JP3810721B2 - Method for producing stretchable composite sheet - Google Patents

Description

【００２３】
不織布としては、エアスルー不織布、スパンボンド不織布、スパンレース不織布、メルトブローン不織布、又はこれらの複合不織布（例えばスパンボンド／メルトブローン／スパンボンド不織布）など、公知の不織布を用いることができる。不織布を構成する繊維としては、ポリエチレン、ポリプロピレン等のポリオレフィンからなるポリオレフィン系繊維；ポリエチレンテレフタレート、ポリブチレンテレフタレート等のポリエステルからなるポリエステル系繊維；６ナイロン、６，６ナイロン、１２ナイロン等のポリアミド系樹脂からなるポリアミド系繊維、あるいは前記樹脂から成る芯鞘型やサイドバイサイド型の繊維等が用いられる。これらは単独で用いてもよく又は２種以上併用してもよい。これらの繊維の繊度は１〜１０デニールとすることが好ましい。前述の不織布のうち、特に伸縮性が良く、毛羽立ちが少なく、加工性、特に塑性変形が容易である点から、スパンボンド不織布やスパンボンド／メルトブローン／スパンボンド不織布を用いることが好ましい。２枚の不織布３，４は、前述した通り同種でも異種でもよい。各不織布は、その坪量が５〜１００ｇ／ｍ²、特に１０〜５０ｇ／ｍ²であることが、風合い、触感、しっかり感、強度の点から好ましい。
【００２４】
伸縮性シート１全体としての坪量は、１５〜３５０ｇ／ｍ²、特に３０〜２００ｇ／ｍ²であることが、風合い、触感、しっかり感、シート強度の点から好ましい。
【００２５】
伸縮性シート１は、その伸縮方向の破断伸度が３００％以上、特に５００％以上となるような伸張性を有していることが好ましい。また伸縮性シート１はその破断強度が５Ｎ以上、特に１０Ｎ以上であることが、伸縮性シート１を例えば吸収性物品の構成部材として使用する場合にその破れを防止する点から好ましい。また伸縮性シート１は、その１００％伸長時における強度が０．５〜１０Ｎ／２５ｍｍ、特に１〜５Ｎ／２５ｍｍであることが、伸縮性シート１の収縮性及び易伸長性が十分となる点から好ましい。また伸縮性シート１は、伸長方向に１００％伸長した後の永久歪みが３０％以下、特に１５％以下であることが、伸縮性シート１を例えば吸収性物品の構成部材として使用する場合に該吸収性物品のフィット性が良好になる点から好ましい。また伸縮性シート１は、応力−歪み曲線のヒステリシスにおいて、伸縮性シート１を１００％まで伸長させたときの初期変化率（行き）が５％以下、特に３％以下であることが易伸長性と収縮性の点から好ましい。同様の理由及び伸縮性シート１を例えば吸収性物品の構成部材として使用する場合に該吸収性物品のフィット性が良好になる点から、伸縮性シート１を１００％まで伸長させた状態から無張力状態まで戻したときの初期変化率（戻り）が７％以下、特に５％以下であることが好ましい。このような伸縮性を発現させるためには、例えばｉ）エラストマーフィルム２として適切な伸縮性を有するものを用いる、ii）高伸縮領域５と低伸縮領域６との面積比を調整する、iii)高伸縮領域５及び低伸縮領域６それぞれの幅を調整すればよい。
【００２６】
伸縮性シート１の破断強度、破断伸度、１００％伸長時強度並びに初期変化率（行き）及び初期変化率（戻り）は、エラストマーシート２のそれらと同様の方法で測定される。
【００２７】
次に、本実施形態の伸縮性シート１の好適な製造方法について説明する。図２には、伸縮性シート１を製造するために好適な製造装置の模式図が示されている。図２に示す製造装置１０は、エラストマーフィルムと不織布との積層部２０、積層により得られた複合シートの穿孔部３０、及び穿孔により得られた伸縮性シートの巻き取り部４０に大別される。積層部２０は一対のニップロール２１，２１を備えている。エラストマーフィルム及び不織布は、両ニップロール２１，２１間を通過し挟圧されるようになっている。穿孔部３０は一対のロール部材３１，３２を備えている。巻き取り部４０は製造された伸縮性シートのワインダー４１を備えている。
【００２８】
ニップロール２１，２１は一般的には金属製の冷却ロールとゴムロールとの組み合わせからなる。冷却ロールはその表面が、鏡面、梨地、ドットパターン等となっており、目的に応じて使い分けられる。ゴムロールは、天然ゴム、イソプレンゴム、ブタジエンゴム、スチレン・ブタジエンゴム、エチレン・プロピレンゴム、ニトリルゴム、ウレタンゴム、シリコーンゴム等から選択される。その硬度はＡ硬度５０からＤ硬度９５まで目的に応じて使い分けられる。ニップロール２１，２１間にはクリアランス調整機構（図示せず）を取り付け、ニップ圧を調整するようにしてもよい。
【００２９】
穿孔部３０の拡大図を図３に示す。穿孔部３０を構成する一方のロール部材３１は、多数の条溝３３，３３，・・が、ロールの円周方向に沿って多列に配列された受けロールから構成されている。一方、他方のロール部材３２は、受けロール３１に形成されている条溝３３内に進入可能な穿孔３４ピンが該条溝３３に対応する位置に配列された穿孔ロールから構成されている。各穿孔ピン３４は、ロールの円周方向に沿って、所定間隔を置いて多列に配列されている。穿孔ピン３４はその先端が尖形になっており、シートを貫通し易くなっている。穿孔ピン３４はその横断面が円形になっている。その半径は０．１〜１０ｍｍ程度となっている。穿孔ロール３２には加熱手段が備えられており、該加熱手段によって穿孔ピン３４が加熱可能になっている。シートの材質によっては穿孔ピン３４を加熱しなくてもよい。穿孔ピン３４の温度は、エラストマーフィルム及び不織布の構成樹脂にもよるが一般に、当該構成樹脂の融点との関係で、１０〜１００℃、特に１０〜８０℃であることが好ましい。穿孔ピン３４は、その先端の近傍に条溝３３の幅よりも若干狭幅の鍔部（図示せず）を有している。つまり鍔部は、穿孔ピン３４の先端から若干下方の位置において、穿孔ピン３４の高さ方向と直交する方向（水平方向）へ延出している。鍔部の詳細については後述する。
【００３０】
以上の構成を有する製造装置１０を用いた伸縮性シート１の製造方法について説明すると、先ず、Ｔダイ２３から溶融押出されて形成されたエラストマーフィルム２は、未固化の状態で、その各面に不織布３，４がそれぞれ積層され、ニップロール２１，２１に挟み込まれる溶融ラミネート法によって積層一体化される。各不織布３，４は、エラストマーフィルムとは別に製造しておく。溶融ラミネート法においては、押出機等によりエラストマーをその融点以上の温度で溶融状態とし、Ｔダイ２３から押し出した後、環境温度に対して自然的に冷却する。この冷却過程で、未固化の状態のエラストマーフィルムが不織布とニップロール２１，２１で挟み込まれる。ニップロールにおける冷却ロールの温度は０〜５０℃に設定することが好ましい。エラストマーフィルムと不織布の接着力を調整するために、ニップ圧は０．１〜１ＭＰａとするのが好ましい。ニップロールのクリアランス量は使用する不織布によっても異なるが、０〜１．５ｍｍとすることが好ましい。
