WO2013018512A1 - Agent for hardening and solidifying radioactive contaminated soil surface, radiation blocking agent, and method for prevention of scattering of radioactive substance from surface, decontamination and protection - Google Patents

Abstract

[Problem] To provide an agent for hardening and solidifying radioactive contaminated soil, said agent enabling the retention of a radioactive contaminated substance, which otherwise would easily scatter, and, in the case where the soil surface is to be removed, making the removal easy. To provide a method for the prevention of the scattering of a radioactive substance, decontamination and protection. [Solution] A silane-based hardening and solidifying agent which hardens and solidifies radioactive contaminated soil surface, said hardening and solidifying agent comprising a compound represented by chemical formula (1) as the main component together with a catalyst for hardening and solidifying the same. In chemical formula (1), R₁, R₂, R₃ and R₄ may be either the same or different and each represents hydrogen or a C_1-4 alkyl group.

Description

Radiation contaminated soil surface hardening / solidification / radiation shielding agent and surface scattering prevention and decontamination / protection method

The present invention provides a curing / solidifying / radiation shielding agent for fixing a soil surface on which radioactive pollutants are scattered and preventing the radioactive pollutants from being scattered and capturing and removing the radioactive pollutants and It relates to decontamination and protection methods to be used.

Due to nuclear power reactor accidents, radioactive pollutants are scattered and humans cannot live.
In such a case, in order to prevent further scattering of the scattered radioactive pollutants, for example, a synthetic resin emulsion solution made of a flying sand inhibitor cricoat made by Kurita Kogyo Co., Ltd. is sprayed and contaminated with radioactive pollutants. The surface is fixed and placed on the spot.

Further, when radioactive pollutants are scattered on the surrounding soil surface, when the radioactive pollutants are volatile substances, for example, as disclosed in JP-A-2004-243195, “soil A pipe is embedded in the pipe, high-temperature superheated steam is jetted from the pipe into the soil, the pollutants in the soil are volatilized, and the volatiles are recovered and removed. '' Document resolution). However, if the pollutant is not a volatile substance, the contaminated surface soil is scraped off manually by human naval tactics or using heavy equipment such as a shovel car, and then removed from one place outside. It is known that decontamination of radioactive pollutants is performed by collecting in a place and removing the surface soil of the contaminated part.

However, in the case of radioactive pollutants, in order to avoid radioactive damage to workers, such as scraping the soil surface, each worker is required to wear radiation protective clothing. Therefore, it is necessary to perform work such as scraping only the surface of the soil. When using heavy machinery or the like, it is difficult to only scrape the surface soil of a few tens of centimeters only by scraping the surface.

JP 2004-243195 A

In view of the problems as described above, the present invention stops the radioactive pollutants that are easily scattered, and also hardens and solidifies the radioactively contaminated soil that can very easily remove the soil surface even when removed. -To provide radiation shielding agents and prevent radioactive substances from scattering and to provide decontamination / protection methods.

(1) The invention according to claim 1 of the present application is a silane-based curing / solidifying agent for curing / solidifying a radioactively contaminated soil surface, the main component compound represented by Chemical Formula 1 and a catalyst for curing / solidifying the same Hardening and solidifying agent for radioactively contaminated soil surface.

(In Chemical Formula 1, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, each being hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is 2 to 10)
(2) The invention according to claim 2 of the present application is characterized in that, in the curing / solidifying agent of claim 1, the catalyst is a hydrolyzable organometallic compound.
(3) The invention according to claim 3 of the present application is the curing / solidifying agent according to claim 2, wherein the hydrolyzable organometallic compound is one or more organic compounds selected from the group consisting of titanium, zirconium, aluminum, and tin. It is a metal compound.
(4) The invention according to claim 4 of the present application is the curing / solidifying agent according to any one of claims 1 to 3, further comprising three hydrolyzable substituents and one non-hydrolyzable substituent. And a compound represented by the formula (2):

(In Chemical Formula 2, R ₅ , R ₆ and R 7 may be the same or different, and are hydrogen, an alkyl group or an alkenyl group, and the bond between R ₅ O, R ₆₀ and R ₇ O and Si is It consists of a siloxane bond, and R ₈ is an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group (an epoxy group, a glycidyl group or an amino group) as a substituent.
(5) The invention according to claim 5 of the present application is the curing / solidifying agent according to any one of claims 1 to 4, further comprising two hydrolyzable substituents and two hydrolyzable substituents. It has the compound shown by Chemical formula 3 which has.

(In Chemical Formula 3, R ₉ and R ₁₁ may be the same or different, and are hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a siloxane bond; ₁₀ and R ₁₂ are an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group as a substituent.
(6) The invention according to claim 6 of the present application is the curing / solidifying agent according to any one of claims 1 to 5, further comprising isopropyl alcohol (IPA), an acrylic (methacrylic) ester copolymer, and a sub-oxidation Curing / solidifying agent containing lead or lead monoxide.
(7) The invention according to claim 7 of the present application is directed to the prevention and decontamination of radioactive materials on the radioactively contaminated soil surface by spraying the curing / solidifying agent of claims 1 to 6 onto the radioactively contaminated soil surface. Method.
(8) The invention according to claim 8 of the present application is a radiation protection material obtained by immersing and drying the curing / solidifying agent according to claims 1 to 6 in Japanese paper or a fiber material.
(9) The invention according to claim 9 of the present application is a radiation protection method using the radiation protection material of claim 8.
(10) The invention according to claim 10 of the present application is a mixture of the curing / solidifying agent of claims 1 to 6, isopropyl alcohol (IPA), an acrylic (methacrylic) ester copolymer, and tungsten or molybdenum. A radiation shielding agent.
(11) The invention according to claim 11 of the present application is a radiation shielding material obtained by applying or impregnating the radiation shielding agent of claim 10 to the surface of a paper material, a fiber material or a solid material.
(12) The invention according to claim 12 of the present application is a mixture of the curing / solidifying agent, isopropyl alcohol (IPA), acrylic (methacrylic acid) ester copolymer, and finely powdered tungsten according to claims 1 to 6. Neutron beam shielding agent.
(13) The invention according to claim 13 of the present application is a neutron beam shielding material obtained by applying or impregnating the surface of a paper material, a fiber material, or a solid material with the neutron beam shielding agent of claim 12.

The present invention has the following effects.
(1) A radioactively contaminated soil surface can be easily sprayed and can be used as a hardening / solidifying agent for hardening / solidifying the soil surface. As a result, after spraying the same agent to solidify the soil surface and remove the solidified soil surface, the section is clearly radioactively decontaminated because the radioactivity intensity clearly decreases.
This is because R4 in the chemical compound 1 contained in the curing / solidifying agent is not hydrolyzed even if the chemical compound 1 undergoes a subsequent hydrolysis / polycondensation reaction. It imparts water properties and, as a result, imparts water repellency to the solidified soil surface, and prevents radioactive substances in the soil from re-spraying around by water, wind, etc.

(2) Furthermore, radioactive substances can be captured and stopped in the solidified and removed soil, and radioactive decontamination can be easily performed by moving to other places while captured. That is, since the radioactivity is measured also from the curing / solidifying agent itself, there is an effect of capturing and taking in the radioactive substance also in the medicine itself to be used.
This means that the above-mentioned curing / solidifying agent itself has an unreacted bond portion in which the number of strong siloxane bonds of the main component of the compound is not enough, so that it is distributed in the form of “dangling”. It is presumed that it easily penetrates into the soil when it is done, softens the infiltrated part, and eventually traps the radioactive material in the solidified interior.

(3) In addition, regarding the prevention of re-scattering of these radioactive substances and the trapping inside, the selection and use amount of the organometallic catalyst used as the catalyst, the selection and use of the compound of Chemical Formula 2 and / or Chemical Formula 3 By arbitrarily selecting and preparing the amount, the spraying amount of the medicine, etc., the practitioner can prepare relatively freely, and there is an effect that it can be freely selected depending on the degree of contamination.

