminate of the present invention can be applied to various uses. For example, in the cosmetic material applications range of the thickness 10μm~1000μm the nanofiber layer, the range of density of ^{0.01g / cm 3 ~0.5g / cm 3} , a resin film thickness range of 100μm~2000μm the film material, range of the thickness 10μm~1000μm nanofiber layer in regenerative medicine material applications, the range of density of ^{0.01g / cm 3 ~0.5g / cm 3} , the range of thickness 1μm~10mm the film material, the nano in filter applications The fiber layer has a thickness in the range of 10 μm to 1000 μm, the density in the range of 0.05 g / cm ^{3 to} 0.5 g / cm ³ , and the pore formed in the film material has a pore diameter in the range of 1 nm to 500 μm. pore size range of the thickness 10μm~1000μm layers, the range of density of ^{0.05g / cm 3 ~0.5g / cm 3} , the porous formed film material 1nm~5 It is preferable in the range of 0 .mu.m.

  According to the present invention, since the nanofiber layer is supported by the film material having the film material arranged on one side or both sides of the nanofiber layer and supporting the nanofiber layer, the nanofiber layer is usually insufficient in strength. Compared with the fact that practical use is significantly restricted, it is possible to ensure sufficient strength in practical use, and the nanofiber is mainly composed of chitin / chitosan-based material having antibacterial properties. Since the specific surface area of the nanofiber constituting the nanofiber layer is increased and the antibacterial property is also increased, an effect that the laminate can be applied to various uses can be obtained.

  Hereinafter, an embodiment of a layered product concerning the present invention is described with reference to drawings.

  As shown in FIG. 1, the laminate 10 of the present embodiment has a nanofiber structure layer 1 as a nanofiber layer composed of nanofibers (nanofibers) 1a mainly composed of a chitin / chitosan-based material. ing.

The nanofiber structure layer 1 is formed in a sheet shape by depositing nanofibers 1a spun using an electrospinning method in layers. The nanofiber 1a has a fiber diameter of nanoscale by spinning a spinning solution in which a chitin / chitosan-based material is dissolved. In this example, the fiber diameter of the nanofiber 1a is formed to 1000 nm or less. The thickness of the nanofiber structure layer 1 is formed to be 10 μm or more in consideration of handleability and strength. The density of the nanofiber structure layer 1 is set to 0.01 g / cm ³ or more in consideration of gas and liquid passage. The nanofiber structure layer 1 is formed with micropores through which gas or liquid can pass through the fiber gap between the nanofibers 1a. The microporous hole diameter d1 is adjusted to a range of 100 to 1600 nm by adjusting the fiber diameter of the nanofiber 1a and the density of the nanofiber structure layer 1.

  A support material 2 as a film material for supporting the nanofiber structure layer 1 is disposed on both surfaces of the nanofiber structure layer 1. The nanofiber structure layer 1 and each support material 2 are bonded together by thermocompression bonding or pressure bonding by interposing a heat-welding resin or a chemical adhesive. For the support material 2, a nonwoven fabric, a woven fabric, a knitted fabric, a fiber net (mesh) formed using the fiber material 2a, or a resin film made of a synthetic resin is used. General-purpose synthetic fibers and natural fibers are used for the fiber material 2a forming the nonwoven fabric. Examples of the material of the fiber material 2a include polyester, polyethylene, polypropylene, polyamide, polyimide, polyethylene naphthalate, polyvinyl chloride, polyvinylidene chloride, acrylic, acrylic, latex, polysulfone, polytetrafluoroethylene, and polyvinylidene fluoride. Fluoropolymer, Polylactic acid, Cellulose derivatives such as cellulose acetate and hydroxypropyl cellulose, Polyvinyl alcohol, Polyurethane, Polyethylene oxide, Polycaprolactone, Cotton, Hemp, Rayon, Polynosic, Pulp, Wool, Silk, Alumina and glass, Ceramic, Carbonized Examples thereof include silicon, rock wool, carbon, and boron. A nonwoven fabric or the like is formed by a single or a combination of these. The nonwoven fabric used for the support material 2 may be a general method such as a spun bond method, a thermal bond method, a chemical bond method, a spun lace method, a needle punch method, a stitch bond method, a wet method (paper making method) or an air lay method. The manufactured nonwoven fabric can be used. As the woven fabric, the knitted fabric, and the fiber net, a general-purpose knitted fabric can be used without being limited to a knitted fabric or a knitting method.

The thickness of the support material 2 is formed to be 20 mm or less in consideration of handleability and strength. The density of the support material 2 is set to 0.6 g / cm ³ or less in consideration of the gas and liquid passage properties. The support material 2 is formed with a pore that allows passage of gas or liquid in the fiber gap between the fiber materials 2a. The porosity formed in the support material 2 is formed so that the pore diameter d2 is larger than the microporous pore diameter d1 formed in the nanofiber structure layer 1. The hole diameter d2 is adjusted to 1 nm or more by adjusting the fiber diameter of the fiber material 2a and the density of the support material 2.

  The laminated body 10 is formed by laminating nanofibers 1a spun by electrospinning on the upper surface of one support material 2 to form a nanofiber structure layer 1, and further superimposing the other support material 2 to perform thermocompression bonding. Manufactured. For the production of this laminate 10, a laminate production apparatus equipped with an electrospinning apparatus is used.

  As shown in FIG. 2, the laminate manufacturing apparatus 40 includes an electrospinning apparatus 20. On the upstream side of the electrospinning apparatus 20, a supply roller 32 for supplying a spunbonded nonwoven fabric made of polypropylene (hereinafter abbreviated as PP) fiber which is one support material 2 is disposed. A hot air dryer 35 for drying the nanofiber structure layer 1 formed on the upper surface of the support material 2 is disposed on the downstream side of the electrospinning apparatus 20. The hot air dryer 35 has a blower that blows hot air from above onto the nanofiber structure layer 1 formed on the support material 2. On the downstream side of the hot air dryer 35, a supply roller 33 for supplying a spunbonded non-woven fabric made of PP fibers which is the other support material 2 is arranged. The spunbond nonwoven fabric supplied from the supply roller 33 is laminated on the upper surface side of the dried nanofiber structure layer 1. On the downstream side of the supply roller 33, a pair of heatable pressure rollers 37 for heat-pressing the nanofiber structure layer 1 and the support material 2 disposed on both surfaces thereof are disposed. On the downstream side of the pressure roller 37, a winding roller 38 for winding the heat-pressed laminated body 10 is disposed. The pressure roller 37 and the take-up roller 38 are connected to a rotation drive motor (not shown), and the support material 2 supplied from the supply roller 32 by these rotation drive forces is applied to the nanofiber by the electrospinning device 20. The support layer 2 supplied with the structure layer 1 and supplied from the supply roller 33 is stacked and conveyed to the take-up roller 38 via the pressure roller 37.

