JP7089365B2

JP7089365B2 - Laminated film

Info

Publication number: JP7089365B2
Application number: JP2017253760A
Authority: JP
Inventors: 裕貴高田; 秀行小林
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2017-12-28
Filing date: 2017-12-28
Publication date: 2022-06-22
Anticipated expiration: 2037-12-28
Also published as: JP2019119068A

Description

本発明は積層フィルムに関する。 The present invention relates to a laminated film.

従来、生理用ナプキンなどの吸収性物品において、排泄液に対する防漏性の観点から特定のフィルムが用いられることがある。フィルムとしては、例えば無機フィラーを溶融混練して押し出したものなどが挙げられる。このフィルムに種々の機能を付与する技術がある。
例えば、特許文献１には、エラストマーコア層の両面に非弾性の表皮外側層を有する弾性フィルムラミネートが記載されている。この弾性フィルムラミネートは弾性領域と非弾性領域とを有し、弾性領域において、表皮層がエラストマー層から部分的に離層され、シャーリングされている。これにより、繰り返し伸縮させても長期間に亘って回復させることができるとされる。
特許文献２には、エラストマー性コア層を２つのスキン層で挟持した多層フィルムに、不織布等のウェブ層を積層して伸縮可能なウェブ積層体を作製する方法が記載されている。この作製方法において、加工中のネッキング等による製品の廃棄量を減らすため、多層フィルムを機械幅方向に活性化し、かつ、スキン層の限界を越えて機械方向に延伸し、機械方向に伸長させた多層フィルムにウェブ層を積層する処理を行っている。 Conventionally, in an absorbent article such as a menstrual napkin, a specific film may be used from the viewpoint of leakage resistance to excrement. Examples of the film include those obtained by melting and kneading an inorganic filler and extruding it. There is a technique for imparting various functions to this film.
For example, Patent Document 1 describes an elastic film laminate having an inelastic outer skin layer on both sides of an elastomer core layer. This elastic film laminate has an elastic region and a non-elastic region, and in the elastic region, the epidermis layer is partially separated from the elastomer layer and shirred. As a result, it is said that it can be recovered over a long period of time even if it is repeatedly expanded and contracted.
Patent Document 2 describes a method for producing a stretchable web laminate by laminating a web layer such as a non-woven fabric on a multilayer film in which an elastomeric core layer is sandwiched between two skin layers. In this manufacturing method, in order to reduce the amount of product waste due to necking during processing, the multilayer film was activated in the machine width direction, stretched in the machine direction beyond the limit of the skin layer, and stretched in the machine direction. A process of laminating a web layer on a multilayer film is performed.

特表平７－５０８４７３号公報Special Table No. 7-508473 Gazette 特表２０１５－５２９５８１号公報Japanese Patent Application Laid-Open No. 2015-528581

吸収性物品においてフィルムを用いる部材として、着衣側（非肌面側）の裏面シートが挙げられる。フィルムからなる裏面シートは、その触感が肌面側の表面シートをなす不織布とは対照的に柔らかさを感じ難く、無機質な印象になりやすい。例えば、温かみの無いツルツルした触感、パリパリした触感などになることである。裏面シートは吸収性物品の装着時に使用者の手に触れやすい部分であり、吸収性物品全体の使用者の印象を良くするため、できるだけ柔らかく、かつ温かみのある肌触りにすることが望まれる。例えば、裏面シートの非肌面側に不織布を配して触感を良くする方法がある。しかし、不織布を積層する分、厚みが増してしまい、装着時の快適性に改善の余地がある。 Examples of the member using the film in the absorbent article include a back sheet on the clothing side (non-skin surface side). The back sheet made of a film does not feel soft in contrast to the non-woven fabric that forms the front sheet on the skin side, and tends to give an inorganic impression. For example, it has a smooth and smooth feel without warmth, and a crisp feel. The back sheet is a part that is easily touched by the user when the absorbent article is attached, and in order to improve the impression of the user as a whole of the absorbent article, it is desired to make the back sheet as soft and warm as possible. For example, there is a method of arranging a non-woven fabric on the non-skin surface side of the back sheet to improve the tactile sensation. However, the thickness is increased by the amount of laminating the non-woven fabric, and there is room for improvement in the comfort at the time of wearing.

本発明は、上記の点に鑑み、不織布の積層を避けて、良好な外観を保ち、肌触りが良い布材様な触感を得られるフィルムを提供することに関する。 In view of the above points, the present invention relates to providing a film that avoids laminating a non-woven fabric, maintains a good appearance, and can obtain a cloth-like feel that is soft to the touch.

本発明は、弾性層と塑性層とを有し、前記塑性層を最表面とする積層構造のフィルムであって、該フィルムは、一方の面から他方の面に突出する積層構造の凸部を複数、離間して配した凹凸構造を有し、前記凸部は平面方向に互いに交差する複数方向に配列されている積層フィルムを提供する。 The present invention is a film having a laminated structure having an elastic layer and a plastic layer with the plastic layer as the outermost surface, and the film has a convex portion of the laminated structure protruding from one surface to the other. Provided is a laminated film having a plurality of concavo-convex structures arranged at intervals, and the convex portions are arranged in a plurality of directions intersecting each other in a plane direction.

本発明の積層フィルムは、良好な外観を保ち、肌触りが良い布材様な触感を呈することができる。 The laminated film of the present invention can maintain a good appearance and exhibit a cloth-like feel that is soft to the touch.

本発明に係る積層フィルムの好ましい実施形態を一部拡大して模式的に示す斜視図である。It is a perspective view which shows typically the preferable embodiment of the laminated film which concerns on this invention by enlarging a part. 本実施形態の積層フィルムを一部拡大して模式的に示す平面図である。It is a top view which shows schematically the laminated film of this embodiment by enlarging a part. 本実施形態の積層フィルムの凸部の配置と共に、凸部間の連結部が白色化された状態を示す図面代用写真である。（Ａ）は本実施形態の積層フィルムを図１におけるＸ方向から見た図面代用写真であり、（Ｂ）は本実施形態の積層フィルムを図１におけるＹ方向から見た図面代用写真である。It is a drawing-substituting photograph showing a state in which the connecting portion between the convex portions is whitened together with the arrangement of the convex portions of the laminated film of the present embodiment. (A) is a drawing-substituting photograph of the laminated film of the present embodiment viewed from the X direction in FIG. 1, and (B) is a drawing-substituting photograph of the laminated film of the present embodiment viewed from the Y direction of FIG. 起伏構造を模式的に示す一部拡大断面図である。It is a partially enlarged sectional view schematically showing an undulating structure. 積層フィルムにおいて、起伏構造を有する領域と有さない領域とが隣接して配されている状態を拡大して示す図面代用写真である。It is a drawing substitute photograph which shows the state in which the region having an undulating structure and the region not having an undulating structure are arranged adjacent to each other in the laminated film. 起伏構造を有する領域において、厚みが、起伏構造を有さない領域よりも薄くされた状態を模式的に示す断面図である。It is sectional drawing which shows typically the state which the thickness in the region which has an undulating structure is thinner than the region which does not have an undulating structure. （Ａ）は本発明の積層フィルムを製造する際に用いられる原料フィルムを模式的に示す断面図であり、（Ｂ）は原料フィルムに対し部分延伸する工程を模式的に示す説明図である。(A) is a cross-sectional view schematically showing a raw material film used in manufacturing the laminated film of the present invention, and (B) is an explanatory view schematically showing a step of partially stretching a raw material film. 図８に示す部分延伸工程を施すことによって、原料フィルムに起伏構造が形成される過程を示す説明図であり、（Ａ）は部分延伸する前の原料フィルムの断面図であり、（Ｂ）は（Ａ）の原料フィルムを延伸している状態を示す断面図であり、（Ｃ）は（Ｂ）の延伸の後に、弾性層が弾性回復して起伏構造が形成される状態を示す断面図である。It is explanatory drawing which shows the process which the undulating structure is formed in the raw material film by performing the partial stretching step shown in FIG. 8, (A) is the sectional view of the raw material film before partial stretching, (B) is (A) is a cross-sectional view showing a state in which the raw material film is stretched, and (C) is a cross-sectional view showing a state in which the elastic layer is elastically restored to form an undulating structure after the stretching of (B). be.

以下、本発明の積層フィルムについて、その好ましい実施形態に基づき図面を参照して説明する。 Hereinafter, the laminated film of the present invention will be described with reference to the drawings based on the preferred embodiment thereof.

図１は、本実施形態の積層フィルム１０を示している。積層フィルム１０は、弾性層１と塑性層２とを有し、塑性層２を積層フィルム１０の最表面としている。本実施形態の積層フィルム１０は、弾性層１の両面に一対の塑性層２を積層した３層構造を有する。ただし、本発明においては、この３層構造に限定されるものではなく、最表面が塑性層２からなる種々の積層構造とすることができる。積層フィルム１０は、吸収性物品における非肌面側の裏面シート等に用いる場合において、防漏性を有することが好ましい。また、積層フィルム１０は適度な透湿性を有することが好ましい。 FIG. 1 shows the laminated film 10 of the present embodiment. The laminated film 10 has an elastic layer 1 and a plastic layer 2, and the plastic layer 2 is the outermost surface of the laminated film 10. The laminated film 10 of the present embodiment has a three-layer structure in which a pair of plastic layers 2 are laminated on both surfaces of the elastic layer 1. However, the present invention is not limited to this three-layer structure, and various laminated structures in which the outermost surface is composed of the plastic layer 2 can be used. The laminated film 10 is preferably leak-proof when used for a back surface sheet or the like on the non-skin surface side of an absorbent article. Further, it is preferable that the laminated film 10 has an appropriate moisture permeability.

