JP7270902B2 - Iodine-supported activated carbon - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Nihon Keizai Shimbun March 6 and 7, 2018 Nihon Keizai Shimbun November 28, 2018

TECHNICAL FIELD The present invention relates to an iodine-supporting activated carbon having antibacterial and antiviral properties by impregnating activated carbon with iodine.

Activated carbon is a porous substance consisting mostly of carbon (C), and has the property of adsorbing other substances in its pores. Activated carbon is formed by carbonizing wood, coal, or coconut shells and activating with water vapor or the like to form a large number of pores. Activated carbon is used for deodorization, water purification, adsorption of harmful substances, and the like, and can be reused by releasing the adsorbed substances by heating. As described in Patent Document 1, an invention is also disclosed in which iodine is added to contaminated water to sterilize it, and then iodine is adsorbed on activated carbon and recovered.

Also, iodine (I ₂ ) is one of the halogen elements and has strong bactericidal activity. Iodine dissolves relatively well in alcohol, and tincture of iodine dissolved in ethanol is also a disinfectant with strong bactericidal activity. However, since tincture of iodine is strongly irritating to the body, povidone-iodine, which is a mixture of polyvinylpyrrolidone and iodine to weaken the effect on the body, is used in mouthwashes and the like.

When iodine is dissolved in a potassium iodide (KI) aqueous solution or a sodium iodide (NaI) aqueous solution, it becomes a triiodide ion (I ₃ ⁻ ). can be supported in the pores of

Iodine-based disinfectants are effective against microorganisms such as viruses, fungi, and bacteria (tuberculosis and general bacteria) excluding some spore-forming bacteria, and are intermediate-level disinfectants with the same efficacy as chlorine-based disinfectants. is. However, iodine-based disinfectants may damage living organisms when sterilizing (bird) influenza viruses and the like. Therefore, when an iodine-based disinfectant is used, it is desired that the disinfectant be a disinfectant that sterilizes the living body in a non-invasive manner.

Avian influenza is an infectious disease of birds caused by infection with an avian influenza virus. Highly pathogenic avian influenza (HPAI), which is extremely pathogenic when it infects poultry such as chickens, poses a threat to the poultry farming industry. Humans have also been infected with H5N1 subtype viruses, and although the risk of infecting humans is low at present, there are concerns that they may mutate into viruses capable of infecting humans. Therefore, methods for inactivating the virus to lose its infectivity have been studied, and as described in Patent Documents 2 and 3, an invention for inactivating the avian influenza virus with liquid smoke has also been disclosed. .

As a disinfection method for livestock infectious diseases such as avian influenza, it is determined to use a slaked lime solution (10%) as a disinfectant. During an outbreak of avian influenza, slaked lime is used for epidemic prevention and disinfection. As described in Patent Document 4, an invention in which norovirus is inactivated with an aqueous solution containing calcium hydroxide (slaked lime) is also disclosed.

Slaked lime, or calcium hydroxide (Ca(OH) ₂ ), is a white powder in its solid state, and was scattered on athletic field lines and fields. there is In addition, calcium hydroxide loses its disinfecting effect when it reacts with carbon dioxide (CO ₂ ) to form calcium carbonate (CaCO ₃ ). It is considered impossible to prevent migration.

In order to solve the problem of invasiveness and persistence in disinfectants using slaked lime, the inventors developed iodine activated carbon (iodine-supporting activated carbon) that non-invasively kills microorganisms other than some spore-forming bacteria. Patent applications have been filed for the invention of , and the invention of an antibacterial/antiviral agent that has a long-lasting effect of inactivating viruses and bacteria (Patent Documents 5 and 6).

Japanese Patent No. 4368146 Japanese Patent No. 5236339 Japanese Patent No. 5507718 Japanese Patent No. 5763546 Japanese Patent Application No. 2017-102762 Japanese Patent Application No. 2018-032302

However, since activated carbon activated with steam exhibits alkalinity, iodide ions or iodate ions are likely to be generated when impregnated with iodine, and have the property of being eluted from the activated carbon. It is difficult to sustain for a long time.

In addition, iodine-supporting activated carbon is being mixed with various substances to give antibacterial and antiviral effects, but when mixed with substances containing alkaline components, the active state of iodine on the surface of the activated carbon is suppressed. , Antibacterial and antiviral effects may not be obtained.

Accordingly, an object of the present invention is to provide an iodine-supporting activated carbon capable of maintaining the active state of iodine supported on the activated carbon and sustaining antibacterial and antiviral effects for a long period of time.

In order to solve the above problems, the present invention provides a method for producing iodine-supported activated carbon by impregnating activated carbon with iodine, wherein the activated carbon in which alkaline components remain after activation is On the other hand, the alkaline component is removed by pre-acid treatment so that iodide ions or iodate ions are not generated when the iodine is impregnated, and the iodine is not released into the air or eluted into water. The elemental iodine is impregnated on the activated carbon so that it can be adsorbed onto the activated carbon so as to inactivate bacteria other than fungi and some spore-forming bacteria with the iodine.

Further, in the method for producing the iodine-supporting activated carbon, the iodine is sublimated and adsorbed in the pores of the activated carbon so as not to be in the state of iodine ions or iodate ions. It is characterized in that it is attached in the vapor phase.

Further, the iodine-supporting activated carbon of the present invention is characterized by being produced by the above method.

