JP3637585B2

JP3637585B2 - Bulletproof material

Info

Publication number: JP3637585B2
Application number: JP15197595A
Authority: JP
Inventors: 敦史森脇; 薫伴; 茂雄阿比留
Original assignee: Toyobo Co Ltd
Current assignee: Toyobo Co Ltd
Priority date: 1995-06-19
Filing date: 1995-06-19
Publication date: 2005-04-13
Anticipated expiration: 2020-04-13
Also published as: JPH093758A

Description

【０００１】
【産業上の利用分野】
本発明は、耐弾用部材に関し、詳しくは、砲弾破片あるいは銃弾を対象とした防弾チョッキをはじめ、不発弾処理や発破作業時の防爆カーテンなどに用いるための、高速で飛行する物体が及ぼす局部的に大きい衝撃力を受止め得る耐弾用部材に関する。
【０００２】
【従来の技術】
高速で飛行する弾丸または砲弾破片などを例にとった場合、このような物体はＭＶ²（Ｍは質量、Ｖは着速度）に比例して負荷威力を増すので、耐弾用部材はこれによる運動エネルギＥ（Ｅ＝ＭＶ²／２）を吸収して物体を停弾させ得る性能を有する必要がある。そのため、高速で飛行する物体の質量および速度が大きい程、さらには飛行する物体を停弾させ得る確率を高めて安全性を確保しようとする程、物体が及ぼす衝撃力を受止め得る耐弾用部材の性能を向上させる必要がある。
【０００３】
防護衣などに用いられた当初の耐弾用部材は、成型した金属板、陶器、ＦＲＰなどの小片を織物に縫い付けたものであった。しかし、この耐弾用部材は、可撓性が低いために、着心地が悪いだけでなく、取扱い難かった。
【０００４】
そのため、これらの問題点を改善するために、およそ１０ｇ／ｄの強度を有する高強力ナイロン糸を用いた耐弾用部材が開発された。しかし、この耐弾用部材には十分な耐弾性能が得られないという問題がある。
【０００５】
一般に、従来の耐弾用部材は、織布または不織布に樹脂を含漬させることにより、その形態保持を行ったハード耐弾材と、繊維の可撓性を生かしたソフト耐弾材とに分けられる。
【０００６】
最近、このハード耐弾材として、一方向に引揃えられた繊維シートを、繊維配列が０゜および９０゜になるようにフィルムを介して積層した後、さらに樹脂を含浸させたシートが開発された。このシートは、ハード耐弾材としては、従来に無い優れた性能を有する。しかし、これらのシートはまた、繊維間の拘束が無いために、衝撃が加えられた際にシート表面に亀裂が発生し、そして大きな衝撃力が連続して加えられると、その効果は著しく激減するという問題を有する。さらに、ハード耐弾材であるために、その重量の２０重量％前後が樹脂であり、ソフト耐弾材に比べて同重量当りの耐弾性能は低い。その結果、性能を向上させるために積層枚数を増やさなければならず、コストがかかるだけでなく、重量が増加して取扱い難いという問題もある。
【０００７】
近年、２０ｇ／ｄを超える単繊維強度を有する芳香族ポリアミド、超高強力ポリエチレン繊維などの超高強度高弾性繊維が新たに開発され、そして上記ソフト耐弾材として、この繊維でなる織物を積層した耐衝撃性が高く、軽量で、取り扱いの容易な耐弾用部材が開発された。この耐弾用部材は、現在、ビル破壊、トンネル工事などの発破作業、不発弾処理のための防爆カーテン、過激派などによるロケット弾に対処するための防爆カーテン、装甲車の内張やＶＩＰ用の演題の内張などに用いられ、その需要も多岐に渡っている。しかし、これらの耐弾用部材であっても、高速で飛行する物体のエネルギー量が大きい場合には、耐弾性能を向上させるために積層枚数を増やさなければならず、コストがかかるだけでなく、重量が増加して取扱い難くなるという問題がある。
【０００８】
そのため、これらの織物を基本としたソフト耐弾材の性能を向上させる具体的な方策として、繊維物性、製織技術などを向上させる試みが行われてきた。例えば、上記のような同一の超高強度高弾性繊維を用いて、最高の耐弾性能を得るためには、従来の織構造においてまず平織にすること、細デニール化させて衝撃力が伝播するネットワークを向上させること、製織時の糸条のダメージを出来るだけ軽減させること、経糸および緯糸の打込み本数を多くすること、繊維を出来るだけ直線的に挿入することなどが行われている。しかし、これらの方法では、生産性が非常に悪く、かつ、耐弾性能の向上もわずかであり、現在の技術水準を考慮すると、これらの方法だけでは、今後大幅な耐弾用部材の耐弾性能の向上は期待出来ない。
【０００９】
【発明が解決しようとする課題】
本発明は、上記問題を解決することを課題とするものであり、その目的は、繊維が有する優れた可撓性および高耐弾特性を１００％生かしたソフト耐弾材であって、軽量で、かつ取扱い性に優れ、高速で飛行する物体が及ぼす局部的に大きい衝撃力を受止め得、そして、耐弾用部材の人体側の変形量を人体に影響を与えない程度の範囲に抑え得る、高い安全性をも有する耐弾用部材を提供することにある。
【００１０】
【課題を解決するための手段】
本発明は、少なくとも２枚の短繊維不織布でなる積層体の少なくとも１面に１枚の織物を縫合してなる、空隙率が７８％以上９８％以下の耐弾用部材であって、上記短繊維不織布は、１８ｇ／ｄ以上の単繊維強度および５００ｇ／ｄ以上の引っ張り弾性率を有する超高強度高弾性繊維を１０ｍｍ以上１５０ｍｍ以下の短繊維から構成される、経緯平均布帛強力が０．０５ｋｇｆ／２ｃｍ以上３０ｋｇｆ／２ｃｍ以下の短繊維不織布であり、上記織物は、該超高強度高弾性繊維により構成され、下式で表されるＣＦ（カバーファクター）
【００１１】
【数２】