ここで「弾性層」とは、伸長させることができ、かつ伸長のために付加した引張り力を解除したときに収縮するエラストマー性を有する層である。具体的には、「弾性層」とは、少なくとも一方向の最大伸度が４００％（元のシート長からその３００％分伸長した状態＝元のシート長の３倍）以上であり、その最大伸度の方向に伸度５０％まで伸長させた後に収縮させたときの伸長回復率（５０％伸長時の伸長回復率）が少なくとも５０％以上であることを意味する。最大伸度が４００％以上である方向を複数有する弾性層である場合、そのうちの何れかの方向において伸長回復率が５０％以上であればよい。このような「弾性層」としては、上記エラストマー性を有し、薄い層に形成することが可能な種々の材料から形成することができる。例えばポリマー樹脂成分からなるものとすることができる。具体的には、熱可塑性エラストマー、ゴム、エチレン・プロピレン共重合体等が挙げられ、これらの中でも、比較的容易に繊維状の弾性体が成形できる点から、熱可塑性エラストマーが好ましい。熱可塑性エラストマーとしては、ポリウレタン、スチレン系（ＳＢＳ，ＳＩＳ，ＳＥＢＳ，ＳＥＰＳ等）、オレフィン系（エチレン、プロピレン、ブテン等の共重合体等）、塩化ビニル系、ポリエステル系等を挙げることができる。これらは１種を単独で又は２種以上を組み合わせて用いることができる。 Here, the "elastic layer" is a layer having an elastomeric property that can be elongated and contracts when the tensile force applied for elongation is released. Specifically, the "elastic layer" has a maximum elongation of at least 400% in one direction (a state in which the original sheet length is extended by 300% = 3 times the original sheet length), and the maximum is the maximum. It means that the elongation recovery rate (elongation recovery rate at the time of 50% elongation) when the elongation is extended to 50% in the elongation direction and then contracted is at least 50% or more. When the elastic layer has a plurality of directions in which the maximum elongation is 400% or more, the elongation recovery rate may be 50% or more in any of the directions. Such an "elastic layer" can be formed from various materials having the above-mentioned elastomeric property and which can be formed into a thin layer. For example, it can be composed of a polymer resin component. Specific examples thereof include thermoplastic elastomers, rubbers, ethylene / propylene copolymers, and the like. Among these, thermoplastic elastomers are preferable because a fibrous elastic body can be formed relatively easily. Examples of the thermoplastic elastomer include polyurethane, styrene-based (SBS, SIS, SEBS, SEPS, etc.), olefin-based (copolymers such as ethylene, propylene, butene, etc.), vinyl chloride-based, polyester-based, and the like. These can be used alone or in combination of two or more.

＜伸長回復率の測定方法＞
長さ５０ｍｍ、幅２５ｍｍのサンプル片を用意し、引っ張り試験機（株式会社オリエンテックの「テンシロン」ＲＴＣ－１２１０Ａ）を用いて、チャック間隔Ｋ０にサンプル片を固定し、３００ｍｍ／ｍｉｎの速度で５０％伸長時の長さＫ２（Ｋ２＝Ｋ０×１．５）まで伸長させた後、引張速度と同様の速度で戻し始めて応力が０になった時におけるサンプル片の長さを伸長回復後の長さＫ１とする。次式から５０％伸長時の伸長回復率を算出する。
５０％伸長時の伸長回復率（％）＝〔（Ｋ２－Ｋ１）／（Ｋ２－Ｋ０）〕×１００ <Measurement method of elongation recovery rate>
Prepare a sample piece with a length of 50 mm and a width of 25 mm, fix the sample piece at a chuck interval of K0 using a tensile tester (Orientec Co., Ltd. "Tencilon" RTC-1210A), and 50 at a speed of 300 mm / min. % Length at the time of elongation After stretching to K2 (K2 = K0 × 1.5), the length of the sample piece when the stress becomes 0 by starting to return at the same speed as the tensile speed is the length after the elongation recovery. Let's call it K1. The elongation recovery rate at the time of 50% elongation is calculated from the following equation.
Elongation recovery rate at 50% elongation (%) = [(K2-K1) / (K2-K0)] × 100

「塑性層」とは、弾性層よりも低いエラストマー性を有する層である。具体的には、「塑性層」とは、前記＜伸長回復率の測定方法＞により測定した伸長回復率が５０％以下の層または５０％伸長する前に破断する層をいう。塑性層は、伸長性を有していても有していなくてもよいが、部分延伸時に塑性層が破断しないようにするために、最大伸度１００％以上であることが好ましい。このような「塑性層」としては、弾性層よりも低いエラストマー性を有し、薄い層に形成することが可能な種々の材料から形成することができる。例えば半結晶性又は非結晶性ポリマー樹脂成分からなるものとすることができる。具体的には、オレフィン系、アミド系、エステル系、アクリルコポリマー系、またこれらの組み合わせなどが挙げられる。 The "plastic layer" is a layer having a lower elastomeric property than the elastic layer. Specifically, the "plastic layer" refers to a layer having an elongation recovery rate of 50% or less measured by the above <method for measuring elongation recovery rate> or a layer that breaks before being elongated by 50%. The plastic layer may or may not have extensibility, but it is preferably 100% or more in maximum elongation in order to prevent the plastic layer from breaking during partial stretching. Such a "plastic layer" can be formed from various materials that have lower elastomeric properties than the elastic layer and can be formed into a thin layer. For example, it may consist of a semi-crystalline or amorphous polymer resin component. Specific examples thereof include olefin-based, amide-based, ester-based, acrylic copolymer-based, and combinations thereof.

また、顔料、酸化防止剤、帯電防止材、結合助剤、充填材、ブロッキング防止剤、スリップ材、熱安定剤、光安定剤、発泡剤、強化繊維のような添加剤を、塑性層や弾性層に使用してもよい。 In addition, additives such as pigments, antioxidants, antistatic materials, binding aids, fillers, anti-blocking agents, slip materials, heat stabilizers, light stabilizers, foaming agents, and reinforcing fibers can be added to the plastic layer and elasticity. May be used for layers.

＜市販のナプキン等からフィルムを取り出し・解析する手段＞
市販のナプキン等からフィルムを取り出す場合は、コールドスプレーで各材料間を接着するホットメルトを固化させ、フィルムを丁寧に剥がす。
剥がしたフィルムは、液体窒素に浸漬させて、取り出してすぐに厚み方向にカッター刃を使って切断する。切断したフィルムは、切断面が上になるように走査型電子顕微鏡（ＳＥＭ）用観察台に設置し、倍率７００倍で切断面を観察することで、層構造になっていることを確認できる。
層構造になっていたフィルムは、長さ１０ｃｍ四方に切り出し、弾性層もしくは塑性層のどちらかのみ溶かすことができる溶媒に浸漬させることで、弾性層、塑性層をそれぞれ取り出す。そのため、弾性層を取り出す場合は、塑性層のみが溶ける溶媒にフィルムを浸漬させる。塑性層を取り出す場合は、弾性層のみが溶ける溶媒にフィルムを浸漬させる。 <Means for removing and analyzing film from commercially available menstrual pads>
When removing the film from a commercially available napkin, etc., use a cold spray to solidify the hot melt that adheres between the materials, and carefully peel off the film.
The peeled film is immersed in liquid nitrogen, taken out, and immediately cut in the thickness direction using a cutter blade. The cut film is placed on an observation table for a scanning electron microscope (SEM) so that the cut surface faces up, and the cut surface can be observed at a magnification of 700 times to confirm that the film has a layered structure.
The film having a layered structure is cut into 10 cm squares and immersed in a solvent capable of dissolving only either the elastic layer or the plastic layer to take out the elastic layer and the plastic layer, respectively. Therefore, when the elastic layer is taken out, the film is immersed in a solvent in which only the plastic layer is dissolved. When removing the plastic layer, the film is immersed in a solvent in which only the elastic layer is dissolved.

積層フィルム１０は、上記の積層構造を厚み方向に有したシートであり、表裏の第１面１０Ａ及び第２面１０Ｂを有する。本実施形態においては、第１面１０Ａ及び第２面１０Ｂの両面が塑性層２からなる。積層フィルム１０は、厚み方向に、一方の面から他方の面に突出する積層構造の凸部３を複数、離間して配した凹凸構造５を有する。凸部３は、弾性層１と塑性層２とが一体化して突出しており、突出した面の反対側の面は、弾性層１と塑性層２とが一体化して窪んで、凹部４とされている。すなわち、凸部３の内部は空洞にされている。 The laminated film 10 is a sheet having the above-mentioned laminated structure in the thickness direction, and has a first surface 10A and a second surface 10B on the front and back surfaces. In the present embodiment, both sides of the first surface 10A and the second surface 10B are made of the plastic layer 2. The laminated film 10 has a concavo-convex structure 5 in which a plurality of convex portions 3 of the laminated structure protruding from one surface to the other surface are arranged apart from each other in the thickness direction. In the convex portion 3, the elastic layer 1 and the plastic layer 2 are integrated and protrude, and the surface opposite to the protruding surface is formed as a concave portion 4 by integrating the elastic layer 1 and the plastic layer 2 and denting the convex portion 3. ing. That is, the inside of the convex portion 3 is made hollow.

凸部３は、一方の面から他方の面に突出するものとして、第１面１０Ａ及び第２面１０Ｂの両方に配される。本実施形態においては、凸部３は、第１面１０Ａ側に突出する第１凸部３１と、第２面側１０Ｂに突出する第２凸部３２とを有する。すなわち、本実施形態においては、凸部３はフィルム平面に対し、互いに反対方向に突出する部分を有する。第１凸部３１の第２面１０Ｂ側には第１凹部４１が配され、第２凸部３２の第１面１０Ａ側には第２凹部４２が配されている。 The convex portion 3 is arranged on both the first surface 10A and the second surface 10B so as to project from one surface to the other surface. In the present embodiment, the convex portion 3 has a first convex portion 31 projecting toward the first surface 10A side and a second convex portion 32 projecting toward the second surface side 10B. That is, in the present embodiment, the convex portion 3 has a portion protruding in the opposite direction to the film plane. The first concave portion 41 is arranged on the second surface 10B side of the first convex portion 31, and the second concave portion 42 is arranged on the first surface 10A side of the second convex portion 32.

凸部３は、積層フィルム１０の平面方向に互いに交差する複数の方向に配列されている。本実施形態においては、図２に示すように、第１面１０Ａ側に突出する第１凸部３１（第２面１０Ｂ側の第１凹部４１）と第２面１０Ｂ側に突出する第２凸部３２（第１面１０Ａ側の第２凹部４２）とが、Ｊ１方向、及びＪ１方向に直交するＪ２方向のそれぞれに沿って交互に配列されている。このように配列された凸部３は互いに連接しない独立の突起にされており、積層フィルム１０の平面方向に分散配置されている。 The convex portions 3 are arranged in a plurality of directions intersecting each other in the plane direction of the laminated film 10. In the present embodiment, as shown in FIG. 2, the first convex portion 31 (the first concave portion 41 on the second surface 10B side) protruding toward the first surface 10A side and the second convex portion protruding toward the second surface 10B side. The portions 32 (second concave portions 42 on the first surface 10A side) are alternately arranged along the J1 direction and the J2 direction orthogonal to the J1 direction. The convex portions 3 arranged in this way are independent protrusions that are not connected to each other, and are dispersedly arranged in the plane direction of the laminated film 10.