Further, the antibacterial/antiviral agent of the present invention is an antibacterial/antiviral agent in which the iodine-supporting activated carbon is added to a hygroscopic hydraulic inorganic substance or diatomaceous earth in which it is mixed, and the hydraulic inorganic substance The activated carbon is acid-treated in advance before the iodine is impregnated so that the inactivation of bacteria other than viruses, fungi and some spore-forming bacteria is not inhibited by the alkaline component of do.

Further, the antibacterial/antiviral agent is granulated so that the hydraulic inorganic material is used as a core material, and part of the iodine-supporting activated carbon scattered in the outer shell is exposed in the outer shell without being buried in the core material. , characterized in that

Further, the interior material of the present invention is characterized in that the antibacterial/antiviral agent is used.

According to the present invention, the active state of iodine supported on activated carbon can be maintained and the antibacterial and antiviral effects can be sustained for a long time. Elemental iodine can be supported on the activated carbon by acid-treating the activated carbon before impregnating it with iodine. Since iodine is not released into the air from activated carbon and is not eluted into water, it is non-invasive to the living body and can maintain antibacterial and antiviral effects for a long time. Even when iodine-supporting activated carbon is mixed with a substance containing an alkaline component, the active state of iodine on the surface of the activated carbon is not suppressed, and sufficient antibacterial and antiviral effects can be obtained.

1 is a diagram showing the sterilization principle of the iodine-supporting activated carbon of the present invention. FIG. 1 is a diagram showing a method for producing iodine-supporting activated carbon according to the present invention; FIG. 1 is a potential-pH diagram showing chemical forms of iodine to be supported on the iodine-supporting activated carbon of the present invention. FIG. FIG. 2 is a diagram illustrating a process of performing an acid treatment before supporting iodine on the iodine-supporting activated carbon of the present invention and then impregnating with iodine. FIG. 2 is a diagram showing the results of experiments on the sterilizing power of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of experiments on the antibacterial properties of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of experiments on the invasiveness of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of an experiment on the antibacterial properties when the iodine-supporting activated carbon of the present invention is mixed with calcium silicate. FIG. 2 is a diagram showing the results of an experiment on antibacterial properties when the iodine-supporting activated carbon of the present invention is mixed with diatomaceous earth. FIG. 2 is a diagram showing the results of an experiment on antifungal properties when the iodine-supporting activated carbon of the present invention is mixed with diatomaceous earth. FIG. 2 is a diagram showing the results of testing the virus inactivating ability of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of testing the virus inactivating ability of the iodine-supporting activated carbon of the present invention. FIG. 3 is a diagram showing the results of a comparative test with slaked lime on the persistence of the virus inactivating effect of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of a test on the durability of the disinfecting effect of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of a test on the durability of the disinfecting effect of the iodine-supporting activated carbon of the present invention. FIG. 2 is a diagram showing the results of testing the virus inactivating ability of the iodine-supporting activated carbon of the present invention when acid-treated. FIG. 2 is a diagram showing a granulated product mixed with iodine-supporting activated carbon according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the drawings. Components having the same function are denoted by the same reference numerals, and repeated description may be omitted.

First, the iodine-supporting activated carbon of the present invention will be described. FIG. 1 is a diagram showing the sterilization principle of iodine-supporting activated carbon. FIG. 2 shows a method for producing iodine-supporting activated carbon. FIG. 3 is a potential-pH diagram showing chemical forms of iodine supported on iodine-supporting activated carbon. FIG. 4 is a diagram illustrating a process in which acid treatment is performed before iodine is supported on the iodine-supporting activated carbon, and then iodine is impregnated.

As shown in FIG. 1, the iodine-supporting activated carbon 100 inactivates the microorganisms 200 adsorbed by the activated carbon 300 by supporting iodine 400 in the pores of the activated carbon 300 .

Microorganisms 200 include viruses, fungi (fungi) and bacteria. Viruses are on the order of about 50 nanometers (nm) in size and include (bird) influenza virus, norovirus, Ebola virus, foot-and-mouth disease virus, and human immunodeficiency virus (HIV). It should be noted that viruses are included in the microorganisms 200, although they cannot be defined as organisms. Fungi (molds) are fungi with a size of about 5 micrometers (μm), such as Trichophyton. Bacteria are about 1 micrometer (μm) in size, and include highly durable spore-forming bacteria such as Bacillus subtilis and Bacillus natto, and other general bacteria such as Mycobacterium tuberculosis, Escherichia coli, Vibrio cholerae, and Salmonella.

The iodine-supporting activated carbon 100 inactivates the microorganisms 200 adsorbed by the pores of the activated carbon 300 with the iodine 400 without invading living bodies such as humans and animals with the iodine 400 supported by the activated carbon 300 . It should be noted that inactivation is to kill the microorganisms 200 to lose their infectivity. Specifically, iodine cations oxidize cysteine, which is an amino acid residue of proteins in vivo, and iodine tyrosine and histidine, thereby altering proteins. Inactivation includes sterilization (virus), sterilization (virus), disinfection, sterilization (virus), or antibacterial (virus). That is, iodine 400 functions as a disinfectant, an antibacterial/antiviral agent, and the like.

For example, antiseptics include high-level antiseptics effective against most spores, medium-level antiseptics effective against Mycobacterium tuberculosis and most fungi and viruses, and most common bacteria and some fungi and viruses. There are low-level disinfectants that are effective in The order of resistance to disinfectants is spore-forming bacteria, viruses, tubercle bacilli, and general bacteria, in descending order. Iodine 400 is a medium-level disinfectant and is effective against microorganisms 200 except for some spore-forming bacteria that are resistant to iodine 400.