【００１２】
が１５００以上２０００以下の織物である、耐弾用部材であり、このことにより上記目的が解決される。
【００１３】
さらに、本発明を詳しく説明する。
【００１４】
本発明に用いられる短繊維不織布は、１８ｇ／ｄ以上の単繊維強度および５００ｇ／ｄ以上引っ張り弾性率を有する超高強度高弾性繊維を１０ｍｍ以上１５０ｍｍ以下の短繊維から構成される、経緯平均布帛強力が０．０５ｋｇｆ／２ｃｍ以上３０ｋｇｆ／２ｃｍ以下の短繊維不織布である。
【００１５】
この超高強度高弾性繊維は、１８ｇ／ｄ以上の単繊維強度および５００ｇ／ｄ以上の引っ張り弾性率を有する超高強度高弾性繊維であれば特に限定することなく使用され得る。これに対して、単繊維強度が１８ｇ／ｄ未満、あるいは、引張り弾性率が５００ｇ／ｄ未満の繊維を上記短繊維不織布に使用した場合には、単位重量あたりの耐弾性能が著しく低下するので、耐弾性能を堅持する部材の重量は重くなり、実用性に欠ける。また、この短繊維不織布に用いられる超高強度高弾性繊維の単繊維強度および引張り弾性率は、高ければ高い程良く、対象とする物体が及ぼす衝撃力、製糸性、および製造コストとの兼ね合いから適宜決定され得る。
【００１６】
この超高強度高弾性繊維としては、全芳香族ポリアミド繊維、ポリパラフェニレンベンズオキサゾール（ＰＢＯ）繊維、ポリパラフェニレンベンズチアゾール（ＰＢＴ）繊維、ポリエチレン、ポリプロピレンなどのポリオレフィン繊維、ポリアクリロニトリル繊維、ポリ（フッ化）ビニリデン繊維、全芳香族ポリエステル繊維、ボロン繊維などが用いられ得る。
【００１７】
特に、本発明の耐弾用部材が軽量となるためには、上記超高強度弾性繊維は束ねられた際に、一定の空隙を有することが所望される。従って、上記超高強度高弾性繊維には、好ましくは横断面偏平率が１．５以上１２．０以下のポリエチレン繊維が用いられる。さらに、上記超高強度高弾性繊維は、耐弾性能を向上させる点から、横断面偏平率が１．７以上８．０以下のポリエチレン繊維を用いることが好ましい。これに対し、横断面偏平率が１．５未満である場合には、繊維の剛直性が増すために、耐弾用部材間を通過する弾などの物体に対する繊維の絡み付きが弱くなる。横断面偏平率が１２．０を越える場合には、繊維横断面の長軸側の両サイドに応力が集中して、衝撃力に対する繊維の強度が低下する。ここで言う、繊維の横断面偏平率とは、下式で表される値のことである。
【００１８】
【数３】

【００１９】
さらに上記超高強度高弾性繊維として用いられるポリエチレン繊維は、平均分子量が５×１０⁵以上の高分子量を有することが好ましい。
【００２０】
上記短繊維不織布は、これらの超高強度高弾性繊維を、１０ｍｍ以上１５０ｍｍ以下、そしてエネルギーの吸収効率および換算効率を高める点から好ましくは２０ｍｍ以上１００ｍｍ以下の短繊維により構成される。１０ｍｍ未満の繊維により構成された不織布は、その製造工程において、取扱い性を向上させる点から絡合度を上げる必要があり、その結果、構成する繊維の損傷を増加させる。さらに、このような不織布は、大きな衝撃力が加わえられると、構成される非常に短い繊維のために、この繊維が伸びて破断するより前に絡合が解け、エネルギー吸収効率が著しく低下する。反対に１５０ｍｍを超える繊維により構成された不織布は、その製造工程において開繊不良などの問題を生じ、均質なシートが得られにくい。さらに、このような不織布は構成される繊維が長繊維化するほど単繊維間の自由度が束縛されるので、局部的に大きな衝撃力が加わえられた際に、弾丸などの物体が繊維間を分け入る現象が起こりエネルギー換算効率が低下する。
【００２１】
この短繊維不織布は、例えば、上記超高強度高弾性繊維を１０ｍｍ以上１５０ｍｍ以下の短繊維に切断してシート状にした後、公知の絡合処理を施すことにより得られ得る。
【００２２】
得られた短繊維不織布は、経緯平均布帛強力が０．０５ｋｇｆ／２ｃｍ以上３０ｋｇｆ／２ｃｍ以下であり、そして取扱い性および耐弾性能を向上させる点から０．１ｋｇｆ／２ｃｍ以上１５ｋｇｆ／２ｃｍ以下であることが好ましい。短繊維不織布の経緯平均布帛強力が０．０５ｋｇｆ／２ｃｍ未満である場合には、不織布自体の強力が小さすぎるため、取扱い性が非常に低下し、反対に経緯平均布帛強力が３０ｋｇｆ／２ｃｍを越える場合には、この不織布を構成する繊維間の自由度が著しく低減され、単位重量当りの耐弾性能が低下する。
【００２３】
本発明に用いられる織物は、上記短繊維不織布を構成する超高強度高弾性繊維、すなわち１８ｇ／ｄ以上の単繊維強度および５００ｇ／ｄ以上の引っ張り弾性率を有する超高強度高弾性繊維により構成されている。単繊維強度が１８ｇ／ｄ未満、あるいは、引張り弾性率が５００ｇ／ｄ未満の繊維をこの織物に使用した場合には、局部的に大きな衝撃力を瞬時、かつ広範囲に伝播し得ず、エネルギーを受止める能力に欠け、さらに耐弾用部材の局部的変形量も大きくなる。その結果、この耐弾用部材を着用する身体に対する安全性が失われる。この織物に用いられる超高強度高弾性繊維の単繊維強度および引張り弾性率は、高ければ高い程良く、対象とする物体が及ぼす衝撃力、製糸性、および製造コストとの兼ね合いで適宜決定され得る。
【００２４】
上記短繊維不織布および織物に用いられる超高強度高弾性繊維は、単繊維強度が１８ｇ／ｄ以上で引張り弾性率が５００ｇ／ｄ以上である範囲にあればよく、一つの耐弾用部材に用いられる短繊維不織布と織物とを構成する超高強度高弾性繊維が全て同一である必要はない。
【００２５】
上記織物は、下式で表されるＣＦ（カバーファクター）
【００２６】
【数４】

