Antiviral nonwoven fabric and protective clothing made using the same

Abstract

We provide nonwoven fabrics and protective clothing that offer excellent waterproofing and breathability, as well as superior immediate antiviral effects. [Solution] The nonwoven fabric of the present invention is a nonwoven fabric containing cerium oxide nanoparticles and a resin composition, wherein the nonwoven fabric has a first surface and a second surface, the distribution rate of cerium elements on at least the first surface of the nonwoven fabric is 10% or more, and the content of the cerium oxide nanoparticles relative to the entire nonwoven fabric is 1.0 to 2.5 g / m² 2 The resin composition consists of a thermosetting resin containing at least nitrogen atoms, and has a water pressure resistance of 800 mmH2O or more.

Description

[Technical Field]

[0001] This invention relates to an antiviral nonwoven fabric and protective clothing made using the same. [Background technology]

[0002] Since the global spread of COVID-19, antiviral products that can reduce the infectivity of viruses have attracted attention. In medical institutions that accept and treat patients infected with the virus, and in facilities such as poultry farms where avian influenza has occurred, decontamination of the environment where infectious viruses have spread is essential, and decontamination work is carried out by workers wearing protective clothing (infection control clothing). In decontamination work, blood and bodily fluids from infected patients and livestock are scattered, so protective clothing needs to be waterproof, such as water pressure resistant, and there has been a latent demand for fast-acting antiviral properties from the perspective of preventing secondary infection to workers when removing the clothing. Patent Document 1 discloses an antiviral protective suit using a fabric made by laminating a resin film and a nonwoven fabric impregnated or coated with an antiviral agent. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Registered Utility Model No. 3158963 Gazette [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the antiviral protective clothing disclosed in Patent Document 1 is made of a fabric that is a laminate of nonwoven fabric and resin film, and therefore the fabric is not breathable, making it difficult to actively reduce humidity inside the clothing. Consequently, the comfort of wearing this protective clothing for long periods of time is poor, and there is a problem that it places a heavy burden on the worker.

[0005] This invention has been made in view of the problems described above, and aims to provide a nonwoven fabric that has excellent waterproofing and breathability, and also has excellent immediate antiviral effect, and protective clothing using this nonwoven fabric. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a nonwoven fabric comprising (1) fibers, cerium oxide nanoparticles and a resin composition and fibers, wherein the nanoparticles are fixed to the fibers, the nonwoven fabric comprises one surface and the other surface, the distribution rate of cerium elements on at least one surface is 10% or more, and the content of the nanoparticles in the entire nonwoven fabric is 0.5 to 2.5 g / m². 2 The nonwoven fabric is characterized in that the resin composition contains a thermosetting resin containing nitrogen atoms and has a water pressure resistance of 800 mmH2O or more. Furthermore, in the nonwoven fabric of (2)(1), it is preferable that the surface zeta potential of at least one of the aforementioned surfaces is 20 mV or higher. Furthermore, in the nonwoven fabric of (3)(1) or (2), it is preferable that the water contact angle of one of the surfaces is 110° or more. Furthermore, in any of the nonwoven fabrics described in (4)(1) to (3), the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) is 0.40 to 1.0 or higher. Furthermore, in any of the nonwoven fabrics of (5)(1) to (4), the resin composition further contains a binder resin, and the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms) is 2.0 to 10.0. Furthermore, the protective suit is made using one of the nonwoven fabrics described in (6)(1) to (5). [Effects of the Invention]

[0007] The present invention provides a nonwoven fabric that has excellent waterproofing and breathability, as well as excellent immediate antiviral effect, and protective clothing using this nonwoven fabric. [Modes for carrying out the invention]

[0008] [Cerium oxide nanoparticles] The nonwoven fabric of the present invention contains cerium oxide nanoparticles. By including cerium oxide nanoparticles, antiviral properties can be imparted to the nonwoven fabric.

[0009] The cerium oxide nanoparticles contained in the nonwoven fabric of the present invention are preferably composed of a mixture of cerium(III) oxide (Ce2O3) and cerium(IV) oxide (CeO2). In addition to the oxide form described above, cerium oxide may also be in the form of hydroxide or oxyhydroxide. The mixing ratio of cerium(III) oxide and cerium(IV) oxide can be calculated as the molar ratio of cerium(III) to cerium(IV) by X-ray photophotonography (XPS) or the like.

[0010] The cerium oxide nanoparticles contained in the nonwoven fabric of the present invention may further contain transition metals from groups 3 to 12 of the periodic table. These metals can be expected to improve performance by creating lattice defects when doped with cerium oxide nanoparticles by taking on valencies of 2+ to 3+, or by causing a change in the valency of cerium oxide through valency changes such as 0 and 1+, 1+ and 2+, and 2+ and 3+ in response to the redox potential.

