JP3741180B2 - Thermal adhesive composite fiber, nonwoven fabric and absorbent article using the same - Google Patents
Thermal adhesive composite fiber, nonwoven fabric and absorbent article using the same Download PDFInfo
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- JP3741180B2 JP3741180B2 JP25925197A JP25925197A JP3741180B2 JP 3741180 B2 JP3741180 B2 JP 3741180B2 JP 25925197 A JP25925197 A JP 25925197A JP 25925197 A JP25925197 A JP 25925197A JP 3741180 B2 JP3741180 B2 JP 3741180B2
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
- D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/253—Formation of filaments, threads, or the like with a non-circular cross section; Spinnerette packs therefor
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/28—Formation of filaments, threads, or the like while mixing different spinning solutions or melts during the spinning operation; Spinnerette packs therefor
- D01D5/30—Conjugate filaments; Spinnerette packs therefor
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- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
- D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
- D01F8/06—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyolefin as constituent
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Nonwoven Fabrics (AREA)
- Multicomponent Fibers (AREA)
- Absorbent Articles And Supports Therefor (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
Description
【0001】
【発明の属する技術分野】
本発明は異形断面を有する熱接着性複合繊維及びこれを用いた不織布と吸収性物品に関する。更に詳しくは不織布化工程の熱処理温度が低く、かつ、隠蔽性に優れたポリオレフィン系の異形断面を有する熱接着性複合繊維及びこれを用いた不織布と吸収性物品に関するものである。
【0002】
【従来の技術】
低融点樹脂を鞘成分とし、高融点樹脂を芯成分とする熱接着性複合繊維を用いた不織布は風合い(触感)や不織布強力等の特性が好まれ、紙おむつや生理用品等の衛生材料の表面材として使用されている。このような不織布は、短繊維の場合、通常、熱接着性複合繊維をカード工程や空気流開繊工程によってウエブとした後、加熱処理や加圧処理によって鞘成分を溶融し、繊維交絡点を融着する事によって作製される。
一方、長繊維の代表としては、スパンボンド法によって容易に製造することができる、通常、紡糸口金より吐出した長繊維群をエアーサッカーなどに導入して牽引延伸し、開繊して捕集コンベヤー上に集積してウェブを得た後、加圧処理によって鞘成分を溶融し、繊維交絡点を融着する事によって作成される。
繊維交絡点を融着する方式は、加熱エンボスロール等による熱圧着方式と、サクションバンドドライヤーやサクションドラムドライヤー等による熱風接着方式とに大別する事ができる。それぞれの方式により作製される不織布は、ポイントボンド不織布、スルーエアー不織布と呼ばれ用途に応じて使い分けられる。
【0003】
このような熱接着性(鞘/芯)複合繊維として知られているものには、例えば高密度ポリエチレン/ポリプロピレン系複合繊維(以下、HDPE/PPと略記する)、高密度ポリエチレン/ポリエステル系複合繊維(以下、HDPE/PETと略記する)、プロピレン系共重合体から成る鞘成分にポリプロピレンから成る芯成分が複合された繊維(以下、co−PP/PPと略記する)[特公昭55−26203号公報、特開平2−91217号公報、特開平2−191720号公報]を挙げる事が出来る。
これらの中で、特にco−PP/PPは鞘側を構成する樹脂と芯側を構成する樹脂が共にプロピレン成分を有しているために、鞘成分と芯成分の親和性が極めて高く、HDPE/PPやHDPE/PETに見られるような、鞘側と芯側が剥離する現象が起こり難い。加えて鞘側成分のco−PPは、HDPEに比べて他の樹脂とのヒートシール性に優れることから、co−PP/PPより作製した不織布は、他の樹脂より作製した不織布やフィルムと共に、紙おむつや生理用品に加工した際に丈夫な製品が得られるため、その利用価値が高い。
【0004】
熱接着性複合繊維を用いて不織布を作製する場合、一般に不織布の風合い(触感)は強力と相反する傾向にある。従来、衛生材料用途の不織布は、十分な強力を有し、かつ、生産速度を極力速くする必要があるため、比較的高い温度での熱処理によって生産される事が多かった。しかし、最近の傾向として衛生材料の表面材用途の不織布には、より柔らかい風合い(触感)が求められるようになってきている。このため、co−PP/PPによって作製される不織布についても、柔らかい風合い(触感)を得るために熱処理温度が抑えられる事が多くなってきており、結果として不織布強力が低くなるという難点が生じている。
このため衛生材料用途として、高い強力と柔らかな風合い(触感)の相反する要求を、両方とも満足させる不織布を得る事が可能な、co−PP/PPの熱接着性複合繊維の出現が望まれている。
【0005】
また、表面材としての不織布の要求性能としては、例えば、使い捨ておむつ、生理用ナプキンに使用する場合、乳児の排出物や尿による黄色の着色、女性の経血による赤色の着色は使用感に多大な影響を及ぼすため、これらの着色を見え難くする機能であるカバーリング性が、近年の表面材には必要不可欠とされている。このため、従来の不織布に於けるカバーリング性を向上させる方法としては、構成繊維にTiO2等の顔料を含有して白度をアップする方法があるが、TiO2等の含有量が多すぎると、白度は向上するが繊維の紡糸性、不織布への加工性が悪化し、また、長繊維からステープルへの切断が困難になり、製造コストが増大する。また、隠蔽性を向上させるために坪量を増加させる方法も提案されているが、該方法では、軽量化、コンパクト化、低コスト化に問題がある。
【0006】
【発明が解決しようとする課題】
本発明の目的は低温・高速の熱処理によっても高強度で風合いのソフトな不織布となり、ヒートシール性が高く、かつ、隠蔽性にも優れる不織布の得られる異形断面を有する複合繊維を提供することにある。
【0007】
【課題を解決するための手段】
本発明者らは、上記課題を解決すべく鋭意検討を重ねた結果、以下の構成を採用することにより、所期の目的が達成される見通しを得て、本発明を完成するに至った。
(1)結晶性ポリプロピレンからなる高融点樹脂のA成分と、これより低融点のプロピレン系の共重合体から選ばれた少なくとも1種の低融点樹脂のB成分とから形成された熱接着性複合繊維であって、該複合繊維の断面は高融点樹脂のA成分が中央部から外側に向かってストランドが放射状に伸びる分岐部を形成し、かつ低融点樹脂のB成分がA成分による各ストランドにおいて当該ストランドの長手方向とは交差する方向に当該ストランドを隔てて接続されて突出している2つの突起部を形成している異形構造であることを特徴とする熱接着性複合繊維。
