TW201515009A - Radioactivity protective sheet and method for manufacturing radioactivity protective sheet - Google Patents

Abstract

The purpose of the present invention is to provide a radioactivity protective sheet and a method for manufacturing the same which can easily protect a human body or a product from radioactivity and can shield radioactivity in daily lives. The radioactivity protective sheet of the present invention includes a radioactivity shielding layer containing chloro-sulfonation polyethylene and a radioactivity shielding particle. The radioactivity shielding particle includes (a) tungsten or tungsten compounds, and/or (b) barium or barium compounds. It is ok, if the radioactivity protective sheet is a laminated body having multiple radioactivity shielding layers. The radioactivity protective sheet comprises a radioactivity shielding layer including (a) tungsten or tungsten compounds, and a radioactivity shielding layer including (b) barium or barium compounds as the radioactivity shielding particle.

Description

Radioactive protective sheet and method for producing radioactive protective sheet

The present invention relates to a radioactive protective sheet and a method of manufacturing the same.

As a garment that takes into consideration the adverse effects of radioactive substances on the human body, it has (A) radioactive protective clothing for preventing radioactive substances such as radioactive dust from adhering to the human body and (B) radiation protective clothing for masking radioactive materials to emit radiation.

In the above-mentioned radioactive protective clothing (the aforementioned A), even if the radioactive dust floats in the air, the radioactive dust can be attached to the protective clothing without adhering to the human body, and then can be prevented by cleaning the radioactive dust attached to the protective clothing. Radioactive dust has an adverse effect on the human body. However, the radioactive protective suit does not cover the radiation itself, and the wearer is exposed to radiation even when wearing the radioactive protective suit.

On the other hand, in the case where the radiation protective clothing (the aforementioned B) is operated in a nuclear power plant, for example, it is used to prevent the operator from being exposed. As the radiation protective suit, in order to shield the radiation, a lead-containing layer is generally provided. However, lead is hazardous to health, and must be discarded when obsolete radiation protective clothing is discarded. Be careful.

Further, as the radiation protective garment (the aforementioned B), there has been reported a product having a polymer layer in which a material that does not transmit radiation is mixed with a polymer such as polyurethane (Japanese Patent Publication No. 2008-538136). In this publication, as a material that does not transmit radiation, in addition to lead, barium sulfate, tungsten, and the like are listed. However, in order to produce a high radiation mask effect, the radiation protective clothing described in this publication must contain a large amount of radiopaque material, and as a result, the protective clothing is very heavy and expensive.

Recently, in addition to special places such as nuclear power plants, that is, even in places where daily life is concerned, people who consider protection against radiation exposure are gradually increasing. However, radiation exposure cannot be avoided even if wearing a radioactive protective suit (A). Further, since the aforementioned radiation protective clothing (the aforementioned B) is very heavy and expensive, it is difficult to achieve wearing in daily life.

[Previous Technical Literature] [Patent Document]

Patent Document 1: Special Table 2008-538136

Therefore, in view of the above circumstances, the present invention has an object of providing a radioactive protective sheet which can be easily and surely shielded from radiation and which can be easily used in daily life, and a method for producing the same.

The invention obtained to solve the above problems is a radioactive protective sheet comprising a radiation mask layer containing chlorosulfonated polyethylene and radiation mask particles, wherein the radiation mask particles are (a) tungsten or A tungsten compound and/or (b) a ruthenium or osmium compound.

Since the radioactive protective sheet is provided with a radiation mask layer containing chlorosulfonated polyethylene and radiation mask particles, the radiation can be masked by the aforementioned radiation mask layer. In particular, in the radioactive protective sheet, since the adhesive of the radiation mask layer contains chlorosulfonated polyethylene as a main component, not only radiation is masked by the radiation mask particles, but also the adhesive can mask the radiation. Therefore, the use of the radioactive protective sheet, for example, in the form of a radioactive protective suit, can have a positive radiation masking effect as compared with current radioactive protective garments. Further, since the radioactive protective sheet contains chlorosulfonated polyethylene, it has excellent weather resistance, ozone resistance, chemical resistance, and the like. Therefore, the radioactive protective sheet can be applied to articles that are used outdoors for a long period of time and the like. Further, the chlorosulfonated polyethylene has excellent color stability, and exhibits rubbery elasticity at room temperature, so that it can be easily processed into a clothing such as a radioactive protective garment, and has a good wearing feeling when wearing the above-mentioned clothing. Further, in the radioactive protective sheet, as the radiation masking particles, (a) tungsten or a tungsten compound and/or (b) a ruthenium or osmium compound is used, and since the lead is discarded, when the expired radioactive protective sheet is discarded, It is not cumbersome in terms of treatment methods and measures to prevent environmental pollution.

The radiation mask particles of the radioactive protective sheet preferably contain barium sulfate. As described above, since barium sulfate is used as the radiation masking particles, the radiation can be surely masked by the radiation mask particles which are relatively easily obtained.

The radioactive protective sheet may be provided with a plurality of layers of the aforementioned radiation mask layer. Therefore, for example, the coating amount of the coater used in the production of the radioactive protective sheet has a certain limit, and even if the target film thickness is not obtained in one application, the target film thickness can be achieved by laminating a plurality of layers of the radiation mask layer.

In the radioactive protection sheet, the radiation mask layer may include a radiation mask layer containing (a) a tungsten or tungsten compound and a radiation mask layer containing (b) a ruthenium or osmium compound. Therefore, the radioactive protective sheet can select the color of the outer surface while maintaining the radiation masking effect. Specifically, since the aforementioned (a) tungsten or tungsten compound mainly exhibits black color, and the above (b) ruthenium or osmium compound mainly exhibits white color or colorless color, the color of the outer surface can be appropriately selected. For example, when the radioactive protective sheet is used for an article in which the stain is not conspicuous, the outer surface may be provided with a radiation mask layer containing (a) a tungsten or tungsten compound, and when used for a bright color, The outer surface may be provided with a radiation mask layer containing (b) a ruthenium or osmium compound. Further, a radiation mask layer containing (b) a ruthenium or osmium compound may be disposed on the outer surface of the radioactive protection sheet, and a pigment such as red or blue other than the above (b) bismuth or bismuth compound may be added, or A printed pattern or the like on the outer surface side of the second radiation mask layer imparts creativity to the radioactive protective sheet. As mentioned above, due to The radioactive protective sheet is creative, and each radioactive protective sheet can be distinguished according to the difference in appearance. That is, for example, it may be set such that the content of the radiation mask particles or the size of the radioactive protection sheet (the size of the coverage surface formed by the radioactive protection sheet) or the like is distinguished according to the color.