[0011] These transition metals are readily doped with cerium oxide nanoparticles, and from the viewpoint of further improving antibacterial and antiviral activity, transition metals from the 4th to 6th period are preferred, with Ti, Mn, Fe, Co, Ni, Cu, Zn, Zr, and Ag being more preferred.

[0012] These transition metals can be added during manufacturing as salts such as carboxylates, organic acid salts such as sulfonates, phosphorus oxoates such as phosphates and phosphonates, inorganic acid salts such as nitrates, sulfates, and carbonates, as well as halides and hydroxides. Any of these that dissolve in the solvent used during manufacturing is acceptable.

[0013] The cerium oxide nanoparticles contained in the non-woven fabric of the present invention have appropriate hydrophilicity, and can form crystal nuclei of the nanoparticles or stably disperse the formed nanoparticles by forming a complex with metal ions or coordinating with hydroxyl groups. From this perspective, it is preferable to contain a stabilizer. As the stabilizer, it is preferable to use a basic amino acid, an alicyclic amine, an aromatic heterocyclic compound containing a nitrogen atom in the ring structure, a polymer having a heterocyclic amine skeleton, or a boron compound. From the perspective of low colorability when made into a dispersion, it is more preferable to use a boron compound.

[0014] Examples of the boron compound used as the stabilizer include the boron compound represented by the chemical formula (I). BRn(OR’) 3-n (I) In formula (I), n is an integer from 0 to 2, R represents any one of an alkyl group having 1 to 4 carbon atoms, a phenyl group or a tolyl group, and R’ represents any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group or a tolyl group. When there are multiple Rs or R’s, they may be the same or different from each other. The tolyl group may be any of the o-tolyl group, m-tolyl group or p-tolyl group. When there are multiple tolyl groups, they may be the same or different from each other.

[0015] As a more preferred embodiment of the boron compound used in the present invention, boric acid (in the general formula (I), n = 0, R = H, R' = H), boric acid ester (in the general formula (I), n = 0, R = H, R' = alkyl, etc.), boronic acid (in the general formula (I), n = 1, R = alkyl, etc., R' = H), boronic acid ester (in the general formula (I), n = 1, R = alkyl, etc., R' = alkyl, etc.), phosphonic acid (in the general formula (I), n = 2, R = alkyl, etc., R' = H), phosphonic acid ester (in the general formula (I), n = 2, R = alkyl, etc., R' = alkyl, etc.), and borate are included. In the present invention, borate refers to a general term including salts of boric acid or salts of metaboric acid, polyboric acid, etc. obtained by dehydration condensation of boric acid. Since these borates take an equilibrium state of boric acid and tetrahydroxyboric acid in an aqueous solution, they take the structure of boric acid represented by the general formula (I) in the solution. As the counter ion of boric acid in the borate, any ion such as lithium ion, sodium ion, potassium ion, ammonium ion, etc. can be used.

[0016] Examples of such boron compounds include boric acid; boric acid esters such as trimethyl borate, triethyl borate, tripropyl borate, triisopropyl borate, tributyl borate, and triisobutyl borate; and boronic acids such as methyl boronic acid, ethyl boronic acid, propyl boronic acid, isopropyl boronic acid, butyl boronic acid, isobutyl boronic acid, and phenyl boronic acid. Examples of borates include lithium salts, sodium salts, potassium salts, and ammonium salts of boric acid, metaboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid, hexaboric acid, and octaboric acid.

[0017] It is preferable that the content of boron element with respect to 1 mole of cerium element in the cerium oxide nanoparticles contained in the non-woven fabric of the present invention is 0.001 mole or more. On the other hand, it is preferable that the content is 10 moles or less, and more preferably 1 mole or less.

[0018] In the present invention, the content of boron element with respect to 1 mole of the cerium element refers to the value obtained by measuring and calculating according to the following method. (1) Using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray fluorescence device, perform EDX spectrum measurement. (2) For the obtained EDX spectrum, perform elemental quantitative analysis, and calculate the content of boron element with respect to 1 mole of cerium element from the ratio of the elemental peak intensities of cerium and boron.

[0019] In the non-woven fabric of the present invention, on one surface and the other surface, the distribution rate of cerium element on at least one surface is 10% or more. When the distribution rate of cerium element on one surface of the non-woven fabric of the present invention is less than 10%, the zeta potential is low, and the non-woven fabric may be inferior in antiviral immediate effectiveness. For the above reasons, the distribution rate of cerium oxide nanoparticles on one surface of the non-woven fabric of the present invention is more preferably 15% or more, and even more preferably 20% or more.