The activated carbon 300 is made by carbonizing and activating raw materials such as coconut husks, wood, coal, or petroleum to form a large number of pores. there is something Activated carbon 300 can adsorb iodine 400 up to about 1500 milligrams per gram (mg/g). For example, there are coconut shell activated carbon with an iodine adsorption performance of 1500 mg/g or less and spherical activated carbon with an iodine adsorption performance of 1200 to 1350 mg/g. In the case of charcoal, it is 300-400 mg/g.

In addition, the activated carbon 300 includes those with narrow pore entrances and many deep holes and those with wide pore entrances and many shallow holes. Pores include micropores with a diameter of 2 nanometers (nm) or less, mesopores with a diameter of 2 to 50 nanometers (nm), and macropores with a diameter of 50 nanometers (nm) or greater, but with an average of 1 to 50 nanometers (nm). It is preferably 5 nanometers (nm). Moreover, it is preferable that the specific surface area is 300 to 2000 square meters per gram (m ² /g).

As shown in FIG. 2, as an example of a method for producing activated carbon 300, first, a raw material 500 such as wood, coal, or coconut husks is pulverized or otherwise processed into a shape and size that can be easily processed in advance, and then the raw material 500 is crushed. It is carbonized 510 by heating at about 700 to 800° C. in the absence of oxygen. Then, it is activated 520 by reacting with water vapor (H ₂ O) or the like at about 900 to 1000° C., and purified by removing impurities and regulating the size. A large number of pores are formed in the activated carbon 300 by activation, and the adsorptive power is dramatically increased.

Thereafter, the activated carbon 300 is subjected to pH adjustment such as an acid treatment 530, and then (elemental) iodine 400 is impregnated into the pores of the activated carbon 300 to produce the iodine-supporting activated carbon 100. The iodine-supporting activated carbon 100 is mixed with a hydraulic inorganic substance such as calcium silicate, diatomaceous earth, or the like, and made into granules 550 to be used as a disinfectant or the like. Furthermore, it is used as an interior material 560 having antibacterial and antiviral properties by being added to building wall materials and the like.

As a method for supporting iodine 400 on activated carbon 300, first, simple iodine (I ₂ ) is dissolved in an aqueous potassium iodide (KI) solution or an aqueous sodium iodide (NaI) solution to produce triiodide ions (I ₃ ⁻ ). state. By impregnating the activated carbon 300 there, the iodine 400 is adsorbed in the pores of the activated carbon 300 and stably retained.

Triiodide ion [ ^-I =I ^{+ -I-} ] is a polyiodide produced by simple iodine ( ^-I =I ⁺ ) and iodide ion ( ^I- ). is supported on the activated carbon 300 in the state of elemental iodine ( ^−I =I ⁺ ⇔ ⁺ I= ^I− ), which is in an active excited state.

Further, although iodine 400 is solid at normal temperature and pressure, it also sublimes. Since iodine gas has a relatively weak bond between atoms, it may dissociate at high temperature to become monatomic molecules, and is carried on the activated carbon 300 in the state of elemental iodine (I).

Elemental iodine forms a two- to three-dimensional multi-bond network on the pore surfaces of the activated carbon 300 . Elemental iodine is similar to radicals ( ^* I) generated by irradiating simple iodine with ultraviolet rays, and is in a state of high chemical activity. By utilizing the hydrophobic, lipophilic, and catalytic properties of activated carbon 300, elemental iodine is held in activated carbon 300 in a stable state. Elemental iodine is intended to include simple iodine as well as monatomic molecules of iodine-400.

The iodine 400 is molecularly adsorbed (covalently bonded) in the pores of the activated carbon 300 by van der Waals force (intermolecular force bond). Furthermore, in the case of elemental iodine, a plurality of monoatomic molecules are strongly bonded physically and chemically by forming a network-like multi-bond (multiple bond). Therefore, the elemental iodine is carried on the activated carbon 300 in a state where it maintains its chemical activity for a long time, is not released into the air, and is not eluted into water.

The boiling point of iodine 400 is 184° C., and the iodine 400 vaporizes and desorbs from the activated carbon 300 above the boiling point. By volatilizing iodine 400 and the like from the used activated carbon 300 and impregnating it with iodine 400 repeatedly from activation, it can be reused as iodine-supporting activated carbon 100 . As long as there is no clogging of the pores of activated carbon 300 and no extreme reducing action, the sterilizing power of iodine 400 is maintained. Although iodine 400 has a pungent odor, it is tasteless and odorless when it is supported on activated carbon 300.

Iodine 400 has a fairly strong bactericidal activity in the form of simple iodine (I ₂ ) or elemental iodine ( ^* I), but loses its bactericidal activity in the form of iodine ions (I ⁻ ). Also, in the state of triiodide ion (I ₃ ⁻ ), iodate ion (IO ₃ ⁻ ), periodate ion (IO ₄ ⁻ ), etc., the sterilizing power is maintained, but since it is water-soluble, If it dissolves in water and diffuses, its bactericidal activity is impaired. Therefore, iodine 400 does not include iodine ions (iodide ions), triiodide ions, and (per)iodate ions.

As shown in FIG. 3, in the region 600 where the electric potential is in a reduced state, there is no antibacterial/antiviral effect due to the state of iodine ions. Also, in the region 610 where the potential is in an extremely oxidized state, the iodate ion or the like is in a state, so the oxidizing power (antibacterial and antiviral effect) is strong, but the effect does not last long because it is water soluble.