In the radioactive protective sheet, as the radiation mask layer, in the case of providing a radiation mask layer containing (a) a tungsten or tungsten compound and (b) a ruthenium or osmium compound, the above (b) ruthenium or osmium compound The ratio of the average particle diameter to the average particle diameter of the above (a) tungsten or tungsten compound may be 0.01 or more and 0.1 or less. Therefore, the (b) ruthenium or osmium compound having a small average particle diameter enters a gap between the (a) tungsten or tungsten compound having a large average particle diameter, and the density of the radiation mask particles in the radioactive protective sheet can be increased. The radiation masking effect of the radioactive protective sheet can be improved.

In the radioactive protective sheet, the ratio of the (b) lanthanum or cerium compound to the (a) tungsten or tungsten compound is preferably 5% by mass or more and 50% by mass or less. Therefore, (b) the ruthenium or osmium compound can sufficiently enter (a) a gap between the tungsten or tungsten compound to each other, and the density of the radiation mask particles in the radioactive protective sheet can be increased. As a result, the radiation masking effect of the radioactive protective sheet can be further improved.

The proportion of the radiation mask particles in the radiation mask layer is preferably 30% by mass or more and 85% by mass or less. Therefore, the radioactive protective sheet can be given a radiation mask that can effectively protect the radiation level of the wearer or the like. The effect, in addition, can be manufactured relatively easily.

Further, the area density of the radiation mask particles in the radiation mask layer is preferably 0.1 g/cm 2 or more and 1 g/cm 2 or less. Therefore, it is suitable to impart a radiation masking effect to the radioprotective sheet which can effectively protect the radiation level by the wearer or the like.

The radioactive protective sheet may further comprise a substrate layer. Therefore, the strength of the radioactive protective sheet can be improved.

The radioactive protective sheet may also have an antifouling layer on the outermost layer. Therefore, it is possible to make stains such as radioactive substances difficult to adhere to the outer surface of the radioactive protective sheet. As a result, it is possible to more effectively protect the wearer and the like from contacting the radioactivity, and it is also difficult to attach the radioactive substance to the radioactive protective sheet. Further, the attached radioactive substance can be easily removed.

The antifouling layer may be a resin layer made of an olefin resin as a main component. The olefin resin layer has a high surface tension and exhibits excellent antifouling properties.

Further, another invention for solving the above problems is a method for producing a radioactive protective sheet, wherein the above manufacturing method has a material preparation step of using (a) a tungsten or tungsten compound as a radiation masking particle and/or a solvent. (b) a ruthenium or osmium compound is dispersed in a binder containing chlorosulfonated polyethylene as a main component to prepare a radiation mask layer forming material; In the step of forming, the aforementioned radiation mask layer forming material is formed into a sheet body.

According to the above production method, a radioactive protective sheet comprising a radiation mask layer containing chlorosulfonated polyethylene and the aforementioned radiation mask particles can be obtained. Therefore, the aforementioned radioactive protective sheet can easily protect the radiation and radiation in a daily life by a wearer or the like as described above.

Here, "radioactive" refers to the ability to emit radiation when an unstable atomic nucleus is converted into a stable nucleus. In addition, "radiation" means electromagnetic waves such as X-rays and gamma rays emitted from the above-mentioned radioactive (radioactive substance), and particle beams such as rays, rays, and neutron rays. Further, the "average particle diameter" means a volume average particle diameter, which is measured by a dynamic light scattering measurement at 23 ° C. Specifically, a submicron particle size analyzer ("NICOMPMODEL370" manufactured by Nozaki Industries Co., Ltd.) is used as the measurement device, and 0.1% by mass to 2.0% by mass of the radiation mask particles are dispersed in tetrahydrofuran. Radiation mask particle dispersion. Further, "area density" means the ratio (mass) of the presence of the radiation mask particles per unit area (1 cm 2 ) in the plane direction of the radioactive protection sheet.

As described above, the present invention can cover radiation easily and surely, and further provides a radioactive protective sheet which can be easily used in daily life and a method for producing the same.

1‧‧‧ Radioactive protective sheet

2‧‧‧radiation mask

3‧‧‧Antifouling layer

11‧‧‧ Radioactive protective sheet

12‧‧‧First Radiation Mask

13‧‧‧Second Radiation Mask

21‧‧‧ Radioactive protective sheet

22‧‧‧Substrate layer

31‧‧‧ Radioactive protective sheet

41‧‧‧ Radioactive protective sheet

51‧‧‧ Radioactive protective sheet

61‧‧‧ Radioactive protective sheet

71‧‧‧ Radioactive protective sheet

Fig. 1 is a schematic cross-sectional view showing a radioactive protective sheet in one embodiment of the present invention.

2 is a schematic cross-sectional view of a radioactive protective sheet in an embodiment different from the radioactive protective sheet of FIG. 1.

3 is a schematic cross-sectional view of a radioactive protective sheet in an embodiment different from the radioactive protective sheets of FIGS. 1 and 2.

Fig. 4 is a schematic cross-sectional view showing a radioactive protective sheet in a different embodiment from the radioactive protective sheet of Figs. 1 to 3.

Fig. 5 is a schematic cross-sectional view showing a radioactive protective sheet in a different embodiment from the radioactive protective sheet of Figs. 1 to 4.

Fig. 6 is a schematic cross-sectional view showing a radioactive protective sheet in a different embodiment from the radioactive protective sheet of Figs. 1 to 5.