(2)プロピレン系の共重合体成分が、プロピレン85〜99重量%と、エチレン1〜15重量%の二元系共重合体樹脂である(1)項に記載の熱接着性複合繊維。
(3)プロピレン系の共重合体成分が、プロピレン50〜99重量%と、ブテン−1 1〜50重量%の二元系共重合体樹脂である(1)項に記載の熱接着性複合繊維。
(4)プロピレン系の共重合体成分が、プロピレン84〜98重量%、エチレン1〜10重量%、ブテン−1 1〜15重量%の三元系共重合体樹脂である(1)項に記載の熱接着性複合繊維。
(5)(1)〜(4)項のいずれかに記載の熱接着性複合繊維の繊維交差点が熱接合された短繊維不織布。
(6)(1)〜(4)項のいずれかに記載の熱接着性複合繊維の繊維交差点が熱接合された長繊維不織布。
(7)(5)若しくは(6)項に記載の不織布を少なくとも一部に用いた吸収性物品。
【0008】
【発明の実施の形態】
以下、本発明を詳細に説明する。
本発明で複合繊維の高融点樹脂のA成分に使用する結晶性ポリプロピレンとは、ホモポリプロピレン若しくはプロピレンを主成分とし、それと少量のエチレン、ブテンー1、ヘキセンー1、オクテンー1若しくは4ーメチルペンテンー1等のαーオレフィンとの結晶性共重合体であって、MFR(230℃、2.16kg)が2〜150、融点が158℃以上のものが好ましい。このような重合体はチーグラー・ナッタ系触媒を用いるプロピレンの重合方法等の公知の方法によって得られる。
【0009】
本発明で複合繊維の低融点樹脂のB成分に用いるプロピレン系の共重合体とは、プロピレンを主成分とし、それと少量のエチレン、ブテンー1、ヘキセンー1、オクテンー1若しくは4ーメチルペンテンー1等のαーオレフィンとの結晶性共重合体であって、MFR(230℃、2.16kg)が3〜50、融点は120℃〜158℃であり、且つA成分である結晶性ポリプロピレンよりは低いものが用いられる。好ましい具体例としては、プロピレン99〜85重量%とエチレン1〜15重量%とからなるプロピレンを主体とするプロピレン・エチレンの二元共重合体、プロピレン99〜50重量%とブテン−1 1〜50重量%とからなるプロピレンを主体とするプロピレン・ブテンの二元共重合体、あるいはプロピレン84〜98重量%、エチレン1〜10重量%、およびブテン−1 1〜15重量%からなるプロピレン・エチレン・ブテンー1の三元共重合体であり、このような共重合体はチーグラ・ナッタ触媒を用いたオレフィンの共重合方法等の公知の方法により得ることができる。
【0010】
共重合体中のコモノマー(エチレン及びブテン−1)の含量が各々1重量%より少ないと、得られる繊維は熱接着性において不十分なものとなる。また、共重合体の融点が前記の範囲以外の場合、不織布加工速度、不織布強力及び不織布の風合い等のバランスが悪化する。
本発明の熱接着性複合繊維の断面は、高融点樹脂のA成分が中央部から外側に向かって複数のストランドが放射状に伸びる分岐部を形成し、かつ低融点樹脂のB成分がA成分の分岐部と接続して突出する突起部を形成した異形断面構造である。
【0011】
また、熱接着性複合繊維は、それを構成する低融点樹脂成分の一部が製造工程で剥離すると、熱接着された繊維交差点の数が減少し、その結果接着性が低下し好ましくない。特に本発明の複合繊維は特定の異形断面構造を有するため余計に剥離が起こりやすく、このため複合繊維を構成するA、B両樹脂成分の組合わせが重要となる。つまり、構成するA、Bの樹脂成分は互いに親和性が良く、複合繊維に外力が加わっても分割しないことが必要である。本発明の熱接着性複合繊維の断面の一例を図1〜図4に示す。ただし、以下に説明する繊維断面に限定されるものではない。
【0012】
図1に示した熱接着性複合繊維(a1)は高融点樹脂のA成分1が中央部から外側に向かって3本のストランドが放射状に伸びる分岐部を形成し、かつ低温樹脂のB成分2が該分岐部の各ストランドの長手方向先端からその延長線上に伸びて突出する突起部を形成した複合繊維である。
【0013】
図2に示した熱接着性複合繊維(a2)は高融点樹脂のA成分1が中央部から外側に向かって4本のストランドが放射状に伸びる分岐部を形成し、かつ低融点樹脂のB成分2が該分岐部の各ストランドの長手方向先端からその延長線上に伸びて突出する突起部を形成した複合繊維である。
【0014】
図3に示した熱接着性複合繊維(a3)は高融点樹脂のA成分1が中央部から外側に向かって4本のストランドが放射状に伸びる分岐部を形成し、かつ低融点樹脂のB成分2が該分岐部の各ストランドのほぼ先端部近傍に各ストランド毎にストランドの長手方向とは交差する方向(この場合はほぼ直交する方向であるが、交差する角度は任意のものが採用し得る。以下同様である。)にストランドを隔ててほぼ反対方向に接続して突出する2つの突起部とからなる複合繊維である。そしてこの場合、突起部の一方が分岐部のストランドのほぼ先端部近傍の位置に接続しており、もう一方がストランドの先端部よりやや根元寄りの位置に接続している。もちろん両方の突起部がストランドのほぼ同じ位置からストランドを隔ててほぼ反対方向に接続して突出してもよい。
【0015】
図4に示した熱接着性複合繊維(a4)は高融点樹脂のA成分1が中央部から外側に向かって4本のストランドが放射状に伸びる分岐部を形成し、かつ低融点樹脂のB成分2が該分岐部の各ストランドのほぼ先端部近傍に各ストランド毎にストランドの長手方向とは交差する方向(この場合はほぼ直交よりもやや斜めの角度で交差する方向)にストランドを隔ててほぼ反対方向に接続して突出する2つの突起部とからなる複合繊維である。
【0016】
本発明の熱接着性複合繊維は、前述の図1〜図4に例示したように、特殊な異形断面構造を有している。即ち、高融点樹脂のA成分が外側に向かって細いストランド状に突出して分岐状の骨格を形成し、そのA成分の分岐部に低融点樹脂のB成分が一部接合して突起部を形成している。つまり、B成分は極めて細い突起部を有し、前記A成分との一部接合部を除き大部分の表面は露出している。
このような、形態構造の複合繊維が熱処理を受けると、低融点樹脂のB成分は、大部分の露出面から熱伝達を受けるのでB成分が軟化状態から融着に至るまでの熱伝達が極めて容易になる。
特に図5に示すような、通常の鞘芯型やその他の丸断面に比較して低融点樹脂(B成分)の体積に対する露出表面積の割合が著しく大きいので、表面露出部からの熱伝達が速く融着が均一になる。つまり、低温接着性に優れるようになるのである。
この傾向はB成分の突起部が細く、かつ、表面露出度が大きいほど顕著である。
【0017】
本発明でいう低温接着性に優れるということは、図5に示すような通常の丸断面の複合繊維に比較して、本発明の熱接着性繊維は3〜4℃以下の低温での熱接着が十分可能となり、かつ、繊維接合点が融着接合ムラを生じることなく、均一な融着接合が行われることを意味する。
この結果、本発明の熱接着性複合繊維を用いて低温熱処理して得られた不織布は、繊維間の空隙が多く残存し、極めてソフト感を有する。しかも、繊維同士は繊維接点で確実に熱融着されるので不織布は繊維集合体としての結合力を向上させ、高い強力を有するようになる。
これに対し図5の如く、一般の丸断面構造の芯鞘複合繊維では鞘成分全体を十分に溶融させるためには、本発明の複合繊維の場合に比較し、より高温を要する。このような条件下で熱処理が行われると、熱融着による強力は向上するが、反面芯成分も融着温度に近ずくため繊維全体を融着させるようになる。
この結果、必然的に嵩高が失われ、不織布の風合い(ソフトの触感)が損なわれるのである。
【0018】
また、本発明の熱接着性複合繊維は、中央部から外側に向かって放射状に伸びるストランドが分岐した多葉型構造を有するので、入射光が散乱した反射光が視野に見えるようになる。
したがって、本発明の熱接着性複合繊維を不織布、織編物などの布帛としたとき該布帛の下方の色が見えにくい、いわゆる透け防止効果を発揮する。つまり隠蔽性に優れるのである。
【0019】
本発明の熱接着性複合繊維を得るには、短繊維の場合、前述の樹脂A、B成分を上述の繊維断面に代表される紡糸口金プレートを用い、公知の複合紡糸法により紡糸し、延伸し、捲縮を付与する。複合繊維を構成するA、B成分は複合重量比が、A成分/B成分=30/70〜80/20重量%の範囲が好ましい。B成分が20%未満では、得られる繊維の熱接着性が低下し、これを用いた不織布も十分な引張強度および低温接着性を得ることが難しくなる。また、B成分が70%を超すと、繊維の熱接着性は十分であるが、繊維の熱収縮率が高くなり、不織布を得る際の寸法安定性が低下する傾向がある。複合繊維の繊度は0.5〜10.0d/fで、かつ、捲縮数が約3〜60山/25mmのものがカード通過性がよく、好ましい。
