JP4442013B2

JP4442013B2 - Composite nonwoven fabric and fiber product using the same

Info

Publication number: JP4442013B2
Application number: JP2000301936A
Authority: JP
Inventors: 勲板倉; 満小島
Original assignee: Chisso Polypro Fiber Co Ltd; Chisso Corp
Current assignee: JNC Corp; JNC Fibers Corp
Priority date: 2000-10-02
Filing date: 2000-10-02
Publication date: 2010-03-31
Anticipated expiration: 2020-10-02
Also published as: JP2002105831A

Description

【０００１】
【発明の属する技術分野】
本発明は、非常にソフトな風合いを有し、更に不織繊維集合体層間が剥離せず耐毛羽立ち性を兼備した複合化不織布及びこれを用いた繊維製品に関するものである。
【０００２】
【従来の技術】
熱可塑性繊維を原料とし、熱圧着加工により得られた不織布は、生産性が良好でコスト的に優れており、また、柔らかな風合いと高い不織布特性（高不織布強力）が好まれ、衛材用途に用いられている。しかしながら、最近の傾向として衛材の表面材には、より柔らかい風合い（触感）が要求されている。また、紙オムツのトップシートやバックシートに不織布を使用した場合に問題となる不織布の耐毛羽立ち性に関しても、不織布強力及び風合いと共に重要な不織布製品の品質項目であることから、これらを向上させることが要求されている。
【０００３】
耐毛羽立ち性、不織布強力及び風合いをすべて満足する不織布は、単層の不織布では得られにくいため、複数種の不織布を積層した不織布による検討がなされている。例えば、特開平５−３３２５７号公報には、ポリエチレンテレフタレートを芯成分とし、高密度ポリエチレンを鞘成分とする鞘芯型複合長繊維で構成された２枚の不織布層の間にポリエチレンテレフタレート長繊維で構成された不織布層が存在している３層構造を持ち、不織布全体が部分的に熱圧着されている積層不織布が提案されている。
【０００４】
この方法では中層のポリエチレンテレフタレート長繊維が上下層の繊維より高い融点の樹脂成分からなるため、部分的に熱圧着されても中層は繊維同士の接着が少なく、長繊維は自由度が比較的高い状態となる。このとき中層の繊維が接着していないために、不織布の柔軟性は向上するものの、不織布強力は不十分となる。そのため、十分な不織布強力を得るために上下層の繊維をより高温に処理しなければならず、熱圧着ロールへの融着が起こる等の問題が生じていた。また、積層間の接着が不足しているため、不織布を擦り合わせた際、積層間の剥離が起こり、その結果、耐毛羽立ち性に問題が残っていた。
【０００５】
この欠点を補うため、特開平８−４１７６８号公報には、長繊維群Ａのみからなる部分と長繊維群Ａよりも、２０℃以上融点の高い重合体成分からなる長繊維群Ｂのみからなる層間に、長繊維群Ａと長繊維群Ｂとが互いに混在した部分を持つ長繊維群Ｃを積層して、熱圧着加工を行った積層不織布が提案されている。
【０００６】
この方法では、長繊維群Ｃに長繊維群Ａおよび長繊維群Ｂの繊維が混在しているため、該長繊維Ｃと長繊維群Ａおよび長繊維群Ｂとの積層間の剥離を抑制する効果が得られる。しかし、この方法では長繊維群Ａおよび長繊維群Ｂの融点差が異なるため、加工温度を高融点側若しくは高融点側と低融点側の各々別の加工温度に設定する必要がある。しかし、高融点側に加工温度を合わせた場合、低融点側に掛かる熱量が過剰となり、長繊維群を構成する熱可塑性樹脂が、加工装置に融着する問題が生じていた。次に高融点側と低融点側の各々別の加工温度に設定した場合、中層である長繊維群Ｃに掛かる熱量が不足気味となり、積層間の剥離が起こる問題が生じていた。また、長繊維群Ｃは融点差の異なる長繊維群Ａおよび長繊維群Ｂが混在している構成のため、該長繊維群Ｃは自己の接着および積層間の接着に十分な融着部分が少なく、その結果、繊維の自由度が高くなり、不織布強力不足や耐毛羽立ち性に問題があった。
【０００７】
更に、特許第３０４３０９９号公報には、複合長繊維Ａのみから構成される層１と複合長繊維Ｂのみから構成される層４との間にある層２，層３が、複合長繊維群Ａと複合長繊維群Ｂの単位体積あたりの繊維重量比を連続的に変化した層（以下、混繊部分という）である不織布が開示されている。この方法では、混繊部分の地合が不均一であり、混繊部分の複合長繊維Ａと複合長繊維Ｂの割合が偏るといった混繊ムラのため、層間の接着性が悪くなる。その結果、積層間の剥離が問題となっていた。
【０００８】
耐毛羽立ち性の向上に最も効果が大きいのは不織布表面の接着面積率を大きくすることであるが、接着面積率を大きくすると不織布の風合いが損なわれてしまう。また、加工温度を高くすると熱圧着ロールへの融着や巻き付きが起こる。更に圧着ポイントのエッジ部分で繊維が受けるダメージが大きくなり、繊維が切断しやすく耐毛羽立ちが悪化する。一方、加工温度を低く抑える方法は、不織布内部の熱接着が不十分となるために不織布強力不足や層間剥離の原因となる。つまり不織布の風合いを重視すると耐毛羽立ち性の悪化や層間剥離といった問題が生じる。一方、耐毛羽立ち性を重視すると不織布の風合いおよび熱圧着ロールへの融着や巻き付きによる操業性の悪化といった問題が生じていた。
このように不織布の風合いと不織布積層間の接着強力及び耐毛羽立ち性を兼備させる様々な不織布の製造方法が提案されているが、十分に満足する性能の不織布は得られていない。
【０００９】
【発明が解決しようとする課題】
本発明の目的は、不織布の風合いと不織布積層間の接着強力及び耐毛羽立ち性を有する複合化不織布およびこれを用いた繊維製品を提供することにある。
【００１０】
【課題を解決するための手段】
本発明者らは、上記課題を解決するために鋭意検討を重ねた。その結果、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、この知見に基づいて、本発明を完成するに至った。
（１）熱可塑性樹脂（Ａ）を原料とする不織繊維集合体（Ｉ）と熱可塑性樹脂（Ｂ）を原料とする不織繊維集合体（II）とで構成される両不織布の積層間に、前記熱可塑性樹脂（Ａ）及び前記熱可塑性樹脂（Ｂ）の両成分が繊維表面に露出した複合繊維で構成された不織繊維集合体（III）を配した複合化不織布であり、該不織繊維集合体（III）は、前記不織繊維集合体（Ｉ）及び不織繊維集合体（II）と熱接合していることを特徴とする複合化不織布。
（２）不織繊維集合体（Ｉ）の原料である熱可塑性樹脂（Ａ）もしくは不織繊維集合体（II）の原料である熱可塑性樹脂（Ｂ）が、それぞれ低密度ポリエチレン，直鎖状低密度ポリエチレン，高密度ポリエチレン，ポリプロピレン，プロピレン系二元共重合体，及びプロピレン系三元共重合体からなるオレフィン系樹脂、ポリエステル、及び共重合ポリエステルの群から選ばれた少なくとも１種の異種の熱可塑性樹脂もしくは融点が異なる同種の熱可塑性樹脂である前記（１）項記載の複合化不織布。
（３）不織繊維集合体（Ｉ）が熱可塑性樹脂（Ａ）と該熱可塑性樹脂（Ａ）よりも１０℃以上高い融点を有する熱可塑性樹脂（Ａ'）から構成される複合繊維である前記（１）項または前記（２）項記載の複合化不織布。
（４）不織繊維集合体（II）が熱可塑性樹脂（Ｂ）と該熱可塑性樹脂（Ｂ）よりも１０℃以上高い融点を有する熱可塑性樹脂（Ｂ'）から構成される複合繊維である前記（１）項または前記（２）項記載の複合化不織布。
（５）不織繊維集合体（Ｉ）、（II）、及び（III）が、長繊維不織布である前記（１）〜（４）項のいずれか１項記載の複合化不織布。
（６）前記（１）〜（５）項のいずれか１項記載の複合化不織布と、前記複合化不織布以外の他の不織布、フィルム、パルプシート、編物、及び織物から選ばれた少なくとも１種を積層した積層複合化不織布。
（７）前記（１）〜（５）項のいずれか１項記載の複合化不織布または前記（６）項記載の積層複合化不織布を用いた吸収性物品。
（８）前記（１）〜（５）項のいずれか１項記載の複合化不織布または前記（６）項記載の積層複合化不織布を用いたワイパー。
【００１１】
【発明の実施の形態】
以下、本発明を詳細に説明する。
本発明の複合化不織布は、熱可塑性樹脂（Ａ）を原料とする不織繊維集合体（Ｉ）と熱可塑性樹脂（Ｂ）を原料とする不織繊維集合体（II）とで構成される両不織布の積層間に、前記熱可塑性樹脂（Ａ）及び前記熱可塑性樹脂（Ｂ）の両成分が繊維表面に露出した複合繊維で構成された不織繊維集合体（III）を配した複合化不織布であり、不織繊維集合体（III）は、前記不織繊維集合体（Ｉ）及び前記不織繊維集合体（II）と熱接合によって接着されている。つまり不織繊維集合体（Ｉ）側のウエブは熱可塑性樹脂（Ａ）の軟化点で熱接着が行われ、不織繊維集合体（II）側のウエブは熱可塑性樹脂（Ｂ）の軟化点で熱接着が行われている。つまり不織繊維集合体（Ｉ）側は不織繊維集合体（III）の熱可塑性樹脂（Ａ）と熱接着をし、不織繊維集合体（II）側は不織繊維集合体（III）の熱可塑性樹脂（Ｂ）と熱接着をする。従って、表面部の不織繊維集合体（Ｉ）と不織繊維集合体（II）が十分に不織繊維集合体（III）と接着しているため、十分な不織布強力が得られ、繊維の自由度も抑制されることから両不織布積層間の剥離防止にもなり、且つ熱による過剰なダメージを受けていないので不織布の風合いは良好となる。
【００１２】
