JPS5860299A - Composit material for x-ray shielding - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 本発明は薄くても実用的なＸ線遮へい性能を有するＸ線
遮へい用複合材料に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite material for X-ray shielding that has practical X-ray shielding performance even though it is thin.

従来、Ｘ線遮へい用のシート状材料としては高分子物質
中に鉛または鉛化合物の粉末を練り込んだものが知られ
ていて、〃コがる素材からなるｘａ防護衣、防護エプロ
ンなどがすでに市販されている。しかしながら、かかる
鉛金属、鉛化合物の微粉末は樹脂中に配合できる量が少
なく、最大限混合したとして比重約ｉ５程度の配合が可
能であるにすき′ない。これ以上配合量を増すと、もは
や樹脂はその性質を失ない、もろくて実用的でなくなる
。しかも、この最大値混合したシートでさえ。Conventionally, sheet-like materials for X-ray shielding have been known as materials in which lead or lead compound powder is kneaded into polymeric substances, and xa protective clothing and protective aprons made of kogaru materials are already available. It is commercially available. However, the amount of such fine powder of lead metal or lead compound that can be blended into the resin is small, and even if mixed to the maximum, it would be impossible to blend the powder with a specific gravity of about i5. If the amount is increased beyond this point, the resin no longer loses its properties and becomes brittle and impractical. And even this maximum mixed sheet.

厚みを０５−と薄くするとＪ工ｓ　＋　ｚ４５ｏ１で測
定される鉛当量は０．０８と低いＸ線遮へい性しか示さ
ない。その上かかる鉛微粉末は人体に対して有毒性を有
するものであり、粉塵により作業環境が汚染され易くま
たこの種の汚染は製造を続ける以上完全に防止できない
という致命的欠点がある。When the thickness is reduced to 0.5 -, the lead equivalent measured by J.S.+Z45O1 is 0.08, which shows only a low X-ray shielding property. Moreover, such fine lead powder is toxic to the human body, and the work environment is easily contaminated by the dust, and this type of contamination cannot be completely prevented as long as manufacturing continues, which is a fatal drawback.

また遮音性にすぐれた複合材料として直径１００μ以上
通常２００〜５００μの鉛金属短繊維を用いたものがあ
るが、かかる短繊維は上配粉゛末に比して配合量を著し
く増大せしめることができ、最大比重５，５まで練り込
める。しかし、かかる短繊維からなる複合材料はＸ線を
照射してレントゲン写真をとってみるとＸ線透過による
ピンホールが顕著に認められ、Ｘ、１１遮へい用途への
材料としては致命的な欠点を有するものである。In addition, there are composite materials with excellent sound insulation properties that use short lead metal fibers with a diameter of 100μ or more and usually 200 to 500μ, but the amount of such short fibers may be significantly increased compared to the upper powder. It can be kneaded up to a maximum specific gravity of 5.5. However, when a composite material made of such short fibers is irradiated with X-rays and an X-ray photograph is taken, pinholes due to X-ray transmission are clearly observed, which is a fatal drawback as a material for X, 11 shielding applications. It is something that you have.

本発明者らはかかる従来欠点に鑑み、Ｘ線遮へい性能が
更に高くかつ樹脂の性能をも充券に発揮する複合材料に
ついて検討したところ、特定な直径を有する繊維がかか
る要求を完全に満足する挙動を示すことを究明し本発明
を完成するに至ったものである。In view of these conventional drawbacks, the present inventors investigated composite materials that have even higher X-ray shielding performance and also exhibit the performance of resin in ticket-filling, and found that fibers with a specific diameter completely satisfied these requirements. We have completed the present invention by investigating that this behavior is observed.

すなわち本発明は合成樹脂に鉛金属繊維を配合してなる
複合材料において、該短繊維の直径が６０μ以下であり
、かつ比重が４．０以上であるＸ線遮へい用複合材料に
関する。That is, the present invention relates to a composite material for X-ray shielding made of a synthetic resin mixed with lead metal fibers, in which the short fibers have a diameter of 60 μm or less and a specific gravity of 4.0 or more.

本発明でいう鉛金属とは鉛金属単体あるいはこれにビス
マス、カドミウム、アンチモン、錫、銀。The lead metal referred to in the present invention includes lead metal itself or bismuth, cadmium, antimony, tin, and silver.

ヒ素、カルシウム、亜鉛など通常の合金成分を含むもの
があげられる。鉛成分は多い程、Ｘ線遮へい性能の点か
ら好ましいが１通常鉛成分６０重量％以上のものが適用
される。Examples include those containing common alloy components such as arsenic, calcium, and zinc. The higher the lead content, the better from the point of view of X-ray shielding performance; however, a lead content of 60% by weight or more is usually used.