  In the electrospinning by the electrospinning apparatus 20, it is necessary to adjust the environmental humidity during spinning, so as shown in FIG. 3A, the laminate manufacturing apparatus 40 can avoid the entry and exit of outside air as much as possible. Housed in a housing 39. The humidity condition of the production environment greatly affects the fiber diameter of the nanofiber 1a, and if the humidity is too high, spinning becomes difficult (it is difficult to form a fiber). Therefore, it is preferable to reduce the humidity by performing dehumidification or the like. On the other hand, if the humidity is too low, the tip of the spinning nozzle that sprays the spinning solution is likely to dry, and clogging is likely to occur in the spinning solution. For this reason, it is preferable to adjust environmental humidity to 20 to 60%, preferably 30 to 50%.

  In the electrospinning apparatus 20, the spinning solution is sprayed from the spinning nozzle by applying a high voltage to the spinning solution in which the chitin / chitosan-based material is dissolved, and the nanofiber structure is formed on the upper surface of the support material 2 supplied from the supply roller 32. Layer 1 is formed.

  As shown in FIG. 4A, the electrospinning apparatus 20 has a metal spinning nozzle 22 for spraying the spinning solution. The spinning nozzle 22 is supported by the casing 39 of the laminate manufacturing apparatus 40 substantially vertically so that the tip is on the lower side. The diameter of the tip of the spinning nozzle 22 is 0.05 to 5.0 mm in accordance with the fiber diameter of the nanofiber 1a. The spinning liquid is fed to the spinning nozzle 22 by a supply pump (not shown) from a spinning liquid tank (not shown) that stores the spinning liquid. A power supply V capable of generating a high voltage of 2 to 30 kV is connected to the spinning nozzle 22. A conductive substrate 24 is disposed substantially horizontally below the spinning nozzle 22. The conductive substrate 24 and the power source V are grounded. For simplicity, only one spinning nozzle 22 is shown in FIG. 4A, but a plurality of spinning nozzles 22 can be used in the laminate manufacturing apparatus 40 (FIG. 3A). )reference).

  When a high voltage of 2 to 30 kV is applied between the tip of the spinning nozzle 22 and the conductive substrate by the power source V, the spinning solution fed from the spinning solution tank (not shown) to the spinning nozzle 22 is atomized from the tip of the spinning nozzle 22. The electrospray phenomenon that is sprayed on is generated. The sprayed spinning raw material becomes fibrous due to an electric repulsive force acting between molecules. When the support material 2 supplied from the supply roller 32 passes over the conductive substrate 24, the fibrous spinning raw material is deposited in the form of a sheet on the upper surface of the support material 2, and the nanofiber structure layer 1 is formed. The thickness of the nanofiber structure layer 1 can be adjusted by the time during which the spinning solution is sprayed.

  The spinning solution is prepared by dissolving chitin / chitosan-based material as a main component in a solubilizer. In the spinning solution, a spinning aid such as a water-soluble polymer such as polyethylene glycol and polyvinyl alcohol having compatibility with the chitin / chitosan-based material is appropriately blended in accordance with the intended use. By adding a spinning aid, it is possible to stabilize the spray state during electrospinning. The amount of the spinning aid added is, for example, 0.001 to 1 part by weight (concentration 0.1 to 100%) with respect to 1 part by weight of chitosan.

  Chitin, chitosan, degradation products or derivatives thereof are used as chitin / chitosan-based materials for spinning. Chitin is a polysaccharide (polymer) having N-acetylglucosamine as a constituent monosaccharide, and has a degree of acetylation (a ratio in which the amino group of the monosaccharide is acetylated) of 90 to 100%. Chitosan is a polymer obtained by subjecting chitin to deacetylation, and has a degree of deacetylation (ratio of deacetylation of the aminoacetyl group of chitin) of 65 to 100%. Chitosan used for the spinning material is not particularly limited as long as it has acid solubility and is commercially available. If the molecular weight of chitosan is extremely low, it is easily deformed by heat and becomes brittle in strength. Conversely, if the molecular weight is high, the viscosity becomes high when preparing a spinning solution, and the solubility, spinnability (spinning property) (Ease of handling) becomes difficult to handle. For this reason, it is preferable that the molecular weight of chitosan is in the range of 10,000 to 1,000,000, preferably in the range of 30,000 to 500,000. The molecular weight of chitosan is, for example, a gel permeation method (using an Asahipack 7M-HQ column, manufactured by Showa Denko KK) using high-performance liquid chromatography using a pullulan of known molecular weight as a standard substance and a light scattering detector. It can be measured easily.

  Examples of chitin / chitosan degradation products include chitin oligosaccharides, chitosan oligosaccharides, and water-soluble chitosan (molecular weight 20,000 to 3,000). Moreover, as derivatives of chitin and chitosan, partially deacetylated chitin, hydroxypropylated chitosan, carboxymethylated chitin, carboxymethylated chitosan, sulfated chitosan, sulfated chitin prepared to a degree of deacetylation of 40 to 60% And quaternized chitosan. By using such chitin / chitosan derivatives and degradation products, various functions such as cell activation, moisturizing property, antiviral activity, antibacterial activity, etc. of chitin / chitosan materials can be improved or imparted. Can do.

  As the solubilizer used for the preparation of the spinning solution, one suitable for dissolving the spinning raw material to be used is used. For example, when chitosan is used as the raw material for spinning, it is selected from organic acids such as hydrochloric acid, acetic acid, lactic acid, ascorbic acid and malic acid, pyrrolidone carboxylic acid, glutamic acid and aspartic acid. The concentration of the spinning raw material to be dissolved in the solubilizer affects the productivity of the nanofiber 1a, the fiber structure and performance of the nanofiber 1a after spinning, and is preferably as high as possible. Considering solubility and spinnability, it is preferably 1 to 30% by weight, more preferably 5 to 25%.

  A spinning solution is charged into a spinning solution tank, and is supplied to the spinning nozzle 22 by a pressurization by air or the like or by a liquid transport pump, and a high voltage is applied by a power source V. Although one spinning nozzle 22 is possible as shown in FIG. 4 (A), in practice, if a plurality of spinning nozzles 22 are used and sprayed simultaneously as shown in FIG. The nanofiber structure layer 1 can be obtained efficiently. Moreover, the thickness and density of the nanofiber structure layer 1 can be adjusted efficiently by using a plurality of spinning nozzles 22.

  The support 2 having the nanofiber structure layer 1 formed on the upper surface is transported to a hot air dryer 35 and dried with hot air from a blower. At this time, when acetic acid is used as the solubilizing agent for chitosan, the water resistance of the nanofiber 1a can be improved by heating and removing the acetic acid remaining in the nanofiber structure layer 1. The dried nanofiber structure layer 1 is conveyed downstream, and the support material 2 supplied from the supply roller 33 is laminated on the upper surface side of the nanofiber structure layer 1.

