JP4357626B2 - UV shielding fabric - Google Patents

Description

ただし、（１）式中、λは紫外線の波長、Ｅλは基準紅斑効果値、Ｓλは基準太陽放射照度値、Ｔλは布帛の紫外線透過率（％）及び△λは測定波長間隔＝２ｎｍを表す。
【０００８】
本発明でいう開孔率とは、布帛に実質的にどの程度の面積割合の貫通孔があるかを示すものである。布帛の開口率とは、光学顕微鏡（倍率：５〜５０倍）により織編物等布帛の裏面から光をあてた状態で、開孔部が白、繊維部が黒になるような拡大写真を取り、写真の画像をＣＣＤカメラによりコンピューターに取り込み、画像処理ソフトにより取り込んだ画像を、色相差により白と黒に２値化した後、全体面積のうち白（開孔部）の面積割合を算出して得られる値である。
【０００９】
本発明のでいうＳＰＦ値とは布帛製品でカバーした皮膚の部分が、カバーしない皮膚よりどれくらい長く、日光に曝すことができるかを示す指標である。例えば、ＳＰＦ２０の織編物製品で皮膚をカバーすると、素肌の時よりも２０倍長く日光に暴露することができることを意味するものである。ここで、ＳＰＦは紫外線の波長毎の皮膚へのダメージを加味して紫外線遮蔽特性値であって、下記の式（１）を用いて算出される。
【００１０】

（１）式中、λは紫外線の波長、Ｅλは紅斑効果値、Ｓλは太陽放射照度値、Ｔλは布帛の紫外線透過率（％）及び△λは測定波長間隔＝２ｎｍをそれぞれ表す。
【００１１】
ここで紅斑効果値（Ｅλ）は、表１に示す紫外線波長毎に皮膚紅斑を効果する値である（Ｆｏｏｄ ａｎｄ Ｄｒｕｇ Ａｄｍｉｎｉｓｔｒａｔｉｏｎ，“Ｓｕｎｓｃｒｅｅｎ Ｄｒｕｇ Ｐｒｏｄｕｃｔｓ ｆｏｒ Ｏｖｅｒ−ｔｈｅ−Ｃｏｕｎｔｅｒ Ｈｕｍａｎ Ｕｓｅ；Ｔｅｎｔａｔｉｖｅ Ｆｉｎａｌ Ｍｏｎｏｇｒａｐｈ：Ｐｒｏｐｏｓｅｄ Ｒｕｌｅ，Ｆｅｄｅｒａｌ Ｒｅｇｉｓｔｅｒ ｖｏｌ５８，ｎｏ．９０．２１ ＣＦＲ Ｐａｒｔ ３５２ ｅｔ ａｌ，２８１９３−２８３０２より準用）。基準太陽放射照度値（Ｗ／ｃｍ² ／ｍｍ）は、第２表に示す６月の実際の太陽放射照度で表される（Ｓａｙｒｅ，Ｒ．ｌ．，Ｃｏｌｅ，Ｃ．，Ｂｉｌｌｈｉｍｅｒ，Ｗ．，Ｓｔａｎｆｉｅｌｄ，Ｊ．，ａｎｄ Ｌｅｙ，Ｒ．Ｄ．“Ｓｐｅｃｉａｌ Ｃｏｍｐａｒｉｓｏｎ ｏｆ Ｓｏｌａｒ Ｓｉｍｕｌａｔｏｒｓ ａｎｄ Ｓｕｎｌｉｇｈｔ，“Ｐｈｏｔｏｄｅｒｍａｔｏｌ．Ｐｈｏｔｏｉｍｍｕｎｏｌ ｐｈｏｔｏｍｅｄ．７：１・９ー１５９（１９９０）より準用）。
【００１２】
Ｔλは、布帛の紫外線透過率（％）で重水素ランプを光源とする紫外線分光光度計により測定される、紫外線波長毎の透過率の値である。
【００１３】
【表１】

【００１４】
【表２】

【００１５】
【発明の実施の形態】
以下本発明について詳細に説明する。
本発明において、布帛は織物、編物及び短繊維あるいはフィラメント繊維をシート状に形成させてウエブとし、ウエブ構成繊維を接着、絡合、スティッチボンド法等で固定して形成される不織布、及びこれらの積層布帛をいう。
【００１６】
本発明では、布帛の開孔率が０．５％以上７％以下であることが肝要である。開孔率が７％以下であることにより、皮膚に与えるダメージの大きい紫外線Ｂ波の遮蔽性が優れたものとなる。より好ましくは開孔率は５％以下である。開孔率が７％を越えると、無機酸化物微粒子の含有量の高い紫外線遮蔽性の高い繊維を用いて布帛を調製したとしても、より有害な紫外線Ｂ波の遮蔽性が劣り、皮膚の保護が不充分なものとなる。布帛のの開孔率が０．５％以上必要である。開孔率が０．５％未満になると織編物の風合いが硬くなると同時に、通気性が低下し清涼性に劣るものとなる。
【００１７】
本発明に用いられる布帛は、開孔率が０．５％以上７％以下であれば、織編物の組織は特に限定されるものではなく、単層であっても２層、３層あるいはそれ以上の層構造をしていてもよい。布帛が織物の場合、単層であれば例えば平織、綾織、朱子織等が、２層以上の構造であれば経二重織、緯二重織や多重織等任意に用いることができる。布帛が編物の場合、単層であれば天竺編、ゴム編等の緯編や、１枚筬の経編等が、２層以上の構造であれば、スムース、ポンチローマ等の緯編や、２枚筬以上の経編等任意に用いることができる。ポリウレタン等の弾性繊維と混用してストレッチ性を付与していてもよい。
【００１８】
さらに本発明の布帛が織物の場合、織物の見掛け密度が０．６ｃｍ³ 以下であることが好ましい。より好ましくは見掛け密度が０．５ｃｍ³ 以下である。見掛け密度が０．６ｃｍ³ を超えると織物の風合い、通気性が極端に低下し、硬く清涼性に劣るものとなってしまう。布帛が編物の場合、見掛け密度が０．２５ｃｍ³ 以下であることが好ましい。より好ましくは見掛け密度が０．２ｃｍ³ 以下である。見掛け密度が０．２５ｃｍ³ を超えると編物の風合い、通気性が極端に低下し、硬く清涼性に劣るものとなってしまう。
【００１９】
布帛が不織布である場合には、乾式、湿式法あるいはスパンボンド法により所定の開口率に調整した不織布構造を形成すればよい。