【００３１】
エラストマーフィルムと不織布との接合に溶融ラミネート法を用いることで、他の接合方法、例えば接着剤を用いた接合に比べて、製造工程を簡略化できるという利点がある。また、生産性が良く、製造コストが低いという利点もある。
【００３２】
複合シート１’は、エラストマーフィルムと不織布との幅方向（ＣＤ）剥離強度が０．５〜５Ｎ／２５ｍｍとなるように溶融ラミネートされることが、不織布の塑性変形のし易さ、伸縮性、毛羽立ち防止の点から好ましい。剥離強度は次の方法によって測定される。幅２５ｍｍの短冊状の試料を作製する。この試料の長手方向一端部において、エラストマーフィルムと不織布との接合面を手で剥離させる。剥離させたエラストマーフィルムと不織布とを、伸長試験機にチャック間距離５０ｍｍとなるように無張力で固定する。次いで試料を３００ｍｍ／ｍｉｎの速度で引っ張りエラストマーフィルムと不織布との接合面を剥離させる。そのときの強度を測定し、極大値の高い方から３点と、極小値の低い方から３点との合計６点の平均値を算出する。この値を剥離強度とする。
【００３３】
得られた複合シート１’は次に穿孔部３０において受けロール３１と穿孔ロール３２との間に介在させられる。各ロール３１，３２は、図２において矢印で示す方向に回転している。この回転によって穿孔ロール３２に取り付けられている穿孔ピン３４は、複合シート１’を貫通して、該穿孔ピン３４と対応する位置に位置する条溝３３内に進入する。この状態を図４（ａ）に示す。
【００３４】
図４（ａ）に示すように、穿孔ピン３４が複合シート１’を貫通するときには、穿孔ピン３４の先端近傍に設けられた鍔部３５によって、穿孔ピン３４が複合シート１’を過度に貫通することが抑制される。これと共に、鍔部３５における穿孔ピン先端側の面によって、穿孔ピン３４の進入位置及びその近傍に位置する複合シート１’が該面によって押さえつけられる。これらの作用によって、穿孔ピン３４の進入位置及びその近傍に位置する不織布は、実質的に塑性変形されることが規制され、複合シート１’の穿孔のみが行われる。
【００３５】
一方、各条溝３３間においては、穿孔ピン３４の進入及び穿孔ピン３４における前記面の押さえつけによって、複合シート１’は引き延ばされる。その結果、複合シート１’におけるエラストマーフィルムは弾性伸張し、また両不織布は塑性変形する。この塑性変形によって、各不織布はその不織布構造の一部が破壊され、変形前に比べて毛羽立ちが生じる。この状態を図４（ｂ）に示す。図４（ｂ）は、図４（ａ）において受けロール３１及び穿孔ロール３２を取り除いた状態に相当する。図４（ｂ）から明らかなように、複合シート１’においては、条溝３３，３３間に位置する領域が引き延ばされていると共に、穿孔ピン３４の進入位置及びその近傍に位置する複合シート１’は実質的に引き延ばされておらず、穿孔前の状態をほぼ保っている。引き延ばされていない領域には開孔７が形成される。引き延ばされた領域及び実質的に引き延ばされていない領域は、それぞれ複合シート１’の搬送方向に沿って互いに交互に延びている。引き延ばされた領域は、最終的に得られる伸縮性シート１における高伸縮領域５となる。一方、実質的に引き延ばされていない領域は、最終的に得られる伸縮性シート１における低伸縮領域６となる。このように、本実施形態においては、穿孔ピン３４の進入位置及びその近傍に存する不織布を実質的に塑性変形させることなく複合シート１’を穿孔して多列に配列された多数の開孔を形成すると同時に、該開孔の列間の位置における不織布を引き延ばして塑性変形させている。
【００３６】
穿孔ピン３４による開口の面積、高伸縮領域５における不織布の塑性変形量は、穿孔ロール３２が受けロール３１にかみ込む量に大きく左右される。そのかみ込み量は、得られる伸縮性シート１の伸縮性の点から０．５〜１０ｍｍ、特に１〜５ｍｍとすることが好ましい。両ロール３１，３２の回転が進むと、複合シート１’に進入した穿孔ピン３４が、該複合シート１’から引き抜かれる。その結果、エラストマーフィルムの弾性収縮作用によって、開孔７は閉じるか、或いは実質的に開口していない状態となる。
【００３７】
このようにして、複合シート１’が穿孔部３０を通過することによって、開孔７が形成されると同時に低伸縮領域６及び高伸縮領域５が形成されて、伸縮性シート１が得られる。伸縮性シート１は巻き取り部４０においてワインダー４１に巻き取られる。
【００３８】
本発明は前記実施形態に制限されない。例えば前記実施形態の伸縮性シートは３層構造のものであったが、これに代えてエラストマーフィルムと不織布とからなる２層構造でもよい。或いは４層以上の多層構造でもよい。
【００３９】
また、エラストマーフィルムと不織布との接合手段として、前記実施形態では溶融ラミネート法を用いたが、これに接着剤による接着を併用してもよい。接着剤の塗工方法としては、スロットスプレー法、カーテンスプレー法、スパイラルスプレー法、メルトブローン法、ビード法、グラビア法、コーター法等がある。接着剤の種類としては、スチレン−イソプレン−スチレン（ＳＩＳ）、スチレン−ブタジエン−スチレン（ＳＢＳ）、それらの混合物をベースにした、いわゆるゴム系、ポリオレフィン系、エチレン−酢酸ビニル系、ポリアミド系、ポリエステル系のもの等がある。その塗工量は前述した剥離強度を得る観点から、０．３〜１０ｇ／ｍ²であることが好ましい。
【００４０】
また前記実施形態では伸縮性シート１を、積層部２０、穿孔部３０及び巻き取り部４０を備えた装置を用いて一連の工程で製造したが、これに代えて、異なる２工程で伸縮性シート１を製造してもよい。例えば、エラストマーシート２と不織布３，４とを溶融ラミネート法によって積層一体化して複合シート１’を得て、これを一旦巻き取った後、巻き取られた複合シート１’を吸収性物品の製造ラインに取り付け、次いで複合シート１’を繰り出して穿孔工程を行って伸縮性シート１を得、更にこれをインランインで吸収性物品に組み込んでもよい。
【００４１】
また、複合シート１’を穿孔した後に不織布構造の一部破壊によって毛羽立ちが多く生じたり、不織布とエラストマーフィルムとの間の剥離強度が低下してしまう場合には、穿孔の前、後、又は前後共にエンボス加工を行うことが好ましい。エンボス加工は、例えば、ゴム製ロール、金属製ロール、ペーパーロール及びコットンロール等の何れかと、模様が彫られた金属製ロールとの間にシートを通す方法等で行われる。エンボス加工は加熱下に行うことが効果的である。エンボスパターンとしては一般的な種々のものが用いられる。伸縮性を阻害しない点からは、ドットパターンが好ましく用いられる。
【００４２】
