JP3914720B2 - Radiation shield, method for producing the shield, and flame-retardant radiation shield - Google Patents

Description

配合割合、遮蔽体１ｍｍ当りの鉛当量、引張強さ、引裂強さ、製品厚み０．５ｍｍにおける耐折性、及びピンホールの発生状況の測定結果を下記の表２に示した。
【００３５】
【表２】

（１）表１より明らかなように、Ｓｂ₂ Ｏ₃ やＳｎが１０〜９０％配合された実施例１〜１８のものでは、厚み１ｍｍ当りの鉛当量が０．０３ｍｍＰｂ以上あり、Ｐｂを配合しなくても、厚みを調整することにより、防護エプロン、防護コート、甲状腺防護具、防護手袋等における規格値（ＪＩＳＺ４８３１）の０．２５ｍｍＰｂを満たすことが十分に可能である。一方、Ｓｂ₂ Ｏ₃ やＳｎを配合しなかった比較例１、３では、放射線遮蔽能力がなく、又Ｓｂ₂ Ｏ₃ やＳｎを１００％配合し、樹脂を配合しなかった比較例２、４では、放射線遮蔽能力は大きいものの、成形することが不可能であった。なおＳｂ₂ Ｏ₃ やＳｎを９５％（樹脂が５％）配合した場合も成形することはできなかった。他方、ＷＯ₃ を１０〜９０％配合した実施例１９〜２７では、１ｍｍ当りの鉛当量が０．０４〜０．３４ｍｍＰｂであった。
（２）表２より明らかなように、ＷＯ₃ 、Ｓｂ₂ Ｏ₃ 、及びＳｎが配合された実施例２８のものは、ピンホールの発生が少なく、Ｐｂが配合された比較例７のものと略同様の鉛当量を得ると同時に、引張強さ、引裂強さ、耐折性を確保することができた。
【図面の簡単な説明】
【図１】本発明に係る放射線遮蔽体の実施の形態（１）を模式的に示した断面図である。
【図２】実施の形態（２）に係る放射線遮蔽体を模式的に示した断面図である。
【図３】実施の形態（２）に係る放射線遮蔽体の製造方法を説明するために模式的に示した断面図である。
【図４】従来の放射線遮蔽シートを模式的に示した断面図である。
【符号の説明】
１０ 放射線遮蔽シート
１１ 塩化ビニル樹脂
１２ Ｗ金属粉末
１３ Ｓｂ金属粉末
１４ Ｓｎ金属粉末[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radiation shield , a method for manufacturing the radiation shield , and a flame retardant radiation shield, and more specifically, for example, an X-ray generator, nuclear equipment, a radioactive material container, a radioactive waste container, and the like. Structural members, X-ray engineers, doctors, researchers, non-destructive inspectors, patients undergoing X-ray diagnosis and radiation therapy, workers handling and handling radioactive materials and radioactive waste, nuclear power A radiation shield used to prevent accident handlers of related equipment from being exposed to radiation such as X-rays, α-rays, β-rays, and γ-rays, a method for manufacturing the radiation shield , and flame retardancy It relates to a radiation shield .
[0002]
The radiation shield is a concept including a thin sheet having flexibility, a thick sheet that cannot be called a sheet, and a plate having rigidity.
[0003]
[Prior art]
FIG. 4 is a cross-sectional view schematically showing a conventional radiation shielding sheet of this type, in which 91 indicates a thermoplastic resin such as a vinyl chloride resin. The thermoplastic resin 91 is formed in a thin sheet shape having a thickness t of usually about 0.5 mm. In the thermoplastic resin 91, lead (hereinafter referred to as Pb) powder 92 is blended and dispersed. A radiation shielding sheet 90 is configured including these thermoplastic resin 91, Pb powder 92, and the like.
[0004]
Although not shown, the radiation shielding sheet 90 is cut into a predetermined size, wrapped in a cloth, etc., and then sewn into a predetermined shape through the cloth, etc. Formed and worn as clothing. Alternatively, it is used as a cover or curtain in close contact with the radiation source or indirectly covering the radiation source.
[0005]
Although not shown, X-ray generators, nuclear-related equipment, radioactive material containers, radioactive waste containers, etc. have radiation shields containing Pb powder mixed and dispersed in thermosetting resin plates as structural members. Yes.
[0006]
[Problems to be solved by the invention]
In the above-described conventional radiation shielding sheet 90 and radiation shielding body, Pb powder 92 and lead zincide are blended, and Pb poisoning and Pb pollution are likely to occur during each process of manufacture, use, and disposal. In addition, since the radiation shielding sheet 90 and the radiation shielding body are thin, pinholes (not shown) that are inevitably generated in the manufacturing process easily penetrate the radiation shielding body, and there is a risk that radiation will pass through the pinholes. There was also a problem that there was.
