Antibacterial fiber material and method for producing the same

Abstract

To provide an antibacterial fiber material having antibacterial properties and high oil absorption properties.SOLUTION: An antibacterial fiber material is used that contains a fiber mixture of a fiber A having an average fiber diameter of 5 to 50 μm and a fiber B having an average fiber diameter of 0.3 to 2 μm, and an antibacterial agent.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an antibacterial fiber material and a method for producing the same. More specifically, the present invention relates to an antibacterial fiber material having high oil absorbency and a method for producing the same.

Background Art

[0002] Fiber materials are used in various fields such as clothing, electricity, automobiles, medicine, and building materials. In particular, products using fiber materials with a small fiber diameter have characteristics such as a large surface area, a high space ratio, a small pore diameter, high air permeability, and a high fluid permeation rate.

[0003] In consideration of such characteristics, it has been proposed to use a nanofiber member having an antibacterial function in which an antibacterial agent is mixed in a fiber member in the filter field such as water tank purification (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, products such as oil-absorbing materials used in the water area such as a kitchen sink in a general household or an oil-water separation tank in a restaurant may also require antibacterial properties from a hygienic point of view, and a fiber material having an antibacterial function is expected to be used for such products.

[0006] Since the oil-absorbing material is used for the purpose of preventing oil from flowing into the sewer, high oil absorbency is required. Therefore, there is a demand for the development of an antibacterial fiber material having high oil absorbency.

Means for Solving the Problems

[0007] As a result of intensive studies, the inventors of the present invention have found that fibers in which fiber A having an average fiber diameter of 5 to 50 μm and fiber B having an average fiber diameter of 0.3 to 2 μm are mixed have closer gaps between the fibers, resulting in improved capillary force, and as a result, can exhibit high oil absorbency, and have thus completed the present invention. That is, the gist of the present invention is as follows.

[0008] [1] An antibacterial fiber material containing a fiber in which fiber A having an average fiber diameter of 5 to 50 μm and fiber B having an average fiber diameter of 0.3 to 2 μm are mixed, and an antibacterial agent. [2] The antibacterial fiber material according to [1], wherein the fungus is at least one of bacteria and mold. [3] The antibacterial fiber material according to [1] or [2], wherein the antibacterial agent is an inorganic antibacterial agent. [4] The antibacterial fiber material according to [3], wherein the inorganic antibacterial agent contains at least one selected from the group consisting of silver, copper, zinc, and their metal ions. [5] The antibacterial fiber material according to any one of [1] to [4], wherein the content of the antibacterial agent is 0.1 to 20% by mass based on 100% by mass of the fiber. [6] The antibacterial fiber material according to any one of [1] to [5], which is in the form of cotton, sheet, or non-woven fabric. [7] The antibacterial fiber material according to any one of [1] to [6], which is an oil-absorbing article. [8] The antibacterial fiber material according to [7], having an oil absorption degree of 20 or more. [9] A method for producing an antibacterial fiber material according to any one of [1] to [8], comprising a step of spinning a mixture of a thermoplastic resin having a melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of 200 g / 10 min or more and an antibacterial agent by the melt blowing method.

[10] The method for producing an antibacterial fiber material according to [9], wherein the thermoplastic resin is an olefin-based thermoplastic resin. [Effects of the Invention]

[0009] The antibacterial fiber material of the present invention exhibits high oil absorbency while having antibacterial properties.

Brief Description of the Drawings

[0010]

Figure 1

Modes for Carrying Out the Invention

[0011] Hereinafter, an example of a preferred embodiment for carrying out the present invention will be described. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments at all.

[0012] [Antibacterial Fiber Material] The antibacterial fiber material of the present invention contains a fiber A having an average fiber diameter of 5 to 50 μm, a fiber B having an average fiber diameter of 0.3 to 2 μm, a fiber in which the fibers are mixed, and an antibacterial agent. In the fiber in which the fiber A having an average fiber diameter of 5 to 50 μm and the fiber B having an average fiber diameter of 0.3 to 2 μm are mixed, the gaps between the fibers become denser. Therefore, the capillary force is improved, and as a result, high oil absorbency is exhibited. In the present specification, "mixed" means a state in which the fibers are intricately intertwined as shown in FIG. 1. In addition, since the antibacterial fiber material contains an antibacterial agent, it has antibacterial properties.

