Antibacterial resin, antibacterial fiber, and processed article of the same

Abstract

To develop a novel anti-pathogen agent that does not require excitation means suitable for pathogen-eliminating resin which is an anti-pathogen agent utilizing biomass if possible, and a polymer containing the agent.SOLUTION: Provided is resin containing anti-pathogen agent consisting of bio nanocarbon (also known as biochar) obtained by carbonizing biomass, where the biomass is chaff, and a ratio of mass between silicon oxide and carbon is 5:95 to 20:80. The anti-pathogen agent exerts anti-pathogen effect via water-soluble medium when mixed and fixed to a polymer.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a decontamination resin and processed products such as threads processed from the resin. Here, the term "decontamination" means an action of removing or preventing inconveniences in life such as disease caused by contamination with microorganisms or viruses.

Background Art

[0002] When microorganisms or viruses grow excessively, they can cause various diseases or environmental degradation such as the generation of bad odors. For this reason, various decontamination means for removing and inactivating these microorganisms and viruses have been devised, but the situation is far from satisfactory. This is also evident from the COVID countermeasures, where we have no choice but to rely on alcohol, social distancing, and ventilation (see https: / / www.mhlw.go.jp / stf / seisakunitsuite / bunya / 0000164708_00001.html). Also, reducing pathogens by ventilation can be said to be a passive decontamination method on the premise that clean air that has not been contaminated is supplied. Here, the term "decontamination" was born from the concept of removing and inactivating pathogens spread by bioterrorism when bioterrorism is carried out by biological weapons etc. (see, for example, Non-Patent Document 1). For this reason, the development of methods for reducing pathogens throughout the environment has been desired. As such a method, it may be considered to apply a non-volatile decontamination agent to a wall surface or the like, but at present, such materials do not exist.

[0003] Even when taking all possible infection prevention measures as described above, it is impossible to prevent outbreaks of norovirus, epidemics of respiratory syncytial virus, and infections by Legionella bacteria, and the lack of decontamination means is undeniable ( see https: / / www.mhlw.go.jp / stf / seisakunitsuite / bunya / kansentaisaku.html). That is, it can be said that the development of new decontamination means has been desired.

[0004] Under such circumstances, as methods for decontamination, decontaminants such as alcohol, hypochlorous acid, chlorine dioxide, and photocatalysts such as titanium dioxide have been proposed (see, for example, Non-Patent Document 1). Compared with these, zeolites supporting metals such as silver have been developed as decontaminants with even higher decontamination activity (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). However, in these technologies, when these decontaminants are kneaded into a polymer, only the decontaminants present on the polymer surface work effectively, and the decontaminants in the polymer remain inactive. This is because the supported components such as silver exhibit a decontamination effect only when supported on a substrate such as zeolite, and in a situation where the substrate cannot move from within the polymer, the effect remains only on the surface.

[0005] On the one hand, as the global environment deteriorates with the increase in population, and grains and the like would lead to a large loss of carbon sources if discarded, the utilization of biomass resources has been desired (see, for example, Non-Patent Document 2). Among these, biochar produced from grain residues or wood as raw materials has been tried for use as a soil conditioner, and the goal of improving the carbon cycle has been attempted. Among biochars, those with a particle size in the nanometer range are particularly called bio-nanocarbon (also known as biochar), and various characteristic properties such as magnetism and conductivity may appear from their shape and composition, and have attracted attention. In particular, biochar obtained by burning rice husks contains silicon oxide derived from plant opal, and thus exhibits specific behaviors such as generating heat by microwaves (see, for example, Patent Document 4), and is expected to have a wide range of application fields. However, regarding biochar, it is known that adding it to soil changes the microbial environment (see, for example, https: / / doi.org / 10.1038 / s41598-022-10682-2 nature.com / scientificreports / ), but its antimicrobial effect is completely unknown. Also, biochar or biochar is a general term for materials carbonized using plants, and its structure is a composite of carbon, graphite, graphene, graphene oxide, etc., and sometimes contains additional metals such as silicon, calcium, and magnesium. Biochar (biochar) obtained from gramineous plants usually contains silicon compounds derived from plant opal and is usually called "rice husk silica" regardless of the carbon content. Also, it is known that the biochar obtained by burning rice husks has different contents of silicon sensitizers and carbon forms depending on the treatment method, and that its control is important (see, for example, Patent Document 5). In other words, it can be said that its shape, form, and composition greatly affect the properties of biochar.