本実施形態におけるＪ１方向及びＪ２方向は、積層フィルム１０の幅方向（Ｘ方向）と長手方向（Ｙ方向）である。ただし、凸部３が配列される方向は、積層フィルム１０の平面方向である限り、Ｊ１方向及びＪ２方向に限定されるものではく、種々の互いに交差する方向とすることができる。また、凸部３が配列する方向同士が交差する角度の内で最も小さい角度αは、本実施形態のように直角（９０°）に限らず、種々の角度とすることができる。積層フィルム１０の柔らかい肌触りを実現する観点から、角度αは４５°以上であることが好ましく、６０°以上であることがより好ましく、７０°以上であることが更に好ましい。さらに、凸部３が配列される方向は、本実施形態のように２つの方向に限らず、３つ以上の方向であってもよい。凸部３が配列される方向が多いほど積層フィルム１０における凹凸構造５がより複雑なものとなり、肌触りの観点から好ましい。 The J1 direction and the J2 direction in the present embodiment are the width direction (X direction) and the longitudinal direction (Y direction) of the laminated film 10. However, the direction in which the convex portions 3 are arranged is not limited to the J1 direction and the J2 direction as long as it is the plane direction of the laminated film 10, and may be various directions intersecting each other. Further, the smallest angle α among the angles at which the directions in which the convex portions 3 are arranged intersect each other is not limited to a right angle (90 °) as in the present embodiment, and may be various angles. From the viewpoint of realizing the soft touch of the laminated film 10, the angle α is preferably 45 ° or more, more preferably 60 ° or more, and further preferably 70 ° or more. Further, the direction in which the convex portions 3 are arranged is not limited to two directions as in the present embodiment, and may be three or more directions. The more the convex portions 3 are arranged, the more complicated the uneven structure 5 in the laminated film 10 becomes, which is preferable from the viewpoint of touch.

凸部３の配列は、図１に示すように第１凸部３１と第２凸部３２とを交互に配列させた態様のみに限定されるものではない。図１に示す配列に加え、第１面１０Ａ側に突出する第１凸部３１同士が離間して並ぶ配列を含んでいてもよく、第２面１０Ｂ側に突出する第２凸部３２同士が離間して並ぶ配列を含んでいてもよい。 The arrangement of the convex portions 3 is not limited to the embodiment in which the first convex portion 31 and the second convex portion 32 are alternately arranged as shown in FIG. In addition to the arrangement shown in FIG. 1, the arrangement may include an arrangement in which the first convex portions 31 protruding toward the first surface 10A side are arranged apart from each other, and the second convex portions 32 protruding toward the second surface 10B side may be included. It may include an array arranged at a distance.

積層フィルム１０は、複数の凸部３を上記のように配列することにより、第１面１０Ａ及び第２面１０Ｂに平面方向に広がる凹凸構造５を有する。これにより、積層フィルム１０の表面（第１面１０Ａ又は第２面１０Ｂ）に触れた者は、手や体の肌表面が凹凸構造５に馴染み、布材様な柔らかさを感じることができる。また、積層フィルム１０は、凹凸構造５によって従来のフィルムよりも厚みを有しながら凹部４を備え、これに伴い触れた者に硬さよりもふっくらした触感と安心感を与えることができる。このふっくらした触感は、凸部３が有する弾性層１の弾力感によってより高められている。加えて、このような凹凸構造５が、第１面１０Ａ側の第１凸部３１と第２面１０Ｂ側の第２凸部３２とを備えることで、両面を凸で支えてより弾力感を高められる。 The laminated film 10 has a concavo-convex structure 5 extending in the plane direction on the first surface 10A and the second surface 10B by arranging the plurality of convex portions 3 as described above. As a result, a person who touches the surface of the laminated film 10 (first surface 10A or second surface 10B) can feel the softness of the cloth material as the skin surface of the hand or body becomes familiar with the uneven structure 5. Further, the laminated film 10 is provided with the concave portion 4 while having a thickness larger than that of the conventional film due to the uneven structure 5, and the person who touches the laminated film 10 can be given a fluffy feel and a sense of security rather than the hardness. This fluffy tactile sensation is further enhanced by the elastic sensation of the elastic layer 1 of the convex portion 3. In addition, such a concavo-convex structure 5 includes a first convex portion 31 on the first surface 10A side and a second convex portion 32 on the second surface 10B side, so that both sides are convexly supported to provide a more elastic feeling. Be enhanced.

積層フィルム１０において、凸部３と凸部３との間は、後述する部分延伸加工によって延伸された部分であり、凸部３に比べて透明度が下がり白色化している（以下、この部分を連結部６という。）。連結部６は、凸部３の配されない領域を平面方向に延在して複数条配されている。図１及び２においては凸部３を区画するように格子状に配されている。ただし、凸部３の配置はこれに限定されるものでは無く、凸部３の配置に合わせて種々設定することができる。連結部６は、積層フィルム１０の厚み方向において、シート面に対して傾斜しいてもよく、シート面に沿う平坦面であってもよく、湾曲面であってもよい。また連結部６は、第１凸部３１と第２凸部３２（第２凹部４２）とを段差なく連続的に繋ぐ壁面であってもよい。 In the laminated film 10, the portion between the convex portion 3 and the convex portion 3 is a portion stretched by a partial stretching process described later, and the transparency is lower than that of the convex portion 3 and the film is whitened (hereinafter, this portion is connected). Part 6). The connecting portion 6 extends in the plane direction in a region where the convex portion 3 is not arranged, and is arranged in a plurality of rows. In FIGS. 1 and 2, the convex portions 3 are arranged in a grid pattern so as to partition the convex portions 3. However, the arrangement of the convex portion 3 is not limited to this, and various settings can be made according to the arrangement of the convex portion 3. The connecting portion 6 may be inclined with respect to the sheet surface in the thickness direction of the laminated film 10, may be a flat surface along the sheet surface, or may be a curved surface. Further, the connecting portion 6 may be a wall surface that continuously connects the first convex portion 31 and the second convex portion 32 (second concave portion 42) without a step.

透明度が低下し白色化した連結部６は、例えば図３（Ａ）及び（Ｂ）に示す図面代用写真に示されるように、視覚によって、凸部３と対比して確認することができる。図３（Ａ）においては、連結部６が、第１凸部３１（第１凹部４１）と第２凸部３２（第２凹部４２）との間を繋いで配されている。図３（Ｂ）においては、連結部６が、第２凸部３２（第２凹部４２）同士の間を繋いで配されている。
なお、連結部６は常に白色化する訳ではなく、フィルムの材質によっては連結部６の透明度は低下せず、連結部６が白色化しないこともある。連結部６が白色化する理由は定かでないが、図３（Ａ）及び（Ｂ）における本実施形態の積層フィルム１０の特徴から、以下のように考えられる。
すなわち、本実施形態の積層フィルム１０は、塑性層２が炭酸カルシウム粒子含有の直鎖状低密度ポリエチレン、弾性層１がポリウレタンからできたフィルムを、２．７倍部分延伸したものである。そのため、積層フィルム１０が延伸されることで、炭酸カルシウム粒子とポリエチレンの界面で剥離・開孔が生じ、積層フィルム１０に小さな孔が多数生じ得る。また、積層フィルム１０が延伸されると、ポリエチレンの分子が微結晶構造を無数に形成し得る。このような現象により、積層フィルム１０の延伸部分において透過光が散乱し、連結部６が白色化すると考えられる。
以上のことから、上記の現象が生じない場合、例えば延伸倍率が小さい場合や、結晶構造を形成しないポリマー（非晶性高分子など）を用いた場合であれば、積層フィルム１０が部分延伸された領域が白色化しないことは有り得る。 The connecting portion 6 having reduced transparency and whitening can be visually confirmed in comparison with the convex portion 3, as shown in, for example, the drawing substitute photographs shown in FIGS. 3 (A) and 3 (B). In FIG. 3A, the connecting portion 6 is arranged so as to connect between the first convex portion 31 (first concave portion 41) and the second convex portion 32 (second concave portion 42). In FIG. 3B, the connecting portion 6 is arranged so as to connect the second convex portions 32 (second concave portions 42) to each other.
The connecting portion 6 is not always whitened, and depending on the material of the film, the transparency of the connecting portion 6 does not decrease, and the connecting portion 6 may not be whitened. The reason why the connecting portion 6 is whitened is not clear, but it is considered as follows from the characteristics of the laminated film 10 of the present embodiment in FIGS. 3A and 3B.
That is, the laminated film 10 of the present embodiment is a film obtained by partially stretching a film in which the plastic layer 2 is made of linear low-density polyethylene containing calcium carbonate particles and the elastic layer 1 is made of polyurethane. Therefore, when the laminated film 10 is stretched, peeling / opening occurs at the interface between the calcium carbonate particles and polyethylene, and many small pores may be generated in the laminated film 10. Further, when the laminated film 10 is stretched, polyethylene molecules can form innumerable microcrystal structures. It is considered that due to such a phenomenon, transmitted light is scattered in the stretched portion of the laminated film 10 and the connecting portion 6 is whitened.
From the above, if the above phenomenon does not occur, for example, if the draw ratio is small, or if a polymer that does not form a crystal structure (amorphous polymer, etc.) is used, the laminated film 10 is partially stretched. It is possible that the area is not whitened.