[0013] The fiber A and the fiber B are the same fiber, but are fibers distinguished by the average fiber diameter. The average fiber diameter is measured as follows. An image of the fiber is measured using a scanning electron microscope (SEM). From one image in which about 30 to 150 fibers can be observed, 10 thick or thin fibers are selected and the fiber diameter of each is measured. The measurement of each fiber diameter is performed for three images, and the average fiber diameter is calculated from a total of 30 fiber diameters. The average fiber diameter of the thick fiber corresponds to the average fiber diameter of the fiber A, and the average fiber diameter of the thin fiber corresponds to the average fiber diameter of the fiber B. Note that the magnification of the image for measuring the fiber diameter of the thick fiber is 300 times, and the magnification of the image for measuring the fiber diameter of the thin fiber is 1500 times.

[0014] Fiber A is a fiber having an average fiber diameter of 5 to 50 μm. The average fiber diameter of fiber A is more preferably 8 to 20 μm. If the average fiber diameter of fiber A is less than 5 μm, the firmness of the fiber decreases, and when it absorbs oil, the oil flows out under its own weight, resulting in a decrease in the oil absorption amount. If the average fiber diameter of fiber A exceeds 50 μm, even if fiber B is present, the gaps between the fibers become sparse, the capillary force is inferior, and the oil absorbency is poor.

[0015] Fiber B is a fiber having an average fiber diameter of 0.3 to 2 μm. The average fiber diameter of fiber B is more preferably 0.5 to 1.5 μm. If the average fiber diameter of fiber B is less than 0.3 μm, even if fiber A is present, the gaps between the fibers become sparse, the capillary force is inferior, and the oil absorbency is poor. If the average fiber diameter of fiber B exceeds 2 μm, similarly, the gaps between the fibers become sparse, the capillary force is inferior, and the oil absorption amount decreases.

[0016] A method for manufacturing the fiber containing fiber A and fiber B will be described later.

[0017] The bacteria targeted by the antibacterial fiber material are preferably at least one of bacteria and molds. Examples of bacteria include Enterobacter spp., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella spp., Enterococcus spp., Campylobacter, Helicobacter cinaedi, Helicobacter pylori, Vibrio cholerae, Bacillus anthracis, Treponema spp., Clostridium botulinum, and Klebsiella pneumoniae. Examples of molds include Aspergillus niger, Aspergillus versicolor, Aspergillus oryzae, Aspergillus fumigatus, Penicillium chrysogenum, Exophiala dermatitidis, Candida albicans, and Trichophyton rubrum.

[0018] As the antibacterial agent, either an inorganic antibacterial agent or an organic antibacterial agent may be used, or they may be used in combination, but it is preferable to use at least an inorganic antibacterial agent. Examples of inorganic antibacterial agents include metal elements such as silver, copper, zinc, mercury, tin, lead, gold, platinum, cobalt, nickel, aluminum, zirconium, molybdenum, bismuth, chromium, and thallium, and ions of these metal elements. Among these, at least one selected from the group consisting of silver, copper, zinc, and their metal ions is preferred.

[0019] From the viewpoint of preventing yarn breakage during fiber production, shedding of the inorganic antibacterial agent, and generation of shots (resin lumps), the average particle diameter of the inorganic antibacterial agent is preferably 0.1 to 5 μm, more preferably 0.4 to 1 μm. The average particle diameter of the inorganic antibacterial agent is the value of the volume average median diameter measured by a laser diffraction particle size analyzer manufactured by Shimadzu Corporation.