また、前記実施形態においては、高伸縮領域及び低伸縮領域の形成と、低伸縮領域における開孔の形成とを同時に行ったが、これに代えて先ず高伸縮領域及び低伸縮領域を形成し、然る後に低伸縮領域における開孔の形成を行っても良い。しかしながら、高伸縮領域及び低伸縮領域の形成と、低伸縮領域における開孔の形成とを同時に行う場合には、製造装置を簡素化でき、また生産性が向上し製造経費を低減できるという利点がある。また、得られる伸縮性シートの性能面からも、エラストマーフィルムに与えるダメージが少なく、良好な伸縮性のシートが得られることや破断が生じにくいという利点があるので好ましい。
【００４３】
【実施例】
エラストマー樹脂として、エチレン系エラストマー（ＳＥＢＳ）であるＧ１６５７（クレイトンポリマージャパン（株）製）用いた。不織布としてスパンボンド／メルトブローン／スパンボンド（ＳＭＳ）不織布（ランダムポリプロピレン、繊度１．５ｄｔｅｘ、坪量１５ｇ／ｍ²、構成比７／１／７ｇ／ｍ²）を用いた。径φ５０ｍｍの単軸押出機（Ｌ／Ｄ＝２８）と幅５００ｍｍのＴダイス（ダイリップクリアランス１．５ｍｍ）とからなるＴダイラミネート成形装置を用い、前記エラストマー樹脂を溶融押出し、その両面に前記不織布を重ね合わせて溶融ラミネート成形した。Ｔダイスの設定温度は２００℃、成形速度は１０ｍ／ｍｉｎ、ニップロール圧は０．３ＭＰａ、ニップクリアランスは０．５ｍｍであった。得られた複合シートは幅４００ｍｍであり、エラストマーフィルムの坪量は７０ｇ／ｍ²であった。複合シートにおける不織布とエラストマーフィルムとの間の剥離強度は１．５Ｎ／２５ｍｍであった。エラストマーフィルムの各種物性値は以下の通りであった。
・破断強度７．６Ｎ／２５ｍｍ
・破断伸度５９０％
・１００％伸長時強度２．９Ｎ／２５ｍｍ
・永久歪み４．０％
・１００％伸長時における初期変化率（行き）２．０％
・１００％伸長時における初期変化率（戻り）１．４％
【００４４】
次に図３に示す穿孔部を用いて複合シートの低伸縮領域に多数の開孔を形成した。穿孔ピンの半径は０．５ｍｍであり、温度は常温、かみ込み量は２ｍｍであった。このようにして得られた伸縮性シートの各種物性は以下の通りであった。
・破断強度１２．６Ｎ／２５ｍｍ
・破断伸度６２０％
・１００％伸長時強度３．０Ｎ／２５ｍｍ
・永久歪み５．０％
・１００％伸長時における初期変化率（行き）２．６％
・１００％伸長時における初期変化率（戻り）１．８％
【００４５】
【発明の効果】
以上詳述した通り、本発明の伸縮性複合シートの製造方法によれば、良好な風合い、高い伸縮性及び高い通気性を有する伸縮性不織布を、簡略な工程で、安価に製造することができる。本発明の製造方法によって得られる伸縮性複合シートは、不織布構造を維持しつつ大きな伸縮性を有する。従って、この伸縮性複合シートは、人の肌に直接触れる物品の構成材料、例えば使い捨ておむつのパネル部材、マスク、包帯などとして好適に使用される。
【図面の簡単な説明】
【図１】図１（ａ）は伸縮性複合シートが非伸張状態にある場合、図１（ｂ）は伸縮性複合シートが伸張状態にある場合の断面をそれぞれ示す模式図である。
【図２】伸縮性複合シートを製造するために好適な製造装置を示す模式図である。
【図３】図２に示す製造装置における穿孔部を拡大して示す模式図である。
【図４】図４（ａ）は図３に示す穿孔部によって複合シートが穿孔される様子を示す模式図であり、図４（ｂ）は図４（ａ）において穿孔部の装置を取り除いた状態を示す模式図である。
【符号の説明】
１ 伸縮性複合シート
２ エラストマーフィルム
３，４ 不織布
５ 高伸縮領域
６ 低伸縮領域
７ 開孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a stretchable composite sheet having good texture and high air permeability. The stretchable composite sheet obtained by the production method of the present invention is particularly suitably used as a panel member for disposable diapers.
[0002]
[Prior art and problems to be solved by the invention]
A composite nonwoven fabric having a stretchable three-layer structure is known (see Patent Document 1). This composite nonwoven fabric is constituted by laminating an inelastic layer made of polyethylene terephthalate fiber on both sides of an elastic layer made of polyurethane fiber. This composite nonwoven fabric is obtained by laminating a polyurethane fiber web on a polyethylene terephthalate fiber web, further laminating a polyethylene terephthalate fiber web thereon, and then heat embossing the laminate to make a nonwoven fabric. By stretching the wire in the width direction and returning it, looping, bulking, and punching of polyethylene terephthalate fiber, which is an inelastic fiber, are caused to exhibit stretchability. The composite nonwoven fabric obtained by this method exhibits good performance in terms of stretchability and air permeability. However, a sheet made of polyurethane fiber as an elastic layer is very expensive. In addition, the processing steps are complicated and the manufacturing cost is increased. Therefore, it is not economical to apply this composite nonwoven fabric to a disposable article such as a disposable diaper.
