JP2015161667A - Cesium adsorption sheet and filtration filter for muddy water using the same - Google Patents
Cesium adsorption sheet and filtration filter for muddy water using the same Download PDFInfo
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- 229910052792 caesium Inorganic materials 0.000 title claims abstract description 171
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 title claims abstract description 170
- 238000001179 sorption measurement Methods 0.000 title claims abstract description 82
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 67
- 238000001914 filtration Methods 0.000 title claims description 45
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- 230000002285 radioactive effect Effects 0.000 claims abstract description 53
- 238000000034 method Methods 0.000 claims abstract description 34
- 239000011148 porous material Substances 0.000 claims abstract description 34
- 239000003463 adsorbent Substances 0.000 claims abstract description 29
- 239000011248 coating agent Substances 0.000 claims abstract description 22
- 238000000576 coating method Methods 0.000 claims abstract description 22
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- 239000003795 chemical substances by application Substances 0.000 claims 1
- 239000012466 permeate Substances 0.000 claims 1
- -1 cesium ions Chemical class 0.000 abstract description 10
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- SOGAXMICEFXMKE-UHFFFAOYSA-N Butylmethacrylate Chemical compound CCCCOC(=O)C(C)=C SOGAXMICEFXMKE-UHFFFAOYSA-N 0.000 description 2
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- LMAUULKNZLEMGN-UHFFFAOYSA-N 1-ethyl-3,5-dimethylbenzene Chemical compound CCC1=CC(C)=CC(C)=C1 LMAUULKNZLEMGN-UHFFFAOYSA-N 0.000 description 1
- OOHZIRUJZFRULE-UHFFFAOYSA-N 2,2-dimethylpropyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC(C)(C)C OOHZIRUJZFRULE-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
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- CFVWNXQPGQOHRJ-UHFFFAOYSA-N 2-methylpropyl prop-2-enoate Chemical compound CC(C)COC(=O)C=C CFVWNXQPGQOHRJ-UHFFFAOYSA-N 0.000 description 1
- GBJVVSCPOBPEIT-UHFFFAOYSA-N AZT-1152 Chemical compound N=1C=NC2=CC(OCCCN(CC)CCOP(O)(O)=O)=CC=C2C=1NC(=NN1)C=C1CC(=O)NC1=CC=CC(F)=C1 GBJVVSCPOBPEIT-UHFFFAOYSA-N 0.000 description 1
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- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
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- 229920000297 Rayon Polymers 0.000 description 1
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- NTXGQCSETZTARF-UHFFFAOYSA-N buta-1,3-diene;prop-2-enenitrile Chemical compound C=CC=C.C=CC#N NTXGQCSETZTARF-UHFFFAOYSA-N 0.000 description 1
- MTAZNLWOLGHBHU-UHFFFAOYSA-N butadiene-styrene rubber Chemical compound C=CC=C.C=CC1=CC=CC=C1 MTAZNLWOLGHBHU-UHFFFAOYSA-N 0.000 description 1
- CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 1
- 235000009120 camo Nutrition 0.000 description 1
- 238000009960 carding Methods 0.000 description 1
- TVFDJXOCXUVLDH-OUBTZVSYSA-N cesium-134 Chemical compound [134Cs] TVFDJXOCXUVLDH-OUBTZVSYSA-N 0.000 description 1
- TVFDJXOCXUVLDH-RNFDNDRNSA-N cesium-137 Chemical compound [137Cs] TVFDJXOCXUVLDH-RNFDNDRNSA-N 0.000 description 1
- 235000005607 chanvre indien Nutrition 0.000 description 1
- YACLQRRMGMJLJV-UHFFFAOYSA-N chloroprene Chemical compound ClC(=C)C=C YACLQRRMGMJLJV-UHFFFAOYSA-N 0.000 description 1
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- OIWOHHBRDFKZNC-UHFFFAOYSA-N cyclohexyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OC1CCCCC1 OIWOHHBRDFKZNC-UHFFFAOYSA-N 0.000 description 1
- KBLWLMPSVYBVDK-UHFFFAOYSA-N cyclohexyl prop-2-enoate Chemical compound C=CC(=O)OC1CCCCC1 KBLWLMPSVYBVDK-UHFFFAOYSA-N 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- SUPCQIBBMFXVTL-UHFFFAOYSA-N ethyl 2-methylprop-2-enoate Chemical compound CCOC(=O)C(C)=C SUPCQIBBMFXVTL-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- YAGKRVSRTSUGEY-UHFFFAOYSA-N ferricyanide Chemical compound [Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] YAGKRVSRTSUGEY-UHFFFAOYSA-N 0.000 description 1
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- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 1
- QIWKUEJZZCOPFV-UHFFFAOYSA-N phenyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OC1=CC=CC=C1 QIWKUEJZZCOPFV-UHFFFAOYSA-N 0.000 description 1
- WRAQQYDMVSCOTE-UHFFFAOYSA-N phenyl prop-2-enoate Chemical compound C=CC(=O)OC1=CC=CC=C1 WRAQQYDMVSCOTE-UHFFFAOYSA-N 0.000 description 1
- 229920000747 poly(lactic acid) Polymers 0.000 description 1
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- ZXQVPEBHZMCRMC-UHFFFAOYSA-R tetraazanium;iron(2+);hexacyanide Chemical compound [NH4+].[NH4+].[NH4+].[NH4+].[Fe+2].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] ZXQVPEBHZMCRMC-UHFFFAOYSA-R 0.000 description 1
- XOGGUFAVLNCTRS-UHFFFAOYSA-N tetrapotassium;iron(2+);hexacyanide Chemical compound [K+].[K+].[K+].[K+].[Fe+2].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] XOGGUFAVLNCTRS-UHFFFAOYSA-N 0.000 description 1
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Landscapes
- Filtering Materials (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
Abstract
Description
本発明は、放射性セシウムを含む汚染水の除染に用いるセシウム吸着シートに関するものであり、該セシウム吸着シートは、特に放射性セシウムを含む泥水の濾過に優れた効果を発揮する。 The present invention relates to a cesium adsorbing sheet used for decontamination of contaminated water containing radioactive cesium, and the cesium adsorbing sheet exhibits an excellent effect particularly in filtering muddy water containing radioactive cesium.
２０１１年３月１１日に東日本を襲った地震・津波により、福島第一原子力発電所では、深刻な原発事故が発生した。この事故により排出された放射性セシウムは、福島県内のみならず、東北・関東一円にまで飛散して問題となっている。そのため、飛散した放射性セシウムを効率よく且つ確実に除染するための方法、及び、放射性セシウムが更に拡散することを防止するための方法が、各方面において種々提供されている。 The earthquake and tsunami that hit East Japan on March 11, 2011 caused a serious nuclear accident at the Fukushima Daiichi NPS. The radioactive cesium emitted by this accident is scattered not only in Fukushima Prefecture but also in Tohoku and Kanto. Therefore, various methods are provided in various fields for efficiently and reliably decontaminating scattered radioactive cesium and for preventing further diffusion of radioactive cesium.
例えば、非特許文献１には、放射性セシウム吸着剤として、ナノサイズのフェロシアン化鉄（プルシアンブルー）を用い、このフェロシアン化鉄で木綿布を着色したものが記載されている。この材料は濾過フィルターとして水路に設置され、水中の放射性セシウムを回収することができる。また同文献には、ナノサイズのフェロシアン化鉄を合成繊維に練り込み、該繊維を用いて不織布を製造した通水性に優れる濾過フィルターも記載されている。 For example, Non-Patent Document 1 describes a nanosized iron ferrocyanide (Prussian blue) used as a radioactive cesium adsorbent and a cotton cloth colored with this ferrocyanide. This material is installed in a water channel as a filtration filter and can recover radioactive cesium in water. The document also describes a filtration filter excellent in water permeability in which nano-sized ferric ferrocyanide is kneaded into a synthetic fiber and a nonwoven fabric is produced using the fiber.
また特許文献１には、廃棄物処理場において、放射性セシウムを含有する汚染水が土壌に侵入する前に放射性セシウムを回収する遮水シート用の保護シート材が開示されている。該保護シート材は、フェロシアン化物及びフェリシアン化物を分散させたエマルジョンを、平均繊度０．５ｄｔｅｘ以下の極細繊維を用いて作製された不織布に含浸させて製造されている。特許文献２にも、同様の方法で製造した土壌除染シートが開示されている。 Patent Document 1 discloses a protective sheet material for a water shielding sheet that collects radioactive cesium before contaminated water containing radioactive cesium enters soil in a waste disposal site. The protective sheet material is manufactured by impregnating a non-woven fabric made of ultrafine fibers having an average fineness of 0.5 dtex or less with an emulsion in which ferrocyanide and ferricyanide are dispersed. Patent Document 2 also discloses a soil decontamination sheet manufactured by the same method.