本発明の布帛は、無機酸化物微粒子の含有量が１．０重量％以上６．０重量％以下の合成繊維、及び／又は無機酸化物微粒子の含有量が３．０重量％以上２０．０重量％以下の芯部と、無機酸化物微粒子の含有量が２．０重量％以下の鞘部を有する芯鞘型合成繊維で構成されていることが必要である。
【００２０】
前記無機酸化物微粒子を含有する合成繊維は、例えば、ポリエステル系、ポリアミド系、アクリル系、ポリプロピレン系、ポリウレタン系等の合成繊維を用いることができるが、ポリエステル系、ポリアミド系、ポリプロピレン系等の溶融紡糸によって製造される合成繊維が製造工程上好ましい。
含有する無機酸化物微粒子は、原糸製造に障害を及ぼさなければ、その種類は特に限定されないが、例えば酸化チタン、酸化亜鉛、酸化マグネシウム、炭酸カルシウム、硫酸バリウム等を用いることができる。これらの無機酸化物微粒子は、単独もしくは２種以上を併用して用いることができる。使用される無機酸化物微粒子の平均粒径は、一般に、約１ミクロン以下であることが好ましい。約２ミクロン以上の粗大粒子になると、紡糸時の糸切れにつながり好ましくない。より好ましくは０．５ミクロン以下である。
【００２１】
無機酸化物微粒子の含有量は、芯鞘型でない単一のポリマー組成からなる合成繊維の場合、１．０重量％以上６．０重量％以下であることが必要である。含有量が１．０重量％未満では紫外線特にＡ波の遮蔽性が劣るものとなり、６．０重量％を越えると紡糸工程の安定性、製織製編工程性が著しく低下する。又、芯鞘型合成繊維の場合は、芯部の無機酸化物微粒子の含有量が３．０重量％以上２０．０重量％以下であることが必要である。含有量が３．０重量％未満では紫外線特にＡ波の遮蔽性が劣るものとなり、２０．０重量％を越えると微粒子の均一な分散が困難となり、紡糸時の糸切れなどの問題が生じる。好ましい含有量は５重量％〜１５重量％である。
【００２２】
芯鞘型合成繊維の場合、芯部と鞘部は同一のポリマー組成であっても、異なるポリマー組成であってもよい。例えばポリエステル芯鞘型合成繊維の場合、鞘部のみが共重合ポリエステルであってもよい。また、ポリアミド芯鞘型合成繊維の場合、芯部がナイロン６６で鞘部がナイロン６であってもよい。
また、芯部と鞘部は同心円状に複合されていてもよく、偏心して複合されていてもよい。芯成分の鞘成分に対する重量比は１／４〜４／１の範囲が好ましい。芯成分の重量比が１／４未満であると紫外線遮蔽効果が劣るものとなり、４／１を越えると紡糸時に芯成分がフィラメントの表面に露出し、安定した芯鞘形状が難しくなる。好ましい芯鞘比は１／２〜２／１であり、さらに好ましくは１／１である。
【００２３】
また、無機酸化物微粒子を含有する合成繊維の断面形状は特に限定されるものでなく、丸形、三角、Ｙ型、Ｌ型、Ｗ型、扁平、ドッグボーン型、多葉型等何れの形状であっても良い。また、繊維の形態は長繊維でも短繊維でも良く、長さ方向に均一なものや太細のあるものでもよい。さらには、長繊維に仮撚等の捲縮加工、流体噴射加工、撚糸等の加工が施されたものでもよい。
【００２４】
本発明で使用する合成繊維の繊度は、特に限定されるものではないが、衣料用として用いることを考慮するとトータルデニールは２０ｄ〜３００ｄ、単糸デニールは０．５ｄ〜１０ｄ程度が望ましい範囲である。特に過酷な条件にも耐え得なければならないスポーツ衣料用布帛の場合には、１ｄ〜５ｄがより望ましく、柔らかな肌触りや風合いを重視するインナー衣料用布帛の場合には、０．５ｄ〜３ｄがより望ましい。
【００２５】
また、本発明の布帛は本発明の目的を損なわない範囲内で、無機酸化物微粒子を含有した合成繊維と、他の繊維が混用されていても良い。
他の繊維にはポリエステル、ポリアミド、ポリウレタン、アクリル等の合成繊維や、綿、麻、ウール等の天然繊維等が好ましく用いられるが、任意の繊維を用いることができる。
【００２６】
混用の方法は、混紡、エアー混繊、交撚、複合仮撚（伸度差仮撚等）等の手段で糸複合で混用したり、交編や交織等により混用することができる。交編や交織の場合、経糸または緯糸の少なくと一方に用いたり、１本交互や２本交互等で配置したり、２層、３層等で配置する方法等で混用することができる。
しかしながら他の繊維と混用する場合は、紫外線遮蔽性を低下させないために、無機酸化物微粒子を含有した合成繊維の重量混率が、布帛の重量の３０％以上であることが好ましい。より好ましくは４０％以上である。また、布帛が織編物構造物である場合には、１本交互や２本交互等の様に周期的に織編物に配置されているか、織編物の１層全面に配置されていることが好ましい。
【００２７】
さらに本発明の布帛は、ＳＰＦ値が２０以上、より好ましくはＳＰＦ値は３０以上、さらに好ましくは５０以上が望ましい。ＳＰＦの値が２０以上であることにより、紫外線から皮膚を保護する効果が十分なものとなるが、ＳＰＦの値が２０未満では、日焼け等、皮膚の受けるダメージが大きいものとなる。
【００２８】
【実施例】
本発明を実施例により更に具体的に説明するが、本発明は実施例に限定されるものではない。
なお、実施における布帛の性量、物性は下記の方法を用いて測定、評価し、表３にまとめて示す。
（１）厚みの測定