(4) Furthermore, since there is no need to use a silane coupling agent, the formation reaction of the soil surface to be solidified does not become non-uniform, and furthermore, the compound of Chemical Formula 1 etc. is easy to synthesize. Therefore, there is also an effect that it can be provided at a lower cost than those using a conventional organic / inorganic composite material.
In particular, since it is an inorganic material, it does not use boron ions, halogen ions, or the like. Therefore, in the prevention of scattering and decontamination / protection of radioactively contaminated soil according to the present invention, the used liquid is discarded as the ions. It is easier than the one using etc., and there is an effect that it does not cause other contamination.

(5) The most characteristic feature is that the drug used captures radioactive pollutants and does not easily flow out depending on water or the like, and the trapping time can be maintained. Therefore, the contamination does not spread while the contaminated soil or the like is accumulated while capturing radioactive contaminants and transferred to another place.
(6) Moreover, the radioactivity protection by Japanese paper etc. becomes possible by making the chemical | medical agent used in order to carry out the prevention of scattering of the radioactive contamination soil which concerns on this invention, and decontamination / protection into Japanese paper.

(7) And if the above-mentioned drug mixed with tungsten powder or molybdenum powder is applied or impregnated on Japanese paper, copy paper, Tyvek, the above-mentioned tungsten powder molten drug is applied to prevent the scattering of soil surface particles. The radiation shielding rate (reduction rate) in comparison with the impregnated comparative reference sample “No. 0 Sat” shows an excellent radiation shielding effect of 23.8% to 52.4%. The radiation reduction rate (shielding rate) in comparison with the collected soil (620 CPM) before impregnation with the liquid agent is a maximum of 48.4% to 67% as shown in “Radiation shielding rate with collected soil” in the above table. It has an excellent radiation shielding effect of .7% and has an excellent effect as a radiation shielding agent.

(8) Furthermore, in radiation shielding, a paper material and a fiber material laminated by applying and impregnating the above-mentioned agent mixed with tungsten powder (in Example 6, 16 laminated materials) are a pure tungsten plate having the same thickness. Equivalent or 1.5 times the gamma ray shielding effect of tungsten plate, not only the liquid agent to be coated and impregnated functions as a radiation shielding agent, but also the paper material and fiber material itself impregnated and impregnated should be used as a radiation shielding material Can do.
In addition, a paper material coated with and impregnated with the above-mentioned agent mixed with tungsten fine powder, a transcendent shielding paper A in which a plurality of fiber materials are laminated (in Example 8, 17 sheets are laminated) and boric acid ((H3BO3) 99.5%) Transcendental shielding paper B mixed with the above)) (in Example 8, the same 17 sheets laminated) has a neutron radiation shielding effect.

Figure 1 is a 200x magnified photograph of the surface of Japanese paper before applying the liquid agent. Fig. 2 is a 200x magnified photograph of the surface of Japanese paper after the application of the "Super Transcendent + Tungsten (3.5μm powder)" FIG. 3 is an enlarged cross-sectional photograph of the 200 × Japanese paper.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mode for carrying out the prevention of scattering and decontamination / protection of radioactively contaminated soil according to the present invention will be described in detail.

(Drugs used)
Examples of the agent used for carrying out the prevention of scattering and decontamination / protection of radioactively contaminated soil according to the present invention include, for example, curing and solidifying by the action of a catalyst in a silane-based liquid containing a compound represented by Chemical Formula 1 as a main component. Use possible drugs.

(In Chemical Formula 1, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, each being hydrogen or an alkyl group having 1 to 4 carbon atoms)

Examples of the solidifying agent for radioactively contaminated soil and the agent used for carrying out the method for preventing surface scattering and decontamination / protection according to the present invention include, for example, among four substituents of silicon atoms as shown in Chemical Formula 1 Infiltrate by spraying on the contaminated soil surface with a compound containing one substituted with a non-hydrolyzable substituent as a repeating unit, solidify the soil surface, and capture radioactive material scattered on the soil surface In addition to preventing re-scattering, the solidified soil surface is scraped to make it possible to decontaminate radioactive materials.

In addition, the raw material (monomer) for obtaining the compound of Chemical formula 1 is relatively inexpensive. Therefore, it is sufficient to use the chemical formula 1 compound without using an expensive so-called silane coupling agent. It is possible to form solidified with the above organic properties and with sufficient strength. Even when transporting the scraped surface soil to other places, the radioactivity trapped inside The substance does not leak out. As described above, the use of the compound represented by Chemical Formula 1 as a chemical used for carrying out the prevention of scattering and the decontamination / protection of the radioactively contaminated soil according to the present invention is extremely excellent.

The chemical | medical agent which has the compound shown by Chemical formula 1 as a main component is sprayed on the contaminated soil surface where the radioactive substance scattered the chemical used to carry out the prevention of scattering of radioactively contaminated soil and decontamination / protection according to the present invention. In addition, it is cured and solidified by the action of a catalyst. R ₁ , R ₂ and R ₃ in Chemical formula 1 may be the same or different and are each hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is preferably 2 to 10.

Such a compound can be obtained by condensing a monomer of n = 1 (for example, methyltrimethoxysilane). The main chain repeat is n = 1 to 10. If n is 11 or more, the number of alkoxy groups for polymerizing on the contaminated soil surface is insufficient when sprayed on the contaminated soil surface. This is because it is difficult to form solidified with sufficient strength.
When n = 1, that is, a monomer is used, it takes time to polymerize, and it takes time to form a solid with sufficient strength in a short time. Therefore, a condensate of n = 1 to 10, particularly n = 2 to 8 is preferable as a chemical agent used for carrying out prevention, decontamination and protection of radioactively contaminated soil according to the present invention.

In general, when a condensate such as Chemical Formula 1 is synthesized from monomers, it is technically impossible to accurately control the degree of polymerization. Therefore, the meaning of using, for example, n = 2 to 10, preferably n = 2 to 8, as the agent used for carrying out the prevention of scattering and decontamination / protection of the radioactively contaminated soil according to the present invention. In view of the distribution of the degree of polymerization, there is no use other than the use of a drug mainly containing n of 2 to 10, preferably mainly 2 to 8. For example, a compound in which n is 11 or more However, the numerical value of n should not be interpreted restrictively.

Specific examples of the compound represented by Chemical Formula 1 include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane. Examples thereof include condensates such as ethoxysilane, methyltripropoxysilane, and ethyltripropoxysilane. In addition, the compound of Chemical Formula 1 may be a product obtained by condensing only one kind of such monomers, or may be a product obtained by condensing two or more kinds of the above exemplified monomers.

The primary role of the non-hydrolyzable substituent (R ₄ ) in the compound of Chemical Formula 1 is to provide flexibility to the soil surface, but at the same time, to impart water repellency to the soil surface. For example, R ₄ may be an alkyl group. In general, the organic substituent has an organic property, that is, water repellency increases as the number of carbon atoms increases. However, when the carbon number is too large, distortion occurs in the soil surface due to steric hindrance and causes a decrease in strength of the film. Accordingly, the number of carbon atoms in the alkyl group and the type / amount of each monomer constituting the compound (condensate) of Chemical Formula 1 can be determined by conducting preliminary production tests while referring to the examples of the present specification. Is preferably determined. However, imparting water repellency to the soil surface can also be achieved by adding a compound of Chemical Formula 2 or Chemical Formula 3, which will be described later, and therefore it is essential that R ₄ in the compound of Chemical Formula 1 is an alkyl group. is not.

As a catalyst for curing and solidifying the compound represented by Chemical Formula 1, a commonly used catalyst can be used without any particular limitation. For example, in the case of an acid catalyst, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, formic acid or acetic acid can be exemplified. Examples of the base catalyst include ammonia, tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, ethanolamine, diethanolamine, and triethanolamine. When these ordinary catalysts are used, reaction water is allowed to coexist in order to cure and solidify the compound of Chemical Formula 1.

