JP3805052B2

JP3805052B2 - Anti-discoloration mixed fabric

Info

Publication number: JP3805052B2
Application number: JP02066697A
Authority: JP
Inventors: 知佐早川; 秀雄池永
Original assignee: Asahi Kasei Fibers Corp
Current assignee: Asahi Kasei Fibers Corp
Priority date: 1997-02-03
Filing date: 1997-02-03
Publication date: 2006-08-02
Anticipated expiration: 2017-02-03
Also published as: JPH10219546A

Description

【０００１】
【発明の属する技術分野】
本発明は雨水や汗等による水滲みによる、変色を防止することができる混用布帛、詳しくは、ブラウス、スポーツシャツ、ズボン、ロングパンツ等の衣料用途の他、日用雑貨の用途においても好適に用いられる水による変色を防止する性能を備えた混用布帛に関する。
【０００２】
【従来の技術】
雨にぬれたり汗をかいたりしたときに、肩、脇や背中など衣服がぬれたところだけ変色、より詳しくは深色化してしまい不快感を覚えることがある。また水たまりの水はね等によってズボン、ロングパンツの裾が変色したときも外観上著しく不快感を与える。これは綿等の親水性繊維のみならずポリエステル繊維等の疎水性の合成繊維の編織物でもみられる欠点の１つである。
【０００３】
ぬれたときでも肌が透けにくい繊維材料として、芯部に白色顔料を多く含む芯鞘型複合繊維を用いた布帛が知られている（特開平５−９３３４３号公報等）。しかしながら、これらは白色顔料によって芯部の光反射を大きくして、水による繊維表面の屈折率低下で生じた白色光の割合の減少の寄与を小さくするというものであるため、ぬれても透けにくいという効果があるものの、水にぬれると変色してしまうという欠点はそのまま残る。従って水による変色を防止する性能を備えた布帛はこれまで知られていない。
【０００４】
【発明が解決しようとする課題】
本発明は水による変色を防止する性能を備えた単層の混用布帛を提供することを目的とする。
【０００５】
【課題を解決するための手段】
本発明の構成を説明する前に、まず、一般に繊維が水にぬれるとなぜ変色するかについて説明する。
人間が物を見るとき、目はその物体の表面で反射した表面反射光と、物体の内部に入り、内部境界面で反射される内部反射光を合わせた光をとらえる。表面反射光は入射光と同じあらゆる波長の光を含んだ白色光であり、内部反射光は染料によりある特定の波長の光の吸収を受けた着色光である。ここで、この白色光の割合が大きいほど白っぽく、白色光の割合が小さいほど色が深く見えることがわかっている。水は繊維より小さい屈折率（ｎ＝１．３３）を持つが、繊維が水にぬれると繊維表面が水に覆われて低屈折率化し、表面反射率が小さくなる。よって水にぬれると変色、すなわち深色化することになる。
【０００６】
本発明と同一の出願人は平成８年２月９日に特願平８−２３５９２号として出願した「変色を防止する布帛」において、表層が白色顔料の含有量が１重量％以上６重量％以下の合成繊維、及び／又は白色顔料の含有量が３重量％以下１５重量％以下の芯部と白色顔料の含有量が２重量％以下の鞘部を有する芯鞘型複合繊維で構成されており、裏層及び／又は中間層が保水性繊維で構成された二層以上の多層構造を有する布帛を提案し、かかる布帛は変色を防止することができることを見出した。しかし本願の如く単層構造の布帛では水を移行させる他層を有せず、したがってこの先行技術の何れか一層を用いた布帛では布帛の変色を充分に防止することができない。
そこで本発明者らは鋭意研究の結果、単層の中に上述の水に対して異なる性質を有する繊維から成る糸を混用することにより、優れた変色防止効果を与え得ることを見出し本発明に到達した。
【０００７】
本発明による水に対して異なる性質を有する複数種類の糸が単層内で混用されている変色防止性を有する混用布帛は、その混用布帛を構成する糸の中に、白色顔料の含有量が１重量％以上６重量％以下の合成繊維から成る糸、及び／又は白色顔料の含有量が３重量％以上１５重量％以下の芯部と白色顔料の含有量が２重量％以下の鞘部を有する芯鞘型複合繊維から成る糸であり、混用布帛中の少なくとも５０重量％は、白色顔料の含有量が１重量％以上であり、且つ水拡散性を有する合成繊維から成る糸であることを特徴とする。詳しくは、白色顔料の含有量が１重量％以上６重量％以下の合成繊維及び／又は白色顔料の含有量が３重量％以上１５重量％以下の芯部と白色顔料の含有量が２重量％以下の鞘部から成る芯鞘型複合繊維と、白色顔料の含有量が１重量％以上でかつ水拡散性を有する合成繊維の両者が一定量以上混用配置されているものである。好ましくは、前者の、白色顔料の含有量が１重量％以上６重量％以下の合成繊維及び／又は白色顔料の含有量が３重量％以上１５重量％以下の芯部と白色顔料の含有量が２重量％以下の鞘部から成る芯鞘型複合繊維を少なくとも２０重量％含むものである。
【０００８】
本発明の混用布帛は単層構造の布帛であれば編物、織物の何れであってもよい。水に対して異なる性質を有する繊維から成る２本（場合によっては３本以上）の糸を引揃えて布帛表面にそれぞれランダムに出るように編成したシングル編地や、給糸口１本置きにもしくは２本置きに上述の異なる繊維から成る２本の糸を供給することによって２本の糸をコース毎にもしくは２コース毎に交互に配置したシングル編地を用いることができる。編地の編組織はそれぞれの糸がランダムに布帛表面にでるシングル編地であれば、２コース天竺、鹿の子等の各種の編組織を用いることができる。またこれを応用して３本の糸がランダムに布帛表面にでる３コース天竺等も有用である。