[0003]
After an elastic precursor is formed by intermittently bonding a substrate having low extensibility to an elastic member or mesh-like elastic member having no opening, the tension applied after the elastic precursor is stretched to a desired degree is relaxed. An elastic composite obtained by the above and a method for producing the same are also known (see Patent Document 2). The elastic composite obtained by this method has a problem of air permeability when an elastic member having no opening is used. In the case of using a mesh-like elastic member, this mesh-like elastic member is very expensive, and the processing process becomes complicated and the manufacturing cost becomes high, so that it can be applied to a disposable article such as a disposable diaper. Not economical.
[0004]
A roll having a three-dimensional surface and meshing with each other of a stretch-free web having a three-dimensional surface composed of a substantially non-tensioned first elastomer ply and a substantially non-tensioned second ply having a smaller elastic recovery than the first ply. There are known methods and apparatuses for removing elasticity from a web after applying a gradual stretching with a pressurizing apparatus having a pressure to give elasticity (see Patent Documents 3 to 5). The elastic web obtained by this method requires a complicated process such as supplying an elastomer ply previously opened or having an opening process again after being stretched in order to have air permeability. . Therefore, the manufacturing cost is increased.
[0005]
An elastic fiber nonwoven laminate in which a nonwoven surface layer in which a plurality of slits are formed in an elastic base layer is bonded and a method for forming the same are also known (see Patent Document 6). In order to give air permeability to the laminate obtained in this way, it is necessary to select a nonwoven fabric and a woven fabric as the elastic base layer, or select a film in which holes are perforated. Since these sheets are very expensive, it is not economical to apply them to disposable articles such as disposable diapers.
[0006]
Accordingly, an object of the present invention is to provide a method for producing an elastic nonwoven fabric having a good texture, high elasticity and high air permeability at a low cost by a simple process.
[0007]
[Patent Document 1]
JP-A-52-21479
[Patent Document 2]
Japanese Patent Publication No.8-30281
[Patent Document 3]
Japanese National Patent Publication No. 6-505408
[Patent Document 4]
JP-T 6-505446
[Patent Document 5]
Japanese translation of PCT publication No. 6-505681
[Patent Document 6]
JP 9-512504 gazette
[0008]
[Means for Solving the Problems]
In the present invention, a composite sheet is obtained by laminating an elastomer film on a nonwoven fabric by a melt laminating method, and then a receiving member in which a large number of grooves are arranged in multiple rows, and a perforated pin capable of entering the grooves Interposing the composite sheet between both members in a perforating apparatus provided with perforating members arranged in multiple rows at positions corresponding to the grooves, and further allowing the perforating pins to enter the grooves, By providing a method for producing a stretchable composite sheet that perforates a composite sheet to form a large number of apertures arranged in multiple rows, and at the same time, stretches the nonwoven fabric at positions between the rows of apertures to plastically deform The object has been achieved.
[0009]
  The present invention is a stretchable composite sheet formed by laminating an elastomer film and a nonwoven fabric,
  The sheet has a high stretch region and a low stretch region that extend in one direction, and both the regions are alternately arranged in multiple rows, and the sheet can be stretched in a direction perpendicular to the row direction of these regions. And
  The non-woven fabric is in the high stretch regionCan be stretched,In the low stretch region, substantiallyEven if it does not expand or contract, the degree of expansion or contraction is lower than the high expansion and contraction region,
  In the low stretchable region, a stretchable composite sheet is provided in which a large number of holes are formed at predetermined intervals along the length direction of the low stretchable region.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below based on preferred embodiments with reference to the drawings. 1 (a) and 1 (b) are schematic views showing examples of the elastic sheet 1 obtained by the method for producing the elastic composite sheet of the present invention (hereinafter also simply referred to as “elastic sheet”). Has been. FIG. 1A shows a case where the stretchable sheet 1 is in an unstretched state, and FIG. 1B shows a case where the stretchable sheet 1 is in a stretched state.
[0011]
The elastic sheet 1 is a single sheet having a three-layer structure in which the same or different kinds of nonwoven fabrics 3 and 4 are laminated and integrated on each surface of the elastomer film 2. The elastomer film 2 and the nonwoven fabrics 3 and 4 are bonded to each other on their entire surfaces. The stretchable sheet 1 has a high stretchable region 5 and a low stretchable region 6 extending in one direction. In FIGS. 1A and 1B, both regions extend in a direction perpendicular to the paper surface. Both regions are arranged alternately and in multiple rows within the surface of the stretchable sheet 1.
[0012]
The high stretchable region 5 is a main region for the stretchable sheet 1 to exhibit stretchability. The elastomer film 2 in the high stretch region 5 can be stretched. On the other hand, the nonwoven fabrics 3 and 4 can all be extended. Specifically, the elastomer film 2 in the high stretch region 5 is elastically deformable. On the other hand, the nonwoven fabrics 3 and 4 in the high expansion / contraction region 5 are partly broken in the nonwoven fabric structure, and are slightly fuzzy and can be plastically deformed. As a result, when the high stretchable region 5 is viewed as a whole, the region 5 can be stretched.
[0013]
On the other hand, the low stretchable region 6 is a region that is less stretchable than the high stretchable region 5, or is a region that does not substantially stretch, that is, a non-stretchable region. In the low expansion / contraction region 6, the nonwoven fabrics 3 and 4 maintain the nonwoven fabric structure, have less fuzz and are not substantially plastically deformed. In FIGS. 1 (a) and 1 (b), in order to emphasize the difference in fluffing of the nonwoven fabrics 3 and 4 in the high stretch region 5 and the low stretch region 6, there is a large difference in the thickness of the nonwoven fabrics 3 and 4. In practice, however, there is no such difference in the thicknesses of the nonwoven fabrics 3 and 4 in both regions 5 and 6. Due to the fact that the nonwoven fabrics 3 and 4 are not substantially plastically deformed, the elastic stretch of the elastomer film 2 in the low stretch region 6 is restricted. As a result, in the entire low expansion / contraction region 6, even if the region 6 does not substantially expand / contract, the extent of expansion / contraction is much lower than that of the high expansion / contraction region.