厚み計により５ｇ／ｃｍ² 荷重における織編物の厚み（ｍｍ）を測定する。
（２）見掛け密度の測定
織編物の目付（ｇ／ｍ² ）と厚み（ｍｍ）の関係から以下にて算出する。
【００２９】
見掛け密度（ｇ／ｃｍ² ）＝目付（ｇ／ｍ² ）／厚み（ｍｍ）／１０００
（３）通気性の測定
ＪＩＳ−Ｌ−１０９６フラジール法に準じて通気度（ｃｃ／ｃｍ² ／ｓｅｃ）を測定する。
（４）紫外線遮蔽性の測定
作製した織編物をタテ４ｃｍ×ヨコ１０ｃｍにカットし、これらを一度に左右の太股部に張り付け、８月の太陽光下でテニスをしながら累計５時間太陽光に暴露し、日焼けの程度を以下判定基準にて評価した。評価結果は表３にまとめた。
【００３０】
◎：全く皮膚に変化が見られない
○：殆ど皮膚に変化が見られない
△：皮膚にやや赤みが発生
×：皮膚にかなり赤みが発生
（５）風合いの評価
作製した織編物の風合いを以下判定基準にて官能評価した。
【００３１】
○：風合いが柔らかく良好
×：風合いが硬く不良
〔参考例１〕
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）を経糸及び緯糸に用い平織物を作製し、精練後、１８０℃乾熱で熱セットを施し、経糸密度１２４本／インチ、緯糸密度８７本／インチ、厚み０．１３ｍｍ、目付７１ｇ／ｍ²、見掛け密度０．５５ｇ／ｃｍ³の織物を得た。織物の開孔率は１．５％で、ＳＰＦ値は１５０であった。この織物は紫外線による日焼けを防止し風合いも柔らかく、また、通気性が高く清涼性に優れる織物であった。
【００３２】
［参考例２］
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（５０デニール３６フィラメント）を経糸及び緯糸に用い平織物を作製し、精練、３０％のアルカリ減量を行った後、１８０℃乾熱セットを施し、経糸密度１７２本／インチ、緯糸密度１２１本／インチ、厚み０．１ｍｍ、目付４９ｇ／ｍ²、見掛け密度０．４９ｇ／ｃｍ³の織物を得た。この織物の開孔率は、４．０％でＳＰＦ値は５０で、紫外線による日焼けを防止し、風合いも柔らかく、また、通気性が非常に高く清涼性に優れる織物であった。
【００３３】
［参考例３］
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）を経糸に用い、緯糸に酸化チタンを０．１重量％含有するポリエステル丸断面糸（７５デニール３６フィラメント）を用い平織物を作製し、実施例１と同様の精練・乾熱セットを施し、経糸密度１４７本／インチ、緯糸密度８５本／インチ、厚み０．１３、目付７３ｇ／ｍ²、見掛け密度０．５６ｇ／ｃｍ³の織物を得た。織物の開孔率は１．１％、ＳＰＦ値は３１であった。この織物は紫外線による日焼けを防止し風合いも柔らかく、また、通気性が高く清涼性に優れる織物であった。
【００３４】
［参考例４］
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）と、酸化チタンを０．１重量％含有するポリエステル繊維（７５デニール３６フィラメント）を１本交互で経糸及び緯糸に用い平織物を作製し、実施例１と同様の精練・乾熱セットを施し、経糸密度１２４本／インチ、緯糸密度８７本／インチ、厚み０．１２ｍｍ、目付６７ｇ／ｍ²、見掛け密度０．５６ｇ／ｃｍ³の織物を得た。織物の開孔率は１．３％、ＳＰＦ値は３１であった。この織物は紫外線による日焼けを防止することができ、風合いも柔らかく、また、通気性が高く清涼性に優れる織物であった。
【００３５】
［参考例５］
酸化チタンを２．０重量％含有するポリエステル繊維（７５デニール３６フィラメントを経糸及び緯糸に用い平織物を作製し、実施例１と同様の精練・乾熱セットを施し、経糸密度１４７本／インチ、緯糸密度８５本／インチ、厚み０．１２、目付６９ｇ／ｍ²、見掛け密度０．５８ｇ／ｃｍ³の織物を得た。織物の開孔率は１．５％、ＳＰＦ値は９８であった。この織物は紫外線による日焼けを防止し風合いも柔らかく、また、通気性が高く清涼性に優れる織物であった。
【００３６】
［実施例１］
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）を、三菱ＬＳ−２仮撚機にて、スピンドル回転数２５万ｒｐｍ、撚数３２００Ｔ／ｍ、ファーストヒーター温度２００℃、セカンドヒーター温度１９０℃で仮撚加工した糸を用い、２８Ｇシングル丸編機にて天竺編地を作製し、精練後、１８０℃乾熱セットを施し、３８コース／インチ、３７ウエール／インチ、厚み０．７８ｍｍ、目付１３０ｇ／ｍ²、見掛け密度０．１７ｇ／ｃｍ³の編物を得た。編物の開孔率は４．５％で、ＳＰＦ値は３１であった。編物は紫外線による日焼けを防止することができ、風合いも柔らかく、また、通気性が極めて高く清涼性に優れる編物であった。
【００３７】
〔比較例１〕
酸化チタンを２．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）を経糸及び緯糸に用い平織物を作製し、精練後、１８０℃乾熱で熱セットを施し、経糸密度１２４本／インチ、緯糸密度８７本／インチ、厚み０．１３ｍｍ、目付６８ｇ／ｍ² 、見掛け密度０．５２ｇ／ｃｍ³ の織物を得た。織物の開孔率は１．１％で、ＳＰＦ値は１９であった。この織物は風合いは柔らかく通気性が高いものの、紫外線による日焼け防止効果が充分ではなかった。