[0006] That is, there has been a demand for the development of a novel anti-pathogen agent that does not require an excitation means suitable for a resin for pathogen decontamination, and preferably an anti-pathogen agent using biomass, and the development of a polymer containing the same.

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been made under such circumstances, and an object thereof is to provide a novel anti-pathogen agent that does not require an excitation means suitable for a resin for pathogen decontamination, preferably an anti-pathogen agent using biomass, and a polymer containing the same. Means for Solving the Problems

[0010] In view of such circumstances, the present inventors have developed a novel anti-pathogen agent that does not require an excitation means suitable for a resin for pathogen decontamination, preferably an anti-pathogen agent utilizing biomass, and have sought a polymer containing the same. As a result of intensive research efforts, such properties have been found in a polymer containing nano-sized biocarbon, leading to the completion of the invention. That is, the present invention is as shown below. In addition, such a novel anti-pathogen agent also utilizes biomass. Therefore, the present invention is as shown below. <1>A resin selected from Group A, and bio-nanocarbon obtained by carbonizing biomass (also known as biochar), wherein the biomass is rice husk and the mass ratio of silicon oxide to carbon is 5:95 to 20:80, and a resin for pathogen decontamination characterized by containing the bio-nanocarbon. Group A Polyalkylene resin, polyester resin, polyamide resin, alkyd resin <2>The resin for pathogen decontamination according to <1>, characterized in that when the bio-nanocarbon is mixed and fixed to the polymer, it exhibits an anti-pathogen effect through a water-soluble medium. <3>The resin for pathogen decontamination according to any one of <1> to <3>, characterized in that the pathogen is a virus, bacterium or fungus. <4>A processed product obtained by processing the decontamination resin according to any one of <1> to <3>. <5>The processed product according to <4>, wherein the processed product is a thread, film or air filter. Effects of the Invention

[0011] According to the present invention, it is possible to provide a novel anti-pathogen agent that does not require an excitation means suitable for a resin for pathogen decontamination, preferably an anti-pathogen agent utilizing biomass, and a polymer containing the same.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0013] The present invention relates to a resin and a molded article thereof, and is characterized by containing a resin selected from Group A and a bio-nanocarbon obtained by carbonizing biomass (alias; biochar), wherein the biomass is rice husk, and the mass ratio of silicon oxide to carbon is 5:95 to 20:80, and is mainly composed of a resin for pathogen decontamination. Group A Polyalkylene resin, polyester resin, polyamide resin, alkyd resin

[0014] As the resin serving as the main component, a thermoplastic resin is preferable, and examples thereof include polyalkylene resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon, and alkyd resins. Polyethylene may be either high density or low density. It is preferable to use only one kind of such resin, and its content is preferably 80 to 99.997% by mass, more preferably 85 to 99.996% by mass, of the total amount in the polymer for pathogen decontamination of the present invention.

[0015] The polymer for pathogen decontamination of the present invention is characterized in that the resin serving as the main body contains 20 to 0.003% by mass, more preferably 20 to 0.05% by mass, of bio-nanocarbon which is a decontaminant. The method of incorporating bio-nanocarbon into the polymer is to mix bio-nanocarbon into the melted resin, process it into pellets, and the pellets can be appropriately diluted and processed with resin pellets, or the pellets can be directly processed to manufacture products. These can be carried out according to conventional methods. This is because the production temperature of bio-nanocarbon is much higher than the melting point of the resin, and bio-nanocarbon exists sufficiently stably near the resin melting point.

