JP2022164368A - Antibacterial fiber material and production method thereof - Google Patents

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 The present invention relates to an antimicrobial textile material and a method for manufacturing the same. More particularly, it relates to an antibacterial fiber material having high oil absorption and a method for producing the same.

Textile materials are used in various fields such as clothing, electronics, automobiles, medicine, and building materials. In particular, a product using a fiber material with a small fiber diameter has characteristics such as a large surface area, a high porosity, a small pore size, high air permeability, and a high fluid permeation rate.

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 field of filters such as water tank purification (see, for example, Patent Document 1). ).

JP 2016-17527 A

By the way, antibacterial properties are sometimes required for products such as oil absorbing materials used around water, such as kitchen sinks in general households and oil-water separation tanks in restaurants, from a sanitary point of view. The material is expected to be used in the product concerned.

Since the oil absorbing material is used for the purpose of preventing oil from flowing into the sewage system, high oil absorption is required.
Therefore, there is a demand for the development of antibacterial fiber materials with high oil absorbency.

As a result of intensive studies by the present inventors, it was 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 denser gaps between the fibers. As a result, the capillary force is improved, and as a result, it was found that high oil absorption can be expressed, and the present invention was completed. That is, the gist of the present invention is as follows.

[1] An antibacterial fiber material containing fibers obtained by mixing fibers A having an average fiber diameter of 5 to 50 μm and fibers B having an average fiber diameter of 0.3 to 2 μm, and an antibacterial agent. .
[2] The antibacterial fiber material according to [1], wherein the fungus is at least one of bacteria and fungi.
[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 metal ions thereof.
[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 with respect to 100% by mass of the fiber.
[6] The antibacterial fiber material according to any one of [1] to [5], which is cotton-like, sheet-like, or nonwoven fabric-like.
[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], which has an oil absorbency of 20 or more.
[9] The method for producing an antibacterial fiber material according to any one of [1] to [8], comprising a thermoplastic resin having a melt flow rate (temperature of 230°C, load of 2.16 kg) of 200 g/10 min or more A method for producing an antibacterial fiber material, comprising a step of spinning a mixture of antibacterial agents by a meltblowing method.
[10] The method for producing an antibacterial fiber material according to [9], wherein the thermoplastic resin is an olefinic thermoplastic resin.

The antibacterial fiber material of the present invention exhibits high oil absorption while having antibacterial properties.

1 is an electron micrograph of the fiber material produced in Reference Example 1. FIG.

An example of a preferred mode for carrying out the present invention will be described below. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments.

[Antibacterial fiber material]
The antibacterial fiber material of the present invention contains fibers in which fibers A having an average fiber diameter of 5 to 50 μm and fibers B having an average fiber diameter of 0.3 to 2 μm are mixed, and an antibacterial agent. do.
Fibers in which fibers A having an average fiber diameter of 5 to 50 μm and fibers B having an average fiber diameter of 0.3 to 2 μm are mixed have denser gaps between the fibers. Therefore, the capillary force is improved, resulting in high oil absorption. As used herein, the term "mixed" refers to a state in which fibers are intricately entangled as shown in FIG.
In addition, since the antibacterial fiber material contains an antibacterial agent, it has antibacterial properties.

The fibers A and B are the same fibers, but are distinguished by the average fiber diameter.
The average fiber diameter is measured as follows. A scanning electron microscope (SEM) is used to measure the image of the fiber. 10 thick or thin fibers are selected from one image in which about 30 to 150 fibers can be observed, and the diameter of each fiber is measured. Each fiber diameter is measured for three images, and the average fiber diameter is calculated from a total of 30 fiber diameters. The average fiber diameter of the thick fibers corresponds to the average fiber diameter of the A fibers, and the average fiber diameter of the thin fibers corresponds to the average fiber diameter of the B fibers.
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.