凸部３の配列方向（本実施形態においてはＸ方向及びＹ方向）における、凸部３の長さ（Ｗ１）の、該配列方向の凸部３同士の間に挟まれた連結部６の前記配列方向の幅（Ｗ２）に対する比（Ｗ１／Ｗ２）は、柔らかい肌触りの向上の観点から、０．５以上が好ましく、０．８以上がより好ましく、１以上が更に好ましい。また、前記比（Ｗ１／Ｗ２）は、積層フィルムを吸収体などの部材に貼り合わせた時、積層フィルムと部材との十分な剥離強度を担保する観点から、１．８以下が好ましく、１．５以下がより好ましく、１．２以下が更に好ましい。 The said of the connecting portion 6 sandwiched between the convex portions 3 in the arrangement direction of the length (W1) of the convex portions 3 in the arrangement direction of the convex portions 3 (X direction and Y direction in the present embodiment). The ratio (W1 / W2) to the width (W2) in the arrangement direction is preferably 0.5 or more, more preferably 0.8 or more, still more preferably 1 or more, from the viewpoint of improving the soft touch. The ratio (W1 / W2) is preferably 1.8 or less from the viewpoint of ensuring sufficient peel strength between the laminated film and the member when the laminated film is attached to a member such as an absorber. 5 or less is more preferable, and 1.2 or less is further preferable.

積層フィルム１０おいて、柔らかさが平面方向に均質に感じられるよう、上記の凹凸構造５における凸部３が周期的に配列されていることが好ましく、一定のピッチで配列されていることがより好ましい。 In the laminated film 10, it is preferable that the convex portions 3 in the above-mentioned uneven structure 5 are arranged periodically so that the softness can be felt uniformly in the plane direction, and it is more preferable that the convex portions 3 are arranged at a constant pitch. preferable.

積層フィルム１０は、前述した凹凸構造５に加え、該凹凸構造５よりも高低差が小さい起伏構造７を有することが好ましい（図４）。起伏構造７における起伏は、光学顕微鏡を用いて観察しても確認できない程小さく、ＳＥＭを用いて観察（倍率：約１００倍以上）をして確認できる微細なものである。これに対し、前述した凹凸構造５の凹凸は、積層フィルム１０の断面に対して光学顕微鏡を用いて観察して確認できる大きさのものである。このように相対的な大きさの違いから、凹凸構造５をマクロな凹凸構造、起伏構造７をミクロな凹凸構造と言うことがある。 In addition to the uneven structure 5 described above, the laminated film 10 preferably has an undulating structure 7 having a smaller height difference than the uneven structure 5 (FIG. 4). The undulations in the undulation structure 7 are so small that they cannot be confirmed even when observed with an optical microscope, and are fine ones that can be confirmed by observing with an SEM (magnification: about 100 times or more). On the other hand, the unevenness of the uneven structure 5 described above has a size that can be confirmed by observing the cross section of the laminated film 10 with an optical microscope. Due to the relative difference in size, the uneven structure 5 may be referred to as a macro uneven structure, and the undulating structure 7 may be referred to as a micro uneven structure.

起伏構造７は、例えば倍率７００倍にしたＳＥＭ写真に基づいて積層フィルム１０の表面を観察し、長さ１００μｍの幅の中に溝の有無を確認することで判断することができる。図５は倍率７５０倍にしたＳＥＭ写真であり、起伏構造７があると思われる領域Ｒ１と無いと思われる領域Ｒ２とが示されている。そして図５の領域Ｒ１に、長さ１００μｍの幅の中に起伏構造７の溝７１があり、起伏構造７を有すると判断される。同様に、図５の領域Ｒ２に、長さ１００μｍの幅の中に起伏構造７の溝が無く、起伏構造７を有さないと判断される。このようにして、積層フィルム１０における起伏構造７の領域を画定することができる。
なお、図５に示す積層フィルム１０は、塑性層２に炭酸カルシウムの粒子を含有する（含有量２０質量％）。炭酸カルシウムの粒子は、前述の凹凸構造５及び起伏構造７の形成のために部分延伸した際に、表面に露出している。この炭酸カルシウムの粒子の含有量又は含有の有無が起伏構造７の形成に影響されるものではない。 The undulating structure 7 can be determined by observing the surface of the laminated film 10 based on, for example, an SEM photograph at a magnification of 700 times, and confirming the presence or absence of grooves in a width of 100 μm in length. FIG. 5 is an SEM photograph at a magnification of 750 times, showing a region R1 in which the undulating structure 7 is considered to be present and a region R2 in which the undulating structure 7 is not considered to be present. Then, in the region R1 of FIG. 5, there is a groove 71 of the undulating structure 7 in a width of 100 μm in length, and it is determined that the undulating structure 7 is provided. Similarly, it is determined that the region R2 of FIG. 5 does not have the groove of the undulating structure 7 in the width of 100 μm in length and does not have the undulating structure 7. In this way, the region of the undulating structure 7 in the laminated film 10 can be defined.
The laminated film 10 shown in FIG. 5 contains calcium carbonate particles in the plastic layer 2 (content 20% by mass). The calcium carbonate particles are exposed on the surface when partially stretched for the formation of the uneven structure 5 and the undulating structure 7 described above. The content or presence / absence of the calcium carbonate particles is not affected by the formation of the undulating structure 7.

起伏構造７は、図４に示すように、弾性層１と塑性層２との積層構造の表面に形成されている。この場合、起伏構造７は、上記のように微細な起伏を有するものであれば、塑性層２のみからなっていてもよく、塑性層２及び弾性層１からなっていてもよい。 As shown in FIG. 4, the undulating structure 7 is formed on the surface of a laminated structure of the elastic layer 1 and the plastic layer 2. In this case, the undulating structure 7 may be composed of only the plastic layer 2 or may be composed of the plastic layer 2 and the elastic layer 1 as long as the undulating structure 7 has fine undulations as described above.

このような起伏構造７は、前述した凹凸構造５と相俟って、積層フィルム１０に触れた者の手や体の肌表面に微細な非接触部分をつくり、密着しすぎないフィット感を与えることができる。特に指等を平面方向に動かしたとき、凸部３及び凹部４と指等が擦り合って凹凸を感じながら、微細な起伏構造７が指等の動きに追従して接触しやすくなる。このような接触において、積層フィルム１０は、触れた者に更に布材様な柔らかい触感を与えることができる。 Such an undulating structure 7, in combination with the above-mentioned uneven structure 5, creates a fine non-contact portion on the skin surface of the hand or body of a person who touches the laminated film 10 and gives a fit feeling that does not adhere too much. be able to. In particular, when the finger or the like is moved in the plane direction, the convex portion 3 and the concave portion 4 rub against each other and the finger or the like feels unevenness, and the fine undulating structure 7 follows the movement of the finger or the like and easily comes into contact with the finger or the like. In such contact, the laminated film 10 can give the person who touches the film a soft tactile sensation like a cloth material.

起伏構造７は、図５に示すように、平面方向における一方向に延在する凸条部７２を有することが好ましい。この一方向は、積層フィルム１０の平面方向における種々の方向とすることができる。例えば、凹凸構造５の凸部３が離間して配列される方向に沿って延在していてもよく、配列される方向とは異なる方向（交差する方向）に延在していてもよい。例えば、図１に示すＸ方向及びＹ方向に沿って凸条部７２が延在していてもよく、Ｘ方向及びＹ方向と交差する方向に沿って凸条部７２が延在していてもよい。この場合、前記一方向は、凹凸構造５の凸部３が離間配列されるＪ１方向及びＪ２方向のいずれかに一致する。
起伏構造７は、凸条部７２を有することによって、マクロな凹凸構造５とは異なる触感を作り出すことができる。これにより、積層フィルム１０は単調にならない複雑な触感を与える。積層フィルム１０は、例えば手や体の肌表面が積層フィルム１０に対して多様な接触、多方向からの平面に沿った接触に対応して、変化に富んだ柔らかさを作り出すことができる。具体的には、マクロな凹凸構造５においては、凸部３が互いに連接しない独立突起であり、平面方向に沿って色々な方向から接触しても、同じような凹凸感を与える。これに対し、ミクロな凹凸構造である起伏構造７は、筋状の凸条部７２を有することによって、凸条部７２の延在方向と交差する方向からの接触では凸条部７２の曲面を撫でるように接触して凸条部７２の丸みを感じる。その触感は、凸条部７２の延在方向と接触する方向とのなす角度が直角に近づく程強くなる。また、接触する方向が延在方向に近づく程、凸条部７２の頂部に沿って接触しなめらかな感触となる。これらが触れる者の様々な動きに応じて異なる感触を与え、変化に富んだ柔らかさを作り出す。 As shown in FIG. 5, the undulating structure 7 preferably has a ridge portion 72 extending in one direction in the plane direction. This one direction can be various directions in the plane direction of the laminated film 10. For example, the convex portions 3 of the concave-convex structure 5 may extend along the direction in which they are arranged apart from each other, or may extend in a direction different from the direction in which they are arranged (intersecting direction). For example, the ridges 72 may extend along the X and Y directions shown in FIG. 1, and the ridges 72 may extend along the directions intersecting the X and Y directions. good. In this case, the one direction corresponds to either the J1 direction or the J2 direction in which the convex portions 3 of the concave-convex structure 5 are spaced apart from each other.
By having the ridge portion 72, the undulating structure 7 can create a tactile sensation different from that of the macro uneven structure 5. As a result, the laminated film 10 gives a complicated tactile sensation that does not become monotonous. The laminated film 10 can produce a variety of softness, for example, when the skin surface of the hand or body responds to various contacts with the laminated film 10 and contact along a plane from multiple directions. Specifically, in the macroscopic uneven structure 5, the convex portions 3 are independent protrusions that are not connected to each other, and even if they come into contact with each other from various directions along the plane direction, the same unevenness feeling is given. On the other hand, the undulating structure 7, which is a micro-concavo-convex structure, has the ridges 72 having streaks, so that the curved surface of the ridges 72 is formed by contact from the direction intersecting the extending direction of the ridges 72. You can feel the roundness of the ridges 72 by touching them as if you were stroking them. The tactile sensation becomes stronger as the angle formed by the extending direction of the ridge portion 72 and the contacting direction approaches a right angle. Further, the closer the contact direction is to the extending direction, the smoother the contact is along the top of the convex portion 72. These give different feels to the various movements of the toucher, creating a variety of softness.

起伏構造７を有する部分における積層フィルムの層厚み（弾性層１と塑性層２とを合わせた層厚み）Ｈ１は、図６に示すように、起伏構造７以外の部分（例えばマクロな凹凸構造５の凸部３）における積層フィルムの層厚み（弾性層１と塑性層２とを合わせた層厚み）Ｈ２よりも薄くされていることが好ましい。これにより層厚みが薄くされた部分が屈曲点として作用し、積層フィルム１０全体の曲げ剛性が低減しより柔らかく感じることができる。 As shown in FIG. 6, the layer thickness (layer thickness of the elastic layer 1 and the plastic layer 2 combined) H1 of the laminated film in the portion having the undulating structure 7 is a portion other than the undulating structure 7 (for example, a macro uneven structure 5). It is preferable that the thickness of the laminated film in the convex portion 3) is smaller than that of H2 (the combined thickness of the elastic layer 1 and the plastic layer 2). As a result, the portion where the layer thickness is thinned acts as a bending point, and the bending rigidity of the entire laminated film 10 is reduced, so that the film can be felt softer.

