JP3949751B2

JP3949751B2 - Shoe insole and manufacturing method thereof

Info

Publication number: JP3949751B2
Application number: JP19167196A
Authority: JP
Inventors: 実真山; 健志重森; 幸夫中川
Original assignee: Asahi Kasei Chemicals Corp
Current assignee: Asahi Kasei Chemicals Corp
Priority date: 1996-07-03
Filing date: 1996-07-03
Publication date: 2007-07-25
Anticipated expiration: 2016-07-03
Also published as: JPH1014607A

Description

【０００１】
【発明の属する技術分野】
本発明は、靴の中敷き及びその製造方法に関する。更に詳しくは、連続気孔を持ち、吸湿性と吸水性を兼ね備えた靴の中敷きに関する。
【０００２】
【従来の技術】
従来、靴の中敷きとしては、防汚効果の他に、保温効果、脱臭効果、クッション効果等を目的としたものが知られている。
【０００３】
【発明が解決しようとする課題】
ところで、長時間に亙って靴を履いていると、発汗による蒸れを生じる。特に長靴、編み上げ靴のように、上部が閉鎖された靴の場合、それが一層顕著である。このような蒸れは不快感を与えるだけでなく、健康を損なう恐れもある。
【０００４】
上記蒸れの防止を図る上では、靴の中の湿気を吸収し、結露を生じた場合にはこれをも吸収できるよう、吸湿性と吸水性を兼ね備えた靴の中敷きが望ましい。とりわけ降雨地の雨水をも吸い取れるものが一層望ましい。
【０００５】
しかしながら、吸湿性と吸水性を兼ね備えた靴の中敷きは存在しないのが現状である。
【０００６】
本発明は、上記のような状況に鑑みてなされたもので、吸湿性と吸水性を兼ね備えた靴の中敷きを提供することを目的とする。
【０００７】
【課題を解決するための手段】
このために請求項１の発明では、部分α化澱粉、キチン、キトサン、活性アルミナ、シリカゲルから選ばれた１種以上からなる吸湿剤を保持した親水性樹脂が、芯材としての補強繊維構造体内に入り込みかつその表面の一部又は全部を覆っており、しかも片面から他面へ連続している気孔を有する靴の中敷きとしているものである。更に説明すると、請求項１の発明によれば、基本的には樹脂の成形品であることから、安価かつ容易に成形可能であり、しかも芯材として補強繊維構造体が設けられ、この補強繊維構造体内外に樹脂が一体化されているので、連続気孔を有するものではあるが、靴の中敷きとして必要な強度が得られるものである。また、親水性で連続気孔を有することによって吸水性が得られ、更に保持されている吸湿剤によって吸湿性が得られるものである。
【０００８】
また、請求項１６の発明では、親水性粉粒樹脂と、部分α化澱粉、キチン、キトサン、活性アルミナ、シリカゲルから選ばれた１種以上からなる粉粒状の吸湿剤との混合物を、補強繊維構造体内及びその両表面に位置させ、親水性粉粒樹脂の粒子間に隙間を残して燒結成形し、吸湿剤を保持した親水性樹脂が、芯材としての補強繊維構造体内に入り込みかつその表面の一部又は全部を覆い、しかも片面から他面へ連続している気孔を有する成形体とすることとしているものである。更に説明すると、請求項１６の発明によれば、補強繊維構造体の表面及びその内部において親水性粉粒樹脂が燒結されて強固に補強繊維構造体と一体化されると共に、粒子間に残された隙間によって連続気孔が形成され、しかも内表面及び外表面が親水性となるものである。また、親水性粉粒樹脂の融着時に、融着した親水性粉粒樹脂の粒子間に粉粒状の吸湿剤を保持させることができるものである。
【０００９】
【発明の実施の形態】
本発明の靴の中敷きは、芯材としての補強繊維構造体内に樹脂が入り込みかつ表面の一部又は全部を樹脂が覆っており、しかも連続気孔を有する樹脂成形品で、少なくとも内表面と外表面が親水性を有するものであれば、構成樹脂自体が親水性を有するものでも、構成樹脂自体は親水性を有しないものではあるが、スルフォン化、親水性モノマーのグラフト、特定の界面活性剤の添加、親水性の層を設ける等公知の方法で、全体又は少なくとも内表面と外表面を親水化したものでもよい。中でも内部に非親水性の樹脂を残しつつ内表面と外表面を親水化したものとすると、吸水・吸湿時に内部の非親水性の樹脂部分は水分を吸収しないため、寸法安定性に優れるので好ましい。
【００１０】
連続気孔を形成するには、例えば発泡成形、燒結成形等の手法が主に用いられるが、その他に例えば抽出可能な成分と共に溶融させた樹脂で成形体を得た後、抽出可能な成分を抽出して連続気孔を形成することも可能である。中でも、燒結成形は、粉粒状の樹脂を希望の形状に堆積若しくは金型中に充填し、粒子間に隙間を残しつつ、加圧又は無加圧状態で粒子相互を加熱融着することで、連続気孔を容易に形成できるので、最も好ましい。本発明の靴の中敷きにおける気孔は、全体が均一な寸法であってもよいし、例えば表層と内部、或いは一方の表層と他方の表層とで気孔の寸法を変えたものでもよい。尚、連続気孔とは、片面から他面へ連続している気孔をいう。この気孔は直線的でも曲線的でもよい。