[0020] The non-woven fabric of the present invention has a content of cerium oxide nanoparticles with respect to the entire non-woven fabric in the range of 0.5 to 2.5 g / m 2 . When the content of cerium oxide nanoparticles with respect to the entire non-woven fabric is less than 0.5 g / m 2 , the non-woven fabric may not obtain sufficient antiviral properties and zeta potential. For the above reasons, the content of cerium oxide nanoparticles with respect to the entire non-woven fabric is preferably 0.5 g / m 2 or more, more preferably 0.75 g / m 2 or more, even more preferably 1.0 or more, and particularly preferably 1.25 g / m 2 or more. On the other hand, when the content of cerium oxide nanoparticles with respect to the entire non-woven fabric exceeds 2.5 g / m 2 , the waterproof properties such as the water pressure resistance of the non-woven fabric may decrease, and the water contact angle on one surface of the non-woven fabric may decrease. For the above reasons, the content of cerium oxide nanoparticles with respect to the entire non-woven fabric is 2.5 g / m 2Preferably, it is 2.25 g / m 2 It is more preferable that the following conditions apply: 2.0 g / m 2 It is even more preferable that the following conditions apply: 1.75 g / m 2 The following is particularly preferable.

[0021] [Resin composition] The nonwoven fabric of the present invention contains a resin composition in addition to the fibers and cerium oxide nanoparticles, which are the main constituent materials. By including the above resin composition, the cerium oxide nanoparticles can be supported and fixed to the fibers, which are the main constituent materials of the nonwoven fabric.

[0022] Furthermore, the above resin composition includes at least a thermosetting resin containing nitrogen atoms. Examples of nitrogen-containing thermoplastic resins used in the nonwoven fabric of the present invention include, but are not limited to, one or more selected from the group consisting of melamine resin, urea resin, polyurethane resin, polyimide resin, oxazoline resin, and isocyanate resin. Among these, using one or more selected from the group consisting of melamine resin, oxazoline resin, and isocyanate resin is particularly preferable from the viewpoint of improving the zeta potential of the nonwoven fabric of the present invention and enhancing its rapid antiviral effect.

[0023] In this context, rapid antiviral action refers to a logarithmic reduction in infectivity titer (viral inactivation index) of 2.0 or higher when, in the antiviral evaluation method described below, a virus solution is dropped onto a nonwoven fabric and a film is placed on top for 2 hours. The resin composition contained in the nonwoven fabric of the present invention preferably has a mass mixing ratio (resin composition / cerium oxide nanoparticles) of 0.40 to 1.0 with respect to the cerium oxide nanoparticles. If the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) is less than 0.40, the cerium oxide nanoparticles may easily detach from the nonwoven fabric. For the reasons above, the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) is preferably 0.40 or higher, more preferably 0.45 or higher, and even more preferably 0.50 or higher. On the other hand, if the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) exceeds 1.0, the waterproof properties of the nonwoven fabric, such as water pressure resistance, may decrease. For the reasons stated above, the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) is preferably 1.00 or less, more preferably 0.90 or less, and even more preferably 0.80 or less.

[0024] The resin composition contained in the nonwoven fabric of the present invention preferably further contains a binder resin. By containing the above-mentioned binder resin, the nonwoven fabric of the present invention has superior water resistance and other waterproof properties compared to when the above-mentioned resin composition is composed only of a thermosetting resin containing nitrogen atoms, and the water contact angle on one side of the nonwoven fabric of the present invention is also superior. Examples of binder resins include one or more selected from the group consisting of acrylic resin, epoxy resin, melamine resin, urethane resin, polyamide resin, polyimide resin, polyester resin, urea resin, phenolic resin, silicone resin, vinyl chloride resin, fluororesin, and non-fluorinated water-repellent resin, but is not limited to these and can be preferably applied. Here, examples of non-fluorinated water-repellent resins include hydrocarbon-based urethane resin, hydrocarbon-based acrylic resin, or mixtures of these resins. Among these, from the viewpoint of giving the nonwoven fabric waterproof properties, silicone resin, fluororesin, non-fluorinated water-repellent resin, or mixtures of these resins are more preferable.

[0025] The ionic properties of the binder resin contained in the nonwoven fabric of the present invention are preferably nonionic or cationic, and more preferably cationic. The nonionic or cationic nature of the binder resin results in good dispersion stability when mixed with cerium oxide nanoparticles contained in the nonwoven fabric of the present invention, improving the handling of the dispersion during the manufacturing process of the present invention, and consequently leading to superior productivity of the nonwoven fabric of the present invention.