[0007]
The present invention has been made in view of the above problems, and ensures radiation shielding performance without blending Pb, and has tensile strength, tear strength, folding resistance, flame resistance, and penetration of pinholes. An object of the present invention is to provide a radiation shielding body in which the above is prevented and a method for manufacturing the same.
[0008]
[Means for solving the problems and effects thereof]
In order to achieve the above object, the radiation shielding body (1) according to the present invention includes a metal single powder or compound powder of antimony (hereinafter referred to as Sb) and tin (hereinafter referred to as Sn) in a resin, It is characterized in that a plurality of radiation shielding sheets formed by blending at least one kind are stacked, laminated, and pinholes are crushed and removed .
According to the radiation shield (1) described above, since the Sb and Sn metal simple substance powders or compound powders all easily absorb or reflect radiation, it is not necessary to add Pb, and radiation can be shielded. At the same time, the occurrence of Pb poisoning and Pb pollution can be prevented. Moreover, flame retardance can be improved by Sb.
In addition, since a plurality of the radiation shielding sheets are laminated and laminated, the pinholes that are likely to be generated in the shielding sheet are crushed and the pinholes are connected to penetrate the shielding sheet. Can be greatly reduced. As a result, it is possible to prevent the radiation from being transmitted through the pinhole and to reliably prevent the transmission of the radiation.
[0009]
The radiation shield (2) according to the present invention is characterized in that in the radiation shield (1), a single metal powder or compound powder of tungsten (hereinafter referred to as W) is further blended.
According to the radiation shielding body (2) described above, the presence of the metal simple substance powder or compound powder of W can improve the radiation shielding property, and these metal simple substance powder or compound powder are relatively easy to price. Therefore, an increase in manufacturing cost can be suppressed.
[0010]
In the radiation shield (3) according to the present invention, in the radiation shield (1) or (2), the blending ratio of the powder is 10 to 90 parts by weight when W is WO ₃ and Sb is Sb ₂ O. ₃ is 10 to 90 parts by weight, and Sn is in the range of 10 to 90 parts by weight.
According to the radiation shield (3) described above, the W, Sb, and Sn powders are blended in appropriate amounts in the resin, so that radiation can be reliably shielded and the strength as a sheet can be ensured. .
[0011]
In any of the radiation shields (1) to (3), the resin is preferably composed of any one of a thermoplastic vinyl resin, a polyurethane resin, and a polyethylene resin. According to the shield, the strength as a sheet can be sufficiently secured while maintaining plasticity, and the shield can be applied to protective clothing, a cover, a curtain, etc. for shielding radiation.
[0012]
In any one of the radiation shields (1) to (3), the resin is preferably composed of any one of a thermosetting epoxy resin, a phenol resin, and a silicone resin. According to the radiation shielding body, sufficient strength can be secured, and it can be applied to a radiation shielding structural member or the like.
[0014]
A method for producing a radiation shield according to the present invention is any one of the radiation shields (1) to (3) described above, wherein a single metal powder and / or a compound powder are mixed in a resin raw material. After manufacturing a sheet-shaped radiation shield by extrusion molding method, calendering, coating method or die molding method, a plurality of the radiation shields are laminated and laminated to crush and remove pinholes. It is characterized by doing.
By adopting the extrusion molding method, calendering, coating method or mold molding method, the sheet-shaped radiation shield can be easily manufactured, and in the sheet-shaped radiation shield by the laminating process. Lamination can be performed while removing the generated pinholes, and the laminated shield can reliably prevent penetration of the pinholes, and a radiation shield excellent in radiation shielding ability can be manufactured. The flame retardant radiation shield (1) according to the present invention includes at least one metal element powder or compound powder of antimony and at least one kind of metal element powder or compound powder of tin and tungsten. It is characterized in that a plurality of flame retardant radiation shielding sheets blended with is laminated, laminated, and pinholes are crushed and removed .
According to the flame retardant radiation shielding body (1) described above, the Sb single metal powder or the compound powder easily absorbs or reflects radiation, so that it is not necessary to add Pb and shield radiation. In addition, the occurrence of Pb poisoning and Pb pollution can be prevented, and the flame retardancy can be enhanced by Sb, which can be particularly suitable for applications requiring flame retardancy.