【0020】
一方、長繊維の代表としては、前述の樹脂A、B成分を上述の繊維断面に代表される紡糸口金プレートを用い、公知のスパンボンド法により製造することができる。複合繊維を構成するA、B成分は複合重量比が、A成分/B成分=30/70〜80/20重量%の範囲が好ましい。B成分が20%未満では、得られる繊維の熱接着性が低下し、これを用いた不織布も十分な引張強度および低温接着性を得ることが難しくなる。また、B成分が70%を超すと、繊維の熱接着性は十分であるが、繊維の熱収縮率が高くなり、不織布を得る際の寸法安定性が低下する傾向がある。複合繊維の繊度は0.5〜10.0d/fのものが、好ましい。又、必要に応じて、捲縮を与えることもできる。
【0021】
本発明の短繊維不織布は、前述複合繊維をカード機を用いて所望の目付のウェブとし、ニードルパンチ法、サクションドライヤー法、あるいは熱ロール法により不織布とする公知の方法で得ることができる。
一方、長繊維不織布の代表としては、スパンボンド法により不織布とする公知の方法で得ることができる。
【0022】
このような不織布は、紙おむつあるいは生理用ナプキンの表面材等の分野に有用である。この不織布を紙おむつや生理用ナプキン等に使用する場合には、単糸繊度は0.5〜10.0d/f、不織布の目付けは8〜50g/m2のものが好ましく、より好ましくは10〜30g/m2である。単糸が0.5d/f未満では、紡糸時の安定した可紡性が得られ難く、ついては均質なウェブを得ることが困難となり、10.0d/fを超すと不織布の目が粗くなり、これを表面材として使用すれば肌触りに難のあるものとなるので好ましくない。また、目付けが10g/m2未満では薄すぎて十分な不織布強力が得られず、50g/m2を超すと好ましい不織布強力が得られるものの肌触りが悪くコスト高になることから実用的でない。
【0023】
【実施例】
以下実施例により本発明を具体的に説明するが、本発明はこれら実施例のみに限定されるものではない。
尚、以下に述べる実施例中における各種の物性値は以下の方法で測定したものである。
【0024】
・断面形状維持特性:(短繊維)
延伸後の単糸50本を採取、繊維断面を光学顕微鏡写真で撮影し、一視野に当たり異形断面の高融点樹脂のA成分と低融点樹脂のB成分との接続部形状が90%以上維持されていれば優、80%以上維持されていれば良、80%未満であれば不可と評価し、優を○、良を△、不可を×で示した。表1に結果を示す。
【0025】
・断面形状維持特性:(長繊維)
不織布の断面を光学顕微鏡写真で撮影し、熱圧着処理された以外の繊維を観察し、一視野に当り異形断面の高融点樹脂のA成分と低融点樹脂のB成分との接続部形状が90%以上維持されていれば優、80%以上維持されていれば良、80%未満であれば不可と評価し、優を○、良を△、不可を×で示した。表1に結果を示した。
【0026】
・隠蔽性(ウェブの白色度)
ウェブ10gを採取、色差計(SMカラーコンピューター、スガ試験機(株))にて測定、数値が大きい程、隠蔽性が高い。表1に結果を示す。
【0027】
・隠蔽性(不織布の明暗差)
不織布強力において作成した不織布を用い、該不織布の背後に白タイルと黒タイルを置いて色差計にて明度を測定し、明暗差(ΔL)を下記式より算出、明暗差の小さいもの程、隠蔽性が高い。表1に結果を示す。
【0028】
明暗差(ΔL)=L* W−L* B
L* W:白タイルに不織布を重ねた時の明度
L* B:黒タイルに不織布を重ねた時の明度
【0029】
・不織布強力:
不織布の機械の流れ方向(MD)を長さ方向とし、機械の流れ方向に直角な方向(CD)を幅方向として、長さ15cm、幅5cmの試料片を作製し、引張り試験機を用い、つかみ間隔10cm、引張り速度10cm/minで引張り強力を測定した。
【0030】
・不織布風合:
5人のパネラーによる官能試験を行い、全員がソフトであると判断した場合を優、3名以上がソフトであると判断した場合を良、3名以上がソフト感に欠けると判断した場合を不可と評価し、優を○、良を△、不可を×で示した。
【0031】
・ヒートシール性:
上記、不織布強力の測定に用いる不織布から、不織布の機械の流れ方向(MD)を長さ方向とし、機械の流れ方向に直角な方向(CD)を幅方向として、長さ7.5cm、幅2.5cmの試料片を切り出し、同種の不織布同士、又はポリプロピレン繊維(2d/f)からなる目付け約20g/m2の不織布から切り出した長さ7.5cm、幅2.5cmの試料片と、先端部分を長さ1cmだけ重ね合わせ、3kg/cm2の加圧下で3秒間、所定の温度で熱圧着させ、引張り試験機を用い、つかみ間隔10cm、引張り速度10cm/minでヒートシール部の剥離強力を測定する。
【0032】
実施例1(参考例)、比較例1
ブテン−1 5重量%とプロピレン95重量%とからなり、MFRが15である二元共重合体をB成分とし、MFRが10の結晶性ポリプロピレン(ホモポリマー)をA成分として、図1(実施例1)および図5(比較例1)に示した所定の繊維断面となるような紡糸口金を用いて複合紡糸装置により、複合重量比40/60(B成分/A成分)、単糸繊度が4d/fの未延伸糸を得た。その後、95℃の熱ロールにて2.4倍に延伸し、スタッファボックスで機械捲縮を付与し、90℃で乾燥した後、切断処理して2d×38mmの複合繊維を得た。この複合繊維を用いて、温度120℃(実施例1)、124℃(比較例1)に加熱された凸部面積24%のエンボスロールとフラットな金属ロールからなる熱圧着装置を用い、線圧20kg/cm、速度6m/minの条件でカード法ウェブを熱処理し、目付け約20g/m2の不織布とした。さらに、この不織布を大人用おむつの表面材として使用したところ、実施例1については、白度、肌触り(ソフト感)で優れ、かつ、不織布強力、ヒートシール性にも優れていたが、比較例1については、白度が劣り、かつ、不織布強力、ヒートシール性が実施例1より劣り、吸収性物品への適否の差異は明確であった。
【0033】
実施例2〜3
エチレン3重量%、ブテン−1 5重量%、及びプロピレン92重量%からなり、MFRが15である三元共重合体をB成分とし、MFRが10の結晶性ポリプロピレン(ホモポリマー)をA成分として、図3(実施例2)および図4(実施例3)に示した所定の繊維断面となるような紡糸口金を用いて、実施例1と同様な方法にて2d×38mmの複合繊維を得た。この複合繊維を用いて、温度120℃(実施例2、3)に加熱された凸部面積24%のエンボスロールとフラットな金属ロールからなる熱圧着装置を用い、線圧20kg/cm、速度6m/minの条件でカード法ウェブを熱処理し、目付け約20g/m2の不織布とした。
【0034】
比較例2〜3
MIが19の高密度ポリエチレンをB成分、MFRが10の結晶性ポリプロピレン(ホモポリマー)をA成分として、図1(比較例2)および図5(比較例3)に示した所定の繊維断面となるような紡糸口金を用いて、実施例1と同様な方法にて2d×38mmの複合繊維を得た。この複合繊維を用いて、加工温度124℃(比較例2)、128℃(比較例3)とした以外は、実施例1と同条件で不織布を作成した。尚、比較例2は本発明と同様の紡糸口金を使用し、本発明の範囲外の樹脂成分を組み合わせた例である。
【0035】
比較例4
IV値0.65のポリエチレンテフタレートをB成分、IV値0.49のポリエチレンテフタレートをA成分として、図1に示した所定の繊維断面となるような紡糸口金を用いて、実施例1と同様な方法にて2d×38mmの複合繊維を得た。この複合繊維は、延伸後A/B成分が剥離分割し、評価の対象とならなかった。
【0036】
比較例5
MIが19の高密度ポリエチレンをB成分、IV値0.49のポリエチレンテフタレートをA成分として、図2に示した所定の繊維断面となるような紡糸口金を用いて、実施例1と同様な方法にて2d×38mmの複合繊維を得た。この複合繊維は、延伸後A/B成分が剥離分割し、評価の対象とならなかった。
【0037】
実施例4(参考例)、比較例6