Fiber A is a fiber having an average fiber diameter of 5-50 μm. The average fiber diameter of the fibers A is more preferably 8-20 μm. If the average fiber diameter of the fibers A is less than 5 μm, the stiffness of the fibers will be reduced, and the oil will flow out due to its own weight when it absorbs oil, resulting in a reduced oil absorption. If the average fiber diameter of the fibers A exceeds 50 μm, even if the fibers B are present, the gaps between the fibers become sparse, the capillary force is poor, and the oil absorbency is poor.

Fiber B is a fiber having an average fiber diameter of 0.3-2 μm. The average fiber diameter of the fibers B is more preferably 0.5 to 1.5 μm. If the average fiber diameter of the fibers B is less than 0.3 μm, even if the fibers A are present, the gaps between the fibers are sparse, the capillary force is poor, and the oil absorbency is poor. If the average fiber diameter of the fibers B is more than 2 μm, the gaps between the fibers are similarly sparse, the capillary force is poor, and the oil absorption is reduced.

A method for producing a fiber containing fiber A and fiber B will be described later.

Bacteria targeted by the antibacterial fiber material are preferably at least one of bacteria and fungi. Bacteria include, for example, Enterobacter, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella, Enterococcus, Campylobacter, Helicobacter synedi, Helicobacter pylori, Vibrio cholerae, Vibrio parahaemolyticus, Bacillus anthracis, Treponema, Examples include Clostridium botulinum and Klebsiella pneumoniae. Examples of molds include black mold, blue mold, aspergillus, black mold, black mold, black yeast, red mold, and trichophyton.

As the antibacterial agent, either an inorganic antibacterial agent or an organic antibacterial agent may be used, or both of them may be used, 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 the metal elements. ions. Among these, at least one selected from the group consisting of silver, copper, zinc and metal ions thereof is preferred.

The average particle size of the inorganic antibacterial agent is preferably 0.1 to 5 μm from the viewpoint of preventing fiber breakage, falling off of the inorganic antibacterial agent, and occurrence of shots (resin lumps) during fiber production. 4 to 1 μm is more preferred.
The average particle size of the inorganic antibacterial agent is the value of the volume average median size measured with a laser diffraction particle size analyzer manufactured by Shimadzu Corporation.

The inorganic antibacterial agent may have the above-mentioned metals or metal ions supported on a carrier. Examples of supports include silicates (zeolite, calcium silicate, magnesium metasilicate, etc.), silica gel, glass, phosphates (calcium phosphate, zirconium phosphate, etc.), metal oxides (titanium oxide, zinc oxide, etc.), titanium acid salts (potassium titanates), ceramics, and the like.

Examples of organic antibacterial agents include 1,2-benzisothiazolin-3-one, N-flurodichloromethylthiophthalimide, 2,3,5,6-tetrachloroisophthalonitrile, 2-(4-thiazolyl)benzo imidazole, benzimidazole methyl carbamate, 10,10′-oxybisphenoxane acyl, 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine, 2-pyridinethiol-1-oxide zinc, N, N-dimethyl-N'-(fluorodichloromethylthio)-N'-phenylsulfamide, thiazoline compounds such as 2-octyl-4-isothiazolin-3-one, alkyldimethylbenzylammonium salts (where the number of carbon atoms in the alkyl group is 8 to 18) and other quaternary ammonium salts.

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 properties may be poor. If the content of the antibacterial agent exceeds 20% by mass, shots (resin lumps) may occur in the fibers during the production of the antibacterial fiber material, resulting in poor oil absorbency.

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, and non-woven fabric.

Since the antibacterial fiber material exhibits high oil absorption, it can be suitably used as an oil-absorbing article. Among them, the antibacterial fiber material exhibits antibacterial properties, and thus can be suitably used as products used around water such as kitchen sinks in general households and oil-water separation tanks in restaurants.

The antibacterial fiber material preferably has an oil absorption value of 20 or more, more preferably 25 or more, calculated by the following formula.
Oil absorption = [(Weight of antibacterial fiber material after oil absorption) - (Initial weight of antibacterial fiber material)] / (Initial weight of antibacterial fiber material)
Here, the oil absorption is performed by immersing the cotton-like antibacterial fiber material in salad oil for 5 minutes.