このような種々の方法により、飛散した放射性セシウムは徐々に除染されている。しかし、土壌に付着した放射性セシウムを除染することは非常に難しく、放射性セシウムを土壌から高効率で除染する技術は十分に開発されていない。一般に、飛散した放射性セシウムは、主として土壌に含まれる粒径０．００２〜０．０２ｍｍのシルト及び粒径０．００２ｍｍ以下の粘土に固定されていると考えられており、酸を用いて高温下で煮出す等の方法でない限り、除染は困難と考えられている（例えば、２０１３年、第２回環境放射能除染研究発表会要旨集第１４頁「シュウ酸等を用いた汚染土壌除染法の除去率向上の検討（阿部紘子、中村秀樹他）」参照のこと）。 The scattered radioactive cesium is gradually decontaminated by such various methods. However, it is very difficult to decontaminate radioactive cesium adhering to soil, and a technique for decontaminating radioactive cesium from soil with high efficiency has not been sufficiently developed. Generally, scattered radioactive cesium is considered to be fixed mainly to silt having a particle size of 0.002 to 0.02 mm and clay having a particle size of 0.002 mm or less contained in soil. Decontamination is considered to be difficult unless the method is boiled in (for example, 2013, 2nd Environmental Radioactive Decontamination Research Presentation, 14th page “Contaminated soil removal using oxalic acid etc. (Refer to "Improvement of removal rate of dyeing method (Abe Atsuko, Nakamura Hideki et al.)").
仮に上述した技術を土壌の除染に適用しようとも、例えば、非特許文献１に記載の濾過フィルターは、水に溶解している放射性セシウムを吸着して除染するものであるため、シルトや粘土に吸着されている放射性セシウムは除染できない。また、特許文献１及び２に記載の保護シート材を用いても、極細繊維不織布は高価であり、土壌の除染フィルターとしては過剰品質であるため実用的ではない。加えて、不織布に極細繊維を用いているため、泥水を濾過すると目詰まりしやすく一度に多量の泥水を処理できない、といった課題も存在する。 Even if the above-described technique is applied to soil decontamination, for example, the filtration filter described in Non-Patent Document 1 adsorbs and decontaminates radioactive cesium dissolved in water. The radioactive cesium adsorbed on can not be decontaminated. Moreover, even if the protective sheet materials described in Patent Documents 1 and 2 are used, the ultrafine fiber nonwoven fabric is expensive, and is not practical because it is an excessive quality as a soil decontamination filter. In addition, since ultrafine fibers are used for the non-woven fabric, there is a problem that if muddy water is filtered, it is easily clogged and a large amount of muddy water cannot be treated at one time.
除染現場では、放射性セシウムを吸着する土壌をフレキシブルコンテナに入れ、仮置き場で保管している。以前は汚染された土壌が外部へ流出しないよう、通水性を有していないフレキシブルコンテナが使用されていた。しかし、中に含まれる落ち葉、草、木などの腐敗性有機物の腐敗が進むと、火災が発生する危険があったため、現在では、火災防止のために、通水性のあるフレキシブルコンテナを使用している。しかしながら、通水性のあるフレキシブルコンテナでは、水と共に放射性セシウムを吸着しているシルトや粘土までもが外部に流れ出てしまうため、仮置き場を再汚染するという新たな問題が生じている。この様な状況下、本発明は、放射性セシウムを吸着するシルト及び粘土を外部に流出させることなく、腐敗性有機物等から脱離するセシウムイオンを吸着するセシウム吸着シートの提供を課題として掲げた。 At the decontamination site, soil that adsorbs radioactive cesium is placed in a flexible container and stored in a temporary storage area. In the past, flexible containers without water permeability were used to prevent contaminated soil from flowing out. However, as perishable organic matter such as fallen leaves, grass, and trees contained in the rot, there was a risk of fire, so now we use flexible containers with water permeability to prevent fire. Yes. However, in a flexible container with water permeability, silt and clay adsorbing radioactive cesium together with water flow out to the outside, which causes a new problem of recontamination of the temporary storage site. Under such circumstances, an object of the present invention is to provide a cesium adsorption sheet that adsorbs cesium ions desorbed from spoilage organic substances and the like without causing silt and clay adsorbing radioactive cesium to flow out.
本発明者は、前記課題を解決するために鋭意研究を重ねた結果、基材となる不織布の少なくとも片面に、発泡状態の塗料を塗布して、前記不織布の厚さ方向に該塗料の一部が浸透した状態で前記塗料を固化させてセシウム吸着シートを製造することにより、断面及び塗料塗布面の細孔の最大ポアサイズ、及び通気量を所定の範囲内に制御でき、この構成により、水からシルト及び粘土を高い分離効率で濾過し、放射性セシウムの吸着率を向上できることを見出し、本発明を完成した。 As a result of intensive research in order to solve the above problems, the present inventor applied a foamed paint to at least one surface of the nonwoven fabric to be a base material, and a part of the paint in the thickness direction of the nonwoven fabric. When the cesium adsorbing sheet is produced by solidifying the paint in a state where the water has permeated, the maximum pore size of the cross-section and the pores on the paint application surface, and the air flow rate can be controlled within a predetermined range. The present inventors completed the present invention by finding that the silt and clay can be filtered with high separation efficiency to improve the adsorption rate of radioactive cesium.
すなわち本発明に係るセシウム吸着シートは、放射性セシウム吸着剤とバインダー樹脂とを含む発泡状態の塗料を不織布の少なくとも片面に塗布し、前記不織布の厚さ方向に該塗料の一部が浸透した状態で前記塗料を固化させて得られ、セシウム吸着シートの断面及び塗料塗布面の表面における細孔の最大ポアサイズが５〜８０μｍであり、ＪＩＳ Ｌ１９１３ ６．８．１のフラジール形法にて測定される通気量が１７０ｃｃ／ｃｍ2・ｓｅｃ以下であることを特徴とする。前記塗料を塗布する際、該塗料を発泡倍率２〜２０倍に起泡することが好ましい。更に、前記塗料が、前記不織布の片面又は両面に塗布されていることが好ましく、セシウム吸着シートに固着する前記放射性セシウム吸着剤の合計量が、乾燥付着量で０．５〜５０ｇ／ｍ2であることが好ましい。また、前記不織布を構成する繊維の繊度が０．８〜３０ｄｔｅｘであり、目付が１０〜１０００ｇ／ｍ2であることが好ましく、より好ましくはセシウム吸着シートの厚さが１０ｍｍ以下である態様である。加えて、前記不織布の内部に、前記塗料が浸透していない層が存在していてもよい。
本発明は更に、前記セシウム吸着シートを用いる泥水用濾過フィルターも包含する。
That is, in the cesium adsorbing sheet according to the present invention, a foamed paint containing a radioactive cesium adsorbent and a binder resin is applied to at least one surface of a nonwoven fabric, and a part of the paint penetrates in the thickness direction of the nonwoven fabric. Aeration obtained by solidifying the paint, having a maximum pore size of 5 to 80 μm on the cross section of the cesium adsorption sheet and the surface of the paint application surface, and measured by the fragile method of JIS L1913 6.8.1 The amount is 170 cc / cm 2 · sec or less. When applying the paint, it is preferable to foam the paint at a foaming ratio of 2 to 20 times. Furthermore, it is preferable that the coating material is applied to one side or both sides of the nonwoven fabric, and the total amount of the radioactive cesium adsorbent fixed to the cesium adsorption sheet is 0.5 to 50 g / m 2 in terms of dry adhesion amount. Preferably there is. Moreover, it is preferable that the fineness of the fiber which comprises the said nonwoven fabric is 0.8-30 dtex, and a fabric weight is 10-1000 g / m < 2 >, More preferably, the thickness of a cesium adsorption sheet is 10 mm or less. . In addition, a layer into which the coating material does not penetrate may be present inside the nonwoven fabric.
The present invention further includes a muddy water filtration filter using the cesium adsorption sheet.
本発明によれば、放射性セシウム吸着剤とバインダー樹脂とを含む発泡状態の塗料を不織布の少なくとも片面に塗布するという一操作で、放射性セシウム吸着剤を不織布に固定することができる上、セシウム吸着シート表面の状態及び通気量もコントロールできる。これにより、本発明のセシウム吸着シートを用いれば、泥水から、水と、シルト及び粘土を高い分離効率で濾過することが可能となり、放射性セシウムの吸着率も従来品に比べて更に高めることができる。 According to the present invention, the radioactive cesium adsorbent can be fixed to the nonwoven fabric by one operation of applying a foamed paint containing the radioactive cesium adsorbent and the binder resin to at least one surface of the nonwoven fabric, and the cesium adsorption sheet. The surface condition and air flow can also be controlled. Thereby, if the cesium adsorption sheet of this invention is used, it will become possible to filter water, silt, and clay from muddy water with high separation efficiency, and the adsorption rate of radioactive cesium can further be raised compared with a conventional product. .
以下、本発明について詳述するが、明細書中、各用語の意味は以下の通りである。
「放射性セシウム」は、セシウム原子の放射性同位体を意味し、主に、セシウム１３４、セシウム１３７を意味する。
「土壌」は、地殻表面の岩石の分解によって生じた無機物、及び、腐敗分解した動埴物を含む、地表に堆積する物質を意味する。
「泥水」は、採取した土壌と水とを含む混合物をいう。
「泥」は、泥水を濾過した後の残渣をいう。
「除染」は、放射性セシウムが付着している汚染土壌から放射性セシウムを分離することを意味する。
Hereinafter, although this invention is explained in full detail, the meaning of each term is as follows in a specification.
“Radioactive cesium” means a radioactive isotope of a cesium atom, and mainly means cesium 134 and cesium 137.
“Soil” means substances deposited on the earth surface, including inorganic substances generated by the decomposition of rocks on the surface of the crust, and rot-decomposed animals.