In the figure, in a triangular gray area 620 surrounded by a thick line, if the pH (hydrogen ion concentration) is neutral to acidic, the state of elemental iodine is maintained, and the oxidizing power (antibacterial/antiviral effect) is maintained. It also has a long-lasting effect because it is difficult to dissolve in water. In addition, when the pH becomes alkaline, it becomes in the state of iodate ion or iodide ion, so that the effect cannot be expected to last.

Activation of the activated carbon 300 includes a method using chemicals such as zinc chloride (ZnCl ₂ ) and a method of carbonizing raw materials and forming pores with steam (see FIG. 2). Steam activation is often used due to problems such as problems and corrosiveness.

As shown in FIG. 4( a ), in the case of the steam activation method, the ash of alkali metals (sodium, potassium, etc.) and alkaline earth metals (magnesium, calcium, etc.) contained in the raw material remains. 300 indicates alkaline (about pH 9-10). Specifically, when water vapor (H ₂ O) is bound to carbon (C), which is a raw material, and hydrogen (H ₂ ) is released by decomposition of the water vapor bound to the carbon surface, oxygen ( O) produces carbon monoxide (CO) to proceed the reaction (activation). The remaining alkali component 410 renders the activated carbon 300 alkaline.

Even if iodine 400 is impregnated with activated carbon 300 that has become alkaline, the antibacterial and antiviral effects are weak. Therefore, as shown in FIG. Alkaline component 410 is neutralized and dissolved with acid and removed from activated carbon 300 . Then, as shown in FIG. 4(c), if the activated carbon 300 is impregnated with iodine 400, leaching of the iodine 400 from the activated carbon 300 is suppressed, and elemental iodine having a high antibacterial and antiviral effect can be obtained. Iodine 400 is supported on activated carbon 300 .

The iodine-supporting activated carbon 100 has strong durability against low-concentration (about 2 to 5%) acids, alcohols, and organic solvents, but it has high durability against high-concentration alkalis, alcohols, organic solvents, and reducing agents. is weak. In addition, the iodine 400 in the iodine-supporting activated carbon 100 is not released into the air or dissolved in water, and the solubility in water is 0.05% or less as iodine ion (I ⁻ ), and iodine alone ( I ₂ ) is 0.05% or less.

In addition, the iodine-supporting activated carbon 100 is slightly corrosive to metals, which is lower than that of chlorine. The iodine-supporting activated carbon 100 has a pH of about 5 (acidic) in seawater, and even in a stainless steel corrosion resistance test in which it was immersed in seawater for 700 days, there was little change in pH and little corrosiveness to metals. That is, although the activity of the iodine-supporting activated carbon 100 lasts for a long time, it is less corrosive to metals.

Iodine 400 is stably retained in the iodine-supporting activated carbon 100, and nothing is released or eluted from the iodine-supporting activated carbon 100. Therefore, the iodine-supporting activated carbon 100 adsorbs without affecting surrounding objects. Iodine 400 inactivates only the infected viruses. That is, it is non-invasive to living organisms such as humans and animals, and passively inactivates microorganisms 200 such as viruses.

The amount of iodine 400 supported by the activated carbon 300 is adjusted by adjusting the balance between the adsorption capacity of the activated carbon 300 and the deactivation capacity of the iodine 400 . For activated carbon 300 that can support 1500 milligrams (mg/g) or less of iodine 400 per gram, the amount of iodine 400 supported is determined from the inactivation power of iodine 400 and the ability of activated carbon 300 to adsorb viruses and the like. Just decide.

For example, when 30 g of iodine 400 is supported on 100 g of activated carbon 300, the ratio of the remaining adsorbable surface area of activated carbon 300 is about 80%, and the ratio of inactivation power due to iodine 400 is about 20%. to some extent. Iodine 400 has a strong bactericidal power, and has a sufficient inactivating power even at about 20% of its saturated loading. If the inactivating power can be expected even with a small amount of iodine 400, the carrying rate of iodine 400 should be lowered to increase the ability to adsorb viruses and the like.

The amount of iodine 400 may be reduced so that the activated carbon 300 retains sufficient adsorption capacity, or the amount of iodine 400 may be increased to provide a strong deactivation effect. However, if the amount of iodine 400 carried is too large, the ratio of the surface area of the iodine-carrying activated carbon 100 capable of adsorbing viruses and the like decreases. The loading amount for inactivating avian influenza virus is preferably about 100 to 500 mg/g.

For example, birds infected with virus 200 such as avian influenza are fed feed mixed with iodine-supported activated carbon 100 and activated carbon 300 supported with iodine 400 to inactivate virus 200 in the bird's body and excrete it. It should be discharged with the object. If the avian influenza virus is inactivated non-invasively to the living body, the spread of virus infection can be suppressed or prevented, and the effect of reducing the slaughter, incineration or burial of large numbers of birds is expected. be.

Next, granules and interior materials mixed with iodine-supporting activated carbon according to the present invention will be described. The iodine-supporting activated carbon 100 may be added to a hygroscopic hydraulic inorganic substance or diatomaceous earth mixed with it. Hydraulic inorganic substances include calcium silicate, cement, gypsum, lime, calcium carbonate, and the like. Calcium silicate is a composition in which calcium oxide, silicon dioxide, water, etc. are combined, and is obtained from limestone and diatomaceous earth. Diatomaceous earth is a diatom shell whose main component is silicon dioxide. It is preferable to add a hydraulic inorganic substance to the wall material mainly composed of diatomaceous earth for adhesion to the object to be coated and for prevention of cracks after coating.