[0026] The binder resin contained in the nonwoven fabric of the present invention preferably has a mass mixing ratio (binder resin / thermoplastic resin containing nitrogen atoms) of 2.0 to 10.0 with respect to the thermoplastic resin containing nitrogen atoms. When the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms) is within the above range, the waterproof properties of the nonwoven fabric of the present invention, such as water pressure resistance, and the water contact angle on one side of the nonwoven fabric of the present invention are excellent. For the above reasons, the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms) is preferably 2.0 or higher, more preferably 2.5 or higher, and even more preferably 3.0 or higher. On the other hand, the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms) is preferably 10.0 or lower, more preferably 8.0 or lower, and even more preferably 6.0 or lower.

[0027] [Non-woven fabric] The nonwoven fabric of the present invention contains fibers as its main constituent material. The fibers are not particularly limited as long as they do not impair the effects achieved by the present invention, but examples include: I. Cellulose fibers such as cotton, linen, and rayon; II. Animal fibers such as wool and silk; III. Synthetic fibers such as polyolefin fibers, polyester fibers, polyamide fibers, acrylic fibers, polyurethane fibers, and polyvinyl alcohol fibers; and IV. Inorganic fibers such as glass fibers, carbon fibers, and ceramic fibers. Among these, synthetic fibers are preferred because they are readily available, and polyolefin fibers are more preferred among them because they have excellent waterproofing properties such as water pressure resistance. Furthermore, irregular cross-section fibers and hollow fibers can also be preferably applied as fiber forms.

[0028] The nonwoven fabric of the present invention has one side and another side. Here, one side refers to the side of the nonwoven fabric of the present invention that contains cerium oxide nanoparticles with a cerium element distribution rate of 10% or more. If both sides of the nonwoven fabric of the present invention satisfy the above conditions, one of the two sides shall be designated as one side and the opposite side as the other side. When the nonwoven fabric of the present invention is used in products such as protective clothing, high antiviral performance can be obtained by positioning the one side so that it comes into contact with a larger number of pathogens such as viruses and bacteria. Here, for example, in the case of protective clothing using the nonwoven fabric of the present invention, since it is envisioned to be used for treating infectious disease patients and for livestock disease control, it is preferable that the one side constitutes the outer surface of the clothing and the other side constitutes the inner surface of the clothing.

[0029] The nonwoven fabric of the present invention preferably has a surface zeta potential of 20 mV or higher on at least one side. Having the surface zeta potential of one side of the nonwoven fabric of the present invention within the above range results in a high degree of rapid antiviral efficacy on at least one side of the nonwoven fabric of the present invention. The surface zeta potential of the first side is preferably 20 mV or higher, more preferably 25 mV or higher, and even more preferably 30 mV or higher. To achieve the desired surface zeta potential, as described above, means such as setting the content of cerium oxide nanoparticles in the entire nonwoven fabric within a specific range can be used.

[0030] The fibers contained in the nonwoven fabric of the present invention constitute a base material. Examples of this base material include, but are not limited to, resin-bonded dry nonwoven fabrics, thermal-bonded dry nonwoven fabrics, spunbonded dry nonwoven fabrics, meltblown dry nonwoven fabrics, needle-punched dry nonwoven fabrics, water-jet dry nonwoven fabrics, flash-spun dry nonwoven fabrics, electrospinning dry nonwoven fabrics, and laminated nonwoven fabrics thereof. There are no particular restrictions on the nonwoven fabrics that constitute the laminated nonwoven fabrics; the same type of nonwoven fabric may be laminated, or different types of nonwoven fabrics may be laminated. Furthermore, in addition to those described above, the base material may also be a wet nonwoven fabric manufactured by a wet papermaking method that can achieve uniform basis weight and thickness. Among these, nonwoven fabrics made by laminating spunbond dry nonwoven fabric, meltblown dry nonwoven fabric, and spunbond dry nonwoven fabric in that order (hereinafter sometimes referred to as SMS nonwoven fabric) and flash-spun dry nonwoven fabric are particularly preferable as base materials from the viewpoint of superior productivity, tensile strength, tear strength, and dustproof properties. Furthermore, in addition to the above reasons, SMS nonwoven fabric is even more preferable as the base material from the viewpoint of its superior breathability, which can reduce stuffiness inside clothing.

[0031] When the above-mentioned base material is an SMS nonwoven fabric or a flash-spun dry nonwoven fabric, the average fiber diameter of the meltblown dry nonwoven fabric or flash-spun dry nonwoven fabric constituting the SMS nonwoven fabric is preferably in the range of 0.1 to 5.0 μm. Having an average fiber diameter within this range results in excellent waterproofing properties such as water pressure resistance and breathability of the nonwoven fabric of the present invention. For the above reasons, the average fiber diameter of the fibers made of the olefin resin is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, and particularly preferably 0.7 or more. On the other hand, the average fiber diameter is preferably 5.0 or less, more preferably 4.0 or less, even more preferably 3.0 or less, and particularly preferably 2.0 or less.