＜フィルムの層厚みの測定方法＞
液体窒素を用いて凍結させた積層フィルム１０を、カッター刃を用いて厚み方向に切断する。そして、切断面が上になる向きで積層フィルム１０を無荷重状態でＳＥＭ用観察台に設置し、ＳＥＭにより倍率１０００倍で観察することにより層厚みＨ１、Ｈ２を１０点測定し、その平均値をそれぞれの測定値とする。 <Measuring method of film layer thickness>
The laminated film 10 frozen with liquid nitrogen is cut in the thickness direction using a cutter blade. Then, the laminated film 10 is placed on an observation table for SEM with the cut surface facing up, and the layer thicknesses H1 and H2 are measured at 10 points by observing at a magnification of 1000 times by SEM, and the average value thereof is measured. Let be each measured value.

起伏構造７は、前述の複雑な触感の観点から、一方向に延在する凸条部７２に加え、平面方向における前記一方向と交差する異なる方向に延在する別の凸条部７２を有することがより好ましい。これにより、多方向からの接触に対してより対応できる変化に富んだ柔らかさを作り出すことができる。この一方向、該一方向と交差する異なる方向とは、図１に示すＸ方向及びＹ方向であってもよく、Ｘ方向及びＹ方向と交差する方向であってもよい。凸条部７２が延在する２つの交差する方向がＸ方向及びＹ方向である場合、該２つの交差する方向は、凹凸構造５の凸部３が離間配列されるＪ１方向及びＪ２方向に一致する。 The undulating structure 7 has a ridge portion 72 extending in one direction and another ridge portion 72 extending in a different direction intersecting the one direction in the plane direction from the viewpoint of the above-mentioned complicated tactile sensation. Is more preferable. This makes it possible to create a variety of softness that is more responsive to contact from multiple directions. This one direction and the different directions intersecting the one direction may be the X direction and the Y direction shown in FIG. 1, or may be the directions intersecting the X direction and the Y direction. When the two intersecting directions in which the convex portions 72 extend are the X direction and the Y direction, the two intersecting directions coincide with the J1 direction and the J2 direction in which the convex portions 3 of the concave-convex structure 5 are spaced apart from each other. do.

また、起伏構造７は、少なくともマクロな凹凸構造５の凸部３、３間に存在することが好ましい。すなわち、起伏構造７は、図１及び２に示す連結部６に配されていることが好ましい。これにより、指等で積層フィルム１０の表面を撫でたとき、凸部３の間で起伏構造７に触れやすく、布材様な柔らかい触感をより明確に感じさせることができる。また、連結部６の延在する方向に沿って、起伏構造７の凸条部７２が延在していると、前述した複雑な触感がより明確に感じられて好ましい。さらに同様の観点から、連結部６が積層フィルム１０の平面方向に互いに交差する複数の方向（図１及び２においてはＸ方向とＹ方向）に延在している場合、これらの複数の方向それぞれに沿って延在する別々の凸条部７２が配されていることが好ましい。 Further, it is preferable that the undulating structure 7 exists at least between the convex portions 3 and 3 of the macro uneven structure 5. That is, it is preferable that the undulating structure 7 is arranged in the connecting portion 6 shown in FIGS. 1 and 2. As a result, when the surface of the laminated film 10 is patted with a finger or the like, the undulating structure 7 can be easily touched between the convex portions 3, and a soft tactile sensation like a cloth material can be felt more clearly. Further, it is preferable that the convex portion 72 of the undulating structure 7 extends along the extending direction of the connecting portion 6, because the above-mentioned complicated tactile sensation can be felt more clearly. Further, from the same viewpoint, when the connecting portion 6 extends in a plurality of directions (X direction and Y direction in FIGS. 1 and 2) intersecting each other in the plane direction of the laminated film 10, each of these plurality of directions is used. It is preferable that separate ridges 72 extending along the line are arranged.

この起伏構造７の平面方向における配置は、図１及び２に示す格子状の連結部６に対応した配置に限らず、種々設定することができる。例えば、以下の（Ａ１）～（Ａ７）に示す態様が挙げられる。（Ａ１）～（Ａ７）のいずれの態様においても、起伏構造７が連結部６に配されるものとして示している。
（Ａ１）
凹凸構造５の凸部３の配列方向、及び起伏構造７の凸条部７２の延在方向（連結部６の延在方向）を積層フィルムの幅方向（Ｘ方向）及び長手方向（Ｙ方向）の少なくともいずれか一方に対して交差する方向とする態様。
（Ａ２）
凹凸構造５の凸部３の離間配列する列同士の間隔、及び起伏構造７の凸条部７２（連結部６）同士の間隔の少なくともいずれか一方が、均等でない態様。例えば、積層フィルム１０の周囲よりも中央部分で前記間隔が狭くされている態様。
（Ａ３）
図１における配置において、起伏構造７（連結部６）が連続的に延在するのではなく、破線状に離間して延在している態様。
（Ａ４）
図１における配置において、起伏構造７（連結部６）が幅違いの延在列を有する態様。
（Ａ５）
図１における配置において、起伏構造７（連結部６）が積層フィルム１０の端部までには達しない配置とする態様。
（Ａ６）
凸部３が平面形状として複数の異なる多角形状を有し、概ね幅方向（Ｘ方向）及び長手方向（Ｙ方向）に沿って離間配置され、これに対して起伏構造７（連結部６）の延在方向を前記多角形の各辺に沿う方向とする等、起伏構造７（連結部６）の延在方向がより複雑にされた態様。
（Ａ７）
起伏構造７の凸条部７２（連結部６）を波状に延在させる態様。 The arrangement of the undulating structure 7 in the plane direction is not limited to the arrangement corresponding to the grid-like connecting portion 6 shown in FIGS. 1 and 2, and various settings can be made. For example, the embodiments shown in the following (A1) to (A7) can be mentioned. In any of the embodiments (A1) to (A7), the undulating structure 7 is shown as being arranged on the connecting portion 6.
(A1)
The arrangement direction of the convex portions 3 of the uneven structure 5 and the extending direction of the convex portions 72 of the undulating structure 7 (extending direction of the connecting portion 6) are the width direction (X direction) and the longitudinal direction (Y direction) of the laminated film. A mode in which the directions intersect with at least one of the above.
(A2)
An embodiment in which at least one of the distance between the rows of the convex portions 3 of the concave-convex structure 5 and the distance between the convex portions 72 (connecting portions 6) of the undulating structure 7 is not uniform. For example, an embodiment in which the spacing is narrower in the central portion than the periphery of the laminated film 10.
(A3)
In the arrangement in FIG. 1, the undulating structure 7 (connecting portion 6) does not extend continuously, but extends apart in a broken line shape.
(A4)
In the arrangement in FIG. 1, the undulating structure 7 (connecting portion 6) has an extending row having different widths.
(A5)
In the arrangement shown in FIG. 1, the arrangement is such that the undulating structure 7 (connecting portion 6) does not reach the end portion of the laminated film 10.
(A6)
The convex portion 3 has a plurality of different polygonal shapes as a planar shape, and is spaced apart from each other along the width direction (X direction) and the longitudinal direction (Y direction), whereas the undulating structure 7 (connecting portion 6) has a convex portion 3. An embodiment in which the extending direction of the undulating structure 7 (connecting portion 6) is made more complicated, such that the extending direction is a direction along each side of the polygon.
(A7)
A mode in which the convex portion 72 (connecting portion 6) of the undulating structure 7 is extended in a wavy shape.

次に、本発明の積層フィルムの製造方法の好ましい形態について説明する。 Next, a preferred embodiment of the method for producing a laminated film of the present invention will be described.

まず、図７（Ａ）に示すように、弾性層１と塑性層２とを有し、塑性層２を最表面とする積層構造の原料フィルム１００を準備する。図７（Ａ）では、弾性層１の両面に一対の塑性層２を積層した３層構造を有するものとしているが、これに限定されるものではない。 First, as shown in FIG. 7A, a raw material film 100 having a laminated structure having an elastic layer 1 and a plastic layer 2 and having the plastic layer 2 as the outermost surface is prepared. In FIG. 7A, it is assumed that the elastic layer 1 has a three-layer structure in which a pair of plastic layers 2 are laminated on both sides, but the present invention is not limited to this.

原料フィルム１００に対して、該原料フィルム１００の平面方向における互いに交差する複層の方向に部分延伸を行う（部分延伸工程）。ここでいう部分延伸とは、原料フィルム１００全体を牽引して均一な延伸を行うのではなく、原料フィルム１００の一部分を延伸することをいう。具体的には、図７（Ｂ）に示すように、互いに噛み合う歯と溝とを有する一対のギアロール２００、２１０間に、原料フィルム１００を挟み込む処理を行う。より具体的には、ギアロール２００の歯２０１がギアロール２１０の溝２１２に遊挿され、ギアロール２１０の歯２１１がギアロール２００の溝２０２に遊挿される。この一対のギアロール２００、２１０に間に原料フィルム１００を搬送し、原料フィルム１００の両面に対し、一対のギアロール２００、２１０が噛み合って互いに反対方向に押し込む。これにより、ギアロール２００の歯２０１と、ギアロール２１０の歯２１１とが原料フィルム１００に当接し、当接した原料フィルム１００の部分１０１及び１０２の間の部分１０３において、部分延伸が行われる。すなわち、原料フィルム１００の部分１０１、１０２が互いに反対方向に押し込まれ、その反対方向へ押し込む力が、原料フィルム１００の部分１０３に作用して部分延伸される。 The raw material film 100 is partially stretched in the direction of the plurality of layers intersecting each other in the plane direction of the raw material film 100 (partial stretching step). The term "partial stretching" as used herein means that a part of the raw material film 100 is stretched instead of pulling the entire raw material film 100 to perform uniform stretching. Specifically, as shown in FIG. 7B, a process of sandwiching the raw material film 100 between a pair of gear rolls 200 and 210 having teeth and grooves that mesh with each other is performed. More specifically, the teeth 201 of the gear roll 200 are loosely inserted into the groove 212 of the gear roll 210, and the teeth 211 of the gear roll 210 are loosely inserted into the groove 202 of the gear roll 200. The raw material film 100 is conveyed between the pair of gear rolls 200 and 210, and the pair of gear rolls 200 and 210 mesh with each other on both sides of the raw material film 100 and are pushed in opposite directions. As a result, the teeth 201 of the gear roll 200 and the teeth 211 of the gear roll 210 come into contact with the raw material film 100, and partial stretching is performed at the portion 103 between the portions 101 and 102 of the abutting raw material film 100. That is, the portions 101 and 102 of the raw material film 100 are pushed in opposite directions to each other, and the force of pushing in the opposite directions acts on the portion 103 of the raw material film 100 to partially stretch the raw material film 100.

