JP2014044197A - Paint film containing radiation shield material, and film formed body forming the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shield both an electromagnetic wave type radioactive ray and a neutron ray, and to be applicable to a wide range of subjects to be shielded.SOLUTION: A film formed body 3 is composed of a paint film 1 containing radiation shield materials, and the paint film 1 is constituted by laminating a first paint film 10 composed of a neutron ray shielding paint containing boron or boron-containing compound 11 and one or more vehicles selected from among urethane resin-based, acrylic resin-based, silicone resin-based, vinyl acetate resin-based, epoxy resin-based, phthalic acid resin-based or chloride rubber-based vehicles, and a second paint film 20 composed of X-ray and γ-ray shielding paint containing one or more metals, metallic compounds or barium-containing compounds 21 selected from among iron, tungsten, iron-containing compounds and tungsten-containing compounds, and the one or more vehicles.

Description

  The present invention relates to a radiation shielding material-containing coating film and a film forming body formed by forming the coating film.

α-rays, β-rays, γ-rays, X-rays, and neutron rays are well-known radiations. Α-rays in the form of charged particles are a paper-like material, β-rays in the same form are thin metal materials such as aluminum foil, and electromagnetic radiation such as X-rays and γ-rays is high density such as tungsten, lead, iron, etc. It is known that each can be shielded with a thick plate material. On the other hand, neutrons are excellent in their ability to travel through substances because they are electrically neutral, but are effectively shielded by materials containing hydrogen, boron, gadolinium, etc. be able to. Considering the characteristics of such various radiations, conventionally, metals such as hard and heavy lead, tungsten and iron are mainly used to shield γ rays and X rays. Also, for shielding neutrons, aqueous solutions and materials containing boric acid or borate are mainly used. For example, a radiation shielding material is known in which a hollow metal casing is filled with a fluid containing a boron-containing material and a metal oxide mixed therein to be solidified. This shielding material uses Na ₂ B ₄ O ₇ , B ₂ O ₃ , PbO, Fe ₂ O _3, etc., and mainly shields the neutron beam by boron or hydrogen, and γ by the casing and the metal therein. The line can be shielded (see, for example, Patent Document 1).

  Also, a thermosetting resin excellent in shielding neutron rays and a high density inorganic substance such as lead oxide and tungsten oxide excellent in shielding γ rays and X rays are mixed and cured to a density of 2.0 or more. Thus, there is also known a method of obtaining a molded product that has a high hydrogen atom density and can effectively shield γ rays, X rays, and neutron rays simultaneously with high density (see, for example, Patent Document 2). . Each shielding performance is improved by adding a hydrogen storage alloy to these raw materials, further enhancing the neutron beam shielding performance and increasing the density of the molded product.

  Furthermore, gadolinium with a large thermal neutron capture cross section, its oxides, nitrides, borides, carbides, oxynitrides, oxyborides, carbonates, nitroborides, carbonitrides, carbonitrides, carbonitrides, There is also known a radiation shielding material which contains at least one kind of oxyboronitride, oxyboronitride carbide, or a composite or mixture thereof, and tungsten, and contains a binder such as iron and is sintered. (For example, see Patent Document 3).

  In view of the harmful effects of lead, a high-density tungsten-containing sheet is also known and commercialized, which is a composite material in which tungsten and its alloy powder and elastomer are heated and kneaded as an alternative to lead. Has been. Further, a radiation shielding sheet obtained by dispersing a high-density zeolite-containing fiber obtained by crystallizing zeolite with high density inside cellulose fibers in a thermoplastic elastomer and forming a sheet has been commercialized. Further, a silicone rubber-based neutron beam shielding material in which gadolinium oxide powder or boron carbide is added to silicone rubber, a polyethylene-based neutron radiation shielding material in which 10% by weight of boron oxide is added to high-density polyethylene resin or silicone rubber, or a silicone rubber-based γ. Wire shielding materials have also been commercialized.