【００３８】
〔比較例２〕
酸化チタンを０．１重量％含有するポリエステル繊維（７５デニール３６フィラメントを経糸及び緯糸に用い平織物を作製し、実施例１と同様の精練・乾熱セットを施し、経糸密度１４７本／インチ、緯糸密度８５本／インチ、厚み０．１２ｍｍ、目付７１ｇ／ｍ² 、見掛け密度０．５９ｇ／ｃｍ³ の織物を得た。織物の開孔率は１．５％、ＳＰＦ値は１８であった。織物は風合いは柔らかく通気性が高いものの、紫外線による日焼け防止効果が充分なものではなかった。
【００３９】
〔比較例３〕
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（５０デニール３６フィラメント）を経糸及び緯糸に用い平織物を作製し、精練、４９％のアルカリ減量を行った後、１８０℃乾熱セットを施し、経糸密度１７２本／インチ、緯糸密度１２１本／インチ、厚み０．０８ｍｍ、目付３６ｇ／ｍ² 、見掛け密度０．４５ｇ／ｃｍ³ の織物を得た。本織物の開孔率は、７．３％でＳＰＦ値は１７であった。この織物は風合いは柔らかく通気性が非常に高いものの、紫外線による日焼け防止効果が充分ではなかった。
【００４０】
〔比較例４〕
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント）を経糸及び緯糸に用い平織物を作製し、精練後、１８０℃乾熱で熱セットを施し、経糸密度１４３本／インチ、緯糸密度１０３本／インチ、厚み０．１６ｍｍ、目付９７ｇ／ｍ² 、見掛け密度０．６１ｇ／ｃｍ³ の織物を得た。織物の開孔率は、０．４％で、ＳＰＦ値は１９３であった。この織物は紫外線による日焼けを防止できるが、風合いが硬く通気性の低い織物であった。
【００４１】
〔比較例５〕
酸化チタンを０．１重量％含有するポリエステル繊維（７５デニール３６フィラメント）を、実施例６と同一条件で仮撚加工した糸を用い、２８Ｇシングル丸編機にて天竺編地を作製し、精練後、１８０℃乾熱セットを施し、３６コース／インチ、３７ウエール／インチ、厚み０．７６ｍｍ、目付１２９ｇ／ｍ² 、見掛け密度０．１７ｇ／ｃｍ³ の編物を得た。編物の開孔率は、４．９％で、ＳＰＦ値は１６であった。
【００４２】
本編物は風合いは柔らかく通気性が極めて高いものの、紫外線による日焼け防止効果が充分でない編物であった。
〔比較例６〕
酸化チタンを８．０重量％含有する芯部と、酸化チタンを０．０５重量％含有する鞘部からなり、芯鞘重量比率１／１である同心円状のポリエステル芯鞘型合成繊維（７５デニール３６フィラメント原糸）を用い、２８Ｇシングル丸編機にて天竺編地を作製し、精練後、１８０℃乾熱セットを施し、３４コース／インチ、４１ウエール／インチ、厚み０．６１ｍｍ、目付１２０ｇ／ｍ² 、見掛け密度０．２０ｇ／ｃｍ³ の編物を得た。編物の開孔率は、７．７％で、ＳＰＦ値は１４であった。この編物は風合いは柔らかく通気性が極めて高いものの、紫外線による日焼け防止効果が十分でない編物であった。
【００４３】
〔比較例７〕
実施例６と同一の仮撚加工糸を用い、２８Ｇシングル丸編機にて天竺編地を作製し、精練後、１８０℃乾熱セットを施し、５８コース／インチ、４１ウエール／インチ、厚み０．６７ｍｍ、目付１７５ｇ／ｍ² 、見掛け密度０．２６ｇ／ｃｍ³ の編物を得た。編物の開孔率は、０．３％で、ＳＰＦ値は１１０であった。この編物は紫外線による日焼けを防止できるが、風合いが硬く通気性の低い編物であった。
【００４４】
【表３】

【００４５】
【発明の効果】
本発明の布帛は、紫外線Ａ波の遮蔽性を向上すると共に、特に皮膚に有害な紫外線Ｂ波の遮蔽性を向上させ、紫外線による皮膚ダメージを大幅に低減することができる。また、風合いが柔らかくかつ高通気性で清涼性に優れたものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fabric used for sports, inner, outer and other clothing applications and umbrellas, curtains and other material applications having excellent ultraviolet shielding properties, soft texture, high air permeability and excellent refreshing properties.
[0002]
[Prior art]
Conventionally, many fabrics with improved ultraviolet shielding properties have been proposed for the purpose of preventing sunburn, stains, skin cancer and the like due to ultraviolet rays.