[0014]
Since the high stretchable regions 5 and the low stretchable regions 6 are arranged alternately and in multiple rows, the stretchable sheet 1 can be stretched in a direction perpendicular to the row direction of these regions. However, these regions do not substantially expand and contract in the column direction. That is, the stretchable sheet 1 has anisotropy in the stretch direction. As a result, when a product is manufactured using the stretchable sheet 1 as a material, if the stretchable sheet 1 is conveyed in parallel with the row direction of both regions 5 and 6 in the production line, the stretchable sheet 1 is caused to stretch. Can be effectively prevented.
[0015]
A large number of apertures 7 are formed in the low stretchable region 6 at predetermined intervals along the length direction of the low stretchable region 6. Since the low expansion / contraction regions 6 are arranged in multiple rows as described above, the apertures 7 are also arranged in multiple rows. As shown to Fig.1 (a), the opening 7 is not substantially open when the elastic sheet 1 is a non-expanded state. However, as shown in FIG. 1 (b), the stretchable sheet 1 opens when it is stretched. A method of forming such an opening 7 will be described later. The size of the opening 7 varies depending on the degree of expansion of the stretchable sheet 1. Generally, when the elastic sheet 1 is stretched to its maximum elongation, 0.01 to 100 mm², Especially 0.1-50mm²It is preferable to form the opening 7 so that the opening 7 having a certain area is formed.
[0016]
In the stretchable sheet 1 of the present embodiment having the above configuration, since the nonwoven fabrics 3 and 4 in the low stretchable region 6 maintain the nonwoven fabric structure, the stretchable sheet 1 as a whole has a good cloth-like texture. Presents. There is no excessive fuzz. On the other hand, in the high stretch region 5, the elastomer film 2 can be stretched and all of the nonwoven fabrics 3 and 4 can be stretched, so that the stretchable sheet 1 as a whole exhibits sufficient stretchability. . Thus, in the elastic sheet 1 of this embodiment, the cloth-like good texture of a nonwoven fabric and sufficient elastic property are balanced. Further, the stretchable sheet 1 of the present embodiment has a large opening 7 in the stretched state, and air can be circulated through the opening 7. That is, the stretchable sheet 1 exhibits sufficient air permeability. Further, since the stretchable sheet 1 is not substantially opened in the non-stretched state, there is an advantage that the degree of breathability can be adjusted according to the stretched degree of the stretchable sheet 1. Therefore, the elastic sheet 1 of the present embodiment is suitably used as a constituent member such as a side panel member, a mask, or a bandage of a disposable diaper.
[0017]
From the viewpoint of balancing the good texture and appearance of the nonwoven fabric-like fabric with sufficient stretchability and extensibility, the area of the high stretch region 5 in the non-stretched state is 5 to 50% of the total stretchable sheet 1 area. In particular, 5 to 20% is preferable. On the other hand, the area of the low stretchable region 6 is preferably 50 to 95%, particularly 80 to 95% of the total stretchable sheet 1 area. Further, although depending on the specific application of the stretchable sheet 1, the width of the high stretchable region 5 is preferably 0.5 to 20 mm, particularly preferably 1 to 10 mm. On the other hand, the width of the low stretchable region 6 is preferably 0.1 to 10 mm, particularly preferably 0.3 to 5 mm.
[0018]
As the elastomer film 2, for example, a polyethylene polymerized according to a known polymerization method using a known metallocene catalyst (the polyethylene has a density of 0.90 g / cm^ThreeIt is preferable that the comonomer is an α-olefin having 3 or more carbon atoms such as butene, hexene, octene, and the content thereof is preferably 10 mol% or more, more preferably 20 to 60 mol%); styrene Styrene elastomers such as isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-ethylene-butadiene-styrene (SEBS), and styrene-ethylene-propylene-styrene (SEPS); have urethane bond in hard segment Urethane elastomers that have polyether, polyester, caprolactone, polycarbonate, etc. in the soft segment; ester elastomers that have ester bonds in the hard segment and polyester, polyether, etc. in the soft segment It can be used. In addition, an elastomer film having moisture permeability can be used as the elastomer film 2. In that case, the breathability of the stretchable sheet 1 can be further improved.
[0019]
The basis weight of the elastomer film 2 is 5 to 150 g / m.², Especially 10-100g / m²It is preferable from the viewpoint of stretchability and strength. The elastomer film 2 preferably has a breaking elongation of 300% or more, particularly 500% or more from the viewpoint that sufficient stretchability is imparted to the stretchable sheet 1. The breaking strength of the elastomer film 2 is 3N or more, preferably 5N or more, the workability when plastically deforming the composite sheet, and for example, when the elastic sheet 1 is used as a constituent member of an absorbent article It is preferable from the viewpoint of preventing the elastic sheet 1 from being broken. The elastomer film 2 has a strength at the time of 100% elongation of 0.5 to 10 N / 25 mm, particularly 1 to 5 N / 25 mm from the point that sufficient stretchability and easy stretchability can be obtained for the elastic sheet 1. preferable. In addition, the elastomer film 2 has a permanent distortion of 30% or less, particularly 15% or less when the stress is released after stretching 100% in the stretching direction, and gives the stretchable sheet 1 good stretchability. It is preferable from the point that the fitting property of an article is obtained.
[0020]
The breaking strength, breaking elongation and 100% elongation strength of the elastomer film 2 are measured by the following methods, respectively. A sample having a width of 25 mm is prepared, and the sample is fixed to an extension tester without tension so that the distance between chucks is 50 mm. The sample is then stretched at a speed of 300 mm / min. The strength and elongation at the time when the sample broke was measured, and this was taken as the breaking strength and breaking elongation. Further, the strength at 100% elongation is measured, and this is defined as the strength at 100% elongation. The permanent set of the elastomer film 2 is measured by the following method. The operation up to 100% elongation of the sample is the same as the measurement of the breaking strength and the like described above. Next, the sample is returned to the initial chuck distance at a speed of 300 m / min. The amount of elongation at the time of no load is measured, and this is set as permanent strain.
[0021]
Furthermore, in the hysteresis of the stress-strain curve of the elastomer film 2, the initial rate of change (going) when the elastomer film 2 is stretched to 100% is 5% or less, particularly 3% or less. From the viewpoint of sex. For the same reason, it is preferable that the initial rate of change (return) when the elastomer film 2 is extended to 100% from the stretched state is returned to 7% or less, particularly 5% or less. The initial change rate (going) and the initial change rate (returning) are measured by the following method. A sample having a width of 25 mm is prepared, and the sample is fixed to an extension tester without tension so that the distance between chucks is 50 mm. Next, the sample is stretched 100% at a speed of 300 m / min (going). Subsequently, the distance is returned to the initial chuck distance at a speed of 300 m / min. The stress during this time is measured. The initial change rate (going) and the initial change rate (return) are calculated from the following equations.