  The nanofiber structure layer 1 on which the support material 2 is arranged on both sides is conveyed to the pressure roller 37. When passing between the pressure rollers 37, the support member 2 and the nanofiber structure layer 1 are thermocompression bonded to form a composite 10 that is combined and integrated. The laminate 10 that has been heat-pressed is wound around the winding roller 38.

  Next, for examples of the laminate 10 manufactured according to the present embodiment, and for each application of filter applications, hygiene material applications such as masks, cosmetic material applications such as face masks, and regenerative medical applications such as cell culture substrates. Examples of the manufactured laminate 10 will be described. The various sheet materials used as comparative examples are also described.

(Example 1)
As shown in Table 1 below, in Example 1, chitosan (manufactured by Kyowa Technos Co., Ltd., molecular weight of about 30,000) separated and purified from crab shells was used as a spinning raw material. A chitosan solution of 18% chitosan and 6% acetic acid (w / w) and 5% polyethylene oxide (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 500,000) are uniformly mixed at a weight ratio of 8: 2 (20 Viscosity at 200 ° C. to 400 cp). In this spinning solution, the weight ratio of chitosan and polyethylene oxide is 93.5: 6.5. A metal needle 23G (manufactured by Musashi Engineering, SUS304) was used for the spinning nozzle 22, and a voltage of 18 kV to a maximum of 30 kV was applied during spinning. In electrospinning, the nanofiber structure layer 1 having a thickness of 70 μm and a density of 0.03 g / cm ³ was formed by spraying directly onto the conductive substrate 24. The environmental conditions during spinning were set to a temperature of 20 to 30 ° C. (room temperature) and a humidity of 20 to 50%. When the surface of the obtained nanofiber structure layer 1 was observed with a scanning electron microscope (manufactured by Topcon, SM-200), a fiber structure with a fiber diameter of 100 to 300 nm was confirmed. In addition, the thickness of the obtained nanofiber structure layer 1 of chitosan is a film thickness meter (manufactured by Ozaki Mfg. Co., Ltd.) when the thickness is 0.01 to 10 mm, and scans when the thickness is 0.1 to 10 μm. It was measured with a scanning electron microscope.

(Example 2)
As shown in Table 1, in Example 2, a PP spunbond nonwoven fabric (manufactured by Nippon Nonwoven Fabric Co., Ltd., basis weight: 20 g / m ² ) was used as the support material 2. Using the laminate manufacturing apparatus 40, electrospinning was performed under the same conditions as in Example 1, and the support material 2 was thermocompression bonded to both surfaces of the nanofiber structure layer 1 having a thickness of 165 μm and a density of 0.07 g / cm ³ (140 ° C. Pressure 2 MPa). That is, the laminate 10 of Example 2 has a sandwich structure in which the nanofiber structure layer 1 is sandwiched between the support members 2 from both sides.

(Example 3)
As shown in Table 1, in Example 3, the pulp made of dry nonwoven fabric (manufactured by Lion Corporation, basis weight 78 g / m ²⁾ was used as a support 2. As illustrated in FIG. 3B, the laminate 10 was manufactured using the laminate manufacturing apparatus 40 that does not have the supply roller 33. Before the nanofiber structure layer 1 is formed on the pulp nonwoven fabric supplied from the supply roller 32 of the laminate manufacturing apparatus 40, polyvinyl alcohol (Wako Pure Chemical Industries, Ltd., polymerization degree 2000, fully saponified product) A 5% aqueous solution of (abbreviated as PVA) was spotted 1 μL at 5 mm intervals. In the same manner as in Example 2, electrospinning was performed to form a nanofiber structure layer 1 having a thickness of 165 μm and a density of 0.07 g / cm ^3. After drying with hot air at 100 ° C., a support material 2 was formed on the upper side of the nanofiber structure layer 1. The pressure was applied by the pressure roller 37 without supplying the pressure. That is, the laminated body 10 of Example 3 has the support material 2 only on one side of the nanofiber structure layer 1.

Example 4
As shown in Table 1, in Example 4, a spunbond nonwoven fabric (manufactured by Nippon Nonwoven Fabric Co., Ltd., basis weight: 20 g / m ² ) made of polyethylene (hereinafter abbreviated as PE) was used as the support material 2. Example 2 was the same as in Example 2 except that the thermocompression bonding conditions were 120 ° C. and the pressure was 1 MPa.

(Example 5)
As shown in Table 1, Example 5 was the same as Example 2 except that the nanofiber structure layer 1 having a thickness of 290 μm and a density of 0.12 g / cm ³ was formed by electrospinning. The laminated body 10 of Example 5 is manufactured for filter use.

(Example 6)
As shown in Table 1, Example 6 was the same as Example 2 except that the nanofiber structure layer 1 having a thickness of 200 μm and a density of 0.10 g / cm ³ was formed by electrospinning. The laminate 10 of Example 6 is manufactured for use in sanitary materials such as a mask.

(Example 7)
As shown in Table 1, in Example 7, PE film laminated cotton (cotton) (abbreviated as PE cotton in Table 1) was used as the support material 2, and the thickness was 100 μm by electrospinning. A nanofiber structure layer 1 having a density of 0.10 g / cm ³ was formed, and the same procedure as in Example 2 was performed except that the support material 2 was not supplied from the supply roller 33. The laminated body 10 of Example 6 is manufactured for cosmetic material applications such as a face mask.

(Example 8)
As shown in Table 1, Example 8 was the same as Example 7 except that a spunbonded nonwoven fabric made of polylactic acid (abbreviated as PLA in Table 1) was used as the support material 2. The laminate 10 of Example 6 is manufactured for regenerative medical uses such as a cell culture substrate.

(Comparative Example 1)
As shown in Table 2 below, in Comparative Example 1, a 350 μm-thick nonwoven fabric (spun lace method, basis weight: 40 g / m ² ) made of chitosan fiber having a fiber diameter of 20 μm was used.

(Comparative Example 2)
As shown in Table 2, in Comparative Example 2, a spunbonded nonwoven fabric (manufactured by Nippon Nonwoven Fabric Co., Ltd., basis weight: 12 g / m ² ) made of polyethylene terephthalate (hereinafter abbreviated as PET) was used.

(Comparative Example 3)
As shown in Table 2, in Comparative Example 3, a PE film (made by Kureha Co., Ltd., thickness 15 μm) of a wrapping material for food packaging was used.

(Comparative Example 4)
As shown in Table 2, in Comparative Example 4, two pieces of the PP spunbond nonwoven fabric used for the support material 2 in Example 2 were used, and thermocompression bonded at 140 ° C. and 2 MPa. That is, Comparative Example 4 is a sheet material having a two-layer structure.

(Comparative Example 5)
As shown in Table 2, in Comparative Example 5, the nonwoven fabric used for the support material 2 in Example 2 was used. That is, Comparative Example 5 is a PP spunbond nonwoven fabric.

(Comparative Example 6)
As shown in Table 2, in Comparative Example 6, a porous sheet made of mixed cellulose for a filtration filter (manufactured by Advantech, thickness 145 μm, pore diameter 0.45 μm) was used.