[0020] The inorganic antibacterial agent may carry the above metal or metal ion on a carrier. Examples of the carrier include silicates (such as zeolite, calcium silicate, magnesium metasilicate, etc.), silica gel, glass, phosphates (such as calcium phosphate, zirconium phosphate, etc.), metal oxides (such as titanium oxide, zinc oxide, etc.), titanates (such as potassium titanate salt), and ceramics.

[0021] Examples of organic antibacterial agents include thiazoline-based compounds such as 1,2-benzisothiazolin-3-one, N-fluorodichloromethylthiophthalimide, 2,3,5,6-tetrachloroisophthalonitrile, 2-(4-thiazolyl)benzimidazole, methyl benzimidazolecarbamate, 10,10'-oxybis(phenoxyanilide), 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine, zinc 2-pyridinethiol-1-oxide, N,N-dimethyl-N'-(fluorodichloromethylthio)-N'-phenylsulfamide, 2-octyl-4-isothiazolin-3-one, and quaternary ammonium salts such as alkyldimethylbenzylammonium salts (where the alkyl group has 8 to 18 carbon atoms).

[0022] The content of the antibacterial agent is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on 100% by mass of the fiber. If the content of the antibacterial agent is less than 0.1% by mass, the antibacterial property may be inferior. If the content of the antibacterial agent exceeds 20% by mass, shots (resin lumps) may occur in the fiber during the production of the antibacterial fiber material, resulting in inferior oil absorbency.

[0023] The shape of the antibacterial fiber material is not particularly limited and can be appropriately designed according to the product. Examples of the shape of the antibacterial fiber material include cotton-like, sheet-like, or non-woven fabric-like.

[0024] Since the antibacterial fiber material exhibits high oil absorbency, it can be suitably used as an oil-absorbing article. Among them, since the antibacterial fiber material exhibits antibacterial properties, it can be suitably used as a product used in areas around water such as kitchen sinks in ordinary households and oil-water separation tanks in restaurants.

[0025] The oil absorbency value calculated by the following formula of the antibacterial fiber material is preferably 20 or more, more preferably 25 or more. Oil absorbency = [(weight of the antibacterial fiber material after oil absorption) - (weight of the initial antibacterial fiber material)] ÷ (weight of the initial antibacterial fiber material) Here, the oil absorption is carried out by immersing the cotton-like antibacterial fiber material in salad oil for 5 minutes.

[0026] [Method for producing antibacterial fiber material] The method for producing the antibacterial fiber material of the present invention is the above-described method for producing the antibacterial fiber material, and includes a step of spinning a mixture of a thermoplastic resin having a melt flow rate (temperature 230 ° C, load 2.16 kg) of 200 g / 10 min or more and an antibacterial agent by the melt blow method. By spinning a mixture of a thermoplastic resin with a melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of 200 g / 10 min or more and an antibacterial agent by the melt blowing method, fibers are obtained that include fiber A having an average fiber diameter of 5 to 50 μm and fine fiber B having an average fiber diameter of 0.3 to 2 μm. If the melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of the thermoplastic resin is less than 200 g / 10 min, the average fiber diameter of the fibers becomes excessively thick. As a result, the fiber material has a reduced oil absorption amount and is inferior in oil absorbency.

[0027] As conditions for the melt blowing method, for example, the following conditions can be cited. A nozzle die with a nozzle hole diameter of 0.1 to 2.0 mm and a pitch of 1 to 10 mm is heated to a temperature of 180 to 400 °C, and fibers are discharged at a rate of 0.1 to 5 g / min per nozzle hole. Conditions include applying air with a temperature ranging from room temperature to 400 °C to the discharged fibers.

[0028] The thermoplastic resin only needs to have a melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of 200 g / 10 min or more. Examples include polyester, polyamide, polyolefin, polyurethane (PU), etc. Examples of polyester include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid (PLA), etc. Examples of polyamide include nylon 6 (N6), nylon 66 (N66), nylon 11 (N11), etc. Examples of polyolefin include polyethylene (PE), polypropylene (PP), polystyrene (PS), etc. The thermoplastic resin is preferably polyolefin, which is an olefin-based thermoplastic resin.