JP 05-142392 A Japanese Patent Laid-Open No. 06-180389 JP 2008-008656 A

  However, the above-described conventionally known shielding materials and shielding methods have the following problems. The material disclosed in Patent Documents 1 to 3, that is, a molded body in which a shielding material for each type of radiation is mixed to simultaneously shield a plurality of types of radiation, can surely shield a plurality of types of radiation at the same time. Have However, once such a molded body is manufactured, it is difficult to shield it in a flexible manner corresponding to the type and dose of radiation. Tungsten-containing fibers and compacts are effective for shielding electromagnetic X-rays and γ rays, but are not suitable for shielding neutron rays. In addition, even if a molded product, fiber, or sheet in which a substance that shields radiation is dispersed is manufactured, it can only be used for specific purposes, and objects having various forms such as houses, containers, and containers can be protected from radiation. It is not suitable for shielding or preventing leakage of radiation from such objects.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a shielding material that can simultaneously shield electromagnetic radiation and neutron rays and can be applied to a wide range of shielding objects.

The radiation shielding material-containing coating film according to one embodiment of the present invention for achieving the above-described object is
Contains boron or a boron-containing compound and one or more color developing agents selected from urethane resin, acrylic resin, silicone resin, vinyl acetate resin, epoxy resin, phthalic acid resin or chlorinated rubber A first coating formed from a neutron shielding coating;
It is formed from an X-ray / γ-ray shielding coating material containing one or more metals selected from iron, tungsten, iron-containing compounds and tungsten-containing compounds, or a barium-containing compound and the one or more color formers. A second coating film;
Are laminated.

  The radiation shielding material-containing coating film according to another aspect of the present invention further includes at least one of natural fiber, synthetic fiber, glass wool, carbon fiber, metal fiber, and metal net in the first coating film and / or the second coating film. The reinforcing material which consists of any one is provided.

  The radiation shielding material containing coating film which concerns on another form of this invention is further equipped with one reinforcing material for every 100-1000 micrometers of film thicknesses of a 1st coating film and / or a 2nd coating film.

  A film-forming body according to an aspect of the present invention is formed by forming any of the above-described coating films containing a radiation shielding material on a front side surface and / or a back side surface of a coating target represented by a sheet, a container, or a building. It becomes.

  In the film forming body according to another aspect of the present invention, the coating target is a container for nuclear waste.

  According to the present invention, electromagnetic radiation and neutron radiation can be simultaneously shielded and can be applied to a wide range of shielding objects.

FIG. 1: shows the longitudinal cross-sectional view of the film formation body which concerns on 1st embodiment of this invention, and each expanded sectional view of the part A and its further part B. FIG. FIG. 2: shows the longitudinal cross-sectional view of the film formation body which concerns on 2nd embodiment of this invention, and each expanded sectional view of the part A and its further part B. FIG. FIG. 3 shows a plan view and a side view of the reinforcing member shown in FIG.

  Next, preferred embodiments of the radiation shielding material-containing coating film according to the present invention and a film forming body formed by forming the coating film will be described. However, the radiation shielding material-containing coating film will be described in the embodiment of the film forming body.

<First embodiment>
FIG. 1: shows the longitudinal cross-sectional view of the film formation body which concerns on 1st embodiment of this invention, and each expanded sectional view of the part A and its further part B. FIG.

  The radiation shielding material-containing coating film 1 according to the first embodiment is formed on the front surface 2 a of the coating object 2. The radiation shielding material-containing coating film 1 and the coating object 2 constitute a film forming body 3. The radiation shielding material-containing coating film 1 is formed by laminating a first coating film 10 and a second coating film 20. The first coating film 10 is boron or a boron-containing compound 11; and one or more selected from urethane resin, acrylic resin, silicone resin, vinyl acetate resin, epoxy resin, phthalic resin, or chlorinated rubber A neutron beam shielding paint containing: The second coating film 20 is an X-ray film containing one or more metals or metal compounds or barium-containing compounds 21 selected from iron, tungsten, iron-containing compounds and tungsten-containing compounds, and the one or more color developing agents. It is formed from a gamma ray shielding coating. Either the first coating film 10 or the second coating film 20 may be a front layer. Hereinafter, the paint, the coating film, and the coating object 2 for forming the first coating film 10 and the second coating film 20 will be described in more detail.