<Evaluation test>
With respect to the laminate 10 of each example and the sheet material of the comparative example, each test of the pore size, antibacterial property, air permeability (pressure loss), fine particle capturing property and tensile strength of the nanofiber structure layer 1 was performed by the following test methods. evaluated.

(Fiber diameter / hole diameter)
For measurement of the fiber diameter and microporous pore diameter (including pore diameter distribution) of the nanofiber structure layer 1, a scanning electron microscope (Topcon, SEM-200), and a bubble of ASTM F316-86 and JIS K 3832 are used. An automatic pore size distribution measuring device based on the point method (manufactured by POROUS-MATERIALS, palm porometer) was used. As shown in FIGS. 5A and 5B, the chitosan fiber of Comparative Example 1 has a fiber diameter of about 20 μm, whereas the chitosan nanofiber 1a of Example 1 has a fiber diameter of 100 to 300 nm. there were. It was confirmed that the average fiber diameter of the nanofiber structure layer 1 of each Example other than Example 1 was 1000 nm or less. From the measurement results of the fiber diameter, it was found that there is a correlation between the average fiber diameter and the fiber diameter distribution range. That is, when the average fiber diameter is 70 nm, the fiber diameter is distributed in the range of 40 to 140 nm. When the average fiber diameter is 200 nm, the fiber diameter is distributed in the range of 140 to 400 nm, and the average fiber diameter is 300 nm. In each case, it was found that the fiber diameter was distributed in the range of 200 to 450 nm. Moreover, it confirmed that the average hole diameter of the nanofiber structure layer 1 of each Example was 1000 nm or less.

(Antibacterial)
The antibacterial property was evaluated according to the shake flask method (antibacterial product technical council standard) and the bacterial liquid absorption method (JIS L 1902 “Antibacterial test method for fiber products, antibacterial method”). In the shake flask method, Staphylococcus aureus (NBRC (IFO) 12732) or E. coli (Escherichia coli, NBRC (IFO) 3972), which were sold by the National Institute for Product Evaluation Technology, were used as test bacteria. A test piece obtained by cutting the laminate 10 into 4 cm × 4 cm was sterilized with ethanol using gauze or the like, then subjected to dry heat sterilization or autoclave sterilization, and then aseptically placed in a sterilized culture flask. A culture flask is inoculated with 10 ml of a test bacterial solution (normally diluted with broth culture solution, containing 10 ⁴ to 10 ⁵ test bacteria, pH 7.0 to 7.2), and covered with aluminum foil. The culture was performed with constant amplitude in a constant temperature shake incubator at 35 ± 1 ° C. As a control test group, put only 10 ml of the same test bacterial solution, collect the bacterial solution after storage culture for 0 hours (control test group only) and 24 hours, and live bacteria by agar plate culture method using standard agar medium Number was measured. Antibacterial properties were evaluated by the difference in increase / decrease in the number of viable bacteria (test bacteria). In addition, the number of viable bacteria in the control test group at 0 hours of storage, that is, the number of bacteria inoculated on each test piece was 5.4 × 10 ⁵ .

On the other hand, in the bacterial solution absorption method, the same test bacteria as in the shake flask method were used. A test piece of laminate 10 (treated in the same manner as the shake flask method) was aseptically placed in a sterile vial. Pipet exactly 0.2 ml of the test bacterial solution (10 ⁵ to 10 ⁶ cells / ml), inoculate several places on the test piece, close the vial lid, and store at 37 ° C. for 18 to 24 hours (stationary) Culture). After storage, add 20 ml of physiological saline for washing (8.5 g NaCl, 2.0 g nonionic surfactant twin 80 dissolved in distilled water to a total volume of 1000 ml), close the lid, and shake The test bacteria were washed out from each test piece. The washed solution was collected and the viable cell count was measured by an agar plate culture method using a nutrient agar medium. Antibacterial properties were evaluated by the difference in increase / decrease in the number of viable bacteria (test bacteria). The viable cell count was obtained by multiplying the bacterial concentration (cells / ml) by the amount of physiological saline for washing (20 ml).

(Breathable)
The air permeability of the line filter holder when a test piece of the cut laminate 10 is set on a line filter holder (manufactured by Advantech, SUS, caliber 25 mm) and a certain amount of gas such as nitrogen or air is allowed to flow. The pressure difference between the inlet side and the outlet side was evaluated by measuring with a fine differential pressure gauge (Okano Seisakusho).

(Fine particle capture)
In the fine particle capturing property, 11 types of powder 1 for JIS test 1 were set while setting the test piece of the laminated body 10 cut into a filter holder for vacuum filtration (manufactured by Advantech, glass, caliber 47 mm) and applying vibration to the holder. 1 g of standard particles (obtained from Japan Powder Industrial Technology Association, containing 65 ± 5% of particles with a particle size of 1 μm or more) using a pump (manufactured by Iwaki, maximum flow rate 15 liters / min) with a flow rate of 5 liters / Min for 5 minutes. The particle capturing ability was evaluated by measuring the weight of the particles remaining on the test piece. That is, the percentage of the particle weight remaining on the test piece with respect to the particle weight used in the test was calculated as the fine particle capture rate (%).

(Tensile strength)
The tensile strength was measured using a tensile strength test apparatus (Instron, Model 3342). For the measurement, a test piece obtained by cutting the laminate 10 into a width of 2 mm was used, and the load (N / mm ² ) at the time of breaking the test piece was measured with a gauge distance of 50 mm and a crosshead speed of 4 mm / min.

Hereinafter, evaluation results of pore diameter, antibacterial property, air permeability (pressure loss test), fine particle capturing property and tensile strength will be described. The measurement results of antibacterial properties, ventilation resistance, fine particle capture rate and tensile strength are summarized in Table 3 below. In Table 3, the number of viable bacteria after the test is shown as an antibacterial result, and the number of inoculated bacteria (5.4 × 10 ⁵ ) is omitted. The ventilation resistance indicates a differential pressure when nitrogen gas of 1 liter per minute is flown per 1 cm ² of the test piece (1 L / min / cm ² ).

  In the nanofiber structure layer 1 of the laminate 10 of each example, it was confirmed that the ion exchange rate (ion exchange capacity) per 1 g was 5.4 meq (milli equivalent). From this, it can be expected that the adsorptivity of fine particles containing microorganisms and the like is excellent. Moreover, it was confirmed that the microporous pore diameter of the nanofiber structure layer 1 is distributed in the range of 100 to 1600 nm, and the average pore diameter was 500 nm. From this, it was found that the nanofiber structure layer 1 was excellent in air permeability. Furthermore, as a result of observation by a scanning electron microscope, in comparison with the nanofiber structure layer 1 of Example 1, in the laminate 10 of Examples 2 to 8 in which the support material 2 was bonded, the nanofiber structure layer 1 No change in shape was observed, and it was confirmed that the nanofiber structure layer 1 and the support material 2 were bonded. As shown in FIG. 6, on the surface of the laminate 10, the surface of the nanofiber structure layer 1 can be observed from the voids (porous support material) of the fiber material 2 a constituting the support material 2. It can be seen that dense micropores are formed on the surface of 1. Further, as shown in FIG. 7, in the inclined cross section of the laminate 10, the fiber material 2 a of the support material 2 is softened and deformed between the nanofiber structure layer 1 and the support material 2 that are heat-pressed, and It can be seen that the support 2 is securely bonded (portion indicated by an arrow).