“Muddy water” refers to a mixture containing collected soil and water.
“Mud” refers to the residue after filtering muddy water.
“Decontamination” means separating radioactive cesium from contaminated soil to which radioactive cesium is attached.
本発明に係るセシウム吸着シートは、放射性セシウム吸着剤とバインダー樹脂とを含む発泡状態の塗料を不織布の少なくとも片面に塗布し、前記不織布の厚さ方向に該塗料の一部が浸透した状態で前記塗料を固化させて得られることを特徴とする。放射性セシウム吸着剤とバインダーとを含む塗料を、発泡した状態で不織布に塗布することにより、（１）放射性セシウム吸着剤を不織布に固定することができ、泥水中（特に、水、シルト及び粘土中）の放射性セシウムを簡便に吸着除去できるといった効果が発揮される。（２）また発泡塗料を塗布する本発明の方法によれば、セシウム吸着シート表面に存在する繊維及び固化した塗料が形成する空隙（以下、細孔と称す）の最大ポアサイズを制御することが可能となる。通常、塗料に不織布を含浸すると、不織布の繊維は塗料中のバインダーの表面張力によって、濡れた繊維同士が引き合い、束になる傾向にあった。そのため、塗料が固化すると、束になった繊維はそのまま固まってしまうため、繊維間空隙として比較的大きな細孔が形成されていた。しかし、不織布に塗料を塗布する際、塗料を発泡状態にしておくと、気泡の存在により塗布された塗料は不織布の厚さ方向に深く浸透できない上、発泡塗料の表面張力は未発泡のものに比べて小さいので、不織布の繊維が束になることなく、塗料を固化することができる。これにより、表面の細孔を小さなまま維持できるため、本発明のセシウム吸着シートを濾材に用いて泥水を濾過すると、水と泥を精度良く分離できるという効果を発揮する。（３）更に、本発明のセシウム吸着シートは（２）で述べたように、セシウム吸着シート表面に存在する細孔が比較的小さい。そのため、セシウム吸着シートに泥水を流し込んだときに、泥が通過しにくく、セシウム吸着シート表面に堆積しやすくなる。この堆積した泥はケーク層となり、このケーク層がフィルターとしての機能を発揮して、更に泥水中のシルトや粘土を捕集する。このように、発泡状態の塗料を不織布表面に塗布することで、一つの操作で多くの問題を一気に解決できるのである。 In the cesium adsorbing sheet according to the present invention, a foamed paint containing a radioactive cesium adsorbent and a binder resin is applied to at least one surface of a nonwoven fabric, and the paint is partially penetrated in the thickness direction of the nonwoven fabric. It is obtained by solidifying a paint. By applying a paint containing a radioactive cesium adsorbent and a binder to the nonwoven fabric in a foamed state, (1) the radioactive cesium adsorbent can be fixed to the nonwoven fabric and muddy water (especially in water, silt and clay) ) Can be easily adsorbed and removed. (2) Further, according to the method of the present invention for applying a foam paint, it is possible to control the maximum pore size of the fibers (hereinafter referred to as pores) formed by the fibers present on the surface of the cesium adsorption sheet and the solidified paint. It becomes. Usually, when a coating material is impregnated with a nonwoven fabric, the fibers of the nonwoven fabric tend to attract each other due to the surface tension of the binder in the coating material to form a bundle. For this reason, when the paint is solidified, the bundled fibers are solidified as they are, so that relatively large pores are formed as interfiber spaces. However, when the paint is applied to the nonwoven fabric, if the paint is kept in a foamed state, the applied paint cannot penetrate deeply in the thickness direction of the nonwoven fabric due to the presence of bubbles, and the surface tension of the foamed paint is not foamed. Since it is smaller than the above, it is possible to solidify the coating material without the fibers of the nonwoven fabric being bundled. Thereby, since the pores on the surface can be kept small, when muddy water is filtered using the cesium adsorbing sheet of the present invention as a filter medium, the effect of separating water and mud with high accuracy is exhibited. (3) Further, as described in (2), the cesium adsorption sheet of the present invention has relatively small pores existing on the surface of the cesium adsorption sheet. Therefore, when muddy water is poured into the cesium adsorbing sheet, the mud is difficult to pass and is easily deposited on the surface of the cesium adsorbing sheet. The accumulated mud becomes a cake layer, and this cake layer functions as a filter, and further collects silt and clay in the mud. Thus, many problems can be solved at once by one operation by applying the foamed paint to the surface of the nonwoven fabric.
＜不織布＞
次に、セシウム吸着シートの基材となる不織布について説明する。セシウム吸着シートに用いる不織布は、長繊維不織布、短繊維不織布のいずれであってもよい。不織布のウェブ形成には、乾式法（カーディング法）、湿式法、スパンボンド法、メルトブロー法等を適宜採用するとよい。ウェブの結合方法も特に限定されるものではなく、例えば、ニードルパンチ法、スパンレース法（水流絡合法）等の機械的絡合法；不織布層に予め低融点繊維を混繊しておき、この低融点繊維の一部又は全部を熱溶融させて、繊維交点を固着する方法（サーマルボンド法）；等の各種結合方法を採用できる。中でも、繊維が丈夫で切れにくいことから、長繊維不織布（特にスパンボンド不織布）が好ましい。
<Nonwoven fabric>
Next, the nonwoven fabric used as the base material of a cesium adsorption sheet is demonstrated. The nonwoven fabric used for the cesium adsorption sheet may be either a long fiber nonwoven fabric or a short fiber nonwoven fabric. For the web formation of the nonwoven fabric, a dry method (carding method), a wet method, a spun bond method, a melt blow method or the like may be appropriately employed. The web bonding method is not particularly limited, for example, a mechanical entanglement method such as a needle punch method, a spunlace method (a water entanglement method), or the like. Various bonding methods such as a method of thermally melting part or all of the melting point fibers and fixing the fiber intersection (thermal bond method) can be employed. Among these, long fiber nonwoven fabrics (especially spunbond nonwoven fabrics) are preferable because the fibers are strong and difficult to cut.
前記不織布を構成する繊維は、例えば、ポリエチレンテレフタレート繊維、ポリトリメチレンテレフタレート繊維、ポリ乳酸繊維等のポリエステル繊維；ポリアリレート繊維；ナイロン６、ナイロン６６などの脂肪族ポリアミド繊維；アラミド繊維等の芳香族ポリアミド繊維；ポリイミド繊維；アクリル繊維；ポリプロピレン繊維、ポリエチレン繊維等のポリオレフィン繊維；ポリウレタン繊維等の合成繊維；ガラス繊維；金属を細く伸ばした金属繊維；綿、麻等の天然繊維；レーヨン等の再生繊維；アセテート繊維等の半合成繊維；等の各種繊維を使用することができる。繊維は、中実繊維であっても中空繊維であってもよく、捲縮を有していても有していなくてもよい。また繊維は芯鞘型、偏心型等の複合繊維であってもよい。これらの繊維は単独で使用してもよく、また複数を混綿して使用してもよい。中でも、入手しやすく、強度にも優れるため、ポリエステル繊維が好ましく、特にポリエチレンテレフタレート繊維が好ましい。 The fibers constituting the nonwoven fabric include, for example, polyester fibers such as polyethylene terephthalate fibers, polytrimethylene terephthalate fibers and polylactic acid fibers; polyarylate fibers; aliphatic polyamide fibers such as nylon 6 and nylon 66; aromatics such as aramid fibers Polyamide fiber; Polyimide fiber; Acrylic fiber; Polyolefin fiber such as polypropylene fiber and polyethylene fiber; Synthetic fiber such as polyurethane fiber; Glass fiber; Metal fiber obtained by extending metal thinly; Natural fiber such as cotton and hemp; Regenerated fiber such as rayon Various fibers such as semi-synthetic fibers such as acetate fibers can be used. The fibers may be solid fibers or hollow fibers and may or may not have crimps. The fiber may be a core-sheath type, an eccentric type or the like. These fibers may be used alone, or a plurality of these fibers may be mixed and used. Among them, polyester fiber is preferable because it is easily available and excellent in strength, and polyethylene terephthalate fiber is particularly preferable.
前記不織布を構成する繊維の繊度は、例えば、０．８〜３０ｄｔｅｘが好ましく、より好ましくは１．０〜１０ｄｔｅｘであり、更に好ましくは１．２〜８ｄｔｅｘである。繊維の繊度が下限値を下回ると、繊維が細すぎて繊維間が密になり、目詰まりし易くなる虞がある。また上限値を上回ると、繊維間が粗になり、濾過性能に劣る可能性があるため好ましくない。 The fineness of the fibers constituting the nonwoven fabric is preferably, for example, 0.8 to 30 dtex, more preferably 1.0 to 10 dtex, and still more preferably 1.2 to 8 dtex. If the fineness of the fibers is below the lower limit, the fibers are too thin and the fibers are dense, and clogging may occur easily. On the other hand, if the upper limit value is exceeded, there is a possibility that the space between fibers becomes rough and the filtration performance may be inferior.