Fig. 7 is a schematic cross-sectional view showing a radioactive protective sheet in a different embodiment from the radioactive protective sheet of Figs. 1 to 6.

Fig. 8 is a schematic cross-sectional view showing a radioactive protective sheet in a different embodiment from the radioactive protective sheet of Figs. 1 to 7.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

(radioactive protective sheet 1)

The radioactive protective sheet 1 of Fig. 1 is composed of a sheet-like, elastic radiation mask layer containing chlorosulfonated polyethylene and radiation masking particles. As before Radiation mask particles comprising (a) a tungsten or tungsten compound and (b) a ruthenium or osmium compound.

The chlorosulfonated polyethylene is a substance which imparts crystallinity by introducing chlorine into a polyethylene having crystallinity and imparts rubber elasticity. Since the chlorosulfonated polyethylene does not contain a double bond in the main chain, it is excellent in weather resistance, ozone resistance, heat resistance, flame retardancy, and the like, and a halogen mask is also expected to have a radiation mask effect. Since the radioactive protective sheet 1 contains the chlorosulfonated polyethylene as described above as a binder and has rubber elasticity, it can be deformed according to the shape of the covering, and is easy to process, and can be suitably used as, for example, a jacket, a hat, a glove, or the like. Clothing materials. Further, since the radioactive protective sheet 1 has the above-described chlorosulfonated polyethylene, which is excellent in weather resistance, ozone resistance, heat resistance, and the like, it can be suitably used for outdoor long-term use and outdoor work.

As a method for producing the chlorosulfonated polyethylene, for example, chlorine and sulfur dioxide can be introduced into a polyethylene dissolved in a solvent, and a catalyst can be used for the reaction to be produced by chlorination or chlorosulfonation. Examples of the polyethylene as the raw material include high density polyethylene and low density polyethylene. When high-density polyethylene is used as the raw material polyethylene, chlorosulfonated polyethylene having high mechanical strength and excellent workability can be obtained, and in the case where the polyethylene is a low-density polyethylene containing a long-chain branch. Next, a chlorosulfonated polyethylene having a low viscosity of a solution dissolved in a solvent and excellent coatability can be obtained. In addition, as the chlorosulfonated polyethylene, a product manufactured by Toyo Co., Ltd. can be used. A product named "TOSO-CSM" and product number "TS-320".

In the above-mentioned (a) tungsten or tungsten compound, the tungsten compound is not particularly limited as long as it is a compound containing tungsten, and examples thereof include carbide (WC, W2C), oxide (WO, WO2, etc.), nitride, and boride. Or a composite compound with other metals such as a tungsten alloy. As the above (a) tungsten or tungsten compound, tungsten which is easily available and which is inexpensive, and a carbide thereof are preferable. Further, as the tungsten, a trade name "high-purity tungsten powder" manufactured by Nippon Tungsten Co., Ltd. can be used.

The above (a) tungsten or tungsten compound is preferably a fine powder. The upper limit of the average particle diameter of the (a) tungsten or tungsten compound is preferably 10 μm, more preferably 7 μm, and particularly preferably 5 μm. On the other hand, the lower limit of the average particle diameter is preferably 0.5 μm, more preferably 1 μm, and particularly preferably 2 μm. If the average particle diameter of the (a) tungsten or tungsten compound is greater than the above upper limit, the (a) tungsten or tungsten compound may be detached from the radioactive protective sheet; on the other hand, if the aforementioned (a) tungsten or tungsten If the average particle diameter of the compound is less than the aforementioned lower limit, then (a) the tungsten or tungsten compound may be difficult to uniformly distribute in the radiation mask layer.

In the above (b) ruthenium or osmium compound, as the ruthenium compound, barium sulfate is particularly suitable from the viewpoint of easy availability, etc., but other compounds containing ruthenium may be used, and for example, ruthenium chloride, ruthenium hydroxide or strontium titanate may be used. Wait.

The above (b) ruthenium or osmium compound is preferably a fine powder. As the aforementioned (b) The upper limit of the average particle diameter of the ruthenium or osmium compound is preferably 2.3 μm, more preferably 1.8 μm, and particularly preferably 1.5 μm. On the other hand, the lower limit of the average particle diameter is preferably 0.3 μm, more preferably 0.8 μm, and particularly preferably 1 μm. If the average particle diameter of the (b) ruthenium or osmium compound is larger than the above upper limit, (b) the ruthenium or osmium compound may not be closely embedded in (a) a gap formed between the tungsten or the tungsten compound; When the average particle diameter of the (b) ruthenium or osmium compound is less than the above lower limit, the treatment of (b) ruthenium or osmium compound may become difficult at the time of production.

Further, it is preferred that the (b) ruthenium or osmium compound has a smaller average particle diameter than the above (a) tungsten or tungsten compound. (b) The average particle diameter of the ruthenium or osmium compound is preferably 0.01 or more and 0.1 or less, more preferably 0.03 or more and 0.08 or less, and particularly preferably 0.04 or more, in comparison with the average particle diameter of the (a) tungsten or tungsten compound. And it is 0.06 or less. Since (b) the average particle diameter of the ruthenium or osmium compound is within the foregoing range with respect to (a) the average particle diameter of the tungsten or tungsten compound, the (b) ruthenium or osmium compound having a small particle can be efficiently entered into the particle ( a) A gap created by tungsten or tungsten compounds. Therefore, the density of the radiation mask particles in the radiation mask layer can be increased, and the radiation masking effect of the radioactive protection sheet 1 can be improved.