[Method for producing antibacterial fiber material]
The method for producing an antibacterial fiber material of the present invention is the above method for producing an antibacterial fiber material, and is a mixture of a thermoplastic resin and an antibacterial agent having a melt flow rate (temperature of 230°C, load of 2.16 kg) of 200 g/10 min or more. is spun by the meltblowing method.
A fiber A having an average fiber diameter of 5 to 50 μm by spinning a mixture of a thermoplastic resin and an antibacterial agent having a melt flow rate (temperature of 230 ° C., load of 2.16 kg) of 200 g / 10 min or more by a melt blow method, A fiber comprising fine fibers B having an average fiber diameter of 0.3 to 2 μm is obtained. If the melt flow rate of the thermoplastic resin (temperature 230° C., load 2.16 kg) is less than 200 g/10 min, the average fiber diameter of the fibers becomes excessively large. As a result, the fiber material has less oil absorption and is inferior in oil absorption.

The conditions for the melt blowing method include, for example, the following conditions. A nozzle die having 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 added at a rate of 0.1 to 5 g/min per nozzle hole. to dispense. Conditions for applying air having a temperature of room temperature to 400° C. to the extruded fibers can be mentioned.

The thermoplastic resin may have a melt flow rate (temperature of 230° C., load of 2.16 kg) of 200 g/10 min or more, and examples thereof include polyester, polyamide, polyolefin, and polyurethane (PU). Polyesters include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polylactic acid (PLA), and the like. Polyamides include nylon 6 (N6), nylon 66 (N66), nylon 11 (N11) and the like. Polyolefins include polyethylene (PE), polypropylene (PP), polystyrene (PS) and the like.
The thermoplastic resin is preferably polyolefin, which is an olefinic thermoplastic resin.

The melt flow rate of the thermoplastic resin (temperature 230° C., load 2.16 kg) is 200 g/10 min or more, preferably 500 g/10 min or more, more preferably 1000 g/10 min or more. Moreover, the upper limit of the melt flow rate (temperature of 230° C., load of 2.16 kg) of the thermoplastic resin is preferably 2000 g/10 min or less. The value of the melt flow rate of the thermoplastic resin (temperature 230°C, load 2.16 kg) is one of the factors that affect the average fiber diameter of the fibers (fibers A and B) obtained by spinning by the meltblowing method. is.
Here, the melt flow rate (temperature 230° C., load 2.16 kg) is a value measured according to ASTM D1238.

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 a meltblowing method. The antibacterial agent is preferably an inorganic antibacterial agent because it is exposed to high temperatures in melt blowing, and includes silver, copper, zinc, mercury, tin, lead, gold, platinum, cobalt, nickel, aluminum, zirconium, molybdenum, bismuth, chromium, At least one selected from the group consisting of metal elements such as thallium and metal ions thereof is more preferred.

The amount of the antibacterial agent in the mixture is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on 100% by mass of the thermoplastic resin. If the amount of the antibacterial agent is less than 0.1% by mass, the antibacterial properties may be poor. If the amount of the antibacterial agent is more than 20% by mass, shots (polymer lumps) may occur, and the resulting antibacterial fiber material may have low oil absorption and poor oil absorption.
The amount of the antibacterial agent is one of the factors that affect the average fiber diameter of the fibers (fibers A and B) obtained by spinning by the meltblowing method.

The antibacterial agent may be further added to the antibacterial fiber material obtained by spinning by the meltblowing method. When added to the antimicrobial fiber material, an organic antimicrobial agent can be used because the antimicrobial agent is not exposed to high temperatures. In addition, when further added to the antibacterial fiber material, it is thought that the average fiber diameter of the fibers (fiber A and fiber B) will not be affected, so the amount of addition should be adjusted so that the desired antibacterial properties can be exhibited. It has the advantage of being easy.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The methods for measuring various physical properties are the methods described above unless otherwise specified. In addition, the "fiber material" in the measurement method section indicates both antibacterial fiber material and fiber material.