【００１１】
燒結成形によって本発明の靴の中敷きを得る場合、上記のように、粉粒状の樹脂を用いて成形が行われるがことになる。この場合の粉粒状の樹脂は、それ自体が親水性を有するものでもよいし、それ自体は親水性を有さないが、スルフォン化、親水性モノマーのグラフト、特定の界面活性剤の添加、親水性の層を設ける等公知の方法で親水化された親水性粉粒樹脂であることが好ましい。中でも非親水性の樹脂の粉粒体の表面だけを親水化した親水性粉粒樹脂は、これを燒結することによって、内部に非親水性の樹脂を残しつつ内表面と外表面を親水化したものとなることから好ましい。
【００１２】
燒結成形に用いられる粉粒状の樹脂は、重合により得られた粉粒状の樹脂をそのまま用いることも可能であるし、一度粉粒状以外の形状に賦形したものを、機械粉砕、冷凍粉砕、化学粉砕等の公知の方法で粉粒状にしたものを用いることもできる。これらの粉粒状の樹脂は、平均粒径が５〜２０００μｍであることが好ましく、更に好ましくは５０〜１０００μｍである。粉粒状の樹脂の平均粒径が５μｍ未満では、燒結体にした時に全体が密になり過ぎ、十分な吸水量が得にくくなる。また、粉粒状の樹脂の平均粒径が２０００μｍを超えると、毛細管現象による水の吸い上げ力が小さくなりやすくなる。尚、上記平均粒径とは、ＪＩＳ・Ｚ８８０１のふるいを使用し、ふるい分け試験通則ＪＩＳ・Ｚ８８１５に従ってふるい分けし、算術目盛りによって積算ふるいした百分率を図で表わし、積算量５０％の粒子径をいう。
【００１３】
本発明の靴の中敷きを燒結成形する場合、上記平均粒径の親水性粉粒樹脂と後述する粉粒状の吸湿剤とを後述の割合で混合した材料を用いて行うのが最も好ましい。燒結成形は、後述する芯材としての補強繊維構造体内と両表面に上記混合物が位置するよう、両者を金型に充填するか平面上に載置して、親水性粉粒状樹脂の融点以上に加熱することで行うことができる。また、燒結成形は、無加圧下で行ってもよいが、必要に応じて適宜加圧してもよい。
【００１４】
発明の靴の中敷きを構成する樹脂の具体例としては、例えば、セルロース系等の天然樹脂の他に、フェノール樹脂、ユリア樹脂、メラミン樹脂、ポリエステル、アリル樹脂、エポキシ樹脂等に代表される熱硬化性樹脂、ポリ塩化ビニル、ポリエチレン、ポリプロピレン、ポリスチレン、ポリメチルメタアクリレート、ポリアミド、ポリアセタール、ポリカーボネート等に代表される熱可塑性樹脂が挙げられる。
【００１５】
これらの中でも、賦形性、二次加工性等を考慮すると、熱可塑性樹脂がよい。
更に、熱可塑性樹脂の中でも、安価であること、耐薬品性に優れること、加工性に優れること、素材の吸湿性・吸水性が低いことにより吸水時の寸法安定性に優れること等から、ポリエチレン、ポリプロピレンに代表されるポリオレフィン系樹脂が好ましい。
【００１６】
ポリオレフィン系樹脂としては、エチレンの単独重合体、エチレンとプロピレン、ブテン−１、ヘキセン−１、オクテン−１のような１種以上のαオレフィンとの共重合体、エチレンと酢酸ビニル、アクリル酸、メタアクリル酸、アクリル酸エステル、メタアクリル酸エステル等との共重合体、プロピレンの単独重合体、プロピレンとエチレン、ブテン−１の様な１種以上のαオレフィンとの共重合体等が挙げられる。中でも、燒結成形に適した粉粒体を得やすいこと、燒結成形が容易であること、耐薬品性に優れること、素材自身の吸湿吸水性が低いこと等の理由から、ポリエチレンが好ましい。
【００１７】
ポリエチレンは、それ自身は親水性を示さないから、スルフォン化、親水性モノマーのグラフト、特定の界面活性剤の添加、親水性の層を設ける等公知の方法で親水化処理を施すことになる。特に、特願昭５７−２７４００号公報、特願昭５７−３２４２８号公報、特願昭６３−６１９８１号公報、特願昭６３−６７０７８号公報等に開示された方法で親水化すると、容易に表面のみを親水化した親水性粉粒樹脂を得ることができ、これを燒結することによって、吸湿若しくは吸水した場合に、連続気孔部分のみ水分が存在し、素材自身は吸湿・吸水することがないので、吸湿・吸水時の強度変化や寸法変化のない本発明の靴の中敷きが得られる。
【００１８】
ポリエチレンのメルトインデックス（ＭＩ）は、０．００１〜３０ｇ／１０分ののものがよく、より好ましくは０．０１〜１０ｇ／１０分である。連続気孔を形成する手段として燒結成形を考えた場合、ＭＩが０．００１ｇ／１０分以下では、燒結成形したときに隣り合う粒子の融着強度が低いため、靴の中敷きとしての強度が弱くなりやすい。ＭＩが３０ｇ／１０分以上では、燒結成形を行ったときに樹脂の溶融と共に流動が起こり、気孔の形成を妨げやすくなる。尚、ＭＩは、ＪＩＳ・Ｋ７２１０に基づき、温度１９０℃、荷重２．１６ｋｇで測定した値である。
【００１９】
また、ポリエチレンの密度は、０．９０〜０．９７ｇ／ｃｃであることが好ましい。密度が０．９０ｇ／ｃｃ以下では柔軟性に富むが、耐薬品性に劣ることと、融点が低くなって成形可能範囲が狭くなりやすい。
【００２０】
本発明の靴の中敷きは、芯材である補強繊維構造体と、吸湿剤を含有する樹脂多孔質体とで構成されているものである。吸湿剤を含有する樹脂多孔質体の形成は、吸湿剤を混合した素材を用いて前記連続気孔の形成を行うことで容易に行うことができる。