In addition, since a plurality of the flame-retardant radiation shielding sheets are laminated, pinholes that are likely to occur in the flame-retardant radiation shielding sheet are crushed, and these pinholes are connected to form the difficulty. Penetrating through the flammable radiation shielding sheet can be greatly reduced. As a result, it is possible to prevent the radiation from being transmitted through the pinhole and to reliably prevent the transmission of the radiation.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a radiation shield and a method for manufacturing the same according to the present invention will be described below with reference to the drawings. In addition, the same code | symbol shall be attached | subjected to the component which has the same function as a prior art example.
FIG. 1 is a cross-sectional view schematically showing a radiation shielding sheet as a radiation shielding body according to the embodiment (1), in which 11 denotes a vinyl chloride resin. The vinyl chloride resin 11 is formed into a thin sheet having a thickness t of about 0.5 mm. In the vinyl chloride resin 11, W is in the form of WO ₃ , Sb is in the form of Sb ₂ O ₃ , and Sn is Three types of metal powders 12 to 14 are blended and dispersed as Sn.
[0016]
The mixing ratio of _{WO 3, Sb 2 O 3,} Sn powder 12 to 14, WO ₃ powder 12 10-90 parts, _Sb 2 _{O 3} powder 13 10 90 wt parts, Sn powder 14 is 10 to 90 parts desirable. If the blending ratio is higher than this, the blending ratio of the vinyl chloride resin 11 is relatively insufficient, and the tensile strength, tear strength, and folding resistance of the sheet are not sufficient. The radiation shielding sheet 10 includes the three kinds of metal powders 12, 13, 14 and the like such as the vinyl chloride resin 11, WO ₃ , Sb ₂ O ₃ , and Sn.
[0017]
When manufacturing the radiation shielding sheet 10 configured as described above, a predetermined amount of a vinyl chloride resin raw material, metal powder, a plasticizer, an adhesive component, and the like are first mixed using a mixer. Next, the mixture is molded by an extrusion molding method, a calendering method, a coating method, a mold molding method, or the like to produce a radiation shielding sheet 10 having a thickness t of about 0.5 mm.
[0018]
WO ₃ , Sb ₂ O ₃ , and Sn powders 12 to 14 are all easy to shield radiation, can shield radiation without blending Pb, and can prevent the occurrence of Pb poisoning and Pb pollution. .
[0019]
Further, in the radiation shielding sheet 10, since a sufficient amount of WO ₃ , Sb ₂ O ₃ and Sn powders 12 to 14 is blended in the vinyl chloride resin 11, radiation can be reliably shielded.
[0020]
In addition, since appropriate amounts of WO ₃ , Sb ₂ O ₃ and Sn powders 12 to 14 are blended in the vinyl chloride resin 11, sufficient tensile strength, tear strength, and folding resistance are ensured while maintaining plasticity. can do. Further, due to the presence of the Sb ₂ O ₃ powder 13 , flame retardancy as a sheet can be sufficiently ensured. In _addition, since WO _3, Sb ₂ O _3, is a relatively cheap price of Sn powder 12 to 14, it is possible to suppress up the manufacturing cost.
[0021]
FIG. 2 is a cross-sectional view schematically showing the radiation shield according to the embodiment (2), in which 20a shows a radiation shield sheet. The radiation shielding sheet 20a is formed in a thin sheet shape of about t / 2, where t is the total sheet thickness as a product. As in the case of the radiation shielding sheet 10, the radiation shielding sheet 20 a is configured by mixing and dispersing three kinds of metal powders 22 a to 24 a of WO ₃ , Sb ₂ O ₃ , and Sn in a vinyl chloride resin 21 a. Yes. The radiation shielding sheet 20 is configured by laminating these two radiation shielding sheets 20a and 20a.
[0022]
When manufacturing the radiation shielding sheet 20 configured as described above, first, the radiation shielding sheets 20a and 20a having a thickness of about t / 2 are manufactured in the same manner as the radiation shielding sheet 10 shown in FIG.
[0023]
Next, the shielding sheets 20a and 20a are laminated and integrated using the press machine shown in FIG. In the figure, 31 indicates a bed. A driving ram 32 is disposed above the bed 31 so as to be driven in the direction of arrows AB in the figure. A press machine main body 30a is configured including the bed 31, the drive ram 32, and the like. On the other hand, between the bed 31 and the drive ram 32, substrates 33 to 35 having a substantially rectangular parallelepiped plate shape are mounted and arranged, and the substrates 33 to 35 are equipped with heating means (not shown). . A plurality of sets of radiation shielding sheets 20a and 20a are stacked between the substrates 33 to 35, and the radiation shielding sheets 20a and 20a are sandwiched between stainless steel separation plates 36a and 36a. A jig 30b is configured including the substrates 33 to 35, the separation plate 36a, and the like.