I. Paint 1. Neutron Ray Shielding Paint (1) Neutron Ray Shielding Material The neutron ray shielding material contained in the neutron ray shielding paint for forming the first coating film 10 is made of boron or a boron-containing compound 11. Boron-containing compounds include boron oxides as well as boron oxides, carbides, nitrides, oxynitrides, carbonates, carbonitrides. Boron or the boron-containing compound 11 is preferably contained in the neutron beam shielding paint at a ratio of 2 to 70 parts by mass with respect to 100 parts by mass of the neutron beam shielding coating material. Boron or the boron-containing compound 11 may have any form of granular, acicular, fibrous, or plate-like.

(2) Color extender The color extender contained in the neutron beam shielding paint is selected from urethane resin, acrylic resin, silicone resin, vinyl acetate resin, epoxy resin, phthalate resin or chlorinated rubber. It is a liquid resin containing one or two or more synthetic resins. The color developing agent may be either water-based or organic solvent-based resin, and is preferably in the form of an emulsion in which fine particles of the above synthetic resin are hydrophilized with an emulsifier typified by a surfactant and dispersed in water. The color developing agent is preferably contained in the neutron beam shielding paint at a ratio of 98 to 30 parts by mass with respect to 100 parts by mass of the neutron beam shielding paint.

  Here, the urethane resin dispersed in the color developing agent dispersion is a polymer obtained by copolymerizing monomers with a urethane bond formed by condensation of a compound having an isocyanate group and a hydroxyl group. Similarly, the acrylic resin is a polymer obtained by polymerizing an acrylic ester or a methacrylic ester. The silicone resin is a polymer in which the main skeleton of the molecular structure is a siloxane bond (O—Si—O), and a hydrocarbon group such as an alkyl group is bonded to Si. Vinyl acetate resin is a polymer obtained by radical polymerization of vinyl acetate. Epoxy resin is a polymer that has been cross-linked by the epoxy groups remaining in the polymer. Most commonly, a copolymer of bisphenol A and epichlorohydrin is cured using polyamine or acid anhydride as a curing agent. Obtained. The phthalic acid resin is a resin obtained by polymerizing phthalic acid as a monomer. Chlorinated rubber is chlorinated natural rubber or synthetic rubber.

(3) Others The neutron beam shielding paint may contain a filler in addition to the above-described neutron beam shielding material and color developer.

2. X-ray / γ-ray shielding paint (1) X-ray / γ-ray shielding material The X-ray / γ-ray shielding material contained in the X-ray / γ-ray shielding paint for forming the second coating film 20 is iron, It consists of one or more metals or metal compounds selected from tungsten, iron-containing compounds and tungsten-containing compounds or barium-containing compounds 21. The iron-containing compound or the tungsten-containing compound may be, for example, an iron or tungsten oxide, nitride, carbide, oxynitride, carbonate, carbonitride, carbonitride, alloy with another metal, or a composite thereof. It is a mixture. Examples of the barium-containing compound include one or more of barium sulfate, barium nitrate, barium chloride, barium oxide, barium iodide, barium carbonate, and the like. The metal or metal compound or barium-containing compound 21 is preferably contained in the X-ray / γ-ray shielding coating material in a ratio of 3 to 70 parts by mass with respect to 100 parts by mass of the X-ray / γ-ray shielding coating material. The metal, metal compound, or barium-containing compound 21 may have any form of granular, acicular, fibrous, or plate-like.

(2) Color developing agent As the color developing agent, the same type as the color developing agent contained in the neutron ray shielding coating described above can be used. The color developing agent is preferably contained in the X-ray / γ-ray shielding coating material in a ratio of 97 to 30 parts by mass with respect to 100 parts by mass of the X-ray / γ-ray shielding coating material.

(3) Others The X-ray / γ-ray shielding coating material may contain a filler in addition to the above-mentioned X-ray / γ-ray shielding material and color developer.

II. Coating 1. First Coating Film The first coating film 10 is formed from the above-described neutron beam shielding coating. The thickness of the first coating film 10 can be increased or decreased according to the intensity of the neutron beam.

2. Second coating film The second coating film 20 is formed from the aforementioned X-ray / γ-ray shielding coating. The thickness of the second coating film 10 can be adjusted up or down depending on the intensity of X-rays and γ-rays.