前記不織布の目付は、例えば、１０〜１０００ｇ／ｍ2が好ましく、より好ましくは５０〜７５０ｇ／ｍ2であり、更に好ましくは１００〜５００ｇ／ｍ2であり、特に好ましくは１５０〜３５０ｇ／ｍ2である。目付が下限値を下回ると、繊維量が十分でなくフィルターとして用いるときに濾過効率が低下するといった問題がある。一方上限値を超えると、繊維量が多いため濾過効率は高まるものの、濾過に時間を要してしまい短時間で効率よく濾過を終了することが難しくなる。 Basis weight of the nonwoven fabric, for example, preferably 10 to 1000 g / m 2, more preferably from 50 to 750 g / m 2, more preferably from 100 to 500 g / m 2, particularly preferably 150 to 350 g / m 2 It is. If the basis weight is below the lower limit, the amount of fibers is not sufficient and there is a problem that the filtration efficiency is lowered when used as a filter. On the other hand, if the upper limit is exceeded, the filtration efficiency increases because the amount of fibers is large, but it takes time for the filtration and it is difficult to finish the filtration efficiently in a short time.
前記不織布の厚さは、例えば、０．１〜１０ｍｍが好ましく、より好ましくは０．１〜５ｍｍであり、更に好ましくは０．１〜３ｍｍである。厚さが下限値を下回ると、基材が薄すぎて、フィルターとして用いるときに濾過効率が低下するといった問題がある。一方上限値を超えると、濾過に時間を要してしまい短時間で効率よく濾過を終了することが難しくなる。 The thickness of the nonwoven fabric is preferably 0.1 to 10 mm, more preferably 0.1 to 5 mm, and still more preferably 0.1 to 3 mm. When the thickness is lower than the lower limit, there is a problem that the base material is too thin and the filtration efficiency is lowered when used as a filter. On the other hand, if the upper limit is exceeded, it takes time for filtration, and it is difficult to finish the filtration efficiently in a short time.
＜塗料＞
次に基材に塗布する塗料について説明する。塗料とは、放射性セシウム吸着剤とバインダー樹脂とを含むものであり、発泡状態で基材に塗布する。固形の放射性セシウム吸着剤は、分散媒にほぼ均一に分散されていることが好ましい。
<Paint>
Next, the coating material applied to the substrate will be described. The paint includes a radioactive cesium adsorbent and a binder resin, and is applied to the base material in a foamed state. It is preferable that the solid radioactive cesium adsorbent is dispersed almost uniformly in the dispersion medium.
前記放射性セシウム吸着剤としては、セシウム吸着シートの使用環境に応じて、例えば、フェロシアン化鉄、フェロシアン化カリウム、フェロシアン化アンモニウム等のフェロシアン化物等が挙げられるが、本発明はこれらに限定されるものではない。 Examples of the radioactive cesium adsorbent include ferrocyanides such as iron ferrocyanide, potassium ferrocyanide, and ammonium ferrocyanide, depending on the use environment of the cesium adsorption sheet, but the present invention is not limited thereto. It is not something.
また塗料は、安価であり、且つ、環境に対する負荷が少ないことから、水を分散媒とするエマルジョン系が好ましい。 In addition, since the paint is inexpensive and has a low environmental load, an emulsion system using water as a dispersion medium is preferable.
また、バインダー樹脂としては、通常、不織布の接着用途で用いる樹脂を適宜使用するとよいが、例えば、酢酸ビニル単量体を構成単位に含む酢酸ビニル系バインダー、アクリル酸及びアクリル酸エステルの共重合体であるアクリル系バインダー、合成ゴム系（例えば、ブタジエン−スチレン系、ブタジエン−アクリロニトリル系、クロロプレン系）バインダーが好ましい。中でも、接着強度が高いという利点を有するため、アクリル系バインダーが好ましい。 Moreover, as the binder resin, it is usually appropriate to use a resin that is used for bonding nonwoven fabrics. For example, a vinyl acetate binder containing a vinyl acetate monomer as a constituent unit, a copolymer of acrylic acid and an acrylate ester An acrylic binder and a synthetic rubber binder (for example, butadiene-styrene, butadiene-acrylonitrile, chloroprene) are preferred. Among them, an acrylic binder is preferable because it has an advantage of high adhesive strength.
前記アクリル酸エステルとしては、例えば、アクリル酸メチル、アクリル酸エチル、アクリル酸プロピル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｓｅｃ−ブチル、アクリル酸ｔｅｒｔ−ブチル、アクリル酸２，２−ジメチルプロピル、アクリル酸シクロヘキシル、アクリル酸−２−ｔｅｒｔ−ブチルフェニル、アクリル酸２−ナフチル、アクリル酸フェニル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸プロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｓｅｃ−ブチル、メタクリル酸ｔｅｒｔ−ブチル、メタクリル酸２，２−ジメチルプロピル、メタクリル酸シクロヘキシル、メタクリル酸−２−ｔｅｒｔ−ブチルフェニル、メタクリル酸２−ナフチル、メタクリル酸フェニル等のラジカル重合性単量体が例示できる。 Examples of the acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, and 2,2-dimethyl acrylate. Propyl, cyclohexyl acrylate, acrylate-2-tert-butylphenyl, 2-naphthyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid sec-butyl, tert-butyl methacrylate, 2,2-dimethylpropyl methacrylate, cyclohexyl methacrylate, 2-tert-butylphenyl methacrylate, 2-naphthyl methacrylate, phenyl methacrylate Radically polymerizable monomers can be exemplified a.
前記アクリル系バインダーのガラス転移温度は、−１０〜５０℃が好ましく、より好ましくは０〜４０℃である。 The glass transition temperature of the acrylic binder is preferably −10 to 50 ° C., more preferably 0 to 40 ° C.
放射性セシウム吸着剤の含有量は、塗料１００重量％中、０．１〜９０重量％が好ましく、０．５〜５０重量％がより好ましく、１〜３０重量％が更に好ましい。 The content of the radioactive cesium adsorbent is preferably 0.1 to 90% by weight, more preferably 0.5 to 50% by weight, and still more preferably 1 to 30% by weight in 100% by weight of the coating material.
塗料には、本発明の効果を阻害しない程度で、整泡剤、増粘剤、発泡剤、着色料、防腐剤等の添加物が含まれていてもよい。 The paint may contain additives such as a foam stabilizer, a thickener, a foaming agent, a colorant, and a preservative, as long as the effects of the present invention are not impaired.
＜セシウム吸着シート＞
セシウム吸着シートは前述したように、放射性セシウム吸着剤とバインダー樹脂とを含む発泡状態の塗料を不織布の少なくとも片面に塗布し、前記不織布の厚さ方向に該塗料の一部が浸透した状態で前記塗料を固化させて得られる。すなわち、発泡状態の塗料を用いると、塗料中の気泡が、塗料が不織布の内部奥深くにまで浸透することを遮り、塗料の一部のみが不織布に浸透し、残りは不織布の表面に気泡を形成した状態で固化する。
<Cesium adsorption sheet>
As described above, the cesium adsorption sheet is obtained by applying a foamed paint containing a radioactive cesium adsorbent and a binder resin to at least one surface of the nonwoven fabric, and in a state where a part of the paint penetrates in the thickness direction of the nonwoven fabric. Obtained by solidifying the paint. That is, when foamed paint is used, bubbles in the paint prevent the paint from penetrating deep inside the nonwoven fabric, only a portion of the paint penetrates into the nonwoven fabric, and the rest forms bubbles on the nonwoven fabric surface. Solidify in the state.
本発明のセシウム吸着シートを製造する方法は、不織布の少なくとも片面に、発泡状態の塗料を塗布するものであれば特に限定されるものではない。例えば、前述した塗料を塗布する際、セシウム吸着シートは、該塗料を２〜２０倍に起泡してから不織布に塗布するとよい。発泡倍率は、３〜１５倍がより好ましく、更に好ましくは４〜１０倍であり、特に好ましくは５〜９倍である。発泡倍率を前記範囲内に調整することにより、セシウム吸着シート表面の細孔径を所定の範囲内にコントロールし易くなる。特にセシウム吸着シートの表面における細孔の最大ポアサイズを前記範囲内に調整するには、発泡塗料を５〜９倍に発泡させておくとよい。 The method for producing the cesium adsorbing sheet of the present invention is not particularly limited as long as the foamed paint is applied to at least one surface of the nonwoven fabric. For example, when applying the above-mentioned paint, the cesium adsorption sheet may be applied to the nonwoven fabric after the paint is foamed 2 to 20 times. The expansion ratio is more preferably 3 to 15 times, still more preferably 4 to 10 times, and particularly preferably 5 to 9 times. By adjusting the expansion ratio within the above range, the pore diameter on the surface of the cesium adsorbing sheet can be easily controlled within the predetermined range. In particular, in order to adjust the maximum pore size of the pores on the surface of the cesium adsorbing sheet within the above range, the foamed paint is preferably foamed 5 to 9 times.
塗料を発泡させる方法としては、例えば、物理的に塗料を発泡させる機械発泡や化学発泡等が知られているが、発泡倍率の調整が容易なことや、発泡のタイミングを制御できることから、少なくとも機械発泡を行うことが好ましい。また発泡の条件を考慮して、機械発泡と化学発泡の両発泡法にて塗料を発泡させても構わない。 As a method of foaming the paint, for example, mechanical foaming or chemical foaming that physically foams the paint is known. However, since the foaming ratio can be easily adjusted and the timing of foaming can be controlled, at least mechanical It is preferable to perform foaming. In consideration of foaming conditions, the paint may be foamed by both mechanical foaming and chemical foaming methods.