The chemical used for carrying out the prevention of scattering and the decontamination / protection of the radioactively contaminated soil according to the present invention thus contains the compound of Chemical Formula 1, the catalyst and the reaction water. In normal use, there is no particular problem. However, when this is stored for a long period of time, there is a problem that the drug is easily gelled by the reaction water. In order to solve this, it is preferable to use a hydrolyzable organometallic compound as a catalyst instead of the above-described ordinary catalyst. If a hydrolyzable organometallic compound is used, there is no need to coexist with reaction water, which is preferable for long-term storage stability.

When an organometallic compound is mixed with the compound of Chemical 1 to make a drug and sprayed onto the contaminated soil surface, moisture on the soil surface or inside or moisture in the air (humidity) is sucked and the organometallic compound hydrolyzes itself. At this time, a network is formed with the compound of chemical formula 1, and the chemical compound of chemical formula 1 is cured and solidified. As an organometallic compound preferably used in the chemical | medical agent used in order to implement scattering prevention of the radioactively contaminated soil which concerns on this invention, and decontamination / protection, what contains titanium, zircon, aluminum, or tin can be illustrated, for example. More specifically, tetrapropoxy titanate, tetrabutoxy titanate, tetrapropoxy zirconate, tetrabutoxy zirconate, tripropoxy aluminate, aluminum acetylacetonate, dibutyltin diacetate, dibutyltin dilaurate, etc. can be exemplified.

In addition, in order to uniformly mix the compound of chemical formula 1, the catalyst, and, in some cases, necessary reaction water, the chemical used for carrying out the prevention of scattering and decontamination / protection of radioactively contaminated soil according to the present invention, An organic solvent can be added. Examples of the organic solvent used for this purpose include alcohols. More specifically, methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol and the like can be exemplified. Also, the viscosity and drying rate of the drug can be adjusted by controlling the amount added.

For the purpose of such preparation, in particular glycols such as ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, methoxyethanol, propoxyethanol, butoxyethanol, methoxypropanol, ethoxypropanol, propoxypropanol Alternatively, it is preferable to use an organic solvent having a high viscosity or boiling point, such as cellosolves such as butoxypropanol, alone or in combination. Of course, the alcohols may be added simultaneously with one or more organic solvents having a high viscosity or boiling point. For the purpose of adjusting the viscosity and drying rate of the drug, the same effect can be achieved not only by the organic solvent but also by a surfactant.

In particular, since the glycols and cellsolves described above have a hydroxyl group in the molecule, they may be introduced into a network of siloxane bonds formed by the condensation reaction of the compound of formula 1. Since glycols and cellsolves are organic, the introduction of them increases the organicity of the resulting soil surface, that is, the organicity of the solidified soil surface.
Moreover, when the said chemical | medical agent contains the said organometallic compound (for example, tetrabutoxy titanium etc.) as a catalyst, the chemical change of (1) and (2) in the following reaction 1 occurs.

Reaction formula 1;
(1) Ti-OR + H2O → Ti-OH + ROH
(2) Ti-OH + RO-Si → Ti-O-Si
As described above, the strength of the solidified soil surface is improved by generating Ti—O bonds in the solidified soil surface. As described above, when an organometallic compound is used as a catalyst, not only the reaction water does not need to coexist, but also the strength of the solidified soil surface can be improved and a thin film of a silane compound can be applied to each fine particle. It can be formed.

(Modification of drug)
In addition, in addition to the compound of Chemical formula 1, in addition to the chemical compound of Chemical 1, the chemical used to carry out the prevention and decontamination / protection of radioactively contaminated soil according to the present invention, Compared with a coating material produced without using, it is possible to newly impart the organic property or the like possessed by the compound of Chemical Formula 2 or to increase the organic property or the like.

The compound of Chemical Formula 2 added for such a purpose is a compound consisting of 4 substituents, in which 3 are hydrolyzable substituents and the remaining 1 is non-hydrolyzable substituents.

In Chemical Formula 2, R ₅ , R ₆ and R ₇ may be the same or different and each is a monomer comprising hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkenyl group, and R ₅ O, R ₆ O and The bond between R ₇ O and Si is an oligomer composed of a siloxane bond, and R ₈ may contain an epoxy group or a glycidyl group in its molecule, an alkyl group having 1 to 10 carbon atoms, an alkenyl group, or It is a phenyl group.
Specific examples of the compound represented by Chemical Formula 2 include vinyltrimethoxysilane, phenyltrimethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, β- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane,-(methacryloxypropyl) triethoxysilane, γ-glycidoxypropyltriethoxysilane, aminopropyltriethoxysilane, Examples thereof include vinyltris (βmethoxyethoxy) silane and the like, and a condensate of about 2 to 10 molecules thereof.

The compound of Chemical Formula 2 may be two or more of such monomers. In the case of using a condensate of two or more molecules as the compound of Chemical Formula 2, a compound obtained by condensing two or more of these monomers may be used.
Moreover, in the chemical | medical agent used in order to implement scattering prevention and decontamination / protection of the radioactively contaminated soil based on this invention, in addition to the chemical | medical agent containing the compound of Chemical formula 1, or the chemical compound of Chemical formula 1 and the chemical compound of Chemical formula 2 In addition to the chemicals containing both, the chemicals added with chemical compound 3 can be used to improve the organic properties of chemical compound 3 compared to the coating material produced without using chemicals. It is possible to increase the properties such as organic properties.

The compound of Chemical formula 3 is a compound consisting of four substituents, two of which are hydrolyzable substituents and the other two of which are non-hydrolyzable substituents. In the chemical formula 3, R ₉ and R ₁₁ may be the same or different and each is a monomer comprising hydrogen, an alkyl group having 1 to 10 carbon atoms or an alkenyl group, and R ₉ O, R ₁₁ O and Si The bond is an oligomer composed of a siloxane bond, and R ₁₀ and R ₁₂ are an alkyl group, alkenyl group or phenyl group having 1 to 10 carbon atoms which may contain an epoxy group or a glycidyl group in the molecule. .

Specific examples of the compound represented by Chemical Formula 3 include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane. And a condensate of about 2 to 10 molecules thereof. The compound of Chemical Formula 3 may be two or more of these monomers, and also when two or more molecules of condensate are used, There may be.

By adding either chemical compound 2 or chemical compound 3 as described above to the drug, the organicity of the soil surface to be solidified can be increased, but both chemical compound 2 and chemical compound 3 are used as the drug. If added, the organicity of the solidified soil surface can be further improved, and as a result, the solidification strength of the soil surface can be further improved.

The compound of Chemical formula 2 and / or the chemical compound of Chemical formula 3 can be added to the drug in a range generally not exceeding 50% with respect to the compound represented by Chemical formula 1, which is the main component of the drug. preferable. If the total addition amount of both exceeds this range, when sprayed, it does not bind well with the main component compound 1, and the strength of the solidified soil surface may be insufficient. It is. Therefore, in the case of actually adding the chemical compound 2 and / or chemical compound 3, it is assumed that the strength of the soil surface solidified depending on the amount added, and the examples in the present specification are used. While referring to it, it is preferable to carry out a preliminary production test or the like, clarify the range of the addition amount that can achieve the object, and minimize the addition.

The primary role of the non-hydrolyzable substituents (R ₈ , R ₁₀ , R ₁₂ ) in the chemical compound 2 and chemical compound 3 is to give flexibility to the soil surface to be solidified. However, since these are organic substitutions such as alkyl groups, they also serve to impart water repellency to the soil surface to be solidified at the same time. Therefore, even if the soil surface cannot be shaved immediately after solidification, the radioactive material trapped inside by rainwater or the like does not leak out.