ブテン−1 5重量%とプロピレン95重量%とからなり、MFRが15である二元共重合体をB成分とし、MFRが10の結晶性ポリプロピレン(ホモポリマー)をA成分として、図1(実施例4)および図5(比較例6)に示した所定の繊維断面となるような紡糸口金から吐出した複合繊維群をエアーサッカーに導入して牽引延伸し、複合長繊維を得、続いて、エアーサッカーより排出された前記長繊維群を、帯電装置により同電荷を付与せしめ帯電させた後、反射板に衝突させて開繊し、開繊した長繊維群を裏面に吸引装置を設けた無端ネット状コンベヤー上に、長繊維ウェブとして捕集する。捕集した長繊維ウェブは、無端コンベヤーに載せられたまま搬送され、温度120℃に加熱された凸部面積24%のエンボスロールとフラットな金属ロールからなる熱圧着装置を用い、線圧20kg/cm、速度30m/minの条件で熱処理し、目付け約20g/m2の不織布とした。さらに、この不織布を大人用おむつの表面材として使用したところ、実施例4については、白度、肌触り(ソフト感)で優れ、かつ、不織布強力、ヒートシール性にも優れていたが、比較例6については、白度が劣り、かつ、不織布強力、ヒートシール性が実施例4より劣り、吸収性物品への適否の差異は明確であった。
【0038】
《不織布強力、不織布風合、不織布の明暗差およびヒートシール性》
断面形状維持特性において、良(△)以上のサンプルについて評価。短繊維不織布は各繊維をローラーカード機にて20m/minの速度でカーディングし、それぞれ目付け約20g/m2のウエブとした。続いて同一速度で接着面積率24%のエンボスロールを用いて所定温度にて不織布に加工した。それぞれの物性結果を表1に示す。
一方、長繊維不織布は、スパンボンド法にて製造した。目付け約20g/m2のウェブを接着面積率24%のエンボスロールを用いて所定温度にて不織布に加工した。それぞれの物性結果を表1に示す。
【0039】
【表1】
【0040】
【発明の効果】
本発明の異形断面を有する熱接着性複合繊維は、低温で、かつ、短時間の熱処理により不織布強力の大きな不織布が作成できる。また、この熱接着性複合繊維を使用した不織布は、風合いがソフトである。しかも、他のポリオレフィン系不織布に対しても低温でのヒートシール性が良好で、かつ、隠蔽性にも優れている。このような不織布は、紙おむつ及び生理用ナプキンの表面材等の分野に有用である。
【図面の簡単な説明】
【図1】本発明の参考として熱接着性複合繊維の形状を例示した断面図である。
【図2】本発明の参考として熱接着性複合繊維の形状を例示した断面図である。
【図3】本発明の熱接着性複合繊維の形状を例示した断面図である。
【図4】本発明の熱接着性複合繊維の形状を例示した断面図である。
【図5】比較例1、3、6の熱接着性複合繊維の形状を示した断面図である。
【符号の説明】
a1 本発明の参考とする熱接着性複合繊維
a2 本発明の参考とする熱接着性複合繊維
a3 本発明の熱接着性複合繊維
a4 本発明の熱接着性複合繊維
a5 比較例1、3、6の熱接着性複合繊維
1 高融点樹脂(A成分)
2 低融点樹脂(B成分)[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-adhesive conjugate fiber having an irregular cross section, a nonwoven fabric using the same, and an absorbent article. More specifically, the present invention relates to a heat-adhesive conjugate fiber having a low-profile polyolefin cross section having a low heat treatment temperature in the non-woven fabric forming process and excellent in concealability, and a non-woven fabric and an absorbent article using the same.
[0002]
[Prior art]
Nonwoven fabrics using heat-adhesive composite fibers with a low melting point resin as the sheath component and a high melting point resin as the core component are preferred for their characteristics such as texture (tactile feel) and strength of the nonwoven fabric. Used as a material. In the case of such a non-woven fabric, in the case of a short fiber, after the heat-adhesive conjugate fiber is usually made into a web by a card process or an air flow opening process, the sheath component is melted by heat treatment or pressure treatment, and the fiber entanglement point is set. Made by fusing.
On the other hand, as a representative of long fibers, it can be easily manufactured by the spunbond method. Normally, a group of long fibers discharged from a spinneret is introduced into an air soccer, etc., pulled, stretched, opened and collected by a conveyor. After the web is accumulated on top, the sheath component is melted by pressure treatment and the fiber entanglement points are fused.
Methods for fusing fiber entanglement points can be broadly classified into a thermocompression bonding method using a heated embossing roll or the like and a hot air bonding method using a suction band dryer or a suction drum dryer. Nonwoven fabrics produced by the respective methods are referred to as point bond nonwoven fabrics and through-air nonwoven fabrics, and are properly used depending on the application.
[0003]
Examples of such heat-adhesive (sheath / core) composite fibers include high-density polyethylene / polypropylene composite fibers (hereinafter abbreviated as HDPE / PP) and high-density polyethylene / polyester composite fibers. (Hereinafter abbreviated as HDPE / PET), a fiber in which a core component composed of polypropylene is combined with a sheath component composed of a propylene copolymer (hereinafter abbreviated as co-PP / PP) [Japanese Patent Publication No. 55-26203] Gazette, JP-A-2-91217, JP-A-2-191720].