The upper limit of the ratio of the (b) ruthenium or osmium compound to the above (a) tungsten or tungsten compound is preferably 50% by mass, more preferably 43% by mass, particularly preferably 34% by mass. On the other hand, the lower limit of the ratio of the (b) ruthenium or osmium compound to the above (a) tungsten or tungsten compound is preferably 5% by mass. More preferably, it is 8 mass%, and particularly preferably 10 mass%. If (b) the ratio of the ruthenium or osmium compound to the above (a) tungsten or tungsten compound is greater than the above upper limit, then (b) the ruthenium or osmium compound is formed with respect to the gap between the (a) tungsten or tungsten compound Excessive ratio may cause the effect of (b) bismuth or bismuth compound to be weakened, and the coating liquid containing both may be easily cured, which may make coating difficult, and may further hinder the elasticity of the radioactive protective sheet 1. On the other hand, if the ratio of the (b) ruthenium or osmium compound to the (a) tungsten or tungsten compound is less than the aforementioned lower limit, the (b) ruthenium or osmium compound is mutually related to the (a) tungsten or tungsten compound. The proportion of gaps generated between them becomes less, and (b) the ruthenium or osmium compound may not be sufficiently buried in (a) the gap between the tungsten or tungsten compounds.

The radioactive protective sheet 1 may contain a substance having a radiation masking effect other than the aforementioned (a) tungsten or tungsten compound and (b) ruthenium or osmium compound. Examples of the substance as described above include a substance having an atomic number of 30 or more, and specific examples thereof include zinc, ruthenium, osmium, zirconium, hafnium, yttrium, molybdenum, niobium, tin, lead, antimony or a compound thereof. . Among them, tin, molybdenum, ruthenium, osmium, zirconium and a compound thereof are preferred from the viewpoint of availability.

The upper limit of the ratio of the aforementioned radiation mask particles in the radiation mask layer 2 is preferably 85% by mass, more preferably 80% by mass, and particularly preferably 70% by mass. On the other hand, in the radiation mask layer 2, the lower limit of the ratio of the radiation mask particles is preferably 30% by mass, more preferably 35% by mass, and particularly preferably 40% by mass. If the aforementioned radiation masking particles in the aforementioned radiation mask layer 2 When the proportion of the sub-portion is larger than the above upper limit value, the proportion of the chlorosulfonated polyethylene as the binder is relatively reduced, which may cause the strength of the radiation mask layer 2 to be lowered, and further, the coating liquid containing the radiation mask particles may be caused. Coating becomes difficult, and further, the elasticity of the radioactive protective sheet 1 may be hindered. On the other hand, if the proportion of the aforementioned radiation mask particles in the radiation mask layer 2 is less than the aforementioned lower limit value, the radiation mask effect of the radiation mask layer 2 is lowered, and the body or the like cannot be effectively shielded from radiation.

The upper limit of the area density of the aforementioned radiation mask particles in the radiation mask layer 2 is preferably 1 g/cm 2 , more preferably 0.8 g/cm 2 , and particularly preferably 0.6 g/cm 2 . On the other hand, the lower limit of the area density of the radiation mask particles in the radiation mask layer 2 is preferably 0.1 g/cm 2 , more preferably 0.3 g/cm 2 , and particularly preferably 0.4 g/cm 2 . If the density of the aforementioned radiation mask particles in the radiation mask layer 2 is greater than the aforementioned upper limit value, the radioactive protective sheet 1 may become excessively heavy; on the other hand, if the aforementioned radiation mask in the radiation mask layer 2 is When the density of the cover particles is less than the aforementioned lower limit value, the radiation mask effect of the radiation mask layer 2 is lowered, and the body or the like cannot be effectively shielded from radiation.

The upper limit of the thickness of the radiation mask layer 2 is preferably 5 mm, more preferably 3 mm. On the other hand, the lower limit of the thickness is preferably 0.2 mm, more preferably 0.5 mm. If the thickness of the radiation mask layer 2 is greater than the above upper limit value, the radioactive protective sheet 1 is too thick, which may cause deformation and processing difficulties with the shape of the covering; on the other hand, if the radiation is covered If the thickness of the cover layer 2 is less than the aforementioned lower limit value, sufficient radiation protection effect may not be obtained, and further, the strength of the radioactive protection sheet 1 may be insufficient.

The radioactive protective sheet 1 may have an antifouling layer 3 on the outermost layer. As described above, since the radioactive protective sheet 1 is provided with the antifouling layer 3 on the outermost layer, it is possible to make it difficult for the radioactive substance to adhere to the outer surface of the radioactive protective sheet 1. Therefore, while the wearer or the like is more effective in protecting radioactivity, the radioactive substance can be hardly attached to the radioactive protective sheet, and in addition, the attached radioactive substance can be easily removed. As the antifouling layer, a resin layer made mainly of an olefin resin can be suitably used. The olefin-based resin layer can improve the surface tension and exhibit excellent antifouling properties. Further, as the antifouling layer 3, for example, a film containing a photocatalytic substance, a film subjected to hydrophilic surface treatment, or a film subjected to an antistatic treatment may be used.

The film containing the photocatalytic substance can cause the dirt such as mold and bacteria adhering to the outer surface of the radioactive protective sheet 1 to be decomposed by ultraviolet rays from the outside, and the outer surface of the radioactive protective sheet 1 can be kept clean. As a result, it is possible to make it difficult for the radioactive substance to adhere to the outer surface of the radioactive protective sheet 1.

Examples of the photocatalytic substance include TiO2, ZnO, SrTiO, CdS, GaP, InP, GaAs, BaTiO3, K2NbO3, Fe2O3, Ta2O5, WO3, SnO2, Bi2O3, NiO, Cu2O, SiC, SiO2, MoS2. InPb, RuO2, CeO2, etc. Among them, titanium dioxide (TiO2), titanium peroxide (peroxytitanate), zinc oxide (ZnO), tin oxide (SnO2), barium titanate (SrTiO3), tungsten trioxide (WO3), and bismuth oxide (Bi2O3) are preferred. ), ferric oxide (Fe2O3). The particle diameter of the photocatalytic substance is preferably a small particle diameter as the particle diameter is smaller as the particle diameter is smaller. Specifically, the average particle diameter is preferably 50 nm or less, more preferably 20 nm or less.