ギアロール２００、２１０として、歯２０１及び２１１を円盤状にしてロール軸方向に並べたものを用いる場合がある（第一態様）。また、歯２０１及び２１１をロール軸方向に延在して、ロール周面方向に離間させて複数配置したものを用いる場合がある（第二態様）。第一態様及び第二態様の場合は、２回に分けて延伸方向を変えて部分延伸加工を行う。
第一態様のロールを用いて第１回目の部分延伸加工を行う場合、原料フィルム１００は、ロール軸方向に並ぶ円盤状の歯の間で原料フィルム１００を幅方向（Ｘ方向）に部分延伸する。部分延伸された部分は、原料フィルム１００の長手方向（Ｙ方向）に延在する。次に、第二態様のロールを用いて第２回目の部分延伸加工を行う。これにより、原料フィルム１００は、ロール周面方向に並ぶ歯の間で原料フィルム１００を長手方向（Ｙ方向）に部分延伸する。部分延伸された部分は、原料フィルム１００の幅方向（Ｘ方向）に延在する。これにより、幅方向（Ｘ方向）及び長手方向（Ｙ方向）に延在し格子状にされた連結部６が形成され、連結部６に囲まれた部分が独立突起にされた凸部３が平面方向に互いに離間し、幅方向と長手方向に配列される。これにより、図１及び２に示す積層フィルム１０が形成される。このように連結部６が部分延伸された部分であるため、弾性層１及び塑性層２、特に塑性層２が延伸される。このとき、場合によっては、連結部６は透明度が低下し白色化することがある。 As the gear rolls 200 and 210, teeth 201 and 211 may be arranged in a disk shape in the roll axis direction (first aspect). Further, there is a case where a plurality of teeth 201 and 211 are extended in the roll axis direction and are spaced apart from each other in the roll peripheral surface direction (second aspect). In the case of the first aspect and the second aspect, the partial stretching process is performed by changing the stretching direction in two steps.
When the first partial stretching process is performed using the roll of the first aspect, the raw material film 100 partially stretches the raw material film 100 in the width direction (X direction) between the disk-shaped teeth arranged in the roll axis direction. .. The partially stretched portion extends in the longitudinal direction (Y direction) of the raw material film 100. Next, the second partial stretching process is performed using the roll of the second aspect. As a result, the raw material film 100 partially stretches the raw material film 100 in the longitudinal direction (Y direction) between the teeth arranged in the roll peripheral surface direction. The partially stretched portion extends in the width direction (X direction) of the raw material film 100. As a result, the connecting portion 6 extending in the width direction (X direction) and the longitudinal direction (Y direction) and forming a grid pattern is formed, and the convex portion 3 in which the portion surrounded by the connecting portion 6 is made into an independent protrusion is formed. They are separated from each other in the plane direction and arranged in the width direction and the longitudinal direction. As a result, the laminated film 10 shown in FIGS. 1 and 2 is formed. Since the connecting portion 6 is a partially stretched portion in this way, the elastic layer 1 and the plastic layer 2, particularly the plastic layer 2, are stretched. At this time, in some cases, the transparency of the connecting portion 6 may decrease and the connecting portion 6 may be whitened.

また、上記の部分延伸加工においては、塑性層２が塑性変形するレベルに延伸すると、その部分において前述した凸条部７２を有する起伏構造７が形成されて好ましい。それは次のようにして塑性層２が収縮することによる。すなわち、図８（Ａ）のように弾性層１と塑性層２とを有する原料フィルム１００を、塑性層２が塑性変形する程度に、図８（Ｂ）に示すように部分延伸する。この場合、図８（Ｃ）に示すように、塑性層２が塑性変形する一方で、弾性層１が弾性回復すると、元の長さに戻れなかった塑性層２が弾性層１に連れられて長さが縮まる。塑性層２は塑性変形した分、長さが元の長さよりも延び、弾性層１の収縮に伴って微細な筋状の凸条部７２が複数配された起伏構造７が形成される。このように塑性層２が塑性変形する部分は、最も強い延伸力が加えられた連結部６において主に形成される。このとき、場合によっては、積層フィルムの透明度はより明確に低下し白色化することがある。また、部分延伸の倍率や弾性層１が有する弾性率などによって、弾性層１が伸ばされた分、厚みが薄くなる場合がある。この場合、前述した図６に示すように、積層フィルム１０の層厚みＨ１が他の部分の層厚みＨ２よりも薄くなる。 Further, in the above partial stretching process, when the plastic layer 2 is stretched to a level where it is plastically deformed, the undulating structure 7 having the above-mentioned ridge portion 72 is formed in that portion, which is preferable. This is due to the shrinkage of the plastic layer 2 as follows. That is, the raw material film 100 having the elastic layer 1 and the plastic layer 2 as shown in FIG. 8A is partially stretched as shown in FIG. 8B to the extent that the plastic layer 2 is plastically deformed. In this case, as shown in FIG. 8C, when the plastic layer 2 is plastically deformed while the elastic layer 1 is elastically restored, the plastic layer 2 that could not return to its original length is brought to the elastic layer 1. The length shrinks. The length of the plastic layer 2 is longer than the original length by the amount of plastic deformation, and an undulating structure 7 in which a plurality of fine streaky ridges 72 are arranged is formed as the elastic layer 1 contracts. The portion where the plastic layer 2 is plastically deformed in this way is mainly formed in the connecting portion 6 to which the strongest stretching force is applied. At this time, in some cases, the transparency of the laminated film may be lowered more clearly and whitening may occur. Further, depending on the magnification of partial stretching, the elastic modulus of the elastic layer 1, and the like, the thickness of the elastic layer 1 may be reduced by the amount of stretching. In this case, as shown in FIG. 6 described above, the layer thickness H1 of the laminated film 10 is thinner than the layer thickness H2 of the other portion.

あるいは、上記の第一態様及び第二態様を組み合わせた加工方法以外に、次の第三態様の方法で積層フィルム１００を製造することができる。
すなわち、第三態様としては、一対のギアロール２００、２１０のロール周面に、凹凸構造５の凸部３の配列パターンに合わせて歯２０１、２１１を配置したもの（ピンロール）を用いることができる。この場合、１回の部分延伸加工において、歯２０１、２１１の配置パターンに合わせて互いに交差する複数の方向に同時に部分延伸することができる。 Alternatively, the laminated film 100 can be manufactured by the method of the following third aspect in addition to the processing method combining the first aspect and the second aspect described above.
That is, as a third aspect, a pair (pin roll) in which teeth 201 and 211 are arranged on the roll peripheral surfaces of the pair of gear rolls 200 and 210 in accordance with the arrangement pattern of the convex portions 3 of the concave-convex structure 5 can be used. In this case, in one partial stretching process, partial stretching can be performed simultaneously in a plurality of directions intersecting each other according to the arrangement pattern of the teeth 201 and 211.

本発明の積層フィルムは、種々の物品の肌に触れる表面に配することができる。特に、吸収性物品の裏面シートに用いると、厚みを高めることなく布材様の柔らかい肌触りが得られる。これにより、吸収性物品に触れた使用者が、つけ心地のよい安心感のある装着性を想起することができる。なかでも、塑性層を吸収性物品の最裏面に露出させて本発明の積層フィルムを配した形態が好ましい。
本発明の積層フィルムは、様々な吸収性物品に特に制限なく適用することができる。例えば、成人用や乳幼児用の使い捨ておむつ、生理用ナプキン、パンティーライナー、尿取りパッド等の裏面シートなどに適用することができる。 The laminated film of the present invention can be placed on the surface of various articles that come into contact with the skin. In particular, when it is used as a back sheet of an absorbent article, a soft touch like a cloth can be obtained without increasing the thickness. As a result, the user who comes into contact with the absorbent article can recall a comfortable and secure fit. Among them, a form in which the plastic layer is exposed on the innermost back surface of the absorbent article and the laminated film of the present invention is arranged is preferable.
The laminated film of the present invention can be applied to various absorbent articles without particular limitation. For example, it can be applied to disposable diapers for adults and infants, sanitary napkins, panty liners, back sheets such as urine absorbing pads, and the like.

本発明の積層フィルムを含む吸収性物品は、表面シート、裏面シート、及び、これらのシートに挟まれた吸収体を有する。吸収性物品の構成部材には、当該技術分野において通常用いられている材料を特に制限無く用いることができる。例えば、表面シートとしては、液透過性のある肌触りの柔らかいものを用いることができる。吸収性物品は更に、該吸収性物品の具体的な用途に応じた各種部材を具備していてもよい。例えば吸収性物品を使い捨ておむつや生理用ナプキンに適用する場合には、表面シート上の左右両側部に一対又は二対以上の立体ガードを配置することができる。 The absorbent article containing the laminated film of the present invention has a front surface sheet, a back surface sheet, and an absorber sandwiched between these sheets. Materials usually used in the art can be used as the constituent members of the absorbent article without particular limitation. For example, as the surface sheet, a liquid-permeable and soft surface sheet can be used. The absorbent article may further include various members according to the specific use of the absorbent article. For example, when an absorbent article is applied to a disposable diaper or a menstrual napkin, a pair or two or more pairs of three-dimensional guards can be arranged on the left and right sides of the surface sheet.