【００２７】
が１５００以上２０００以下であり、得られる織物が衝撃力の伝播に優れる点および局部的変形量が小さい点から、１６００以上１９５０以下であることが好ましい。ＣＦが１５００未満である場合には、局部的に大きな衝撃力に対して、織物を構成する糸条間の目がずれる現象が発生し、局部的に大きな衝撃力を瞬時、かつ広範囲に伝播し得ず、エネルギーを受止める能力に欠け、また耐弾用部材の局部的変形量も大きくなるので、この耐弾用部材を着用する身体に対する安全性が失われる。反対にＣＦが２０００を越える場合には、織物を構成する糸条を製織する際に、横からの強い力を受けて糸条の繊維が損傷し、織物の厚み方向に糸条が大きくループする。その結果、得られる織物は、衝撃力を伝播しにくい、すなわち耐弾性能に劣る。
【００２８】
上記織物は、上記超高強度高弾性繊維を公知の方法を用いて製織することにより得られ得る。このときの織組織には、平織、斜文織、または朱子織だけでなく、いずれの織組織も用いられ得る。しかし、上記織物は、変形を小さくする点から平織が好ましい。
【００２９】
上記織物は、好ましくは耐弾用部材の総重量に対し３重量％以上４０重量％以下で、さらに好ましくは５重量％以上２０重量％以下の割合で使用される。上記織物が３重量％未満である場合には、積層した短繊維不織布の変形に伴う衝撃力を受止める能力が不足し易くなり、反対に４０重量％を越える場合には、同重量であっても短繊維不織布の割合が少ないために耐弾性能が劣る場合が多いからである。
【００３０】
本発明の耐弾用部材は、例えば、通常の縫合材料を用いる公知の手順により、上記短繊維不織布および織物を縫合して得られる。このとき、少なくとも２枚の上記短繊維不織布でなる積層体の少なくとも１面に１枚の上記織物が縫合される。上記織物を縫合しない上記短繊維不織布のみでは、糸条間の拘束が弱いために、衝撃力によって形態が破壊される。その結果、耐弾用部材の変形量が増大し、大きな衝撃力が繰り返し加えられると、初期と同様の耐弾性能を保持し得ないという品質保証上の問題が生じる。さらに、この変形量の増大は、たとえ停弾しても人体に大きな影響を与えるので、耐弾用部材を防弾チョッキなど身体に直接接触する分野には使用出来ない。そのため、衝撃力が加えられる面に対し、少なくともその裏面側には上記織物を縫合する必要がある。短繊維不織布を表層に有する耐弾用部材はまた、毛羽立ち、ピリングなどの品質低下が起こりやすいことから、裏面側に加えて、表面側にも上記織物が縫合されることが望ましい。
【００３１】
本発明の耐弾用部材の空隙率は、７８％以上９８％以下であり、耐弾性能および取扱い性を向上させる点から８５％以上９６％以下であることが好ましく、そして、取扱い性の許す限りこの範囲でできるだけ高い値であることがさらに好ましい。耐弾用部材の空隙率が７８％未満である場合、構成する短繊維不織布および織物の繊維の自由度は損なわれ、単位重量当りの耐弾性能が低下する。反対に空隙率が９８％を越える場合、取扱い性が非常に低下し、品質管理の点で問題が生じる。なお、ここで言う、空隙率とは、下式で表される値のことである。
【００３２】
【数５】