発泡塗料を不織布に塗布する方法は特に限定されるものではなく、グラビア法、ロータリープリント法等一般的な塗布法を用いるとよい。塗料を塗布するときは、リバースコーター、キスロールコーター、ナイフコーター等の各種設備を用いるとよく、本発明では特にナイフコーターが好ましい。発泡塗料を不織布に塗布するときは、塗料中の気泡をできるだけ壊さないようにする必要がある。 The method for applying the foam coating to the nonwoven fabric is not particularly limited, and a general application method such as a gravure method or a rotary printing method may be used. When applying the paint, various equipment such as a reverse coater, a kiss roll coater, and a knife coater may be used, and a knife coater is particularly preferred in the present invention. When applying foamed paint to a nonwoven fabric, it is necessary to avoid breaking bubbles in the paint as much as possible.
発泡塗料は、不織布の片面又は両面に塗布される。不織布の片面のみに塗料を塗布すると、最大ポアサイズを制御しやすいため好ましい。また、不織布の両面に塗料を塗布すると、不織布内部に塗料が浸透していない層が形成されるため、セシウム吸着シートの透水性が高まるため好ましい。 The foam coating is applied to one side or both sides of the nonwoven fabric. It is preferable to apply the coating only to one side of the nonwoven fabric because the maximum pore size can be easily controlled. Moreover, it is preferable to apply the coating on both surfaces of the nonwoven fabric because a layer in which the coating is not permeated is formed inside the nonwoven fabric, so that the water permeability of the cesium adsorption sheet is increased.
発泡塗料を塗布した後、塗料を固化するために乾燥工程を実施してもよい。乾燥工程では、加熱温度が高すぎると、加熱により放射性セシウム吸着剤（特にプルシアンブルー）が分解する虞がある。そのため、加熱条件下で乾燥工程を実施する場合は、１８０℃以下が好ましく、より好ましくは１２０〜１６０℃であり、更に好ましくは１３０〜１５０℃である。 After applying the foam paint, a drying step may be performed to solidify the paint. In the drying process, if the heating temperature is too high, the radioactive cesium adsorbent (particularly Prussian blue) may be decomposed by heating. Therefore, when implementing a drying process on heating conditions, 180 degrees C or less is preferable, More preferably, it is 120-160 degreeC, More preferably, it is 130-150 degreeC.
このようにして製造されたセシウム吸着シートは、塗料の浸透程度を調整できるため、不織布の内部に、塗料が浸透していない層が存在していることがある。この塗料が浸透していない層の存在によりセシウム吸着シートの透水性が高まるため、泥水により目詰まりし難いセシウム吸着シートが得られる。またセシウム吸着シートの表面に、塗料中の気泡が一部、固化後もそのままの状態で残っていてもよい。 Since the cesium adsorption sheet manufactured in this manner can adjust the degree of penetration of the paint, there may be a layer in which the paint is not penetrated inside the nonwoven fabric. Since the water permeability of the cesium adsorbing sheet is increased by the presence of the layer into which the paint does not penetrate, a cesium adsorbing sheet that is not easily clogged by muddy water is obtained. Further, some of the bubbles in the paint may remain on the surface of the cesium adsorbing sheet as it is after solidification.
このようにして得られたセシウム吸着シートは、表面に比較的小さな細孔を有しているため、水と泥の分離効率を高めたり、堆積した泥によりケーク層を形成することもできる。形成されるセシウム吸着シートの断面及び塗料塗布面の表面における細孔の最大ポアサイズは、５〜８０μｍが好ましく、より好ましくは１０〜７０μｍであり、更に好ましくは１５〜６０μｍである。最大ポアサイズが上限値を超えると、細孔の孔径が大きすぎて、シルトや粘土等の粒径が小さな成分がフィルターを通過してしまい、濾過効率が低下してしまう。また、最大ポアサイズが下限値を下回ると、細孔が小さすぎて、フィルターが目詰まりしやすくなる。なお、細孔の最大ポアサイズは実施例の欄で示す方法により測定できる。 Since the cesium adsorbing sheet thus obtained has relatively small pores on the surface, the separation efficiency of water and mud can be increased, and a cake layer can be formed by the accumulated mud. The maximum pore size of the pores on the cross section of the formed cesium adsorbing sheet and the surface of the coating surface is preferably 5 to 80 μm, more preferably 10 to 70 μm, and still more preferably 15 to 60 μm. When the maximum pore size exceeds the upper limit value, the pore diameter is too large, and components having a small particle size such as silt and clay pass through the filter, resulting in a decrease in filtration efficiency. On the other hand, if the maximum pore size is below the lower limit, the pores are too small and the filter is likely to be clogged. The maximum pore size of the pores can be measured by the method shown in the example column.
また、セシウム吸着シートのＪＩＳ Ｌ１９１３ ６．８．１のフラジール形法にて測定される通気量は、１７０ｃｃ／ｃｍ2・ｓｅｃ以下が好ましく、より好ましくは１６０ｃｃ／ｃｍ2・ｓｅｃ以下であり、更に好ましくは１５５ｃｃ／ｃｍ2・ｓｅｃ以下である。一方、通気量の下限値は特に限定されるものではないが、５０ｃｃ／ｃｍ2・ｓｅｃ以上が好ましく、より好ましくは７０ｃｃ／ｃｍ2・ｓｅｃ以上であり、更に好ましくは１００ｃｃ／ｃｍ2・ｓｅｃ以上である。通気量が前記範囲内であれば、濾過時間と濾過効率のバランスのよいセシウム吸着シートが得られる。 Also, ventilation amount measured by Cesium adsorption sheet of JIS L1913 6.8.1 of Frazier method, is preferably not more than 170cc / cm 2 · sec, more preferably not more than 160cc / cm 2 · sec, further Preferably, it is 155 cc / cm 2 · sec or less. On the other hand, the lower limit value of the air flow rate is not particularly limited, but is preferably 50 cc / cm 2 · sec or more, more preferably 70 cc / cm 2 · sec or more, and further preferably 100 cc / cm 2 · sec or more. It is. When the air flow rate is within the above range, a cesium adsorption sheet having a good balance between filtration time and filtration efficiency can be obtained.
セシウム吸着シートに固着する放射性セシウム吸着剤の合計量は、乾燥付着量で０．５〜５０ｇ／ｍ2が好ましく、より好ましくは２〜４０ｇ／ｍ2であり、更に好ましくは３〜３０ｇ／ｍ2である。放射性セシウム吸着剤は高価なため、放射性セシウム吸着剤の量が上限値を超えると、セシウム吸着シートを安価で製造することが難しくなる。 The total amount of the radioactive cesium adsorbent fixed to the cesium adsorbing sheet is preferably 0.5 to 50 g / m 2 , more preferably 2 to 40 g / m 2 , and still more preferably 3 to 30 g / m 2 in terms of dry adhesion. 2 . Since the radioactive cesium adsorbent is expensive, if the amount of the radioactive cesium adsorbent exceeds the upper limit value, it becomes difficult to produce a cesium adsorbent sheet at low cost.
また、セシウム吸着シートに固着するバインダー樹脂と放射性セシウム吸着剤の重量比（バインダー樹脂：放射性セシウム吸着剤）は、９９：１〜５０：５０が好ましく、より好ましくは９０：１０〜６０：４０であり、更に好ましくは８８：１２〜７５：２５である。放射性セシウム吸着剤の配合比率が高まると、該吸着剤がセシウム吸着シートから剥がれ落ちる虞がある。また、バインダー樹脂の配合比率が高まると、放射性セシウム吸着剤の表面がバインダー樹脂に被覆され外部に露出し難くなるため、放射性セシウム吸着率が低下する虞もある。 In addition, the weight ratio of the binder resin and the radioactive cesium adsorbent fixed to the cesium adsorbing sheet (binder resin: radiocesium adsorbent) is preferably 99: 1 to 50:50, more preferably 90:10 to 60:40. More preferably 88:12 to 75:25. When the mixing ratio of the radioactive cesium adsorbent increases, the adsorbent may be peeled off from the cesium adsorbent sheet. Moreover, since the surface of a radioactive cesium adsorbent will be coat | covered with binder resin and it will become difficult to expose outside when the mixture ratio of binder resin increases, there exists a possibility that a radioactive cesium adsorption rate may fall.
このようにして製造されたセシウム吸着シートの目付は、セシウム吸着シートの用途及び使用環境を考慮して適宜調整するとよいが、例えば、１０〜１０００ｇ／ｍ2が好ましく、より好ましくは３０〜７５０ｇ／ｍ2であり、更に好ましくは５０〜６５０ｇ／ｍ2であり、特に好ましくは７０〜６００ｇ／ｍ2である。目付が下限値を下回ると、繊維量が十分でなくフィルターとして用いるときに濾過効率が低下するといった問題がある。一方上限値を超えると、繊維量が多いため濾過効率は高まるものの、濾過に時間を要してしまい短時間で効率よく濾過を終了することが難しくなる。 The basis weight of the cesium adsorbing sheet thus produced may be appropriately adjusted in consideration of the use and use environment of the cesium adsorbing sheet. For example, 10 to 1000 g / m 2 is preferable, and 30 to 750 g / m is more preferable. m 2 , more preferably 50 to 650 g / m 2 , and particularly preferably 70 to 600 g / m 2 . If the basis weight is below the lower limit, the amount of fibers is not sufficient and there is a problem that the filtration efficiency is lowered when used as a filter. On the other hand, if the upper limit is exceeded, the filtration efficiency increases because the amount of fibers is large, but it takes time for the filtration and it is difficult to finish the filtration efficiently in a short time.