Among these, in particular, co-PP / PP has a very high affinity between the sheath component and the core component because both the resin constituting the sheath side and the resin constituting the core side have a propylene component, and HDPE The phenomenon of peeling between the sheath side and the core side as seen in / PP and HDPE / PET hardly occurs. In addition, the sheath-side component co-PP is superior in heat-sealability with other resins compared to HDPE, so the non-woven fabric made from co-PP / PP, together with non-woven fabrics and films made from other resins, The durable value is obtained when processed into disposable diapers and sanitary products, so its utility value is high.
[0004]
When producing a nonwoven fabric using heat-adhesive conjugate fibers, the texture (tactile feel) of the nonwoven fabric generally tends to conflict with strength. Conventionally, non-woven fabrics for hygiene materials have sufficient strength and are required to be produced as fast as possible, so that they are often produced by heat treatment at a relatively high temperature. However, as a recent trend, a softer texture (tactile sensation) has been demanded for non-woven fabrics used for surface materials of sanitary materials. For this reason, the non-woven fabric produced by co-PP / PP is also often suppressed in the heat treatment temperature in order to obtain a soft texture (tactile sensation), resulting in a problem that the strength of the nonwoven fabric is reduced. Yes.
For this reason, the emergence of co-PP / PP heat-adhesive composite fibers that can obtain nonwoven fabrics that satisfy both the requirements of high strength and soft texture (tactile sensation) are desired. ing.
[0005]
As the required performance of the nonwoven fabric as the surface material, for example, when used for disposable diapers and sanitary napkins, yellow coloring due to infant discharge and urine, and red coloring due to women's menstrual blood greatly affect the feeling of use. Therefore, the covering property, which is a function of making these colorings difficult to see, is indispensable for recent surface materials. For this reason, as a method for improving the covering property in the conventional nonwoven fabric, the constituent fiber is TiO 2.2There is a method to increase the whiteness by containing a pigment such as TiO2If the content is too large, the whiteness is improved, but the fiber spinnability and processability into a nonwoven fabric are deteriorated, and it becomes difficult to cut long fibers into staples, resulting in an increase in production cost. In addition, a method for increasing the basis weight has been proposed in order to improve concealment, but this method has problems in terms of weight reduction, compactness, and cost reduction.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a composite fiber having a modified cross-section from which a non-woven fabric having a high strength and a soft texture even by low-temperature and high-speed heat treatment, having high heat sealability and excellent concealment properties can be obtained. is there.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained the prospect that the intended purpose will be achieved by adopting the following configuration, and have completed the present invention.
(1) A heat-adhesive composite formed from an A component of a high melting point resin made of crystalline polypropylene and a B component of at least one low melting point resin selected from propylene copolymers having a lower melting point The cross-section of the composite fiber is such that the A component of the high melting point resin forms a branched portion in which the strands extend radially from the center to the outside, and the B component of the low melting point resinTwo protrusions protruding from each strand of the A component connected to the strand in a direction crossing the longitudinal direction of the strand with the strand being separatedFormingingA heat-adhesive conjugate fiber characterized by an irregular structure.
(2) The heat-adhesive conjugate fiber according to item (1), wherein the propylene-based copolymer component is a binary copolymer resin of 85 to 99% by weight of propylene and 1 to 15% by weight of ethylene.
(3) The heat-adhesive conjugate fiber according to item (1), wherein the propylene-based copolymer component is a binary copolymer resin of 50 to 99% by weight of propylene and 1 to 50% by weight of butene-1. .
(4) The propylene copolymer component is a ternary copolymer resin of 84 to 98% by weight of propylene, 1 to 10% by weight of ethylene, and 1 to 15% by weight of butene-1; Thermal adhesive composite fiber.
(5) A short fiber nonwoven fabric in which fiber intersections of the heat-adhesive conjugate fiber according to any one of (1) to (4) are thermally bonded.
(6) A long-fiber nonwoven fabric in which fiber intersections of the heat-adhesive conjugate fiber according to any one of (1) to (4) are thermally bonded.
(7) An absorbent article using at least a portion of the nonwoven fabric described in (5) or (6).
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
In the present invention, the crystalline polypropylene used for the component A of the high melting point resin of the composite fiber is mainly composed of homopolypropylene or propylene and a small amount of ethylene, butene-1, hexene-1, octene-1 or 4-methylpentene-1. A crystalline copolymer with an α-olefin such as MFR (230 ° C., 2.16 kg) of 2 to 150 and a melting point of 158 ° C. or higher is preferable. Such a polymer can be obtained by a known method such as a propylene polymerization method using a Ziegler-Natta catalyst.
[0009]
The propylene-based copolymer used for the B component of the low melting point resin of the composite fiber in the present invention is mainly composed of propylene and a small amount of ethylene, butene-1, hexene-1, octene-1, 4-methylpentene-1, etc. A crystalline copolymer of α-olefin with MFR (230 ° C., 2.16 kg) of 3 to 50, melting point of 120 ° C. to 158 ° C. and lower than crystalline polypropylene as component A Is used. Preferable specific examples include a propylene / ethylene binary copolymer mainly composed of 99 to 85% by weight of propylene and 1 to 15% by weight of ethylene, 99 to 50% by weight of propylene and 1 to 50 of butene. Propylene-butene binary copolymer composed mainly of propylene consisting of 5% by weight, or propylene / ethylene-propylene consisting of 84 to 98% by weight of propylene, 1 to 10% by weight of ethylene, and 1 to 15% by weight of butene-11 This is a terpolymer of butene-1, and such a copolymer can be obtained by a known method such as an olefin copolymerization method using a Ziegler-Natta catalyst.
[0010]
If the content of comonomer (ethylene and butene-1) in the copolymer is less than 1% by weight, the resulting fiber will have insufficient thermal adhesion. Moreover, when the melting point of the copolymer is outside the above range, the balance such as the nonwoven fabric processing speed, the strength of the nonwoven fabric, and the texture of the nonwoven fabric is deteriorated.
The cross section of the heat-adhesive conjugate fiber of the present invention is such that the A component of the high melting point resin forms a branched portion in which a plurality of strands extend radially from the center to the outside, and the B component of the low melting point resin is the A component. This is a modified cross-sectional structure in which a protruding portion that is connected to the branch portion and protrudes is formed.
[0011]
Further, when a part of the low melting point resin component constituting the heat-adhesive conjugate fiber is peeled off in the production process, the number of fiber-crossing points that are heat-adhered is decreased, and as a result, the adhesiveness is lowered. In particular, since the conjugate fiber of the present invention has a specific irregular cross-sectional structure, it is more likely to peel off. For this reason, the combination of both A and B resin components constituting the conjugate fiber is important. That is, the constituent resin components A and B have good affinity to each other, and it is necessary not to be divided even when an external force is applied to the composite fiber. An example of a cross section of the heat-adhesive conjugate fiber of the present invention is shown in FIGS. However, it is not limited to the fiber cross section described below.