[0029] The melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of the thermoplastic resin is 200 g / 10 min or more, preferably 500 g / 10 min or more, and more preferably 1000 g / 10 min or more. Also, the upper limit of the melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of the thermoplastic resin is preferably 2000 g / 10 min or less. The value of the melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of the thermoplastic resin is one of the factors that affect the value of the average fiber diameter of the fibers (Fiber A and Fiber B) obtained by melt blowing. Here, the melt flow rate (at a temperature of 230°C and a load of 2.16 kg) is a value measured in accordance with ASTM D1238.

[0030] The method for producing the antibacterial fiber material of the present invention includes a step of spinning a mixture of a thermoplastic resin and an antibacterial agent by the melt blowing method. Since the antibacterial agent is exposed to high temperatures during melt blowing, an inorganic antibacterial agent is preferred, and at least one selected from the group consisting of metal elements such as silver, copper, zinc, mercury, tin, lead, gold, platinum, cobalt, nickel, aluminum, zirconium, molybdenum, bismuth, chromium, thallium, and metal ions thereof is more preferred.

[0031] The compounding amount of the antibacterial agent in the mixture is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass, based on 100% by mass of the thermoplastic resin. If the compounding amount of the antibacterial agent is less than 0.1% by mass, the antibacterial property may be inferior. If the compounding amount of the antibacterial agent exceeds 20% by mass, shots (lumps of polymer) may occur, resulting in a decrease in the oil absorption amount of the obtained antibacterial fiber material and inferior oil absorption properties. The compounding amount of the antibacterial agent is one of the factors that affect the value of the average fiber diameter of the fibers (Fiber A and Fiber B) obtained by melt blowing.

[0032] The antibacterial agent may be further added to the antibacterial fiber material obtained by melt blowing. When further adding to the antibacterial fiber material, since the antibacterial agent is not exposed to high temperatures, organic antibacterial agents can be used. Also, when further adding to the antibacterial fiber material, it is considered that it does not affect the average fiber diameter of the fibers (Fiber A and Fiber B), so there is an advantage that the addition amount can be easily adjusted so as to exhibit the desired antibacterial property.

Examples

[0033] Next, examples will be given to explain the present invention in more detail. However, the present invention is not limited to these examples. In addition, unless otherwise specified, the measurement methods of various physical property values are based on the methods described above. Also, the "fiber material" in the part of the measurement method refers to both the antibacterial fiber material and the fiber material.

[0034] [Average fiber diameter of Fiber A]: Using a scanning electron microscope (SEM), the surface of the fiber was observed at an acceleration voltage of 15.0 kV and a magnification of 300 times for an arbitrary location of the fiber material. Ten thick fibers on the image were selected and the fiber diameter was measured. The measurement was performed for three images, and a total of 30 fiber diameters were measured to calculate the average fiber diameter of Fiber A.

[0035] [Average fiber diameter of Fiber B]: Using a scanning electron microscope (SEM), the surface of the fiber was observed at an acceleration voltage of 15.0 kV and a magnification of 1500 times for an arbitrary location of the fiber material. Ten thin fibers on the image were selected and the fiber diameter was measured. The measurement was performed for three images, and a total of 30 fiber diameters were measured to calculate the average fiber diameter of Fiber B.

[0036] [Oil absorption amount (g)]: 3.0 g of cotton-like fiber material (however, in Comparative Example 1, 3.5 g of oil adsorbent) was immersed in salad oil for 5 minutes, then taken out from the salad oil and left standing on a wire mesh for 5 minutes. Then, the weight of the antibacterial fiber material or oil adsorbent after oil absorption was measured. And the oil absorption amount was calculated by the following formula. Oil absorption amount (g) = (weight of the fiber material or oil adsorbent after oil absorption) - (initial weight of the fiber material or oil adsorbent)

[0037] [Oil absorption degree]: It was calculated from the oil absorption amount and the weight of the initial fiber material or oil adsorbent according to the following formula. Oil absorption degree = Oil absorption amount (g) ÷ (Weight of the initial fiber material)

[0038] (Reference Example 1) A polypropylene resin with a melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of 1000 - 1500 g / 10 min (density: 0.9 cm / cm 3 ) was melted at a temperature of 180 - 400 °C and extruded from a nozzle, and a cotton-like fiber material was produced by the melt blowing method in which high-temperature air at 300 - 400 °C was blown to form fibers. The average fiber diameter of fiber A, the average fiber diameter of fiber B, the oil absorption amount, and the oil absorption degree of the produced fiber material are shown in Table 1. Also, an electron micrograph of the fiber material produced in Reference Example 1 is shown in Figure 1.