【００３３】
このようにして、少なくとも２枚の短繊維不織布でなる積層体の少なくとも１面に１枚の織物を縫合してなる、耐弾用部材が得られる。
【００３４】
【実施例】
以下、本発明の実施例および比較例を挙げて、本発明の耐弾用部材の性能が優れていることを説明する。
【００３５】
（実施例１）
超高強度高弾性繊維として、単繊維強度が３３ｇ／ｄ、引張り弾性率が１０００ｇ／ｄ、横断面偏平率が５．３の高強度ポリエチレン繊維を用いた。この繊維を、５１ｍｍにカットし、シート状に積層した後、ニードルパンチによる絡合処理を施し、目付けが２５３ｇ／ｍ²、経緯平均布帛強力が５．３ｋｇｆ／２ｃｍの短繊維不織布を得た。
【００３６】
同じく単繊維強度が３３ｇ／ｄ、引張り弾性率が１０００ｇ／ｄ、横断面偏平率が５．３、トータル４００デニールの高強度ポリエチレン繊維を経糸および緯糸に用いて、経糸密度および緯糸密度がそれぞれ４６本／インチ、ＣＦが１８５７、そして目付けが１７４ｇ／ｍ²の織物を得た。
【００３７】
次いで、上記で得られた短繊維不織布を１１枚積層した後、その表面側および裏面側に、上記で得られた織物を縫合し、縦横３０ｃｍの大きさに切り出して、厚みが４０ｍｍ、トータル目付けが３１３１ｇ／ｍ²、空隙率が９２％の耐弾用部材を得た。
【００３８】
上記で得られた耐弾用部材２枚に、質量１．１ｇで円柱状の模擬破片弾を、弾速４４０ｍ／秒以上５５０ｍ／秒以下の範囲内で、貫通または非貫通の割合が半々になる様にそれぞれ１２発づつ、計２４発発射した。このうち、貫通弾の低速側より５点、非貫通弾の高速側より５点のデータを採用し、その平均値（Ｖ５０）から耐弾性能を評価した。ただし、採用データの着弾位置は、前着弾位置よりも経緯方向各５ｃｍ以上、斜め方向各２ｃｍ以上離れていることを前提とする。このようにして算出されたＶ５０は、４９２．７ｍ／秒であった。
【００３９】
さらに上記耐弾用部材を厚み１０ｃｍの油粘土に接触させた状態での停弾時のトラウマ量（粘土の凹み量）を測定した。その結果は、１４ｍｍと非常に良好な値であった。
【００４０】
（実施例２）
実施例１と同様の高強度ポリエチレン繊維を用い、これを３０ｍｍにカットしたこと以外は実施例１と同様にして、目付けが１８１ｇ／ｃｍ²、経緯平均布帛強力が０．１５ｋｇｆ／２ｃｍの短繊維不織布を得た。
【００４１】
次いで、この短繊維不織布を１４枚積層したこと以外は、実施例１で得られた織物を用いて、実施例１と同様に縫合し、切り出しを行い、厚みが５０ｍｍ、トータル目付けが２８８２ｇ／ｍ²、空隙率が９４％の耐弾用部材を得た。
【００４２】
上記で得られた耐弾用部材２枚に、弾速４５０ｍ／秒以上５６０ｍ／秒以下の範囲内で発射したこと以外は、実施例１と同様にしてＶ５０を算出した。その結果は、４９２．７ｍ／秒であった。
【００４３】
さらに、実施例１と同様にトラウマ量を測定した。その結果は、１５ｍｍと防護衣としても使用可能な、非常に良好な値であった。
【００４４】
（比較例１）
現在、防弾チョッキとして使用実績のある単繊維強度が２４ｇ／ｄ、引張り弾性率が６５０ｇ／ｄ、３０００デニールのアラミド（芳香族ポリアミド）糸からなる経糸密度および緯糸密度が１７本／インチ、目付けが４６０ｇ／ｍ²、ＣＦが１５４１の織物を１３枚積層して、厚みが８ｍｍ、トータル目付けが５９８０ｇ／ｍ²、空隙率が４９％の耐弾用部材を得た。
【００４５】
上記で得られた耐弾用部材２枚に、模擬破片弾を弾速４４０ｍ／秒以上５４０ｍ／秒以下の範囲内で発射したこと以外は、実施例１と同様にしてＶ５０を算出した。その結果は、４８３．８ｍ／秒であった。
【００４６】
さらに、実施例１と同様にトラウマ量を測定した。その結果は、１４ｍｍと非常に良好な値であった。
【００４７】
（比較例２）
織物を用いることなく、実施例１で得られた短繊維不織布を８枚積層したこと以外は、実施例１と同様に切り出しを行い、厚みが４０ｍｍ、トータル目付けが２０２４ｇ／ｍ²、空隙率が９５％の耐弾用部材を得た。
【００４８】
上記で得られた耐弾用部材２枚を用いて、模擬断片を弾速４３０ｍ／秒以上５３０ｍ／秒以下の範囲内で発射したこと以外は、実施例１と同様にしてＶ５０を算出した。その結果は、４８０．５ｍ／秒であった。
【００４９】
さらに、実施例１と同様にトラウマ量を測定した。その結果は５４ｍｍと非常に大きく、身体に直接接触する箇所の使用においては安全性の問題があると判明した。さらに、一回の衝撃力により、この耐弾用部材は、原形を止めない位に破壊され、複数の物体が及ぼす衝撃力に対しては、品質が保証できないという問題が残った。
【００５０】
（比較例３）
実施例１と同様の高強度ポリエチレン繊維を経糸および緯糸に用いて、経糸密度および緯糸密度がそれぞれ２３本／インチ、ＣＦが９２９、目付けが８７ｇ／ｍ²の織物を得た。
【００５１】
実施例１で得られた短繊維不織布を１１枚積層した後、この織物を用いたこと以外は実施例１と同様に縫合し、切り出しを行い、厚みが３９ｍｍ、トータル目付けが２９５７ｇ／ｍ²、空隙率が９２％の耐弾用部材を得た。
【００５２】
上記で得られた耐弾用部材２枚を用い、実施例１と同様にしてＶ５０を算出した。その結果は、４８６．５ｍ／秒であった。
【００５３】
さらに、実施例１と同様にトラウマ量を測定した。その結果は、２６ｍｍと大きく、身体に直接接触する箇所の使用においては、安全性の問題があると判明した。
【００５４】
《各耐弾用部材の比較》
上記のようにして得られた各実施例および各比較例の単位重量あたりの耐弾性能を比較するために、単位重量あたりの耐弾エネルギー量を以下の式から算出した。その結果から、比較例１の耐弾用部材の耐弾エネルギー量を１００％としたときの各耐弾用部材の耐弾比率（％）を求めた。この結果を、上記全ての結果とともに表１に示す。
【００５５】
【数６】