[0012]
In the heat-adhesive conjugate fiber (a1) shown in FIG. 1, the
[0013]
In the heat-adhesive conjugate fiber (a2) shown in FIG. 2, the
[0014]
In the heat-adhesive conjugate fiber (a3) shown in FIG. 3, the
[0015]
In the heat-adhesive conjugate fiber (a4) shown in FIG. 4, the
[0016]
The heat-adhesive conjugate fiber of the present invention has a special modified cross-sectional structure as illustrated in FIGS. That is, the A component of the high melting point resin protrudes in the form of a thin strand toward the outside to form a branched skeleton, and the B component of the low melting point resin partially joins the branched portion of the A component to form a protrusion. is doing. That is, the B component has a very thin protrusion, and most of the surface is exposed except for a part of the junction with the A component.
When such a composite fiber having a morphological structure is subjected to heat treatment, the B component of the low melting point resin receives heat transfer from most of the exposed surface, so that the heat transfer from the softened state to the fusion is extremely high. It becomes easy.
In particular, the ratio of the exposed surface area to the volume of the low melting point resin (component B) is remarkably large as compared with a normal sheath core type or other round cross section as shown in FIG. Fusion is uniform. That is, it becomes excellent in low temperature adhesiveness.
This tendency becomes more conspicuous as the B component protrusion is thinner and the surface exposure is larger.
[0017]
The excellent low-temperature adhesiveness referred to in the present invention means that the heat-adhesive fiber of the present invention has a thermal bond at a low temperature of 3 to 4 [deg.] C. or lower, as compared with a composite fiber having an ordinary round cross section as shown in FIG. Can be sufficiently achieved, and the fusion bonding can be performed without causing uneven fusion bonding at the fiber bonding point.
As a result, the nonwoven fabric obtained by low-temperature heat treatment using the thermoadhesive conjugate fiber of the present invention has a lot of voids between the fibers and has a very soft feeling. In addition, since the fibers are reliably heat-sealed at the fiber contacts, the nonwoven fabric improves the bonding strength as a fiber assembly and has high strength.
On the other hand, as shown in FIG. 5, a core-sheath composite fiber having a general round cross-sectional structure requires a higher temperature than the composite fiber of the present invention in order to sufficiently melt the entire sheath component. When heat treatment is performed under such conditions, the strength by thermal fusion is improved, but the core component is also close to the fusion temperature, so that the entire fiber is fused.
As a result, the bulk is inevitably lost, and the texture (soft touch) of the nonwoven fabric is impaired.
[0018]
Moreover, since the thermoadhesive conjugate fiber of the present invention has a multileaf structure in which strands extending radially outward from the center portion are branched, reflected light in which incident light is scattered can be seen in the field of view.
Therefore, when the heat-adhesive conjugate fiber of the present invention is used as a fabric such as a nonwoven fabric or a woven or knitted fabric, a so-called see-through preventing effect is exhibited in which the color below the fabric is difficult to see. That is, it is excellent in concealment.
[0019]
In order to obtain the heat-adhesive conjugate fiber of the present invention, in the case of short fibers, the above-mentioned resins A and B are spun by a known conjugate spinning method using a spinneret plate represented by the above-mentioned fiber cross section, and drawn. And crimp. The A and B components constituting the composite fiber preferably have a composite weight ratio in the range of A component / B component = 30/70 to 80/20% by weight. When the component B is less than 20%, the thermal adhesiveness of the resulting fiber is lowered, and it is difficult for a nonwoven fabric using the fiber to obtain sufficient tensile strength and low-temperature adhesiveness. On the other hand, if the component B exceeds 70%, the thermal adhesiveness of the fibers is sufficient, but the thermal shrinkage of the fibers is increased, and the dimensional stability when obtaining a nonwoven fabric tends to be lowered. It is preferable that the fineness of the composite fiber is 0.5 to 10.0 d / f and the number of crimps is about 3 to 60/25 mm because of good card passage.
[0020]
On the other hand, as a representative of long fibers, the above-mentioned resins A and B can be produced by a known spunbond method using a spinneret plate represented by the above-mentioned fiber cross section. The A and B components constituting the composite fiber preferably have a composite weight ratio in the range of A component / B component = 30/70 to 80/20% by weight. When the component B is less than 20%, the thermal adhesiveness of the resulting fiber is lowered, and it is difficult for a nonwoven fabric using the fiber to obtain sufficient tensile strength and low-temperature adhesiveness. On the other hand, if the component B exceeds 70%, the thermal adhesiveness of the fibers is sufficient, but the thermal shrinkage of the fibers is increased, and the dimensional stability when obtaining a nonwoven fabric tends to be lowered. The fineness of the composite fiber is preferably 0.5 to 10.0 d / f. Further, crimping can be given as necessary.
[0021]
The short fiber nonwoven fabric of the present invention can be obtained by a known method in which the above-mentioned composite fiber is made into a web having a desired basis weight using a card machine and is made into a nonwoven fabric by a needle punch method, a suction dryer method, or a hot roll method.
On the other hand, as a representative of the long fiber nonwoven fabric, it can be obtained by a known method for forming a nonwoven fabric by a spunbond method.
[0022]
Such a nonwoven fabric is useful in the field of a surface material of a paper diaper or a sanitary napkin. When this nonwoven fabric is used for paper diapers, sanitary napkins, etc., the single yarn fineness is 0.5 to 10.0 d / f, and the basis weight of the nonwoven fabric is 8 to 50 g / m.2Are preferred, more preferably 10-30 g / m2It is. If the single yarn is less than 0.5 d / f, it is difficult to obtain a stable spinnability at the time of spinning, and it is difficult to obtain a homogeneous web, and if it exceeds 10.0 d / f, the nonwoven fabric becomes rough, If this is used as a surface material, it becomes difficult to touch, which is not preferable. In addition, the basis weight is 10 g / m2If it is less than 50 g / m, it is too thin and sufficient nonwoven fabric strength cannot be obtained.2However, it is impractical because the nonwoven fabric has a preferable non-woven fabric strength but is uncomfortable and expensive.
[0023]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
In addition, the various physical-property values in the Example described below are measured with the following method.
[0024]
-Cross-sectional shape maintenance characteristics: (short fiber)
50 stretched single yarns were sampled, the fiber cross section was photographed with an optical micrograph, and the shape of the connecting portion between the A component of the high melting point resin and the B component of the low melting point resin having a deformed cross section per field of view was maintained at 90% or more. Excellent, if it was maintained at 80% or more, good, and if it was less than 80%, it was evaluated as bad. Table 1 shows the results.
[0025]
-Cross-sectional shape maintenance characteristics: (long fiber)
The cross section of the non-woven fabric is photographed with an optical micrograph, and fibers other than those subjected to thermocompression treatment are observed. % Is maintained as good, 80% or more is maintained as good, and less than 80% is evaluated as unsatisfactory. Table 1 shows the results.
[0026]
・ Concealment (web whiteness)
10 g of web was sampled and measured with a color difference meter (SM color computer, Suga Test Instruments Co., Ltd.). The greater the numerical value, the higher the concealability. Table 1 shows the results.
[0027]
・ Concealment (non-woven fabric contrast)
Using a non-woven fabric created with strong non-woven fabric, place a white tile and black tile behind the non-woven fabric, measure the brightness with a color difference meter, calculate the light / dark difference (ΔL) from the following formula, High nature. Table 1 shows the results.