以下、本発明を実施例に基づきさらに詳しく説明するが、本発明はこれにより限定して解釈されるものではない。 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

（実施例１）
ポリウレタンからなる弾性層１、炭酸カルシウム粒子を含有した直鎖状低密度ポリエチレンからなる塑性層２を積層した図７（Ａ）に示す３層構造の原料フィルム１００を準備した。次いで、ギアロール２００、２１０として、歯を円盤状にしてロール軸方向に並べたギアロールを一対対向配置させたものと、歯をロール軸方向に延在して、ロール周面方向に離間させて複数配置したギアロールを一対対向配置させたものとを用いて、２回に分けて部分延伸加工を行った。その際、第１回目の部分延伸加工の延伸方向に対して、第２回目の部分延伸加工の延伸方向を９０°として行った。第１回目及び第２回目の延伸倍率をいずれも２．７倍とした。このようにして原料フィルム１００に対し２回の部分延伸加工をして、実施例１の積層フィルム試料を作製した。実施例１のフィルムは、一方向の面から多方向の面に突出する積層構造の凸部の間隔は２．０ｍｍであり、平面方向に互いに９０°で交差する複数方向に配列されている。また、起伏構造は、凸部の間に存在し、かつ、凸部が離間して配列される方向に沿って延在している。 (Example 1)
A raw material film 100 having a three-layer structure shown in FIG. 7 (A) in which an elastic layer 1 made of polyurethane and a plastic layer 2 made of linear low-density polyethylene containing calcium carbonate particles were laminated was prepared. Next, as the gear rolls 200 and 210, a pair of gear rolls having teeth arranged in a disk shape and arranged in the roll axis direction are arranged so as to face each other, and a plurality of gear rolls 200 and 210 having teeth extending in the roll axis direction and separated in the roll peripheral surface direction. Partial stretching was performed in two steps using a pair of arranged gear rolls arranged so as to face each other. At that time, the stretching direction of the second partial stretching process was set to 90 ° with respect to the stretching direction of the first partial stretching process. The first and second draw ratios were both 2.7 times. In this way, the raw material film 100 was partially stretched twice to prepare the laminated film sample of Example 1. In the film of Example 1, the distance between the convex portions of the laminated structure protruding from the unidirectional surface to the multidirectional surface is 2.0 mm, and the films are arranged in a plurality of directions intersecting each other at 90 ° in the plane direction. Further, the undulating structure exists between the convex portions and extends along the direction in which the convex portions are arranged apart from each other.

（実施例２）
第２回目の部分延伸加工に実施例１と同様のギアロールを用い、第１回目の部分延伸加工の延伸方向に対して、第２回目の部分延伸加工の延伸方向を１１０°とした以外は、実施例１と同様にして、実施例２の積層フィルム試料を作製した。実施例２のフィルムは、凹凸構造の凸部の間隔は２．０ｍｍであり、平面方向に互いに１１０°で交差する複数方向に配列されている。起伏構造は、実施例１と同様である。 (Example 2)
The same gear roll as in Example 1 was used for the second partial stretching process, except that the stretching direction of the second partial stretching process was 110 ° with respect to the stretching direction of the first partial stretching process. A laminated film sample of Example 2 was prepared in the same manner as in Example 1. In the film of Example 2, the distance between the convex portions of the concave-convex structure is 2.0 mm, and the films are arranged in a plurality of directions intersecting each other at 110 ° in the plane direction. The undulating structure is the same as in Example 1.

（実施例３）
第１回目の部分延伸加工の延伸方向に対して、第２回目の部分延伸加工の延伸方向を１３５°とした以外は、実施例２と同様にして、実施例３の積層フィルム試料を作製した。実施例３のフィルムは、凹凸構造の凸部の間隔は２．０ｍｍであり、平面方向に互いに１３５°で交差する複数方向に配列されている。起伏構造は、実施例１及び２と同様である。 (Example 3)
A laminated film sample of Example 3 was prepared in the same manner as in Example 2 except that the stretching direction of the second partial stretching process was set to 135 ° with respect to the stretching direction of the first partial stretching process. .. In the film of Example 3, the distance between the convex portions of the concave-convex structure is 2.0 mm, and the films are arranged in a plurality of directions intersecting each other at 135 ° in the plane direction. The undulating structure is the same as in Examples 1 and 2.

（比較例１）
実施例１における第２回目の部分延伸加工を行わず、一方向にのみ部分延伸を行った以外は、実施例１と同様にして、比較例１の積層フィルム試料を作製した。一方の面から他方の面に突出する積層構造の凸部は、平面方向に互いに交差する複数方向には配列していなかった。 (Comparative Example 1)
A laminated film sample of Comparative Example 1 was prepared in the same manner as in Example 1 except that the second partial stretching process in Example 1 was not performed and the partial stretching was performed in only one direction. The convex portions of the laminated structure protruding from one surface to the other were not arranged in a plurality of directions intersecting each other in the plane direction.

（比較例２）
実施例１で用いたものと同様の原料フィルムに対し、部分延伸ではなく全体を一方向に、延伸倍率２．０倍にして延伸し、比較例２の積層フィルム試料を作製した。一方の面から他方の面に突出する積層構造の凸部を複数、離間して配した凹凸構造（マクロな凹凸構造）は、出来なかった。 (Comparative Example 2)
The same raw material film as that used in Example 1 was stretched in one direction instead of being partially stretched at a stretch ratio of 2.0 times to prepare a laminated film sample of Comparative Example 2. It was not possible to create a concavo-convex structure (macro concavo-convex structure) in which a plurality of convex portions of a laminated structure protruding from one surface to the other surface were arranged at intervals.

（比較例３）
実施例１で用いたものと同様の原料フィルム全体に対する延伸加工を２回に分けて行った。第１回目の全体延伸加工の延伸方向に対して、第２回目の全体延伸加工の延伸方向を９０°として行った。第１回目及び第２回目の延伸倍率をいずれも１．８倍とした。このようにして原料フィルムに対し２回の全体延伸加工をして、比較例３の積層フィルム試料を作製した。一方の面から他方の面に突出する積層構造の凸部を複数、離間して配した凹凸構造（マクロな凹凸構造）は、出来なかった。 (Comparative Example 3)
The same stretching process as that used in Example 1 was performed on the entire raw material film in two steps. The stretching direction of the second total stretching process was set to 90 ° with respect to the stretching direction of the first total stretching process. The first and second draw ratios were set to 1.8 times. In this way, the raw material film was subjected to the whole stretching process twice to prepare the laminated film sample of Comparative Example 3. It was not possible to create a concavo-convex structure (macro concavo-convex structure) in which a plurality of convex portions of a laminated structure protruding from one surface to the other surface were arranged at intervals.

（比較例４）
炭酸カルシウム粒子を含有した直鎖状低密度ポリエチレンからなる単層の原料フィルムを用いて、実施例１と同様の部分延伸加工を行って、比較例４のフィルム試料を作製した。 (Comparative Example 4)
Using a single-layer raw material film made of linear low-density polyethylene containing calcium carbonate particles, the same partial stretching process as in Example 1 was performed to prepare a film sample of Comparative Example 4.

（比較例５）
実施例１で用いたものと同様の積層構造を有する原料フィルムを、延伸加工せずそのまま比較例５の積層フィルム試料とした。 (Comparative Example 5)
The raw material film having the same laminated structure as that used in Example 1 was used as it was as the laminated film sample of Comparative Example 5 without stretching.

（比較例６）
比較例５の積層フィルム試料と同様のものに、坪量８ｇ／ｍ^２のＳＭＳ（スパンボンド－メルトブローン－スパンボンド）不織布を積層して比較例６の積層フィルム試料とした。 (Comparative Example 6)
An SMS (spunbond-meltblown-spunbond) non-woven fabric having a basis weight of 8 g / m ² was laminated on the same sample as the laminated film sample of Comparative Example 5 to obtain a laminated film sample of Comparative Example 6.

上記の各試料に対して下記（１）～（５）の測定及び試験を行った。
（１）フィルム厚みの測定
各試料を５ｃｍ四方の大きさに調製し、０．０５ｋＰａの圧力がかかる状態で、フィルム厚みをレーザー変位計（キーエンス株式会社製）にて測定した。測定箇所は、サンプル平面内の５箇所で、その平均値を各試料のフィルム厚みとした。
（２）層厚みの測定
各試料について、前述の＜フィルムの層厚みの測定方法＞に記載の方法で、層厚みを測定した。
（３）曲げ剛性の測定
各試料を５ｃｍ四方の大きさに調製して４枚重ねにし、ハンドロメーター（ユニパルス株式会社製、型番：Ｆ３６０ＡＤＩＧＩＴＡＬＩＮＤＩＣＡＴＯＲ）を用いてフィルム中央部の曲げ剛性を測定した。その際、ハンドロメーターのスリット幅は３０ｍｍとした。
（４）肌触り官能評価試験
各試料を１０ｃｍ四方の大きさに調製したものを、ミクロな凹凸構造が上側に来るように平面に置き、パネル（サニタリー分野の研究に従事する者）５人に表面を指で撫でてもらった。撫でる強さと方向は指定しなかった。
始めに、不織布（ＳＭＳ不織布：８ｇ／ｍ^２）を触った時が１０点、原料フィルムとして用いた未加工フィルムを触った時が１点であることをパネルに伝え、すべての試料を触ってもらった後に、各試料の肌触りが不織布（ＳＭＳ不織布：８ｇ／ｍ^２）と原料フィルムとして用いた未加工フィルムのいずれかに近いかで、点数をつけてもらい評価した。評価点の平均値を各試料の肌触り官能評価の点数とした。
（５）外観官能評価試験
黒台紙の上に、各試料を１０ｃｍ四方の大きさに調製したものを、ミクロな凹凸構造が上側に来るように平面に置き、パネル（サニタリー分野の研究に従事する者）５人に外観を見てもらった。
始めに、無色透明なプラスチックフィルム（厚み１００μｍ、再生ＯＨＰフィルムＶＦ－１３００、コクヨ株式会社製、材質：ポリエチレンテレフタレート）の外観が１０点、穴あきの生じた部分延伸加工後のＬＤＰＥフィルム（厚み１２μｍ、延伸倍率２．７倍）の外観が１点であることをパネルに伝え、すべての試料を観てもらった後に、各試料の外観が無色透明なプラスチックフィルム（厚み１００μｍ）と穴あきの生じた部分延伸加工後のＬＤＰＥフィルム（厚み１２μｍ、延伸倍率２．７倍）のいずれかに近いかで、点数をつけてもらい評価した。評価点の平均値を各試料の外観官能評価の点数とした。
結果を表１に示す。 The following measurements and tests (1) to (5) were performed on each of the above samples.
(1) Measurement of film thickness Each sample was prepared to a size of 5 cm square, and the film thickness was measured with a laser displacement meter (manufactured by KEYENCE CORPORATION) under a pressure of 0.05 kPa. The measurement points were 5 points in the sample plane, and the average value was taken as the film thickness of each sample.
(2) Measurement of layer thickness For each sample, the layer thickness was measured by the method described in the above-mentioned <Measuring method of film layer thickness>.
(3) Measurement of flexural rigidity Measure the flexural rigidity of the central part of the film using a handrometer (manufactured by Unipulse Corporation, model number: F360A DIGITAL INDICATOR) after preparing each sample to a size of 5 cm square and stacking four sheets. did. At that time, the slit width of the handlometer was set to 30 mm.
(4) Touch sensory evaluation test Each sample was prepared to a size of 10 cm square and placed on a flat surface so that the micro-concave and convex structure was on the upper side, and the surface was applied to 5 panels (those engaged in research in the sanitary field). Was stroked with my finger. I did not specify the strength and direction of stroking.
First, tell the panel that when you touch the non-woven fabric (SMS non-woven fabric: 8 g / m ² ), you get 10 points, and when you touch the raw film used as the raw material film, you get 1 point, and touch all the samples. After receiving the film, each sample was evaluated based on whether the texture of each sample was close to that of the non-woven fabric (SMS non-woven fabric: 8 g / m ² ) or the unprocessed film used as the raw material film. The average value of the evaluation points was used as the score for the texture sensory evaluation of each sample.
(5) Appearance sensory evaluation test On a black mount, each sample prepared to a size of 10 cm square is placed on a flat surface so that the micro uneven structure is on the upper side, and engaged in research in the panel (sanitary field). Person) Five people looked at the appearance.
First, the appearance of a colorless and transparent plastic film (thickness 100 μm, recycled OHP film VF-1300, manufactured by KOKUYO Co., Ltd., material: polyethylene terephthalate) is 10 points, and the LDPE film after partial stretching with holes (thickness 12 μm, After informing the panel that the appearance of the draw ratio (2.7 times) is one point and having all the samples viewed, the appearance of each sample is a colorless transparent plastic film (thickness 100 μm) and the perforated part. The film was evaluated based on whether it was close to any of the stretched LDPE films (thickness 12 μm, draw ratio 2.7 times). The average value of the evaluation points was used as the score for the appearance and sensory evaluation of each sample.
The results are shown in Table 1.