The amount of the photocatalytic substance to be contained in the film containing the photocatalyst is preferably from the viewpoint of obtaining high photocatalytic activity, and more preferably, it is preferably 10% by mass or more and 70%. Below mass%. If the amount of the photocatalytic substance is less than 10% by mass, the photocatalytic activity may be insufficient. On the other hand, if the photocatalytic substance is used in an amount of more than 70% by mass, although the photocatalytic activity is improved, the phase may be The adhesion of the adjacent radiation mask layer is insufficient, so that the surface of the antifouling layer is insufficient in abrasion resistance and the outdoor durability is lowered.

The photocatalytic substance is preferably used by being supported on inorganic porous particles. Therefore, the aforementioned photocatalytic substance can be uniformly dispersed in the antifouling layer. Examples of the inorganic porous fine particles as described above include silicone, (synthetic) zeolite, titanium zeolite, zirconium phosphate, calcium phosphate, calcium zinc phosphate, hydrotalcite, hydroxyphosphorus lime, cerium oxide-alumina, calcium citrate, and the like. Magnesium aluminum silicate, diatomaceous earth, and the like. The average particle diameter of the inorganic porous fine particles is preferably 0.01 μm or more and 10 μm or less, more preferably 0.05 μm or more and 5 μm or less. Further, in order to support the photocatalytic substance on the inorganic porous particles, it is preferred to implement the table. For the surface treatment, the aforementioned surface treatment application is a sol-gel film production step by means of a metal alkoxide containing a photocatalytic substance.

The thickness of the film containing the photocatalyst is preferably 0.1 μm or more and 10 μm or less. When the thickness is less than 0.1 μm, sufficient antifouling property cannot be obtained. On the other hand, when it exceeds 10 μm, the flexibility of the antifouling layer is lowered, and cracking is likely to occur.

Further, in the film subjected to the hydrophilic surface treatment, since the outer surface of the antifouling layer is hydrophilic, when water droplets adhere to the surface of the radioactive protective sheet 1, the surface tension of the water droplet can be reduced. Therefore, the water droplets become a large area of the water film, and even if dirt such as radioactive substances adheres, it can be washed away by rain or the like to keep the outer surface of the radioactive protective sheet 1 clean. Specific examples of the hydrophilic surface treatment include a method of applying a hydrophilic material such as silicone or a titanium phosphate compound.

Further, the film which is subjected to the antistatic treatment described above makes it difficult for the outer surface of the radioactive protective sheet 1 to generate static electricity. As a result, it is difficult to adsorb dust and dust in the air adsorbed by the electrostatic adsorption on the outer surface of the antifouling layer, and it is difficult to adsorb the radioactive substance on the outer surface of the radioactive protective sheet 1. As a specific method of antistatic treatment, coating the outer surface of the radioactive protective sheet 1 with tin oxide, cerium oxide, cerium oxide-zinc oxide complex, cerium oxide-tin oxide complex (ATO), indium oxide-oxidation Tin composite A method of coating a conductive metal oxide fine particle such as (ITO).

Further, in the radioactive protective sheet 1, various additives other than the above-described range and which do not impair the object of the present invention may be added. Examples of the various additives as described above include dyes, pigments, inorganic reinforcing agents, plasticizers, processing aids, ultraviolet absorbers, light stabilizers, lubricating oils, waxes, crystallization nucleating agents, mold release agents, and hydrolysis. Inhibitors, anti-blocking agents, antistatic agents, anti-fogging agents, antibacterial agents, rust inhibitors, ion trapping agents, flame retardants, flame retardant additives, inorganic fillers, organic fillers, and the like.

The upper limit of the amount of ventilation of the radioactive protective sheet 1 is, for example, preferably 60 L/m 2 /sec, more preferably 50 L/m 2 /sec. On the other hand, the lower limit of the aeration amount is preferably 20 L/m 2 /sec, and more preferably 30 L/m 2 /sec. When the ventilation amount of the radioactive protection sheet 1 is larger than the above upper limit value, the air permeability of the radioactive protection sheet 1 is too high, and it is possible to transmit fine radioactive dust and expose the wearer to radiation; When the amount of ventilation of the radioactive protective sheet 1 is less than the above lower limit, the air permeability is insufficient, and heat and steam generated by the wearer are not sufficiently dissipated to the outside.

The moisture permeability of the radioactive protective sheet 1 is, for example, preferably 100 g/m 2 /24 hours or less, more preferably 50 g/m 2 /24 hours or less, particularly preferably 10 g/m 2 /24 hours or less, which is excellently non- Moisture permeability. If the moisture permeability of the radioactive protective sheet 1 is greater than the above upper limit, sufficient radiation masking effect cannot be ensured due to the transmission of radioactive moisture, and the wearer or the like is exposed. radiation. Further, the lower limit of the moisture permeability of the radioactive protective sheet 1 is preferably 1 g/m 2 /24 hours or more. In addition, the moisture permeability here is a measured value measured under conditions of 40 ° C and a relative humidity of 90% according to JIS Z0208 cup method.

(radioactive protective clothing)

The radioactive protective sheet 1 can be suitably used as a raw material for radioactive protective clothing by cutting and sewing by a known method. Since the aforementioned radioactive protective clothing can prevent the radioactive substance from adhering to the wearer or the like, the wearer can effectively protect the radiation. Further, the radioactive protective suit made of the radioactive protective sheet 1 is provided with the radiation mask layer 2, so that the radiation in daily life can be masked, and the wearer can be simply protected from exposure to radiation.

(advantage)

Since the radioactive protective sheet 1 composed of the above is provided with the radiation mask layer 2 containing chlorosulfonated polyethylene and radiation mask particles, the radiation mask layer 2 can effectively protect the wearer and the like from daily life. Radiation in. In addition, since the radioactive protective sheet 1 contains chlorosulfonated polyethylene, it has excellent weather resistance, ozone resistance, chemical resistance, and the like, and is suitable for use in an article for long-term outdoor use. Further, since the chlorosulfonated polyethylene is excellent in color stability and exhibits rubbery elasticity at room temperature, it is easy to process into an article of clothing such as a jacket, a hat, a glove, and the like, and has a good wearing feeling when worn. Further, since the radioactive protective sheet 1 is provided with an antifouling layer on the outermost layer, the antifouling property of the radioactive protective sheet 1 can be improved, and therefore, The wearer or the like can effectively prevent radioactivity, and can effectively prevent secondary pollution caused by unintentional introduction of radioactive substances adhering to the radioactive protective sheet 1 into other places.