For example, Japanese Patent Application Laid-Open No. 5-148734 discloses a fabric that contains an ultraviolet reflection or an absorbent, regulates the transmittance of ultraviolet A waves (320 to 400 μm) and ultraviolet B waves (290 to 320 μm), and maintains high air permeability. Has been proposed. In this prior art, the ultraviolet shielding property is improved by dividing the ultraviolet A wave and the B wave, which have different degrees of influence on sunburn and skin damage, and suppressing the respective average transmittances below a certain value. However, in actual sunlight, the degree of influence on sunburn and skin damage varies depending on the wavelength among ultraviolet A wave and B wave. Therefore, skin damage for each wavelength is considered only by the average transmittance regulation for A wave and B wave. The fabric is not sufficient to prevent actual sunburn.
[0003]
Japanese Laid-Open Patent Publication No. 61-146840 discloses a woven fabric having a cover factor of a certain level or more. However, a fabric with a high cover factor and a dense fabric has a hard fabric texture and air permeability. It had the disadvantage of being lowered and having a refreshing feeling.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a fabric that can solve the above-mentioned problems and can protect the skin from sunburn and blemishes caused by ultraviolet rays that have a soft texture and are highly breathable and have a refreshing feeling.
[0005]
[Means for Solving the Problems]
The inventors of the present invention selectively specified the porosity and the apparent density of a fabric made of synthetic fibers containing inorganic oxide fine particles in a specific manner, and controlled the ultraviolet transmission intensity of the fabric. The present invention has found that a fabric can be obtained that protects skin from sunburn, spots, etc., has a soft texture, is highly breathable and has a refreshing feeling, and can protect skin from sunburn, spots, etc. It was.
[0006]
The present invention provides a synthetic fiber having a content of inorganic oxide fine particles of 1.0 wt% or more and 6.0 wt% or less, and / or a content of inorganic oxide fine particles of 3.0 wt% or more and 20.0 wt%. A fabric composed of a core-sheath type synthetic fiber having the following core part and a sheath part having a content of inorganic oxide fine particles of 2.0% by weight or less, and the fabric has a porosity of 0.5% or more and 7 % Or less, and the SPF value shown in the following formula (1) is 20 or more.
[0007]

However, in the formula (1), λ is the wavelength of ultraviolet rays, Eλ is the reference erythema effect value, Sλ is the reference solar irradiance value, Tλ is the ultraviolet transmittance (%) of the fabric, and Δλ is the measurement wavelength interval = 2 nm. .
[0008]
The open area rate as used in the present invention indicates how much of the through-hole is substantially in the fabric. The aperture ratio of the fabric is an enlarged photograph in which the aperture is white and the fiber is black when light is applied from the back of the fabric such as woven or knitted fabric with an optical microscope (magnification: 5 to 50 times). After taking a photograph image into a computer with a CCD camera and binarizing the image taken with the image processing software into white and black based on the hue difference, the area ratio of white (open hole) in the total area is calculated. Is the value obtained.
[0009]
The SPF value referred to in the present invention is an index indicating how long the portion of the skin covered with the fabric product can be exposed to sunlight than the uncovered skin. For example, if the skin is covered with a woven or knitted product of SPF20, it means that it can be exposed to sunlight 20 times longer than when it is bare skin. Here, SPF is an ultraviolet shielding characteristic value in consideration of damage to the skin for each wavelength of ultraviolet rays, and is calculated using the following formula (1).
[0010]

In the formula (1), λ represents the wavelength of ultraviolet rays, Eλ represents the erythema effect value, Sλ represents the solar irradiance value, Tλ represents the ultraviolet transmittance (%) of the fabric, and Δλ represents the measurement wavelength interval = 2 nm.
[0011]
Here, the erythema effect value (Eλ) is a value that affects skin erythema for each ultraviolet wavelength shown in Table 1 (Food and Drug Administration, “Sunscreen Drug Products for Over-the-Counter Human Human Use; Rule, Federal Register vol 58, no. 90.21 CFR Part 352 et al, 28193-28302. Reference solar irradiance value (W / cm ² / mm) is the actual sun for June shown in Table 2. It is expressed in terms of irradiance (Sayre, R.I., Cole, C., Billheimer, W., Stanfield, J., and Ley, R.D. “Special Com. arison of Solar Simulators and Sunlight, "Photodermatol.Photoimmunol photomed.7: apply mutatis mutandis than 1, 9-1 159 (1990)).
[0012]
Tλ is a value of transmittance for each ultraviolet wavelength measured by an ultraviolet spectrophotometer using a deuterium lamp as a light source, based on the ultraviolet transmittance (%) of the fabric.
[0013]
[Table 1]

[0014]
[Table 2]

[0015]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
In the present invention, the fabric is a non-woven fabric formed by forming a woven fabric, a knitted fabric and short fibers or filament fibers into a sheet to form a web, and fixing the web constituent fibers by adhesion, entanglement, stitch bond method, and the like. This refers to a laminated fabric.
[0016]
In the present invention, it is important that the open area ratio of the fabric is 0.5% or more and 7% or less. When the open area ratio is 7% or less, the shielding property of ultraviolet B wave having a large damage to the skin is excellent. More preferably, the hole area ratio is 5% or less. When the open area ratio exceeds 7%, even if a fabric is prepared using a fiber having a high content of inorganic oxide fine particles and a high ultraviolet shielding property, the shielding property of the more harmful ultraviolet B wave is inferior and the skin is protected. Is insufficient. The opening ratio of the fabric needs to be 0.5% or more. When the open area ratio is less than 0.5%, the texture of the woven or knitted fabric becomes hard, and at the same time, the air permeability is lowered and the coolness is inferior.