[0022]
[Expression 1]

[0023]
As the nonwoven fabric, a known nonwoven fabric such as an air-through nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, a melt blown nonwoven fabric, or a composite nonwoven fabric thereof (for example, a spunbond / meltblown / spunbond nonwoven fabric) can be used. The fibers constituting the nonwoven fabric include polyolefin fibers made of polyolefin such as polyethylene and polypropylene; polyester fibers made of polyester such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as 6 nylon, 6, 6 nylon and 12 nylon. Polyamide-based fibers made of the above, or core-sheath type or side-by-side type fibers made of the above resin are used. These may be used alone or in combination of two or more. The fineness of these fibers is preferably 1 to 10 denier. Of the above-mentioned nonwoven fabrics, it is preferable to use a spunbonded nonwoven fabric or a spunbonded / meltblown / spunbonded nonwoven fabric because it is particularly stretchable, has less fuzz, and is easy to process, particularly plastic deformation. The two nonwoven fabrics 3 and 4 may be the same or different as described above. Each nonwoven fabric has a basis weight of 5 to 100 g / m.², Especially 10-50g / m²It is preferable in terms of texture, touch, firmness and strength.
[0024]
The basis weight of the elastic sheet 1 as a whole is 15 to 350 g / m.², Especially 30-200g / m²It is preferable from the viewpoint of texture, touch, firmness and sheet strength.
[0025]
The stretchable sheet 1 preferably has extensibility such that the elongation at break in the stretch direction is 300% or more, particularly 500% or more. The stretchable sheet 1 preferably has a breaking strength of 5N or more, particularly 10N or more from the viewpoint of preventing breakage when the stretchable sheet 1 is used as a constituent member of an absorbent article, for example. The stretch sheet 1 has a strength at 100% elongation of 0.5 to 10 N / 25 mm, particularly 1 to 5 N / 25 mm, and the stretchability of the stretchable sheet 1 is sufficient. To preferred. The stretchable sheet 1 has a permanent distortion after stretching 100% in the stretch direction of 30% or less, particularly 15% or less, when the stretchable sheet 1 is used as a constituent member of an absorbent article, for example. It is preferable from the point that the fitting property of an absorbent article becomes favorable. The stretchable sheet 1 has a stress-strain curve hysteresis with an initial change rate (going) of 5% or less, particularly 3% or less when the stretchable sheet 1 is stretched to 100%. From the viewpoint of shrinkage. For the same reason and when the stretchable sheet 1 is used as a constituent member of an absorbent article, for example, the stretchability of the stretchable sheet 1 up to 100% is improved from the point that the absorbent article has good fit. The initial rate of change (return) when returning to the state is preferably 7% or less, particularly preferably 5% or less. In order to develop such stretchability, for example, i) using an elastomer film 2 having suitable stretchability, ii) adjusting the area ratio between the high stretch region 5 and the low stretch region 6, iii) The widths of the high stretch region 5 and the low stretch region 6 may be adjusted.
[0026]
The breaking strength, breaking elongation, 100% elongation strength, initial rate of change (going) and initial rate of change (return) of the elastic sheet 1 are measured by the same methods as those for the elastomer sheet 2.
[0027]
Next, the suitable manufacturing method of the elastic sheet 1 of this embodiment is demonstrated. FIG. 2 shows a schematic diagram of a production apparatus suitable for producing the stretchable sheet 1. The manufacturing apparatus 10 shown in FIG. 2 is roughly divided into a laminated portion 20 of an elastomer film and a nonwoven fabric, a perforated portion 30 of a composite sheet obtained by lamination, and a winding portion 40 of a stretchable sheet obtained by perforating. . The stacked unit 20 includes a pair of nip rolls 21 and 21. The elastomer film and the nonwoven fabric pass between the nip rolls 21 and 21 and are pressed. The perforated part 30 includes a pair of roll members 31 and 32. The winding unit 40 includes a winder 41 made of a stretchable sheet.
[0028]
The nip rolls 21 and 21 are generally composed of a combination of a metal cooling roll and a rubber roll. The surface of the cooling roll has a mirror surface, a satin finish, a dot pattern, etc., and can be used properly according to the purpose. The rubber roll is selected from natural rubber, isoprene rubber, butadiene rubber, styrene / butadiene rubber, ethylene / propylene rubber, nitrile rubber, urethane rubber, silicone rubber, and the like. The hardness ranges from A hardness 50 to D hardness 95 depending on the purpose. A clearance adjustment mechanism (not shown) may be attached between the nip rolls 21 and 21 to adjust the nip pressure.
[0029]
An enlarged view of the perforated part 30 is shown in FIG. One roll member 31 constituting the perforated portion 30 is composed of a receiving roll in which a number of grooves 33, 33,... Are arranged in multiple rows along the circumferential direction of the roll. On the other hand, the other roll member 32 is composed of a perforated roll in which perforated 34 pins that can enter a groove 33 formed in the receiving roll 31 are arranged at positions corresponding to the groove 33. The perforating pins 34 are arranged in multiple rows at predetermined intervals along the circumferential direction of the roll. The piercing pin 34 has a pointed tip, and is easy to penetrate the sheet. The piercing pin 34 has a circular cross section. The radius is about 0.1 to 10 mm. The perforating roll 32 is provided with a heating means, and the perforating pins 34 can be heated by the heating means. Depending on the material of the sheet, the perforation pin 34 may not be heated. Although the temperature of the perforated pin 34 depends on the constituent resin of the elastomer film and the nonwoven fabric, it is generally preferably 10 to 100 ° C., particularly 10 to 80 ° C., in relation to the melting point of the constituent resin. The piercing pin 34 has a flange (not shown) slightly narrower than the width of the groove 33 in the vicinity of its tip. That is, the flange extends in a direction (horizontal direction) perpendicular to the height direction of the piercing pin 34 at a position slightly below the tip of the piercing pin 34. Details of the buttocks will be described later.