セシウム吸着シートの厚さは、例えば、１０ｍｍ以下が好ましく、より好ましくは８ｍｍ以下であり、更に好ましくは６ｍｍ以下であり、０．１ｍｍ以上が好ましく、より好ましくは０．２ｍｍ以上であり、更に好ましくは０．３ｍｍ以上である。厚さが下限値を下回ると、基材が薄すぎて、フィルターとして用いるときに濾過効率が低下するといった問題がある。一方上限値を超えると、濾過に時間を要してしまい短時間で効率よく濾過を終了することが難しくなる。 The thickness of the cesium adsorption sheet is preferably 10 mm or less, more preferably 8 mm or less, still more preferably 6 mm or less, preferably 0.1 mm or more, more preferably 0.2 mm or more, and still more preferably Is 0.3 mm or more. When the thickness is lower than the lower limit, there is a problem that the base material is too thin and the filtration efficiency is lowered when used as a filter. On the other hand, if the upper limit is exceeded, it takes time for filtration, and it is difficult to finish the filtration efficiently in a short time.
このようにして製造されたセシウム吸着シートは、実施例の欄で詳述する「濾過効率」で９５．５％以上を達成できる。特に、発泡塗料を不織布の片面にのみ塗布したセシウム吸着シートは、最大ポアサイズを制御しやすいため、より高い濾過効率を発揮でき、捕集効率として、例えば、９６％以上を達成できる。 The cesium adsorbing sheet thus produced can achieve 95.5% or more in “filtration efficiency” described in detail in the column of Examples. In particular, a cesium adsorbing sheet in which a foam coating is applied only on one side of a nonwoven fabric can easily control the maximum pore size, and thus can exhibit higher filtration efficiency and can achieve, for example, 96% or more as the collection efficiency.
＜用途＞
本発明に係るセシウム吸着シートは、濾過操作を必要とする除染用濾材として広く用いることができる。本発明のセシウム吸着シートは従来困難であった土壌の除染に好ましく用いることができ、特に泥水用濾過フィルターとして使用するとよい。前記泥水用濾過フィルターとして用いる場合は、セシウム吸着シートを所定の大きさに切断し、例えば、フレキシブルコンテナーの内袋としてセットするとよい。片面塗布のセシウム吸着シートを用いる場合は、塗布面が被濾過流体流入側を向くようにしてセットすることが好ましい。
<Application>
The cesium adsorption sheet according to the present invention can be widely used as a filter material for decontamination requiring filtration operation. The cesium adsorbing sheet of the present invention can be preferably used for soil decontamination, which has been difficult in the past, and is particularly preferably used as a muddy water filtration filter. When used as the muddy water filtration filter, the cesium adsorption sheet may be cut into a predetermined size and set, for example, as an inner bag of a flexible container. In the case of using a cesium adsorbing sheet that is applied on one side, it is preferable to set it so that the application surface faces the fluid to be filtered side.
セシウム吸着シートは、比較的孔径の小さな細孔を有するため泥水を流し込むと、固形成分が堆積し、表面にケーク層を形成する。このケーク層がフィルターの役割を果たし、流し込んだ泥水はゆっくりとセシウム吸着シートを通過する。セシウム吸着シートに固定している放射性セシウム吸着剤は、接触時間が長いほど放射性セシウム吸着率が高まるため、ゆっくりと濾過する程放射性セシウムの吸着効率が向上する。すなわち、本発明のセシウム吸着シートは適度に濾過時間を長くできることからも、放射性セシウムの除染用途に好ましいと言える。 Since the cesium adsorbing sheet has pores with relatively small pore diameters, when muddy water is poured, solid components are deposited and a cake layer is formed on the surface. This cake layer acts as a filter, and the muddy water that has flowed in slowly passes through the cesium adsorption sheet. Since the radioactive cesium adsorbent fixed to the cesium adsorbing sheet has a higher radiocesium adsorption rate as the contact time is longer, the adsorption efficiency of the radioactive cesium is improved as it is slowly filtered. That is, it can be said that the cesium adsorbing sheet of the present invention is preferable for the radioactive cesium decontamination application because the filtration time can be appropriately lengthened.
以下、実施例を挙げて本発明をより具体的に説明するが、本発明はもとより下記実施例によって制限を受けるものではなく、前・後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも勿論可能であり、それらはいずれも本発明の技術的範囲に包含される。 EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.
実施例の欄における測定方法及び評価方法は以下の通りである。
（１）目付；ＪＩＳ Ｌ１９１３ ６．２に準じて測定する。
（２）通気量（ｃｃ／ｃｍ2・ｓ）；ＪＩＳ Ｌ１９１３ ６．８．１（フラジール形法）に準じた。測定機器としては、カトーテック株式会社製「通気性試験機（ＫＥＳ−Ｆ８）」を用いた。
（３）発泡倍率；起泡後の塗料の体積を、起泡前の塗料の体積で除して求めた。
（４）濁度試験（濾過効率・ダスト捕捉量）；
濾過効率の測定は以下の手順で行った。
１．水にＪＩＳ７種のダストを加え攪拌し、ダスト濃度が０．０２５重量％となるように調整して試験水を作製した。
２．作製したセシウム吸着シートを、直径が４２ｍｍとなるように打ち抜き、試験前のセシウム吸着シートの重量Ｗ0を測定した。
３．図１に示す漏斗６に、打ち抜いたセシウム吸着シート７をセットした。また、試験水用の容器１に、作製した試験水２をセットした。該容器に含まれる試験水２は、流水中止まで常に攪拌機３で攪拌していた。
４．流水開始前において、試験水用の容器に含まれる試験水の濁度Ｔ0を測定した。
５．２００ｍｌ／ｍｉｎの流量で試験水を流し（実際には、流量は多少バラつく）、試験水用容器１と漏斗６を繋ぐチューブ５に圧力計４を設置し、常時圧力を計測した。圧力損失が２ｋｇ／ｃｍ2に到達した時点で試験水の流水を中止した。このとき、回収タンク９に含まれる濾液８の濁度Ｔ1を測定した。
６．流水中止後、ダストを保持したままの状態でセシウム吸着シートを、１０５℃の条件下で０．５日間乾燥させた。０．５日間乾燥後の該セシウム吸着シート（ダストを保持した状態）の重量Ｗ1を測定し、捕集されたダスト捕捉量（Ｗ1−Ｗ0）を求めた。
７．濾過効率は、Ｔ1をＴ0で除することにより求めた。
（５）最大ポアサイズ；セシウム吸着シートにおける断面及び塗料塗布面の表面をそれぞれ電子顕微鏡で撮影し、細孔の最大孔径を測定した。電子顕微鏡で撮影するときの倍率は、５０倍（塗料塗布面の表面）、６０倍（断面）とした。
（６）透水係数（ｃｍ／ｓｅｃ）の測定；ＪＩＳ Ａ１２１８−１９９８に準じて測定する。
（７）汚染土濾過試験；
図２に示す金網１２の上に、フィルターとして製造したセシウム吸着シート１０をセットした。泥水投入タンク１１にセシウム濃度７４９６．１６Ｂｑ／ｋｇ、含水比８９．６２％の泥水１６ｋｇ（濁度；測定不能）を上から流し込み、浸み出る濾液１７を漏斗１３を伝わせて回収タンク１４に捕集した。濾過は２１時間行い、一定時間毎に濾液の量を測定した。また、２１時間濾過した後の濾液のセシウム濃度及び濾液の濁度を測定した。また泥水投入タンクの下部には土砂１６が堆積していた。
（８）セシウム吸着率；
セシウム濃度１０００ｐｐｂに調整した試験液２００ｍｌ（溶媒：水）を容器に入れ、ここへ製造したセシウム吸着シートを５４ｃｍ2にカットしたセシウム吸着シートを投入した。マグネチックスターラーで攪拌しながら、室温下で２４時間吸着操作を行った後、試験液のセシウム濃度Ｃ1（ｐｐｂ）を測定した。セシウム吸着率（％）は、｛Ｃ1（ｐｐｂ）／１０００（ｐｐｂ）｝×１００により求めた。
The measurement method and evaluation method in the column of Examples are as follows.
(1) Weight per unit area: Measured according to JIS L1913 6.2.
(2) Aeration rate (cc / cm 2 · s): Conforms to JIS L1913 6.8.1 (Fragile form method). As a measuring instrument, “Breathability Tester (KES-F8)” manufactured by Kato Tech Co., Ltd. was used.
(3) Foaming ratio: It was determined by dividing the volume of the paint after foaming by the volume of the paint before foaming.
(4) Turbidity test (filtration efficiency, dust trapping amount);
The filtration efficiency was measured according to the following procedure.
1. Test water was prepared by adding JIS 7 types of dust to water and stirring to adjust the dust concentration to 0.025 wt%.
2. The produced cesium adsorption sheet was punched out to have a diameter of 42 mm, and the weight W 0 of the cesium adsorption sheet before the test was measured.
3. The punched cesium adsorption sheet 7 was set in the funnel 6 shown in FIG. Moreover, the produced test water 2 was set in the container 1 for test water. The test water 2 contained in the container was constantly stirred by the stirrer 3 until the running water was stopped.