III. Coating target As the coating target 2, a sheet, a container, or a building can be exemplified, and as a container, a nuclear waste container can be more preferably exemplified. When the radiation shielding material-containing coating film 1 is formed on a nuclear waste container, it is formed only on the front surface 2a as shown in FIG. 1, and only the back surface 2b or both front and back surfaces 2a, 2b. It can also be formed.

<Second Embodiment>
FIG. 2: shows the longitudinal cross-sectional view of the film formation body which concerns on 2nd embodiment of this invention, and each expanded sectional view of the part A and its further part B. FIG. FIG. 3 shows a plan view and a side view of the reinforcing member shown in FIG.

  The radiation shielding material-containing coating film 1 according to the second embodiment is formed on the front surface 2 a of the coating object 2. The radiation shielding material-containing coating film 1 according to the second embodiment is different from the radiation shielding material-containing coating film 1 according to the first embodiment, and the reinforcing material 30 as shown in FIG. Is provided. The reinforcing member 30 preferably has a flat plate shape, but it does not matter whether it has a flat plate shape or not. The reinforcing material 30 is preferably made of at least one of natural fiber, synthetic fiber, glass wool, carbon fiber, metal fiber, and metal net. Although only one reinforcing material 30 may be provided in the second coating film 20, a plurality of reinforcing materials 30 may be provided. Moreover, it is preferable to provide the reinforcing material 30 for every 100-1000 micrometers in the film thickness in the 2nd coating film 20. As shown in FIG.

  The reinforcing material 30 can be provided only in the first coating film 10 or in both the first coating film 10 and the second coating film 20. Even when the reinforcing material 30 is provided in the first coating film 10, only one reinforcing material 30 may be provided in the first coating film 10, but a plurality of reinforcing materials 30 may be provided. Moreover, it is preferable to provide the reinforcing material 30 in the 1st coating film 10 for every 100-1000 micrometers in the film thickness. When the reinforcing material 30 is provided in the first coating film 10 and / or the second coating film 20, the film can be reinforced and can be prevented from being easily peeled off.

  As described above, when the radiation shielding material-containing coating film 1 according to each embodiment is formed on the surface of the coating object 2, it is inexpensive and easy to handle, corresponding to the line type and dose from the high level to the low level. In addition, excellent radiation shielding performance can be exhibited. In addition, when the radioactive material released in large quantities in nature is decontaminated or shielded from the radioactive material released after concentration, the coating film 1 is formed on the container / material for transportation / storage. Radiation shielding performance can be exhibited efficiently and economically.

  The present invention can be used to shield external radiation or internal radiation.

1 Radiation shielding material-containing coating film 2 Coating target (for example, sheet, container, building, or nuclear waste container)
2a Front side surface 2b Back side surface 3 Film forming body 10 First coating film 11 Boron or boron-containing compound 20 Second coating film 21 Metal or metal compound or barium-containing compound 30 Reinforcing material

Claims (5)

Contains boron or a boron-containing compound and one or more color developing agents selected from urethane resin, acrylic resin, silicone resin, vinyl acetate resin, epoxy resin, phthalic acid resin or chlorinated rubber A first coating formed from a neutron beam shielding coating;
It is formed from an X-ray / γ-ray shielding coating material containing one or more metals selected from iron, tungsten, iron-containing compounds and tungsten-containing compounds, or a barium-containing compound and the one or more color formers. A second coating film,
A radiation shielding material-containing coating film formed by laminating layers.   The first coating film and / or the second coating film includes a reinforcing material made of at least one of natural fiber, synthetic fiber, glass wool, carbon fiber, metal fiber, and metal net. Item 2. The radiation shielding material-containing coating film according to Item 1.   The said reinforcing material is provided with the said 1st coating film and / or the said 2nd coating film for every 100-1000 micrometers of film thickness, The radiation shielding material containing coating film of Claim 2 characterized by the above-mentioned.   The radiation shielding material-containing coating film according to any one of claims 1 to 3 is formed on a front side surface and / or a back side surface of a coating target represented by a sheet, a container, or a building. Film forming body.   The film forming body according to claim 4, wherein the coating target is a nuclear waste container.

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