In general, when the number of carbon atoms of an organic substituent is too large, strain is generated on the soil surface solidified by steric hindrance, causing a decrease in strength. Accordingly, the number of carbon atoms of the organic substituent and the type / amount of each monomer constituting the compound (condensate) of Chemical Formula 2 and / or Chemical Formula 3 are preliminarily referred to with reference to Examples in the present specification. It is preferable to make a determination by performing an appropriate manufacturing test.

The siloxane bond with improved strength is also a so-called “hard” bond. Because of this “hardness,” the soil surface that has been solidified lacks flexibility, which may cause difficulties in scraping and transporting work. Therefore, the soil surface that has been solidified may sometimes require moderate flexibility.

Conventionally, sol-gel drugs generally used are tetraalkoxysilane (Si (OR) ₄ ) and oligomers thereof as a starting material, but these are completely hydrolyzed. When the soil surface is solidified, all four bonds of silicon atoms form a network of hard siloxane bonds, which are as hard as ceramics, but are not flexible and tend to collapse. Since there is a danger, it is more preferable to use a chemical comprising the above-mentioned chemical formula 1 and / or chemical formula 2 and / or chemical formula 3 as prevention of scattering and decontamination / protection of radioactively contaminated soil according to the present invention. is there.

This is because the chemicals used for carrying out the prevention of decontamination and decontamination / protection of radioactively contaminated soil according to the present invention are compounds of chemical formula 1 in which one of the four substituents of the silicon atom is not hydrolyzed It is because it is made into the main component of a medicine.
Moreover, in the chemical | medical agent used in order to implement scattering prevention and decontamination / protection of the radioactively contaminated soil based on this invention, the compound of Chemical formula 2 and the chemical compound of Chemical formula 3 which have one or two substituents which are not hydrolyzed, respectively. By adding to the drug, flexibility and the like can be arbitrarily increased.

Hereinafter, examples relating to the production of chemicals used for carrying out the prevention of decontamination and decontamination / protection of radioactively contaminated soil according to the present invention will be described in detail, but the examples are only examples, and The pharmaceutical production used for carrying out the prevention and decontamination / protection of such radioactively contaminated soil is not limited to these.

(Production of alkoxysilane condensate)
A methyltrimethoxysilane condensate (MTM), an ethyltrimethoxysilane condensate (ETM) and a methyltriethoxysilane condensate (MTE) were synthesized as follows.

(1) Synthesis of MTM To a 500 ml three-necked flask, 181 g of methyltrimethoxysilane, 50 g of methanol and 18 g of pure water were added and sufficiently stirred. Further, 2 g of 61% nitric acid was added, and the mixture was heated and refluxed for 3 hours with stirring. After the reaction was completed, the pressure in the reaction vessel was reduced while heating to remove methanol. The MTM thus obtained was mainly composed of 3 to 4 mer by gas chromatography analysis.

(2) Synthesis of ETM To a 500 ml three-necked flask, 200 g of ethyltrimethoxysilane, 50 g of methanol, and 18 g of pure water were added and sufficiently stirred. Further, 2 g of 61% nitric acid was added, and the mixture was heated and refluxed for 7 hours while stirring. After the reaction was completed, the inside of the reaction vessel was depressurized while heating to remove methanol. The ETM thus obtained was mainly composed of 3 to 4 mer by gas chromatography analysis.

(3) Synthesis of MTE To a 500 ml three-necked flask, 273 g of methyltriethoxysilane, 50 g of ethanol and 18 g of pure water were added and sufficiently stirred. Further, 2 g of 61% nitric acid was added and heated and refluxed with stirring for 12 hours. After the reaction was completed, the reaction vessel was depressurized while heating to remove methanol. The MTE thus obtained was mainly composed of 3 to 4 mer by gas chromatography analysis.
(4) As the above MTM, ETM, and MTE, the chemicals of chemical formulas 2 and 3 were combined based on chemical formula 1, and the chemicals No. 1 to N0.17 shown in Table 1 below (MTM, ETM, MTE) were obtained.

(1) Preparation of drug Using the alkoxysilane condensate synthesized in Example 1, 19.0 g of MTM containing these as main components, a solvent composed of 2 g of isopropyl alcohol and ethylene glycol, and tetrabutoxyzirconium as a catalyst The chemical | medical agent (No. 7 in the said Table 1) used in order to implement scattering prevention and decontamination / protection of the radioactively contaminated soil which concerns on a present Example by adding 0.8g was prepared.

(2) Dispersion of chemicals on contaminated soil surface In the prevention and decontamination / protection of radioactively contaminated soil according to the present invention, first, the radioactive material of any size is scattered on the contaminated soil surface. The drug (No. 7 in Table 1) was sprayed. Although the specific spraying method is not particularly limited, for example, it can be performed by spraying with a sprayer.

(3) Evaluation (a) Evaluation of surface solidification of radioactively contaminated soil Fukushima City Watari Elementary School, Fukushima City, Fukushima City, Hachimancho 120, Fukushima City: Tomotaka Takahashi In the schoolyard, during the 17th May 17th 2011 (16:30 11:30 to 17th 9:30), the area around the stand in the schoolyard was divided into 6 sections of 100cm x 100cm. On the other hand, the drug is divided into (a) no spraying, (b) 50 cc spraying, (c) 100 cc spraying, (d) 200 cc spraying, (e) 250 cc spraying, and at 10:00 am on May 16, 2011 Around 30 minutes, the drug was sprayed in the above amount with a sprayer and sprayed, and the radiation intensity of the compartment was measured.

The measurement was performed using a simple radiation measuring instrument “Hakarun (DX-200)” lent out free of charge as a school education support project by the Ministry of Education, Culture, Sports, Science and Technology.
The specifications of “Hakaru-kun (DX-200)” are as follows.
(A) Detector: Measurement radiation (gamma (γ) rays)
(B) Detector type: CsI (Tl)
(C) Sensitivity / counting efficiency: 10 cpm or more at 0.01 μSv / h (d) Indication error: ± 10%
(E) Energy range: 150 keV to 3 MeV
(F) Measuring part: Measuring range (0.001 to 9.999μSv / h)
(G) Display method: Digital rate display (h) Sampling time: 60 seconds (i) Display interval: Count value (moving average value) for 60 seconds is displayed every 10 seconds (j) Battery: Ni-Cd rechargeable battery ( k) Operating time: Approx. 10 hours (may be shortened due to Ni-Cd rechargeable battery characteristics)
(L) Memory function: None (m) Outline: Dimensions L x W x D (mm) (151 x 63 x 26)

Table 2 shows the measurement results.
After spraying the drug with a spray and spraying, radiation measurements were performed at the indicated times, but no change was seen in the radiation intensity.
However, in the sections (a) to (e) where the chemicals were sprayed, the soil surface was vitrified and solidified, and the soil did not flow out.
(Ii) Radioactive substance decontamination evaluation (1)

Table 3 shows the measurement of the radiation intensity of the section after removing the solidified surface in the sections (a) to (e) above. That is, after the measurement in Table 2 is completed, the soil surface of sections (a) to (e) is solidified, so the surface of the transplanting iron is cracked and cracked, and the tip of the transplanting iron is broken from the crack. And the solidified surface was removed.

The surface of the soil on which the above-mentioned chemicals are sprayed, and the solidified surface of the soil, the section surface of (a) is about 3 mm thick, the section surface of (c) is about 5 mm thick, and (d) The partition surface of (6) can be stripped off with a thickness of about 6 mm, and the partition surface of (e) can be stripped with a thickness of about 8-10 mm.

After removing the solidified surface and measuring the radiation intensity of the section again, it can be seen that the radiation intensity is clearly reduced. The measurement was performed using a simple radiation measuring instrument “Hakarun (DX-200)” as described above.