[0017]
The fabric used in the present invention is not particularly limited in the structure of the woven or knitted fabric as long as the open area ratio is 0.5% or more and 7% or less. You may have the above layer structure. When the fabric is a woven fabric, a plain weave, twill weave, satin weave, or the like can be used as long as it is a single layer. If the fabric is a knitted fabric, if it is a single layer, weft knitting such as tengu knitting, rubber knitting, etc., if a single sheet warp knitting, etc. is a structure of two or more layers, weft knitting such as smooth, ponchiroma, etc. Two or more warp knitting etc. can be used arbitrarily. It may be mixed with elastic fibers such as polyurethane to give stretch properties.
[0018]
Furthermore, when the fabric of the present invention is a woven fabric, the apparent density of the woven fabric is preferably 0.6 cm ³ or less. More preferably, the apparent density is 0.5 cm ³ or less. When the apparent density exceeds 0.6 cm ³ , the texture and breathability of the fabric is extremely lowered, and it becomes hard and inferior in coolness. When the fabric is a knitted fabric, the apparent density is preferably 0.25 cm ³ or less. More preferably, the apparent density is 0.2 cm ³ or less. If the apparent density exceeds 0.25 cm ³ , the texture and air permeability of the knitted fabric will be extremely lowered, and it will be hard and inferior in coolness.
[0019]
When the fabric is a nonwoven fabric, a nonwoven fabric structure adjusted to a predetermined opening ratio may be formed by a dry method, a wet method, or a spunbond method.
In the fabric of the present invention, the content of the inorganic oxide fine particles is 1.0 wt% or more and 6.0 wt% or less, and / or the content of the inorganic oxide fine particles is 3.0 wt% or more and 20.0 wt%. It is necessary to be comprised with the core-sheath-type synthetic fiber which has a core part of weight% or less and a sheath part whose content of inorganic oxide fine particles is 2.0 weight% or less.
[0020]
As the synthetic fiber containing the inorganic oxide fine particles, for example, polyester-based, polyamide-based, acrylic-based, polypropylene-based, and polyurethane-based synthetic fibers can be used. Synthetic fibers produced by spinning are preferred in the production process.
The kind of inorganic oxide fine particles to be contained is not particularly limited as long as the production of the raw yarn is not hindered. For example, titanium oxide, zinc oxide, magnesium oxide, calcium carbonate, barium sulfate and the like can be used. These inorganic oxide fine particles can be used alone or in combination of two or more. In general, the average particle size of the inorganic oxide fine particles used is preferably about 1 micron or less. Coarse particles of about 2 microns or more are undesirable because they lead to yarn breakage during spinning. More preferably, it is 0.5 micron or less.
[0021]
In the case of a synthetic fiber having a single polymer composition that is not a core-sheath type, the content of the inorganic oxide fine particles needs to be 1.0% by weight or more and 6.0% by weight or less. When the content is less than 1.0% by weight, the shielding property against ultraviolet rays, particularly A waves, is inferior. When the content exceeds 6.0% by weight, the stability of the spinning process and the weaving and knitting processability are significantly deteriorated. In the case of the core-sheath type synthetic fiber, the content of the inorganic oxide fine particles in the core part is required to be 3.0% by weight or more and 20.0% by weight or less. When the content is less than 3.0% by weight, the shielding property of ultraviolet rays, particularly A waves, is inferior. When the content exceeds 20.0% by weight, uniform dispersion of fine particles becomes difficult, and problems such as yarn breakage during spinning occur. A preferable content is 5 to 15% by weight.
[0022]
In the case of the core-sheath type synthetic fiber, the core part and the sheath part may have the same polymer composition or different polymer compositions. For example, in the case of a polyester core-sheath type synthetic fiber, only the sheath part may be a copolyester. In the case of a polyamide core-sheath type synthetic fiber, the core may be nylon 66 and the sheath may be nylon 6.
Moreover, the core part and the sheath part may be combined concentrically, or may be eccentrically combined. The weight ratio of the core component to the sheath component is preferably in the range of 1/4 to 4/1. When the weight ratio of the core component is less than 1/4, the ultraviolet shielding effect is inferior, and when it exceeds 4/1, the core component is exposed on the surface of the filament during spinning, and a stable core-sheath shape becomes difficult. A preferred core / sheath ratio is 1/2 to 2/1, more preferably 1/1.
[0023]
In addition, the cross-sectional shape of the synthetic fiber containing the inorganic oxide fine particles is not particularly limited, and any shape such as a round shape, a triangular shape, a Y shape, an L shape, a W shape, a flat shape, a dogbone shape, and a multileaf shape. It may be. Further, the form of the fibers may be long fibers or short fibers, and may be uniform or thick in the length direction. Further, the long fiber may be subjected to crimping processing such as false twisting, fluid injection processing, and twisting yarn processing.
[0024]
The fineness of the synthetic fiber used in the present invention is not particularly limited, but considering that it is used for clothing, the total denier is preferably 20d to 300d, and the single yarn denier is preferably about 0.5d to 10d. . In the case of a fabric for sports clothing that must be able to withstand particularly harsh conditions, 1d to 5d is more desirable, and in the case of a fabric for inner clothing that places an emphasis on soft touch and texture, 0.5d to 3d. More desirable.
[0025]
In the fabric of the present invention, synthetic fibers containing inorganic oxide fine particles and other fibers may be mixed within a range not impairing the object of the present invention.
For other fibers, synthetic fibers such as polyester, polyamide, polyurethane, and acrylic, and natural fibers such as cotton, hemp, and wool are preferably used, but any fibers can be used.
[0026]
The mixing method can be mixed with yarn composite by means of blending, air mixing, cross twist, composite false twist (elongation difference false twist, etc.), or can be mixed by cross knitting or cross weaving. In the case of knitting or weaving, it can be used for at least one of warp or weft, or can be mixed by one or two or alternately, or by two or three layers.