The hydraulic inorganic material mixed with the iodine-supporting activated carbon 100 may be made into a paste and sprayed onto interior materials such as wall materials, or granulated and embedded in interior materials. For example, when granulated, a hydraulic inorganic material is used as a core material, and granulated so that a part of the iodine-supporting activated carbon 100 scattered in the outer shell is exposed to the outer shell without being buried in the core material. When used as an interior material, a hydraulic inorganic substance is used as the main material, and a part of the iodine-supporting activated carbon 100 scattered on the surface layer is molded so as to be exposed to the surface layer without being buried in the main material. The iodine-supporting activated carbon 100 enables the interior material to have antibacterial and antiviral effects.

The iodine-supporting activated carbon 100 is acid-treated in advance before the iodine 400 is impregnated so that the effect of the activated carbon 300 is not inhibited by the residual alkaline component after the activation of the activated carbon 300 . Furthermore, since the hydraulic inorganic substance is hygroscopic, the effect of the iodine-supporting activated carbon 100 is not suppressed even by the alkali component of the hydraulic inorganic substance. Even if it is suppressed, the elemental iodine is activated enough to exert its antibacterial and antiviral effects. Elemental iodine is maintained in an active state as the acidity is stronger.

Next, the effectiveness of the iodine-supporting activated carbon of the present invention will be described. FIG. 5 is a diagram showing the results of experiments on the sterilizing power of iodine-supporting activated carbon. FIG. 6 is a diagram showing the results of experiments on the antibacterial properties of iodine-supporting activated carbon. FIG. 7 is a diagram showing the results of experiments on the invasiveness of iodine-supporting activated carbon. Note that activated carbon on which (elemental) iodine is supported is referred to as iodine activated carbon and is expressed as (IodAC).

In FIG. 5(a), (Ref) is when nothing is added to the culture solution of brilliant glycerin lactose bouillon (BGLB) medium used for testing E. coli, etc., and (AC) is when activated carbon that does not carry iodine is added. , (IodAC) is the result when iodine activated charcoal is added. Also, in FIG. 5(b), (pre-IodAC) is the result when the iodine-activated charcoal was immersed in the broth of bird feed for 6 hours and then washed with water. The components of the culture solution are calf bile powder, lactose, peptone, brilliant grin and the like.

As shown in FIG. 5(a), after storage at 30-35° C. for 27 hours, E. coli proliferated in (Ref) and (AC) and the culture became cloudy, but in (IodAC) the culture became clear. The condition is maintained, and strong bactericidal activity of (IodAC) is observed. In addition, as shown in FIG. 5(b), after storage at 30 to 35° C. for 26 hours, the culture medium (pre-IodAC) maintained a transparent state, and the strong bactericidal activity of (IodAC) was maintained. there is

In FIG. 6, (AC) is when iodine-free activated carbon is added to a standard agar medium generally used as a medium for measuring viable cell count, and (IodAC) is when iodine activated carbon is added. shows the results of After storage at 30 to 35°C for 22 hours, bacteria proliferated around (AC), and a circle of inhibition (halo) formed around (IodAC) indicating that the growth of bacteria was suppressed. and the antibacterial properties of (IodAC) are recognized.

In FIG. 7, (iodine I ₂ ) indicates the results when chicken gizzards were contacted with iodine, and (IodAC) indicates the results when iodine activated carbon was contacted. After standing at normal temperature for 8 hours, (Iodine I ₂ ) caused a reaction due to iodine attack at the contact site, but (IodAC) showed no reaction at the contact site, indicating no invasiveness.

Iodine-supported activated carbon kills microorganisms other than some spore-forming bacteria by the iodine that the activated carbon supports. It can be applied to various uses as an agent.

Next, the effects of the presence or absence of acid treatment in the iodine-supporting activated carbon of the present invention will be described. FIG. 8 is a diagram showing the results of experiments on antibacterial properties when iodine-supporting activated carbon is mixed with calcium silicate. FIG. 9 is a diagram showing the results of experiments on antibacterial properties when iodine-supporting activated carbon is mixed with diatomaceous earth. FIG. 10 is a diagram showing the results of experiments on antifungal properties when iodine-supporting activated carbon is mixed with diatomaceous earth.

In FIG. 8, calcium silicate powder and iodine-activated carbon (containing 30% iodine) on which elemental iodine is supported after being acid-treated with hydrochloric acid are uniformly kneaded in a beaker to form a tablet having a diameter of about 1 cm. Mold it into a sample. An E. coli solution was applied with a cotton swab to the surface of the solidified standard agar medium, and the sample was allowed to stand on the surface.

As shown in Fig. 8(a), when no acid treatment was applied, the inhibition around the sample was observed in both cases of 80% calcium silicate and 20% iodine activated carbon, and 50% calcium silicate and 50% iodine activated carbon. There are no circles, indicating that antibacterial properties are not observed. Moreover, as shown in FIG. 8(b), when the acid treatment was performed, there was a A zone of inhibition was observed, indicating that antibacterial properties were confirmed.

In FIG. 9, a paste of diatomaceous earth and iodine activated carbon (containing 30% iodine) on which elemental iodine is supported after acid treatment with hydrochloric acid are uniformly kneaded in a beaker, and the diameter is about 1 cm. to be used as a sample. An E. coli solution was applied with a cotton swab to the surface of the solidified standard agar medium, and the sample was allowed to stand on the surface.