In addition, although the above-mentioned section (a) is slightly decreased, this is a result of removing the soil having a thickness of about 30 mm in order to compare the radiation intensity after removing the surface soil with other sections. A decrease in radiation intensity was observed.
(U) Radioactive substance decontamination evaluation (2)

Next, the capture state of the radioactive substance trapped inside the solidified drug itself was verified. For the verification, the soil surface of the solidified soil was brought home, and the above solidification was conducted at the Polymer Research and Evaluation Center Tokyo Office of the Japan Science Research Evaluation Organization (Shigeru Nagakayama, 2-22-13 Yanagibashi, Taito-ku, Tokyo). The soil was stored in a container, and 4 liters of water was poured into the container over 1 hour, and then the solidified state and radioactivity level of the soil were measured. Even after 4 liters of water was poured over 1 hour, no change was seen in the solidified state of the soil and there was no decrease in radioactivity level. The measurement was conducted at the same center (LUDLUM MEASUREMENES, INC DETECTOR: LUDLUM MODEL 44-9 SURVEY METER: LUDLUM MODEL 14C), and it was only about 1 hour after running water to 500 CPM before flowing water. Even when running water was poured into the soil, it was judged that there was no change in the state where the soil was capturing radioactive materials.

As Example 3, on July 7, 2011, the soil surface was solidified again in Koriyama City Sakeku Park (2-chome Fukasawa, Koriyama City, Fukushima Prefecture), and the radioactivity level was measured. The park has the highest radiation dose in Koriyama city, and has become a hot topic nationwide. According to reports, it is 3.8 (microsievert / hour 9 radiation level. is there.
(1) Preparation of drug (200B)

Since the No. 7 drug in Table 1 had a problem in mixing viscosity and was difficult to spray, a drug (200B) prepared by adjusting the viscosity based on the No. 7 drug was prepared. Since this drug is referred to as trial drug 200B in the applicant company, it is displayed as drug 200B. The preparation of the drug 200B is as follows.

First, 2.5 liters of the above-mentioned drug (No. 7), 2.5 liters of isopropyl alcohol (IPA), and a drug manufactured by Kyoyo Chemical Industry Co., Ltd. (58, Ijiri-machi, Ijita-cho, Uji, Kyoto) Name NK-310: Acrylic (methacrylic acid) ester copolymer 35 to 45% + isopropyl alcohol 55 to 65% contained) 10 liters of a drug (200B) was prepared. In addition, 20 g, 25 g, and 30 g of lead oxide (chemical formula Pb + PbO: the company's trade name “lead powder”) manufactured by NI Chemtech Co., Ltd. (19-6 Tsukihama Hamadera Nishimachi, Sakai-ku, Osaka, Japan) are mixed with the drug 200B. These were designated as Drug B, Drug C, and Drug D, respectively, while lead monoxide (chemical formula PbO: company name “Lizzage”) manufactured by NI Chemtech Co., Ltd. was added to 25 g, 30 g, and 40 g, respectively. After mixing, this was used as a sprayed drug as Drug E, Drug F, and Drug G. These are summarized in Table 4 below. In addition, A is for the comparison of the effect confirmation of the soil application mentioned later, and is displayed for convenience about the case where no medicine is used.

(2) Preparation of measurement samples In Example 3, as described above, 50 g of the soil surface was sampled at Koriyama City Sake Lid Park, and these were placed in a 3.2 g weight container. Samples (B to G) were prepared by spraying the above B to G chemicals on the soil. For comparison, a sample (A) in which no drug was sprayed was also prepared.

(3) Evaluation Regarding samples A to G prepared as described above, the total weight and the radioactivity level were measured, and the following results were obtained.

Measurements were taken with the above-mentioned measuring instrument (LUDLUM MEASUREMENES, INC DETECTOR: LUDLUM MODEL 44-9 SURVEY METER: LUDLUM MODEL 14C) at the Polymer Research and Evaluation Center Tokyo Office of the above scientific research evaluation organization. The radioactivity level of sample A to which no drug was sprayed was 620 CPM. However, for samples B to G to which the drugs B to G were sprayed, a decrease in the radioactivity level was observed.

As Example 4, the medicine C, the medicine D, the medicine E, and the medicine F created in Example 2 were each soaked in a 135 mm × 155 mm Japanese paper (weight 1.5 g) with a brush and dried sufficiently. A Japanese paper sample coated with these drugs C to D was placed on the comparative sample A, and the radioactivity level was measured from the sample. The results are shown in Table 6.

In Table 6, (a) shows the radioactivity level of Sample A without using any drug, and the level is 620 CPM. The radioactivity on the sample is covered with Japanese paper impregnated with the above drugs C to D. When the levels were measured, the radioactivity levels were reduced to 440 CPM, 304 CPM, 400 CPM, and 440 CPM, respectively, and radioactivity protection was confirmed.

In addition, radiation shielding for general paper that does not impregnate such drugs can shield alpha (α) rays in radiation even with a single sheet of paper, but it is measured in CPM measurement units as described above. It seems that the beta (β) and gamma (γ) rays that are used cannot be shielded with only a sheet of Japanese paper (http://www.hepco.co.jp/ato_env_ene/atomic/ explanation / knowledge-05.html). Therefore, the fact that the radioactivity level has been reduced as described above can be understood as that the radioactivity level has been reduced by the drug according to Example 3 soaked in Japanese paper. In the fourth embodiment, Japanese paper is used as a material. However, the material is not limited to Japanese paper, and may be a fiber material such as cloth as long as the above-described drug is infiltrated.

In Example 4 above, 181 g of methyltrimethoxysilane, 50 g of methanol and 18 g of pure water were added and stirred sufficiently, and further 2 g of 61% nitric acid was added and heated and refluxed for 3 hours with stirring. With respect to 2.5 liters of the alkoxysilane condensate MTM shown in No. 7 of Table 1 obtained by removing the methanol in the reaction vessel under reduced pressure (mainly 3 to 4 mer by gas chromatography analysis) , Isopropyl alcohol (IPA) 2.5 liters, acrylic (methacrylic acid ester copolymer 35-45% + isopropyl alcohol 55-65% containing) 10 liters was mixed, and this was named Drug 200B. 200 g of 100B is mixed with 20 g, 25 g, and 30 g of lead oxide (chemical formula Pb + PbO). Respectively, the drug B, the drug C, and the drug D are mixed with 25 g, 30 g, and 40 g of lead monoxide (chemical formula PbO), respectively. Each was coated with a brush on 135 mm x 155 mm Japanese paper (weight 1.5 g), soaked into the Japanese paper, dried, and these chemicals C to D were coated on the above-mentioned comparative sample A, and from above The radioactivity level was measured (measurement results are shown in “Table 6”).

However, since the chemicals used in Example 4 above are a mixture of lead suboxide (Pb + PbO) and lead monoxide (PbO), there are difficulties in using them directly in contact with the human body. Also, environmental and other impacts must be considered.
Therefore, in place of the above lead suboxide and lead monoxide, a tungsten or molybdenum molten chemical was applied and impregnated on Japanese paper, copy paper, and Tyvek (registered trademark), and the same measurement was performed.
The tungsten and molybdenum used were those manufactured by Toho Metals Co., Ltd., in the form of 3.5 μm powder and 3N standard (99.9% purity). Its physical properties are as follows.

The above-mentioned drug 200B is used as a translucent agent, and tungsten and molybdenum are mixed in a weight ratio of 1.5 times each to obtain “transcendental liquid agent + tungsten (3.5 μm powder)” and “transcendental liquid agent + molybdenum (3. 5 μm powder) ”solution, and this solution was applied to Japanese paper, copy paper, and Tyvex, respectively.
Tyvek (registered trademark) is a high-density polyethylene nonwoven fabric originally developed by DuPont. A sheet (nonwoven fabric) in which ultrathin polyethylene fibers of 0.5 to 10 microns are randomly laminated and bonded only by heat and pressure. (Http://tyvek.co.jp/construction/about/), has excellent moisture permeability and waterproof performance, and maintains outstanding strength and durability (same as above).