織物の場合は水に対して異なる性質を有する繊維から成る２本の糸を経糸一本交互、緯糸一本交互、経緯一本交互に用いて本発明の単層構造の布帛を得ることができる。織物の織組織については特に限定することなく、平織、綾織、朱子織あるいはそれらの変形組織を用いることができる。また、これを応用して３本の糸を順に繰り返し配した繰り返し織も有用である。
【０００９】
本発明において用いられる白色顔料は、染色しても発色性の低下に問題がなく原糸製造に障害を及ぼさなければその種類は特に制限されないが、例えば酸化チタン、酸化亜鉛、酸化マグネシウム、炭酸カルシウム等の金属酸化物が望ましい。コストを考慮すると酸化チタンが最も適している。
【００１０】
芯鞘型複合繊維以外の繊維（以下普通繊維という。）の場合の白色顔料の含有量は１重量％以上６重量％以下にすることが肝要であり、２重量％以上５重量％以下が望ましい。なぜならば白色顔料の含有量が６重量％を超えると糸の強伸度が著しく低下し、原糸製造及び製編織工程通過を困難にする上、ガイド等を磨耗させ毛羽や筋等の欠点を起こしかねない。また１重量％未満では本発明が目的とする変色防止効果が得られない。
【００１１】
芯鞘型複合繊維の場合は芯部の白色顔料の含有量が３重量％以上１５重量％以下であることが肝要であり、５重量％以上１０重量％以下が望ましい。なぜなら芯部の白色顔料の含有量が１０重量％を超えると強度低下が徐々に始まり、１５重量％以上になると著しく強伸度低下をきたすからである。また３重量％未満では本発明の変色防止効果が得られない。そして芯部と鞘部はベースポリマーが同じであってもなくてもよい。例えばポリエステルの芯鞘型複合繊維の場合、鞘部のみカチオン可染ポリマーであってもよい。また、ポリアミドの芯鞘型複合繊維の場合、芯部がナイロン６６で鞘部がナイロン６であってもよく、任意の組合せを用いることができる。また、芯成分と鞘成分は同心円的に複合されていても偏心的に複合されていてもよい。また芯鞘重量比率は１／３〜３／１の範囲であることが好ましく、特に１／２〜２／１が望ましい。１／３未満であると変色防止効果が小さくなったり、３／１を超えると、紡糸時に芯成分を鞘成分で覆うことは困難となることがある。
【００１２】
本発明で用いる繊維は例えばポリアミド、ポリエステル、ポリプロピレン等の、溶融紡糸によって製造される繊維が製造工程上望ましく、それらの原糸、フィラメント加工糸どちらを用いてもよい。また普通繊維糸よりも芯鞘型複合繊維糸の方が変色防止効果が尚一層優れているので好ましい。変色防止効果以外にも芯鞘型複合繊維糸は白色顔料を均等に含有した普通繊維糸に比較して発色性、工程通過性も優れている。
本発明で用いられる糸の太さは、マルチフィラメントの場合で３０ｄ〜１５０ｄ、紡績糸の場合で１０ｓ〜４０ｓ（綿番手）が好ましく用いられる。ただしこの糸の太さに限定されるものではない。
【００１３】
本発明の混用布帛では前述のように白色顔料を相対的に多量に含有し、それによってぬれても変色しにくくかつ透けにくい糸と、ぬれた場合に早くその水分を他の区域に走行せしめながらも変色しにくい糸が必要となる。この後者の糸は水拡散性に優れた糸であることが必要である。
そこで本発明では水拡散性繊維糸として合成繊維糸を用いるに際して、捲縮による水の保持性及び合成繊維糸を構成する単繊維間の毛細管現象による水の拡散性を利用する。より具体的には断面形状がＬ、Ｃ、Ｗ、Ｚ、Ｍ、歯車形等の異形断面のフィラメント原糸及びそのフィラメント加工糸、中空・多孔質繊維（中空・空孔率３〜４０％好ましくは５％〜２０％）のフィラメント原糸及びそのフィラメント加工糸、又は単糸デニールが１．５ｄ以下のファインデニールの原糸及びそのフィラメント加工糸を用いるとよい。水の通り道を多くして水拡散性を高めるには断面形状Ｗ又は歯車形の異形断面かつ中空繊維、又は三角から八角の非丸形断面でかつ中空繊維にし、さらに単糸デニールをファインデニールにして繊維の表面積を高めるとよい。より具体的には、繊維を構成するフィラメントが図２のように異形度１．４以上２．２以下（好ましくは１．５以上）θ₁〜θ₃が２０°以上１６０°以下（好ましくは１２０°〜１５０°）のＷ形異形断面繊維、図３のように異形度１．１以上２．２以下（好ましくは１．２以上）でほぼ円形の中空部をフィラメントの長さ方向に３つ持ち、トータルの中空率が５％以上１０％以下の三角断面糸がよい。特にＷ形断面糸はこのＷ形断面糸が重なり合った時にできる細い毛細管により、毛管吸引力が大きくなること、又この断面形状であると一度保持した水を他に移すことなく（ぬれ戻ることなく）水を抱え持つ性質もあるため、多量の汗を生ずるスポーツ衣料に用いると、冷え感やべとつきを全く感じないドライ性を発揮して、変色防止性と着用快適性を兼ね備えたものにすることができる。この水拡散性繊維は混用糸重量の５０重量％以上８０重量％以下より好ましくは６０重量％以上７０重量％以下であるとよい。この水拡散性繊維は、異形断面繊維や中空繊維、ファインデニール繊維等であるため、工程管理を通常より慎重にする必要もあり繊維材料として８０重量％以上含有すると染め筋等の欠点が見えやすくなることがある。５０重量％以下では水拡散性が充分達成できない。
【００１４】
本発明における水拡散性繊維の異形度は１．２以上２．２以下であると好ましい。又１．４以上２．２以下であるとさらに好ましい。１．２以上であると丸断面よりも格段に水拡散性に優れたものとなり、２．２を越えると紡糸性等の製造安定性に劣るので好ましくない。本発明でいう異形度は、異形糸の断面積と周長（周囲の長さ）を算出し、次に同じ断面積を持つ真円の半径を求め、そこからその真円の周長を算出し、次式により求める。
異形度＝異形糸の周長／異形糸と同じ断面積の真円の周長
【００１５】
前記のように合成繊維の原糸にフィラメント加工を施して捲縮を与えると、捲縮による水の物理的保持によって水の保持性を高めた合成繊維糸を得ることができる。ただしこの場合の捲縮は低捲縮、すなわち捲縮伸長率で１０％以下、好ましくは５〜７％であるとよい。これは高捲縮であると物理的に水を保持するスペースは増すが、逆に水の拡散性が著しく低下することになり、布帛の変色防止にはマイナスに作用するからである。このように合成繊維糸の形状や加工条件を適切に選定すれば、水拡散性において総合的に天然繊維や、人造セルロース繊維を上廻る繊維糸を得ることができる。