【００２１】
本発明に用いる吸湿剤は、吸湿後に大きな強度変化や寸法変化が無く、また水分によって化学的な変化を起こさないものがよい。吸湿後に大きな強度変化、例えば崩壊等が起こると、吸湿剤が連続気孔を通って外部に排出され、周囲を汚染しやすくなる。また、吸湿後に大きな寸法変化、例えば大きな膨潤があると、連続気孔を閉塞したり、連続気孔を通って外部にはみ出したりする不都合を生じやすくなる。これらのことから、吸湿剤としては、部分α化澱粉、キチン、キトサン、シリカゲルの群から選ばれた１種以上のものが好ましい。これらは粉粒状で入手できるので粉粒状の樹脂と混合して、例えば燒結成形等により賦形することも可能であるし、吸湿・吸水後も大きな寸法変化をもたらさない。これら吸湿剤は、樹脂１００重量部に対して３〜７０重量部保持されていることが好ましい。３重量部以下であると実質的な吸湿性能が得にくく、７０重量部以上では本発明の靴の中敷きの強度が弱くなりやすい。尚、吸湿剤は本発明の靴の中敷きの中に均一に存在してもよいし、不均一に存在してもよい。また、前記のような燒結成形を行う場合、吸湿剤は、その平均粒径が親水性粉粒樹脂の平均粒径の１／３〜３倍であることが好ましい。平均粒径が小さ過ぎると脱落を生じやすく、逆に大き過ぎると本発明の靴の中敷きの強度が低下しやすくなる。
【００２２】
本発明の靴の中敷きは、上記吸湿剤と共に、防かび剤及び／又は抗菌剤を、樹脂１００重量部に対して０．０５〜２重量部保持していることが好ましい。但し、上記吸湿剤との合計量が、本発明の靴の中敷きを構成している樹脂１００重量部に対して７０重量部を超えない範囲であることが好ましい。また、燒結成形に際しては、吸湿剤と共に親水性粉粒樹脂と混合することが好ましく、吸湿剤と同様の平均粒径であることが好ましい。防かび剤としては、チアベンダゾール系、キチン、キトサンから選ばれた１種以上が好ましい。また、抗菌剤としては、無機系抗菌剤、キチン、キトサンから選ばれた１種以上が好ましい。無機系抗菌剤としては、例えば、ゼオライト、ＳｉＯ₂ 、Ａｌ₂ Ｏ₃ 、ＭｇＯ等の無機物にＡｇ及び／又はＺｎを担持させたものがよい。尚、防かび剤及び／又は抗菌剤としてキトサンを用いる場合には、蟻酸、酢酸、乳酸の様な有機酸或いは塩酸の様な無機酸に溶解するか、これらの酸との塩にして使用してもよい。
【００２３】
本発明において、芯材である補強繊維構造体としては、内部に樹脂が入り込んだ状態で連続気孔を形成できる目の荒さを備えたものであれば、例えば目の粗い編み物、網状物、目の粗いパイル織物等を用いることが可能である。また、この補強繊維構造体は、天然繊維製でも合成繊維製でもよいが、高い耐衝撃性、機械的強度が得やすいことから、合成繊維製であることが好ましい。特に本発明の靴の中敷きを燒結成形で得る場合には、粉粒状の樹脂が容易に入り込める目の粗さを有し、しかも粉粒状の樹脂よりも融点の高い合成繊維製とし、燒結成形温度を、粉粒状の樹脂の融点以上でこの補強繊維構造体の構成繊維の融点以下に定めることが好ましい。補強繊維構造体を構成する合成繊維としては、例えばポリエステル系繊維、ポリアミド系繊維、アラミド繊維、ポリアクリロニトリル系繊維、ポリオレフィン系繊維、レーヨン系繊維等が挙げられ、その繊維太さは５０〜１０００デニールであることが好ましい。
【００２４】
補強繊維構造体としては、立体構造を持つものが特に好ましい。この立体構造を持つ補強繊維構造体としては、表裏２枚の地組織と、該地組織を連結する壁状の連結部からなる立体構造を有する繊維構造体であって、該壁状の連結部は表裏２枚の地組織を結合する糸条から成り、前記地組織が繊維占有率が１０〜８０％（繊維が占める面積比）であるように複数の糸によって形成され、それによって前記繊維構造体に表裏に連通する複数の空隙が各壁状の連結部間に設けられているものであることが好ましい。具体的には、特公平５−１８９３９号公報に開示された繊維構造体で、二層構造を有する布帛状物を製造できる製造装置によって容易に製造することができる。例えば、二重繊維機、二重の針床を有する経編機等を用いて容易に製造できる。
【００２５】
更に、燒結成形による本発明の靴の中敷きに適した立体構造を持つ補強繊維構造体について説明すると、図１に示されるように、表裏の地組織１，２はハニカム状、網目状、目の粗い編み物状であり、この両地組織１，２を離して保持しつつ結合する、壁状の連結部を構成する糸条３によって立体性が付与された繊維構造体が好ましい。また、燒結成形に用いる粉粒状の樹脂が容易に内部に入り込めるよう、表裏の地組織１，２の開孔部の寸法及び糸条３によって離される両地組織１，２の間隔と糸条３とが形成する開孔部の寸法のいずれか又は全部が、粉粒状の樹脂の前記平均粒径の１〜１００倍であることが好ましい。このような繊維構造体を補強繊維構造体として用いると、本発明の靴の中敷きの厚み方向のほぼ全体に亙って樹脂と補強繊維構造体を容易に複合化させることができ、強度的に優れるだけでなく、補強繊維構造体の厚み等を適宜選択することで、適度なクッション性を付与することができる。
【００２６】