ところで、不織繊維集合体（Ｉ）、不織繊維集合体（II）と不織繊維集合体（III）を一体化する方法としては熱風加熱加工方式と熱圧着加工方式のいずれもが可能であるが、エンボス装置に代表される熱圧着加工方式がより好ましく用いられる。
熱圧着加工は、熱と圧による加工方法であるため、熱風による加工方法である熱風加熱加工と比べ、溶着する低融点樹脂の融点より低い温度で接着加工でき、生産性がよいことから、コスト面で非常に優れている。
【００１３】
熱圧着加工（エンボスロール加工）を用いて不織繊維集合体を一体化する場合、耐毛羽立ち性はエンボス面積率（凸部）と加工温度による依存度が大きい。そこで、本発明の熱可塑性の複合化不織布は、中層部分が上下層と同一の樹脂成分を有するため、不織布表面にダメージを与えない加工温度において、その内部全体が十分に接着性に寄与して繊維の自由度を制御する。このため同じエンボス面積率の場合、従来の不織布に比較して風合いおよび耐毛羽立ち性に優れ、十分な不織布強力も得られる。また溶融樹脂によるロール捲き付きを抑制することができ、安定生産（操業性）が得られる。従来の技術では接着面積率を下げた場合は不織布表面の繊維自由度が増し、一方、加工温度を下げた場合は不織布内部の繊維自由度が増すため、双方とも耐毛羽立ち性が低下する傾向であった。
【００１４】
本発明の複合化不織布における不織繊維集合体（III）の繊維の複合形態は、熱可塑性樹脂（Ａ）と熱可塑性樹脂（Ｂ）とが共に繊維表面に露出し、且つ断面積比率が同じである並列型が適しており、断面形状としては円形以外にも放射型や放射中空型など種々の異形断面形状であっても良い。また、発明の効果を妨げない範囲で熱可塑性樹脂（Ａ）と熱可塑性樹脂（Ｂ）以外の熱可塑性樹脂が繊維内部に含まれている構造であっても良い。更に熱可塑性樹脂（Ａ）と熱可塑性樹脂（Ｂ）の体積比率Ｖ_A／Ｖ_Bは、不織繊維集合体（Ｉ）と不織繊維集合体（II）、それぞれとの接着強力を均等に出すために７／３〜３／７が好ましく、４／６〜６／４がより好ましい。
【００１５】
本発明で熱可塑性樹脂（Ａ）および熱可塑性樹脂（Ｂ）の組合せは特に制限はないが、熱可塑性樹脂（Ａ）／熱可塑性樹脂（Ｂ）の組合せとしては、高密度ポリエチレン／ポリプロピレン、低密度ポリエチレン／ポリプロピレン、直鎖状低密度ポリエチレン／ポリプロピレン、プロピレンと他のαオレフィンとの二元共重合体または三元共重合体／プロピレンと他のαオレフィンとの二元共重合体または三元共重合体、直鎖状低密度ポリエチレン／高密度ポリエチレン、低密度ポリエチレン／高密度ポリエチレン、低密度ポリエチレン／直鎖状低密度ポリエチレン、直鎖状低密度ポリエチレン／プロピレンと他のαオレフィンとの二元共重合体または三元共重合体、低密度ポリエチレン／プロピレンと他のαオレフィンとの二元共重合体または三元共重合体、高密度ポリエチレン／プロピレンと他のαオレフィンとの二元共重合体または三元共重合体、プロピレンと他のαオレフィンとの二元共重合体または三元共重合体／ポリプロピレン、直鎖状低密度ポリエチレン／ポリエステル、低密度ポリエチレン／ポリエステル、高密度ポリエチレン／ポリエステル、共重合ポリエステル／ポリエステル、ナイロン６／ナイロン６６等が例示できる。これらの中ではプロピレン系樹脂／プロピレン系樹脂、ポリエチレン系樹脂／ポリエチレン系樹脂、ポリエステル系樹脂／ポリエステル系樹脂、ポリアミド系樹脂／ポリアミド系樹脂等の融点差を有する同一成分系樹脂の組合せが、層間の接着効果が大きく、より好ましく用いられる。
【００１６】
本発明で熱可塑性樹脂（Ａ）および熱可塑性樹脂（Ｂ）に用いられるポリエチレンとしては、通常工業的に利用されているポリエチレン樹脂が好ましく用いられ、例えば密度が０．９１０〜０．９２５ｇ／ｃｍ³の低密度ポリエチレン、密度が０．９２６〜０．９４０ｇ／ｃｍ³の直鎖状低密度ポリエチレン、密度が０．９４１〜０．９８０ｇ／ｃｍ³の高密度ポリエチレンを挙げることができる。特にメルトフローレート（ＭＩ：ＪＩＳＫ７２１０表１中の条件４に準拠して測定した値）が２〜１００ｇ／１０分の範囲のポリエチレンが好ましい。
【００１７】
本発明において熱可塑性樹脂（Ａ）および熱可塑性樹脂（Ｂ）に用いられるポリプロピレンとしては、ホモポリプロピレン、プロピレン系二元共重合体、プロピレン系三元共重合体が好ましく、特に、メルトフローレート（ＭＦＲ：ＪＩＳＫ７２１０表１中の条件１４に準拠して測定した値）が２〜１５０ｇ／１０分、融点が１２０〜１６５℃のポリプロピレンが好ましい。
【００１８】
本発明において熱可塑性樹脂（Ａ）および熱可塑性樹脂（Ｂ）に用いられる前記プロピレン系二元共重合体およびプロピレン系三元共重合体としては、プロピレンを主成分とし、それと少量のエチレン、１−ブテン、１−ヘキセン、１−オクテン、若しくは４、４'−ジメチル１−ぺンテン等のαオレフィンとの結晶性共重合体が好ましく、特に、ＭＦＲが２〜１５０ｇ／１０分、融点が１２０〜１５８℃の範囲のプロピレン系二元共重合体およびプロピレン系三元共重合体が好適に用いられる。具体例としては、プロピレン単位を９９〜８５重量％とエチレン単位を１〜１５重量％含む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、プロピレン単位を９９〜５０重量％，１−ブテン単位を１〜５０重量％含むプロピレンを主体とするプロピレン／１−ブテンの二元共重合体、あるいはプロピレン単位を８４〜９８重量％，エチレン単位を１〜１０重量％，１−ブテン単位を１〜１５重量％含むプロピレン／エチレン／１−ブテンの三元共重合体が挙げられる。
【００１９】
本発明で用いられる熱可塑性樹脂には、本発明の効果を妨げない範囲内でさらに酸化防止剤、光安定剤、紫外線吸収剤、中和剤、造核剤、エポキシ安定剤、滑剤、抗菌剤、難燃剤、帯電防止剤、顔料、可塑剤、親水剤等を必要に応じて適宜添加しても良い。また本発明の複合化不織布には必要に応じ、界面活性剤等の付着処理を行っても良い。
【００２０】
本発明の複合化不織布に用いられる不織繊維集合体（Ｉ）の繊維構成は熱可塑性樹脂（Ａ）の単一繊維でもよく、熱可塑性樹脂（Ａ）を鞘成分とし、該（Ａ）よりも１０℃以上高い融点を有する熱可塑性樹脂（Ａ'）を芯成分とした複合繊維でも良く、より好ましくは該（Ａ）よりも３０℃以上高い融点を有する熱可塑性樹脂（Ａ'）を芯成分とした複合繊維が望ましい。
【００２１】
更に本発明の複合化不織布に用いられる不織繊維集合体（II）の繊維構成は熱可塑性樹脂（Ｂ）の単一繊維でもよく、熱可塑性樹脂（Ｂ）を鞘成分とし、該（Ｂ）よりも１０℃以上高い融点を有する熱可塑性樹脂（Ｂ'）を芯成分とした複合繊維でも良く、より好ましくは該（Ｂ）よりも３０℃以上高い融点を有する熱可塑性樹脂（Ｂ'）を芯成分とした複合繊維が望ましい。
【００２２】
本発明の複合化不織布に用いられる不織繊維集合体（Ｉ）、不織繊維集合体（II）、及び不織繊維集合体（III）を構成する繊維には特に制限はなく、種々の短繊維あるいは長繊維を用いることができる。例えば、繊維として複合繊維からなる短繊維を用いる場合、その製造方法としては、並列型、鞘芯型、偏心鞘芯型、多分割型等の繊維断面とな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を行い、得られた未延伸糸を延伸機により延伸後、さらに得られた延伸糸をクリンパーにより捲縮を付与し、カッターにより所望のカット長に切断し、短繊維とする製造方法が例示できる。なお、中でも複合形式としては、寸法安定性に優れる同心型が好ましい。また、延伸後に捲縮を付与せずに、ストレートカットし、チョップとすることもできる。
また、紡糸機より溶融紡出されたポリマー流を高温の高圧空気流により牽引、細化し、移動する捕集面上に捕集、堆積させてウェブとする、公知のメルトブロー方式による製造方法も例示できる。なお、メルトブロー方式で得られた繊維も、短繊維の代表として挙げられる。
一方、繊維として複合繊維からなる長繊維を用いる場合、その製造方法としては、並列型、鞘芯型、偏心鞘芯型、多分割型等の繊維断面とな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方法が例示できる。なお、繊維としては、複合繊維だけでなく、単一繊維も用いることができる。
【００２３】
本発明の複合化不織布を構成する繊維の繊度や目付は、特に限定されるものではないが風合いや柔軟性の点で、それぞれ０．０１〜１１デシテックス（以下、ｄｔｅｘという）、５〜４０ｇ／ｍ²のものが好ましく、より好ましくは０．０３〜７ｄｔｅｘ、８〜３０ｇ／ｍ²である。目付が５ｇ／ｍ²を下回ると十分な不織布強力が得られず、逆に４０ｇ／ｍ²を大幅に上回る十分な不織布強力は得られるものの、肌触りが悪くなり衛生材料などの表面材には適さない。
また、複合繊維を用いる場合の複合重量比（鞘成分の重量％／芯成分の重量％）は、２０／８０〜７０／３０の範囲が好ましく、より好ましくは４０／６０〜６０／４０である。鞘成分が２０重量％を下回ると得られる繊維の熱接着性が不十分となり、逆に鞘成分が７０％を超すと、熱処理時に複合繊維に収縮が起こり、得られる布帛の寸法安定性が低下する傾向がある。
【００２４】
本発明の複合化不織布の構成成分である不織繊維集合体（Ｉ）、不織繊維集合体（II）及び不織繊維集合体（III）の積層目付の比は、得られる複合化不織布の物性に大きく関連している。不織繊維集合体（Ｉ）の目付／不織繊維集合体（III）の目付の比が、０．２〜５となることが好ましい。特に好ましくは０．３〜４である。この目付比が５を大きく超えると熱処理した際、不織布の接着性が低下し、積層間の剥離や耐毛羽立ち性に難がある。また０．２未満では耐毛羽立ち性は向上するものの、不織布の風合いが損なわれる恐れがある。また不織繊維集合体（II）の目付／不織繊維集合体（III）の目付の比も０．２〜５となることが好ましい。特に好ましくは０．３〜４である。この目付比が５を大きく超えると熱処理した際、不織布の接着性が低下し、積層間の剥離や耐毛羽立ち性に難がある。また０．２未満では耐毛羽立ち性は向上するものの、不織布の風合いが損なわれる恐れがある。更に該不織繊維集合体（Ｉ）と該不織繊維集合体（II）の目付比は同一比に限定されず、任意に選択できる。