(Method of Manufacturing Radioactive Protective Sheet 1)

The method for producing the radioactive protective sheet 1 has a material preparation step of dispersing radiation mask particles in a chlorosulfonated polyethylene as a binder using a solvent to prepare a radiation mask layer forming material, and a sheet forming step of irradiating the radiation The mask layer forming material is molded into a sheet-like body; and the antifouling layer forming step forms an antifouling layer on one surface of the sheet-like body obtained in the sheet forming step.

Examples of the material preparation step include a method in which a chlorosulfonated polyethylene, the radiation mask particles, and a solvent are introduced into a stirrer to prepare a radiation mask layer forming material.

The solvent is not particularly limited, and examples thereof include water and an organic solvent. Further, as the solvent, water may be used, and a latex in which chlorosulfonated polyethylene is dispersed may also be used.

The sheet forming step may be a method of applying a radiation mask layer forming material obtained in the above-described material preparation step to a continuously flowing process paper to form a sheet-like body. As a method of applying the radiation mask layer forming material to the process paper, a known method such as a slit coating method, Roll coating method, knife coating method, air knife coating method, flow coating method, gravure coating method, spray method or bar coating method. Further, in addition to the above, for example, a casting solution method (solution casting method), a melt extrusion method, a calender molding method, a compression molding method, a T-die method, an inflation method (inflation method), or the like may be employed. Other examples include a method in which the radiation mask layer forming material is dropped from a filling machine onto a process paper, and the process paper on which the radiation mask layer forming material is dropped is vibrated, and the radiation mask layer forming material is formed into a uniform sheet shape. However, even if the viscosity of the radiation mask layer forming material is high, it can be applied, and it is preferable to use a roll coating method in which the coating width is easily changed. Further, the sheet forming step includes a step of drying the applied radiation mask layer forming material, and the drying step may be a known drying method such as natural drying or hot air drying.

In the step of forming the antifouling layer, for example, the photocatalytic substance supported on the inorganic porous fine particles is contained and dispersed in a suitable binder, and then applied to one surface of the sheet body obtained in the sheet forming step. Method, etc. As a method of applying the photocatalytic substance dispersed in the binder to the sheet, for example, a coating method used in the sheet forming step described above can be used.

[Second Embodiment]

(radioactive protective sheet 11)

Next, the radioactive protective sheet 11 according to the second embodiment of the present invention will be described below with reference to Fig. 2 .

The radioactive protective sheet 11 of Fig. 2 is composed of a radiation mask layer 12 containing chlorosulfonated polyethylene and (a) a tungsten or tungsten compound, and a radiation mask layer 13 containing chlorosulfonated polyethylene and (b) ruthenium or osmium compound. Composition. The radioactive protection sheet 11 is a laminate in which the radiation mask layer 12 and the radiation mask layer 13 are laminated. This radioactive protective sheet 11 is composed only of the above laminated body.

The upper limit of the average thickness of the radiation mask layer 12 is preferably 1 mm, more preferably 700 μm, and particularly preferably 500 μm. On the other hand, the lower limit of the average thickness of the radiation mask layer 12 is preferably 10 μm, more preferably 100 μm, and most preferably 300 μm. If the average thickness of the radiation mask layer 12 is larger than the above upper limit value, the radioactive protective sheet 11 becomes thick, which may lower the handleability. On the other hand, if the average thickness of the radiation mask layer 12 is less than the aforementioned lower limit value, it is difficult to form a uniform radiation mask layer 12 in the manufacturing step.

The foregoing relates to the average thickness of the radiation mask layer 13 which is the same as the average thickness of the aforementioned radiation mask layer 12.

Further, the type (a) of the tungsten or tungsten compound contained in the radiation mask layer 12 and the (b) yttrium or lanthanum compound contained in the radiation mask layer 13 are the same as those of the first embodiment described above ( a) The tungsten or tungsten compound and (b) the ruthenium or osmium compound are respectively the same. Furthermore, the proportion and the area density of the radiation mask particles in the radiation mask layer 12 and the radiation mask layer 13 (the total of the radiation mask particles contained in the two layers 12, 13 in the unit area) The same as the radiation mask layer 2 in the foregoing first embodiment.

(advantage)

Since the radiation protection sheet 11 is formed by laminating the radiation mask layer 12 and the radiation mask layer 13, the radiation protection by the wearer or the like can be performed in the same manner as the radiation protection sheet 1 of the first embodiment. Further, since the (a) tungsten or tungsten compound mainly exhibits black color, the (b) ruthenium or osmium compound mainly exhibits white color or colorlessness, and therefore, one surface of the radioactive protection sheet 11 is different from the color of the other surface, and may be suitable. The outer surface color of the radioactive protective sheet 11 is selected. Specifically, when the radioactive protective sheet 11 is used for an article in which the stain is not conspicuous, the outer surface may be provided with the radiation mask layer 12, and conversely, when the article is preferably a bright color, the outer surface may be configured as described above. Radiation mask layer 13. Further, when the outer surface of the radioactive protective sheet 11 is provided with the radiation mask layer 13, a pigment such as red or blue other than the above (b) bismuth or bismuth compound may be added, or the radiation mask layer may be added. The outer surface side printing pattern or the like imparts creativity to the radioactive protective sheet 11. As described above, since the above-described radioactive protective sheet can be imparted with creativity, each of the radioactive protective sheets can be distinguished according to the appearance imparted. That is, it may be set to distinguish the content of the radiation mask particles or the size of the radioactive protection sheet (the size of the coverage surface formed by the radioactive protection sheet) or the like according to the outer surface color.