かかる鉛金属は適宜の方法、たとえば鉛板から繊維を削
り出す方法、電気化学的に鉛繊維を電析。Such lead metal can be obtained by an appropriate method, for example, by cutting fibers from a lead plate, or by electrochemically depositing lead fibers.

成長させる方法、溶融紡糸法などによ多繊維化され得る
が、溶融紡糸法が合理的であり好ましく採用される。溶
融紡糸法によって本発明で採用する如き極細繊維を製造
することは鉛金属の酸化等に基づく、工程上の欠点のた
め困難視され、実用的な繊維は製造されていなかったも
のである。従って極細鉛繊維の樹脂との挙動が粉末や太
径の繊維と異なることは未知であったものであり１本発
明によって初めて明らかにされる事実である。The fibers can be made into multiple fibers by a growing method, a melt spinning method, etc., but the melt spinning method is rational and preferably employed. Producing ultrafine fibers as employed in the present invention by melt spinning is considered difficult due to process defects such as oxidation of lead metal, and no practical fibers have been produced. Therefore, it was unknown that the behavior of ultrafine lead fibers with resin is different from that of powder or large diameter fibers, and this is a fact that will be clarified for the first time by the present invention.

すなわち本発明で適用される鉛金属繊維はいかなる方法
で製造されてもよいが１重要なことは。That is, the lead metal fibers used in the present invention may be manufactured by any method, but one important point is as follows.

その直径が６０μ以下好ましくは５０μ以下、特に６０
〜４０μの極細繊維であることである。Its diameter is 60μ or less, preferably 50μ or less, especially 60μ
The fibers are ultrafine fibers with a diameter of ~40μ.

種々の材料のＸ線遮へい能を比較する上で鉛当量がよく
使用される。鉛当量とは「Ｘ線の遮へい能力がそれに等
価な鉛板の厚さ」で表わしたものであり、鉛当量の大き
いもの＃１ど遮へい能は優れるＯ 優れた遮へい能を得るためには、材料を高比重化し、か
つＸ線吸収素材（鉛金属短繊維）が均一に分散した。均
質な材料とし、鉛当量値を大きくする必要がある。さら
に、このようにして鉛当量値を高くしても１例えばレン
トゲン写真で観測して０局所的にＸ線の透過したピンホ
ール欠点が認められれば、ｘａ遮へい材料としては致命
的欠点を有することになるから、ピンホールのないこと
が必要である。Lead equivalent is often used to compare the X-ray shielding ability of various materials. Lead equivalent is expressed as "the thickness of the lead plate whose X-ray shielding ability is equivalent to that", and the shielding ability is excellent for those with a large lead equivalent #1. In order to obtain excellent shielding ability, The material has a high specific gravity, and the X-ray absorbing material (lead metal short fibers) is uniformly dispersed. It is necessary to use a homogeneous material and to increase the lead equivalent value. Furthermore, even if the lead equivalent value is increased in this way, if a local pinhole defect through which X-rays are transmitted is observed, for example, when observed with an X-ray photograph, it will have a fatal defect as an xa shielding material. Therefore, it is necessary that there be no pinholes.

本発明で用いる極細鉛繊維は樹脂との均一分散性に優れ
、かつ配合できる量の点でも著しく多量であり、しかも
多量に配合しても、樹脂の性質が失なわれないという極
めて好適な特徴を有する。The ultrafine lead fiber used in the present invention has excellent uniform dispersibility with the resin, and can be blended in a significantly large amount, and even when blended in a large amount, the properties of the resin are not lost, which is an extremely favorable feature. has.

この極細繊維の直径が３０μより著しく細くなると、後
で述べる短繊維化の工程で、外力にｒ−リ−微粉末化し
やすく、また混練り過程などの間に細分化し、配合量が
増大せず、ひいてはＸ線遮へい性に悪影響を及ばずので
、好ましくない。また直径が６０μを越えると、太もの
繊維の傾向を示し。If the diameter of these ultrafine fibers becomes significantly thinner than 30μ, they will be easily turned into fine powder by external force during the shortening process described later, and will also become finely divided during the kneading process, so that the amount of blended fibers will not increase. This is not preferable because it does not adversely affect the X-ray shielding properties. Moreover, when the diameter exceeds 60μ, the fibers tend to be thick.