【００２５】
本発明の不織繊維集合体（Ｉ）、不織繊維集合体（II）、及び不織繊維集合体（III）を熱圧着加工で一体化する場合、特にその製造装置に制限はないが、通常は一対のエンボスロールとフラットロールからなる熱圧着装置が使用されている。このとき、圧着温度は不織布を構成する樹脂の融点によって決まるが、不織繊維集合体（Ｉ）と不織繊維集合体（II）とに融点差が十分にあれば、積層間の剥離を防ぐために、両者のうち高融点側のロール温度を高く設定しておくことが望ましい。また、エンボス面積率は不織布総面積に対し、５〜３０％の範囲が好ましく、より好ましくは９〜２２％である。融着区域の面積が５％未満では不織布積層間の層間剥離が懸念され、３０％を越えると風合いを損なう恐れがある。
【００２６】
本発明の複合化不織布において、その効果を妨げない範囲で、他の不織布、フィルム、パルプシート、編物、織物を積層させ、積層複合化不織布とすることができる。また、他の不織布、フィルム、パルプシート、編物、織物を積層させる複合化不織布は、それぞれを単独で本発明の複合化不織布を積層させても良く、また、複数組み合わせて積層させても良い。その素材には制約は無く、種々のものが利用できるが、基となる不織布と接着可能な素材を含むことが好ましく、さらに接着可能な素材であることがより好ましい。
【００２７】
本発明の複合化不織布および積層複合化不織布は、吸収性物品の材料として利用することが可能である。特に乳幼児用や大人用の使い捨てオムツ、ナプキン、吸汗パット、皮脂除去用シート材、お手拭き等の衛生材料として、特に好ましく利用できる。さらに、本発明の複合化不織布および積層複合化不織布はワイパーとしても好ましく利用できる。一例を挙げると、家庭用使い捨て雑巾、窓拭き、床拭き材、畳拭き材等がある。この他、飛行機や旅客車両の使い捨てシートカバー、便座カバー、衣服の保温剤、型どり基材等としても使用できる。
【００２８】
【実施例】
以下、本発明を実施例及び比較例によって詳細に説明するが、本発明はこれらによってなんら限定されるものではない。なお実施例、比較例における物性の測定方法と官能評価は以下の通りである。
【００２９】
（１）熱可塑性樹脂の融点（繊維成形後の融点）
ＭＰ（℃）：ＪＩＳＫ７１２２に準拠して測定。
【００３０】
（２）不織布風合い
１０人のパネラーによる官能試験を行い、８名以上がソフトであると判断した場合を優、６〜７名がソフトであると判断した場合を良、５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】
（３）不織布強力（ＭＤ方向）
不織布の機械の流れ方向をＭＤ方向とし、機械の流れ方向に直角な方向をＣＤ方向とし、試験片を不織布から次のサイズで切り出した。不織布からＭＤ方向１５ｃｍ×ＣＤ方向２．５ｃｍの短冊形状に５枚切り出し、不織布強力測定用のサンプルとした。この試験片を島津製作所（株）製オートグラフＡＧＳ５００Ｄを用いて、つかみ間隔１０ｃｍ、引張速度１０ｃｍ／分の条件で強力を測定し、最大強力（Ｎ／２．５ｃｍ）を求めた。測定は、１枚につき一回行い、計５回の測定を実施し、その平均値を算出した。平均値を、そのサンプルの不織布強力の値とした。
【００３２】
（４）耐毛羽立ち性評価
以下に、得られた不織布の耐毛羽立ち性（毛羽の立ち難さ）を評価するための方法を記載する。なお、評価方法はＪＩＳＬ０８４９−１９７４に準ずる。
▲１▼試験片としては、評価対象の不織布をＭＤ方向４ｃｍ×ＣＤ方向２０ｃｍの大きさに切断し、これを４枚用意する。さらに評価対象の不織布をＭＤ方向２０ｃｍ×ＣＤ方向４ｃｍの大きさに切断し、これを４枚用意する。
▲２▼不織布サンプルの長手方向中央部に、幅３．５ｃｍ×長さ２０ｃｍの両面テープを貼り付ける。この際、ＭＤ・ＣＤ各々、エンボスロール処理面側とフラットロール処理面側の不織布サンプルを２枚作製する。
▲３▼摩擦試験機（スガ試験機社製）の試料台に不織布サンプルを貼り付け、摩擦子にカナキン３号布（４ｃｍ×５ｃｍ）を装着する。
▲４▼摩擦子を不織布サンプルの上に置き、往復１５０回の摩擦試験を行う。このときの不織布表面の擦れ具合（毛玉の発生や毛羽立ち具合）を、下記判定基準（官能指標）に基づいて官能的に評価する。
判定基準（官能指標）
◎：毛羽立ち・毛玉ともに観察されない。
○：毛羽立ちが若干観察される。
△：毛羽立ちが多く・毛玉が観察される。
×：毛羽立ち多く・複数の毛玉が観察される。
【００３３】
実施例１
熱可塑性樹脂（Ａ）として、融点が１６０℃、ＭＦＲが３６ｇ／１０分である結晶性ポリプロピレンを用いて、公知のスパンボンド法により紡糸を行ない、不織繊維集合体（Ｉ）を製造した。具体的には、この結晶性ポリプロピレンを紡糸機に投入し、熱溶融させ、紡糸口金から単一長繊維群として吐出させた。次に、これをエアーサッカーに通し排出させることで、前記長繊維を牽引延伸し、２ｄｔｅｘの単一長繊維とした。さらに排出された前記長繊維群を帯電装置で帯電させた後、反射板に衝突させることで開繊させ、裏面に吸引装置を設けた無端ネット状コンベヤー上に捕集し、単一長繊維ウェブを得た。このウェブを不織繊維集合体（Ｉ）として用いた。
同様に、熱可塑性樹脂（Ｂ）として、融点が１３９℃、ＭＦＲが３８ｇ／１０分であり、エチレン単位を３重量％，１−ブテン単位を２重量％，プロピレン単位を９５重量％を含むプロピレン系三元共重合体を用いて、同様のスパンボンド法により紡糸を行い、同様に、２ｄｔｅｘの単一長繊維からなる単一長繊維ウェブを得た。このウェブを不織繊維集合体（II）として用いた。
更に、熱可塑性樹脂（Ａ）として、融点が１６０℃、ＭＦＲが３６ｇ／１０分である結晶性ポリプロピレンを用い、熱可塑性樹脂（Ｂ）として、融点が１３９℃、ＭＦＲが３８ｇ／１０分であり、エチレン単位を３重量％，１−ブテン単位を２重量％，プロピレン単位を９５重量％を含むプロピレン系三元共重合体を用いて、公知のスパンボンド法により紡糸を行ない、不織繊維集合体（III）を製造した。具体的には、上記２種の熱可塑性樹脂を紡糸機に投入し、熱溶融させ、並列型複合紡糸口金から並列型複合繊維群として吐出させた。次に、これをエアーサッカーに通し排出させることで、前記複合繊維を牽引延伸し、２ｄｔｅｘの並列型複合長繊維とした。さらに排出された前記並列型複合長繊維群を帯電装置で帯電させた後、反射板に衝突させて長繊維群を開繊させ、裏面に吸引装置を設けた無端ネット状コンベヤー上に捕集することで、複合長繊維ウェブとした。これを不織繊維集合体（III）として用いた。
不織繊維集合体（II）、不織繊維集合体（III）そして不織繊維集合体（Ｉ）をそれぞれ下層、中層そして上層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１２５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は表１に見られるように、風合い、不織布強力、耐毛羽立ち性共に優れるものであった。
【００３４】
実施例２
熱可塑性樹脂（Ａ）として、融点が２６０℃、固有粘度が０．６５であるポリエチレンテレフタレートを用い、公知の溶融紡糸法により紡糸を行ない、不織繊維集合体（Ｉ）を製造した。まず、このポリエチレンテレフタレートを紡糸機に投入し、熱溶融させ、紡糸口金から単一繊維群として吐出させ、単糸繊度６ｄｔｅｘの未延伸糸とした。続いてこの未延伸糸を熱ロールにて２．４倍に延伸し、機械捲縮を付与し、さらに切断処理をして２．５ｄｔｅｘ×３８ｍｍの単一繊維とした。得られた単一繊維をローラーカード機にてカーディングを行ってウェブとした。これを不織繊維集合体（Ｉ）として用いた。
同様に、熱可塑性樹脂（Ｂ）として、融点が１３０℃、ＭＩが３５ｇ／１０分である高密度ポリエチレンを用いて、公知の溶融紡糸法により紡糸を行ない、不織繊維集合体（II）を製造した。まず、該高密度ポリエチレンを紡糸機に投入し、熱溶融させ、紡糸口金から単一繊維群として吐出させ、単糸繊度８ｄｔｅｘの未延伸糸とした。続いて、この未延伸糸を熱ロールにて２．０倍に延伸し、機械捲縮を付与し、さらに切断処理をして４．０ｄｔｅｘ×３８ｍｍの単一繊維とした。得られた単一繊維をローラーカード機にてカーディングを行いウェブをとした。これを不織繊維集合体（II）として用いた。
更に、熱可塑性樹脂（Ａ）として、融点が２６０℃、固有粘度が０．６５であるポリエチレンテレフタレートを用い、熱可塑性樹脂（Ｂ）として、融点が１３０℃、ＭＩが３５ｇ／１０分である高密度ポリエチレンを用いて、通常の溶融紡糸法により紡糸を行ない、不織繊維集合体（III）を製造した。まず、上記２種の熱可塑性樹脂を別々のホッパーから紡糸機に投入し、熱溶融させ、並列型複合紡糸口金から複合繊維群として吐出させ、単糸繊度６ｄｔｅｘの未延伸糸とした。続いて、この未延伸糸を熱ロールにて２．０倍に延伸し、機械捲縮を付与し、さらに切断処理をして３．０ｄｔｅｘ×３８ｍｍの並列型複合繊維とし、得られた複合繊維をローラーカード機にてカーディングを行ってウェブを得、これを不織繊維集合体（III）として用いた。
不織繊維集合体（II）、不織繊維集合体（III）そして不織繊維集合体（Ｉ）をそれぞれ下層、中層そして上層に位置するようにな堆積させ、線圧４０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝２００／１１５℃のエンボス熱圧着装置により熱圧着処理し、不織布を得た。得られた複合化不織布は表１に見られるように、風合い、不織布強力、耐毛羽立ち性共に優れるものであった。
【００３５】
実施例３