(Method of Manufacturing Radioactive Protective Sheet 11)

The method for producing the radioactive protective sheet 11 is not particularly limited and may be There are, for example, a material preparation step of separately preparing a radiation mask layer forming material as a material of the radiation mask layer 12 and a radiation mask layer forming material as a material of the radiation mask layer 13; and a sheet forming step, which will be described above The radiation mask layer forming material forms a sheet-like body. The foregoing sheet forming step includes a step of forming a radiation mask layer forming material obtained by the foregoing material preparation step to form the radiation mask layer 12, and the radiation mask layer 12 is laminated on the radiation mask layer 12 by another radiation mask layer. The step of forming a radiation mask layer 13 made of a material. Here, the aforementioned material preparation step and the sheet forming step may respectively use, for example, substantially the same method as the material preparation step and the sheet forming step used in the foregoing first embodiment.

As the aforementioned sheet forming step, for example, a radiation mask layer 12 is first formed on the process paper, and a radiation mask layer forming material of a material forming the radiation mask layer 13 is coated on the surface of the radiation mask layer 12 to laminate radiation. The method of the mask layer 13 and the like. In addition, in contrast, a radiation mask layer 13 may be formed on the process paper, and a radiation mask layer forming material of the material forming the radiation mask layer 12 may be coated on the surface of the aforementioned radiation mask layer 13 to laminate the radiation mask layer. 12. Further, in addition to the foregoing methods, a method of separately forming the radiation mask layer 12 and the radiation mask layer 13, and then laminating and bonding them by a thermal bonding method or a binder may be employed.

[Third embodiment]

(radioactive protective sheet 21)

Next, a radioactive protective sheet for a third embodiment of the present invention The material will be described below with reference to Fig. 3 .

The radioactive protective sheet 21 of FIG. 3 has a substrate layer 22 in which a radiation mask layer is laminated, specifically, a substrate layer 22, a radiation mask layer 13, and a radiation mask layer 12 are laminated in this order. More specifically, the radiation mask layer 12 and the base material layer 22 are laminated by sandwiching the radiation mask layer 13 so as to be located at the outermost layer of the radiation protection sheet 21.

The base material layer 22 is laminated on one surface of the radioactive protection sheet 21 in order to improve the strength of the radioactive protection sheet 21, and is composed of a knitted fabric, a woven fabric or the like. The fiber constituting the base material layer 22 as described above is not particularly limited, and examples thereof include polyester fiber, cellulose acetate fiber, polyamide fiber, aromatic polyamide fiber, carbon fiber, rayon fiber, acrylic fiber, and polyurethane fiber. , polyparaphenylene terephthalamide fiber, high density polyethylene fiber, cotton, hemp or wool, glass fiber, carbon fiber and the like. Among them, cotton, polyester fiber, polyparaphenylene terephthalamide fiber, high density polyethylene fiber, and more preferably cotton and polyester fiber are preferable. Further, the aforementioned fibers may be subjected to a brushing treatment.

The thickness of the base material layer 22 is not particularly limited, and may be, for example, 1 mm or less, preferably 0.1 mm or more and 1 mm or less, more preferably 0.2 mm or more and 0.5 mm or less. If the thickness of the base material layer 22 is less than the lower limit value, the durability of the radioactive protection sheet 21 may be lowered. On the other hand, if the thickness of the base material layer 22 is larger than the upper limit value, the release is performed. The radiation protective sheet 21 becomes heavy and the handleability is lowered. Further, the thickness of the base material layer 22 is an average value of measurement results at any five positions in a circle having a radius of 2 cm using a trade name "dial thickness gauge DS-1211" (manufactured by Niigata Seiki Co., Ltd.).

Further, the radiation mask layer 12 and the radiation mask layer 13 in the radioactive protection sheet 21 may have the same structure as the radiation mask layer 12 and the radiation mask layer 13 in the foregoing second embodiment.

(advantage)

Since the radioactive protection sheet 21 further includes the base material layer 22 on one surface of the radioactive protection sheet 11 in the second embodiment, the strength and durability of the radioactive protection sheet 21 can be improved. Further, when the radioactive protective sheet 21 is used as a clothing material such as a radioactive protective clothing, for example, since the base material layer 22 is provided on the side contacting the wearer, the hand feeling and the wearing comfort can be improved.

(Method of Manufacturing Radioactive Protective Sheet 21)

The method for producing the radioactive protective sheet 21 is not particularly limited, and may have, for example, a material preparation step of separately preparing a radiation mask layer forming material as a material of the radiation mask layer 12 and a material as the radiation mask layer 13. The radiation mask layer forming material; the sheet forming step of forming the radiation mask layer forming material into a sheet-like body. As the aforementioned sheet forming step, a method comprising the steps of: preparing the aforementioned material preparation step may be employed. A radiation mask layer forming material for laminating a radiation mask layer 13 on a substrate layer 22, and a radiation mask layer made of another radiation mask layer forming material is laminated on the radiation mask layer 13 12 steps. Here, the aforementioned material preparation step may use, for example, a method substantially the same as the material preparation step used in the foregoing first embodiment. Further, the step of laminating the radiation mask layer 12 on the radiation mask layer 13 may use the same method as the second embodiment described above.

As a step of laminating the radiation mask layer 13 on the base material layer 22, for example, a method in which the radiation mask layer 13 is formed into a sheet shape and the radiation mask layer 13 is laminated on the base material layer 22 can be employed. In this case, the radiation mask layer 13 can be laminated on the base material layer 22 by so-called transfer. Specifically, the radiation mask layer forming material is applied onto the process paper of the first embodiment as described above, and the radiation mask layer forming material is semi-cured, and is bonded to the base material layer 22, and then peeled off. The process paper may be laminated with a radiation mask layer 13 on the substrate layer 22. Further, the lamination step is not limited to the above method, and a method of thermally bonding the formed base material layer 22, the radiation mask layer 12, and the radiation mask layer 13 or a method of laminating and bonding via an adhesive may be employed. Further, in the case where it is difficult for the base material layer 22 to adhere to the radiation mask layer forming material, a method of directly coating the radiation mask layer forming material on the base material layer 22 without using the process paper as described above may be employed.