【００５６】
【表１】

【００５７】
表１からわかるように、比較例１の耐弾用部材に比べて、実施例１および２の耐弾用部材は、同重量あたりの耐弾性能は２倍程度であった。このことは、従来の比較例の耐弾用部材の半分程度の重さ、すなわち５０％程度の軽量化を行っても、同様の性能を得ることが出来ることが証明されたといえる。また、２倍のエネルギー量を有する物体が及ぼす衝撃力に対しても同重量で対応し得ることが証明されたといえる。またトラウマ量も比較例１の耐弾用部材と同等であり、防弾チョッキとしても十分使用可能であることが確認された。
【００５８】
【発明の効果】
以上のように、本発明の耐弾用部材は、従来の同一の超高強度高弾性繊維を用いた織物では到達し得なかった高い単位重量当りの耐弾性能を有する、超高強度高弾性繊維の性能を十分に利用したこれらの繊維の積層体の構造を有する。具体的には、耐弾部材内を通過する弾丸に超高強度高弾性繊維を十分絡ませるだけの自由度を持たせて見掛上の弾径を大きくすること、および、それを受け止める超高強度高弾性繊維で構成される織物の織密度を高くし、局部的に大きな衝撃力に対する糸条間の目のずれを防止して衝撃吸収範囲を拡大することによって、耐弾性能を高め、かつ耐弾用部材の人体側の変形量も人体への影響がない範囲まで軽減することが可能となる。
【００５９】
そのため、従来の織物では成し得なかった単位重量当りの優れた耐弾性能を有するだけでなく、従来の織物と同等の耐弾部材の人体側の変形量が得られ、かつ大幅な軽量化による取扱い性の向上とともに、高い安全性を有する耐弾用部材を提供することができる。[0001]
[Industrial application fields]
The present invention relates to a bulletproof member, and more particularly, a local effect exerted by an object flying at a high speed for use in a bulletproof vest for bullet fragments or bullets, an unexploded shell treatment or an explosion-proof curtain during a blasting operation, etc. The present invention relates to a bulletproof member capable of receiving a large impact force.
[0002]
[Prior art]
Taking bullets or shell fragments that fly at high speed as an example, such an object increases the load power in proportion to MV ² (M is mass, V is landing speed), so the bulletproof member is absorbs kinetic energy ^{E (E = MV 2/2} ) should have a performance capable of Tomatama object. Therefore, the higher the mass and speed of an object flying at high speed, and the higher the probability that the flying object can be stopped, the more it is intended to ensure safety, the more it can withstand impact force exerted by the object. It is necessary to improve the performance of the member.
[0003]
The original bulletproof members used in protective clothing and the like were obtained by sewing small pieces such as molded metal plates, earthenware, and FRP onto a fabric. However, since this bulletproof member has low flexibility, it is not only difficult to wear but also difficult to handle.
[0004]
Therefore, in order to improve these problems, a ballistic-resistant member using a high-strength nylon thread having a strength of about 10 g / d has been developed. However, this ballistic member has a problem that sufficient ballistic performance cannot be obtained.
[0005]
In general, conventional ballistic resistant members are divided into hard bulletproof materials that retain their form by impregnating resin in woven or non-woven fabrics, and soft bulletproof materials that take advantage of fiber flexibility. It is done.
[0006]
Recently, as this hard bulletproof material, a sheet in which fiber sheets aligned in one direction are laminated through a film so that the fiber arrangement becomes 0 ° and 90 °, and then further impregnated with resin has been developed. It was. This sheet has excellent performance as a hard bulletproof material, which has never been obtained. However, these sheets also have no fiber-to-fiber restraints, so that when the impact is applied, the sheet surface cracks, and when a large impact force is applied continuously, the effect is drastically reduced. Have the problem. Furthermore, since it is a hard bulletproof material, about 20% by weight of its weight is resin, and its ballistic performance per weight is lower than that of a soft bulletproof material. As a result, in order to improve the performance, the number of stacked layers must be increased, which is not only costly, but also increases the weight and is difficult to handle.
[0007]
In recent years, ultra-high-strength and high-elasticity fibers such as aromatic polyamide having a single fiber strength exceeding 20 g / d and ultra-high-strength polyethylene fiber have been newly developed, and a woven fabric made of this fiber is laminated as the soft bulletproof material. An impact resistant, lightweight, and easy to handle ballistic member has been developed. These bulletproof members are currently used for blasting work such as building destruction and tunnel construction, explosion-proof curtains for handling unexploded bullets, explosion-proof curtains for dealing with rockets caused by extremists, armored vehicle lining and VIP It is used for the lining of the subject, and the demand is also diverse. However, even with these bulletproof members, if the amount of energy of an object flying at high speed is large, the number of layers must be increased in order to improve the bulletproof performance. There is a problem that the weight increases and handling becomes difficult.
[0008]
Therefore, attempts have been made to improve fiber properties, weaving technology, and the like as specific measures for improving the performance of soft bulletproof materials based on these fabrics. For example, in order to obtain the best ballistic resistance performance using the same ultra-high-strength and high-elastic fiber as described above, the impact force is propagated by first making a plain weave in a conventional woven structure and making it fine denier. In order to improve the network, to reduce the damage of the yarn during weaving as much as possible, to increase the number of warps and wefts to be driven, and to insert the fibers as linearly as possible. However, these methods are very poor in productivity and have little improvement in ballistic resistance. Considering the current state of the art, these methods alone will greatly increase the ballistic resistance of the ballistic members. The improvement in performance cannot be expected.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems, and the object thereof is a soft bulletproof material that makes full use of the excellent flexibility and high bulletproof properties of the fiber, and is lightweight. In addition, it is easy to handle, can accept a large impact force exerted by an object flying at high speed, and can suppress the amount of deformation on the human body side of the bulletproof member to a range that does not affect the human body. Another object of the present invention is to provide a bulletproof member having high safety.
[0010]
[Means for Solving the Problems]
The present invention provides a bulletproof member having a porosity of 78% or more and 98% or less, which is formed by stitching one woven fabric to at least one surface of a laminate composed of at least two short fiber nonwoven fabrics. The nonwoven fabric is composed of ultra-high-strength and high-elasticity fibers having a single fiber strength of 18 g / d or more and a tensile modulus of 500 g / d or more, consisting of short fibers of 10 mm or more and 150 mm or less. / 2 cm to 30 kgf / 2 cm short fiber nonwoven fabric, the woven fabric is composed of the ultra high strength and high elastic fiber, and is represented by the following formula (CF)
[0011]
[Expression 2]