Samples were prepared by mixing tungsten powder or molybdenum powder with the translucent agent, and applying and impregnating each of the above Japanese paper, copy paper, and Tyvex, and conducting radiation shielding experiments.
That is, the following were prepared as measurement data samples.
・ No.1 Japanese paper “Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.1 Japanese paper” sample)
・ No.2 Japanese paper “Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.2 Japanese paper” sample)
・ No.3 Japanese paper “Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.3 Japanese paper” sample)
・ No.1 copy paper “Super Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.1 copy paper” sample)
・ No.2 copy paper “Super Transcendent + Molybdenum (3.5μm powder)” coated product (hereinafter referred to as “No.2 copy paper” sample)
・ No.1 Tyvek “Transcendant + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.1 Tyvek” sample)
・ No.2 Tyvek “Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.2 Tyvek” sample)
・ No.0 Soil “Transcendent + Tungsten (3.5μm powder)” coated product (hereinafter referred to as “No.0 Sat” sample)

The material and weight (10 cm × 10 cm) of each sample are organized as follows.
On top of that, three sheets of the above-mentioned Japanese paper (10 cm × 10 cm), two sheets of copy paper (10 cm × 10 cm), and two sheets of tyvek (10 cm × 10 cm) are prepared. The sheet was coated and impregnated with a solution obtained by mixing 1.5 times the weight of tungsten (3.5 μm powder) with the translucent solution (200B), and each measurement material sample was added to the “No. 1 Japanese paper” sample, “No. .2 Washi ”,“ No.3 Washi ”,“ No.1 Copy Paper ”,“ No.1 Tyvek ”, and“ No.2 Tyvek ”Samples. The liquid agent (200B) was coated and impregnated with a liquid agent obtained by mixing 1.5 times by weight of molybdenum (3.5 μm powder), and this was used as a “No. 2 copy paper” sample.

The “No. 0 Sat” sample is the “No. 1 Washi” sample, “No. 2 Washi” sample, “No. 3 Washi” sample, “No. 1 copy paper” sample, “No. 2” These are samples for comparison with the measured values of the “copy paper” sample, the “No. 1 tyvek” sample, and the “No. 2 tyvek” sample, and the above-mentioned July 7, 2011 used in Example 3 above. To prevent the scattering of soil particles during measurement on 50g of soil collected at Koriyama Sakeku Park (2chome, Koriyama City, Fukushima Prefecture) on the day, the above-mentioned “Transcendental Solution (50g) + Tungsten (3.5μm powder) (75g) ) "Is applied and solidified.

Measurements were made at the Tokyo Institute of Chemical Research, Polymer Testing and Evaluation Center Tokyo (Shigeru Kayama, Manager, 2-11-17 Shinonome, Koto-ku, Tokyo) on November 14, 2011, using a survey meter to measure the surface contamination density. went. GM (Geiger Muller) survey meter (1) DETECTOR LUDLUM MODEL 44-9 (manufactured by LUDLUM MEASUREMENTS, INC.), (2) SURVEY METER LUDLUM MODEL 14C (manufactured by LUDLUM MEASUREMENTS, INC.) used.
“DETECTOR LUDLUM MODEL 44-9” manufactured by LUDLUM MEASUREMENTS, INC. Is a radiation detector having a GM (Geiger-Muller type) pancake probe and has the following specifications.
(1) Application: α-ray, β-ray, γ-ray survey and inventory inspection (2) Detector: Pancake type halogen extinction GM
(3) the corresponding product: General survey meter, counting rate meter, counter (4) Window: 1.7 ± 0.3mg / cm ² Mica (5) Window Area: Active -15Cm2, open -12cm2
(6) Detection efficiency (4π geometric efficiency): C-14: 5%, Sr-90 / Y-90: 22%, Tc-99: 19%, P-32: 32%, Pu-239: 15% , I-125: 0.2%
(7) Sensitivity: 3,300 cpm / mR / hr (Cs-137 γ-ray)
(8) Energy response: Energy dependent (see Ludlum optional energy filter)
(9) Dead time: 80μs
(10) Operating voltage: 900V
(11) Connector: C type series (12) Configuration: Aluminum housing (color: beige coating) and stainless steel protective screen (79% open)
(13) Operating temperature range: -15 to 50 ° C
(14) Size: 4.6cm (high) x 6.9cm (width) x 27.2cm (long)
(15) Weight: 0.5kg
(16) Detection range: 0 to 2000 μSv / h

The “SURVEY METER LUDLUM MODEL 14C” is also designed to meet the requirements of nuclear medicine, and can detect alpha rays, beta rays, and gamma rays from 0 to 200 MR / HR with one or more external GMs (Geiger Muller Detector) or a scintillation detector, which has the following specifications.
(1) Supported detectors: Geiger-Muller tube, scintillation tube (2) Meter scale: Normal 0-2m R / hr and cpm, battery test (others are also acceptable)
(3) Multiplier: X0.1, X1, X10, X100, X1000
(4) Linear type: Reading within ± 10% of true value with detector connected (5) Connector: Series “C” (others are also possible)
(6) Internal detector: Geiger-Muller tube with energy compensation (only when used at 1000 times scale)
(7) Energy response: Within ± 15% of the true value between 60keV-3 MeV (use of internal detector only)
(8) Threshold value: 30mV ± 10mV
(9) Audio: Built-in unimov speaker (ON / OFF) (60dB or more at 2 feet)
(10) Calibration control: accessible from the front of the instrument (with protective cover) (11) High voltage: 900 V
(12) Threshold value: 30mV ± 10mV
(13) Response: Toggle switch to select FAST (4 seconds) or SLOW (22 seconds) of 10% -90% of last reading (14) Reset: Push button (15) Power to set to zero value: 2 Each "D" cell type battery (contains an externally connectable sealed compartment)
(16) Battery life: Usually over 1000 hours (battery status can be checked on the meter)
(17) Scale: 2.5 inch (6.4cm) arc, analog type 1mA
(18) Structure: Aluminum cast with beige polyurethane enamel coating (19) Temperature range: 4 ° F (-20 ° C) to 122 ° F (50 ° C) -40 ° F (-40 ° C) to 150 ° F ( (20) Dimensions: 6.5 inches (16.5cm) H X3.5 inches (8.9cm) W X8.5 inches (21.6cm) L
(21) Weight: 3.5 pounds (1.6kg) including battery

For the measurement method, on the comparative reference sample “No. 0 Sat”, other measurement data samples “No. 1 Japanese paper”, “No. 2 Japanese paper”, “No. 3 Japanese paper”, “No. 1 copy” Place "paper", "No.2 copy paper", "No.1 tyvek", "No.2 tyvek", apply the probe from above (unify the distance to the probe to 23mm), and after 2 minutes of irradiation Numerical values were measured. In addition, the measurement object was moved away from the probe, and the background was measured in the same manner.
The measurement results are shown below.

Here, “CPM (count per minute or count per minute)” is the amount of radiation expressed by the number of radiation measurements per minute (the number of radiation that has entered the radiation measuring instrument per minute). Measuring). It does not consider the impact on the human body. “100 CPM is equivalent to about 1 microsievert / hr”, “when 1 radiation is emitted from the radioactive material of 1 Bq (Becquerel) at every decay and all the detectors are captured. Indicates that a count rate of 60 CPM is an amount of radioactivity of 1 Bq. "

As is clear from Table X above, the measured value of the comparative reference sample “No. 0 Sat” sample was 420 CPM, and further, each measurement data sample “No. 1 Japanese paper” sample, “No. 2 By placing `` Washi '' sample, `` No.3 Washi '' sample, `` No.1 copy paper '' sample, `` No.2 copy paper '' sample, `` No.1 Tyvek '' sample, `` No.2 Tyvek '' sample, It was found that each had a radiation shielding effect such as 200 CPM to 320 CPM.