[0032] The nonwoven fabric of the present invention preferably has a water contact angle of 110° or more on one side. Having a water contact angle of 110° or more on one side of the nonwoven fabric of the present invention within this range results in superior waterproofing properties such as water pressure resistance. For the reasons stated above, the water contact angle of 110° or more on one side of the nonwoven fabric of the present invention is preferable, more preferably 115° or more, and even more preferably 120° or more. In order to achieve the desired water contact angle on one side of the nonwoven fabric of the present invention, as described above, measures such as setting the content of cerium oxide nanoparticles in the entire nonwoven fabric within a specific range can be mentioned.

[0033] The nonwoven fabric of the present invention has a water pressure resistance of 800 mmH2O or higher. Since the water pressure resistance is within the above range, if the water pressure resistance of the nonwoven fabric of the present invention falls below 800 mmH2O, the waterproofing of the nonwoven fabric of the present invention will be inferior. For example, when the nonwoven fabric of the present invention is used in protective clothing, hazardous substances (or contaminants) may penetrate the inside of the protective clothing, potentially leading to infection with pathogens such as viruses and bacteria. Examples of hazardous substances include liquids containing pathogens (e.g., blood or bodily fluids) and airborne particles (e.g., aerosols). Of course, it may be applied to other uses as long as the required performance is met. For the reasons stated above, the water pressure resistance of the nonwoven fabric of the present invention is 800 mmH2O or higher, preferably 900 mmH2O or higher, and more preferably 1000 mmH2O or higher. Furthermore, in order to achieve the desired water pressure resistance of the nonwoven fabric of the present invention, as described above, measures such as setting the content of cerium oxide nanoparticles in the entire nonwoven fabric to a specific range can be used.

[0034] The thickness of the nonwoven fabric of the present invention is preferably 0.80 mm or less, more preferably 0.70 mm or less, even more preferably 0.60 mm or less, particularly preferably 0.50 mm or less, and especially preferably 0.40 mm or less. By setting the thickness of the fabric within the above range, excellent breathability is achieved.

[0035] In this invention, the thickness of the fabric can be measured using a dial thickness gauge (SM-1201L, manufactured by Teclock) under the conditions of a measuring area of ​​10 mmφ and a measuring load of 1.5 N.

[0036] The nonwoven fabric of the present invention may contain additives such as surfactants, to the extent that they do not impair the effects of this embodiment. As surfactants, any of cationic surfactants such as quaternary ammonium salts, anionic surfactants such as higher fatty acid salts and alkyl sulfate ester salts, amphoteric surfactants such as alkyl betaines, and nonionic surfactants such as polyoxyethylene sorbitan fatty acid salts and polyoxyethylene alkyl ethers can be applied, but cationic surfactants and nonionic surfactants are more preferred. The mixing ratio of the above additives is not particularly limited and can be adjusted arbitrarily as long as the antiviral performance and antibacterial performance are not significantly impaired. On the other hand, in applications where water pressure resistance is required for the fiber base material containing cerium oxide nanoparticles of the present invention, such as fabrics used in protective clothing, the mixing ratio of surfactant to cerium oxide nanoparticles of the present invention (surfactant / cerium oxide nanoparticles) is preferably 0.02 or less, more preferably 0.01 or less, and even more preferably 0.002 or less, as it can reduce the water pressure resistance and water contact angle of the base material. It is especially preferable not to add surfactants or the like.

[0037] The nonwoven fabric of the present invention may be given functions to the extent that they do not impair the effects of this embodiment. For example, it may be given water-repellent, oil-repellent, blood barrier, virus barrier, abrasion-resistant, antistatic, flame-retardant, antibacterial, and antifungal properties. Methods for giving functions to the nonwoven fabric include using coating equipment such as a size press coater, roll coater, blade coater, bar coater, and air knife coater, and these devices can be used on-machine or off-machine.

[0038] Furthermore, the nonwoven fabric of the present invention has excellent antiviral properties and can be suitably used in protective clothing. In addition, a nonwoven fabric made using the nonwoven fabric of the present invention can exhibit excellent antiviral properties. [Examples]

[0039] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited in any way to these examples.

[0040] [Measurement method] (1) Basis weight of nonwoven fabric Based on JIS L1096-2010, two 200mm x 200mm test pieces were taken from the nonwoven fabric, and their mass (g) was measured. The mass per unit area (1m²) was then measured. 2 Mass per unit (g / m³) 2 The values ​​were calculated, and their average was determined.

[0041] (2) Distribution of cerium element on one side The cerium element distribution on one side of the nonwoven fabric was measured using SEM-EDX (energy-dispersive X-ray fluorescence). The SEM-EDX system used was a Hitachi High-Technologies Corporation SU3800 scanning electron microscope equipped with an Oxford Instruments Xplore EDS detector. Spectrum measurements were performed at an acceleration voltage of 15 keV. Qualitative analysis of the obtained spectrum was then conducted to analyze the cerium distribution.