本発明の混用布帛で混用されることになる水拡散性繊維としては、後述する測定法によって求められる吸水性値及び水拡散性値それぞれ２cm以上及び１０cm以上の値を示す繊維を用いることが好ましい。合成繊維の異形断面繊維は、異形度を大きくすることによって、水拡散性値１０cm以上を示す繊維が得られる。例えば、単糸デニールが１．７ｄ好ましくは１．５以下の繊維の場合、異形度が１．４以上を示すＷ形断面繊維で水拡散性値が１５cm以上を示すポリエステル繊維、ナイロン繊維を得ることができる。前記した空孔率を有する多孔繊維、中空繊維は、前記レベルの水拡散性値を有する繊維が得られる。そして、異形断面繊維や多孔繊維等は、その形態効果に因って概ね２．１cm以上の吸水性を示す。
異形度が１．１〜１．４の異形断面繊維は、単糸繊度が１．７ｄ以下で水拡散性値が１２cm以上を示す。捲縮伸長率が５〜７％の丸形断面繊維によっても水拡散性値１０cm以上、吸水性値２cm以上の繊維が得られる。
【００１６】
前述の水拡散性を有する合成繊維糸を白色顔料を多量に含有する糸と混用して用いれば、布帛に接触した水分は前記単層内の水拡散性を有する合成繊維糸に吸収され、更に吸収された水分は布帛内を移行して拡散することになり、布帛の変色を防止するのに役立つ。
【００１７】
本発明における混用布帛において水拡散性を有する合成繊維糸にも白色顔料を特定量（１重量％以上）含有させると良い。これは水拡散性繊維糸自体の変色を白色顔料によって抑えることになり混用布帛全体の変色防止効果を尚一層高めるのに役立つ。
【００１８】
本発明の混用布帛の吸水性を更に高めるために混用布帛の染色仕上工程の最終段階で吸収剤を付与してもよい。このように吸収剤を付与すると合成繊維の水との親和性が向上し、水の拡散性が向上して変色の程度が小さくなる。例えば高松油脂（株）製のＳＲシリーズ、センカ（株）製のファインセットＦ１０１等の親水性共重合物を主成分とする吸水剤又は親水化剤を３〜５％ｏｗｆ付与すると良い。その際洗濯や長期着用に対する吸水剤の耐久性を向上させる仕上処理を行うと変色防止効果を長期間維持できるので好ましい。
【００１９】
次に本発明による混用布帛を構成する糸及び混用布帛自体の各種物性値の定義及び測定又は評価方法を以下にまとめて説明する。
（１）捲縮伸長率
ＪＩＳ−Ｌ−１０９０（１９９２）合成繊維嵩高加工糸試験方法、５．７伸縮法Ｂ法により測定する。
先ず下記方法により前処理した試料片をつくる。
試料を、試料に損傷を与えない様な棒に掛けて輪にしたもの５個作り、それぞれに２mgf ×試料表示デニール数の荷重をかける。次に、この５個の試料をひとまとめにして約５０cmの間隔をおき上下を綿糸でしっかり結んだ後、直ちに除重する。続いて０．３mgf ×１０×試料表示デニール数の荷重を掛けながら９０℃で１５分間乾熱処理を行い、除重後一昼夜放置する。
このような前処理をした１０本１束の試料片を、前記ＪＩＳ−Ｌ−１０９０，５．７伸縮性Ｂ法に基づき、２mgf ×１０×試料表示デニール数の初荷重をかけた状態で、試験長が約２０cmになるよう試料片上部をクランプで固定し、３０秒後の試料長（ａ）を正確に測定する。次に、０．１gf×１０×試料表示デニール数の荷重をかけて３０秒後の試料長（ｂ）を正確に測定する。そして次式によって捲縮伸長率（％）を算出する。
捲縮伸長率（％）＝〔（ｂ−ａ）／ａ〕×１００
【００２０】
（２）糸の吸水性
混用布帛の吸水性は測定はできるがこの布帛は複数の繊維で構成されるので、糸そのものの吸水性が測定できない。そこで混用布帛を構成する繊維をかせ巻きにし、目的とする混用布帛の製造に際して用いられる精練・染色・乾燥工程と同一条件で精練・染色・乾燥して試料糸とする。
ただし、使用繊維がフィラメント糸の場合は実施例、比較例で用いられるフィラメント糸の単糸デニールと同一の単糸デニールの単糸を束ねてトータルデニールが７５ｄ±５ｄになるように試験用の糸を用意し、この糸に３００Ｔ／ｍの撚をかけ、１００℃×１５分間スチームでセットし、乾燥の後、２０℃、湿度６５％RHで一昼夜放置して試料糸を調整する。
使用繊維が短繊維である紡績糸の場合は、下記式で示す撚係数が１２０になるようなｍ当り撚数の撚を有する綿糸１０ｓに相当する太さと撚を有する糸を合糸によって調整し試料糸とする。
Ｔ＝α×√Ｎ
Ｔ：ｍ当り撚数、Ｎ：綿番手、α：撚係数
この糸から測定サンプルとして５０cm切り取り、上端を固定した状態で０．１ｇ／ｄの荷重を糸の下端にかけた後、下端を水（常温）につけ、１０分後に水の吸い上げ鉛直距離を測定する。評価は１０本の平均値をもって行う。この吸い上げ距離が２cm以上である場合に吸水性良好であると評価する。
【００２１】
（３）糸の水拡散性
吸水性の測定に用いた試料糸と同一の糸を用いて水拡散性を測定する。前記試料糸１ｍを切り取り、糸の一端を固定した状態で、もう一方の端に程近い部分を滑車にひっかけた後、その端に０．１ｇ／ｄの荷重をかけて水平に糸を張る。緊張下の糸の中央付近に０．０１ccの水を与えて１０分後の水の水平方向移動距離を測定する。測定は２０℃、湿度６５％RH下で行い、１０本の測定値の平均で水拡散性を評価した。移動距離が１０cm以上の糸を水拡散性良好と評価する。
【００２２】
（４）布帛での変色防止性の評価
下記に示す測色計による数値評価と官能評価を併せて行った。
（ａ）測色計による数値で示す色差（ΔＥ＊）
サカタインクス（株）製の測色計マクベスカラーアイ３０００を用いて測定する。
▲１▼１０cm×１０cm程度の乾燥した試料サンプルを２つ折りにして測色計の直径２．５cmの測色部に当て光源Ｃを用いて測定し、知覚色度指数ａ^*，ｂ^*及び明度Ｌ^*を得る。得られた値をそれぞれ知覚色度指数及び明度のスタンダード値とする。