不織繊維集合体（III）については、実施例１と同様な熱可塑性樹脂（Ａ）、熱可塑性樹脂（Ｂ）を用いて、公知のメルトブロー法により紡糸を行なうことで製造した。まず、２種の熱可塑性樹脂を別々のホッパーから紡糸機に投入し、熱溶融させ、並列型紡糸口金から複合繊維群として吐出させた。次に、これを高圧熱風によりブローすることで細繊化させ、無端ネット状コンベヤー上に複合短繊維ウェブとして捕集した。これを不織繊維集合体（III）として用いた。
実施例１で採取した不織繊維集合体（Ｉ）、不織繊維集合体（II）と前記不織繊維集合体（III）をそれぞれ上層、下層そして中層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１２５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は表１に見られるように、風合い、不織布強力、耐毛羽立ち性共に非常に優れるものであった。
【００３６】
実施例４
不織繊維集合体（Ｉ）については、実施例１と同様な熱可塑性樹脂（Ａ）を用いて、公知のスパンボンド法により紡糸を行なうことで単一長繊維ウェブとして製造した。
不織繊維集合体（II）については、融点が１２５℃、ＭＩが２０ｇ／１０分である直鎖状低密度ポリエチレンを熱可塑性樹脂（Ｂ）として用い、融点が１５９℃、ＭＦＲが４０ｇ／１０分である結晶性ポリプロピレンを熱可塑性樹脂（Ｂ'）として用いて、公知のスパンボンド法により紡糸を行うことで製造した。まず、両者を別々のホッパーから紡糸機に投入し、熱溶融させ、鞘芯型紡糸口金から複合繊維群として吐出させた。次に、これをエアーサッカーに通し、排出させることで、牽引延伸し、２ｄｔｅｘの鞘芯型複合長繊維とした。さらに排出された前記長繊維群を帯電装置で帯電させた後、反射板に衝突させることで開繊させ、裏面に吸引装置を設けた無端ネット状コンベヤー上に捕集し、複合長繊維ウェブを得た。これを不織繊維集合体（II）として用いた。
更に、熱可塑性樹脂（Ａ）として、実施例１と同様な熱可塑性樹脂を、熱可塑性樹脂（Ｂ）として、融点が１２５℃、ＭＩが２０ｇ／１０分である直鎖状低密度ポリエチレンを用いて、公知のスパンボンド法により実施例１と同様な方法で２ｄｔｅｘ複合長繊維ウェブを得て、これを不織繊維集合体（III）として用いた。
不織繊維集合体（II）、不織繊維集合体（III）そして不織繊維集合体（Ｉ）をそれぞれ下層、中層そして上層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１０５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は表１に見られるように、耐毛羽立ち性に非常に優れ、また風合い、不織布強力も共に優れるものであった。
【００３７】
実施例５
熱可塑性樹脂（Ａ）として、融点が１３０℃、ＭＩが３０ｇ／１０分である高密度ポリエチレンを用い、熱可塑性樹脂（Ａ'）として、融点が１５９℃、ＭＦＲが４０ｇ／１０分である結晶性ポリプロピレンを用いて、公知のスパンボンド法により紡糸を行ない、不織繊維集合体（Ｉ）を製造した。具体的には、熱可塑性樹脂（Ａ）を鞘成分側、熱可塑性樹脂（Ａ'）芯成分側として、両者を別々のホッパーから紡糸機に投入し、熱溶融させ、鞘芯型紡糸口金から複合繊維群として吐出させた。次に、これをエアーサッカーに通し、排出させることで、牽引延伸し、２ｄｔｅｘの鞘芯型複合長繊維とした。さらに排出された前記長繊維群を帯電装置で帯電させた後、反射板に衝突させることで開繊させ、裏面に吸引装置を設けた無端ネット状コンベヤー上に捕集し、複合長繊維ウェブを得た。これを不織繊維集合体（Ｉ）として用いた。
同様に、熱可塑性樹脂（Ｂ）として、融点が１３９℃、ＭＦＲが３８ｇ／１０分であり、エチレン単位を３重量％，１−ブテン単位を２重量％，プロピレン単位を９５重量％を含むプロピレン系三元共重合体を用い、熱可塑性樹脂（Ｂ'）として、融点が１５９℃、ＭＦＲが４０ｇ／１０分である結晶性ポリプロピレンを用いて、公知のスパンボンド法により紡糸を行ない、２ｄｔｅｘの鞘芯型複合長繊維からなるウェブを製造し、これを不織繊維集合体（II）とした。
更に、熱可塑性樹脂（Ａ）として、融点が１３０℃、ＭＩが３０ｇ／１０分である高密度ポリエチレンを用い、熱可塑性樹脂（Ｂ）として、融点が１３９℃、ＭＦＲが３８ｇ／１０分であり、エチレン単位を３重量％，１−ブテン単位を２重量％，プロピレン単位を９５重量％を含むプロピレン系三元共重合体を用いて、公知のスパンボンド法により紡糸を行ない、２ｄｔｅｘの並列型複合長繊維からなるウェブを製造し、これを不織繊維集合体（III）として用いた。
不織繊維集合体（II）、不織繊維集合体（III）そして不織繊維集合体（Ｉ）をそれぞれ下層、中層そして上層に位置するように堆積させ、線圧４０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１２０／１３０℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は表１に見られるように、風合いに非常に優れ、また不織布強力、耐毛羽立ち性も共に優れるものであった。
【００３８】
実施例６
実施例３で得られた本発明の複合化不織布を子供用オムツのバックシートとして使用したところ、耐毛羽立ち性に問題なく、優れた触感を示した。
【００３９】
実施例７
実施例１で得られた本発明の複合化不織布を窓吹き用ワイパーとして使用したところ、非常に良好なゴミ吸着性を示した。
【００４０】
比較例１
実施例１で採取した不織繊維集合体（Ｉ）、不織繊維集合体（II）を用い、それぞれ上層、下層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１２５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布の風合いは、表１に見られるように、非常に劣る傾向であった。
【００４１】
比較例２
不織繊維集合体（III）として、実施例２の不織繊維集合体（Ｉ）と同様な方法で採取した２．５ｄｔｅｘ×３８ｍｍのポリエチレンテレフタレートの単一繊維と、実施例２の不織繊維集合体（II）と同様な方法で採取した４．０ｄｔｅｘ×３８ｍｍの高密度ポリエチレンの単一繊維を、重量比５０％／５０％に混繊しローラーカード機にてカーディングを行うことで得られたウェブを用いた。
不織繊維集合体（Ｉ）として、実施例２の不織繊維集合体（Ｉ）と同様な方法で採取した２．５ｄｔｅｘ×３８ｍｍのポリエチレンテレフタレートの単一繊維を、ローラーカード機にてカーディングを行うことで得られたウェブを用い、不織繊維集合体（II）として、４．０ｄｔｅｘ×３８ｍｍの高密度ポリエチレン単一繊維を、ローラーカード機にてカーディングを行うことで得られたウェブを用いた。
不織繊維集合体（Ｉ）と不織繊維集合体（II）との間に不織繊維集合体（III）を積層して、線圧４０Ｎ／ｍｍ、圧着面積率１５％、エンボスロール／フラットロールの熱処理温度＝２００／１１５℃のエンボス熱圧着装置により熱圧着処理して、複合化不織布を得た。
得られた複合化不織布は、実施例２と比べて全体的に接着不足であり耐毛羽立ち性が非常に悪く、不織布強力も低い値であった。
【００４２】
比較例３
不織繊維集合体（III）については、融点が１６０℃、ＭＦＲが３６ｇ／１０分である結晶性ポリプロピレンを用いて、公知のメルトブロー法により紡糸を行なうことで製造した。まず、結晶性ポリプロピレンを紡糸機に投入し、熱溶融させ、紡糸口金より単一繊維群として吐出させ、さらにこれを高圧熱風によりブローすることで細繊化させ、無端ネット状コンベヤー上に単一短繊維ウェブとして捕集した。これを不織繊維集合体（III）として用いた。
実施例３で採取した不織繊維集合体（Ｉ）、不織繊維集合体（II）と前記不織繊維集合体（III）をそれぞれ上層、下層、中層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１２５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は、実施例３と比べて風合いに劣る傾向であった。
【００４３】
比較例４
不織繊維集合体（III）については、融点が１６０℃、ＭＦＲが３６ｇ／１０分である結晶性ポリプロピレンを用いて、公知のスパンボンド法により紡糸を行うことで、２ｄｔｅｘの単一繊維からなるウェブを得た。これを不織繊維集合体（III）として用いた。
実施例４で採取した不織繊維集合体（Ｉ）、不織繊維集合体（II）と前記不織繊維集合体（III）をそれぞれ上層、下層、中層に位置するように堆積させ、線圧６０Ｎ／ｍｍ、圧着面積率１５％、熱処理温度エンボスロール／フラットロール＝１４５／１０５℃のエンボス熱圧着装置により熱圧着処理し、複合化不織布を得た。得られた複合化不織布は表１に見られるように、実施例４と比較して、耐毛羽立ち性が劣る傾向であった。
【００４４】
実施例から分かるように本発明の複合化不織布は、熱可塑性樹脂（Ａ）を原料とする不織繊維集合体（Ｉ）と熱可塑性樹脂（Ｂ）を原料とする不織繊維集合体（II）で構成された不織繊維集合体層間に、熱可塑性樹脂（Ａ）及び熱可塑性樹脂（Ｂ）の両成分が繊維表面に露出した複合繊維で構成された不織繊維集合体（III）を配した複合化不織布であるため、それぞれ該熱可塑性樹脂（Ａ）と該熱可塑性樹脂（Ｂ）の軟化温度で熱処理加工を行なうことで、層間同士が十分に溶融接着をする。このため十分な不織布強力が得られ、層間剥離や毛羽立ちの発生といった問題が生じないばかりでなく、不織布の風合いをも満足させるものである。
更に該複合化不織布を子供用オムツのトップシートやバックシートに使用したところ、耐毛羽立ち性に問題なく、また触感に優れた十分に満足できるものであった。
【００４５】
【表１】