[0042] (3) Content of cerium oxide nanoparticles in the entire nonwoven fabric Five 200mm x 200mm test pieces were taken from the nonwoven fabric and each was vacuum-dried at 90°C and 0.1kPa or less for 24 hours. Using a thermogravimetric differential thermal analyzer (TG / DTA6200, EIKO Instruments), each nonwoven fabric was held at 100°C for 5 minutes, then heated to 500°C at a rate of 10°C / min, and held at 500°C for 8 hours to induce thermal decomposition. The mass of the residue after thermal decomposition was used as the mass of cerium oxide, and the amount of cerium oxide per unit area (1m²) was determined. 2 Mass per unit (g / m³) 2 The following values ​​were calculated. The average of each calculated value, rounded to the third decimal place, was used as the content of cerium oxide nanoparticles in the entire nonwoven fabric.

[0043] (4) Surface zeta potential of one side of the nonwoven fabric Five 1.5cm x 3.5cm test pieces were taken from the nonwoven fabric, and each was placed in a flat cell with one side of the nonwoven fabric facing the electrode. A monitor particle (polystyrene latex) solution diluted 250 times with NaCl solution was injected into the cell, and electrophoresis was performed using a zeta potential, particle size, and molecular weight measurement system (ELSZ-2000ZS, manufactured by Otsuka Electronics Co., Ltd.) (sampling time: 400 μs, measurement angle: 15°, scattering intensity: 10000 cps or more, number of accumulations: 10, temperature: 25°C, cell constant: 66000 cm²). -1 ) was measured.

[0044] (5) Water contact angle of one side of the nonwoven fabric A DropMasterDMs-400 manufactured by Kyowa Interface Science Co., Ltd. was used as the contact angle meter, and measurements were performed using the droplet method (test solution: 2 μL of distilled water, measurement time: 5000 mS after dropping the test solution, analysis method: θ / 2 method, n: 10).

[0045] (6) Mass mixing ratio of resin composition to cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) A 200 mm x 200 mm test piece taken from the nonwoven fabric was placed in a beaker containing 200 mL of water at 50°C, ultrasonically cleaned for 30 minutes, and then vacuum-dried at 90°C and below 0.1 kPa for 24 hours. The dried nonwoven fabric was placed in a beaker containing 200 mL of toluene at 110°C, ultrasonically cleaned for 30 minutes, and then vacuum-dried at 90°C and below 0.1 kPa for 24 hours. The weight of the obtained residue was measured to the fifth decimal place, and the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) was calculated using the following formula (1).

[0046] ((Weight of obtained residue / 0.04) - (Content of cerium oxide nanoparticles) / (Content of cerium oxide nanoparticles) Equation (1) The above measurement was performed five times, and the arithmetic mean of the obtained values ​​was taken as the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles).

[0047] (7) Mass mixing ratio of binder resin to nitrogen atom-containing thermoplastic resin (binder resin / nitrogen atom-containing thermoplastic resin) The residue obtained by the measurement method in item (6) above was placed in a beaker containing 200 mL of dimethylformamide at 70°C, ultrasonically washed for 30 minutes, and then vacuum dried at 90°C and 0.1 kPa or less for 24 hours. The weight of the obtained residue was measured to the fifth decimal place, and the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) was calculated using the following formula (1).

[0048] (Weight of residue obtained in (6) / 0.04) / ((Weight of residue obtained in (6) / 0.04) - (Weight of residue obtained in (7) / 0.04))) Equation (2) The above measurement was performed five times, and the arithmetic mean of the obtained values ​​was taken as the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms).

[0049] (8) Water pressure resistance Based on JIS L1092 Method A (low water pressure method), a hydrotester (FX-3000-IV, manufactured by TEXTEST) was used to apply water pressure to the test specimen at a pressure increase rate of 600 mm / min. The water pressure at the point when three water droplets were dispensed was measured three times. The arithmetic mean (mmH2O) of the fiber diameter obtained from the above measurements was calculated and rounded to the first decimal place to determine the water pressure resistance.

[0050] (9) Antiviral Nonwoven fabric was cut into 50mm x 50mm squares and placed in a humidified petri dish. 0.4 ml of virus solution (influenza virus) was dropped onto one side of the nonwoven fabric, and a 4cm x 4cm film (made of PP) was placed on top. The mixture was allowed to react for 2 hours and 24 hours. Then, PBS was added as a stopping solution to stop the reaction with the virus, and the virus on the nonwoven fabric was washed off and collected. This collected solution was used as the stock solution for viral titer measurement, and the infectivity titer was measured using the TCID50 method.