As shown in FIG. 9(a), when acid treatment is not performed, there is no inhibition circle around the sample with diatomaceous earth of 50% and iodine activated carbon of 50%, indicating that no antibacterial properties are observed. In addition, as shown in FIG. 9(b), when acid treatment was performed, there was an inhibition circle around the sample with diatomaceous earth of 50% and iodine activated carbon of 50%, indicating that antibacterial properties were confirmed.

In FIG. 10, a case where only diatomaceous earth is applied and a case where diatomaceous earth mixed with iodine activated carbon is applied are prepared on a decorative board which is an interior material of a building, and Aspergillus niger is sprayed on the entire surface. It was allowed to stand in a space maintained at a humidity of 90% or more and a temperature of around 25°C, and the progress was observed after 4 months.

As shown in FIG. 10(a), in the case of diatomaceous earth alone, mold invades from around and begins to cover, but as shown in FIG. is preventing

Next, the results of testing the virus inactivating ability of the iodine-supporting activated carbon of the present invention are shown. 11 and 12 are diagrams showing the results of testing the virus inactivating ability of iodine-loaded activated carbon. FIG. 13 is a diagram showing the results of a comparison test between slaked lime and slaked lime regarding the persistence of the virus inactivating effect of iodine-supporting activated carbon. FIG. 14 is a diagram showing the results of a test on the durability of the disinfecting effect of iodine-supporting activated carbon. FIG. 15 is a diagram showing the results of a test on the durability of the disinfecting effect of iodine-supporting activated carbon.

As the activated carbon, (AC) uses coconut shell activated carbon with a particle size of 0.25 to 0.5 mm, and (BAC) uses spherical activated carbon with a particle size of 0.4 mm or less. (IodAC) is elemental iodine loaded (coconut shell) activated carbon and (IodBAC) is elemental iodine loaded spherical activated carbon.

Also, the activated carbon may support 10 to 50%, preferably about 30% of the weight of iodine. Incidentally, 30 g (30% by weight) of elemental iodine supported on 100 g of activated carbon is expressed as (IodAC-30).

Avian influenza virus was inoculated into the allantoic cavity of 10-day-old embryonated chicken eggs (SPF fertilized eggs), cultured at 35° C. for 2 days, and the allantoic fluid was collected to obtain a virus solution. In addition, the virus solution is used after calculating the infectious titer (EID ₅₀ ) of 50% embryonated egg. In addition, the virus strain is the H5 subtype low pathogenic avian influenza virus A/swan/Shimane/499/83 (H5N3) strain isolated from the feces of tundra swans that flew to Shimane Prefecture in 1983. It has been confirmed that high pathogenicity is acquired by substituting.

First, dry (AC), (IodAC-30) and (IodBAC-30) were weighed into a 15 mL or 50 mL tube, and the specific gravity of (AC) and (IodAC-30) was 1 by weight. 0.67 times the weight of sterilized distilled water was added to (IodBAC-30) and mixed.

Next, a virus solution was prepared with PBS (phosphate buffered saline) to about 10 ^7.5 EID ₅₀ /0.2 mL.

Next, (AC), (IodAC-30) or (IodBAC-30) and virus solution are mixed at a ratio of [1:10], [1:20], [1:40] or [1:100] The mixture was left to stand at room temperature for 2 minutes, 10 minutes or 1 hour to react, or ``continuously stirred at room temperature for 10 minutes or 1 hour to react''.

Next, the reacted solution was diluted in 10-fold steps with PBS, and 0.2 mL of each diluted step was inoculated into the allantoic cavity of three 10-day-old chicken eggs and cultured at 35° C. for 2 days.

Next, the allantoic fluid was collected, reacted with a 0.5% chicken erythrocyte suspension, and the presence or absence of virus multiplication was determined by agglutination of erythrocytes. The residual virus titer (log ₁₀ EID ₅₀ /0.2 mL) was obtained by calculating EID ₅₀ by the Reed and Muench method, and the lower the titer, the more the virus was inactivated.

As shown in FIG. 11(a), in the reaction between (IodAC-30) and [10 times the volume] of the virus solution, the residual virus titer was reduced to about 1/1000 in the "reaction for 2 minutes at rest". The residual virus titer was reduced to about 1/10,000 in the “reaction for 10 minutes of standing still”, and decreased to about 1/1,000,000 in the “reaction of standing for 1 hour”.

As shown in FIG. 11(b), in the reaction between (IodAC-30) and [20 times the volume] of the virus solution, the residual virus titer was reduced to about 1/100 in the "reaction for 10 minutes while standing". let me

As shown in FIG. 12(a), in the reaction of (IodAC-30) with [20 times the volume] and [40 times the volume] of the virus solution, the residual virus titer was greatly increased in the "reaction with continuous stirring for 1 hour". decreased.

As shown in FIG. 12(b), (IodAC-30) reduced the residual virus titer to below the detection limit in the "reaction for 10 minutes with continuous stirring" for [40 times the volume] of the virus solution, and [ 100 times the volume] of the virus solution, the residual virus titer was reduced to about 1/300 by "reaction with continuous stirring for 10 minutes". In addition, (IodBAC-30) reduces the residual virus titer to about 1/300 in the "reaction for 10 minutes with continuous stirring" for [40 times the amount] virus solution, and [100 times the amount] virus For the liquid, the residual virus titer was reduced to about 1/10 by "reaction for 10 minutes with continuous stirring".