However, when mixed with other fibers, the weight mixing ratio of the synthetic fibers containing the inorganic oxide fine particles is preferably 30% or more of the weight of the fabric in order not to lower the ultraviolet shielding property. More preferably, it is 40% or more. Further, when the fabric is a woven or knitted structure, it is preferable that the cloth is periodically arranged on the knitted or knitted fabric, such as alternately or alternately, or on the entire surface of the woven or knitted fabric. .
[0027]
Furthermore, the fabric of the present invention has an SPF value of 20 or more, more preferably an SPF value of 30 or more, and even more preferably 50 or more. When the SPF value is 20 or more, the effect of protecting the skin from ultraviolet rays is sufficient, but when the SPF value is less than 20, damage to the skin such as sunburn becomes large.
[0028]
【Example】
The present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.
In addition, the physical quantity and physical property of the fabric in the implementation are measured and evaluated using the following methods, and are summarized in Table 3.
(1) Measurement of thickness The thickness (mm) of the woven or knitted fabric at a load of 5 g / cm ² is measured with a thickness meter.
(2) Measurement of apparent density The apparent density is calculated from the relationship between the basis weight (g / m ² ) and thickness (mm) of the woven or knitted fabric.
[0029]
Apparent density (g / cm ² ) = weight per unit area (g / m ² ) / thickness (mm) / 1000
(3) Measurement of air permeability The air permeability (cc / cm ² / sec) is measured according to JIS-L-1096 Frazier method.
(4) Measurement of UV shielding property The produced woven or knitted fabric is cut into 4cm x 10cm vertically, and these are attached to the left and right thighs at the same time. After exposure, the degree of sunburn was evaluated according to the following criteria. The evaluation results are summarized in Table 3.
[0030]
◎: No change in skin is observed. ○: Almost no change is observed in skin. △: Slight redness is generated in the skin. X: Considerable redness is generated in the skin. (5) Evaluation of texture The texture of the prepared knitted fabric is as follows. Sensory evaluation was performed according to the criteria.
[0031]
○: Soft and soft texture ×: Hard and poor texture [ Reference Example 1]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used for warp and weft, and after scouring, heat set by dry heat at 180 ° C., warp density 124 / inch, weft density 87 / inch, thickness 0.13 mm, basis weight 71 g / A woven fabric of m ² and an apparent density of 0.55 g / cm ³ was obtained. The open area ratio of the woven fabric was 1.5%, and the SPF value was 150. This fabric was a fabric that prevented sunburn by ultraviolet rays, had a soft texture, and had high air permeability and excellent coolness.
[0032]
[ Reference Example 2]
Concentric polyester core-sheath type synthetic fiber (50 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used for warp and weft, scoured and subjected to 30% alkali weight reduction, then 180 ° C dry heat set, warp density 172 / inch, weft density 121 / inch, thickness A woven fabric having a size of 0.1 mm, a basis weight of 49 g / m ² , and an apparent density of 0.49 g / cm ³ was obtained. This fabric had a porosity of 4.0% and an SPF value of 50, which prevented sunburn caused by ultraviolet rays, had a soft texture, and had a very high air permeability and excellent coolness.
[0033]
[ Reference Example 3]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used as warp yarns and plain weave fabrics are produced using polyester round cross-section yarns (75 denier 36 filaments) containing 0.1% by weight of titanium oxide as weft yarns. As a result, a woven fabric having a warp density of 147 yarns / inch, a weft density of 85 yarns / inch, a thickness of 0.13, a basis weight of 73 g / m ² , and an apparent density of 0.56 g / cm ³ was obtained. The open area ratio of the woven fabric was 1.1%, and the SPF value was 31. This fabric was a fabric that prevented sunburn by ultraviolet rays, had a soft texture, and had high air permeability and excellent coolness.
[0034]
[ Reference Example 4]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) and polyester fibers containing 0.1% by weight of titanium oxide (75 denier 36 filaments) are alternately used for warp and weft to produce a plain woven fabric, and the same scouring and dry heat set as in Example 1 Thus, a woven fabric having a warp density of 124 / inch, a weft density of 87 / inch, a thickness of 0.12 mm, a basis weight of 67 g / m ² , and an apparent density of 0.56 g / cm ³ was obtained. The open area ratio of the woven fabric was 1.3%, and the SPF value was 31. This fabric was able to prevent sunburn due to ultraviolet rays, had a soft texture, and had high breathability and excellent cooling properties.
[0035]
[ Reference Example 5]
Polyester fiber containing 2.0% by weight of titanium oxide (a plain woven fabric is produced using 75 denier 36 filaments for warp and weft, and subjected to the same scouring and dry heat setting as in Example 1, with a warp density of 147 yarns / inch, A woven fabric having a weft density of 85 yarns / inch, a thickness of 0.12, a basis weight of 69 g / m ² , and an apparent density of 0.58 g / cm ³ was obtained, and the woven fabric had a porosity of 1.5% and an SPF value of 98. This fabric was a fabric that prevented sunburn caused by ultraviolet rays, had a soft texture, and had high air permeability and excellent coolness.
[0036]
[Example 1 ]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filament) using a Mitsubishi LS-2 false twisting machine and a 28G single using a false twisted yarn with a spindle rotation speed of 250,000 rpm, a twisting speed of 3200 T / m, a first heater temperature of 200 ° C., and a second heater temperature of 190 ° C. Tendon knitted fabric is prepared with a circular knitting machine, and after scouring, 180 ° C. dry heat set is applied, 38 course / inch, 37 wale / inch, thickness 0.78 mm, basis weight 130 g / m ² , apparent density 0.17 g / A knitted fabric of cm ³ was obtained. The hole ratio of the knitted fabric was 4.5%, and the SPF value was 31. The knitted fabric was able to prevent sunburn due to ultraviolet rays, had a soft texture, and had extremely high air permeability and excellent coolness.