  The antibacterial evaluation results are described by comparing Comparative Example 1 of a nonwoven fabric formed with conventional chitosan fibers, Comparative Example 2 of a nonwoven fabric made of PET, and Example 1 of a nanofiber structure layer 1 formed with nanofibers 1a of chitosan. To do. As shown in Table 4 below, in Comparative Example 1, the number of bacteria after the test was decreased with respect to the number of inoculated bacteria, and an obvious antibacterial property was exhibited. This is probably because chitosan was a basic (cationic) polymer and thus exhibited antibacterial activity against various microorganisms including Escherichia coli and Staphylococcus aureus used as test bacteria. Moreover, in Comparative Example 2, the number of bacteria after the test was almost the same as the number of inoculated bacteria, and it was revealed that they did not have antibacterial properties. On the other hand, in Example 1, the number of viable bacteria was not recognized after the test and showed remarkable antibacterial properties. This is based on chitosan, which has been known to have antibacterial properties, and since the specific surface area of the nanofiber 1a with a nanoscale fiber diameter is increased, the contact with microorganisms is improved and the antibacterial properties are improved. It is thought that. From this, it is considered that the antibacterial property is improved by using the nanofiber 1a due to the so-called nanosize effect. In other words, it is difficult to expect improvement in antibacterial properties even if the fiber layer is composed of fibers having a fiber diameter exceeding 1000 nm.

  Moreover, about the evaluation result of air permeability, the comparative example 4 of PP nonwoven fabric of a two-layer structure, the comparative example 6 of the cellulose sheet used for filtration filters, the nanofiber structure layer of chitosan between two layers of PP nonwoven fabric A description will be given by comparing Example 2 with 1 interposed therebetween. As shown in FIG. 8, in Comparative Example 4, since the density is small and the porosity is large, almost no differential pressure is recognized. On the other hand, in Comparative Example 6, the differential pressure increases as the flow rate of nitrogen gas increases, and shows a tendency to increase even when the pressure exceeds 30 kPa. On the other hand, in the laminated body 10 of Example 2, a slight differential pressure is recognized, but is suppressed to 10 kPa or less.

  Further, when comparing the fine particle capture rate, as shown in FIG. 9, in Comparative Example 4, the fine particle capture rate was 38.9%, whereas in Example 2 and Comparative Example 6, the fine particle capture rate was 100% and 99.4%, indicating that almost all the fine particles used in the test were captured. Considering both the air permeability and the fine particle capturing ability, Comparative Example 4 is excellent in the air permeability, but the fine particle capturing ability cannot provide a sufficient effect. This is considered to be due to the large porosity, and it is apparent that it cannot be used as a separating material such as a filter material. On the other hand, in Comparative Example 6, although the fine particle capturing property is excellent, the air permeability is remarkably lowered with an increase in the flow rate. Therefore, even if it can be used as a separating material for temporary filtration or the like, the use period becomes long. Can not be used in some cases. On the other hand, in the laminated body 10 of Example 2, since it is excellent in fine particle capture | acquisition property, since pressure loss can also be restrained small, it can be used as a high performance filter material even if it is used over a long period of time. There was found.

In addition, as for tensile strength, Comparative Example 3 of PE film for food packaging, Comparative Example 4 of PP nonwoven fabric having a two-layer structure, Comparative Example 5 of PP nonwoven fabric, Example 1 of nanofiber structure layer 1 of chitosan, chitosan Example 2 in which PP nonwoven fabric is thermocompression bonded to both surfaces of the nanofiber structure layer 1 will be described in comparison. As shown in FIG. 10, Comparative Example 3, Comparative Example 5, a weighted at break showed ^{0.3997N / mm 2, 0.4236N / mm} 2 , respectively. Moreover, in the comparative example 4, 1.0530 N / mm < ² > was shown and the tensile strength improved from the comparative example 5 of 1 layer structure. This indicates that high strength is obtained with synthetic resin fibers and films, and the tensile strength is improved by laminating two layers. On the other hand, in Example 1, but shows the two measurement results, respectively 0.2414N ^/ mm 2, showed 0.1289N / mm ^2. From this, it was found that only the nanofiber structure layer 1 cannot obtain sufficient tensile strength even if it is formed in a sheet shape because the fiber diameter is nanoscale. On the other hand, in the laminate 10 of Example 2, the tensile strength was greatly improved to 2.1080 N / mm ² . From this, it was found that the tensile strength is remarkably improved by laminating a PP nonwoven fabric on both surfaces of the nanofiber structure layer 1 to form a laminate 10 having a three-layer structure.

  Next, the laminates 10 of Examples 5 to 8 manufactured for the filter, the mask, the face mask, and the cell culture substrate will be described in order.

As shown in Table 3, in the laminate 10 of Example 5 in which the nanofiber structure layer 1 having a thickness of 290 μm and a density of 0.12 g / cm ³ was formed by electrospinning, and PP nonwoven fabric was bonded to both sides, In addition to excellent properties, air permeability, particle trapping properties, and tensile strength were superior to those of the comparative examples. Moreover, in this laminated body 10, the porosity is 92.4%, the through-hole diameter (refer code | symbol d1 of FIG. 1) is distributed in the range of 209-1639 nm, the average is 495 nm, and a specific surface area is 25.92 m < ² > / g. It was confirmed that. Since the specific surface area is large, it can be expected to improve the function of chitosan that adsorbs harmful substances, pigments and the like that affect the human body such as endotoxin and pyrogen. Considering comprehensively from these evaluation results, in addition to being excellent in fine particle capturing properties and being able to suppress pressure loss to a small level, it can improve the antibacterial properties and adsorbability that are functions of chitosan. It has been found that it is extremely effective for high performance filter material applications for the purpose of removing (separating) harmful substances in liquids. When the laminated body 10 is applied to such a filter material application, the nanofiber structure layer 1 is set to a thickness of 10 to 1000 μm and a density of 0.05 to 0.5 g / cm ³ and supported. It has been confirmed that the material 2 preferably has a pore diameter in the range of 1 nm to 500 μm.