4). Prior to the start of running water, the turbidity T 0 of the test water contained in the test water container was measured.
5. Test water was flowed at a flow rate of 200 ml / min (actually, the flow rate varied somewhat), and a pressure gauge 4 was installed on the tube 5 connecting the test water container 1 and the funnel 6 to constantly measure the pressure. When the pressure loss reached 2 kg / cm 2 , the test water flow was stopped. At this time, the turbidity T 1 of the filtrate 8 contained in the collection tank 9 was measured.
6). After stopping running water, the cesium adsorption sheet was dried for 0.5 days under the condition of 105 ° C. while the dust was retained. The weight W 1 of the cesium adsorbing sheet (in a state where dust was held) after drying for 0.5 days was measured, and the amount of collected dust (W 1 -W 0 ) was determined.
7). Filtration efficiency was determined by dividing T 1 by T 0 .
(5) Maximum pore size: The cross section of the cesium adsorbing sheet and the surface of the paint application surface were each photographed with an electron microscope, and the maximum pore diameter was measured. The magnification when photographing with an electron microscope was 50 times (surface of the coating surface) and 60 times (cross section).
(6) Measurement of hydraulic conductivity (cm / sec); measured according to JIS A1218-1998.
(7) Contaminated soil filtration test;
The cesium adsorption sheet 10 manufactured as a filter was set on the wire mesh 12 shown in FIG. Pour 16 kg of muddy water (turbidity; impossible to measure) with a cesium concentration of 7496.16 Bq / kg and a water content of 89.62% into the muddy water charging tank 11 from above, and the filtrate 17 that oozes through the funnel 13 to the recovery tank 14 I collected it. Filtration was performed for 21 hours, and the amount of the filtrate was measured at regular intervals. Moreover, the cesium density | concentration of the filtrate after filtering for 21 hours, and the turbidity of the filtrate were measured. In addition, earth and sand 16 was accumulated at the bottom of the muddy water charging tank.
(8) Cesium adsorption rate;
200 ml of a test solution adjusted to a cesium concentration of 1000 ppb (solvent: water) was placed in a container, and a cesium adsorption sheet prepared by cutting the cesium adsorption sheet produced here into 54 cm 2 was introduced. While stirring with a magnetic stirrer, an adsorption operation was performed at room temperature for 24 hours, and then the cesium concentration C 1 (ppb) of the test solution was measured. The cesium adsorption rate (%) was determined by {C 1 (ppb) / 1000 (ppb)} × 100.
実施例１
水を分散媒とするアクリルバインダーに、発泡剤、整泡剤、増粘剤、及びフェロシアン化鉄（プルシアンブルー）を混合して塗料を作製した。この塗料を機械発泡にて発泡倍率７倍にまで発泡させて発泡塗料とした。得られた発泡塗料を、ポリエステル製スパンボンド不織布（東洋紡社製「Ｖ４１３１Ｎ」、繊度３ｄｔｅｘ、目付１５０ｇ／ｍ2）に、ナイフコーターにて該スパンボンド不織布の片面にのみ、フェロシアン化鉄が乾燥付着量目付で１０ｇ／ｍ2となるよう調整して塗布した。得られたセシウム吸着シートの重量は２００ｇ／ｍ2であり、セシウム吸着シートに固着するアクリル系バインダーとフェロシアン化鉄の重量比は５：１であった。このセシウム吸着シートの物性を測定したところ、表に示す結果が得られた。なお、最大ポアサイズの測定で使用した、セシウム吸着シートの断面及び表面を電子顕微鏡で撮影したＳＥＭ画像を図３に示す。
更に製造したセシウム吸着シートを用いて、汚染土濾過試験を行った。結果を表に示す。表から明らかなように、試験開始から２１時間後における濾液の捕集量は３６０ｍｌであった。また濾液中の放射線量は９．２Ｂｑ／ｋｇとなり、上水道基準（１０Ｂｑ／ｋｇ未満）を上回るものであった。また、濁度は１０．２ＮＴＵと、濁りは遊泳用プール水質基準（５ＮＴＵ以下）程度にまで大きく改善された。
また得られたセシウム吸着シートを用いてセシウム吸着試験を行った。
Example 1
A paint was prepared by mixing a foaming agent, a foam stabilizer, a thickener, and iron ferrocyanide (Prussian blue) with an acrylic binder using water as a dispersion medium. This paint was foamed by mechanical foaming to a foaming ratio of 7 times to obtain a foamed paint. The obtained foamed paint is dried on a polyester spunbond nonwoven fabric (“V4131N” manufactured by Toyobo Co., Ltd., fineness 3 dtex, basis weight 150 g / m 2 ), and only on one side of the spunbond nonwoven fabric by a knife coater. The coating weight was adjusted to 10 g / m 2 and applied. The weight of the obtained cesium adsorption sheet was 200 g / m 2 , and the weight ratio of the acrylic binder fixed to the cesium adsorption sheet and iron ferrocyanide was 5: 1. When the physical properties of this cesium adsorption sheet were measured, the results shown in the table were obtained. In addition, the SEM image which image | photographed the cross section and surface of the cesium adsorption sheet used with the measurement of the maximum pore size with the electron microscope is shown in FIG.
Furthermore, the contaminated soil filtration test was done using the manufactured cesium adsorption sheet. The results are shown in the table. As is apparent from the table, the collected amount of the filtrate 21 hours after the start of the test was 360 ml. The radiation dose in the filtrate was 9.2 Bq / kg, which exceeded the water supply standard (less than 10 Bq / kg). The turbidity was 10.2 NTU, and the turbidity was greatly improved to the swimming pool water quality standard (5 NTU or less).
Moreover, the cesium adsorption | suction test was done using the obtained cesium adsorption sheet.
実施例２
実施例１と同じ発泡塗料を、ポリエステル製スパンボンド不織布（東洋紡社製「Ｖ４１３１Ｎ」、繊度３ｄｔｅｘ、目付１５０ｇ／ｍ2）に、ナイフコーターにて該スパンボンド不織布の両面に、フェロシアン化鉄が乾燥付着量で１０ｇ／ｍ2となるよう調整して塗布した。得られたセシウム吸着シートの重量は２００ｇ／ｍ2であり、セシウム吸着シートに固着するアクリル系バインダーとフェロシアン化鉄の重量比は５：１であった。このセシウム吸着シートの物性を測定したところ、表に示す結果が得られた。なお、最大ポアサイズの測定で使用した、セシウム吸着シートの断面及び表面を電子顕微鏡で撮影したＳＥＭ画像を図３に示す。
更に製造したセシウム吸着シートを用いて、汚染土濾過試験を行った。結果を表に示す。表から明らかなように、試験開始から２１時間後における濾液の捕集量は４６７ｍｌであった。また、濁度は１７ＮＴＵと、実施例１と同様に濁りはかなり改善された。
また得られたセシウム吸着シートを用いてセシウム吸着試験を行った。
Example 2
The same foamed paint as in Example 1 was applied to a polyester spunbonded nonwoven fabric (“V4131N” manufactured by Toyobo Co., Ltd., fineness 3 dtex, basis weight 150 g / m 2 ), and ferrocyanide iron on both sides of the spunbonded nonwoven fabric with a knife coater. The dry adhesion amount was adjusted to 10 g / m 2 and applied. The weight of the obtained cesium adsorption sheet was 200 g / m 2 , and the weight ratio of the acrylic binder fixed to the cesium adsorption sheet and iron ferrocyanide was 5: 1. When the physical properties of this cesium adsorption sheet were measured, the results shown in the table were obtained. In addition, the SEM image which image | photographed the cross section and surface of the cesium adsorption sheet used with the measurement of the maximum pore size with the electron microscope is shown in FIG.
Furthermore, the contaminated soil filtration test was done using the manufactured cesium adsorption sheet. The results are shown in the table. As is apparent from the table, the amount of filtrate collected after 21 hours from the start of the test was 467 ml. Further, the turbidity was 17 NTU, and the turbidity was considerably improved as in Example 1.
Moreover, the cesium adsorption | suction test was done using the obtained cesium adsorption sheet.
実施例３
実施例１と同じ発泡塗料を、ポリエステル製スパンボンド不織布（東洋紡社製「９４５ＲＨＢ」、繊度５．５ｄｔｅｘ、目付４５０ｇ／ｍ2）に、ナイフコーターにて該スパンボンド不織布の片面にのみ、フェロシアン化鉄が乾燥付着量で１０ｇ／ｍ2となるよう調整して塗布した。得られたセシウム吸着シートの重量は５１０ｇ／ｍ2であり、セシウム吸着シートに固着するアクリル系バインダーとフェロシアン化鉄の重量比は５：１であった。このセシウム吸着シートの物性を測定したところ、表に示す結果が得られた。なお、最大ポアサイズの測定で使用した、セシウム吸着シートの断面及び表面を電子顕微鏡で撮影したＳＥＭ画像を図３に示す。
更に製造したセシウム吸着シートを用いて、汚染土濾過試験を行った。結果を表に示す。表から明らかなように、試験開始から２１時間後における濾液の捕集量は３４２ｍｌであった。また濁度は９．３５ＮＴＵと、他の実施例と同様に濁りはかなり改善された。
また得られたセシウム吸着シートを用いてセシウム吸着試験を行った。
Example 3
The same foamed paint as in Example 1 was applied to a polyester spunbonded nonwoven fabric (“945RHB” manufactured by Toyobo Co., Ltd., fineness 5.5 dtex, basis weight 450 g / m 2 ) on a single side of the spunbonded nonwoven fabric using a knife coater. It was applied so that the iron oxide was adjusted to a dry adhesion amount of 10 g / m 2 . The weight of the obtained cesium adsorption sheet was 510 g / m 2 , and the weight ratio of the acrylic binder fixed to the cesium adsorption sheet and ferric ferrocyanide was 5: 1. When the physical properties of this cesium adsorption sheet were measured, the results shown in the table were obtained. In addition, the SEM image which image | photographed the cross section and surface of the cesium adsorption sheet used with the measurement of the maximum pore size with the electron microscope is shown in FIG.