(IodAC-30) and (IodBAC-30) show an inactivation effect against the avian influenza virus by continuous contact with continuous stirring, and it was confirmed that (IodAC-30) was particularly effective. rice field.

Furthermore, slaked lime and iodine activated charcoal are compared with respect to the persistence of the virus inactivating effect. Slaked lime (calcium hydroxide) exhibits strong alkalinity in its aqueous solution (lime water), and is used as a neutralizer or disinfectant for acidified rivers and soil. Slaked lime is sometimes used as a preventive measure against bird flu viruses.

After uniformly spraying slaked lime and (IodAC-30) on a paper waste at a density of 37.5 g and 500 g/m ² respectively, water equivalent to 2 mm of rainfall is sprayed every two days, and precipitation It was exposed to the atmosphere until the next day after treatment.

For slaked lime, samples were taken on the 3rd, 5th, 7th, 9th and 28th days, weighed 200 mg each in a 15 mL tube, added 3.8 mL of PBS and mixed, then 2000 rpm and centrifuged for 2 minutes. 2 mL of the supernatant was collected in a new 15 mL tube to give a final concentration of 2.5% during the reaction.

For (IodAC-30), samples were taken on days 10 and 28, 100 mg was weighed into each 15 mL tube, and 1.9 mL of PBS was added to give a final concentration of 2.5% during the reaction.

Avian influenza virus A/swan/Shimane/499/83 (H5N3) strain was inoculated into the allantoic cavity of a 10-day-old embryonated chicken egg (SPF fertilized egg), cultured at 35°C for 2 days, and then injected into the allantoic cavity. The collected liquid was used as a virus liquid. For the virus solution, the infectious titer (EID ₅₀ ) of 50%-developed chicken egg is calculated, and it is adjusted to about 10 ^7.5 EID ₅₀ /0.2 mL with PBS before use.

First, the slaked lime and (IodAC-30) described above were each mixed with an equal amount of the virus solution and allowed to react at room temperature for 10 minutes. Incidentally, (IodAC-30) was reacted with continuous stirring. As a negative control, PBS and virus solution were similarly mixed and allowed to react at room temperature for 10 minutes.

Next, the reacted solution was diluted in 10-fold steps with PBS, and 0.2 mL of each diluted step was inoculated into the allantoic cavity of three 10-day-old chicken eggs and cultured at 35° C. for 2 days.

Next, the allantoic fluid was collected, reacted with a 0.5% chicken erythrocyte suspension, and the presence or absence of viral growth was determined by agglutination of erythrocytes. The residual virus titer was obtained by calculating _EID50 by the method of Reed and Muench.

As shown in FIG. 13(a), in the case of slaked lime, from the first test result to the third day (3d) of precipitation treatment/air exposure, the residual virus titer was measured in the same way as unused slaked lime (0d). Although it decreased to about 1/100,000 or less, the antiviral effect disappeared on the 28th day (28d).

In addition, when looking at the 2nd to 5th surveys, it was found that the avian influenza virus inactivation effect was not stable on the 5th day (5d), and that the antiviral effect was not shown after the 7th day (7d). bottom.

As shown in FIG. 13(b), in the case of (IodAC-30), both the 10th day and the 28th day significantly reduced the residual virus titer to below the detection limit.

In addition, the pH (hydrogen ion index) and antibacterial properties of slaked lime and iodine activated carbon are compared. The pH was measured by adding 10 mL of water to about 0.5 g of each sample of slaked lime and (IodAC-30).

As shown in FIG. 14(a), in the case of slaked lime, a large pH change (decrease from alkaline to neutral) was observed from about 10 days, whereas in the case of (IodAC-30), the pH change was small. (remains acidic).

Regarding the antibacterial property, first, 12.42 g of soil (Escherichia coli) was added to 600 mL of BGLB solution, heated and stirred, and then centrifuged at 2000 rpm for 5 minutes to obtain a liquid medium.

Each sample was placed in a 50 mL test tube with a thickness of about 2 to 3 mm, mixed with 30 mL of liquid medium, and cultured at 36 ° C. for 43 hours. In the case of IodAC-30), it was confirmed that there was almost no turbidity and that it had antibacterial properties.

Next, the surface of the standard agar medium was uniformly coated with a BGLB liquid medium in which the coliform bacteria had grown, and each sample was placed there in a size of about 8 to 15 mmφ and cultured at 36°C for 1 to 2 days. The size of the inhibition circle (halo width) after standing was measured.

As shown in FIG. 14(b), in the case of hydrated lime, there was a small inhibition circle with a halo width of about 1.5 mm on the first day, but the inhibition circle disappeared after 2 to 3 days. On the other hand, in the case of (IodAC-30), a large inhibition circle with a halo width of about 3.5 mm was maintained for 20 days or more, confirming that the antimicrobial activity was sustained.

Slaked lime did not maintain its virus-inactivating ability for even one week under the conditions of precipitation and exposure to the atmosphere, whereas (IodAC-30) demonstrated its excellent virus-inactivating ability by stirring and reacting with the virus liquid. It was found that the activating ability hardly decreased for about one month, demonstrating that the iodine-supporting activated carbon of the present invention is an extremely excellent disinfectant.

As shown in FIG. 15, regarding the virus titer, the antiviral ability of slaked lime disappeared in 3 to 5 days, whereas (IodAC-30) did not decrease the antiviral ability for 20 days or longer. In other words, it was confirmed that the antiviral activity over time showed the same tendency as the antibacterial activity.