[0012]
Is a member for ballistic resistance, which is a woven fabric of 1500 or more and 2000 or less.
[0013]
Further, the present invention will be described in detail.
[0014]
The short fiber nonwoven fabric used in the present invention is a background average fabric comprising ultra high strength and high elastic fibers having a single fiber strength of 18 g / d or more and a tensile modulus of elasticity of 500 g / d or more, consisting of short fibers of 10 mm or more and 150 mm or less. A short fiber nonwoven fabric having a strength of 0.05 kgf / 2 cm or more and 30 kgf / 2 cm or less.
[0015]
The ultra high strength and high elasticity fiber can be used without particular limitation as long as it is a single fiber strength of 18 g / d or more and a tensile elastic modulus of 500 g / d or more. In contrast, when a fiber having a single fiber strength of less than 18 g / d or a tensile elastic modulus of less than 500 g / d is used for the short fiber nonwoven fabric, the ballistic resistance per unit weight is remarkably lowered. In addition, the weight of the member that maintains the ballistic performance becomes heavy and lacks practicality. In addition, the higher the single fiber strength and tensile modulus of the ultra-high-strength and high-elasticity fibers used in this short fiber nonwoven fabric, the better. From the balance of impact force, yarn-making property, and production cost exerted by the object. It can be determined appropriately.
[0016]
Examples of the ultra-high strength and high elasticity fiber include wholly aromatic polyamide fiber, polyparaphenylene benzoxazole (PBO) fiber, polyparaphenylene benzthiazole (PBT) fiber, polyolefin fibers such as polyethylene and polypropylene, polyacrylonitrile fiber, poly ( Fluorinated) vinylidene fibers, wholly aromatic polyester fibers, boron fibers and the like can be used.
[0017]
In particular, in order for the ballistic resistant member of the present invention to be lightweight, it is desirable that the ultrahigh strength elastic fiber has a certain gap when bundled. Therefore, a polyethylene fiber having a cross-sectional flatness ratio of 1.5 or more and 12.0 or less is preferably used for the ultra high strength and high elasticity fiber. Furthermore, it is preferable to use a polyethylene fiber having a cross-sectional flatness of 1.7 or more and 8.0 or less as the ultra high strength and high elasticity fiber from the viewpoint of improving the ballistic performance. On the other hand, when the cross-sectional flatness is less than 1.5, the fiber becomes more rigid, so that the entanglement of the fiber with respect to an object such as a bullet passing between the ballistic members is weakened. When the cross-sectional flatness exceeds 12.0, stress concentrates on both sides of the fiber cross-section on the long axis side, and the strength of the fiber against the impact force decreases. The cross-sectional flatness of the fiber referred to here is a value represented by the following formula.
[0018]
[Equation 3]

[0019]
Furthermore, it is preferable that the polyethylene fiber used as the ultrahigh strength and high elasticity fiber has a high molecular weight having an average molecular weight of 5 × 10 ⁵ or more.
[0020]
The short fiber nonwoven fabric is composed of these ultra high strength and high elasticity fibers of 10 mm to 150 mm, and preferably short fibers of 20 mm to 100 mm in order to increase energy absorption efficiency and conversion efficiency. A nonwoven fabric composed of fibers of less than 10 mm needs to increase the degree of entanglement from the viewpoint of improving the handleability in the production process, and as a result, increases the damage of the constituent fibers. In addition, such nonwoven fabrics, when subjected to a large impact force, break up in entanglement before the fibers stretch and break due to the very short fibers that are constructed and the energy absorption efficiency is significantly reduced. . On the contrary, a nonwoven fabric composed of fibers exceeding 150 mm causes problems such as poor opening in the production process, and it is difficult to obtain a uniform sheet. Furthermore, since the degree of freedom of a single fiber becomes more constrained as the fibers of such a non-woven fabric become longer, when a large impact force is applied locally, objects such as bullets are placed between the fibers. The phenomenon that splits in occurs and the energy conversion efficiency decreases.
[0021]
This short fiber nonwoven fabric can be obtained, for example, by cutting the ultra high strength and high elasticity fiber into short fibers of 10 mm or more and 150 mm or less to form a sheet, and then performing a known entanglement treatment.
[0022]
The obtained short fiber nonwoven fabric has a background average fabric strength of 0.05 kgf / 2 cm or more and 30 kgf / 2 cm or less, and 0.1 kgf / 2 cm or more and 15 kgf / 2 cm or less from the viewpoint of improving handleability and ballistic performance. It is preferable. When the background average fabric strength of the short fiber nonwoven fabric is less than 0.05 kgf / 2 cm, the strength of the nonwoven fabric itself is too small, so that the handleability is very low. On the contrary, the background average fabric strength exceeds 30 kgf / 2 cm. In such a case, the degree of freedom between fibers constituting the nonwoven fabric is remarkably reduced, and the ballistic performance per unit weight is lowered.
[0023]
The woven fabric used in the present invention is composed of ultra-high-strength high-elasticity fibers constituting the above-mentioned short fiber nonwoven fabric, that is, ultra-high-strength high-elasticity fibers having a single fiber strength of 18 g / d or more and a tensile elastic modulus of 500 g / d or more. Has been. When a fiber having a single fiber strength of less than 18 g / d or a tensile modulus of less than 500 g / d is used in this fabric, a large impact force cannot be propagated instantaneously and over a wide area, and energy is saved. It lacks the ability to receive and further increases the amount of local deformation of the bulletproof member. As a result, the safety for the body wearing this bulletproof member is lost. The higher the single fiber strength and tensile elastic modulus of the ultra-high-strength high-elasticity fiber used in this fabric, the better, and it can be determined as appropriate in consideration of the impact force exerted by the target object, the yarn-forming property, and the manufacturing cost. .
[0024]
The ultra-high-strength and high-elasticity fiber used for the above-mentioned short fiber nonwoven fabric and woven fabric only needs to be in a range where the single fiber strength is 18 g / d or more and the tensile elastic modulus is 500 g / d or more. It is not necessary that the ultrahigh-strength and high-elasticity fibers constituting the short fiber nonwoven fabric and the woven fabric are the same.
[0025]
The fabric is CF (cover factor) represented by the following formula
[0026]
[Expression 4]