[0039] (Reference Example 2) A cotton-like fiber material was produced in the same manner as in Reference Example 1, except that a polypropylene resin with a melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of 1500 - 2000 g / 10 min (density: 0.9 cm / cm 3 ) was used. The average fiber diameter of fiber A, the average fiber diameter of fiber B, the oil absorption amount, and the oil absorption degree of the produced fiber material are shown in Table 1.

[0040] (Reference Example 3) A cotton-like fiber material was produced in the same manner as in Reference Example 1, except that a polypropylene resin with a melt flow rate (at a temperature of 230 °C and a load of 2.16 kg) of 100 g / 10 min (density: 0.9 cm / cm 3 ) was used. The average fiber diameter of fiber A', the average fiber diameter of fiber B', the oil absorption amount, and the oil absorption degree of the produced fiber material are shown in Table 1.

[0041]

Table 1

[0042] From Table 1, it can be seen that when a fiber material is produced using polypropylene with a melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of 200 g / 10 min or more, a fiber material in which fiber A with an average fiber diameter of 5 to 50 and fiber B with an average fiber diameter of 0.3 to 2 are mixed can be produced. Also, from Figure 1, in the fiber material in which fiber A with an average fiber diameter of 8.5 μm and fiber B with an average fiber diameter of 0.6 μm are mixed, the gaps between the fibers are dense. Therefore, as shown in Table 1, the oil absorption amount and oil absorption degree values of the fiber material are high, and high oil absorption performance is exhibited (Reference Examples 1 and 2). On the other hand, when a fiber material is produced using polypropylene with a melt flow rate (at a temperature of 230°C and a load of 2.16 kg) of less than 200 g / 10 min, it is a fiber material in which fiber A' with an average fiber diameter of 93.2 μm and fiber B' with an average fiber diameter of 2.2 μm are mixed. The oil absorption amount and oil absorption degree values of the fiber material are low, and it is inferior in oil absorption performance (Reference Example 3).

[0043] (Example 1) A cotton-like antibacterial fiber material was produced in the same manner as in Reference Example 1, except that a mixture of a polypropylene resin (density: 0.9 cm / cm 3 ) and a silver-based antibacterial agent (median diameter: 0.48 μm) was used as the raw material. The average fiber diameter of fiber A, the average fiber diameter of fiber B, the oil absorption amount, and the oil absorption degree of the produced antibacterial fiber material are shown in Table 2. Note that the blending amount of the silver-based antibacterial agent was 0.5% by mass based on 100% by mass of the fiber.

[0044] (Examples 2 to 3) A cotton-like antibacterial fiber material was produced in the same manner as in Example 1, except that the blending amount of the silver-based antibacterial agent was changed to the amount shown in Table 2. The average fiber diameter of fiber A, the average fiber diameter of fiber B, the oil absorption amount, and the oil absorption degree of the produced antibacterial fiber material are shown in Table 2.

[0045] (Comparative Example) Using a commercially available oil adsorbent (product name "Sukitorun Desu", manufactured by Ewa Sangyo Co., Ltd.), the oil absorption amount and oil absorption degree were measured. The measurement results are shown in Table 2.

[0046]

Table 2

[0047] From Table 2, an antibacterial fiber material in which fiber A with an average fiber diameter of 5 to 50 μm and fiber B with an average fiber diameter of 0.3 to 2 μm were mixed could be produced regardless of the blending amount of the silver-based antibacterial agent. The produced antibacterial fiber material exhibited high oil absorption capacity and oil absorption degree values compared to commercially available oil adsorbents (Examples 1 to 3).