本発明の靴の中敷きは、表面或いは内部に、前記補強繊維構造体とは別の布、織物、編み物、不織布、穴あきフィルム、金網等、本発明の多孔性を阻害しないものとの更なる複合化も可能である。また、一部分に非透湿性或いは非透水性のフィルム、膜等を設けて、吸収した水分の影響を周囲に及ぼさないようにすることも可能である。更には、着色、印刷等により意匠性を持たせることも可能であり、熱安定剤、耐候剤、吸臭剤、脱臭剤、香料等を必要に応じて添加して形成してもよい。これら添加剤を加える際には流動パラフィン等の展着剤を用いることもできる。
【００２７】
本発明の靴の中敷きは、予めその形状をした金型で成形したものでもよいし、平板状に成形した後打ち抜き加工等で所定の形状としたものでもよい。
【００２８】
本発明の靴の中敷きは、常温にて当該中敷きを水深１０ｍｍの水中に垂直に立てた場合に、毛細管現象によって、浸漬後１分で水面から１０ｍｍ以上、中敷き内を水が水面より上部に上昇する吸水力を有することが好ましい。
【００２９】
本発明の靴の中敷きは、その気孔率が３０〜８０％であることが好ましい。気孔率が３０％以下では実質的に多孔体としての機能を発揮しにくく、８０％以上では成形体の強度が低くなりやすい。ここでいう気孔率は次式で算出される値をいう。
【００３０】
気孔率（％）＝［（真の密度−見掛けの密度）／真の密度］×１００
尚、気孔率は靴の中敷き全体に均一でもよいし、不均一でもよい。
【００３１】
本発明の靴の中敷きは、乾燥状態で当該中敷き１ｇ当たり０．５ｇ以上の水を吸収するものであることが好ましい。吸水量が１ｇ当り０．５ｇ以下では実用的な吸水性となりにくい。尚、吸水量は、中敷きを乾燥して重量を量り、次いで水中に５分間浸漬した後水中より引き上げて重量を測定し、乾燥時の重量と水中浸漬後の重量の差を乾燥時の重量で除した値をいう。
【００３２】
本発明の靴の中敷きは、乾燥状態で当該中敷き１ｇ当たり０．０１ｇ以上吸湿するものであることが好ましい。吸湿量が１ｇ当り０．０１ｇ以下では実用的な吸湿性となりにくい。尚、吸湿量は、中敷きを乾燥して重量を量り、次いで４０℃、９０％ＲＨの雰囲気下に１．５時間放置した後重量を測定し、乾燥時の重量と吸湿後の重量の差を乾燥時の重量で除した値をいう。
【００３３】
本発明の靴の中敷きは、吸水後の寸法変化率が０．５％以下であることが好ましい。寸法変化が０．５％以上になると、靴と大きさが合わなくなりやすい。尚、寸法変化率は、成形体を２３℃の雰囲気下で水中に２４時間浸漬し、浸漬前後の寸法の差の浸漬前の寸法に対する割合をいう。
【００３４】
【実施例】
以下実施例により本発明を具体的に説明する。
【００３５】
実施例１〜３
ＪＩＳ・Ｋ７２１０（条件：温度１９０℃、荷重２．１６Ｋｇ）によって測定したＭＩが０．０６ｇ／１０分、密度が０．９５６ｇ／ｃｃ、平均粒径が１４０μｍの高密度ポリエチレン粉体（商品名「サンファイン・ＳＨ８１０」、旭化成工業株式会社製）１００重量部にポリグリセリンイソステアリルエステル０．３重量部を高速ミキサーにて混合し、親水性粉粒樹脂を得た。該親水性粉粒樹脂に吸湿剤として平均粒径７０μｍの部分α化澱粉（商品名「ＰＣＳ」、旭化成工業株式会社製）を表１に示す割合で混合した。
【００３６】
２００×４００×３ｍｍの空間を有するアルミニウム製の金型内に、特公平５−１８９３９号公報に記載の方法により、１５０デニールのポリエステル繊維と、１８０デニールのポリアミドモノフィラメントで作られた立体構造を持つ補強繊維構造体を装着し、その中に前記混合物を充填した。次いで、金型をその表面温度が１４０〜１５０℃になるまで加熱した後、室温まで冷却してシートとして取り出した。このシートから打ち抜きにより靴の中敷きを得た。該中敷きの物性を表１に示す。尚、履き心地は、靴の中に装着し、１日履いた時の靴の蒸れ感を評価したものであり、○は蒸れなし、×は蒸れありを意味する。
【００３７】
比較例１
実施例１で使用した高密度ポリエチレン粉末に実施例１で使用した吸湿剤を５０重量部混合した。２００×４００×３ｍｍの空間を持つアルミニウム製の金型内に、実施例１で使用した立体構造を持つ補強繊維構造体を装着し、その中に前記混合物を充填した。次いで、金型をその表面温度が１４０〜１５０℃になるまで加熱した後、室温まで冷却してシートとして取り出した。このシートから打ち抜きによって中敷きを得た。該中敷きの物性を表１に示す。
【００３８】
比較例２
２００×４００×３ｍｍの空間を持つアルミニウム製の金型内に、実施例１で使用した立体構造を持つ補強繊維構造体を装着し、その中に実施例１で使用した親水性粉粒樹脂を充填した。次いで、金型をその表面温度が１４０〜１５０℃になるまで加熱した後、室温まで冷却してシートとして取り出した。このシートから打ち抜きによって中敷きを得た。該中敷きの物性を表１に示す。
【００３９】
実施例４
実施例１で使用した親水性粉粒樹脂１００重量部に吸湿剤として平均粒径５０μｍのキトサンを１０重量部混合した。２００×４００×３ｍｍの空間を持つアルミニウム製の金型内に、実施例１で使用した立体構造を持つ補強繊維構造体を装着し、その中に前記混合物を充填した。次いで、金型をその表面温度が１４０〜１５０℃になるまで加熱した後、室温まで冷却してシートとして取り出した。このシートから打ち抜きによって中敷きを得た。該中敷きの物性を表１に示す。
【００４０】
【表１】