均質分散性が低下し２局所的にＸ線を透過するピンホー
ルが多数発生する。かかる繊維を樹脂に配合するには短
繊維の形で適用されるが、この短繊維の繊維長が長すぎ
ると、混練り過程で、繊維どおしの絡み合いが起抄やす
く、更には塊状になるため、均一分散性を著しく低下す
る。本発明の短繊維としては好ましくは繊維長（Ｉ！）
と繊維直径（（ｉ）の比（ｌ！／’１１）が５．０以上
であり、かつ長くても繊維長が５ＫＩＩＱ１以下好まし
くは２圓以下の短繊維が好適である。The homogeneous dispersibility is reduced and many pinholes that locally transmit X-rays are generated. When such fibers are blended into resin, they are applied in the form of short fibers, but if the fiber length of these short fibers is too long, the fibers are likely to become entangled during the kneading process, and furthermore, they may form into lumps. As a result, uniform dispersibility is significantly reduced. The short fibers of the present invention preferably have a fiber length (I!)
and fiber diameter ((i) (l!/'11) is 5.0 or more, and the fiber length is preferably 5KIIQ1 or less, preferably 2 circles or less).

この鉛金属短繊維は次いで合成樹脂と混合されるが、か
かる合成樹脂としては通常複合材料に採用される熱可塑
性樹脂ならびに熱硬化性ゝ樹脂が適用されうる。The lead metal short fibers are then mixed with a synthetic resin, and thermoplastic resins and thermosetting resins that are commonly used in composite materials can be used as the synthetic resin.

熱硬化性樹脂としてはたとえばエポキシ系樹脂。An example of thermosetting resin is epoxy resin.

フェノール系樹脂、不飽和ポリエステル系樹脂。Phenolic resin, unsaturated polyester resin.

ポリイミド系樹脂などがあけられるが、これらに限定す
る必要はない。また必要に応じてかかる樹脂中に架橋剤
や反応開始剤ならびに各種添加剤を配合することができ
る。Polyimide resin etc. can be used, but there is no need to limit it to these. Further, a crosslinking agent, a reaction initiator, and various additives can be blended into the resin as necessary.

熱可塑性樹脂としてはポリ塩化ビニル系樹脂。The thermoplastic resin is polyvinyl chloride resin.

ポリオレフィン系樹脂、ポリアミド系樹脂、ポリエステ
ル系樹脂などをあげることができる。かがる樹脂として
は必要に応じて更に他の樹脂を用いることも可能である
。また可塑剤や増量剤、熱安定剤、難燃剤、顔料などの
添加剤を樹脂中に配合することもできる。Examples include polyolefin resins, polyamide resins, polyester resins, and the like. It is also possible to use other resins as the overcasting resin, if necessary. Additionally, additives such as plasticizers, fillers, heat stabilizers, flame retardants, and pigments can also be blended into the resin.

本発明の鉛金属短繊維と樹脂とからなる複合材料は比重
が４．０以上、さらには４．５以上と高比重であし、か
つ鉛金属短繊維が均一に分散して、均質性に優れたもの
である。その結果ＪＩＢ　Ｚ−４５０１に基づいて測定
される鉛当量は従来の粉末配合物や大径繊維配合物に比
べると著しく高く、かつＸ線の透過するピンホール欠点
がなく、優れたＸ線遮へい性能を発揮することができる
。The composite material made of lead metal short fibers and resin of the present invention has a high specific gravity of 4.0 or more, even 4.5 or more, and has excellent homogeneity because the lead metal short fibers are uniformly dispersed. It is something that As a result, the lead equivalent measured based on JIB Z-4501 is significantly higher than that of conventional powder formulations or large diameter fiber formulations, and there are no pinhole defects through which X-rays can pass, resulting in excellent X-ray shielding performance. can demonstrate.

特に熱可塑性樹脂からなる複合材料の場合、厚みを０．
５　ｍｍ以下と薄いシート状に加工しても、十分に実用
的なＸ線遮へい能を有するために、柔軟で取り扱い易い
特徴が生かされ、用途展開を図るＬ二で極めて自由度が
高い利点を有する。本発明の一例であるシートは例えば
次のような方法により製造できるが、これに限ったもの
ではない。In particular, in the case of composite materials made of thermoplastic resin, the thickness is 0.
Even when processed into a sheet as thin as 5 mm or less, it still has sufficient practical X-ray shielding ability, making use of its flexible and easy-to-handle features, giving it the advantage of an extremely high degree of freedom in expanding applications. have The sheet which is an example of the present invention can be manufactured, for example, by the following method, but the method is not limited thereto.

鉛金属を溶融し、孔径が０．０５ｍｎのノズルより吐出
させることにより繊維直径４０μ、長さ５〜７ｍの極細
鉛繊維を紡糸する。この工程に連続して。By melting lead metal and discharging it from a nozzle with a hole diameter of 0.05 mm, ultrafine lead fibers with a fiber diameter of 40 μm and a length of 5 to 7 m are spun. Continue this process.