[0030]
The manufacturing method of the stretchable sheet 1 using the manufacturing apparatus 10 having the above configuration will be described. First, the elastomer film 2 formed by being melt-extruded from the T die 23 is unsolidified on each surface thereof. Nonwoven fabrics 3 and 4 are laminated and laminated and integrated by a melt laminating method sandwiched between nip rolls 21 and 21, respectively. Each nonwoven fabric 3 and 4 is manufactured separately from the elastomer film. In the melt laminating method, the elastomer is melted at a temperature equal to or higher than its melting point by an extruder or the like, extruded from the T-die 23, and then naturally cooled to the environmental temperature. In this cooling process, the unsolidified elastomer film is sandwiched between the nonwoven fabric and the nip rolls 21 and 21. The temperature of the cooling roll in the nip roll is preferably set to 0 to 50 ° C. In order to adjust the adhesive force between the elastomer film and the nonwoven fabric, the nip pressure is preferably 0.1 to 1 MPa. The clearance amount of the nip roll varies depending on the nonwoven fabric to be used, but is preferably 0 to 1.5 mm.
[0031]
By using the melt laminating method for joining the elastomer film and the nonwoven fabric, there is an advantage that the manufacturing process can be simplified as compared with other joining methods such as joining using an adhesive. In addition, there is an advantage that productivity is good and manufacturing cost is low.
[0032]
The composite sheet 1 ′ is melt-laminated so that the width direction (CD) peel strength between the elastomer film and the nonwoven fabric is 0.5 to 5 N / 25 mm. This is preferable from the viewpoint of preventing fuzz. The peel strength is measured by the following method. A strip-shaped sample having a width of 25 mm is prepared. At one end in the longitudinal direction of this sample, the joint surface between the elastomer film and the nonwoven fabric is peeled off by hand. The peeled elastomer film and non-woven fabric are fixed to an elongation tester without tension so that the distance between chucks is 50 mm. Next, the sample is pulled at a speed of 300 mm / min, and the joint surface between the elastomer film and the nonwoven fabric is peeled off. The intensity at that time is measured, and an average value of a total of 6 points including 3 points from the highest maximum value and 3 points from the lowest minimum value is calculated. This value is defined as peel strength.
[0033]
The obtained composite sheet 1 ′ is then interposed between the receiving roll 31 and the punching roll 32 in the punching unit 30. Each roll 31 and 32 is rotating in the direction shown by the arrow in FIG. By this rotation, the piercing pin 34 attached to the piercing roll 32 passes through the composite sheet 1 ′ and enters the groove 33 located at a position corresponding to the piercing pin 34. This state is shown in FIG.
[0034]
As shown in FIG. 4A, when the piercing pin 34 penetrates the composite sheet 1 ′, the piercing pin 34 excessively penetrates the composite sheet 1 ′ by the flange 35 provided near the tip of the piercing pin 34. Is suppressed. At the same time, the surface of the piercing portion 35 on the tip end side of the piercing pin presses the composite sheet 1 ′ located at and near the entry position of the piercing pin 34. By these actions, the nonwoven fabric located at the entrance position of the perforation pin 34 and the vicinity thereof is restricted from being substantially plastically deformed, and only the composite sheet 1 'is perforated.
[0035]
On the other hand, the composite sheet 1 ′ is stretched between the grooves 33 by the penetration of the piercing pins 34 and the pressing of the surface of the piercing pins 34. As a result, the elastomer film in the composite sheet 1 'is elastically stretched, and both nonwoven fabrics are plastically deformed. Due to this plastic deformation, a part of the nonwoven fabric structure of each nonwoven fabric is destroyed, and fluffing occurs before the deformation. This state is shown in FIG. FIG. 4B corresponds to a state in which the receiving roll 31 and the punching roll 32 are removed in FIG. As is clear from FIG. 4B, in the composite sheet 1 ′, the region located between the grooves 33 and 33 is extended, and the composite sheet 1 is located in the vicinity of the entry position of the perforation pin 34 and the vicinity thereof. The sheet 1 ′ is not substantially stretched and almost maintains the state before being punched. An opening 7 is formed in a region that is not stretched. The stretched regions and the substantially non-stretched regions are alternately extended along the conveyance direction of the composite sheet 1 ′. The stretched region becomes the high stretchable region 5 in the stretchable sheet 1 finally obtained. On the other hand, the region that is not substantially stretched becomes the low stretchable region 6 in the stretchable sheet 1 that is finally obtained. As described above, in the present embodiment, the composite sheet 1 'is perforated without making the nonwoven fabric existing at the entrance position of the perforation pin 34 and its vicinity substantially plastically deformed, and a large number of openings arranged in multiple rows are formed. Simultaneously with the formation, the nonwoven fabric at the position between the rows of the apertures is stretched and plastically deformed.
[0036]
The area of the opening by the piercing pins 34 and the amount of plastic deformation of the nonwoven fabric in the high stretchable region 5 greatly depend on the amount of the piercing roll 32 biting into the receiving roll 31. The amount of biting is preferably 0.5 to 10 mm, particularly 1 to 5 mm from the viewpoint of the stretchability of the stretchable sheet 1 to be obtained. As the rotation of both rolls 31 and 32 proceeds, the perforation pins 34 that have entered the composite sheet 1 'are pulled out from the composite sheet 1'. As a result, the opening 7 is closed or substantially not opened by the elastic contraction action of the elastomer film.
[0037]
In this way, the composite sheet 1 ′ passes through the perforated part 30, so that the opening 7 is formed, and at the same time, the low stretch region 6 and the high stretch region 5 are formed, and the stretchable sheet 1 is obtained. The stretchable sheet 1 is wound up by a winder 41 in a winding unit 40.
[0038]
The present invention is not limited to the embodiment. For example, although the stretchable sheet of the above embodiment has a three-layer structure, a two-layer structure made of an elastomer film and a nonwoven fabric may be used instead. Alternatively, a multilayer structure having four or more layers may be used.
[0039]
Moreover, although the melt lamination method was used in the said embodiment as a joining means of an elastomer film and a nonwoven fabric, you may use together the adhesion | attachment by an adhesive agent to this. Examples of the adhesive coating method include a slot spray method, a curtain spray method, a spiral spray method, a melt blown method, a bead method, a gravure method, and a coater method. Types of adhesives include styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), and mixtures thereof, so-called rubber-based, polyolefin-based, ethylene-vinyl acetate-based, polyamide-based, polyester There are things of the system. The coating amount is 0.3 to 10 g / m from the viewpoint of obtaining the peel strength described above.²It is preferable that
[0040]
Moreover, in the said embodiment, although the elastic sheet 1 was manufactured in a series of processes using the apparatus provided with the lamination | stacking part 20, the perforation | perforation part 30, and the winding-up part 40, it replaced with this and an elastic sheet was carried out in two different processes. 1 may be manufactured. For example, the elastomer sheet 2 and the nonwoven fabrics 3 and 4 are laminated and integrated by a melt laminating method to obtain a composite sheet 1 ', and after winding it once, the wound composite sheet 1' is manufactured as an absorbent article. It may be attached to the line, and then the composite sheet 1 ′ is drawn out to perform a perforating process to obtain the elastic sheet 1, which may be further incorporated into the absorbent article by in-run.