[Other embodiments]

The present invention is not limited to the foregoing embodiments, except for the foregoing modes, Various changes and improvements can be implemented.

In the second embodiment described above, the radioactive protective sheet 11 is formed by laminating one layer of the radiation mask layer 12 and the radiation mask layer 13 in this order, but as shown in FIG. 4, the radiation mask layer 13 may be sandwiched. The three-layer structure (radioactive protective sheet 31) formed by laminating the radiation mask layer 12 on both sides of the radiation mask layer 13; in addition, as shown in FIG. 5, the radiation mask layer 12 and the radiation may be irradiated. The mask layer 13 is alternately laminated, and a four-layer structure (radioactive protective sheet 41) formed by laminating two layers in this order is laminated. Further, as shown in Fig. 6, the radioactive protective sheet 51 may be a radiation mask layer 2 containing (a) a tungsten or tungsten compound as a radiation masking particle and (b) a ruthenium or osmium compound. In a manner, a three-layer structure in which the radiation mask layer 12 is laminated on both sides of the radiation mask layer 2 is formed.

Further, in the third embodiment, the radioactive protection sheet 21 is laminated such that the base material layer 22 is located at the outermost surface of the radioactive protection sheet 21, but as shown in Fig. 7, the base material layer 22 may be sandwiched. The radiation shielding layer 12 and the radiation mask layer 13 are laminated in such a manner as to be disposed inside the radioactive protective sheet 61 (radioactive protective sheet 61); in addition, as shown in FIG. The cover layer 12, the radiation mask layer 13, the base material layer 22, the radiation mask layer 13, and the radiation mask layer 12 are laminated in this order (radioactive protective sheet 71).

Further, the aforementioned base material layer 22 is composed of a knitted fabric, a woven fabric, or the like, but the aforementioned base The material layer 22 may be made of other materials such as a rubber sheet, a synthetic resin sheet, a nonwoven fabric or the like. Further, in addition to lamination as in the third embodiment described above, the base material layer 22 may be buried in the middle of the radiation protection layer.

In addition to the aforementioned radioactive protective clothing, the radioactive protective sheet can also be used in articles such as raincoats, hats, gloves, boots, aprons, and the like. In addition, it can also be used as a sheet for outdoor products such as umbrellas, tents, cold-proof or waterproof sheets.

[Experimental Example 1]

As the radiation mask particles, tungsten particles were used, and the radiation mask particles were dispersed in a chlorosulfonated polyethylene as a binder using a solvent to prepare a radiation mask layer forming material (coating liquid). Further, toluene was used as the solvent, and 4% by mass of toluene was added to the total mass of the radiation mask particles and the binder.

With regard to the foregoing formulation, experiments were conducted with respect to the total mass of the binder and the radiation mask particles, varying the content of the radiation mask particles (the content of the radiation mask particles in the radiation mask layer). As a result of the experiment, as long as the content is within 85% by mass, a coating liquid suitable for coating can be obtained.

[Experimental Example 2]

As the radiation mask particles, tungsten and barium sulfate were used, and the radiation mask particles were dispersed in a chlorosulfonated polyethylene as a binder using a solvent to prepare a radiation mask layer forming material (coating liquid). In addition, the solvent uses toluene, 4% by mass of toluene was added with respect to the total mass of the radiation mask particles and the binder. When the above preparation was carried out, the content of the radiation mask particles (the content of the radiation mask particles in the radiation mask layer) was 80% by mass with respect to the total mass of the binder and the radiation mask particles.

With respect to the above preparation, the ratio of tungsten to barium sulfate (ratio of barium sulfate to tungsten) was tested as shown in Table 1 below. The experimental results show that when the ratio of barium sulfate to tungsten exceeds 60% by mass (two rows from the top in Table 1), it becomes a solidified state. Therefore, it is preferably 50% by mass or less, more preferably 43% by mass. the following. Further, it is more preferable that the cured state is not generated in the case of 34% by mass or less (the fourth row or less from the top in Table 1).

[Industrial Applicability]

As described above, the radioactive protective sheet of the present invention can cover radiation reliably and simply, and can be easily used in daily life.

11‧‧‧ Radioactive protective sheet

12‧‧‧First Radiation Mask

13‧‧‧Second Radiation Mask

Claims (8)

A radioactive protective sheet comprising: a radiation mask layer, the radiation mask layer comprising: a binder containing chlorosulfonated polyethylene as a main component; and a radiation mask particle dispersed in the binder; The radiation mask layer is provided with: (a) a radiation mask layer containing a tungsten or tungsten compound; and (b) a radiation mask layer containing a ruthenium or osmium compound. The radioactive protective sheet according to claim 1, wherein the radiation masking particles are barium sulfate. The radioactive protective sheet according to claim 1, wherein the content of the radiation mask particles in the radiation mask layer is 30% by mass or more and 85% by mass or less. The radioactive protective sheet according to the first aspect of the invention, wherein the radiation mask particles in the radiation mask layer have an area density of 0.1 g/cm ² or more and 1 g/cm ² or less. The radioactive protective sheet according to claim 1, wherein the radioactive protective sheet further comprises a substrate layer. The radioactive protective sheet according to any one of claims 1 to 5, wherein the radioactive protective sheet further comprises an antifouling layer on the outermost layer. The radioactive protective sheet according to claim 6, wherein the antifouling layer is a resin layer made of an olefin resin as a main component. A method for producing a radioactive protective sheet, comprising: a material preparation step of using a solvent as a radiation masking particle (a) a tungsten or tungsten compound or (b) a ruthenium or osmium compound dispersed in a binder containing chlorosulfonated polyethylene as a main component to prepare a radiation mask layer forming material; and a sheet forming step of forming the aforementioned radiation mask layer The material is formed into a sheet body; in the sheet forming step, a radiation mask layer containing (a) a tungsten or tungsten compound-containing layer and (b) a ruthenium or osmium compound is formed.