▲２▼次に水１ミリリットルを試料サンプルに与え３０秒後にぬれ拡った部分を測定し、同様に知覚色度指数ａ^*，ｂ^*及び明度Ｌ^*を得る。得られた値をそれぞれ知覚色度指数及び明度のトライアル値とする。
▲３▼知覚色度指数ａ^*，ｂ^*及び明度Ｌ^*のスタンダード値とトライアル値との差を次式に代入して色差ΔＥ^*を得る。サンプル数は２である。
ΔＥ^*＝｛（ΔＬ^*）²＋（Δａ^*）²＋（Δｂ^*）²｝^1/2
（ｂ）官能評価
５人の検査員に目視による変色程度の評価を依頼し、得られた評価の平均値を下記官能評価基準により分類した。
評価サンプルとして２０cm×２０cmの布帛の試料片を用意し、そのほぼ中央部分に１ミリリットルの水を滴下し、３０秒後に水の滴下によって変色した部分と周辺区域を比較する。
変色の小さいものから順に、
◎↑ 乾湿間の色の差が全くない
◎ 〃〃殆どない
○ 〃〃あまりない
△ 〃〃ややある
× 〃〃大いにある
前記乾湿時の色差が大きい程官能検査で不快を感じる。好ましい乾湿時の色差は５以下である。
【００２３】
（５）工程通過性
実施例、比較例中の工程通過性が良いものというのは、編織工程で、編織機に対してガイド等へ摩耗や傷を与えたりしないのもをいう。
【００２４】
〔実施例１〕
７５ｄ／３６ｆで酸化チタンを８重量％含有した芯部と、酸化チタンを０．０５重量％含有した鞘部からなり芯鞘重量比１／１のポリエステル芯鞘型複合繊維糸Ａと、７５ｄ／３０ｆで酸化チタンを１重量％含有したθ_１＝θ_２＝θ_３＝１３５°であるポリエステルのＷ型異形断面繊維糸（異形度１．５５）Ｂを作った。２８ＧＧシングル編機で各々の糸が千鳥格子になるように糸を配して、混率１：１で２コースごとに分けて編成される目付１３０ｇ／ｍ^２の２コース天竺編地を作成し、染色した。この編地の表面観察を行ったところ、糸Ａが４８％、糸Ｂが５２％を占めていた。この布帛はぬれたときの変色が大変小さいものとなった。
【００２５】
〔実施例２〕
７５ｄ／３６ｆで酸化チタンを８重量％含有した芯部と、酸化チタンを０．０５重量％含有した鞘部からなり芯鞘重量比１／１のポリエステル芯鞘型複合繊維糸Ａと、７５ｄ／３０ｆで酸化チタンを１重量％含有した前述のポリエステルのＷ型異形断面繊維糸（異形度１．５５）Ｂを作った。２８ＧＧシングル編機で各々の糸が千鳥格子になるように糸を配して、混率１：１で２コースごとに分けて編成される目付１３０ｇ／ｍ^２の２コース天竺編地を作成し、染色した後、吸水加工を行った。この編地は表面観察を行ったところ、糸Ａが４８％、糸Ｂが５２％を占めていた。この布帛は変色が大変小さく、ぬれていることを感じさせないものとなった。
【００２６】
〔実施例３〕
７５ｄ／３６ｆで酸化チタンを３重量％含有し、中空率８％でほぼ円形の中空部を繊維の長さ方向に３つ有したポリエステル三角断面繊維糸（異形度１．２）Ｃと、７５ｄ／３６ｆで酸化チタンを２重量％含有したポリエステル繊維糸Ｄを作った。同様に目付１３０ｇ／ｍ^２の２コース天竺を作成し、染色した。この編地の表面観察を行ったところ、糸Ｃが５３％、糸Ｄが４７％を占めていた。この布帛はぬれたときの変色が小さいものとなった。
【００２７】
〔比較例１〕
７５ｄ／３６ｆで酸化チタンを２重量％含有した芯部と、酸化チタンを０．０５重量％含有した鞘部からなり芯鞘重量比率１／１のポリエステルの芯鞘型複合繊維糸Ｅと、７５ｄ／２４ｆで酸化チタンを０．１重量％含有したポリエステル繊維糸Ｆを作った。同様に目付１２２ｇ／ｍ^２の２コース天竺を作成し、染色した。この編地の表面観察を行ったところ、糸Ｅが５２％、糸Ｆが４８％を占めていた。この布帛はぬれたとき変色するものとなった。
【００２８】
〔比較例２〕
７５ｄ／３６ｆで酸化チタンを３重量％含有したポリエステル繊維糸Ｇと、７５ｄ／３６ｆで酸化チタンを０．１重量％含有したポリエステル繊維糸Ｈを作った。同様に目付１２５ｇ／ｍ^２の２コース天竺を作成し、染色した。この編地の表面観察を行ったところ、糸Ｇが５０％、糸Ｈが５０％を占めていた。この布帛はぬれたときに変色するものとなった。
【００２９】
【表１】

【００３１】
〔比較例３〕
経糸を５０ｄ／３６ｆで酸化チタンを０．１重量％含有するポリエステル繊維糸、緯糸を７５ｄ／３６ｆで酸化チタンを０．１重量％含有したポリエステル繊維糸と７５ｄ／２４ｆで酸化チタンを３重量％含有するポリエステル繊維糸を一本交互に配し、常法の織機を用いて経糸密度１４０本、緯糸密度８５本、目付９３ｇ／ｍ²の平織物を作成し、染色、吸水加工を行った。この布帛はぬれたとき変色するものとなった。
【００３２】
【発明の効果】
本発明によれば、雨又は汗などによる布帛の変色を防止でき、その結果水による変色に基づく不快感のない布帛を提供できる。なお本発明の混用布帛は原料糸の製造時および布帛の製造時における糸切れ等のトラブルが殆ど無く、工程通過性が良好であった。
【図面の簡単な説明】
【図１】混用布帛の一例を示す２コース天竺編地の編方図。
【図２】本発明の変色防止混用布帛に用いられるＷ形異形断面繊維の単糸断面の１例を示す。
【図３】本発明の変色防止混用布帛に用いられる中空部を有する繊維の三角断面単糸断面の１例を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention is a mixed fabric that can prevent discoloration due to water bleeding due to rainwater, sweat, etc., and more particularly suitable for use in daily goods as well as clothing such as blouses, sports shirts, trousers, and long pants. The present invention relates to a mixed fabric having the ability to prevent discoloration due to water used.