[0041]
In addition, after the composite sheet 1 'has been perforated, if a lot of fuzz occurs due to partial destruction of the nonwoven fabric structure or the peel strength between the nonwoven fabric and the elastomer film decreases, before, after, or before and after perforation Both are preferably embossed. The embossing is performed by, for example, a method of passing a sheet between any of a rubber roll, a metal roll, a paper roll, a cotton roll, and the like and a metal roll on which a pattern is carved. It is effective to perform embossing under heating. Various general emboss patterns are used. A dot pattern is preferably used in terms of not inhibiting the stretchability.
[0042]
In the above embodiment, the high stretch region and the low stretch region were formed at the same time as the formation of the opening in the low stretch region, but instead the high stretch region and the low stretch region were first formed, Thereafter, an opening in the low expansion / contraction region may be formed. However, when the formation of the high stretch region and the low stretch region and the formation of the opening in the low stretch region are performed at the same time, there is an advantage that the manufacturing apparatus can be simplified, the productivity can be improved, and the manufacturing cost can be reduced. is there. Also, from the viewpoint of the performance of the resulting stretchable sheet, there is little damage to the elastomer film, which is preferable because a favorable stretchable sheet can be obtained and breakage hardly occurs.
[0043]
【Example】
As the elastomer resin, G1657 (manufactured by Kraton Polymer Japan Co., Ltd.) which is an ethylene elastomer (SEBS) was used. Spunbond / meltblown / spunbond (SMS) nonwoven fabric (random polypropylene, fineness 1.5 dtex, basis weight 15 g / m as nonwoven fabric², Composition ratio 7/1 / 7g / m²) Was used. The elastomer resin is melt-extruded using a T-die laminating apparatus comprising a single-screw extruder (L / D = 28) having a diameter of 50 mm and a T-die having a width of 500 mm (die lip clearance 1.5 mm), and the nonwoven fabric is formed on both sides thereof. Were laminated by melt lamination. The set temperature of the T die was 200 ° C., the molding speed was 10 m / min, the nip roll pressure was 0.3 MPa, and the nip clearance was 0.5 mm. The obtained composite sheet has a width of 400 mm, and the basis weight of the elastomer film is 70 g / m.²Met. The peel strength between the nonwoven fabric and the elastomer film in the composite sheet was 1.5 N / 25 mm. Various physical property values of the elastomer film were as follows.
-Breaking strength: 7.6 N / 25 mm
・ Elongation at break 590%
・ Strength at 100% elongation 2.9 N / 25 mm
・ Permanent distortion 4.0%
-Initial rate of change at 100% elongation (bound) 2.0%
・ Initial rate of change at 100% elongation (return) 1.4%
[0044]
Next, a large number of apertures were formed in the low stretch region of the composite sheet using the perforated part shown in FIG. The radius of the punch pin was 0.5 mm, the temperature was room temperature, and the amount of biting was 2 mm. Various physical properties of the elastic sheet thus obtained were as follows.
・ Breaking strength 12.6N / 25mm
・ Elongation at break 620%
・ Strength at 100% elongation 3.0N / 25mm
・ Permanent distortion 5.0%
-Initial rate of change at 100% elongation (bound) 2.6%
-Initial rate of change at 100% elongation (return) 1.8%
[0045]
【The invention's effect】
As described above in detail, according to the method for producing a stretchable composite sheet of the present invention, a stretchable nonwoven fabric having a good texture, high stretchability and high breathability can be produced at a low cost by a simple process. . The stretchable composite sheet obtained by the production method of the present invention has a large stretchability while maintaining the nonwoven fabric structure. Therefore, this stretchable composite sheet is suitably used as a constituent material of an article that directly touches human skin, such as a panel member of a disposable diaper, a mask, or a bandage.
[Brief description of the drawings]
FIG. 1A is a schematic view showing a cross section when the stretchable composite sheet is in an unstretched state, and FIG. 1B is a schematic view showing a cross section when the stretchable composite sheet is in a stretched state.
FIG. 2 is a schematic view showing a production apparatus suitable for producing an elastic composite sheet.
3 is an enlarged schematic view showing a perforated portion in the manufacturing apparatus shown in FIG. 2. FIG.
4 (a) is a schematic view showing a state in which a composite sheet is perforated by the perforating part shown in FIG. 3, and FIG. 4 (b) is a diagram in which the perforating part device is removed from FIG. It is a schematic diagram which shows a state.
[Explanation of symbols]
1 Stretchable composite sheet
2 Elastomer film
3,4 Nonwoven fabric
5 High stretch area
6 Low stretch area
7 Opening

Claims (5)

  A composite sheet is obtained by laminating an elastomer film on a nonwoven fabric by a melt laminating method, and then a receiving member in which a large number of grooves are arranged in multiple rows, and perforated pins that can enter the grooves are formed in the grooves. The composite sheet is interposed between both members in a perforating apparatus provided with perforating members arranged in multiple rows at positions corresponding to the above, and the perforating pins are inserted into the grooves to perforate the composite sheet. A method for producing a stretchable composite sheet in which a large number of apertures arranged in multiple rows are formed, and at the same time, the nonwoven fabric is stretched and plastically deformed at positions between the rows of apertures.   The piercing pin has a pointed tip and has a flange slightly narrower than the width of the groove in the vicinity of the tip. And the manufacturing method of the elastic composite sheet of Claim 1 which controls the substantially plastic deformation of the said nonwoven fabric existing in the vicinity. An elastic composite sheet formed by laminating an elastomer film and a nonwoven fabric,
The sheet has a high stretch region and a low stretch region that extend in one direction, and both the regions are alternately arranged in multiple rows, and the sheet can be stretched in a direction perpendicular to the row direction of these regions. And
The non-woven fabric, the high in stretchable region is capable of expansion and contraction, the degree of even its expansion as in the low-stretch region either does not substantially stretch, or to stretch is lower than the high expansion area,
A stretchable composite sheet in which a large number of apertures are formed at predetermined intervals in the low stretchable region along the length direction of the low stretchable region.   The elastic composite sheet according to claim 3, wherein the nonwoven fabric is laminated on each surface of the elastomer film.   The opening is substantially not opened when the stretchable composite sheet is in an unstretched state, but is opened when the stretchable composite sheet is in a stretched state. The elastic composite sheet as described.

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