[0024]
When the radiation shielding sheet 20 is manufactured using the radiation shielding sheets 20a and 20a by using the press machine, first, the substrates 33 and 34 are mounted on the bed 31 and the drive ram 32, respectively. Next, the sheets 20a and 20a sandwiched between the separation plates 36a and 36a are stacked, and after the substrate 35 is disposed at a predetermined position, the sheets 20a and 20a sandwiched between the separation plates 36a and 36a are further stacked. Thereafter, the heating means is operated to raise the temperature of the sheets 20a and 20a to a predetermined temperature via the substrates 33 to 35 and the separation plates 36a and 36a, and then the drive ram 32 is driven in the direction of arrow B in the figure to A predetermined pressure is applied to 20a and thermocompression bonded. Then, by cooling, the radiation shielding sheets 20a and 20a are integrated, and the radiation shielding sheet 20 having a thickness t is manufactured.
[0025]
In the radiation shielding sheet 20 according to the embodiment (2), since the radiation shielding sheets 20a and 20a are laminated, it is possible to greatly reduce the penetration of pinholes through the radiation shielding sheet 20. . Further, pinholes that are likely to occur in the manufacturing process of the sheets 20a and 20a can be crushed and removed in the stacking process. As a result, it is possible to prevent the radiation from being transmitted through the pinhole and shield the radiation more reliably.
[0026]
In addition, in the radiation shielding sheet 20 and the manufacturing method according to the embodiment (2), the case where the two radiation shielding sheets 20a and 20a are laminated has been described. In the embodiment, there may be three, four,... As the number of stacked sheets increases, the probability of sheet penetration through pinholes can be lowered, but manufacturing becomes difficult little by little.
[0027]
Moreover, in the manufacturing method of the radiation shielding sheet 20 which concerns on Embodiment (2), although the case where the press process was given as a lamination process was demonstrated, in another embodiment, the roll rolling method including a heating process, or adhesion | attachment Adhesive processing using an agent may be performed.
[0028]
In addition, in the radiation shielding sheets 10 and 20 according to the embodiments (1) and (2), the description has been given of the case where WO ₃ , Sb ₂ O ₃ , Sn powders 12 to 14 and 22a to 24a are used. In another embodiment, any one of the Sb ₂ O ₃ powders 13 and 23a and the Sn powders 14 and 24a may be blended and dispersed. Or either WO ₃ powder 12, 22a and Sb ₂ O ₃ powder 13, 23a, WO ₃ powder 12, 22a and Sn powder 14, 24a, Sb ₂ O ₃ powder 13, 23a and Sn powder 14, 24a Two kinds of metal powders may be blended and dispersed.
[0029]
In the radiation shielding sheets 10 and 20 according to the embodiments (1) and (2), W is WO ₃ , Sb is Sb ₂ O ₃ , and Sn is Sn metal powders 12 to 14 and 22a to 24a. Although the case has been described, in another embodiment, it may be a compound powder such as a simple metal powder of W or Sb, an oxide of Sn, or a carbide, alloy or the like of each.
[0030]
In the radiation shielding sheets 10 and 20 according to the embodiments (1) and (2), the case where the thermoplastic vinyl chloride resins 11 and 21a are used as the resin has been described. However, in another embodiment, Alternatively, another vinyl resin (for example, vinyl acetate resin), polyurethane resin, polyethylene resin, or the like may be used. In that case, it is necessary to change the plasticizer and the adhesive component in accordance with the resin to be used.
[0031]
In the radiation shielding sheets 10 and 20 according to the embodiments (1) and (2), the case where the thermoplastic vinyl chloride resins 11 and 21a are used as the resin has been described. However, in another embodiment, A thermosetting epoxy resin, a phenol resin, a silicone resin, or the like may be used. In that case, the catalyst components are changed according to the resin used.
[0032]
[Examples and Comparative Examples]
Under the following conditions, radiation shields according to Examples and Comparative Examples were manufactured, and lead equivalent, tensile strength, tear strength, and shield product thickness (0.5 mm) in the shield 1 mm thickness under the following experimental conditions. The results of investigating the folding resistance and the occurrence of pinholes will be explained.