【００４６】
【発明の効果】
本発明の複合化不織布は非常にソフトで良好な風合いを有する。更に各層間が剥離せず耐毛羽立ち性に優れ、かつ実用上、十分な不織布強力を有するので、吸収性物品やワイパーとして、繊維製品としても利用価値が高い。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite non-woven fabric having a very soft texture, and having non-woven fiber assembly layers not peeling off and also having fuzz resistance, and a fiber product using the same.
[0002]
[Prior art]
Nonwoven fabric obtained from thermocompression processing using thermoplastic fiber as raw material has good productivity and excellent cost, and soft texture and high nonwoven properties (high nonwoven strength) are preferred. It is used for. However, as a recent trend, a softer texture (tactile sensation) is required for the surface material of sanitary materials. In addition, the non-woven fabric's fuzz resistance, which is a problem when using non-woven fabrics on top and back sheets of paper diapers, is an important quality item for non-woven fabric products as well as non-woven fabric strength and texture. Is required.
[0003]
Non-woven fabrics that satisfy all of the fuzz resistance, non-woven fabric strength, and texture are difficult to obtain with a single-layer non-woven fabric. For example, JP-A-5-33257 discloses a polyethylene terephthalate long fiber between two nonwoven fabric layers composed of a sheath-core type composite long fiber having polyethylene terephthalate as a core component and high-density polyethylene as a sheath component. A laminated nonwoven fabric has been proposed that has a three-layer structure in which a configured nonwoven fabric layer exists, and the entire nonwoven fabric is partially thermocompression bonded.
[0004]
In this method, the middle layer polyethylene terephthalate long fibers are made of a resin component having a melting point higher than that of the upper and lower layers, so even if they are partially thermocompression bonded, the middle layer has little adhesion between the fibers, and the long fibers have a relatively high degree of freedom. It becomes a state. At this time, since the fibers of the middle layer are not adhered, the flexibility of the nonwoven fabric is improved, but the strength of the nonwoven fabric is insufficient. Therefore, in order to obtain sufficient strength of the nonwoven fabric, the upper and lower layers of fibers must be processed at a higher temperature, which causes problems such as fusion to a thermocompression roll. Moreover, since adhesion between lamination | stacking is insufficient, when a nonwoven fabric was rubbed together, peeling between lamination | stacking occurred, As a result, the problem remained in fuzz resistance.
[0005]
In order to make up for this drawback, Japanese Patent Application Laid-Open No. H8-41768 includes only a portion composed of the long fiber group A and a long fiber group B composed of a polymer component having a melting point higher than that of the long fiber group A by 20 ° C. There has been proposed a laminated nonwoven fabric in which a long fiber group C having a portion in which the long fiber group A and the long fiber group B are mixed with each other is laminated and thermocompression bonded.
[0006]
In this method, since the fibers of the long fiber group A and the long fiber group B are mixed in the long fiber group C, the separation between the lamination of the long fiber C and the long fiber group A and the long fiber group B is suppressed. An effect is obtained. However, in this method, since the melting point difference between the long fiber group A and the long fiber group B is different, it is necessary to set the processing temperature to the high melting point side or different processing temperatures on the high melting point side and the low melting point side. However, when the processing temperature is adjusted to the high melting point side, the amount of heat applied to the low melting point side becomes excessive, causing a problem that the thermoplastic resin constituting the long fiber group is fused to the processing apparatus. Next, when different processing temperatures were set for the high melting point side and the low melting point side, the amount of heat applied to the long fiber group C, which is the middle layer, seemed to be insufficient, resulting in a problem that separation between the layers occurred. Further, since the long fiber group C is composed of the long fiber group A and the long fiber group B having different melting points, the long fiber group C has a fusion part sufficient for self-adhesion and adhesion between the laminates. As a result, the degree of freedom of the fibers is increased, and there is a problem with insufficient strength of the nonwoven fabric and fuzz resistance.
[0007]
Further, in Japanese Patent No. 3043099, the layer 2 and the layer 3 between the layer 1 composed only of the composite long fiber A and the layer 4 composed only of the composite long fiber B include the composite long fiber group A. And a nonwoven fabric which is a layer (hereinafter referred to as a mixed fiber portion) in which the fiber weight ratio per unit volume of the composite long fiber group B is continuously changed. In this method, the formation of the mixed fiber portion is not uniform, and the mixed fiber unevenness in which the ratio of the composite long fiber A and the composite long fiber B in the mixed fiber portion is biased results in poor adhesion between layers. As a result, peeling between the layers has been a problem.
[0008]
The greatest effect in improving the fluff resistance is to increase the adhesion area ratio of the nonwoven fabric surface. However, if the adhesion area ratio is increased, the texture of the nonwoven fabric is impaired. Further, when the processing temperature is increased, fusion or winding to the thermocompression-bonding roll occurs. Further, the damage received by the fiber at the edge portion of the crimping point is increased, and the fiber is easily cut and the fuzz resistance is deteriorated. On the other hand, the method of keeping the processing temperature low results in insufficient strength of the nonwoven fabric and delamination because the thermal bonding inside the nonwoven fabric becomes insufficient. That is, when emphasis is placed on the texture of the nonwoven fabric, problems such as deterioration of fuzz resistance and delamination occur. On the other hand, when emphasis is placed on the fuzz resistance, there has been a problem such as deterioration in operability due to the texture of the nonwoven fabric and fusion or winding to the thermocompression bonding roll.
As described above, various nonwoven fabric production methods have been proposed which have both the texture of the nonwoven fabric and the adhesive strength between the nonwoven fabric laminates and the fuzz resistance, but no satisfactory nonwoven fabric has been obtained.
[0009]
[Problems to be solved by the invention]
The objective of this invention is providing the composite nonwoven fabric which has the adhesive strength between a nonwoven fabric texture and a nonwoven fabric lamination | stacking, and fuzz-proof property, and a fiber product using the same.
[0010]
[Means for Solving the Problems]
The present inventors have made extensive studies to solve the above problems. As a result, the prospect of achieving the intended purpose was obtained by adopting the following configuration, and the present invention was completed based on this knowledge.
(1) Between the laminates of both nonwoven fabrics composed of the nonwoven fiber aggregate (I) made from the thermoplastic resin (A) and the nonwoven fiber aggregate (II) made from the thermoplastic resin (B) And a non-woven fabric aggregate (III) composed of a composite fiber in which both components of the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface, Nonwoven fabric aggregate (III) is a composite nonwoven fabric characterized by being thermally bonded to the nonwoven fabric aggregate (I) and the nonwoven fabric aggregate (II).
(2) The thermoplastic resin (A), which is the raw material of the nonwoven fiber assembly (I), or the thermoplastic resin (B), which is the raw material of the nonwoven fiber assembly (II), is low density polyethylene and linear At least one different kind selected from the group consisting of low density polyethylene, high density polyethylene, polypropylene, propylene-based binary copolymer, propylene-based terpolymer, olefin-based resin, polyester, and copolymerized polyester. The composite nonwoven fabric according to (1) above, which is a thermoplastic resin or the same kind of thermoplastic resin having a different melting point.
(3) The nonwoven fiber assembly (I) is a composite fiber composed of a thermoplastic resin (A) and a thermoplastic resin (A ′) having a melting point higher by 10 ° C. than the thermoplastic resin (A). The composite nonwoven fabric according to (1) or (2).
(4) The nonwoven fiber aggregate (II) is a composite fiber composed of a thermoplastic resin (B) and a thermoplastic resin (B ′) having a melting point 10 ° C. higher than that of the thermoplastic resin (B). The composite nonwoven fabric according to (1) or (2).
(5) The composite nonwoven fabric according to any one of (1) to (4), wherein the nonwoven fiber assemblies (I), (II), and (III) are long-fiber nonwoven fabrics.
(6) The composite nonwoven fabric according to any one of (1) to (5) above and at least one selected from other nonwoven fabrics other than the composite nonwoven fabric, film, pulp sheet, knitted fabric, and woven fabric Laminated composite nonwoven fabric with laminated layers.
(7) An absorbent article using the composite nonwoven fabric according to any one of (1) to (5) or the laminated composite nonwoven fabric according to (6).
(8) A wiper using the composite nonwoven fabric according to any one of (1) to (5) or the laminated composite nonwoven fabric according to (6).
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
The composite nonwoven fabric of the present invention is composed of a nonwoven fiber aggregate (I) made from a thermoplastic resin (A) as a raw material and a nonwoven fiber aggregate (II) made from a thermoplastic resin (B) as a raw material. A composite comprising a non-woven fiber assembly (III) composed of a composite fiber in which both components of the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface is disposed between the laminates of both nonwoven fabrics. The nonwoven fabric aggregate (III) is a non-woven fabric and is bonded to the nonwoven fiber assembly (I) and the nonwoven fiber assembly (II) by thermal bonding. That is, the web on the non-woven fiber assembly (I) side is thermally bonded at the softening point of the thermoplastic resin (A), and the web on the non-woven fiber assembly (II) side is softening point of the thermoplastic resin (B). Thermal bonding is performed at. That is, the non-woven fiber assembly (I) side is thermally bonded to the thermoplastic resin (A) of the non-woven fiber assembly (III), and the non-woven fiber assembly (II) side is non-woven fiber assembly (III). The thermoplastic resin (B) is thermally bonded. Therefore, since the nonwoven fiber aggregate (I) and the nonwoven fiber aggregate (II) on the surface are sufficiently bonded to the nonwoven fiber aggregate (III), sufficient nonwoven fabric strength can be obtained, Since the degree of freedom is also suppressed, it is possible to prevent peeling between the nonwoven fabric laminates, and since the fabric is not excessively damaged by heat, the texture of the nonwoven fabric is improved.
[0012]
By the way, the non-woven fiber assembly (I), the non-woven fiber assembly (II) and the non-woven fiber assembly (III) can be integrated by either a hot air heating method or a thermocompression processing method. However, a thermocompression bonding method represented by an embossing device is more preferably used.
Since thermocompression processing is a processing method using heat and pressure, it can be bonded at a temperature lower than the melting point of the low-melting-point resin to be welded and is more productive than hot air heating processing, which is a processing method using hot air. Very good in terms.
[0013]
When a nonwoven fiber assembly is integrated using thermocompression processing (embossing roll processing), the fuzz resistance is highly dependent on the embossed area ratio (convex portion) and processing temperature. Therefore, since the thermoplastic composite nonwoven fabric of the present invention has the same resin component as the upper and lower layers in the middle layer portion, at the processing temperature that does not damage the nonwoven fabric surface, the entire interior contributes sufficiently to the adhesiveness. Control the degree of freedom of the fiber. For this reason, in the case of the same embossed area ratio, compared with the conventional nonwoven fabric, it is excellent in a feel and fuzz resistance, and sufficient nonwoven fabric strength is also obtained. Moreover, roll seizure due to the molten resin can be suppressed, and stable production (operability) can be obtained. In the conventional technology, when the bonding area ratio is lowered, the fiber freedom on the nonwoven fabric surface increases, whereas when the processing temperature is lowered, the fiber freedom inside the nonwoven fabric increases, so both tend to have reduced fuzz resistance. there were.
[0014]
In the composite form of the non-woven fiber assembly (III) in the composite nonwoven fabric of the present invention, both the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface, and the cross-sectional area ratio is the same. The cross-sectional shape is suitable, and the cross-sectional shape may be various irregular cross-sectional shapes such as a radiation type and a radiation hollow type in addition to a circular shape. Moreover, the structure in which thermoplastic resins other than a thermoplastic resin (A) and a thermoplastic resin (B) are contained in the fiber in the range which does not inhibit the effect of invention may be sufficient. Furthermore, the volume ratio V of the thermoplastic resin (A) to the thermoplastic resin (B) _A / V _B Is preferably 7/3 to 3/7, more preferably 4/6 to 6/4, in order to achieve uniform bonding strength between the nonwoven fiber assembly (I) and the nonwoven fiber assembly (II). preferable.
[0015]
In the present invention, the combination of the thermoplastic resin (A) and the thermoplastic resin (B) is not particularly limited, but the combination of the thermoplastic resin (A) / thermoplastic resin (B) is high density polyethylene / polypropylene, low Density polyethylene / polypropylene, linear low density polyethylene / polypropylene, binary copolymer of propylene and other α-olefins or terpolymer / binary copolymer or ternary of propylene and other α-olefins Copolymer, linear low density polyethylene / high density polyethylene, low density polyethylene / high density polyethylene, low density polyethylene / linear low density polyethylene, linear low density polyethylene / propylene and other alpha olefins Original copolymer or terpolymer, binary copolymer of low density polyethylene / propylene and other α-olefins or Copolymer, binary copolymer or ternary copolymer of high-density polyethylene / propylene and other α-olefin, binary copolymer or terpolymer of propylene and other α-olefin, or polypropylene / polypropylene And linear low density polyethylene / polyester, low density polyethylene / polyester, high density polyethylene / polyester, copolymer polyester / polyester, nylon 6 / nylon 66, and the like. Among these, combinations of the same component resins having a difference in melting point such as propylene resin / propylene resin, polyethylene resin / polyethylene resin, polyester resin / polyester resin, polyamide resin / polyamide resin, The adhesive effect is large and is preferably used.