[Average fiber diameter of fiber A]: The fiber surface was observed at an arbitrary point of the fiber material with a scanning electron microscope (SEM) under the conditions of an acceleration voltage of 15.0 kV and a magnification of 300 times. Ten thick fibers on the image were selected and the fiber diameter was measured. Three images were measured, and a total of 30 fiber diameters were measured, and the average fiber diameter of the fibers A was calculated.

[Average fiber diameter of fiber B]: The fiber surface was observed at an arbitrary point of the fiber material with a scanning electron microscope (SEM) under the conditions of an acceleration voltage of 15.0 kV and a magnification of 1500 times. Ten thin fibers on the image were selected and the fiber diameter was measured. Three images were measured, and a total of 30 fiber diameters were measured, and the average fiber diameter of the fibers B was calculated.

[Oil absorption (g)]: After immersing 3.0 g of cotton-like fiber material (3.5 g of oil adsorbent in Comparative Example 1) in salad oil for 5 minutes, it was removed from the salad oil and placed on a wire mesh for 5 minutes. left undisturbed. After that, the weight of the antibacterial textile material or oil sorbent after absorbing the oil was measured. Then, the oil absorption was calculated by the following formula.
Oil absorption (g) = (Weight of fiber material or oil adsorbent after oil absorption) - (Initial weight of fiber material or oil adsorbent)

[Oil absorption]: Calculated by the following formula from the oil absorption and the initial weight of the fiber material or oil adsorbent.
Oil absorption = oil absorption (g) ÷ (initial weight of fiber material)

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

(Reference example 2)
A flocculate was prepared in the same manner as in Reference Example 1 except that a polypropylene resin (density: 0.9 cm/cm ³ ) having a melt flow rate (temperature of 230°C, load of 2.16 kg) of 1500 to 2000 g/10 min was used. of fibrous materials were produced. Table 1 shows the average fiber diameter of the fibers A, the average fiber diameter of the fibers B, the oil absorption, and the oil absorption of the manufactured fiber material.

(Reference example 3)
A cotton-like fiber material was prepared in the same manner as in Reference Example 1 except that a polypropylene resin (density: 0.9 cm/cm ³ ) having a melt flow rate (temperature of 230°C, load of 2.16 kg) of 100 g/10 min was used. manufactured. Table 1 shows the average fiber diameter of the fibers A', the average fiber diameter of the fibers B', the oil absorption and the oil absorption of the manufactured fiber material.

From Table 1, when a fiber material is produced using polypropylene with a melt flow rate (temperature of 230° C., load of 2.16 kg) of 200 g/10 min or more, fiber A with an average fiber diameter of 5 to 50 and fiber A with an average fiber diameter of 0.50 are produced. It can be seen that a fiber material in which 3 to 2 fibers B are mixed can be produced. Further, from FIG. 1, in the fiber material in which the fibers A having an average fiber diameter of 8.5 μm and the fibers B having an average fiber diameter of 0.6 μm are mixed, the gaps between the fibers are dense. Therefore, as shown in Table 1, the fiber material had high oil absorption and oil absorption, and exhibited high oil absorption (Reference Examples 1 and 2).
On the other hand, when a fiber material is produced using polypropylene having a melt flow rate (temperature of 230° C., load of 2.16 kg) of less than 200 g/10 min, fibers A′ with an average fiber diameter of 93.2 μm and fibers with an average fiber diameter of 2.0 μm are produced. It was a fiber material in which 2 μm fibers B′ were mixed. The value of oil absorption and oil absorption of the fiber material was low, and the oil absorption was poor (Reference Example 3).

(Example 1)
A cotton-like antibacterial fiber material was prepared in the same manner as in Reference Example 1, except that a mixture of polypropylene resin (density: 0.9 cm/cm ³ ) and silver-based antibacterial agent (median diameter: 0.48 μm) was used as the raw material. manufactured. Table 2 shows the average fiber diameter of fiber A, the average fiber diameter of fiber B, the oil absorption and the oil absorption of the manufactured antibacterial fiber material.
The amount of the silver-based antibacterial agent was 0.5% by mass with respect to 100% by mass of the fiber.