【００４１】
【発明の効果】
本発明の靴の中敷きは、吸湿性と吸水性を兼ね備えていることから、靴の中の湿気を吸収して蒸れにくくすると共に、万一結露を生じた時にはこれを吸収してしまうので、長時間に亙って靴を履いていても蒸れ感のない良好な履き心地が得られるものである。また、降雨時には雨水をも吸収できるので、雨水による濡れ感も防止できるものである。
【図面の簡単な説明】
【図１】本発明に用いる立体構造を持つ補強繊維構造体の好ましい例の説明図である。
【符号の説明】
１，２地組織
３壁状の連結部を構成する糸条[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shoe insole and a method for manufacturing the same. More specifically, the present invention relates to an insole for shoes having continuous pores and having both moisture absorption and water absorption.
[0002]
[Prior art]
Conventionally, as an insole for shoes, in addition to an antifouling effect, those intended for a heat retaining effect, a deodorizing effect, a cushioning effect and the like are known.
[0003]
[Problems to be solved by the invention]
By the way, if you wear shoes for a long time, you will sweat due to sweating. This is especially true for shoes with closed tops, such as boots and braided shoes. Such stuffiness is not only uncomfortable, but it can also harm your health.
[0004]
In order to prevent the above-mentioned stuffiness, it is desirable that the insole of the shoe has both moisture absorption and water absorption so as to absorb moisture in the shoe and also absorb the condensation when it occurs. In particular, it is more desirable to be able to absorb rainwater from rainy areas.
[0005]
However, there is currently no insole for shoes that has both hygroscopicity and water absorption.
[0006]
The present invention has been made in view of the above situation, and an object thereof is to provide an insole for shoes having both hygroscopicity and water absorption.
[0007]
[Means for Solving the Problems]
For this reason, in the invention of claim 1, the hydrophilic resin holding a hygroscopic agent selected from partially pregelatinized starch, chitin, chitosan, activated alumina, and silica gel is used as the core in the reinforcing fiber structure. It is a shoe insole that has pores that penetrate and cover part or all of its surface and that continue from one side to the other . More specifically, according to the invention of claim 1, since it is basically a molded product of resin, it can be molded inexpensively and easily, and a reinforcing fiber structure is provided as a core material. Since the resin is integrated inside and outside the structure, it has continuous pores but can provide the strength required for the insole of shoes. Further, it is hydrophilic and has continuous pores, so that water absorption is obtained, and hygroscopicity is obtained by the retained moisture absorbent.
[0008]
Further, in the invention of claim 16, and a hydrophilic particulate resin, partially α-starch, chitin, chitosan, activated alumina, a mixture of a moisture absorbent particulate comprising one or more selected from silica gel, reinforcing fibers The hydrophilic resin, which is positioned in the structure and on both surfaces thereof, is sintered and formed with a gap between the particles of the hydrophilic granular resin, and the moisture absorbent is retained, enters the reinforcing fiber structure as the core material and its surface The molded body has a pore that covers part or all of the surface and that is continuous from one side to the other side . More specifically, according to the invention of claim 16 , the hydrophilic granular resin is sintered on the surface of the reinforcing fiber structure and inside thereof, and is firmly integrated with the reinforcing fiber structure, and is left between the particles. A continuous pore is formed by the gap, and the inner surface and the outer surface become hydrophilic. Further, when the hydrophilic granular resin is fused, a granular hygroscopic agent can be held between the fused hydrophilic granular resin particles.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The insole of the shoe of the present invention is a resin molded product in which a resin enters a reinforcing fiber structure as a core material and covers a part or all of the surface, and has continuous pores, at least an inner surface and an outer surface If the component resin is hydrophilic, the component resin itself is hydrophilic, but the component resin itself does not have hydrophilicity, but sulfonation, grafting of hydrophilic monomers, specific surfactants The whole or at least the inner surface and the outer surface may be made hydrophilic by a known method such as addition or formation of a hydrophilic layer. Above all, it is preferable to make the inner surface and the outer surface hydrophilic while leaving the non-hydrophilic resin inside, because the non-hydrophilic resin portion inside absorbs moisture at the time of water absorption / moisture absorption and is excellent in dimensional stability. .
[0010]
For forming continuous pores, methods such as foam molding and sintering molding are mainly used. However, for example, after obtaining a molded body with a resin melted together with extractable components, extractable components are extracted. Thus, it is also possible to form continuous pores. Among these, sintering molding is a method of depositing powdery resin in a desired shape or filling a mold and heating and fusing particles in a pressurized or non-pressurized state while leaving a gap between the particles. Most preferred because continuous pores can be easily formed. The pores in the insole of the shoe of the present invention may have a uniform size as a whole, or may be ones in which the pore size is changed between the surface layer and the inside, or one surface layer and the other surface layer, for example. The continuous pores are pores that are continuous from one side to the other side. The pores may be straight or curved.
[0011]
When the insole of the shoe of the present invention is obtained by sinter molding, the molding is performed using a powdered resin as described above. In this case, the powdery resin may be hydrophilic in itself, or itself is not hydrophilic, but is sulfonated, grafted with a hydrophilic monomer, added with a specific surfactant, hydrophilic It is preferably a hydrophilic granular resin that has been hydrophilized by a known method such as providing a conductive layer. Among these, the hydrophilic granular resin in which only the surface of the non-hydrophilic resin powder is hydrophilized, the inner surface and the outer surface are made hydrophilic while leaving the non-hydrophilic resin inside by sintering this. It is preferable because it becomes a thing.
[0012]
The granular resin used in the sintering molding can be the granular resin obtained by polymerization as it is, or once shaped into a shape other than granular, machine pulverization, freeze pulverization, chemical What was pulverized by well-known methods, such as grinding | pulverization, can also be used. These powdery resins preferably have an average particle size of 5 to 2000 μm, more preferably 50 to 1000 μm. When the average particle size of the powdery resin is less than 5 μm, the whole becomes too dense when formed into a sintered body, and it becomes difficult to obtain a sufficient amount of water absorption. On the other hand, when the average particle size of the powdery resin exceeds 2000 μm, the water suction force due to the capillary phenomenon tends to be small. The above average particle diameter means a particle diameter of 50% of the cumulative amount, using a JIS / Z8801 sieve, sieving according to the general rule of screening test JIS / Z8815, and showing the percentage of the cumulative sieve on the arithmetic scale.
[0013]
When the insole of the shoe of the present invention is sintered, it is most preferable to use a material obtained by mixing the hydrophilic particle resin having the above average particle diameter and a granular hygroscopic agent described later at a ratio described later. Sintering is performed by filling the mold in a mold or placing it on a flat surface so that the mixture is located on the reinforcing fiber structure as a core material and both surfaces described later, and above the melting point of the hydrophilic granular resin. This can be done by heating. Sintering may be performed under no pressure, but may be appropriately pressurized as necessary.
[0014]
Specific examples of the resin constituting the insole of the invention include, for example, thermosetting typified by phenol resin, urea resin, melamine resin, polyester, allyl resin, epoxy resin, etc. in addition to natural resins such as cellulose Thermoplastic resins typified by water-soluble resins, polyvinyl chloride, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyamide, polyacetal, polycarbonate and the like.
[0015]
Among these, a thermoplastic resin is preferable in consideration of formability and secondary processability.