[0016]
As the polyethylene used for the thermoplastic resin (A) and the thermoplastic resin (B) in the present invention, a polyethylene resin that is usually used industrially is preferably used. For example, the density is 0.910 to 0.925 g / cm. ^Three Low density polyethylene, density 0.926-0.940 g / cm ^Three Linear low density polyethylene with a density of 0.941 to 0.980 g / cm ^Three Can be mentioned. In particular, polyethylene having a melt flow rate (MI: a value measured according to condition 4 in JIS K7210 Table 1) in the range of 2 to 100 g / 10 min is preferable.
[0017]
In the present invention, the polypropylene used for the thermoplastic resin (A) and the thermoplastic resin (B) is preferably a homopolypropylene, a propylene-based binary copolymer, or a propylene-based terpolymer. MFR: JISK7210 (value measured according to condition 14 in Table 1) is preferably 2 to 150 g / 10 min, and a melting point of 120 to 165 ° C is preferred.
[0018]
In the present invention, the propylene-based binary copolymer and propylene-based terpolymer used for the thermoplastic resin (A) and the thermoplastic resin (B) are composed mainly of propylene and a small amount of ethylene, 1 Preferred are crystalline copolymers with α-olefins such as -butene, 1-hexene, 1-octene, or 4,4′-dimethyl 1-pentene, and in particular, MFR is 2 to 150 g / 10 min and melting point is 120. Propylene-based binary copolymers and propylene-based terpolymers in the range of ˜158 ° C. are preferably used. Specific examples include a propylene / ethylene binary copolymer composed mainly of propylene and containing 99 to 85% by weight of propylene units and 1 to 15% by weight of ethylene units, 99 to 50% by weight of propylene units, and 1-butene. A propylene / 1-butene binary copolymer mainly composed of 1 to 50% by weight of propylene units, or 84 to 98% by weight of propylene units, 1 to 10% by weight of ethylene units, and 1 of 1-butene units. And a terpolymer of propylene / ethylene / 1-butene containing ˜15% by weight.
[0019]
The thermoplastic resin used in the present invention further includes an antioxidant, a light stabilizer, an ultraviolet absorber, a neutralizer, a nucleating agent, an epoxy stabilizer, a lubricant, and an antibacterial agent within the range not impeding the effects of the present invention. In addition, flame retardants, antistatic agents, pigments, plasticizers, hydrophilic agents and the like may be appropriately added as necessary. The composite nonwoven fabric of the present invention may be subjected to an adhesion treatment with a surfactant or the like, if necessary.
[0020]
The fiber structure of the nonwoven fiber assembly (I) used in the composite nonwoven fabric of the present invention may be a single fiber of the thermoplastic resin (A), and the thermoplastic resin (A) is a sheath component, and from the (A) Or a composite fiber having a thermoplastic resin (A ′) having a melting point higher by 10 ° C. or more as a core component, more preferably a thermoplastic resin (A ′) having a melting point higher by 30 ° C. or more than (A). A composite fiber as a component is desirable.
[0021]
Further, the fiber structure of the nonwoven fiber assembly (II) used in the composite nonwoven fabric of the present invention may be a single fiber of the thermoplastic resin (B), and the thermoplastic resin (B) is a sheath component, and the (B) It may be a composite fiber having a thermoplastic resin (B ′) having a melting point higher by 10 ° C. or more as a core component, more preferably a thermoplastic resin (B ′) having a melting point higher by 30 ° C. or more than (B). A composite fiber as a core component is desirable.
[0022]
There are no particular limitations on the fibers constituting the non-woven fiber assembly (I), non-woven fiber assembly (II), and non-woven fiber assembly (III) used in the composite nonwoven fabric of the present invention. Fibers or long fibers can be used. For example, when a short fiber made of a composite fiber is used as a fiber, the production method is a known composite using a spinneret plate having a fiber cross section such as a parallel type, a sheath core type, an eccentric sheath core type, or a multi-segment type. Spinning by the spinning method, after drawing the obtained undrawn yarn with a drawing machine, further crimping the obtained drawn yarn with a crimper, cutting it into a desired cut length with a cutter to make short fibers A method can be exemplified. Of these, the composite type is preferably a concentric type having excellent dimensional stability. Further, it is possible to make a chop by straight cutting without applying crimp after stretching.
Also illustrated is a known melt-blow manufacturing method in which a polymer stream melt-spun from a spinning machine is pulled and thinned by a high-temperature high-pressure air stream, and collected and deposited on a moving collection surface to form a web. it can. In addition, the fiber obtained by the melt blow method is also mentioned as a representative of the short fiber.
On the other hand, when using a long fiber made of a composite fiber as a fiber, the production method is a spinneret plate having a fiber cross section such as a parallel type, a sheath core type, an eccentric sheath core type, or a multi-segment type. A method of manufacturing by the bond method can be exemplified. In addition, as a fiber, not only a composite fiber but a single fiber can also be used.
[0023]
The fineness and basis weight of the fibers constituting the composite nonwoven fabric of the present invention are not particularly limited, but are 0.01 to 11 dtex (hereinafter referred to as dtex) and 5 to 40 g / g in terms of texture and flexibility, respectively. m ² Are preferred, more preferably 0.03-7 dtex, 8-30 g / m ² It is. The basis weight is 5g / m ² If it is less than 1, sufficient nonwoven fabric strength cannot be obtained, conversely 40 g / m ² However, it is not suitable for surface materials such as sanitary materials.
Moreover, the composite weight ratio (wt% of sheath component / wt% of core component) in the case of using a composite fiber is preferably in the range of 20/80 to 70/30, more preferably 40/60 to 60/40. . If the sheath component is less than 20% by weight, the resulting fiber has insufficient thermal adhesiveness. Conversely, if the sheath component exceeds 70%, the composite fiber shrinks during heat treatment, and the dimensional stability of the resulting fabric decreases. Tend to.
[0024]
The ratio of the basis weight of the non-woven fiber assembly (I), the non-woven fiber assembly (II) and the non-woven fiber assembly (III), which are constituents of the composite non-woven fabric of the present invention, Greatly related to physical properties. The ratio of the basis weight of the nonwoven fiber aggregate (I) to the basis weight of the nonwoven fiber aggregate (III) is preferably 0.2 to 5. Especially preferably, it is 0.3-4. When this basis weight ratio greatly exceeds 5, when heat-treated, the adhesiveness of the nonwoven fabric is lowered, and there is a difficulty in peeling between layers and fuzz resistance. If it is less than 0.2, the fuzz resistance is improved, but the texture of the nonwoven fabric may be impaired. The ratio of the basis weight of the nonwoven fiber assembly (II) / the basis weight of the nonwoven fiber assembly (III) is preferably 0.2 to 5. Especially preferably, it is 0.3-4. When this basis weight ratio greatly exceeds 5, when heat-treated, the adhesiveness of the nonwoven fabric is lowered, and there is a difficulty in peeling between layers and fuzz resistance. If it is less than 0.2, the fuzz resistance is improved, but the texture of the nonwoven fabric may be impaired. Further, the basis weight ratio of the nonwoven fiber assembly (I) and the nonwoven fiber assembly (II) is not limited to the same ratio, and can be arbitrarily selected.
[0025]
When the nonwoven fiber assembly (I), the nonwoven fiber assembly (II), and the nonwoven fiber assembly (III) of the present invention are integrated by thermocompression bonding, the manufacturing apparatus is not particularly limited, Usually, a thermocompression bonding apparatus comprising a pair of embossing rolls and flat rolls is used. At this time, the crimping temperature is determined by the melting point of the resin constituting the nonwoven fabric. However, if there is a sufficient melting point difference between the nonwoven fiber assembly (I) and the nonwoven fiber assembly (II), peeling between the layers is prevented. In order to prevent this, it is desirable to set a higher roll temperature on the high melting point side of both. Moreover, the range of 5-30% is preferable with respect to the nonwoven fabric total area, More preferably, the embossed area ratio is 9-22%. If the area of the fusion zone is less than 5%, there is a concern about delamination between the nonwoven fabric laminates, and if it exceeds 30%, the texture may be impaired.
[0026]
In the composite nonwoven fabric of the present invention, other nonwoven fabrics, films, pulp sheets, knitted fabrics, and woven fabrics can be laminated as long as the effects are not hindered to obtain a laminated composite nonwoven fabric. Moreover, the composite nonwoven fabric which laminates another nonwoven fabric, a film, a pulp sheet, a knitted fabric, and a woven fabric may be laminated | stacked independently, respectively, and the composite nonwoven fabric of this invention may be laminated | stacked, and may be laminated | stacked in combination. There are no restrictions on the material, and various materials can be used. However, it is preferable to include a material that can be bonded to the base nonwoven fabric, and more preferable to be a material that can be bonded.
[0027]
The composite nonwoven fabric and laminated composite nonwoven fabric of the present invention can be used as a material for absorbent articles. In particular, it can be particularly preferably used as sanitary materials such as disposable diapers for infants and adults, napkins, sweat-absorbing pads, sebum removing sheet materials, and towels. Furthermore, the composite nonwoven fabric and laminated composite nonwoven fabric of the present invention can be preferably used as a wiper. Examples include household disposable wipes, window wipes, floor wipes, tatami wipes, and the like. In addition, it can also be used as a disposable seat cover, toilet seat cover, clothes warming agent, mold base material, etc. for airplanes and passenger vehicles.
[0028]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited at all by these. In addition, the measuring method and sensory evaluation of the physical property in an Example and a comparative example are as follows.
[0029]
(1) Melting point of thermoplastic resin (melting point after fiber molding)
MP (° C.): Measured according to JIS K7122.
[0030]
(2) Non-woven texture
A sensory test was conducted by 10 panelists, and 8 or more people were judged to be soft, 6 to 7 people were judged to be soft, and 5 or more were judged to lack softness. The case was evaluated as “impossible”, and “Excellent” was indicated by “Good”, “Good” by “△”, and “No” by ×.
[0031]
(3) Strong nonwoven fabric (MD direction)
The machine direction of the nonwoven fabric was the MD direction, the direction perpendicular to the machine flow direction was the CD direction, and the test piece was cut out from the nonwoven fabric with the following size. Five strips of 15 cm in the MD direction and 2.5 cm in the CD direction were cut out from the nonwoven fabric to obtain a sample for measuring the strength of the nonwoven fabric. The strength of this test piece was measured using an autograph AGS500D manufactured by Shimadzu Corporation under the conditions of a grip interval of 10 cm and a tensile speed of 10 cm / min, and the maximum strength (N / 2.5 cm) was obtained. The measurement was performed once per sheet, a total of five measurements were performed, and the average value was calculated. The average value was the nonwoven fabric strength value of the sample.
[0032]
(4) Evaluation of fuzz resistance
Below, the method for evaluating the fluff resistance (hardness of fluffing) of the obtained nonwoven fabric is described. The evaluation method conforms to JIS L0849-1974.
(1) As a test piece, a nonwoven fabric to be evaluated is cut into a size of 4 cm in the MD direction and 20 cm in the CD direction, and four pieces thereof are prepared. Further, the nonwoven fabric to be evaluated is cut into a size of 20 cm in the MD direction and 4 cm in the CD direction, and four of them are prepared.
(2) A double-sided tape having a width of 3.5 cm and a length of 20 cm is attached to the center of the nonwoven fabric sample in the longitudinal direction. At this time, for each MD / CD, two nonwoven fabric samples on the embossed roll treated surface side and the flat roll treated surface side are prepared.
(3) A non-woven fabric sample is attached to a sample table of a friction tester (manufactured by Suga Test Instruments Co., Ltd.), and a No. 3 cloth (4 cm × 5 cm) is attached to the friction element.
{Circle around (4)} Place the friction element on the nonwoven fabric sample, and perform a reciprocating 150 times friction test. The rubbing condition (generation of fluff and fluffing condition) on the surface of the nonwoven fabric at this time is sensorially evaluated based on the following criteria (sensory index).
Judgment criteria (sensory index)
A: Neither fluff nor fluff is observed.
○: Slight fuzz is observed.
(Triangle | delta): A lot of fluff and fluff are observed.
X: A lot of fuzz and a plurality of fuzz balls are observed.
[0033]
Example 1
Using a crystalline polypropylene having a melting point of 160 ° C. and an MFR of 36 g / 10 min as the thermoplastic resin (A), spinning was performed by a known spunbond method to produce a nonwoven fiber assembly (I). Specifically, the crystalline polypropylene was put into a spinning machine, melted by heat, and discharged as a single long fiber group from a spinneret. Next, the long fiber was pulled and drawn by passing it through an air soccer ball to obtain a single long fiber of 2 dtex. Further, after the discharged long fiber group is charged by a charging device, it is opened by colliding with a reflecting plate, collected on an endless net-like conveyor provided with a suction device on the back surface, and a single long fiber web Got. This web was used as the nonwoven fiber assembly (I).
Similarly, as the thermoplastic resin (B), propylene having a melting point of 139 ° C., an MFR of 38 g / 10 min, 3% by weight of ethylene units, 2% by weight of 1-butene units, and 95% by weight of propylene units. Spinning was performed by the same spunbond method using the system ternary copolymer, and similarly, a single long fiber web composed of single long fibers of 2 dtex was obtained. This web was used as a nonwoven fiber assembly (II).
Further, as the thermoplastic resin (A), a crystalline polypropylene having a melting point of 160 ° C. and an MFR of 36 g / 10 min is used, and as the thermoplastic resin (B), the melting point is 139 ° C. and the MFR is 38 g / 10 min. Using a propylene-based terpolymer containing 3% by weight of ethylene units, 2% by weight of 1-butene units and 95% by weight of propylene units, spinning is performed by a known spunbond method, and a non-woven fiber assembly Body (III) was produced. Specifically, the two types of thermoplastic resins were put into a spinning machine, melted by heat, and discharged from a parallel composite spinneret as a parallel composite fiber group. Next, the composite fiber was pulled and drawn by passing it through an air soccer ball to obtain a 2 dtex parallel type composite long fiber. Further, after the discharged parallel composite long fiber group is charged by a charging device, the long fiber group is opened by colliding with a reflecting plate, and collected on an endless net-like conveyor provided with a suction device on the back surface. Thus, a composite long fiber web was obtained. This was used as a nonwoven fiber assembly (III).