[0028]
Light / dark difference (ΔL) = L* W-L* B
L* W: Lightness when non-woven fabric is layered on white tile
L* B: Brightness when non-woven fabric is stacked on black tile
[0029]
・ Nonwoven fabric strong:
A non-woven fabric machine flow direction (MD) is the length direction, a direction perpendicular to the machine flow direction (CD) is the width direction, a sample piece having a length of 15 cm and a width of 5 cm is prepared using a tensile tester, Tensile strength was measured at a gripping interval of 10 cm and a pulling speed of 10 cm / min.
[0030]
・ Nonwoven fabric texture:
Perform sensory test with 5 panelists and judge that everyone is soft. If 3 or more are judged soft, accept if 3 or more lack softness. It was evaluated as “Excellent”, “Excellent”, “Good”, “No”, and “No”.
[0031]
・ Heat sealability:
From the nonwoven fabric used for measuring the strength of the nonwoven fabric, the machine direction of the nonwoven fabric (MD) is the length direction, the direction perpendicular to the machine flow direction (CD) is the width direction, and the length is 7.5 cm and the width 2 A sample piece of .5 cm is cut out, and the basis weight is approximately 20 g / m made of the same kind of non-woven fabric or polypropylene fibers (2d / f).2A sample piece 7.5 cm long and 2.5 cm wide cut out from a non-woven fabric is overlapped with a tip portion of 1 cm in length, and 3 kg / cm2And press-bonding at a predetermined temperature for 3 seconds, and using a tensile tester, the peel strength of the heat seal part is measured at a gripping interval of 10 cm and a pulling speed of 10 cm / min.
[0032]
Example 1(Reference example)Comparative Example 1
A binary copolymer consisting of 5% by weight of butene-1 and 95% by weight of propylene and having an MFR of 15 is used as the B component, and a crystalline polypropylene (homopolymer) having an MFR of 10 is used as the A component. Example 1) and a composite spinning apparatus using a spinneret having a predetermined fiber cross section shown in FIG. 5 (Comparative Example 1), a composite weight ratio of 40/60 (component B / component A), and single yarn fineness An undrawn yarn of 4 d / f was obtained. Thereafter, the film was stretched 2.4 times with a 95 ° C. hot roll, mechanically crimped with a stuffer box, dried at 90 ° C., and then cut to obtain a 2d × 38 mm composite fiber. Using this composite fiber, a linear pressure was applied using a thermocompression bonding device comprising an embossing roll having a convex area of 24% and a flat metal roll heated to 120 ° C. (Example 1) and 124 ° C. (Comparative Example 1). The curd method web was heat-treated under the conditions of 20 kg / cm and speed of 6 m / min, and the basis weight was about 20 g / m.2The nonwoven fabric was made. Furthermore, when this nonwoven fabric was used as a surface material for diapers for adults, Example 1 was excellent in whiteness and touch (soft feeling), strong in nonwoven fabric, and excellent in heat sealability. About 1, the whiteness was inferior, and the nonwoven fabric strength and heat sealability were inferior to Example 1, and the difference of the suitability to an absorbent article was clear.
[0033]
Examples 2-3
A ternary copolymer consisting of 3% by weight of ethylene, 5% by weight of butene-1 and 92% by weight of propylene and having an MFR of 15 is used as component B, and a crystalline polypropylene (homopolymer) having an MFR of 10 is used as component A. Using the spinneret having the predetermined fiber cross section shown in FIG. 3 (Example 2) and FIG. 4 (Example 3), a composite fiber of 2d × 38 mm was obtained in the same manner as in Example 1. It was. Using this composite fiber, a thermocompression bonding device comprising an embossing roll having a convex area of 24% and a flat metal roll heated to a temperature of 120 ° C. (Examples 2 and 3), a linear pressure of 20 kg / cm, a speed of 6 m The card method web is heat-treated under the conditions of / min and the basis weight is about 20 g / m.2The nonwoven fabric was made.
[0034]
Comparative Examples 2-3
A high-density polyethylene having an MI of 19 and a component B shown in FIG. 1 (Comparative Example 2) and FIG. 5 (Comparative Example 3) with a crystalline polypropylene (homopolymer) having an MFR of 10 as an A component Using such a spinneret, a composite fiber of 2d × 38 mm was obtained in the same manner as in Example 1. Using this conjugate fiber, a nonwoven fabric was prepared under the same conditions as in Example 1 except that the processing temperature was 124 ° C. (Comparative Example 2) and 128 ° C. (Comparative Example 3). In Comparative Example 2, a spinneret similar to that of the present invention was used, and resin components outside the scope of the present invention were combined.
[0035]
Comparative Example 4
Using a spinneret having a predetermined fiber cross section shown in FIG. 1 with polyethylene terephthalate having an IV value of 0.65 as component B and polyethylene terephthalate having an IV value of 0.49 as component A, Example 1 and A 2d × 38 mm composite fiber was obtained in the same manner. This composite fiber was not subject to evaluation because the A / B component was separated after being stretched.
[0036]
Comparative Example 5
A high-density polyethylene having an MI of 19 is used as a B component, and a polyethylene terephthalate having an IV value of 0.49 is used as an A component. The composite fiber of 2dx38mm was obtained by the method. This composite fiber was not subject to evaluation because the A / B component was separated after being stretched.
[0037]
Example 4(Reference example)Comparative Example 6
A binary copolymer consisting of 5% by weight of butene-1 and 95% by weight of propylene and having an MFR of 15 is used as the B component, and a crystalline polypropylene (homopolymer) having an MFR of 10 is used as the A component. The composite fiber group discharged from the spinneret as shown in Example 4) and FIG. 5 (Comparative Example 6) was introduced into an air soccer ball and pulled to obtain a composite long fiber, The long fiber group discharged from the air soccer is charged with the same charge applied by a charging device, then opened by colliding with a reflector, and the opened long fiber group is provided with a suction device on the back surface. Collected as a long fiber web on a net conveyor. The collected long fiber web is transported while being placed on an endless conveyor and is heated to 120 ° C., using a thermocompression bonding device composed of an embossing roll having a convex area of 24% and a flat metal roll, and a linear pressure of 20 kg / heat treatment under conditions of cm and speed of 30 m / min, with a weight per unit of about 20 g / m2The nonwoven fabric was made. Furthermore, when this nonwoven fabric was used as a surface material for diapers for adults, Example 4 was excellent in whiteness and touch (soft feeling) and strong in nonwoven fabric and heat sealability. Regarding No. 6, the whiteness was inferior, the nonwoven fabric was strong and the heat sealability was inferior to that of Example 4, and the difference in suitability for absorbent articles was clear.
[0038]
<< Strong nonwoven fabric, nonwoven fabric texture, contrast and heat sealability of nonwoven fabric >>
Evaluate samples with good (Δ) or better in cross-sectional shape maintenance characteristics. Short fiber nonwoven fabric is carded with a roller card machine at a speed of 20 m / min.2The web. Subsequently, it was processed into a nonwoven fabric at a predetermined temperature using an embossing roll having a bonding area ratio of 24% at the same speed. The respective physical property results are shown in Table 1.
On the other hand, the long fiber nonwoven fabric was manufactured by the spunbond method. Approximately 20g / m2The web was processed into a non-woven fabric at a predetermined temperature using an embossing roll having an adhesion area ratio of 24%. The respective physical property results are shown in Table 1.