[0048] Antibacterial test 1 was conducted using the fiber material produced in Reference Example 1 and the antibacterial fiber materials produced in Examples 1 to 3. Antibacterial test 1 was conducted as follows. 0.5 g of the cotton-like fiber material or antibacterial fiber material was weighed. It was placed in 49.5 mL of a bacterial solution mixed with four types of bacteria, namely Enterobacter spp., Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, and the number of bacteria was measured after stirring at 30 °C for 24 hours. The results are shown in Table 3 below.

[0049]

Table 3

[0050] From Table 3, it was confirmed that the antibacterial fiber material containing the antibacterial agent has antibacterial properties.

[0051] Using the antibacterial fiber material produced in Example 3, an antibacterial test was conducted in accordance with JIS L 1902:2015 (bacterial solution absorption method). The test conditions are shown below. Test bacterial species: Staphylococcus aureus NBRC 12732 Method for measuring viable cell count: pour plate culture method The test bacterial solution used was a test bacterial solution added with 0.05% surfactant (Tween80) Growth value of standard cotton cloth: 2.9 (the test establishment condition is that the growth value ≧ 1.0)

[0052] The activity value of the antibacterial fiber material produced in Example 3, which conforms to JIS L 1902:2015 (bacterial liquid absorption method), was 5.9. In JIS L 1902:2015, since an activity value of 2.0 or more is defined as "having an antibacterial effect", the antibacterial fiber material produced in Example 3 shows an antibacterial effect.

[0053] Using the antibacterial fiber material produced in Example 3, a mold resistance test was conducted in accordance with JIS L 1921:2015 (absorption method). The test conditions are shown below. Test mold species: Cladosporium sphaerospermum NBRC 6348 Penicillium citrinum NBRC 6352 Test spore suspension concentration: Cladosporium sphaerospermum = 2.2×10 5 cells / ml Penicillium citrinum = 2.2×10 5 cells / ml Growth value of standard cotton cloth: Cladosporium sphaerospermum = 2.2 (the test establishment condition is that the growth value ≧ 1.5) Penicillium citrinum = 2.6 (the test establishment condition is that the growth value ≧ 1.5)

[0054] The activity values of the antibacterial fiber material produced in Example 3, which conform to JIS L 1921:2015 (absorption method), were 3.4 for Cladosporium sphaerospermum and 2.5 for Penicillium citrinum. In JIS L 1921:2015, since an activity value of 2.0 or more is defined as "having a mold resistance effect", the antibacterial fiber material produced in Example 3 shows a mold resistance effect.

Claims

1. Fiber A having an average fiber diameter of 5 to 50 μm, and fiber B having an average fiber diameter of 0.3 to 2 μm, being fibers in which they are mixed, and an inorganic antibacterial agent, an oil-absorbing article having an oil absorption of 20 or more, which is an antibacterial fiber material.

2. The antibacterial fiber material according to claim 1, wherein the fungus is at least one of bacteria and mold.

3. The antibacterial fiber material according to claim 1, wherein the inorganic antibacterial agent contains at least one selected from the group consisting of silver, copper, zinc, and their metal ions.

4. The antibacterial fiber material according to any one of claims 1 to 3, wherein the content of the antibacterial agent is 0.1 to 20% by mass with respect to 100% by mass of the fiber.

5. The antibacterial fiber material according to any one of claims 1 to 4, which is in a cotton-like, sheet-like, or non-woven fabric form.

6. A method for producing the antibacterial fiber material according to any one of claims 1 to 5, comprising a step of spinning a mixture of a thermoplastic resin having a melt flow rate (temperature 230 ° C, load 2.16 kg) of 200 g / 10 min or more and an antibacterial agent by a melt blowing method, a method for producing an antibacterial fiber material.

7. The method for producing an antibacterial fiber material according to claim 6, wherein the thermoplastic resin is an olefin-based thermoplastic resin.

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