回転式のカッターを設置することによシ、紡出された繊
維は直ちに切断される。切断部に隣接して。By installing a rotary cutter, the spun fibers are immediately cut. adjacent to the cut.

ふるいを配置し、所望の長さの短繊維だけを採取する。A sieve is placed and only the short fibers of the desired length are collected.

次にこの鉛短繊維を所望の比重のシートが得られるよう
な配合割合で９例えば塩化ビニ・ル樹脂と混合し、可塑
剤等を加えて十分に混練する。Next, the short lead fibers are mixed with, for example, vinyl chloride resin in a blending ratio such that a sheet with a desired specific gravity can be obtained, and a plasticizer and the like are added and thoroughly kneaded.

混線には例えばバンバリーミキサ−等の混線タイプのミ
キサーを使用できる。次にこの極細鉛短繊維配合物を適
正な間隙を有するロール間より押し出してシート状に成
形する。For example, a mixer type mixer such as a Banbury mixer can be used for the crosstalk. Next, this ultrafine short lead fiber mixture is extruded between rolls having appropriate gaps to form a sheet.

かかる複合材料に天然繊維や人造繊維よりなる編織物や
不織布などを貼りつけたり、内部に埋め込んだりしてシ
ートの強力を増大させることも可能であり、目的に応じ
て加工することができる。It is also possible to increase the strength of the sheet by attaching knitted fabrics or non-woven fabrics made of natural fibers or artificial fibers to such composite materials, or by embedding them inside, and it is possible to process them depending on the purpose.

次に実施例をあげて本発明をさらに詳しく説明する。Next, the present invention will be explained in more detail with reference to Examples.

実施例１ 電気鉛を３４０℃で溶融し、直径５０μのノズルより紡
出して繊維直径が約４０μの鉛繊維を製造した。引き続
いて、紡出された繊維を回転式のカッターに導き、長さ
約０．５〜１−の短繊維を得た。Example 1 Electrolytic lead was melted at 340° C. and spun through a nozzle with a diameter of 50 μm to produce lead fibers with a fiber diameter of about 40 μm. Subsequently, the spun fibers were introduced into a rotary cutter to obtain short fibers having a length of about 0.5 to 1-1.

この短繊維を混合量を変えて塩化ビニル樹脂コンパウン
ドと混合し、さらに可塑剤等を添加して。These short fibers are mixed with a vinyl chloride resin compound in varying amounts, and plasticizers are added.

バンバリーミキサ−により十分に混練した後、ロール間
隙より押出して、厚さ０．５国で、比重が４．２（Ａ）
と４．７（Ｂ）の高比重なシートを２枚調製した。After sufficiently kneading with a Banbury mixer, it is extruded through the gap between the rolls to obtain a product with a thickness of 0.5 mm and a specific gravity of 4.2 (A).
Two sheets with a high specific gravity of 4.7 (B) were prepared.

ＪＩＰＪ　　Ｚ−４５０１によって測定したこれらのシ
ートの鉛当量値は（Ａ）　０．１４と（Ｂ）　０．１７
であり。The lead equivalent values of these sheets measured by JIPJ Z-4501 are (A) 0.14 and (B) 0.17.
Yes.

さらにレントゲン写真をＸＪ管電圧１００　ｋ−Ｖｌ）
で撮影したところ、第１図に示すようにピンホール欠点
のない（Ａ）、　（Ｂ）の均質なシートであり、優れた
Ｘ線遮へい性能を有することが分る。Furthermore, the X-ray photograph was taken at XJ tube voltage 100 k-Vl)
As shown in Figure 1, the sheets (A) and (B) were homogeneous without pinhole defects, and were found to have excellent X-ray shielding performance.

比較例１ 酸化鉛（ｐｂｏ　、比重９５）粉末を塩ビコンパウンド
中に混練し、厚さ０．５−のシートを調製した。Comparative Example 1 Lead oxide (pbo, specific gravity: 95) powder was kneaded into a PVC compound to prepare a 0.5-thick sheet.

配合量を３５チ（容積混合率）程度まで増加すると、得
られるシートは著しく、もろくなって使用できなくな！
７．配合量２６．０％　（容積）で、ようやく使用可能
なシートが調製できた。得られたシートの比重は３．５
であり、配合量を増加できないために、これ以上の高比
重化はできなかった。When the blending amount is increased to about 35 cm (volume mixing ratio), the resulting sheet becomes extremely brittle and becomes unusable!
7. A usable sheet was finally prepared with a blending amount of 26.0% (volume). The specific gravity of the obtained sheet is 3.5
Since the blending amount could not be increased, specific gravity could not be increased any further.