Furthermore, among thermoplastic resins, it is inexpensive, has excellent chemical resistance, has excellent processability, and has excellent dimensional stability during water absorption due to its low hygroscopicity and water absorption properties. Polyolefin resins typified by polypropylene are preferred.
[0016]
Examples of polyolefin resins include ethylene homopolymers, copolymers of ethylene and one or more α-olefins such as propylene, butene-1, hexene-1 and octene-1, ethylene and vinyl acetate, acrylic acid, Examples thereof include copolymers with methacrylic acid, acrylic acid esters, methacrylic acid esters, and the like, homopolymers of propylene, copolymers of propylene and one or more α-olefins such as ethylene and butene-1. . Among these, polyethylene is preferable because it is easy to obtain a powder suitable for sinter molding, is easy to sinter molding, has excellent chemical resistance, and has a low hygroscopic water absorption property.
[0017]
Since polyethylene itself does not exhibit hydrophilicity, it is subjected to a hydrophilic treatment by a known method such as sulfonation, grafting of a hydrophilic monomer, addition of a specific surfactant, or formation of a hydrophilic layer. In particular, when hydrophilized by the methods disclosed in Japanese Patent Application Nos. 57-27400, 57-32428, 63-61981, 63-67078, etc., A hydrophilic granular resin with only the surface made hydrophilic can be obtained. By sintering this resin, moisture is present only in the continuous pores when moisture is absorbed or absorbed, and the material itself does not absorb moisture. Therefore, the insole of the shoe of the present invention can be obtained without any change in strength or change in dimensions during moisture absorption or water absorption.
[0018]
The melt index (MI) of polyethylene is preferably 0.001 to 30 g / 10 min, more preferably 0.01 to 10 g / 10 min. Considering sintering molding as a means for forming continuous pores, if MI is 0.001 g / 10 min or less, the fusion strength of adjacent particles is low when sintering molding, so the strength as an insole for shoes becomes weak. Cheap. When MI is 30 g / 10 min or more, when sintering is performed, flow occurs with the melting of the resin, and the formation of pores tends to be hindered. MI is a value measured at a temperature of 190 ° C. and a load of 2.16 kg based on JIS · K7210.
[0019]
Moreover, it is preferable that the density of polyethylene is 0.90-0.97 g / cc. When the density is 0.90 g / cc or less, it is rich in flexibility, but it is poor in chemical resistance, and the melting point becomes low, and the moldable range tends to be narrow.
[0020]
The insole of the shoe of the present invention is composed of a reinforcing fiber structure as a core material and a resin porous body containing a hygroscopic agent. Formation of the porous resin body containing the hygroscopic agent can be easily performed by forming the continuous pores using a material mixed with the hygroscopic agent.
[0021]
The hygroscopic agent used in the present invention preferably has no significant change in strength or size after moisture absorption and does not cause a chemical change due to moisture. When a large strength change such as collapse occurs after moisture absorption, the hygroscopic agent is discharged to the outside through the continuous pores, and the surroundings are easily contaminated. In addition, if there is a large dimensional change after moisture absorption, for example, a large swelling, it is likely to cause inconvenience that the continuous pores are blocked or protruded outside through the continuous pores. For these reasons, the hygroscopic agent is preferably at least one selected from the group consisting of partially pregelatinized starch, chitin, chitosan and silica gel. Since these can be obtained in the form of powder, they can be mixed with powdered resin and shaped by, for example, sinter molding or the like, and do not cause a large dimensional change even after moisture absorption and water absorption. These hygroscopic agents are preferably held in an amount of 3 to 70 parts by weight with respect to 100 parts by weight of the resin. If it is 3 parts by weight or less, it is difficult to obtain a substantial hygroscopic performance, and if it is 70 parts by weight or more, the insole strength of the shoe of the present invention tends to be weak. The hygroscopic agent may be present uniformly or non-uniformly in the insole of the shoe of the present invention. Moreover, when performing sintering molding as described above, the hygroscopic agent preferably has an average particle size of 1/3 to 3 times the average particle size of the hydrophilic granular resin. If the average particle size is too small, it is easy to drop off, and if too large, the strength of the insole of the shoe of the present invention tends to decrease.
[0022]
The insole of the shoe of the present invention preferably retains a fungicide and / or an antibacterial agent together with the hygroscopic agent in an amount of 0.05 to 2 parts by weight with respect to 100 parts by weight of the resin. However, the total amount of the above hygroscopic agent is preferably in a range not exceeding 70 parts by weight with respect to 100 parts by weight of the resin constituting the insole of the shoe of the present invention. In the sintering molding, it is preferable to mix with a hydrophilic powder resin together with a hygroscopic agent, and it is preferable that the average particle diameter is the same as that of the hygroscopic agent. As the fungicide, one or more selected from thiabendazole, chitin, and chitosan are preferable. Moreover, as an antibacterial agent, 1 or more types chosen from the inorganic type antibacterial agent, chitin, and chitosan are preferable. As the inorganic antibacterial agent, for example, an inorganic substance such as zeolite, SiO ₂ , Al ₂ O ₃ , MgO or the like that supports Ag and / or Zn is preferable. When chitosan is used as an antifungal agent and / or antibacterial agent, it can be dissolved in an organic acid such as formic acid, acetic acid or lactic acid or an inorganic acid such as hydrochloric acid, or used as a salt with these acids. May be.
[0023]
In the present invention, the reinforcing fiber structure that is a core material may be, for example, a coarse knitted fabric, a net-like material, or an eye shape, as long as it has a rough surface that allows continuous pores to be formed in a state where a resin enters the inside. A coarse pile fabric or the like can be used. The reinforcing fiber structure may be made of natural fibers or synthetic fibers, but is preferably made of synthetic fibers because high impact resistance and mechanical strength can be easily obtained. In particular, when the insole of the shoe of the present invention is obtained by sintering molding, it is made of a synthetic fiber having a coarseness that allows the powdered resin to easily enter and has a melting point higher than that of the powdered resin, and the sintering molding temperature. Is preferably not less than the melting point of the granular resin and not more than the melting point of the constituent fibers of the reinforcing fiber structure. Examples of the synthetic fibers constituting the reinforcing fiber structure include polyester fibers, polyamide fibers, aramid fibers, polyacrylonitrile fibers, polyolefin fibers, rayon fibers, and the fiber thickness is 50 to 1000 denier. It is preferable that
[0024]
As the reinforcing fiber structure, one having a three-dimensional structure is particularly preferable. The reinforcing fiber structure having this three-dimensional structure is a fiber structure having a three-dimensional structure comprising two ground structures on the front and back sides and a wall-shaped connecting part for connecting the ground structure, the wall-shaped connecting part. Is formed of a plurality of yarns so that the ground structure has a fiber occupancy of 10 to 80% (area ratio occupied by the fiber). It is preferable that a plurality of voids communicating with the body on the front and back sides are provided between the wall-like connecting portions. Specifically, the fiber structure disclosed in Japanese Patent Publication No. 5-18939 can be easily manufactured by a manufacturing apparatus capable of manufacturing a fabric-like product having a two-layer structure. For example, it can be easily manufactured using a double fiber machine, a warp knitting machine having a double needle bed, or the like.
[0025]
Further, the reinforcing fiber structure having a three-dimensional structure suitable for the insole of the shoe of the present invention by sinter molding will be described. As shown in FIG. 1, the