The above table X is a comparison with 420 CPM of the “No. 0 soil” sample, but the “No. 0 soil” sample prevents the scattering of soil particles during the measurement as described above. The above-mentioned “Transcendent (50 g) + Tungsten (3.5 μm powder) (75 g)” was applied and solidified, and originally, on July 7, 2011, Koriyama-shi Sakeku Park (Fukushima Prefecture) The soil is collected in Fukasawa, Koriyama City. A direct measurement of this soil is 620 CPM (see Sample A), as shown in Table 5 of Example 3 above, which is the above-mentioned “transluent (50 g) + tungsten (3.5 μm powder) ( 75 g) ”is reduced to 420 CPM by applying and solidifying, and further, by placing each sample thereon, it can be known that the measurement results of 200 CPM to 320 CPM are obtained.

Accordingly, the radiation shielding rate (reduction rate) in comparison with the comparative reference sample “No. 0 Sat” shows an excellent radiation shielding effect of 23.8% to 52.4%. The radiation reduction rate (shielding rate) in comparison with the collected soil (620 CPM) before the coating impregnation of the maximum is 48.4% to 67.67 as shown in “Radiation shielding rate with collected soil” in the above table. It has a radiation shielding effect of 7%.

In addition, about the Japanese paper used above, the Japanese paper before application of the liquid agent and the Japanese paper after application of the translucent agent + tungsten (3.5 μm powder) were verified with reference to a digital microscope 200 times photograph.
Fig. 1 is a 200x magnified photograph of the surface of Japanese paper before application of the liquid agent, Fig. 2 is a magnified photograph of the surface of the 200 paper of Japanese paper after application of the "translucent agent + tungsten (3.5 µm powder)", and Fig. 3 is a magnification of 200x. It is a Japanese paper enlarged cross-sectional photograph. In any case, it can be known that the liquid agent penetrates to the surface of the Japanese paper and the inside of the cross section.

Next, the “translucent agent + 3N tungsten (3.5 μm powder)” solution used in Example 5 was applied to glass fiber (manufactured by NICHIAS), kraft paper, Japanese paper, and each sample was cut into 15 cm × 17 cm. Each sample was prepared by stacking 16 sheets and fixing with tape. For each sample, methyltrimethoxysilane, methanol, pure water, and nitric acid used in Example 5 above were added, and after completion of the heating and refluxing reaction, methanol was removed and the alkoxysilane condensate MTM obtained by isopropyl was added to isopropyl. A solution in which 1.5 times the weight of 3.5 μm tungsten powder is mixed with the above-mentioned drug 200B in which isopropyl alcohol is mixed with an alcohol (IPA) and acrylic (methacrylic acid) ester copolymer (sometimes referred to as “transcendental liquid agent”). The sample coated and impregnated with glass fiber is called “W + glass fiber sample”, the sample coated and impregnated on the kraft paper is called “W + craft paper sample”, and the sample coated and impregnated on the same paper is called “W + Japanese paper sample”. did.
“Sample No.”, “Sample Name”, and “Thickness (mm)” of each sample are as follows.

A γ-ray irradiation experiment was performed on each sample, and the transmittance (shielding rate) was measured.
The measurement details are as follows.
○ Toho Metals Co., Ltd. Product Development Division Hiroaki Sakata Bringing γ-ray request irradiation for the above sample products (“Request irradiation” means that the supervisor of the cobalt 60 gamma irradiation room receives the request from the applicant. Implemented).
○ Measurement location: Cobalt 60 irradiation room, Faculty of Engineering, Nagoya University ○ Measurement date: 2011 / ll / 28 (Monday), 12/2 (Friday), 12/5 (Monday): 10.00-16.00
○ Measurement equipment: Co-60 irradiation device / Flicke dosimeter ○ Measurement purpose: Measure the radiation shielding rate of the sample ○ Use source: Co-60
○ Measurement method: A lead block is constructed 30cm from the radiation source. A sample is attached to the hole of the block and the dose of γ-ray is measured.
○ Irradiation time: 60 [min] x 3 times per sample ○ Evaluation method / evaluator: Based on the evaluation of Shigefumi Imai, the person in charge of irradiation / irradiation room management at the Cobalt 60 irradiation room at Nagoya University, using a Flicke dosimeter.
○ Samples used: Samples made by applying a liquid to each sample.
○ Reference value: When the sample is not installed, measure the dosimeter away from the irradiation window by the thickness of the sample. Measurement is one sample per day. The order of measurement was as follows.

○ Experimental results

○ Theoretical value: Pb · 10 [cm] is almost 100% shielded (99.996%) standard data and the theoretical value of the shielding rate from the density of tungsten is as follows (the theoretical value in this case is Both the density and purity are values for a 100% W plate.)

○ Consideration evaluation by Imai engineer The sample “W + glass fiber” has a numerical value that is almost the same (98%) as the W plate having the same thickness. Sample “W + kraft paper” has a numerical value of 150% higher than a W plate of equivalent thickness. The sample “W + Japanese paper” obtained a numerical value slightly inferior (81%) to the W plate having the same thickness.

As is apparent from the above discussion and evaluation, the gamma ray shielding according to this measurement is performed by laminating 16 samples of glass fiber impregnated with the above liquid agent, and β-ray shielding of a tungsten plate having a thickness of only 4.1 mm and an equivalent thickness. In the kraft paper impregnation, γ-ray shielding of 1.5 times that of a tungsten plate having a thickness of only 4.1 mm and an equivalent thickness was achieved.
Therefore, the liquid agent is effective as a radiation (γ-ray) shielding agent, and a paper material or a fiber material impregnated with this liquid agent has a very excellent effect as a radiation (γ-ray) shielding material.

As described above, Example 2 was carried out by spraying the drug on the soil surface to prevent re-scattering of radioactive substances on the soil surface and decontamination of the soil surface, but this was limited to the soil surface only. For example, even if it is a concrete surface, it is possible to prevent re-scattering of radioactive materials, as well as decontamination of radioactive materials, for example, by spraying cryogenic dry ice particles etc. It is clear that the surface can be peeled off and has a certain effect within the range of the decontamination evaluation (part 2). Therefore, scattering prevention and decontamination / protection of radioactively contaminated soil according to the present invention are not limited to the soil surface, and as long as the surface properties are allowed, the prevention of re-scattering of radioactive materials on the surface of any material It can also be applied to decontamination / protection.

(Neutron shielding measurement)
Next, the “transcendent solution (200B) + 3N tungsten (3.5 μm powder)” solution used in Example 5 above was applied to kraft paper, and the applied kraft paper was cut into 22 cm × 22 cm sample A (hereinafter “transcendence”). Also referred to as “shielding paper A”. Specifically, 750 g of 3N tungsten (3.5 μm powder) is mixed with 500 g of the translucent agent (200B), and this is applied to kraft paper having a thickness of 95.3 μm and a weight of 70 g / m ² . The coated kraft paper was cut into 22 cm × 22 cm to obtain Sample A.

On the other hand, 10% weight boric acid powder (Kenei Pharmaceutical Co., Ltd. Nippon Pharmacy) of the above-mentioned transcendental solution (200B) was added to the “transcendental solution (200B) + 3N tungsten (3.5 μm powder)” solution used in Example 5 above. Sample B (hereinafter referred to as “Transcendental Shielding Paper B”) mixed with boric acid ((H3BO3) 99.5% or more), this liquid agent was applied to the same kraft paper, and the applied kraft paper was cut into 22 cm × 22 cm. (Also called). Specifically, 750 g of 3N tungsten (3.5 μm powder) is mixed with 500 g of the translucent agent (200B), and 70 g of boric acid powder (Japanese Pharmacopoeia Boric Acid (Kenei Pharmaceutical Co., Ltd.) (H3BO3) 99.5% or more) is mixed, and this solution is applied to the same kraft paper, which is applied to kraft paper having a thickness of 95.3 μm and a weight of 70 g / m ² , and then the applied kraft paper. The paper was cut into 22 cm × 22 cm to obtain Sample B.