[0002]
[Prior art]
When it gets wet or sweats, it can discolor only where the clothes are wet, such as the shoulders, sides, and back, and more specifically, it may become discolored, causing discomfort. Also, when the trousers and long pants are discolored due to splashes of puddle, etc., the appearance is significantly uncomfortable. This is one of the disadvantages observed in knitted fabrics of hydrophobic synthetic fibers such as polyester fibers as well as hydrophilic fibers such as cotton.
[0003]
A fabric using a core-sheath type composite fiber containing a large amount of white pigment in the core is known as a fiber material that does not allow skin to penetrate even when wet (Japanese Patent Laid-Open No. 5-93343). However, these increase the light reflection of the core by the white pigment and reduce the contribution of the decrease in the proportion of white light caused by the decrease in the refractive index of the fiber surface due to water. The effect of discoloring when wet is left intact. Therefore, a fabric having the ability to prevent discoloration due to water has not been known so far.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a single-layer mixed fabric having the performance of preventing discoloration due to water.
[0005]
[Means for Solving the Problems]
Before explaining the structure of the present invention, first, why the color changes when the fiber is wet will be explained.
When a human sees an object, the eye captures the combined light of the surface reflected light reflected by the surface of the object and the internally reflected light that enters the object and is reflected by the internal interface. The surface reflected light is white light containing light of all the same wavelengths as the incident light, and the internally reflected light is colored light that has been absorbed by light of a specific wavelength by the dye. Here, it is known that the larger the ratio of white light, the more whitish, and the smaller the ratio of white light, the deeper the color. Water has a smaller refractive index (n = 1.33) than the fiber, but when the fiber is wetted with water, the fiber surface is covered with water to lower the refractive index, and the surface reflectance decreases. Therefore, when it gets wet, it changes color, that is, deep color.
[0006]
The same applicant as that of the present invention filed a Japanese Patent Application No. 8-23592 filed on Feb. 9, 1996 as “Fabrics to prevent discoloration”, and the surface layer contained 1 wt% or more and 6 wt% of white pigment. It is composed of the following synthetic fiber and / or a core-sheath type composite fiber having a core part with a white pigment content of 3% by weight or less and 15% by weight or less and a sheath part with a white pigment content of 2% by weight or less. The present inventors have proposed a fabric having a multilayer structure of two or more layers in which the back layer and / or the intermediate layer is composed of water-retaining fibers, and found that such fabric can prevent discoloration. However, a fabric having a single layer structure as in the present application does not have other layers for transferring water, and therefore, a fabric using any one layer of this prior art cannot sufficiently prevent discoloration of the fabric.
Therefore, as a result of earnest research, the present inventors have found that an excellent discoloration prevention effect can be provided by mixing yarns made of fibers having different properties with respect to water as described above into a single layer. Reached.
[0007]
The mixed fabric having anti-discoloration property in which a plurality of types of yarn having different properties with respect to water according to the present invention are mixed in a single layer has a white pigment content in the yarn constituting the mixed fabric. A yarn composed of 1% by weight to 6% by weight synthetic fiber and / or a core part having a white pigment content of 3% by weight to 15% by weight and a sheath part having a white pigment content of 2% by weight or less. A yarn composed of a core-sheath type composite fiber having at least 50% by weight in the mixed fabric, wherein the white pigment content is 1% by weight or more, and the yarn is composed of a synthetic fiber having water diffusibility. Features. Specifically, the synthetic fiber having a white pigment content of 1% by weight to 6% by weight and / or the core having a white pigment content of 3% by weight to 15% by weight and the white pigment content of 2% by weight. Both a core-sheath type composite fiber having the following sheath part and a synthetic fiber having a white pigment content of 1% by weight or more and water diffusibility are mixedly arranged. Preferably, the former has a white pigment content of 1% by weight to 6% by weight and / or a synthetic fiber and / or a white pigment content of 3% by weight to 15% by weight and a white pigment content. It contains at least 20% by weight of a core-sheath type composite fiber having a sheath part of 2% by weight or less.
[0008]
The mixed fabric of the present invention may be a knitted fabric or a woven fabric as long as the fabric has a single layer structure. A single knitted fabric knitted so that two yarns (three or more in some cases) made of fibers having different properties with respect to water are arranged at random on the fabric surface, or every other yarn feeder, or A single knitted fabric in which two yarns are alternately arranged for each course or every two courses by supplying two yarns made of the above-mentioned different fibers every two can be used. As long as the knitting structure of the knitted fabric is a single knitted fabric in which each yarn appears at random on the surface of the fabric, various knitting structures such as a two-course tengu and a kanoko can be used. In addition, a three-course tengu or the like in which three yarns appear on the fabric surface at random by applying this is also useful.
In the case of a woven fabric, a single-layered fabric of the present invention can be obtained by using two yarns made of fibers having different properties with respect to water alternately in one warp, alternately in one weft, and alternately in one weft. . The woven structure of the woven fabric is not particularly limited, and plain weave, twill weave, satin weave or a deformed structure thereof can be used. A repeated weaving in which three yarns are repeatedly arranged in order by applying this is also useful.
[0009]
The type of white pigment used in the present invention is not particularly limited as long as it does not cause a problem of deterioration in color developability even if dyeing and does not impair the production of raw yarn. For example, titanium oxide, zinc oxide, magnesium oxide, calcium carbonate Metal oxides such as are desirable. In view of cost, titanium oxide is most suitable.
[0010]
In the case of fibers other than the core-sheath type composite fibers (hereinafter referred to as ordinary fibers), it is important that the content of the white pigment is 1% by weight to 6% by weight, and preferably 2% by weight to 5% by weight. . This is because when the white pigment content exceeds 6% by weight, the strength and elongation of the yarn is remarkably lowered, making it difficult to manufacture the yarn and passing through the weaving and weaving process. It can happen. On the other hand, if it is less than 1% by weight, the intended discoloration prevention effect of the present invention cannot be obtained.
[0011]
In the case of the core-sheath type composite fiber, it is important that the content of the white pigment in the core is 3% by weight to 15% by weight, and preferably 5% by weight to 10% by weight. This is because when the content of the white pigment in the core exceeds 10% by weight, the strength starts to decrease gradually, and when it exceeds 15% by weight, the strength and elongation decrease significantly. If it is less than 3% by weight, the effect of preventing discoloration of the present invention cannot be obtained. And the core part and the sheath part may or may not have the same base polymer. For example, in the case of polyester core-sheath type composite fiber, only the sheath part may be a cationic dyeable polymer. Further, in the case of polyamide core-sheath type composite fiber, the core part may be nylon 66 and the sheath part may be nylon 6, and any combination can be used. Further, the core component and the sheath component may be combined concentrically or may be combined eccentrically. The core-sheath weight ratio is preferably in the range of 1/3 to 3/1, and more preferably 1/2 to 2/1. If it is less than 1/3, the effect of preventing discoloration may be reduced, and if it exceeds 3/1, it may be difficult to cover the core component with a sheath component during spinning.