ground structures

1 and 2 on the front and back sides are honeycomb-like, mesh-like, A fiber structure that has a rough knitting shape and is imparted with three-dimensionality by the yarn 3 constituting the wall-like connecting portion that is bonded while holding the

ground structures

1 and 2 apart is preferable. Further, the size of the opening portions of the front and

back ground structures

1, 2 and the distance between the

ground structures

1, 2 separated by the yarn 3 and the yarn 3 so that the powdery resin used for sintering molding can easily enter the inside. It is preferable that any or all of the dimensions of the apertures formed by and are 1 to 100 times the average particle diameter of the granular resin. When such a fiber structure is used as a reinforcing fiber structure, the resin and the reinforcing fiber structure can be easily combined over almost the entire thickness direction of the insole of the shoe of the present invention. Not only is it excellent, but appropriate cushioning properties can be imparted by appropriately selecting the thickness and the like of the reinforcing fiber structure.
[0026]
The insole of the shoe of the present invention is further provided with a cloth, a woven fabric, a knitted fabric, a non-woven fabric, a perforated film, a wire mesh, or the like that does not hinder the porosity of the present invention on the surface or inside thereof. Compounding is also possible. Further, it is possible to provide a part of the film with a moisture-impermeable or water-impermeable film, a film, or the like so that the influence of absorbed moisture does not affect the surroundings. Furthermore, it is possible to impart design properties by coloring, printing, and the like, and a heat stabilizer, weathering agent, odorant, deodorant, fragrance and the like may be added as necessary. When these additives are added, a spreading agent such as liquid paraffin can be used.
[0027]
The insole of the shoe of the present invention may be formed in advance with a mold having the shape, or may be formed into a predetermined shape by stamping after being formed into a flat plate shape.
[0028]
When the insole of the present invention is standing vertically in water with a water depth of 10 mm at room temperature, the insole of the shoe rises 10 mm or more from the water surface after immersion for 1 minute, and the water in the insole rises above the water surface due to capillary action. It is preferable to have a water absorbing power.
[0029]
The insole of the shoe of the present invention preferably has a porosity of 30 to 80%. When the porosity is 30% or less, the function as a porous body is hardly exhibited. When the porosity is 80% or more, the strength of the molded body tends to be low. The porosity here means a value calculated by the following equation.
[0030]
Porosity (%) = [(true density−apparent density) / true density] × 100
The porosity may be uniform or non-uniform throughout the insole of the shoe.
[0031]
The insole of the shoe of the present invention preferably absorbs 0.5 g or more of water per 1 g of the insole in a dry state. When the water absorption is 0.5 g or less per gram, it is difficult to achieve practical water absorption. The amount of water absorption is measured by drying the insole, weighing it, then immersing it in water for 5 minutes, then pulling it up from the water and measuring the weight. The value divided by.
[0032]
The insole of the shoe of the present invention preferably absorbs 0.01 g or more per gram of the insole in a dry state. When the moisture absorption amount is 0.01 g or less per gram, it is difficult to achieve practical hygroscopicity. The moisture absorption amount is measured by drying the insole and then weighing it after leaving it in an atmosphere of 40 ° C. and 90% RH for 1.5 hours to determine the difference between the weight after drying and the weight after moisture absorption. The value divided by the weight at the time of drying.
[0033]
The insole of the shoe of the present invention preferably has a dimensional change rate of 0.5% or less after water absorption. If the dimensional change is 0.5% or more, the size of the shoe is likely not to match. In addition, a dimensional change rate means the ratio with respect to the dimension before immersion of the difference of the dimension before and behind immersion, when a molded object is immersed in water for 24 hours in 23 degreeC atmosphere.
[0034]
【Example】
The present invention will be specifically described below with reference to examples.
[0035]
Examples 1-3
High-density polyethylene powder (trade name: “MI” measured by JIS K7210 (conditions: temperature 190 ° C., load 2.16 Kg) with an MI of 0.06 g / 10 min, a density of 0.956 g / cc, and an average particle size of 140 μm. Sun Fine SH810 "(manufactured by Asahi Kasei Kogyo Co., Ltd.) 100 parts by weight of polyglycerin isostearyl ester was mixed with a high-speed mixer to obtain a hydrophilic granular resin. Partially pregelatinized starch (trade name “PCS”, manufactured by Asahi Kasei Kogyo Co., Ltd.) having an average particle size of 70 μm as a hygroscopic agent was mixed with the hydrophilic granular resin at a ratio shown in Table 1.
[0036]
A three-dimensional structure made of 150 denier polyester fiber and 180 denier polyamide monofilament is formed in an aluminum mold having a space of 200 × 400 × 3 mm by the method described in Japanese Patent Publication No. 5-18939. A reinforcing fiber structure was mounted, and the mixture was filled therein. Next, the mold was heated until its surface temperature reached 140 to 150 ° C., then cooled to room temperature and taken out as a sheet. Shoe insole was obtained by punching from this sheet. Table 1 shows the physical properties of the insole. Note that the comfort is an evaluation of the stuffiness of the shoe when worn in a shoe and worn for one day, ○ means no stuffiness, and x means stuffiness.
[0037]
Comparative Example 1
50 parts by weight of the hygroscopic agent used in Example 1 was mixed with the high-density polyethylene powder used in Example 1. A reinforcing fiber structure having a three-dimensional structure used in Example 1 was mounted in an aluminum mold having a space of 200 × 400 × 3 mm, and the mixture was filled therein. Next, the mold was heated until its surface temperature reached 140 to 150 ° C., then cooled to room temperature and taken out as a sheet. An insole was obtained by punching from this sheet. Table 1 shows the physical properties of the insole.
[0038]
Comparative Example 2
A reinforcing fiber structure having a three-dimensional structure used in Example 1 is mounted in an aluminum mold having a space of 200 × 400 × 3 mm, and the hydrophilic granular resin used in Example 1 is placed therein. Filled. Next, the mold was heated until its surface temperature reached 140 to 150 ° C., then cooled to room temperature and taken out as a sheet. An insole was obtained by punching from this sheet. Table 1 shows the physical properties of the insole.
[0039]
Example 4
10 parts by weight of chitosan having an average particle diameter of 50 μm as a hygroscopic agent was mixed with 100 parts by weight of the hydrophilic granular resin used in Example 1. A reinforcing fiber structure having a three-dimensional structure used in Example 1 was mounted in an aluminum mold having a space of 200 × 400 × 3 mm, and the mixture was filled therein. Next, the mold was heated until its surface temperature reached 140 to 150 ° C., then cooled to room temperature and taken out as a sheet. An insole was obtained by punching from this sheet. Table 1 shows the physical properties of the insole.
[0040]
[Table 1]