Furthermore, in order to make a comparison with the tungsten plate material, a tungsten plate having a thickness of 1 mm × 26.5 cm × 33.5 cm and a weight of 1759 g was prepared. For the sample A (“transcendent shielding paper A”), 22 cm × 22 cm and a weight of 970 g are measured, and for the sample B (“transcendental shielding paper B”), 22 cm × 22 cm and a weight of 1040 g are measured. The neutron beam shielding rate was measured.

Measurements were taken at the Tokyo Metropolitan Industrial Technology Research Center (2-4-10 Aomi, Koto-ku, Tokyo; Chairman Masatoshi Kataoka), and the source was caliphonium 252 (Cf-252) neutron from Eckert & Ziegler. A radiation source (trade name: N-252 SN; CA406S102S) (3.7 MBq as of March 1, 2011) is used as a measuring instrument, and a neutron survey meter (trade name: TPS-451BS SN; 46R928 manufactured by Aloka). )It was used.
The measurement method is a height of 1 m from the floor, the distance from the source to the measurement center of the detector is 25 cm, and there is a case where there is no sample in between, and the dose rate is shielded from the average value measured 10 times each. The rate was determined.

The tungsten plate had a thickness of 1 mm, 26.5 cm × 33.5 cm, and a weight of 1759 g. However, considering the diffraction of neutrons, the weight of the measurement sample was 22 cm × 22 cm (970 g). In order to calculate and compare the neutron beam shielding rate with this 1 mm thick tungsten plate, as a measurement sample for the transcendental shielding paper A, a weight (970 g) equivalent to a 22 mm × 22 cm 1 mm thick tungsten plate A measurement sample was obtained by stacking 17 sheets so as to be bundled.
Similarly, as for the above transcendental shielding paper B, 17 sheets of the same sheet were stacked and bundled, and the weight thereof was 1040 g.
As a result, the dose rate and shielding rate for the neutron source are as follows.

However, the dose rate when there was no sample was 27.4 ± 0.4 μSv / hour, and the shielding rate was obtained by (1−with sample / without sample) × 100.

From Table 17 above, the dose rate of the neutron source with a 1 mm thick tungsten plate is 27.0 ± 0.5 (μSv / hr), and the shielding rate is 1.5%, whereas the transcendent shielding paper In A, the dose rate is 25.9 ± 0.5 (μSv / hour) and the shielding rate is 5.5%. In the transcendent shielding paper B, the dose rate is 25.04 ± 0.4 (μSv / hour) and the shielding rate is 7.%. 3% was obtained.

This is thought to be due to the following reasons. That is, the measurement sample A is obtained by coating and impregnating a fiber material such as paper with a solution in which tungsten powder is added while stirring and adding a catalyst to an alkoxysilane solution of an organosiliconized material evolved by using a sol-gel method. In (Transcendental shielding paper A), the contained component alkoxysilane reacts with the moisture in the paper or in the air to initiate polycondensation reaction to silicon, and the contained component silicic acid is a glassy basic skeleton. In contrast, a siloxane bond occurs. Here, the vitreous liquid is soaked into the surface of the fine powder of tungsten existing between each fiber of paper or the like by capillarity, the gap, and every corner of the paper fiber to be polymerized. It becomes.

Furthermore, there will be a network of siloxane bonds that reacts with OH groups and binds firmly and does not peel off. In addition, the silane-based thin film containing tungsten fine powder and the paper fiber are formed integrally between the paper fibers, and the silane-based liquid also contains organic matter, so the bonded surface layer is moderately flexible. It has mechanical properties that have both properties and water repellency.

The measurement sample B (transcendent shielding paper B) is prepared by adding fine powder of boric acid to a solution obtained by adding a catalyst to an alkoxysilane solution to the tungsten fine powder, and stirring the resulting powder into a fiber material such as paper. It is coated and impregnated.
When radiation such as α-rays, β-rays, γ-rays, and X-rays passes through a substance, the energy it holds is given to the substance, causing interactions at the atomic level such as ionization and excitation, According to the transcendent shielding paper A and transcendental shielding paper B, detailed knowledge is not clear, but the silane compound and glass in the coated and impregnated fiber are not clear. Since fine tungsten powder is present in multiple layers in a multifaceted and superposed manner, the fine tungsten powder causes reflection, absorption, scattering, re-radiation, etc. of invading neutrons, which has a shielding effect. It is speculated that it is caused.

Such shielding effects against neutron beams have the potential to change to shields that could only be shielded with water tanks, thick concrete, lead plates, etc., and are extremely easy to process, There is no concern about environmental problems, and by using fine powders such as tungsten, it is possible to provide an inexpensive, lightweight, radiation shielding effect material with an environmentally friendly paper or fiber overlay.

Claims (13)

1. A silane-based curing / solidifying agent that hardens and solidifies the radioactively contaminated soil surface, comprising the main component compound represented by Chemical Formula 1 and a catalyst for curing and solidifying the radioactively contaminated soil surface. Solidifying agent.
   

   

   
   (In Chemical Formula 1, R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, each being hydrogen or an alkyl group having 1 to 4 carbon atoms, and n is 2 to 10)
2. The curing / solidifying agent according to claim 1, wherein the catalyst is a hydrolyzable organometallic compound.
3. The curing / solidifying agent according to claim 2, wherein the hydrolyzable organometallic compound is one or more organometallic compounds selected from the group consisting of titanium, zirconium, aluminum and tin.
4. 4. The curing or curing process according to claim 1, further comprising a compound represented by Chemical Formula 2 having three hydrolyzable substituents and one having a non-hydrolyzable substituent. Solidifying agent.
   

   

   (In Chemical Formula 2, R ₅ , R ₆ and R 7 may be the same or different, and are hydrogen, an alkyl group or an alkenyl group, and the bond between R ₅ O, R ₆₀ and R ₇ O and Si is It consists of a siloxane bond, and R ₈ is an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group (an epoxy group, a glycidyl group or an amino group) as a substituent.
5. 5. The curing / solidification according to claim 1, further comprising a compound represented by Chemical formula 3 having two hydrolyzable substituents and two hydrolyzable substituents. Agent.
   

   

   (In Chemical Formula 3, R ₉ and R ₁₁ may be the same or different, and are hydrogen, an alkyl group or an alkenyl group, and the bond between R ₉ O and R ₁₁ O and Si is a siloxane bond; ₁₀ and R ₁₂ are an alkyl group, an alkenyl group or a phenyl group which may contain an epoxy group or a glycidyl group as a substituent.
6. The curing / solidifying agent according to any one of claims 1 to 5, further comprising isopropyl alcohol (IPA), an acrylic (methacrylic acid) ester copolymer, and lead suboxide or lead monoxide.
7. A method for preventing and decontaminating radioactive substances on the soil surface contaminated with radiation by spraying the curing / solidifying agent according to any one of claims 1 to 6 on the surface of the radioactively contaminated soil.
8. A radiation protection material obtained by immersing and drying the curing / solidifying agent according to any one of claims 1 to 6 in Japanese paper or a fiber material.
9. A radiation protection method using the radiation protection material according to claim 8.
10. A radiation shielding agent comprising the curing / solidifying agent according to any one of claims 1 to 6, isopropyl alcohol (IPA), an acrylic (methacrylic) ester copolymer, and tungsten or molybdenum.
11. A radiation shielding material obtained by applying or impregnating the radiation shielding agent of claim 10 onto the surface of a paper material, a fiber material or a solid material.
12. A neutron beam shielding agent obtained by mixing the curing / solidifying agent according to any one of claims 1 to 6, isopropyl alcohol (IPA), an acrylic (methacrylic) ester copolymer, and fine powder tungsten.
13. A neutron beam shielding material obtained by applying or impregnating the surface of a paper material, a fiber material, or a solid material with the neutron beam shielding agent according to claim 12.
    

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