[0039]
[Table 1]
[0040]
【The invention's effect】
The thermoadhesive conjugate fiber having a modified cross section of the present invention can produce a nonwoven fabric having a strong nonwoven fabric by heat treatment at a low temperature for a short time. In addition, the nonwoven fabric using this heat-adhesive conjugate fiber has a soft texture. In addition, the heat sealability at low temperatures is good with respect to other polyolefin-based nonwoven fabrics, and the hiding properties are also excellent. Such a nonwoven fabric is useful in fields such as paper diapers and surface materials for sanitary napkins.
[Brief description of the drawings]
FIG. 1 of the present inventionAs referenceIt is sectional drawing which illustrated the shape of the heat bondable conjugate fiber.
FIG. 2 of the present inventionAs referenceIt is sectional drawing which illustrated the shape of the heat bondable conjugate fiber.
FIG. 3 is a cross-sectional view illustrating the shape of a thermoadhesive conjugate fiber of the present invention.
FIG. 4 is a cross-sectional view illustrating the shape of a thermoadhesive conjugate fiber of the present invention.
FIG. 5 is a cross-sectional view showing the shape of heat-adhesive conjugate fibers of Comparative Examples 1, 3, and 6.
[Explanation of symbols]
a1 of the present inventionFor referenceThermal adhesive composite fiber
a2 of the present inventionFor referenceThermal adhesive composite fiber
a3 Thermal adhesive composite fiber of the present invention
a4 Thermal adhesive composite fiber of the present invention
a5 Thermal adhesive composite fibers of Comparative Examples 1, 3, and 6
1 High melting point resin (component A)
2 Low melting point resin (component B)
Claims (7)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25925197A JP3741180B2 (en) | 1997-01-20 | 1997-09-08 | Thermal adhesive composite fiber, nonwoven fabric and absorbent article using the same |
EP98100922A EP0854213B1 (en) | 1997-01-20 | 1998-01-20 | Heat-fusible composite fiber, and non-woven fabrics and absorbent products produced from the same |
DE69805664T DE69805664T2 (en) | 1997-01-20 | 1998-01-20 | Hot-melt adhesive composite fibers and nonwovens and absorbent products made therefrom |
CN98105650A CN1195040A (en) | 1997-01-20 | 1998-01-20 | Heat-fusible composite fiber, and non-woven fabrics and absorbent products produced from same |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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JP9-21023 | 1997-01-20 | ||
JP2102397 | 1997-01-20 | ||
JP25925197A JP3741180B2 (en) | 1997-01-20 | 1997-09-08 | Thermal adhesive composite fiber, nonwoven fabric and absorbent article using the same |
Publications (2)
Publication Number | Publication Date |
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JPH10259522A JPH10259522A (en) | 1998-09-29 |
JP3741180B2 true JP3741180B2 (en) | 2006-02-01 |
Family
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JP25925197A Expired - Fee Related JP3741180B2 (en) | 1997-01-20 | 1997-09-08 | Thermal adhesive composite fiber, nonwoven fabric and absorbent article using the same |
Country Status (4)
Country | Link |
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EP (1) | EP0854213B1 (en) |
JP (1) | JP3741180B2 (en) |
CN (1) | CN1195040A (en) |
DE (1) | DE69805664T2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11323663A (en) * | 1998-05-19 | 1999-11-26 | Chisso Corp | Thermally bondable conjugate fiber, nonwoven fabric and absorbing article using the same |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
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US6074590A (en) * | 1997-07-28 | 2000-06-13 | Fina Technology, Inc. | Process of making a bicomponent fiber |
CN1078645C (en) * | 1999-01-22 | 2002-01-30 | 四川省对外经济贸易总公司 | Special synthetic fiber paper and its production |
FR2790489B1 (en) * | 1999-03-01 | 2001-04-20 | Freudenberg Carl Fa | TABLECLOTH NOT WOVEN IN THERMOLIA FILAMENTS OR FIBERS |
JP2002542403A (en) * | 1999-04-15 | 2002-12-10 | バセル テクノロジー カンパニー ビー.ブイ. | Heat-bondable polyolefin fiber consisting of random copolymer of propylene |
JP5854458B2 (en) * | 2011-09-30 | 2016-02-09 | ユニチカ株式会社 | Method for producing polyester long fiber nonwoven fabric |
CN102534863A (en) * | 2011-12-29 | 2012-07-04 | 江西国桥实业有限公司 | Double-component non-woven spinning and production method thereof |
JP6099330B2 (en) * | 2012-08-02 | 2017-03-22 | 日本バイリーン株式会社 | filter |
US20140272223A1 (en) * | 2013-03-15 | 2014-09-18 | The Procter & Gamble Company | Packages for articles of commerce |
WO2015052460A1 (en) * | 2013-10-09 | 2015-04-16 | Ucl Business Plc | Chromatography medium |
CN203795029U (en) * | 2013-12-04 | 2014-08-27 | 太仓荣文合成纤维有限公司 | Gray elastic fiber and spinneret plate for manufacturing gray elastic fibers |
EP3127594B1 (en) | 2014-03-31 | 2018-11-28 | Unitika Ltd. | Air filter material |
CA2955900C (en) | 2014-04-17 | 2022-10-18 | Basf Se | Combination of novel nitrification inhibitors and biopesticides as well as combination of (thio)phosphoric acid triamides and biopesticides |
CN112281228A (en) * | 2020-09-10 | 2021-01-29 | 深圳市华远新材料有限公司 | Cross-shaped sheath-core structure polylactic acid tow and preparation method thereof |
CN116590804B (en) * | 2023-07-17 | 2024-03-22 | 江苏新视界先进功能纤维创新中心有限公司 | Profiled fiber with multistage wicking structure and application of profiled fiber to geotextile |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
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JPS6285025A (en) * | 1985-10-04 | 1987-04-18 | Nippon Ester Co Ltd | Hot-melt polyester conjugate yarn |
JPS63295712A (en) * | 1987-02-16 | 1988-12-02 | Mitsubishi Rayon Co Ltd | Modified cross-section heat fusible fiber |
JPH055261A (en) * | 1991-06-27 | 1993-01-14 | Oji Paper Co Ltd | Nonwoven fabric consisting of conjugate type filament |
JP3261728B2 (en) * | 1992-02-18 | 2002-03-04 | チッソ株式会社 | Thermal adhesive fiber sheet |
JP3109628B2 (en) * | 1992-09-25 | 2000-11-20 | チッソ株式会社 | Manufacturing method of composite fiber |
US5707735A (en) * | 1996-03-18 | 1998-01-13 | Midkiff; David Grant | Multilobal conjugate fibers and fabrics |
-
1997
- 1997-09-08 JP JP25925197A patent/JP3741180B2/en not_active Expired - Fee Related
-
1998
- 1998-01-20 DE DE69805664T patent/DE69805664T2/en not_active Expired - Lifetime
- 1998-01-20 EP EP98100922A patent/EP0854213B1/en not_active Expired - Lifetime
- 1998-01-20 CN CN98105650A patent/CN1195040A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11323663A (en) * | 1998-05-19 | 1999-11-26 | Chisso Corp | Thermally bondable conjugate fiber, nonwoven fabric and absorbing article using the same |
Also Published As
Publication number | Publication date |
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CN1195040A (en) | 1998-10-07 |
DE69805664D1 (en) | 2002-07-11 |
EP0854213B1 (en) | 2002-06-05 |
EP0854213A1 (en) | 1998-07-22 |
DE69805664T2 (en) | 2003-02-06 |
JPH10259522A (en) | 1998-09-29 |
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