[0051] The antiviral activity was evaluated using the difference between the common logarithm of the viral infectivity titer when tested with the nonwoven fabric of the present invention and the common logarithm of the viral infectivity titer when tested with a nonwoven fabric that did not use cerium oxide nanoparticles (blank), as the viral inactivation index. A larger viral inactivation index indicates a higher immediate antiviral effect. Specifically, a logarithmic reduction in infectivity titer (viral inactivation index) of 2.0 or higher was judged to indicate effective antiviral performance.

[0052] [Example 1] (Forming of nonwoven fabrics) Polypropylene spunbond nonwoven fabric (basis weight 36g / m²) 2 On one side of the ) is a melt-blown nonwoven fabric made of polypropylene (basis weight 11g / m²), which serves as a barrier layer. 2 A laminate was obtained by directly molding (18 g / m²) onto the melt-blown nonwoven fabric side of this laminate. Next, a polypropylene spunbond nonwoven fabric (18 g / m²) was placed on the melt-blown nonwoven fabric side of the laminate. 2 After directly molding the material, it is embossed using an embossing machine at a temperature of 120°C and a pressure of 60 kg / m². 2 By laminating and integrating at a speed of 10 m / min, the basis weight becomes 65 g / m². 2 We obtained an SMS nonwoven fabric.

[0053] (Addition of cerium oxide nanoparticles) (1) Preparation of aqueous dispersion An aqueous dispersion of cerium oxide particles containing a boron compound (boric acid) was prepared by the following method: 50 ml of water was added to a round-bottom flask, 284 mg of boric acid was dissolved, and the pH was adjusted to 8.0 with sodium hydroxide. 1 ml of 10% by mass aqueous solution of cerium(III) nitrate hexahydrate was added and the mixture was stirred at room temperature for 10 minutes. Then, 1 ml of 1.2% by mass aqueous solution of hydrogen peroxide was added dropwise and the mixture was reacted at room temperature for 1 hour. After the reaction, nitric acid was added and the mixture was stirred at room temperature for 2 hours. The reaction solution was purified using an ultrafiltration membrane with a molecular weight cutoff of 10 kD to obtain a dispersion containing nanoparticles of cerium oxide surface-treated with boric acid. This was diluted with water to a concentration of 5% by mass. This resulted in an aqueous dispersion containing 5% by mass of cerium oxide particles containing a boron compound.

[0054] (2) Preparation of coating agent The aforementioned aqueous dispersion, thermosetting resin ("Nikalac MX-035" manufactured by Sanwa Chemical Co., Ltd.), and binder resin ("Unidyne XF-5007" manufactured by Daikin Industries, Ltd.) were mixed with pure water according to the chemical formulation A shown in Table 1. To this mixture, 0.55 wt% of a surfactant ("CPC monohydrate" manufactured by Tokyo Chemical Industry Co., Ltd.) was added to obtain the paint composition.

[0055] [Table 1]

[0056] [Table 2]

[0057] (3) Application of coating agent The polypropylene spunbond nonwoven fabric (basis weight 36 g / m²) that constitutes the SMS nonwoven fabric 2 The coating agent was die-coated onto one side of the material at a line speed of 1 m / min and a coating liquid discharge rate of 9.2 mL / min. After die-coating, the material was dried at 130°C for 3 minutes using an air-through method to obtain the nonwoven fabric of Example 1.

[0058] Table 3 shows the composition and physical properties of the nonwoven fabric obtained in Example 1.

[0059] [Example 2] The nonwoven fabric of Example 2 was obtained in the same manner as in Example 1, except that the coating liquid discharge rate for the die coating treatment was set to 5.8 mL / min. The composition and physical properties of the obtained nonwoven fabric of Example 3 are shown in Table 2.

[0060] [Example 3] The nonwoven fabric of Example 3 was obtained in the same manner as in Example 1, except that the coating liquid discharge rate for the die coating treatment was set to 13.8 mL / min. The composition and physical properties of the obtained nonwoven fabric of Example 3 are shown in Table 3.

[0061] [Example 4] The nonwoven fabric of Example 4 was obtained in the same manner as in Example 2, except that the chemical solution formulation was changed to Formulation B. The composition and physical properties of the obtained nonwoven fabric of Example 4 are shown in Table 3.

[0062] [Example 5] The nonwoven fabric of Example 5 was obtained in the same manner as in Example 2, except that the drug solution formulation was changed to Formulation C. The composition and physical properties of the obtained nonwoven fabric of Example 5 are shown in Table 3.

[0063] [Example 6] The nonwoven fabric of Example 6 was obtained in the same manner as in Example 2, except that the drug solution formulation was changed to Formulation D. The composition and physical properties of the obtained nonwoven fabric of Example 6 are shown in Table 3.