[0012]
The fiber used in the present invention is preferably a fiber produced by melt spinning, such as polyamide, polyester, or polypropylene, in the production process, and either the original yarn or the filament processed yarn may be used. Further, the core-sheath type composite fiber yarn is preferable to the ordinary fiber yarn because the discoloration preventing effect is still more excellent. In addition to the effect of preventing discoloration, the core-sheath type composite fiber yarn is excellent in color development and process passability as compared with a normal fiber yarn containing a white pigment uniformly.
The thickness of the yarn used in the present invention is preferably 30d to 150d in the case of multifilament and 10s to 40s (cotton count) in the case of spun yarn. However, it is not limited to the thickness of this thread.
[0013]
As described above, the mixed fabric of the present invention contains a relatively large amount of white pigment, which makes it difficult to discolor even when wet and to prevent see-through, and to quickly move the moisture to other areas when wet. It is necessary to use a thread that is difficult to discolor. This latter yarn needs to be a yarn excellent in water diffusibility.
Therefore, in the present invention, when the synthetic fiber yarn is used as the water diffusible fiber yarn, the water retainability by crimping and the water diffusibility by the capillary phenomenon between the single fibers constituting the synthetic fiber yarn are utilized. More specifically, the filament raw yarn having a cross-sectional shape such as L, C, W, Z, M, and a gear shape, and the filament processed yarn, hollow / porous fiber (hollow / porosity 3 to 40%, preferably 5% to 20%) filament raw yarn and filament processed yarn thereof, or fine denier raw yarn having a single yarn denier of 1.5 d or less and filament processed yarn thereof may be used. In order to increase the water diffusivity by increasing the number of water passages, the cross-sectional shape W or gear-shaped irregular cross-section and hollow fiber, or triangular to octagonal non-circular cross-section and hollow fiber, and the single yarn denier is fine denier To increase the surface area of the fibers. More specifically, the filament constituting the fiber has an irregularity of 1.4 or more and 2.2 or less (preferably 1.5 or more) as shown in FIG. 2, and θ _{1 to} θ ₃ is 20 ° or more and 160 ° or less (preferably 120 ° -150 °) W-shaped irregular cross-section fiber, as shown in FIG. 3, an almost circular hollow portion having an irregularity of 1.1 to 2.2 (preferably 1.2 or more) is arranged in the length direction of the filament. A triangular cross-section yarn having a total hollowness of 5% to 10% is preferable. In particular, the W-shaped cross-section yarn has a thin capillary tube formed when the W-shaped cross-sectional yarns are overlapped, so that the capillary suction force is increased, and once the cross-sectional shape is reached, the water once retained is not transferred to another (without wetting back). ) Since it has the property of holding water, when used in sports clothing that generates a large amount of sweat, it should exhibit dryness that does not feel cold or stickiness at all, and should have both discoloration prevention and wearing comfort. Can do. The water-diffusible fiber may be 50% by weight to 80% by weight and more preferably 60% by weight to 70% by weight of the mixed yarn weight. Since this water-diffusible fiber is an irregular cross-section fiber, hollow fiber, fine denier fiber, etc., it is necessary to make process control more cautious than usual, and if it is contained at 80% by weight or more as a fiber material, defects such as dyed streak are easily visible. May be. If it is 50% by weight or less, water diffusibility cannot be sufficiently achieved.
[0014]
The degree of irregularity of the water-diffusible fiber in the present invention is preferably 1.2 or more and 2.2 or less. Further, it is more preferably 1.4 or more and 2.2 or less. If it is 1.2 or more, water diffusibility is remarkably superior to that of a round cross section, and if it exceeds 2.2, production stability such as spinnability is inferior. In the present invention, the degree of deformity is calculated by calculating the cross-sectional area and circumference (peripheral length) of the deformed yarn, then calculating the radius of a perfect circle having the same cross-sectional area, and calculating the circumference of the true circle therefrom. And obtained by the following equation.
Degree of deformity = circumference of deformed yarn / circumference of a perfect circle having the same cross-sectional area as the deformed yarn
As described above, when a synthetic fiber yarn is subjected to filament processing to be crimped, a synthetic fiber yarn having improved water retention by physical retention of water by crimping can be obtained. However, the crimp in this case is low crimp, that is, the crimp elongation rate is 10% or less, preferably 5 to 7%. This is because, if the crimp is highly crimped, the space for physically holding water is increased, but conversely, the diffusibility of water is remarkably lowered, and this has a negative effect on preventing discoloration of the fabric. As described above, when the shape and processing conditions of the synthetic fiber yarn are appropriately selected, it is possible to obtain a fiber yarn that generally exceeds natural fibers and artificial cellulose fibers in terms of water diffusibility.
As the water diffusible fiber to be mixed in the mixed fabric of the present invention, it is preferable to use a fiber having a water absorption value and a water diffusibility value obtained by a measurement method described later, which are 2 cm or more and 10 cm or more, respectively. . As for the irregular cross-section fiber of the synthetic fiber, a fiber exhibiting a water diffusibility value of 10 cm or more can be obtained by increasing the degree of irregularity. For example, in the case of a fiber having a single yarn denier of 1.7 d, preferably 1.5 or less, a polyester fiber or a nylon fiber having a W-shaped cross-section fiber having an irregularity of 1.4 or more and a water diffusibility value of 15 cm or more is obtained. be able to. As for the porous fiber and the hollow fiber having the porosity described above, a fiber having the above-mentioned level of water diffusibility value can be obtained. And irregular cross-section fiber, porous fiber, etc. show a water absorption of about 2.1 cm or more due to their morphological effects.
An irregular cross-section fiber having an irregularity of 1.1 to 1.4 has a single yarn fineness of 1.7 d or less and a water diffusibility value of 12 cm or more. A fiber having a water diffusibility value of 10 cm or more and a water absorption value of 2 cm or more can be obtained even with a round cross-section fiber having a crimp elongation of 5 to 7%.