Moreover, as shown in Table 3, in the laminate 10 of Example 6 in which the nanofiber structure layer 1 having a thickness of 200 μm and a density of 0.10 g / cm ³ was formed by electrospinning, and a PP nonwoven fabric was bonded to both surfaces, In addition to antibacterial properties, air permeability, particle trapping properties and tensile strength were superior to those of the comparative examples. In addition, it was confirmed that this laminate 10 had a large specific surface area and excellent flexibility. From this, when touching the human body etc. directly, it can be firmly attached because of its flexibility, and it also has excellent breathability to suppress stuffiness and rash and reduce irritation to the skin I can expect. Furthermore, the nanofiber structure layer 1 can be expected to quickly absorb sweat and waste products by capillary action (specific surface area effect). Considering comprehensively from these evaluation results, it is possible to ensure breathability, flexibility, and removal of harmful substances, so it is extremely effective for use in sanitary materials such as masks. found. When the laminate 10 is applied to such hygiene material applications, the nanofiber structure layer 1 is set to a thickness of 10 to 1000 μm and a density of 0.05 to 0.5 g / cm ³ and supported. It has been confirmed that the material 2 preferably has a pore diameter in the range of 1 nm to 500 μm.

Further, as shown in Table 3, the nanofiber structure layer 1 having a thickness of 100 μm and a density of 0.10 g / cm ³ was formed by electrospinning, and the lamination of Example 7 in which laminated cotton of PE film was bonded to one side. In the body 10, not only antibacterial properties but also air permeability, particle trapping properties, and tensile strength were superior to those of the comparative examples. In addition, it was confirmed that this laminate 10 was excellent in flexibility, lightweight, and excellent in moisture retention and liquid retention. From this, it can be expected that the nanofiber structure layer 1 side of chitosan can be firmly adhered to a human body or the like, and the irritation to the skin can be reduced. Moreover, since it is excellent in moisturizing property and liquid retaining property, it is possible to retain a moisturizing ingredient and emulsion for cosmetics. Therefore, it is possible to suppress moisture transpiration from the skin and to apply the emulsion directly to the skin. Furthermore, since laminated cotton of PE film is stuck on one side, the emulsion or the like retained in the nanofiber structure layer 1 is prevented from exuding and evaporating, so that the emulsion or the like is surely applied to the skin. Can do. From these evaluation results, it was proved that it was extremely effective for cosmetic material applications such as a face mask because it was excellent in flexibility and also excellent in moisture retention and liquid retention. When applying the laminate 10 in such a cosmetic material applications, the range of thickness 10~1000μm nanofibres structure layer 1, and sets the range of the density of 0.01 to 0.5 g / cm ^3, the support It has been confirmed that the thickness of the resin film material used for the material 2 is preferably in the range of 100 to 2000 μm. In the cosmetic material application, instead of the resin film, it is also possible to use a non-woven fabric or the like in which pores are formed as the support material 2.

In addition, as shown in Table 3, the nanofiber structure layer 1 having a thickness of 100 μm and a density of 0.10 g / cm ³ was formed by electrospinning, and a polylactic acid (PLA) spunbond nonwoven fabric was bonded to one side. In the laminated body 10 of 8, the antibacterial property, air permeability, particle trapping property, and tensile strength were all superior to those of the comparative examples. In addition, cell engraftment when used as a culture substrate for animal cells such as human and mouse-derived fibroblasts (each cell is seeded on a sample piece of laminate 10 and cultured in an atmosphere at 37 ° C.). It was confirmed that the property was improved and the proliferation property was excellent. This is because the chitosan nanofiber structure layer 1 is formed of nanoscale fibers, so that the cell recognizability can be improved. Moreover, since it is excellent in air permeability, the through-hole is formed and it is thought that it is excellent also in the liquid permeability of a culture solution. From these evaluation results, it was proved that it was effective as a culture substrate when culturing cells, tissues, etc. in vitro, and as a material for regenerative medical use that returns newly constructed tissues, etc. to the living body. It can be expected to be promising. When applying a laminate 10 in culture substrate such regenerative medicine applications, the range of thickness 10~1000μm nanofibres structure layer 1, the range of density of 0.01 to 0.5 g / cm ³ It has been confirmed that it is preferable to set the support material 2 in the range of 1 μm to 10 mm in thickness.

  As specifically described above for each example, in the laminate 10 of the present embodiment, the support material 2 is attached to one or both surfaces of the nanofiber structure layer 1 formed of the nanofibers 1a of the chitin / chitosan-based material. Are combined. For this reason, even if the tensile strength of the nanofiber structure layer 1 is insufficient, since the nanofiber structure layer 1 is supported by the support material 2, a practically sufficient strength can be obtained. In addition, since the nanofiber structure layer 1 is formed of a chitin / chitosan-based material having a nanoscale fiber diameter, the function of the chitin / chitosan-based material, particularly antibacterial properties, can be improved by the nanosize effect. Among the functions of various chitin / chitosan-based materials, the results of evaluating the dye adsorption property, protein adsorption property, and nucleic acid adsorption property together with the above-described antibacterial property, air permeability, particle capturing property, and tensile strength are shown in Table 5 below. Shown together.

  In Table 5, relative evaluation with respect to the sheet material of the comparative example 1 of each function is shown about the laminated body 10 of Example 1, Example 2, and Example 4, and the sheet material of the comparative example 4 and the comparative example 6. . That is, it is superior to Comparative Example 1; ◯ mark, equivalent to Comparative Example 1; Δ mark, inferior to Comparative Example 1; From Table 5, it can be seen that each example has an improved function of chitosan.

  The laminate 10 of this embodiment having such performance can be applied to various uses. For example, the environmental field represented by a high-performance filter for air cleaning (see Example 5), the sanitary field represented by a high-functional mask (see Example 6), and the face mask for beauty (see Example 7). It can be used as a material in the field of regenerative medicine represented by the cosmetics field and cell culture substrate (see Example 8). Furthermore, considering the functions of chitin / chitosan-based materials, for example, wound-healing dressings in the medical field, medical gauze, surgical dresses, materials for artificial dialysis membranes, etc. Endotoxin etc.) It can be expected as a material that can be used for removal filter materials, freshness-keeping sheets and packaging materials in the food field, and the like.

  In the present embodiment, an example in which chitosan is used as the material of the nanofiber 1a mainly composed of chitin / chitosan-based material is shown, but the present invention is not limited to this, and a degradation product of chitin and chitosan. Or a derivative may be used. In the present embodiment, the electrospinning method is exemplified as a method for spinning the nanofiber 1a. However, the present invention is not limited to this, and a method capable of spinning a fiber having a nanoscale fiber diameter. Any method may be used as long as it exists. Furthermore, in this embodiment, although the method of forming the nanofiber structure layer 1 horizontally when electrospinning was illustrated, this invention is not limited to this. For example, as shown in FIG. 4B, if the conductive substrate 24 of the electrospinning apparatus 20 is disposed vertically, the nanofiber structure layer 1 can be formed vertically.