[0027]
Is from 1500 to 2000, and it is preferably from 1600 to 1950 from the viewpoint that the resulting woven fabric is excellent in propagation of impact force and has a small amount of local deformation. When the CF is less than 1500, a phenomenon occurs in which the yarns constituting the woven fabric are misaligned with respect to a locally large impact force, and the locally large impact force is propagated instantaneously and over a wide range. In addition, the ability to receive energy is lacking, and the amount of local deformation of the ballistic member is increased, so the safety of the body wearing the ballistic member is lost. On the other hand, when the CF exceeds 2000, when weaving the yarn constituting the woven fabric, the yarn fiber is damaged due to a strong force from the side, and the yarn loops greatly in the thickness direction of the woven fabric. . As a result, the resulting woven fabric is difficult to propagate impact force, that is, inferior in ballistic performance.
[0028]
The woven fabric can be obtained by weaving the ultra high strength and high elasticity fiber using a known method. As the weave structure at this time, not only plain weave, oblique weave, or satin weave, but any weave structure can be used. However, the woven fabric is preferably a plain weave from the viewpoint of reducing deformation.
[0029]
The woven fabric is preferably used in a proportion of 3 to 40% by weight, more preferably 5 to 20% by weight, based on the total weight of the ballistic member. When the woven fabric is less than 3% by weight, the ability to receive the impact force associated with the deformation of the laminated short fiber nonwoven fabric tends to be insufficient. On the contrary, when it exceeds 40% by weight, the weight is the same. This is because the ratio of the short fiber nonwoven fabric is small and the ballistic performance is often inferior.
[0030]
The bulletproof member of the present invention is obtained by stitching the short fiber nonwoven fabric and the woven fabric, for example, by a known procedure using a normal stitching material. At this time, one woven fabric is stitched to at least one surface of the laminate made of at least two short fiber nonwoven fabrics. With only the short fiber nonwoven fabric that does not sew the woven fabric, the form is destroyed by the impact force because the constraint between the yarns is weak. As a result, when the amount of deformation of the bulletproof member increases and a large impact force is repeatedly applied, a problem in quality assurance that the same bulletproof performance as in the initial stage cannot be maintained occurs. Furthermore, since the increase in the deformation amount has a great influence on the human body even if the bullet is stopped, it cannot be used in a field where the bulletproof member is in direct contact with the body, such as a bulletproof vest. Therefore, it is necessary to sew the woven fabric at least on the back side of the surface to which the impact force is applied. The bulletproof member having a short fiber nonwoven fabric on the surface layer is also liable to deteriorate in quality such as fuzzing and pilling. Therefore, it is desirable that the woven fabric is sewn on the front side in addition to the back side.
[0031]
The void ratio of the ballistic resistant member of the present invention is 78% or more and 98% or less, preferably 85% or more and 96% or less from the viewpoint of improving the ballistic performance and handleability, and permits handling. It is more preferable that the value be as high as possible within this range. When the porosity of the ballistic resistant member is less than 78%, the degree of freedom of the constituent short fiber nonwoven fabric and woven fabric is impaired, and the ballistic performance per unit weight is lowered. On the other hand, when the porosity exceeds 98%, the handleability is greatly lowered, and a problem arises in terms of quality control. In addition, the porosity mentioned here is a value represented by the following formula.
[0032]
[Equation 5]