[0037]
[Comparative Example 1]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 2.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used as warps and wefts to produce a plain woven fabric, and after scouring, heat setting is performed by dry heat at 180 ° C., warp density of 124 yarns / inch, weft density of 87 yarns / inch, thickness of 0.13 mm, basis weight of 68 g / A fabric with m ² and an apparent density of 0.52 g / cm ³ was obtained. The open area ratio of the woven fabric was 1.1%, and the SPF value was 19. This fabric had a soft texture and high air permeability, but was not sufficiently effective in preventing sunburn by ultraviolet rays.
[0038]
[Comparative Example 2]
Polyester fiber containing 0.1% by weight of titanium oxide (a plain woven fabric is prepared using 75 denier 36 filaments for warp and weft, and subjected to the same scouring and dry heat setting as in Example 1, with a warp density of 147 yarns / inch, A woven fabric having a weft density of 85 yarns / inch, a thickness of 0.12 mm, a basis weight of 71 g / m ² , and an apparent density of 0.59 g / cm ³ was obtained, and the woven fabric had an aperture ratio of 1.5% and an SPF value of 18. Although the fabric has a soft texture and high air permeability, the sunscreen effect by ultraviolet rays is not sufficient.
[0039]
[Comparative Example 3]
Concentric polyester core-sheath type synthetic fiber (50 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used for warp and weft to produce a plain woven fabric, scoured and subjected to alkali weight reduction of 49%, followed by 180 ° C dry heat setting, warp density of 172 yarns / inch, weft density of 121 yarns / inch, thickness A woven fabric having a weight of 0.08 mm, a basis weight of 36 g / m ² and an apparent density of 0.45 g / cm ³ was obtained. The open area ratio of the woven fabric was 7.3%, and the SPF value was 17. This fabric had a soft texture and very high air permeability, but did not have sufficient sun protection effect due to ultraviolet rays.
[0040]
[Comparative Example 4]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filaments) are used for warp and weft, and after scouring, heat setting is performed by dry heat at 180 ° C., warp density is 143 / inch, weft density is 103 / inch, thickness is 0.16 mm, basis weight is 97 g / A woven fabric of m ² and an apparent density of 0.61 g / cm ³ was obtained. The open area ratio of the woven fabric was 0.4%, and the SPF value was 193. Although this fabric can prevent sunburn by ultraviolet rays, it is a fabric with a hard texture and low air permeability.
[0041]
[Comparative Example 5]
Using a yarn obtained by false twisting a polyester fiber (75 denier 36 filaments) containing 0.1% by weight of titanium oxide under the same conditions as in Example 6, a tengu knitted fabric was prepared with a 28G single circular knitting machine and scoured Thereafter, a 180 ° C. dry heat set was applied to obtain a knitted fabric of 36 courses / inch, 37 wales / inch, thickness 0.76 mm, basis weight 129 g / m ² , and apparent density 0.17 g / cm ³ . The hole ratio of the knitted fabric was 4.9%, and the SPF value was 16.
[0042]
This knitted fabric was a knitted fabric that had a soft texture and extremely high air permeability but did not have sufficient sun protection effect due to ultraviolet rays.
[Comparative Example 6]
Concentric polyester core-sheath type synthetic fiber (75 denier) having a core part containing 8.0% by weight of titanium oxide and a sheath part containing 0.05% by weight of titanium oxide and having a core-sheath weight ratio of 1/1. 36 filament yarn) and a 28G single circular knitting machine to prepare a woven fabric, and after scouring, it is subjected to a 180 ° C dry heat set, 34 courses / inch, 41 wales / inch, thickness 0.61 mm, basis weight 120 g / M ² and an apparent density of 0.20 g / cm ³ were obtained. The hole ratio of the knitted fabric was 7.7%, and the SPF value was 14. This knitted fabric was a knitted fabric that had a soft texture and extremely high air permeability but did not have sufficient sun protection effect due to ultraviolet rays.
[0043]
[Comparative Example 7]
Using the same false twisted yarn as in Example 6, a tengu knitted fabric was produced with a 28G single circular knitting machine, and after scouring, it was subjected to 180 ° C. dry heat setting, 58 courses / inch, 41 wales / inch, thickness 0 A knitted fabric having a diameter of .67 mm, a basis weight of 175 g / m ² , and an apparent density of 0.26 g / cm ³ was obtained. The hole ratio of the knitted fabric was 0.3%, and the SPF value was 110. Although this knitted fabric can prevent sunburn due to ultraviolet rays, it is a knitted fabric with a hard texture and low air permeability.
[0044]
[Table 3]

[0045]
【The invention's effect】
The fabric of the present invention improves the shielding ability of ultraviolet A waves, improves the shielding ability of ultraviolet B waves particularly harmful to the skin, and can greatly reduce skin damage due to ultraviolet rays. In addition, it has a soft texture, high air permeability, and excellent coolness.

Claims (1)

Synthetic fibers having a content of inorganic oxide fine particles of 1.0% by weight to 6.0% by weight and / or a core having a content of inorganic oxide fine particles of 3.0% by weight to 20.0% by weight When a knitted fabric composed of core-sheath synthetic fibers content of the inorganic oxide fine particles having a sheath of 2.0 wt% or less, porosity of knitting 5% or more and 0.5% or less, knitted an apparent density of 0.25 g / cm ³ or less of, and below (1) ultraviolet shielding of knitted fabric and wherein the SPF value shown in the expression of 20 or more.

In the formula, λ represents the wavelength of ultraviolet rays, Eλ represents a reference erythema effect value, Sλ represents a reference solar irradiance value, Tλ represents an ultraviolet transmittance (%) of the knitted fabric, and Δλ represents a measurement wavelength interval = 2 nm.