  Moreover, in this embodiment, although the example which manufactures the laminated body 10 continuously using the laminated body manufacturing apparatus 40 was shown, this invention is not limited to this, The support cut | judged to desired size The nanofiber structure layer 1 may be formed on the material 2, and the support material 2 may be laminated on the nanofiber structure layer 1.

  Furthermore, in this embodiment, although the example which makes the microporous hole diameter d1 of the nanofiber structure layer 1 the range of 100-1600 nm was shown, this invention is not limited to this, For example, bacteria, mold, For the purpose of capturing fine particles such as dust, the pore diameter d1 is preferably 500 nm or less, more preferably 250 nm or less. The pore diameter d1 is adjusted by selecting the molecular weight and concentration of the chitin / chitosan-based material used for the spinning solution preparation, the type of spinning aid added to the spinning solution, the spinning conditions such as temperature, humidity, and spinning time. can do. In the present embodiment, an example in which the thickness of the nanofiber structure layer 1 is 10 μm or more is shown, but the present invention is not limited to this. What is necessary is just to adjust the thickness of the nanofiber structure layer 1 arbitrarily according to the performance and intensity | strength of the laminated body 10, and a use. The larger the thickness is, the smaller the average value of the pore diameter d1 is, and it becomes easier to capture fine particles. On the other hand, the smaller the thickness is, the lower the performance may be. A thickness of 0.1 μm is necessary, and the thickness is preferably 1 μm or more.

  Furthermore, in the present embodiment, an example in which the nanofiber structure layer 1 is formed by electrospinning a chitin / chitosan-based material is shown, but the present invention is not limited to this. For example, in order to improve the strength and performance of the nanofiber structure layer 1, the synthetic polymer material may be simultaneously electrospun or melt spun. Examples of such a synthetic polymer material include cellulose acetate, polylactic acid, polycaprolactone, polyethylene, polypropylene, and polyester. The solvent for electrospinning the synthetic polymer material may be selected according to the material, and examples thereof include acetone, N, N-dimethylformamide, methanol, and glacial acetic acid. In electrospinning, the acid of the dissolving agent used in the spinning solution may remain, but the acid can be removed by heating during drying. If removal of the acid by heating is insufficient, neutralization and washing may be performed.

  Furthermore, in the present embodiment, the nanofiber structure layer 1 obtained by electrospinning chitosan has been exemplified. However, for example, chitosan may be cross-linked with a cross-linking agent in order to improve strength depending on the use of the laminate 10. May be. If it does in this way, since it can suppress that the nanofiber 1a swells especially in water etc., the performance at the time of using the laminated body 10 in water etc. can be ensured. Crosslinking can be performed by mixing a crosslinking agent having two or more functional groups with chitosan and reacting the functional group of the crosslinking agent with the amino group of chitosan. Examples of such a crosslinking agent include glutaraldehyde, carbodiimide, carbonylimidazole, diepoxy compound, dicarboxylic acid anhydride, epichlorohydrin, and the like. The degree of crosslinking in the case of crosslinking can be set in the range of 0.01 to 100%, but if the degree of crosslinking is too high, the flexibility and antibacterial properties of the nanofiber structure layer 1 are reduced. The crosslinking degree is preferably set in the range of 0.1 to 30%. In the case of cross-linking, it is preferable to sufficiently wash so that the cross-linking agent does not remain, for example, with various buffers such as purified water, physiological saline, phosphate buffer, ethanol, acetone, or the like.

  In the present embodiment, an example in which the nanofiber structure layer 1 and the support material 2 are bonded together by thermocompression bonding has been shown, but the present invention is not limited to this. For example, they may be bonded together with a chemical adhesive, and may be selected depending on the material of the support material 2 or the use of the laminate 10, for example, by combining either or both of thermocompression bonding and chemical bonding. Furthermore, in this embodiment, although the example which bonds the support material 2 to both surfaces of the nanofiber structure layer 1 was shown, depending on a use, it is also possible to bond the support material 2 only to one side (refer Example 3). ).

  As exemplified in the present embodiment, when a material having heat melting property such as polyethylene or polypropylene is used for the support material 2, the nanofiber structure layer 1 and the support material 2 are directly laminated and bonded together. be able to. When a non-heat-meltable material such as cotton or pulp is used for the support material 2, heating is performed with a heat-meltable adhesive resin interposed between the nanofiber structure layer 1 and the support material 2. As a method of interposing the adhesive resin, a method of coating a suspension of the adhesive resin (powder) by a dot method or a scatter method, or a spider web between the nanofiber structure layer 1 and the support material 2 Examples thereof include a method of heat-bonding after being sandwiched between layers, a method of mixing a spinning resin with a bonding resin when spinning the nanofiber structure layer 1, and performing heat-bonding as it is.

  Usable adhesive resins include polyester, polyethylene, polypropylene, polyamide, polylactic acid, ethylene vinyl acetate copolymer, xylene resin, epoxy resin, phenol resin, urethane resin, vinyl ester resin, unsaturated polyester resin, polyimide, Melamine resin, maleic acid resin, polyolefin emulsion, polycaprolactone, nitrocellulose, cellulose acetate, hydroxypropylcellulose, ethylcellulose, methylcellulose, polyvinyl ether, polyvinyl acetate, polyvinyl alcohol, polyethylene oxide, carboxyvinyl polymer, pullulan, starch, starch Derivatives, chitosan salts, chitosan derivatives, water-soluble chitin derivatives, hyaluronate, chondroitin sulfate, pectin salts, pectin Conductor, alginates, alginic acid derivatives include glue, gelatin, rubber or the like.

  In addition, if an adhesive resin that softens above 200 ° C. is used when thermocompression bonding is performed, the chitin / chitosan-based material may be altered by heating and the function may be impaired. It is preferable to set the temperature so that the function of the material does not deteriorate. Among adhesive resins, polyethylene (softening point 100 ° C, melting point 125 ° C), polypropylene (softening point 140 ° C, melting point 165 ° C), nylon (softening point 180 ° C, melting point 215 ° C), ethylene vinyl acetate polymer (Softening point 50 to 60 ° C.), polyolefin emulsion (85 to 90 ° C.) and the like are melted (softened) without exceeding 200 ° C., so that the chitin / chitosan material can be prevented from being deteriorated.

  Furthermore, as shown in the present embodiment, when the pressure is applied by the pressure roller 37 or the like when the heat pressing is performed, the nanofiber structure layer 1 and the support material 2 can be hardly separated from each other. Can be formed substantially uniformly. Of course, when the laminated body 10 is formed after the support material 2 is cut into a desired size in advance, a normal hot press machine or the like may be used. Moreover, the laminated body 10 can also be formed in a bulky structure by thermally melting the adhesive resin in a hot air atmosphere of 50 to 200 ° C.