[0033]
In this way, a bulletproof member is obtained, in which one woven fabric is stitched to at least one surface of a laminate made of at least two short fiber nonwoven fabrics.
[0034]
【Example】
Hereinafter, the performance of the ballistic resistant member of the present invention will be described with reference to examples and comparative examples of the present invention.
[0035]
(Example 1)
As the ultra high strength and high elasticity fiber, a high strength polyethylene fiber having a single fiber strength of 33 g / d, a tensile modulus of elasticity of 1000 g / d, and a cross-sectional flatness of 5.3 was used. This fiber was cut into 51 mm, laminated in a sheet shape, and then entangled with a needle punch to obtain a short fiber nonwoven fabric having a basis weight of 253 g / m ² and a background average fabric strength of 5.3 kgf / 2 cm.
[0036]
Similarly, high-strength polyethylene fibers having a single fiber strength of 33 g / d, a tensile modulus of elasticity of 1000 g / d, a cross-sectional flatness of 5.3, and a total of 400 denier are used for the warp and the weft, and the warp density and the weft density are 46 respectively. A woven fabric having a line / inch, a CF of 1857, and a basis weight of 174 g / m ² was obtained.
[0037]
Next, after laminating 11 sheets of the short fiber nonwoven fabric obtained above, the woven fabric obtained above was stitched to the front side and the back side, cut into a size of 30 cm in length and width, and the thickness was 40 mm, total basis weight Was 3131 g / m ² , and a bulletproof member having a porosity of 92% was obtained.
[0038]
The two bullet-proof members obtained above were subjected to a half-penetration rate of half of the simulated fragmentary bullet with a mass of 1.1 g within a range of 440 m / sec to 550 m / sec. In total, 24 shots were made, each with 12 shots. Among these, the data of 5 points from the low speed side of the penetrating bullet and 5 points from the high speed side of the non-penetrating bullet were adopted, and the ballistic performance was evaluated from the average value (V50). However, it is assumed that the landing position of the adopted data is 5 cm or more in the weft direction and 2 cm or more in the oblique direction from the previous landing position. The V50 calculated in this way was 492.7 m / sec.
[0039]
Further, the amount of trauma (the amount of dents in the clay) was measured when the bulletproof member was in contact with oil clay having a thickness of 10 cm. The result was a very good value of 14 mm.
[0040]
(Example 2)
A short fiber having a basis weight of 181 g / cm ² and a background average fabric strength of 0.15 kgf / 2 cm, except that the same high-strength polyethylene fiber as in Example 1 was used and the fiber was cut to 30 mm. A nonwoven fabric was obtained.
[0041]
Next, except that 14 sheets of the short fiber nonwoven fabric were laminated, the fabric obtained in Example 1 was used for stitching and cutting in the same manner as in Example 1, the thickness was 50 mm, and the total basis weight was 2882 g / m. ^2. A bulletproof member having a porosity of 94% was obtained.
[0042]
V50 was calculated in the same manner as in Example 1 except that the two bullet-proof members obtained above were fired within a range of bullet velocity of 450 m / second or more and 560 m / second or less. The result was 492.7 m / sec.
[0043]
Further, the amount of trauma was measured in the same manner as in Example 1. The result was a very good value of 15 mm, which can be used as a protective garment.
[0044]
(Comparative Example 1)
Currently used as a bulletproof vest, single fiber strength is 24g / d, tensile elastic modulus is 650g / d, 3,000 denier aramid (aromatic polyamide) yarn density of 17 yarns / inch, weft density is 460g Thirteen woven fabrics having a / m ² and CF of 1541 were laminated to obtain a ballistic resistant member having a thickness of 8 mm, a total basis weight of 5980 g / m ² , and a porosity of 49%.
[0045]
V50 was calculated in the same manner as in Example 1 except that simulated fragment bullets were fired within the range of 440 m / sec to 540 m / sec on the two bulletproof members obtained above. The result was 483.8 m / sec.
[0046]
Further, the amount of trauma was measured in the same manner as in Example 1. The result was a very good value of 14 mm.
[0047]
(Comparative Example 2)
Except that eight sheets of the short fiber nonwoven fabric obtained in Example 1 were laminated without using a woven fabric, cutting was performed in the same manner as in Example 1, the thickness was 40 mm, the total basis weight was 2024 g / m ² , and the porosity was A 95% ballistic resistant member was obtained.
[0048]
V50 was calculated in the same manner as in Example 1 except that the two pieces for ballistic resistance obtained above were used and the simulated piece was fired within a range of bullet speed of 430 m / sec to 530 m / sec. The result was 480.5 m / sec.
[0049]
Further, the amount of trauma was measured in the same manner as in Example 1. The result was very large at 54 mm, and it was found that there was a safety problem in the use of the part in direct contact with the body. Furthermore, the impact-resistant member is destroyed to such an extent that the original shape cannot be stopped, and the quality of the impact force exerted by a plurality of objects cannot be guaranteed.
[0050]
(Comparative Example 3)
The same high-strength polyethylene fiber as in Example 1 was used for the warp and the weft to obtain a woven fabric having a warp density and a weft density of 23 yarns / inch, a CF of 929, and a basis weight of 87 g / m ² .
[0051]
After 11 sheets of the short fiber nonwoven fabric obtained in Example 1 were laminated, the fabric was sewn and cut out in the same manner as in Example 1 except that this woven fabric was used. The thickness was 39 mm, the total basis weight was 2957 g / m ² , A bulletproof member having a porosity of 92% was obtained.
[0052]
V50 was calculated in the same manner as in Example 1 using the two bulletproof members obtained above. The result was 486.5 m / sec.
[0053]
Further, the amount of trauma was measured in the same manner as in Example 1. The result was as large as 26 mm, and it was found that there was a safety problem in the use of the portion in direct contact with the body.
[0054]
<Comparison of each bulletproof member>
In order to compare the ballistic performance per unit weight of each Example and each Comparative Example obtained as described above, the amount of ballistic energy per unit weight was calculated from the following equation. From the results, the ballistic resistance ratio (%) of each ballistic member when the ballistic energy amount of the ballistic member of Comparative Example 1 was 100% was determined. The results are shown in Table 1 together with all the above results.
[0055]
[Formula 6]

[0056]
[Table 1]

[0057]
As can be seen from Table 1, as compared with the ballistic resistant member of Comparative Example 1, the ballistic resistant members of Examples 1 and 2 had about two times the ballistic performance per weight. This proves that the same performance can be obtained even when the weight of the conventional ballistic resistant member of the comparative example is about half, that is, about 50% lighter. In addition, it can be said that it was proved that the impact force exerted by an object having twice the amount of energy can be handled with the same weight. Moreover, the amount of trauma was also equivalent to the bulletproof member of Comparative Example 1, and it was confirmed that the trauma amount can be used sufficiently as a bulletproof vest.
[0058]
【The invention's effect】
As described above, the ballistic resistant member of the present invention has a high ballistic resistance per unit weight that cannot be achieved by a conventional woven fabric using the same high-strength high-elasticity fiber, and has a high strength and high elasticity. It has a structure of a laminate of these fibers that fully utilizes the performance of the fibers. Specifically, the bullet that passes through the bullet-resistant member is given a degree of freedom to sufficiently entangle the ultra-high-strength and high-elasticity fiber to increase the apparent bullet diameter, and the ultra-high that catches it. By increasing the weaving density of the woven fabric composed of high-strength and high-strength fibers, and preventing the displacement of the threads between the yarns against a large impact force locally, expanding the impact absorption range, and improving the ballistic performance The amount of deformation of the bulletproof member on the human body side can also be reduced to a range that does not affect the human body.
[0059]
Therefore, it not only has excellent ballistic performance per unit weight that could not be achieved with conventional fabrics, but also provides the same amount of deformation on the human body as the ballistic members that are equivalent to conventional fabrics, and a significant reduction in weight. It is possible to provide a bulletproof member having high safety as well as improved handleability.

Claims

A ballistic member having a porosity of 78% or more and 98% or less formed by stitching one woven fabric to at least one surface of a laminate composed of at least two short fiber nonwoven fabrics,
The background average fabric strength is comprised of short fibers of 10 mm or more and 150 mm or less made of ultra-high-strength high-elastic fibers having a single fiber strength of 18 g / d or more and a tensile modulus of 500 g / d or more. A short fiber nonwoven fabric of 0.05 kgf / 2 cm to 30 kgf / 2 cm,
The woven fabric is constituted by the ultra high strength and high elastic fiber, and is represented by the following formula (CF)

There is 1500 to 2,000 fabric, the percentage of the weight of said textile to the total weight of the resistant bullets member is 40 wt% or less than 3 wt%, ultra high strength and high elastic fibers constituting the fabric was A bulletproof member, which is a polyethylene fiber having a cross-sectional flatness of 1.5 to 12.0.