[0033]
The manufacturing method used a mixer to mix and mix the resins and metal powders shown in Tables 1 and 2 below with a predetermined amount of plasticizer, adhesive components, etc., and manufactured a sheet with a predetermined thickness by an extrusion molding method. Thereafter, two sheets of this sheet were stacked and laminated by a press. In Examples 1 to 18, 90 to 10% of vinyl chloride resin and 10 to 90% of Sb ₂ O ₃ or Sn were blended. Example 28 22% of vinyl chloride resin, WO ₃ 13%, the _Sb 2 _{O 3} 30% and 35% blended Sn. On the other hand, in Comparative Examples 1 and 3, the vinyl chloride resin was 100%, and Sb ₂ O ₃ or Sn was not blended. In Comparative Examples 2 and 4, no vinyl chloride resin was blended, and Sb ₂ O ₃ or Sn was blended at 100%. In Examples 19 to 27, 10 to 90% of vinyl chloride resin and 10 to 90% of WO ₃ were blended. On the other hand, in Comparative Example 5, the vinyl chloride resin was 100%, and WO ₃ was not blended. In Comparative Example 6, no vinyl chloride resin was blended, and WO ₃ was blended at 100%. In Comparative Example 7 , 20% of vinyl chloride resin and 80% of Pb were blended, and lamination was not performed. Measurement of lead equivalent, tensile strength, tear strength, and folding resistance is based on JIS-Z4801 (1991), and the occurrence of pinholes is based on JIS-Z4501-2 (film size 25.4cm x 30.5cm) ,Carried out.
The blending ratio and the lead equivalent per 1 mm thickness of the shield are shown in Table 1 below.
[0034]
[Table 1]

Table 2 below shows the measurement results of the blending ratio, lead equivalent per 1 mm of shield, tensile strength, tear strength, folding resistance at 0.5 mm product thickness, and occurrence of pinholes.
[0035]
[Table 2]

(1) As is clear from Table 1, in Examples 1 to 18 in which 10 to 90% of Sb ₂ O ₃ or Sn is blended, the lead equivalent per 1 mm thickness is 0.03 mm Pb or more, and Pb is blended. Even if not, it is possible to meet the standard value (JISZ4831) of 0.25 mmPb in protective apron, protective coat, thyroid protective equipment, protective gloves, etc. by adjusting the thickness. On the other hand, Comparative Examples 1 and ₃ in which Sb ₂ O ₃ and Sn were not blended had no radiation shielding ability, and Sb ₂ O ₃ and Sn were blended in 100% and no resin was blended. Then, although the radiation shielding ability was large, it was impossible to mold. In addition, when Sb ₂ O ₃ and Sn were blended in 95% (5% resin), molding could not be performed. On the other hand, in Examples 19 to 27 in which 10 to 90% of WO ₃ was blended, the lead equivalent per 1 mm was 0.04 to 0.34 mm Pb.
(2) As is clear from Table 2, Example 28 in which WO ₃ , Sb ₂ O ₃ , and Sn were blended had less pinholes and that in Comparative Example 7 in which Pb was blended. While substantially the same lead equivalent was obtained, the tensile strength, tear strength, and folding resistance could be secured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an embodiment (1) of a radiation shield according to the present invention.
FIG. 2 is a cross-sectional view schematically showing a radiation shield according to Embodiment (2).
FIG. 3 is a cross-sectional view schematically showing the method for manufacturing the radiation shield according to the embodiment (2).
FIG. 4 is a cross-sectional view schematically showing a conventional radiation shielding sheet.
[Explanation of symbols]
10 radiation shielding sheet 11 vinyl chloride resin 12 W metal powder 13 Sb metal powder 14 Sn metal powder

Claims (5)

  A plurality of radiation shielding sheets formed by blending at least one of antimony and tin metal powders or compound powders in the resin are laminated, laminated, and pinholes are crushed and removed. A radiation shield characterized by comprising:   The radiation shielding body according to claim 1, wherein the resin further contains a single metal powder or compound powder of tungsten.   The blending ratio of the powder is in the range of 10 to 90 parts by weight of tungsten as tungsten trioxide, 10 to 90 parts by weight of antimony as antimony oxide, and 10 to 90 parts by weight of tin as metal tin. Item 3. The radiation shield according to item 1 or item 2.   A single metal powder and / or compound powder is mixed into a resin raw material, a sheet-shaped radiation shield is produced by an extrusion molding method, calendering, coating method or mold molding method, and then a plurality of the radiation shields are laminated. And the manufacturing method of the radiation shielding body in any one of Claims 1-3 crushing and removing a pinhole by giving a lamination process. A plurality of flame retardant radiation shielding sheets in which at least one antimony metal powder or compound powder is blended in the resin and at least one of tin and tungsten metal powders or compound powders are further laminated. A flame retardant radiation shield characterized in that pinholes are crushed and removed by processing .

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