Furthermore, the contaminated soil filtration test was done using the manufactured cesium adsorption sheet. The results are shown in the table. As is apparent from the table, the amount of filtrate collected after 21 hours from the start of the test was 342 ml. The turbidity was 9.35 NTU, and the turbidity was considerably improved as in the other examples.
Moreover, the cesium adsorption | suction test was done using the obtained cesium adsorption sheet.
比較例１
水を分散媒とするアクリルバインダーに、フェロシアン化鉄を混合して塗料を作製した。ポリエステル製スパンボンド不織布（東洋紡社製「Ｖ４１３１Ｎ」、繊度３ｄｔｅｘ、目付１５０ｇ／ｍ2）を該塗料に浸透させ、フェロシアン化鉄が乾燥付着量で１０ｇ／ｍ2となるようディッピング加工した。得られたセシウム吸着シートの重量は２１０ｇ／ｍ2であった。このセシウム吸着シートの物性を測定したところ、表に示す結果が得られた。なお、最大ポアサイズの測定で使用した、セシウム吸着シートの断面及び表面を電子顕微鏡で撮影したＳＥＭ画像を図３に示す。
更に製造したセシウム吸着シートを用いて、汚染土濾過試験を行った。結果を表に示す。表から明らかなように、試験開始から２１時間後における水の捕集量は５２２ｍｌであった。また濾液中の放射線量は１１．６７Ｂｑ／ｋｇとなり、実施例１〜３と比べると放射線量は多くなった。また濁度は１７０ＮＴＵと、実施例のものに比べ、濁度の改善度合は不十分であった。
また得られたセシウム吸着シートを用いてセシウム吸着試験を行った。
Comparative Example 1
A paint was prepared by mixing ferric ferrocyanide with an acrylic binder using water as a dispersion medium. A polyester spunbonded nonwoven fabric (“V4131N” manufactured by Toyobo Co., Ltd., fineness of 3 dtex, basis weight of 150 g / m 2 ) was permeated into the paint, and dipped so that ferric ferrocyanide had a dry adhesion amount of 10 g / m 2 . The weight of the obtained cesium adsorption sheet was 210 g / m 2 . When the physical properties of this cesium adsorption sheet were measured, the results shown in the table were obtained. In addition, the SEM image which image | photographed the cross section and surface of the cesium adsorption sheet used with the measurement of the maximum pore size with the electron microscope is shown in FIG.
Furthermore, the contaminated soil filtration test was done using the manufactured cesium adsorption sheet. The results are shown in the table. As is apparent from the table, the amount of water collected after 21 hours from the start of the test was 522 ml. Moreover, the radiation dose in a filtrate was set to 11.67 Bq / kg, and the radiation dose increased compared with Examples 1-3. Further, the turbidity was 170 NTU, which was insufficient for improving the turbidity compared to the examples.
Moreover, the cesium adsorption | suction test was done using the obtained cesium adsorption sheet.
比較例２
発泡塗料にフェロシアン化鉄を混合しないこと以外は、実施例１と同様の方法でセシウム吸着シートを製造した。試験開始から２１時間後における水の捕集量は実施例１と同程度であったが、フェロシアン化鉄が含まれていないため、濾液中のセシウム濃度及びセシウム吸着率の値は悪化した。
Comparative Example 2
A cesium adsorbing sheet was produced in the same manner as in Example 1 except that iron ferrocyanide was not mixed with the foamed paint. The amount of water collected after 21 hours from the start of the test was about the same as that in Example 1. However, since ferric ferrocyanide was not included, the values of cesium concentration and cesium adsorption rate in the filtrate deteriorated.
比較例３
市販の小型土のうを用いて、他の例と同様に汚染土試験を行った。浸み出してきた水の放射線量は７７．５７Ｂｑ／ｋｇとなり、放射線量は極めて多くなった。また濁度は３４７ＮＴＵと、濁度の改善度合は満足のいくものではなかった。
Comparative Example 3
A contaminated soil test was conducted in the same manner as the other examples using a commercially available small sandbag. The radiation dose of the leaching water was 77.57 Bq / kg, and the radiation dose was extremely increased. The turbidity was 347 NTU, and the improvement in turbidity was not satisfactory.
このように、放射性セシウム吸着剤を含む発泡状態の塗料を不織布に塗布することにより、セシウム吸着シートの最大ポアサイズ、通気量、濾過効率等の細かな条件を管理することができたため、効率良く、放射性物質に汚染されたシルトや粘土を捕集することが可能となった。また濾過後の浸み出し水は、放射線含量の少ないものであった。 In this way, by applying a foamed paint containing a radioactive cesium adsorbent to the nonwoven fabric, it was possible to manage fine conditions such as the maximum pore size of the cesium adsorption sheet, the air flow rate, the filtration efficiency, etc. It became possible to collect silt and clay contaminated with radioactive materials. Further, the leached water after filtration had a low radiation content.
１；試験水用容器、２；試験水、３；攪拌機、４；圧力計、５；チューブ、６；漏斗、７；セシウム吸着シート、８；濾液、９；回収タンク、１０；セシウム吸着シート、１１；泥水投入タンク、１２；金網、１３；漏斗、１４；回収タンク、１５；泥水、１６；土砂、１７；濾液、１８；泥水投入方向 DESCRIPTION OF SYMBOLS 1; Test water container, 2; Test water, 3; Stirrer, 4; Pressure gauge, 5; Tube, 6: Funnel, 7; Cesium adsorption sheet, 8: Filtrate, 9; Collection tank, 10: Cesium adsorption sheet, 11; Muddy water charging tank, 12; Wire net, 13; Funnel, 14; Recovery tank, 15; Muddy water, 16; Earth and sand, 17; Filtrate, 18;
Claims (8)
セシウム吸着シートの断面及び塗料塗布面の表面における細孔の最大ポアサイズが５〜８０μｍであり、ＪＩＳ Ｌ１９１３ ６．８．１のフラジール形法にて測定される通気量が１７０ｃｃ／ｃｍ2・ｓｅｃ以下であることを特徴とするセシウム吸着シート。 A foamed paint containing a radioactive cesium adsorbent and a binder resin is applied to at least one surface of the nonwoven fabric, and is obtained by solidifying the paint in a state in which a part of the paint penetrates in the thickness direction of the nonwoven fabric,
The maximum pore size in the cross section of the cesium adsorbing sheet and the surface of the paint application surface is 5 to 80 μm, and the air flow rate measured by the fragile method of JIS L1913 6.8.1 is 170 cc / cm 2 · sec or less A cesium adsorbing sheet characterized by the above.
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| JP2016163873A (en) * | 2015-02-27 | 2016-09-08 | 東洋クロス株式会社 | Strontium adsorption sheet |
| JP2018038953A (en) * | 2016-09-07 | 2018-03-15 | 東洋紡株式会社 | Anion adsorption sheet |
| KR20190063586A (en) * | 2017-11-30 | 2019-06-10 | (주)크린앤사이언스 | Media for absorbing radioactivity material and manucacturing method thereof |
| JP2021070028A (en) * | 2021-01-04 | 2021-05-06 | 東洋紡株式会社 | Anion adsorption sheet |
| JP7490453B2 (en) | 2020-05-14 | 2024-05-27 | 三菱マテリアル電子化成株式会社 | Oil-water separation filter and its manufacturing method |
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| JP2016163873A (en) * | 2015-02-27 | 2016-09-08 | 東洋クロス株式会社 | Strontium adsorption sheet |
| JP2018038953A (en) * | 2016-09-07 | 2018-03-15 | 東洋紡株式会社 | Anion adsorption sheet |
| JP7144917B2 (en) | 2016-09-07 | 2022-09-30 | 東洋紡株式会社 | Anion adsorption sheet |
| KR20190063586A (en) * | 2017-11-30 | 2019-06-10 | (주)크린앤사이언스 | Media for absorbing radioactivity material and manucacturing method thereof |
| KR102015795B1 (en) | 2017-11-30 | 2019-08-29 | (주)크린앤사이언스 | Media for absorbing radioactivity material and manucacturing method thereof |
| JP7490453B2 (en) | 2020-05-14 | 2024-05-27 | 三菱マテリアル電子化成株式会社 | Oil-water separation filter and its manufacturing method |
| JP2021070028A (en) * | 2021-01-04 | 2021-05-06 | 東洋紡株式会社 | Anion adsorption sheet |
| JP7163978B2 (en) | 2021-01-04 | 2022-11-01 | 東洋紡株式会社 | Anion adsorption sheet |
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