[0016]
If the above-mentioned synthetic fiber yarn having water diffusibility is used in combination with a yarn containing a large amount of white pigment, moisture in contact with the fabric is absorbed by the synthetic fiber yarn having water diffusibility in the single layer, and The absorbed moisture will migrate and diffuse within the fabric, helping to prevent discoloration of the fabric.
[0017]
In the mixed fabric according to the present invention, a specific amount (1% by weight or more) of a white pigment may be contained in the synthetic fiber yarn having water diffusibility. This suppresses the discoloration of the water diffusible fiber yarn itself by the white pigment and helps to further enhance the discoloration prevention effect of the entire mixed fabric.
[0018]
In order to further increase the water absorption of the mixed fabric of the present invention, an absorbent may be added at the final stage of the dyeing finish process of the mixed fabric. When the absorbent is applied in this manner, the affinity of the synthetic fiber with water is improved, the diffusibility of water is improved, and the degree of discoloration is reduced. For example, a water-absorbing agent or a hydrophilizing agent mainly composed of a hydrophilic copolymer such as SR series manufactured by Takamatsu Yushi Co., Ltd. or Fine Set F101 manufactured by Senka Co., Ltd. may be added. At that time, it is preferable to perform a finishing treatment that improves the durability of the water-absorbing agent for washing and long-term wearing because the discoloration preventing effect can be maintained for a long time.
[0019]
Next, the definition and measurement or evaluation method of various physical property values of the yarn constituting the mixed fabric according to the present invention and the mixed fabric itself will be described below.
(1) Crimp elongation rate Measured by JIS-L-1090 (1992) synthetic fiber bulky processed yarn test method, 5.7 stretch method B method.
First, a pretreated sample piece is prepared by the following method.
Make five samples by putting them on a rod that does not damage the sample, and apply a load of 2 mgf x sample display denier. Next, the five samples are put together and spaced about 50 cm apart, and the upper and lower sides are tightly tied with cotton yarn, and then immediately deweighted. Subsequently, a dry heat treatment is performed at 90 ° C. for 15 minutes while applying a load of 0.3 mgf × 10 × sample display denier, and the sample is left for a whole day and night after dewetting.
In a state in which a sample piece of 10 bundles having been subjected to such pretreatment was subjected to an initial load of 2 mgf × 10 × sample display denier number based on the JIS-L-1090, 5.7 stretch B method, The upper part of the sample piece is fixed with a clamp so that the test length is about 20 cm, and the sample length (a) after 30 seconds is accurately measured. Next, the sample length (b) after 30 seconds is accurately measured with a load of 0.1 gf × 10 × sample display denier. Then, the crimp expansion rate (%) is calculated by the following equation.
Crimp elongation (%) = [(ba) / a] × 100
[0020]
(2) Although the water absorbency of the water-absorbent mixed fabric of yarn can be measured, since this fabric is composed of a plurality of fibers, the water absorbency of the yarn itself cannot be measured. Therefore, the fibers constituting the mixed fabric are squeezed and scoured, dyed and dried under the same conditions as the scouring, dyeing and drying steps used in the production of the desired mixed fabric to obtain a sample yarn.
However, when the used fiber is a filament yarn, a yarn for testing so that the total denier is 75d ± 5d by bundling single yarns of the same single yarn denier as the filament yarn used in the examples and comparative examples. A 300 T / m twist is applied to the yarn, and it is set with steam at 100 ° C. for 15 minutes. After drying, it is left to stand at 20 ° C. and a humidity of 65% RH for 24 hours to adjust the sample yarn.
In the case of a spun yarn in which the used fiber is a short fiber, a yarn having a thickness and a twist corresponding to the cotton yarn 10s having a twist of a twist number per m such that the twist coefficient represented by the following formula is 120 is adjusted by combining the yarns. Use sample yarn.
T = α × √N
T: Number of twists per m, N: Cotton count, α: Twist factor A 50 cm sample was cut from this yarn as a measurement sample, and a load of 0.1 g / d was applied to the lower end of the yarn with the upper end fixed. Measure the vertical distance of water uptake after 10 minutes. The evaluation is performed with an average value of 10 pieces. When this suction distance is 2 cm or more, it is evaluated that water absorption is good.
[0021]
(3) Water diffusibility of the yarn The water diffusivity is measured using the same yarn as the sample yarn used for the measurement of water absorption. The sample yarn 1m is cut out, and one end of the yarn is fixed, and a portion close to the other end is caught on the pulley, and then a load of 0.1 g / d is applied to the end to stretch the yarn horizontally. Apply 0.01 cc of water near the center of the thread under tension and measure the horizontal movement distance of the water 10 minutes later. The measurement was performed at 20 ° C. and a humidity of 65% RH, and the water diffusibility was evaluated by averaging 10 measured values. A yarn having a moving distance of 10 cm or more is evaluated as having good water diffusibility.
[0022]
(4) Evaluation of anti-discoloration property in fabrics Numerical evaluation and sensory evaluation by a colorimeter shown below were performed together.
(A) Color difference (ΔE *) indicated by a numerical value by a colorimeter
Measurement is carried out using a colorimeter Macbeth Color Eye 3000 manufactured by Sakata Inx Corporation.
(1) A dried sample sample of about 10 cm × 10 cm is folded in half and applied to the colorimetric part of the colorimeter with a diameter of 2.5 cm using the light source C to measure the perceptual chromaticity index a ^* , b ^* and brightness. Get L ^* . The obtained values are used as standard values of perceptual chromaticity index and lightness, respectively.
{Circle around (2)} Next, 1 ml of water is applied to the sample sample, and the wetted and expanded portion is measured after 30 seconds. Similarly, the perceptual chromaticity indices a ^* and b ^* and the lightness L ^* are obtained. The obtained values are used as perceptual chromaticity index and lightness trial values, respectively.
(3) The difference between the standard value and the trial value of the perceptual chromaticity index a ^* , b ^* and lightness L ^* is substituted into the following equation to obtain the color difference ΔE ^* . The number of samples is 2.
ΔE ^* = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2
(B) Sensory evaluation Five inspectors were asked to evaluate the degree of discoloration by visual inspection, and the average value of the obtained evaluations was classified according to the following sensory evaluation criteria.
A sample piece of a fabric of 20 cm × 20 cm is prepared as an evaluation sample, and 1 milliliter of water is dropped on the substantially central portion thereof, and a portion discolored by dropping of water after 30 seconds is compared with the surrounding area.