  When the nanofiber structure layer 1 and the support material 2 are bonded together with a chemical adhesive, the chemical adhesive is applied to the nanofiber structure layer 1 and adhered to the support material 2 by a chemical reaction or the like. As a method of applying the chemical adhesive, there is a method of spraying a very small amount of chemical adhesive from the nozzle so as not to peel off the nanofiber structure layer 1 or the support material 2. For example, when the support material 2 is bonded to one side of the nanofiber structure layer 1, as shown in FIG. 11, a spray nozzle is provided on the upstream side (supply roller 32 side) of the electrospinning apparatus 20 of the laminate manufacturing apparatus 40. It is also possible to spray continuously by arranging the spray device 34 (see also FIG. 3B). Further, when the support material 2 is bonded to both surfaces of the nanofiber structure layer 1, as shown in FIG. 3A, spray devices 34 are arranged on the upstream side of the spinning nozzle 22 and the downstream side of the hot air dryer 35, respectively. To do. After spraying, the chemical adhesive is cured by quickly overlapping and pressing with a pressure roller 37 or a press. At the time of curing, for example, a hot air dryer or a hot press machine may be used, which is effective when a material that cannot be thermally welded such as a pulp nonwoven fabric or cotton gauze is used for the support material 2. Further, if the nanofiber structure layer 1 of chitosan is formed after spraying a dilute acidic aqueous solution with the spraying device 34, the chitosan is softened by the acidic aqueous solution that has permeated the support material 2, so that the nanofibers 1a are bonded to each other. By doing so, delamination of the nanofiber structure layer 1 can be prevented.

  Usable chemical adhesives include water-soluble adhesives such as polyvinyl acetate, polyvinyl alcohol, carboxyvinyl polymer, pullulan and starch paste, polyvinyl ether, xylene resin that is thermosetting resin, epoxy resin, phenol resin, and urethane. Examples thereof include resins, vinyl ester resins, unsaturated polyester resins, polyimides, melanin resins, and maleic acid resins.

  INDUSTRIAL APPLICABILITY The present invention can improve the function of chitin / chitosan-based materials and provide a laminate having practically sufficient strength. Therefore, the present invention contributes to the manufacture and sale of laminates that can be used in various applications. With the above applicability.

It is sectional drawing which shows the laminated body of embodiment which concerns on this invention. It is sectional drawing which shows typically the laminated body manufacturing apparatus for manufacturing the laminated body of embodiment. It is a perspective view which shows a laminated body manufacturing apparatus typically, (A) shows the manufacturing apparatus of the double-sided laminated body which affixes a support material on both surfaces of a nanofiber structure layer, (B) shows on one side of a nanofiber structure layer The manufacturing apparatus of the single area layer body which bonds a support material together is shown. It is sectional drawing which shows typically the outline | summary of the electrospinning apparatus which produces the nanofiber structure layer of embodiment, (A) shows the horizontal formation apparatus which forms a nanofiber structure layer horizontally, (B) is nanofiber 1 shows a vertical forming apparatus for forming a structural layer vertically. It is an electron micrograph, (A) shows the surface of the nanofiber structure layer of Example 1, (B) shows the surface of the nonwoven fabric of Comparative Example 1, respectively. 3 is an electron micrograph showing the surface of the laminate of Example 2. FIG. 3 is an electron micrograph showing an inclined cross section of a laminate of Example 2. FIG. It is a graph which shows the comparison of the pressure difference with respect to passage of nitrogen gas about the laminated body of an Example, and the sheet material of a comparative example. It is a graph which shows the measurement result of particle capture nature about the layered product of an example, and the sheet material of a comparative example. It is a graph which shows the measurement result of tensile strength about the layered product of an example, and the sheet material of a comparative example. It is sectional drawing which shows typically manufacture of a laminated body when the spraying apparatus which sprays a liquid is arrange | positioned to the laminated body manufacturing apparatus of embodiment.

Explanation of symbols

1 Nanofiber structure layer (nanofiber layer)
2 Support material (film material)
2a Nanofiber (nanofiber)
DESCRIPTION OF SYMBOLS 10 Laminated body 20 Electrospinning apparatus 40 Laminated body manufacturing apparatus

Claims (16)

  It has a nanofiber layer composed of chitin / chitosan-based material as a main component and nanofibers having a nanometer fiber diameter, and a film material disposed on one or both sides of the nanofiber layer and supporting the nanofiber layer. A laminate characterized by the following.   2. The film material according to claim 1, wherein the film material is formed with a porous material that allows a gas or a liquid to pass therethrough, and the porous material has a larger pore diameter than a microporous material formed by nanofibers of the nanofiber layer. Laminated body. The laminate according to claim 1, wherein the nanofiber layer has a density of 0.01 g / cm ³ or more.   The laminate according to claim 1, wherein the nanofiber layer has a thickness of 10 μm or more.   The laminate according to claim 1, wherein the nanofiber has a fiber diameter of 1000 nm or less.   The laminate according to claim 5, wherein the nanofiber layer has a greater antibacterial property than a fiber layer composed of fibers having a fiber diameter of more than 1000 nm.   The laminate according to claim 1, wherein the film material is a nonwoven fabric, a woven fabric, a knitted fabric, a fiber net, or a resin film.   The laminate according to claim 7, wherein the film material has a thickness of 20 mm or less.   The laminated body according to claim 2, wherein the pore formed in the film material has a pore diameter of 1 nm or more.   The laminate according to claim 7, wherein the film material is made of a single material or a combination of materials selected from polyester, polyethylene, polypropylene, polylactic acid, cotton, rayon, pulp, and derivatives thereof.   2. The laminate according to claim 1, wherein the chitin / chitosan-based material is chitin, chitosan, chitin or a degradation product of chitosan, and one or a combination selected from chitin or chitosan derivatives. .   The nanofiber layer and the film material are bonded with one or more adhesive components selected from polyester, polyethylene, polypropylene, polylactic acid, polyvinyl acetate, polyvinyl alcohol, epoxy resin, phenol resin, and starch. The laminate according to claim 1, which is characterized. The nanofiber layer has thickness in the range of 10 .mu.m to 1000 .mu.m, density in the range of ^{0.01g / cm 3 ~0.5g / cm 3} , and the resin in the range wherein the film material has a thickness of 100μm~2000μm It is a film, The laminated body of Claim 1 characterized by the above-mentioned. The nanofiber layer has thickness in the range of 10 .mu.m to 1000 .mu.m, density in the range of ^{0.01g / cm 3 ~0.5g / cm 3} , and the film material thickness in the range of 1μm~10mm The laminate according to claim 1. The nanofiber layer has a thickness in the range of 10 μm to 1000 μm, a density in the range of 0.05 g / cm ^{3 to} 0.5 g / cm ³ , and the pore formed in the film material has a pore diameter of 1 nm to 500 μm. The laminate according to claim 2, wherein the laminate is within the range. The nanofiber layer has a thickness in the range of 10 μm to 1000 μm, a density in the range of 0.05 g / cm ^{3 to} 0.5 g / cm ³ , and the pore formed in the film material has a pore diameter of 1 nm to 500 μm. The laminate according to claim 2, wherein the laminate is within the range.

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