Non-woven fiber aggregate (II), non-woven fiber aggregate (III) and non-woven fiber aggregate (I) are deposited so as to be located in the lower layer, middle layer and upper layer, respectively, linear pressure 60 N / mm, crimping area ratio The composite nonwoven fabric was obtained by thermocompression bonding using an embossing thermocompression bonding apparatus of 15%, heat treatment temperature embossing roll / flat roll = 145/125 ° C. As shown in Table 1, the obtained composite nonwoven fabric was excellent in texture, nonwoven fabric strength, and fuzz resistance.
[0034]
Example 2
Polyethylene terephthalate having a melting point of 260 ° C. and an intrinsic viscosity of 0.65 was used as the thermoplastic resin (A), and spinning was performed by a known melt spinning method to produce a nonwoven fiber assembly (I). First, this polyethylene terephthalate was put into a spinning machine, melted by heat, and discharged from a spinneret as a single fiber group to obtain an undrawn yarn having a single yarn fineness of 6 dtex. Subsequently, the undrawn yarn was drawn 2.4 times with a hot roll, imparted with mechanical crimping, and further subjected to a cutting treatment to obtain a single fiber of 2.5 dtex × 38 mm. The obtained single fiber was carded with a roller card machine to obtain a web. This was used as the nonwoven fiber assembly (I).
Similarly, as the thermoplastic resin (B), using a high-density polyethylene having a melting point of 130 ° C. and an MI of 35 g / 10 minutes, spinning is performed by a known melt spinning method, and the nonwoven fiber aggregate (II) is obtained. Manufactured. First, the high-density polyethylene was put into a spinning machine, melted by heat, and discharged from a spinneret as a single fiber group to obtain an undrawn yarn having a single yarn fineness of 8 dtex. Subsequently, the undrawn yarn was drawn 2.0 times with a hot roll, imparted with mechanical crimping, and further subjected to cutting treatment to obtain a single fiber of 4.0 dtex × 38 mm. The obtained single fiber was carded with a roller card machine to obtain a web. This was used as a nonwoven fiber assembly (II).
Further, polyethylene terephthalate having a melting point of 260 ° C. and an intrinsic viscosity of 0.65 is used as the thermoplastic resin (A), and a high melting point of 130 ° C. and MI of 35 g / 10 minutes is used as the thermoplastic resin (B). A non-woven fiber assembly (III) was produced by spinning by using an ordinary melt spinning method using a density polyethylene. First, the above-mentioned two types of thermoplastic resins were put into a spinning machine from separate hoppers, thermally melted, and discharged as a composite fiber group from a parallel type composite spinneret to obtain an undrawn yarn having a single yarn fineness of 6 dtex. Subsequently, this unstretched yarn was stretched 2.0 times with a hot roll, imparted with mechanical crimping, and further subjected to cutting treatment to obtain a parallel composite fiber of 3.0 dtex × 38 mm, and the obtained composite fiber Was carded with a roller card machine to obtain a web, which was used as a nonwoven fiber assembly (III).
Non-woven fiber assembly (II), non-woven fiber assembly (III) and non-woven fiber assembly (I) are deposited so as to be located in the lower layer, middle layer and upper layer, respectively, linear pressure 40 N / mm, crimping area The nonwoven fabric was obtained by thermocompression treatment using an embossing thermocompression bonding apparatus having a rate of 15% and a heat treatment temperature of embossing roll / flat roll = 200/115 ° C. As shown in Table 1, the obtained composite nonwoven fabric was excellent in texture, nonwoven fabric strength, and fuzz resistance.
[0035]
Example 3
The non-woven fiber assembly (III) was produced by spinning using the same thermoplastic resin (A) and thermoplastic resin (B) as in Example 1 by a known melt blow method. First, two types of thermoplastic resins were charged into a spinning machine from separate hoppers, melted by heat, and discharged as a composite fiber group from a parallel type spinneret. Next, this was fined by blowing with high-pressure hot air, and collected as a composite short fiber web on an endless net-like conveyor. This was used as a nonwoven fiber assembly (III).
The non-woven fiber assembly (I), non-woven fiber assembly (II) and non-woven fiber assembly (III) collected in Example 1 were deposited so as to be located in the upper layer, the lower layer and the middle layer, respectively, The composite nonwoven fabric was obtained by thermocompression treatment using an embossing thermocompression apparatus of 60 N / mm, crimping area ratio 15%, heat treatment temperature embossing roll / flat roll = 145/125 ° C. As shown in Table 1, the obtained composite nonwoven fabric was very excellent in texture, nonwoven fabric strength, and fluff resistance.
[0036]
Example 4
For the non-woven fiber assembly (I), Using the same thermoplastic resin (A) as in Example 1, A single long fiber web was produced by spinning by a known spunbond method.
For the non-woven fiber assembly (II), a linear low density polyethylene having a melting point of 125 ° C. and MI of 20 g / 10 min is used as the thermoplastic resin (B), the melting point is 159 ° C., and the MFR is 40 g / 10. It was manufactured by performing spinning by a known spunbond method using crystalline polypropylene as a component as a thermoplastic resin (B ′). First, both were put into a spinning machine from separate hoppers, heat-melted, and discharged as a composite fiber group from a sheath-core type spinneret. Next, this was passed through an air soccer ball and discharged to pull and stretch to obtain a 2 dtex sheath-core type composite continuous fiber. Further, after charging the discharged long fiber group with a charging device, it is opened by colliding with a reflecting plate, collected on an endless net-like conveyor provided with a suction device on the back surface, and a composite long fiber web is collected. Obtained. This was used as a nonwoven fiber assembly (II).
Further, as the thermoplastic resin (A), the same thermoplastic resin as in Example 1 is used, and as the thermoplastic resin (B), a linear low density polyethylene having a melting point of 125 ° C. and MI of 20 g / 10 min is used. Then, a 2 dtex composite long fiber web was obtained by a known spunbond method in the same manner as in Example 1, and this was used as the nonwoven fiber assembly (III).
Non-woven fiber aggregate (II), non-woven fiber aggregate (III) and non-woven fiber aggregate (I) are deposited so as to be located in the lower layer, middle layer and upper layer, respectively, linear pressure 60 N / mm, crimping area ratio The composite nonwoven fabric was obtained by thermocompression bonding using an embossing thermocompression bonding apparatus having a heat treatment temperature of 15%, embossing roll / flat roll = 145/105 ° C. As shown in Table 1, the obtained composite nonwoven fabric was very excellent in fuzz resistance, and was excellent in texture and nonwoven fabric strength.
[0037]
Example 5
A high-density polyethylene having a melting point of 130 ° C. and MI of 30 g / 10 min is used as the thermoplastic resin (A), and a crystal having a melting point of 159 ° C. and MFR of 40 g / 10 min is used as the thermoplastic resin (A ′). A non-woven fiber assembly (I) was produced by spinning by using a known spunbond method using a conductive polypropylene. Specifically, with the thermoplastic resin (A) as the sheath component side and the thermoplastic resin (A ′) core component side, both are put into a spinning machine from separate hoppers, melted by heat, and from the sheath core type spinneret. It was discharged as a composite fiber group. Next, this was passed through an air soccer ball and discharged to pull and stretch to obtain a 2 dtex sheath-core type composite continuous fiber. Further, after charging the discharged long fiber group with a charging device, it is opened by colliding with a reflecting plate, collected on an endless net-like conveyor provided with a suction device on the back surface, and a composite long fiber web is collected. Obtained. This was used as the nonwoven fiber assembly (I).
Similarly, as the thermoplastic resin (B), propylene having a melting point of 139 ° C., an MFR of 38 g / 10 min, 3% by weight of ethylene units, 2% by weight of 1-butene units, and 95% by weight of propylene units. Spinning is performed by a known spunbond method using a crystalline terpolymer and crystalline polypropylene having a melting point of 159 ° C. and an MFR of 40 g / 10 min as the thermoplastic resin (B ′). A web made of sheath-core type composite continuous fiber was produced, and this was made into a non-woven fiber assembly (II).
Further, as the thermoplastic resin (A), a high-density polyethylene having a melting point of 130 ° C. and MI of 30 g / 10 min is used, and as the thermoplastic resin (B), a melting point of 139 ° C. and MFR is 38 g / 10 min. Spinning by a known spunbond method using a propylene terpolymer containing 3% by weight of ethylene units, 2% by weight of 1-butene units, and 95% by weight of propylene units, and a 2 dtex parallel type A web composed of composite long fibers was produced and used as a nonwoven fiber assembly (III).
Non-woven fiber aggregate (II), non-woven fiber aggregate (III) and non-woven fiber aggregate (I) are deposited so as to be located in the lower layer, middle layer and upper layer, respectively, linear pressure 40 N / mm, crimping area ratio The composite nonwoven fabric was obtained by thermocompression bonding using an embossing thermocompression bonding apparatus of 15%, heat treatment temperature embossing roll / flat roll = 120/130 ° C. As shown in Table 1, the obtained composite nonwoven fabric was very excellent in texture, and also excellent in nonwoven fabric strength and fuzz resistance.
[0038]
Example 6
When the composite non-woven fabric of the present invention obtained in Example 3 was used as a back sheet for a diaper for children, there was no problem in the resistance to fluffing and an excellent touch was shown.
[0039]
Example 7
When the composite nonwoven fabric of the present invention obtained in Example 1 was used as a wiper for window blowing, it showed very good dust adsorbability.
[0040]
Comparative Example 1
Using the non-woven fiber assembly (I) and non-woven fiber assembly (II) collected in Example 1, they were deposited so as to be located in the upper layer and the lower layer, respectively, linear pressure 60 N / mm, crimping area ratio 15%, Heat treatment temperature embossing roll / flat roll = 145/125 ° C. was thermocompression-bonded with an embossing thermocompression bonding apparatus to obtain a composite nonwoven fabric. As shown in Table 1, the texture of the obtained composite nonwoven fabric tended to be very inferior.
[0041]
Comparative Example 2
As the nonwoven fiber assembly (III), a single fiber of 2.5 dtex × 38 mm polyethylene terephthalate collected in the same manner as the nonwoven fiber assembly (I) of Example 2, and the nonwoven fiber of Example 2 Obtained by mixing high-density polyethylene single fibers of 4.0 dtex x 38 mm collected in the same manner as the assembly (II) at a weight ratio of 50% / 50% and carding with a roller card machine. Web was used.
As the nonwoven fiber aggregate (I), a single fiber of 2.5 dtex × 38 mm polyethylene terephthalate collected by the same method as the nonwoven fiber aggregate (I) of Example 2 is carded with a roller card machine. A web obtained by carding a high-density polyethylene single fiber of 4.0 dtex × 38 mm as a non-woven fiber assembly (II) using a roller card machine. Was used.
A non-woven fiber assembly (III) is laminated between the non-woven fiber assembly (I) and the non-woven fiber assembly (II), the linear pressure is 40 N / mm, the crimping area ratio is 15%, and the embossing roll / flat A heat treatment temperature of the roll = 200/115 ° C. was used for thermocompression bonding to obtain a composite nonwoven fabric.
The obtained composite nonwoven fabric had poor adhesion as a whole as compared with Example 2, the fuzz resistance was very poor, and the nonwoven fabric strength was also low.
[0042]
Comparative Example 3
The non-woven fiber assembly (III) was produced by spinning by a known melt-blowing method using crystalline polypropylene having a melting point of 160 ° C. and an MFR of 36 g / 10 min. First, crystalline polypropylene is put into a spinning machine, heat-melted, discharged as a single fiber group from a spinneret, and further blown with high-pressure hot air to make it finer and single on an endless net-like conveyor. Collected as a short fiber web. This was used as a nonwoven fiber assembly (III).
The nonwoven fiber assembly (I), the nonwoven fiber assembly (II) and the nonwoven fiber assembly (III) collected in Example 3 were deposited so as to be located in the upper layer, the lower layer and the middle layer, respectively, The composite nonwoven fabric was obtained by thermocompression treatment using an embossing thermocompression apparatus of 60 N / mm, crimping area ratio 15%, heat treatment temperature embossing roll / flat roll = 145/125 ° C. The obtained composite nonwoven fabric had a tendency to be inferior in texture as compared with Example 3.
[0043]
Comparative Example 4
The non-woven fiber assembly (III) consists of a single fiber of 2 dtex by spinning by a known spunbond method using crystalline polypropylene having a melting point of 160 ° C. and an MFR of 36 g / 10 min. Got the web. This was used as a nonwoven fiber assembly (III).
The nonwoven fiber assembly (I), the nonwoven fiber assembly (II), and the nonwoven fiber assembly (III) collected in Example 4 were deposited so as to be located in the upper layer, the lower layer, and the middle layer, respectively. The composite nonwoven fabric was obtained by thermocompression treatment using an embossing thermocompression apparatus of 60 N / mm, crimping area ratio 15%, heat treatment temperature embossing roll / flat roll = 145/105 ° C. As shown in Table 1, the obtained composite nonwoven fabric had a tendency to be inferior in fluff resistance as compared with Example 4.
[0044]
As can be seen from the examples, the composite nonwoven fabric of the present invention comprises a nonwoven fiber assembly (I) made from the thermoplastic resin (A) as a raw material and a nonwoven fiber assembly (II) made from the thermoplastic resin (B) as a raw material. Between the non-woven fiber assembly layers composed of) and the non-woven fiber assembly (III) composed of composite fibers in which both components of the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface. Since the composite nonwoven fabric is arranged, the layers are sufficiently melt-bonded to each other by performing heat treatment at the softening temperature of the thermoplastic resin (A) and the thermoplastic resin (B). Therefore, sufficient strength of the nonwoven fabric can be obtained, and not only the problem of delamination and fluffing does not occur, but also the texture of the nonwoven fabric is satisfied.
Further, when the composite nonwoven fabric was used for a top sheet or a back sheet of a diaper for children, there was no problem with the fuzz resistance and it was sufficiently satisfactory with excellent touch feeling.
[0045]
[Table 1]