[0016] In the polymer of the present invention, it is characterized by comprising bio-nanocarbon (synonymous with nano-sized biocarbon, biocarbon) as an anti-pathogen agent. The bio-nanocarbon is characterized by heating and carbonizing biomass and adjusting the particle size by pulverization. As the biomass to be used, biomass derived from gramineous plants is preferable, and examples thereof include rice husks such as rice and wheat, and plant bodies after harvesting the fruits. This is because it is preferable for the anti-pathogen agent of the present invention to contain silicon oxides such as silica and silicon carbide in its constituent components, and thus it is preferable to contain glass as plant opal. Based on these, it is also possible to appropriately contain biomass of other plants within the range where the mass ratio of silicon oxide to carbon is not changed. The bio-nanocarbon which is the anti-pathogen agent of the present invention can be obtained by heating such biomass in an electric furnace at 1500 to 4000 ° C, more preferably 2000 to 3500 ° C for 4 to 12 hours under weakly oxidizing conditions. As the weakly oxidizing conditions, it is possible to exemplify gently supplying a gas in which a small amount of oxygen is added to nitrogen at a mass ratio of 5:95 to 20:80, more preferably 7:93 to 15:85. Gently means leaving it to natural supply or flowing an air current of about 11 / min. Thus, after confirming that the silicon oxide is contained in the equivalent amount in the carbonized crude organism by FTIR, it is pulverized to a particle size of 100 to 500 nm, preferably 150 to 300 nm using a fine pulverizer such as a jet mill. At this time, if a predetermined amount of silicon oxide does not exist, there is a risk of powder explosion, so this point requires attention. When examining the particle size distribution of such bio-nanocarbon, two peaks, that is, a carbon peak and a silicon oxide peak exist. The silicon oxide peak appears at a smaller side than the carbon peak. The mass ratio of silicon oxide to carbon is 5:95 to 20:80, more preferably 10:90 to 15:85.

[0017] Biochar with such physical properties exhibits excellent anti-pathogenic effects against pathogens such as bacteria, viruses, and fungi. Examples of bacteria include pathogenic Escherichia coli, Legionella, Campylobacter, etc. Examples of viruses include non-enveloped viruses such as adenovirus, RS virus, norovirus, and enveloped viruses such as corona, influenza, herpes, etc. Examples of fungi include Candida, Trichophyton, etc.

[0018] The bio-nanocarbon, which is the anti-pathogenic agent, exerts an anti-pathogenic effect not only through direct contact with pathogens but also indirectly or through a medium around them. Since the growth of microorganisms is inhibited even when the leachate is added to the medium, it is considered that some substance with an anti-pathogenic effect is released or the surrounding environment is changed. Since the medium exhibits an electromagnetic wave shielding effect, it is clear that the surrounding electrical environment is changed. Therefore, when incorporated into a polymer, it can exhibit an anti-pathogenic effect extremely effectively, and neither activation by excitation etc. nor a driving force for elution is required.

[0019] The polymer for anti-pathogenic use of the present invention can be processed into a paint etc. by being pulverized into yarns, films, filters, coating flakes, fine particles according to a conventional method and mixed with a film-forming agent.

[0020] Examples are shown below to explain the present invention in more detail.

Example

Example 1

[0021] Bio-nanocarbon used in the resin of the present invention was produced according to the following procedure. 1.1 kg of wheat husks were placed in an electric furnace, and while gently flowing nitrogen containing 7% oxygen, they were kept at 2500 to 3000 ° C for 12 hours to carbonize, obtaining crude biocarbon. This was pulverized in a jet mill to obtain bionanocarbon, which is the antipathogen agent of the present invention, having an average particle size of 212 nm and containing 12% silicon oxide. FTIR is shown in Figure 1, particle size distribution diagram in Figure 2, and micrograph in Figure 3. From the photograph, a hierarchical structure was observed, and it was presumed to be a mixture of graphite, graphene, and silicene. In particular, a sharp peak was present at 1600 cm-1 to 1100 cm-1 in FTIR, suggesting the presence of a silicene oxide structure. This means that when producing such biocarbon, water can be added to the carbonized and burned rice husks, filtered to remove insoluble matter, and the structure can be confirmed by FTIR or the like to produce it.