鉛当量値は０．０９であり、実施例にくらべて、遮へい
性能的には劣ることがわかる。そこで、高比重化できな
いために、遮へい性能を実施例なみにするにはシート厚
みを約１．５倍はど厚くしなければならなかった。The lead equivalent value was 0.09, indicating that the shielding performance was inferior to that of the example. Therefore, since the specific gravity could not be increased, the sheet thickness had to be increased by about 1.5 times in order to achieve the same shielding performance as the example.

つまり、従来の鉛系粉末を用いたのでは、薄くて、かつ
良好な遮へい性能を有するシートを達成するのは非常に
困難である。In other words, using conventional lead-based powders, it is very difficult to achieve a thin sheet with good shielding performance.

比較例２ 電気鉛を！１４０℃で溶融−紡糸し、直径が１２０　／
Ｊの鉛繊維を製造し、実施例と同様の方法により。Comparative example 2 Electrolytic lead! Melt-spun at 140℃, diameter 120/
J lead fibers were produced in the same manner as in the examples.

長さ１ｙｎｍ以下の短繊維を得た。この鉛短繊維を塩化
ビニル樹脂中に混練し、厚さ０．５　ｒｒｍ　、比重４
．２のシートを調製した。Short fibers having a length of 1 ynm or less were obtained. The short lead fibers were kneaded into vinyl chloride resin to a thickness of 0.5 rrm and a specific gravity of 4.
．． Two sheets were prepared.

Ｊ工５ｚ−４５０１による本シートの鉛当量値は０．１
１と実施例に比較して低い。さらにレントゲン写真で見
ると、Ｘ線の透過したピンホールが顕著に認められる。The lead equivalent value of this sheet according to J Engineering 5z-4501 is 0.1
1, which is lower than that of the example. Furthermore, when looking at the X-ray photograph, pinholes through which X-rays were transmitted can be clearly seen.

このように直径が１２０μと大径の鉛短繊維を用いたの
では、厚みが薄くて、かつ実用的なＸ線遮へい性能を有
するようなシートは得られない。If short lead fibers having a large diameter of 120 μm are used in this way, it is not possible to obtain a sheet that is thin and has practical X-ray shielding performance.

比較例６ 電気鉛を′５４０℃で溶融紡糸し、叶続いてカッターに
導き、直径７０μ、長さ１−以下の鉛短繊維を製造した
。Comparative Example 6 Electrolytic lead was melt-spun at 540° C. and then introduced into a cutter to produce short lead fibers with a diameter of 70 μm and a length of 1 mm or less.

この短繊維を塩化ビニル樹脂と混練し、厚さ０５−のシ
ートを調製した。鉛当量値を向上させれた。しかしなが
ら、第２図に示すように、このシートのレントゲン写真
には、Ｘ線の透過したビンホールが多く認められ、Ｘ線
速へい用途としては致命的な欠点を有する。This short fiber was kneaded with vinyl chloride resin to prepare a sheet with a thickness of 0.5 mm. Improved lead equivalent value. However, as shown in FIG. 2, the X-ray photograph of this sheet shows many holes through which X-rays have passed, which is a fatal drawback for use in X-ray scanning.

また（Ａ）は低比重であるにもかかわらず第２図の９口
き白点はみられず、（Ｂ）に比して多少Ｘ線の透過量が
増加するが、遮へい効果が大きいことがわかる。In addition, although (A) has a low specific gravity, the nine-hole white spot shown in Figure 2 is not seen, and although the amount of X-ray transmission is slightly increased compared to (B), the shielding effect is large. I understand.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は実施例１で得られた（Ａ）、（Ｂ）　２枚のシ
ートをＸ線管電圧１００ｋＶＰで撮影したレントゲン写
真図を示す。 第２図は比較例６で調製したシートについて。 同条件で撮影したレントゲン写真図を示すものである。FIG. 1 shows an X-ray photograph of two sheets (A) and (B) obtained in Example 1, taken at an X-ray tube voltage of 100 kVP. Figure 2 shows the sheet prepared in Comparative Example 6. This shows an X-ray photograph taken under the same conditions.

Claims (1)

【特許請求の範囲】 合成樹脂に鉛金属短繊維を配合してなる複合材料におい
て、該短繊維の直径が６０μ以下であり。 かつ比重が４，０以上であるＸ線遮へい用複合材料。[Claims] A composite material made of a synthetic resin mixed with short lead metal fibers, wherein the short fibers have a diameter of 60 μm or less. An X-ray shielding composite material having a specific gravity of 4.0 or more.