In order from the smallest discoloration,
◎ ↑ There is no color difference between wet and dry ◎ 〃ない Almost no 〃〃ない Not much △ 〃〃 Somewhat × 〃〃 The greater the color difference at the time of wet and dry, the more uncomfortable the sensory test feels. A preferable color difference at the time of wet and dry is 5 or less.
[0023]
(5) Process passability Good process passability in the examples and comparative examples means that in the knitting process, the guide or the like is not worn or scratched on the weaving machine.
[0024]
[Example 1]
A polyester core-sheath type composite fiber yarn A having a core-sheath weight ratio of 1/1 having a core part containing 8% by weight of titanium oxide at 75d / 36f and a sheath part containing 0.05% by weight of titanium oxide; Polyester W-shaped irregular cross-section fiber yarn (degree of irregularity 1.55 ) B containing θ ₁ = θ ₂ = θ ₃ = 135 ° containing 1% by weight of titanium oxide at 30f was produced. Using a 28GG single knitting machine, arrange the yarns so that each yarn is in a staggered pattern, and create a two-course tengu knitted fabric with a basis weight of 130 g / m ² that is knitted in two courses with a mixture ratio of 1: 1. Stained. When the surface of this knitted fabric was observed, the yarn A accounted for 48% and the yarn B accounted for 52%. This fabric had very little discoloration when wet.
[0025]
[Example 2]
A polyester core-sheath type composite fiber yarn A having a core-sheath weight ratio of 1/1 having a core part containing 8% by weight of titanium oxide at 75d / 36f and a sheath part containing 0.05% by weight of titanium oxide; At 30 f, the above-mentioned polyester W-shaped cross-section fiber yarn (profile degree 1.55 ) B containing 1% by weight of titanium oxide at 30 f was produced. Using a 28GG single knitting machine, arrange the yarns so that each yarn is in a staggered pattern, and create a two-course tengu knitted fabric with a basis weight of 130 g / m ² that is knitted in two courses with a mixture ratio of 1: 1. After dyeing, water absorption processing was performed. When the surface of this knitted fabric was observed, 48% of yarn A and 52% of yarn B accounted for. This fabric had very little discoloration and did not feel wet.
[0026]
Example 3
75d / 36f, containing 3% by weight of titanium oxide, having a hollow ratio of 8%, and having three substantially circular hollow parts in the fiber length direction, a polyester triangular cross-section fiber yarn (profile degree 1.2 ) C , 75d Polyester fiber yarn D containing 2% by weight of titanium oxide at / 36f was made. Similarly, a two-course tengu with a basis weight of 130 g / m ² was prepared and dyed. When the surface of this knitted fabric was observed, the yarn C accounted for 53% and the yarn D accounted for 47%. This fabric was small in discoloration when wet.
[0027]
[Comparative Example 1]
A core-sheath type composite fiber yarn E of polyester having a core-sheath weight ratio of 1/1 comprising a core part containing 2% by weight of titanium oxide at 75d / 36f and a sheath part containing 0.05% by weight of titanium oxide; Polyester fiber yarn F containing 0.1% by weight of titanium oxide at / 24f was produced. Similarly, a two-course tengu with a basis weight of 122 g / m ² was prepared and dyed. When the surface of this knitted fabric was observed, the yarn E accounted for 52% and the yarn F accounted for 48%. This fabric became discolored when wet.
[0028]
[Comparative Example 2]
A polyester fiber yarn G containing 3% by weight of titanium oxide at 75d / 36f and a polyester fiber yarn H containing 0.1% by weight of titanium oxide at 75d / 36f were prepared. Similarly, a two-course tengu with a basis weight of 125 g / m ² was prepared and dyed. When the surface of this knitted fabric was observed, the yarn G accounted for 50% and the yarn H accounted for 50%. This fabric became discolored when wet.
[0029]
[Table 1]

[0031]
[Comparative Example 3]
Polyester fiber yarn containing 0.1% by weight of titanium oxide at 50d / 36f with warp, polyester fiber yarn containing 0.1% by weight of titanium oxide at 75d / 36f and weft and 3% by weight of titanium oxide at 75d / 24f One polyester fiber yarn contained was alternately arranged, and a plain woven fabric having a warp density of 140, a weft density of 85, and a basis weight of 93 g / m ² was prepared using a conventional loom, and dyeing and water absorption processing were performed. This fabric became discolored when wet.
[0032]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the discoloration of the fabric by rain or sweat can be prevented, As a result, the fabric without the discomfort based on the discoloration by water can be provided. The mixed fabric of the present invention had almost no troubles such as yarn breakage during the production of the raw material yarn and during the production of the fabric, and the processability was good.
[Brief description of the drawings]
FIG. 1 is a knitting diagram of a two-course tentacle knitted fabric showing an example of a mixed fabric.
FIG. 2 shows an example of a single yarn cross section of a W-shaped irregular cross-section fiber used in the discoloration-preventing mixed fabric of the present invention.
FIG. 3 shows an example of a triangular cross-section single fiber cross section of a fiber having a hollow portion used in the discoloration prevention mixed fabric of the present invention.

Claims

A plurality of yarns having different water diffusivities are mixed in a single layer, and the white pigment content is 1 to 6% by weight of a synthetic fiber and / or the white pigment content is 3 to 15% by weight. A yarn comprising a core-sheath type composite synthetic fiber having a core part of 2% by weight or less and a sheath part of 2% by weight or less is included as a constituent fiber of the mixed fabric, and the other fiber mixed with this fiber has a white pigment content of 1. It is a yarn comprising a synthetic fiber which is a hollow fiber or a modified cross-section yarn having a degree of irregularity of 1.4 or more and 2.2 or less, having at least 50% by weight in the mixed fabric. A discoloration-preventing mixed fabric characterized in that:

The mixed fabric according to claim 1, wherein the mixed fabric is a single circular knitted fabric, and is a circular knitted fabric knitted by alternately supplying yarns having different water diffusibility every course or every two courses.

A core-sheath type composite synthetic fiber having a yarn composed of a synthetic fiber having a white pigment content of 1 to 6% by weight and / or a core part having a white pigment content of 3 to 15% by weight and a sheath part of 2% by weight or less The mixed fabric according to claim 1 or 2, wherein the yarn comprises at least 20% by weight.

Water diffusion as defined herein for a synthetic fiber which is a hollow fiber or a modified cross-section yarn having a profile of 1.4 to 2.2 with a white pigment content of 1% by weight or more and water diffusibility The mixed fabric according to any one of claims 1 to 3, wherein the property value is 10 cm or more.