[0022] The anti-pathogenic effect of the above-mentioned anti-pathogenic agent was confirmed by the following method. The four bacterial species used were E. coli, S. aureus and Candida albicans, and the procedure was as follows. 1. 0.1 ml of the bacterial solution was adjusted to 1 x 105 cells / mL in PBS solution (pH 7.0), inoculated onto Sabouraud dextrose medium, and cultured at 37°C for 24 hours. 0.1 ml of 2000 ppm biochar PBS solution (pH 7.0) was added to the plate. For the control, 0.1 ml of PBS was added to the plate. 2. After culturing for 48 hours, the absorbance of the plate at 680 nm was measured. 3. The removal rate was calculated using the following formula: Removal rate=100 * (Absorbance of control - Absorbance of sample) / Absorbance of control The results are shown in Table 1. It can be seen that it has an excellent anti-pathogen effect.

[0023] [Table 1]

[0024] <Comparative Example 1> The wheat husk was calcined while ventilating at 1000 °C to obtain biochar in the form of husk silica with a purity of 98%. This had no antibacterial effect on yeast and was not water-soluble.

[0025] <Comparative Example 2> The apple trunk was treated in the same manner as in Example 1 to obtain biochar with a carbon content of 99%. This had no antibacterial effect on yeast and was not water-soluble.

Example 2

[0026] 0.2% of the bio-nanocarbon and 99.8% of polyethylene were heated, melted, and mixed at 180 °C, and pellets were produced using a pelletizer.

[0027] The anti-pathogen effect of the pellets was examined using yeast. The samples were prepared as follows. Sample 1 3 ml of water was added to 0.1 g of the pellet and immersed for 24 hours, and the immersion liquid was obtained by decantation and used as Sample 1. Sample 2 3 ml of water was added to the pellet of the residue of Sample 1 and immersed for 24 hours, and the supernatant was taken by decantation and used as Sample 2. Sample 3 3 ml of water was added to the pellet of the residue of Sample 2 and immersed for 24 hours, and the supernatant was taken by decantation and used as Sample 3. Sample 4 The pellet of the residue of Sample 3 was used as Sample 4. Sample 5 The pellet of Example 1 Sample 6 Water was used as a control. 200 μl of a 0.1% yeast solution was seeded in a Sabouraud dextrose medium and pre-cultured for 24 hours. 200 μl of each sample was added thereto and cultured for 24 hours, and colony formation and the like were observed to examine the effect on yeast. Further, a petri dish was placed between mobile phones emitting a spurious electromagnetic wave of 157 V / m to observe the absorption of the spurious wave. The results are shown in Table 2. From this, it can be seen that the leachate also has an anti-pathogen effect.

[0028]

Table 2

Example 3

[0029] The pellets of Example 1 were heated to a paste state and rolled out into a 0.02 mm film. Wrapping with this film kept the freshness of peaches longer than without any treatment. Industrial applicability

[0030] The present invention can be applied to functional resin products such as antibacterial filters, body odor-preventing clothing, and freshness-retaining films.

Claims

1. A resin for pathogen decontamination, comprising a resin selected from Group A and a bionanocarbon (also known as biochar) obtained by carbonizing biomass, the biomass being rice husks, and characterized in that the mass ratio of silicon oxide to carbon is 5:95 to 20:

80. Group A: Polyalkylene resins, polyester resins, polyamide resins, alkyd resins

2. The resin for pathogen decontamination according to claim 1, characterized in that when the bionanocarbon is mixed and fixed in a polymer, it exerts an anti-pathogen effect via a water-soluble medium.

3. The resin for pathogen decontamination according to any one of claims 1 to 3, characterized in that the pathogen is a virus, a bacterium or a fungus.

4. A processed product obtained by processing the decontamination resin according to any one of claims 1 to 3.

5. 5. The processed product according to claim 4, which is a thread, a film, or an air filter.

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