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

(Comparative example)
Oil absorption and oil absorption were measured using a commercially available oil adsorbent (trade name “Sutorindesu”, manufactured by Eiwa Sangyo). Table 2 shows the measurement results.

From Table 2, regardless of the amount of the silver-based antibacterial agent, an antibacterial fiber material was produced in which fibers A with an average fiber diameter of 5 to 50 μm and fibers B with an average fiber diameter of 0.3 to 2 μm were mixed. The produced antibacterial fiber materials had higher oil absorption and oil absorption values than commercially available oil adsorbents, and exhibited high oil absorption (Examples 1 to 3).

Antibacterial Test 1 was conducted using the fiber material produced in Reference Example 1 and the antibacterial fiber materials produced in Examples 1-3. Antibacterial test 1 was performed as follows.
0.5 g of cotton-like textile material or antibacterial textile material was weighed out. Enterobacter, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa were added to 49.5 mL of a mixed bacterial solution, and after stirring for 24 hours at 30°C, the number of bacteria was measured. The results are shown in Table 3 below.

From Table 3, it can be confirmed that the antibacterial fiber material containing the antibacterial agent has antibacterial properties.

Using the antibacterial fiber material produced in Example 3, an antibacterial test was conducted in accordance with JIS L 1902:2015 (bacterial liquid absorption method). Test conditions are shown below.
Test strain: Staphylococcus aureus NBRC 12732
Viable cell count measurement method: Pour plate culture method The test bacterial solution uses a test bacterial solution to which 0.05% of a surfactant (Tween 80) has been added. Proliferation value ≥ 1.0)

The activity value according to JIS L 1902:2015 (bacterial liquid absorption method) of the antibacterial fiber material produced in Example 3 was 5.9. According to JIS L 1902:2015, an activity value of 2.0 or more is defined as "having an antibacterial effect", so the antibacterial fiber material produced in Example 3 is recognized to have an antibacterial effect.

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

The activity value according to JIS L 1921:2015 (absorption method) of the antibacterial fiber material produced in Example 3 was 3.4 for black mold and 2.5 for blue mold. According to JIS L 1921:2015, an activity value of 2.0 or more is defined as having an antifungal effect.

Claims (10)

A fiber A having an average fiber diameter of 5 to 50 μm;
A fiber obtained by mixing a fiber B having an average fiber diameter of 0.3 to 2 μm,
An antibacterial fiber material containing an antibacterial agent. 2. The antibacterial fiber material according to claim 1, wherein the fungus is at least one of bacteria and fungi. The antibacterial fiber material according to claim 1 or 2, wherein the antibacterial agent is an inorganic antibacterial agent. The antibacterial fiber material according to claim 3, wherein the inorganic antibacterial agent contains at least one selected from the group consisting of silver, copper, zinc, and metal ions thereof. The antibacterial fiber material according to any one of claims 1 to 4, wherein the content of the antibacterial agent is 0.1 to 20% by mass with respect to 100% by mass of the fiber. The antibacterial fiber material according to any one of claims 1 to 5, which is cotton-like, sheet-like or non-woven fabric-like. The antibacterial fiber material according to any one of claims 1 to 6, which is an oil-absorbing article. 8. The antibacterial fiber material according to claim 7, which has an oil absorption of 20 or more. A method for producing the antibacterial fiber material according to any one of claims 1 to 8,
A method for producing an antibacterial fiber material, comprising a step of spinning a mixture of a thermoplastic resin having a melt flow rate (temperature of 230°C, load of 2.16 kg) of 200 g/10 min or more and an antibacterial agent by a meltblowing method. 10. The method for producing an antibacterial fiber material according to claim 9, wherein the thermoplastic resin is an olefinic thermoplastic resin.

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