[0064] [Example 7] The nonwoven fabric of Example 7 was obtained in the same manner as in Example 2, except that the chemical solution formulation was changed to formulation E. The composition and physical properties of the obtained nonwoven fabric of Example 7 are shown in Table 4.

[0065] [Example 8] The nonwoven fabric of Example 8 was obtained in the same manner as in Example 2, except that the chemical solution formulation was changed to formulation F. The composition and physical properties of the obtained nonwoven fabric of Example 8 are shown in Table 4.

[0066] [Example 9] The nonwoven fabric of Example 9 was obtained in the same manner as in Example 2, except that the chemical solution formulation was set to formulation G. The composition and physical properties of the obtained nonwoven fabric of Example 9 are shown in Table 4.

[0067] [Example 10] The nonwoven fabric of Example 10 was obtained in the same manner as in Example 2, except that the drug solution formulation was set to formulation H. The composition and physical properties of the obtained nonwoven fabric of Example 10 are shown in Table 4.

[0068] [Example 11] The nonwoven fabric of Example 11 was obtained in the same manner as in Example 2, except that the drug solution formulation was designated as Formulation I. The composition and physical properties of the obtained nonwoven fabric of Example 11 are shown in Table 4.

[0069] [Example 12] The nonwoven fabric of Example 12 was obtained in the same manner as in Example 2, except that the nonwoven fabric of Example 2 was a flash-spun nonwoven fabric with a basis weight of 44 g / m2. The composition and physical properties of the obtained nonwoven fabric of Example 12 are shown in Table 4.

[0070] [Table 3]

[0071] [Table 4]

[0072] [Comparative Example 1] Comparative Example 1 nonwoven fabric was obtained in the same manner as in Example 1, except that the coating liquid discharge rate for the die coating treatment was set to 1.2 mL / min. The composition and physical properties of the obtained Comparative Example 1 nonwoven fabric are shown in Table 5.

[0073] [Comparative Example 2] Comparative Example 2 nonwoven fabric was obtained in the same manner as in Example 1, except that the coating liquid discharge rate for the die coating treatment was set to 19.5 mL / min. The composition and physical properties of the obtained Comparative Example 2 nonwoven fabric are shown in Table 5.

[0074] [Comparative Example 3] Comparative Example 3 nonwoven fabric was obtained in the same manner as in Example 2, except that the coating agent was subjected to mangle treatment. The composition and physical properties of the obtained Comparative Example 3 nonwoven fabric are shown in Table 5.

[0075] [Comparative Example 4] Comparative Example 4 nonwoven fabric was obtained in the same manner as in Example 2, except that the thermoplastic resin was "Meikanate CX" manufactured by Meisei Chemical Industry Co., Ltd. The composition and physical properties of the obtained Comparative Example 4 nonwoven fabric are shown in Table 5.

[0076] [Table 5]

[0077] In Examples 1 to 12, we were able to obtain nonwoven fabrics with excellent waterproofing and immediate antiviral properties.

[0078] On the other hand, Comparative Example 1 had excellent water resistance but poor immediate antiviral effect. Comparative Example 2 had excellent immediate antiviral effect but poor water resistance. Comparative Example 3 had excellent water resistance but poor immediate antiviral effect. Comparative Example 4 had excellent water resistance but poor immediate antiviral effect.

Claims

1. A nonwoven fabric containing fibers, cerium oxide nanoparticles, and a resin composition, The nonwoven fabric has one side and the other side, and the distribution rate of cerium element on at least one side of the nonwoven fabric is 10% or more. The content of the cerium oxide nanoparticles relative to the entire nonwoven fabric is 0.5 to 2.5 g / m². ２ And, The resin composition consists of a thermosetting resin containing at least nitrogen atoms. Water pressure resistance of 800 mmH ２ A nonwoven fabric characterized by being 0 or greater.

2. The nonwoven fabric according to claim 1, wherein the surface zeta potential of at least one side of the nonwoven fabric is 20 mV or more.

3. The nonwoven fabric according to claim 1 or 2, wherein the water contact angle of one side of the nonwoven fabric is 110° or more.

4. The nonwoven fabric according to any one of claims 1 to 3, wherein the mass mixing ratio of the resin composition to the cerium oxide nanoparticles (resin composition / cerium oxide nanoparticles) is 0.40 to 1.00 or more.

5. The above resin composition contains a binder resin, The nonwoven fabric according to any one of claims 1 to 4, wherein the mass mixing ratio of the binder resin to the thermoplastic resin containing nitrogen atoms (binder resin / thermoplastic resin containing nitrogen atoms) is 2.0 to 10.

0.

6. A protective suit made using the nonwoven fabric described in any one of claims 1 to 5.

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