[0046]
【The invention's effect】
The composite nonwoven fabric of the present invention is very soft and has a good texture. Furthermore, each layer does not peel off, has excellent fuzz resistance, and has practically sufficient non-woven fabric strength, so that it is highly useful as an absorbent article or wiper as a textile product.

Claims

Between the lamination of both nonwoven fabrics composed of the nonwoven fiber assembly (I) made from the thermoplastic resin (A) and the nonwoven fiber assembly (II) made from the thermoplastic resin (B), A non-woven fiber assembly comprising a non-woven fiber assembly (III) comprising a non-woven fiber assembly (III) composed of a composite fiber in which both components of the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface. The thermoplastic resin (A ′) in which the body (I) has a single fiber of the thermoplastic resin (A) or the thermoplastic resin (A) as a sheath component and has a melting point higher by 10 ° C. than the (A). A non-woven fiber assembly (II) having a single fiber of the thermoplastic resin (B) or a thermoplastic resin (B) as a sheath component, and more than the (B) thermoplastic resin having a 10 ° C. or more high melting point (B ') is a composite fiber as a core component, the nonwoven fiber aggregate (III) The non-woven fiber aggregate (I) and non-woven fiber assembly and (II) have been thermally bonded, thermoplastic resin (A nonwoven fiber aggregate (I) side is a nonwoven fiber aggregate (III) ), And the non-woven fiber assembly (II) side is heat-bonded to the thermoplastic resin (B) of the non-woven fiber assembly (III) .

The thermoplastic resin (A) that is the raw material of the non-woven fiber assembly (I) or the thermoplastic resin (B) that is the raw material of the non-woven fiber assembly (II) is a low-density polyethylene and a linear low-density polyethylene, respectively. At least one kind of thermoplastic resin selected from the group consisting of olefin resin, polyester, and copolymer polyester comprising high-density polyethylene, polypropylene, propylene-based binary copolymer, and propylene-based terpolymer Or the composite nonwoven fabric of Claim 1 which is the same kind of thermoplastic resin from which melting | fusing point differs.

Nonwoven fiber aggregate (I), (II), and (III) is, the long-fiber nonwoven fabric in which claims 1-2 according to any one of the combined non-woven fabric.

A laminated composite nonwoven fabric obtained by laminating at least one selected from the composite nonwoven fabric according to any one of claims 1 to 3 and a nonwoven fabric other than the composite nonwoven fabric, a film, a pulp sheet, a knitted fabric, and a woven fabric. .

An absorbent article using the composite nonwoven fabric according to any one of claims 1 to 3 or the laminated composite nonwoven fabric according to claim 4 .

A wiper using the composite nonwoven fabric according to any one of claims 1 to 3 or the laminated composite nonwoven fabric according to claim 4 .

Between the lamination of both nonwoven fabrics composed of the nonwoven fiber assembly (I) made from the thermoplastic resin (A) and the nonwoven fiber assembly (II) made from the thermoplastic resin (B), A non-woven fiber assembly comprising a non-woven fiber assembly (III) comprising a non-woven fiber assembly (III) composed of a composite fiber in which both components of the thermoplastic resin (A) and the thermoplastic resin (B) are exposed on the fiber surface. The thermoplastic resin (A ′) in which the body (I) has a single fiber of the thermoplastic resin (A) or the thermoplastic resin (A) as a sheath component and has a melting point higher by 10 ° C. than the (A). A non-woven fiber assembly (II) having a single fiber of the thermoplastic resin (B) or a thermoplastic resin (B) as a sheath component, and more than the (B) A composite fiber comprising a thermoplastic resin (B ′) having a melting point higher than 10 ° C. as a core component, and the nonwoven fiber aggregate (III) The non-woven fiber aggregate (I) and non-woven fiber aggregate (II), in the range emboss area ratio is 5 to 30% heat-bonding process, a manufacturing method of combined non-woven fabric.