Next, with regard to virus inactivation ability, the effect of the presence or absence of acid treatment in iodine-supporting activated carbon will be described. FIG. 16 is a diagram showing the results of testing the virus-inactivating ability of iodine-loaded activated carbon when acid-treated. FIG. 17 is a diagram showing granules mixed with iodine-supporting activated carbon.

As test samples, (4) diatomaceous earth mixed with 40% by weight of activated carbon (particle size of 250 to 500 μm), (5) 40% by weight of iodine activated carbon (particle size of 250 to 500 μm, 30% by weight of iodine) ), (6) diatomaceous earth mixed with 40% by weight of iodine activated carbon (particle size 6 μm, supporting 30% by weight of iodine), (7) calcium silicate mixed with 30% by weight of activated carbon Granules, (8) calcium silicate granules mixed with iodine activated carbon at 30% by weight, and (9) calcium silicate granules mixed with iodine activated carbon at 50% by weight (see FIG. 17). do.

For the test samples (4) to (9), half the weight of each virus solution was mixed and allowed to react at room temperature for 10 minutes. After that, SCDLP medium was added and diluted 10-fold to terminate the reaction. A 10-fold serial dilution was performed with PBS, and 0.2 mL was inoculated into the allantoic cavity of three 10-day-old embryonated chicken eggs for each dilution step, and cultured at 35°C for 2 days. After culturing, allantoic fluid was collected, reacted with 0.5% chicken erythrocyte suspension, and the presence or absence of virus growth was determined by agglutination of erythrocytes. Since the diatomaceous earth and calcium silicate granules used for the wall material, which is the interior material, do not have much water absorbency, the amount of liquid was reduced and the virus liquid was reacted with half the weight of the sample.

As shown in FIG. 16, in diatomaceous earth containing iodine activated carbon of test samples (5) and (6), the residual virus titer was reduced to about 1/50,000 or less, and iodine of test samples (8) and (9) In the case of calcium silicate containing activated carbon, it was reduced to 1/1,000,000 to 1/5,000,000 or less, indicating that the residual virus titer was reduced to below the detection limit.

According to the present invention, the active state of iodine supported on activated carbon can be maintained and the antibacterial and antiviral effects can be sustained for a long time. Elemental iodine can be supported on the activated carbon by acid-treating the activated carbon before impregnating it with iodine. Since iodine is not released into the air from activated carbon and is not eluted into water, it is non-invasive to the living body and can maintain antibacterial and antiviral effects for a long time. Even when iodine-supporting activated carbon is mixed with a substance containing an alkaline component, the active state of iodine on the surface of the activated carbon is not suppressed, and sufficient antibacterial and antiviral effects can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to these. For example, the present invention can be applied to methods for preventing or treating infectious diseases in animals other than humans. Also, activated carbon carrying iodine and spore-forming bacteria may be used in combination. For example, when used in combination with activated carbon carrying Bacillus natto, which is a spore bacterium, other bacteria and viruses are sterilized while Bacillus natto remains alive, so the effect of improving the intestinal immunity of birds by Bacillus natto can also be expected. Furthermore, by spraying activated carbon carrying iodine and activated carbon carrying Bacillus natto in lakes and marshes inhabited by birds, the effect of improving blue-green algae and offensive odors can be expected.

100: Iodine-supporting activated carbon 200: Microorganisms 300: Activated carbon 400: Iodine 410: Alkali component 500: Raw material 510: Carbonization 520: Activation 530: Acid treatment 540: Iodine impregnation 550: Granules 560: Interior material 600: Region (iodine ion)
610: region (iodate ion)
620: Region (elemental iodine)

Claims (6)

A method for producing iodine-supporting activated carbon by impregnating activated carbon with iodine,
The activated carbon in which alkaline components remain after activation is subjected to an acid treatment in advance so that iodine ions or iodate ions are not generated when the iodine is impregnated, so that the alkaline components are removed, and then the iodine is released into the air. In the state of elemental iodine, which is in an excited state of activity , to the activated carbon so as not to be eluted in water and to be adsorbable to the activated carbon so as to inactivate bacteria other than viruses, fungi and some spore-forming bacteria with the iodine. to attach
A method for producing iodine-supporting activated carbon, characterized by: The polyiodide is impregnated with the activated carbon in the state of elemental iodine by the catalytic action of the activated carbon, or the iodine is sublimated and adsorbed in the pores of the activated carbon, so that the polyiodide is added to the activated carbon in the state of elemental iodine in the gas phase. to attach
The method for producing iodine-supporting activated carbon according to claim 1, characterized in that: Manufactured by the method of claim 1 or 2,
An iodine-supporting activated carbon characterized by: The iodine-supporting activated carbon according to claim 3 is an antibacterial/antiviral agent added to a hygroscopic hydraulic inorganic substance or diatomaceous earth mixed with it,
In order that the alkaline component of the hydraulic inorganic substance does not inhibit the inactivation of bacteria other than viruses, fungi and some spore-forming bacteria,
The activated carbon is previously acid-treated before the iodine is impregnated,
An antibacterial/antiviral agent characterized by: The hydraulic inorganic material is used as a core material, and the iodine-supporting activated carbon scattered in the outer shell is granulated so that part of it is exposed in the outer shell without being buried in the core material.
The antibacterial/antiviral agent according to claim 4, characterized in that: The antibacterial / antiviral agent according to claim 4 or 5 is used,
An interior material characterized by:

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