表１に示す通り、比較例２及び３の試料は、全体延伸して凹凸構造を設けなかったものであり、フィルム厚みが４０μｍ及び７０μｍであった。これに対し、実施例１～３の試料は、比較例２及び３の試料と同等の坪量であるにも関わらず、２．５倍以上のフィルム厚みを有していた。また、実施例１～３の試料は、一方向にのみ部分延伸した比較例１のものよりもフィルム厚みを有し、実施例１～３よりも坪量の大きい比較例６と同等またはそれ以上のフィルム厚みを有していた。さらに、実施例１～３は、比較例１～５の試料よりもふっくらした触感を感じられるものであった。
実施例１～３の試料は、Ｈ１がＨ２よりも小さく、より柔らかく感じることができるものであった。一方で、延伸倍率が低かった比較例２及び３、単層フィルムを用いた比較例４、並びに延伸加工を行わなかった比較例５及び６の試料では、フィルムに起伏構造（ミクロな凹凸構造）が現れず、Ｈ１及びＨ２を測定できなかった。
実施例１～３の試料は、一方向にのみ部分延伸した比較例１のものよりも曲げ剛性が低く、同等のフィルム厚みのある比較例６の試料の曲げ剛性の４割以下であり、柔らかいものであることが分かった。また、実施例１～３は、同等の坪量を有する比較例５よりも曲げ剛性が低く、柔らかいものであることが分かった。一方で、比較例４の試料は、二方向に部分延伸しているにもかからず、単層フィルムからなるため曲げ剛性が８ｇｆ／ｃｍで、直ぐにしわになってしまい、保形性が足りないものであった。これに対し、実施例１～３は、積層フィルムを二方向に部分延伸したもので、約２倍の曲げ剛性を有し、適度な保形性、耐久性を有していた。
実施例１～３は、同等の坪量を有する比較例１～３よりも肌触り官能評価の点数が高く、実際に触れた際に柔らかく感じられるものであることが分かった。また、実施例１～３は、同等の坪量を有する比較例２及び３の試料よりも、また不織布と積層フィルムとを重ねた比較例６の試料よりも外観官能評価の点数が高かった。
以上のことから、実施例１～３は、フィルム厚み、曲げ剛性、肌触り官能評価及び外観官能評価の全ての項目において、比較例１～６よりも優れていることが分かった。 As shown in Table 1, the samples of Comparative Examples 2 and 3 were entirely stretched and did not have an uneven structure, and the film thicknesses were 40 μm and 70 μm. On the other hand, the samples of Examples 1 to 3 had a film thickness of 2.5 times or more, although they had the same basis weight as the samples of Comparative Examples 2 and 3. Further, the samples of Examples 1 to 3 have a film thickness larger than that of Comparative Example 1 partially stretched only in one direction, and are equal to or larger than those of Comparative Example 6 having a larger basis weight than Examples 1 to 3. Had a film thickness of. Further, in Examples 1 to 3, a fluffier tactile sensation was felt as compared with the samples of Comparative Examples 1 to 5.
In the samples of Examples 1 to 3, H1 was smaller than H2 and could be felt softer. On the other hand, in the samples of Comparative Examples 2 and 3 having a low draw ratio, Comparative Example 4 using a single-layer film, and Comparative Examples 5 and 6 not subjected to the stretching process, the film had an undulating structure (micro uneven structure). Did not appear, and H1 and H2 could not be measured.
The samples of Examples 1 to 3 have lower bending rigidity than those of Comparative Example 1 partially stretched in only one direction, and are 40% or less of the bending rigidity of the sample of Comparative Example 6 having the same film thickness, and are soft. It turned out to be a thing. Further, it was found that Examples 1 to 3 had lower bending rigidity and were softer than Comparative Example 5 having the same basis weight. On the other hand, although the sample of Comparative Example 4 is partially stretched in two directions, it is made of a single-layer film and has a flexural rigidity of 8 gf / cm. It wasn't. On the other hand, in Examples 1 to 3, the laminated film was partially stretched in two directions, had about twice the bending rigidity, and had appropriate shape retention and durability.
It was found that Examples 1 to 3 had a higher score of the touch sensory evaluation than Comparative Examples 1 to 3 having the same basis weight, and felt soft when actually touched. In addition, Examples 1 to 3 had higher scores for appearance and sensory evaluation than the samples of Comparative Examples 2 and 3 having the same basis weight and the sample of Comparative Example 6 in which the non-woven fabric and the laminated film were laminated.
From the above, it was found that Examples 1 to 3 were superior to Comparative Examples 1 to 6 in all the items of film thickness, flexural rigidity, touch sensory evaluation and appearance sensory evaluation.

１弾性層
２塑性層
３凸部
４凹部
５凹凸構造（マクロな凹凸構造）
６連結部
７起伏構造（ミクロな凹凸構造）
７１溝
７２凸条部
１０積層フィルム

1 Elastic layer 2 Plastic layer 3 Convex part 4 Concave part 5 Concavo-convex structure (macro concavo-convex structure)
6 Connecting part 7 Undulating structure (micro uneven structure)
71 Groove 72 Convex 10 Laminated film

Claims

A film having a laminated structure having an elastic layer and a plastic layer and having the plastic layer as the outermost surface.
The film has a concavo-convex structure in which a plurality of convex portions of the laminated structure projecting from one surface to the other surface are spaced apart and arranged in a plurality of directions intersecting each other in a planar direction, and the convex portions are arranged. The ratio (W1 / W2) of the length (W1) of the convex portion in the direction to the width (W2) of the connecting portion sandwiched between the convex portions in the arrangement direction in the arrangement direction is 0.5 or more 1. 0.8 or less,
The connecting portions between the convex portions are arranged in a grid pattern so as to partition the convex portions, and are whitened by holes that scatter transmitted light.
An undulating structure having a height difference smaller than that of the uneven structure is arranged on the surface of the laminated structure at least in the connecting portion.
A laminated film in which the undulating structure has a ridge extending in one direction in the plane direction and another ridge extending in a different direction intersecting the one direction.

The laminated film according to claim 1, wherein the convex portion has a portion protruding in the opposite direction to the plane of the film.

The laminated film according to claim 1 or 2, wherein the plastic layer contains calcium carbonate.

An absorbent article having a front surface sheet, a back surface sheet, and an absorber sandwiched between these sheets, wherein the laminated film according to any one of claims 1 to 3 is used as the back surface sheet. An absorbent article in which a layer is exposed on the back surface of the absorbent article.

A raw material film having a laminated structure having an elastic layer and a plastic layer and having the plastic layer as the outermost surface is sandwiched between a pair of gear rolls having teeth and grooves that mesh with each other, and the facing teeth and the grooves are loosened. It has a step of inserting and partially stretching in two directions.
By the step of partially stretching, a plurality of convex portions of the laminated structure protruding from one surface to the other surface are separated from each other to form a concavo-convex structure in which they are arranged in a plurality of directions intersecting each other in a plane direction. The ratio (W1 / W2) of the length (W1) of the convex portion in the arrangement direction of the portions to the width (W2) of the connecting portion sandwiched between the convex portions in the arrangement direction in the arrangement direction is 0. In the step of 5 or more and 1.8 or less, the connecting portion between the convex portions is formed in a grid pattern so as to partition the convex portions, and holes for scattering transmitted light are formed in the connecting portion. A step of whitening and stretching with plastic deformation are added to the plastic layer, and the plastic layer shrinks with the shrinkage of the elastic layer after the partial stretching to form an undulating structure having a smaller height difference than the uneven structure. A convex portion formed on the surface of the laminated structure at least in the connecting portion and extending in one direction in the plane direction and another convex portion extending in a different direction intersecting the one direction in the undulating structure. A method for manufacturing a laminated film, which comprises the steps of forming the laminated film.