[0041]
【The invention's effect】
Since the insole of the shoe of the present invention has both hygroscopicity and water absorption, it absorbs moisture in the shoe to make it less stuffy and absorbs it in the unlikely event that condensation occurs. Even if you wear shoes over time, you can get good comfort without stuffiness. In addition, since rainwater can be absorbed during rainfall, the feeling of wetness due to rainwater can be prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a preferred example of a reinforcing fiber structure having a three-dimensional structure used in the present invention.
[Explanation of symbols]
1, 2 Ground texture 3 Threads constituting the wall-shaped connecting part

Claims

A hydrophilic resin holding a hygroscopic agent selected from partially pregelatinized starch, chitin, chitosan, activated alumina, and silica gel enters the reinforcing fiber structure as a core and part or all of the surface thereof A shoe insole characterized by having pores continuous from one side to the other side .

The insole of a shoe according to claim 1, wherein the insole has a water-absorbing ability of sucking water up to a height of 10 mm or more from the water surface in one minute after being immersed in water at room temperature.

The insole for shoes according to claim 1, wherein the porosity is 30 to 80%.

The insole for shoes according to claim 1, having a water absorption of 0.5 g or more per gram.

The insole for a shoe according to claim 1, which has a hygroscopicity of 0.01 g or more per gram.

The insole for shoes according to claim 1, wherein a dimensional change rate during drying and water absorption is 0.5% or less.

The insole for shoes according to claim 1, wherein the resin is a hydrophilic polyolefin-based resin.

The insole for shoes according to claim 7, wherein the polyolefin resin is polyethylene.

The insole for shoes according to claim 8, wherein the melt index of polyethylene is 0.001 to 30 g / 10 min.

The insole for shoes according to claim 8, wherein the density of polyethylene is 0.90 to 0.97 g / cc.

Desiccant, shoe insoles according to claim 1, characterized in that it is held 3-70 parts by weight per 100 parts by weight of the resin.

Shoe insoles according to claim 1, wherein the reinforcing fiber structure is characterized by having a three-dimensional structure.

The reinforcing fiber structure having a three-dimensional structure is a fiber structure having a three-dimensional structure composed of a ground structure of two front and back surfaces and a connecting portion of a wall-shaped body that connects the ground structure, and the wall-shaped connecting portion is A plurality of yarns that are formed by a plurality of yarns so that the fiber occupancy is 10 to 80%, and thereby communicate with the fiber structure on the front and back sides. 13. An insole for a shoe according to claim 12, wherein a gap is provided between each wall-like connecting portion.

The insole for shoes according to claim 1, wherein 0.05 to 2 parts by weight of the fungicide and / or the antibacterial agent are held with respect to 100 parts by weight of the resin.

Fungicide, thiabendazole system, and the chitin, one or more members selected from chitosan, claim 14 antimicrobial agents, inorganic antibacterial agents, chitin, characterized in that at least one member selected from chitosan Insole of listed shoes.

Hydrophilic particulate resin, partially α-starch, chitin, chitosan, activated alumina, a mixture of moisture absorbent particulate comprising one or more selected from silica gel, is positioned on the reinforcing fiber structure and its both surfaces The hydrophilic resin that has been molded by leaving a gap between the particles of the hydrophilic granular resin and retained the hygroscopic agent penetrates into the reinforcing fiber structure as the core and covers part or all of the surface thereof. A method for producing an insole for a shoe, comprising a molded body having pores continuous from one side to the other side .

The reinforcing fiber structure has a three-dimensional structure, the average particle diameter of the hydrophilic granular resin is 5 to 2000 μm, and the average particle diameter of the granular hygroscopic agent is 1/3 to 3 times the average particle diameter of the hydrophilic granular resin. , and the a mixture of the two reinforcing fiber structures after being placed on the filling or plane mold shoe of claim 16, characterized in that heating to a temperature above the melting point of the hydrophilic particulate resin Insole manufacturing method.