JPH0149112B2

JPH0149112B2 -

Info

Publication number: JPH0149112B2
Application number: JP59054998A
Authority: JP
Inventors: Hideo Shibata; Junpei Yamazaki
Original assignee: Sekisui Plastics Co Ltd
Current assignee: Sekisui Kasei Co Ltd
Priority date: 1984-03-21
Filing date: 1984-03-21
Publication date: 1989-10-23
Also published as: JPS60198231A

Description

[Detailed description of the invention]

本発明は生理用品、壁紙、農水産物、食品など
に用いられる吸水・保水シートとして好適な吸水
性積層発泡シートに関する。近年、生理用品、おもつはもとより、住宅用壁
材、天井板、農業用保水シート、肉用トレー、果
実用パツクシートなどにあつては、吸水・保水性
を付与して、結露等やそれに伴う被覆内容物の品
質低下を防ぎ、商品価値を高めることが必要とさ
れている。そして、従来、壁材や天井板は木材や
土壁など適度な吸水性をもつ材料で作られていた
が、これらは保温性、軽量化に難があり、コスト
高となるため、その多くが他の材料に代替され、
また、現在の用途上からすると吸水性が非常に低
いという欠点があつた。また果実用パツクシート
としてパルプの吸水性を利用したシートが知られ
ているが、かかるシートの吸水能力を高めるには
坪量を大きく、しかも厚くしなければならないと
いう欠点があつた。一方、近年ではデンプン−アクリル酸塩グラフ
ト重合体、架橋ポリアクリル酸塩等の水不溶性
で、高吸水・保水能力を有す吸水性樹脂が開発さ
れているが、これらは殆んど粉末か液体状である
ため、それ以外の形にすることができず、積層シ
ート化が困難であつた。すなわち、吸水シートの
間、あるいは吸水シートと水不透過性シートとの
間に、これら高吸水性樹脂粉末をサンドイツチし
たものや、水不溶性の基材に高吸水性樹脂の溶液
をスプレー、塗布、含浸して乾燥させたものは、
表裏シートの破損や使用中に、高吸水性樹脂粉末
や吸水膨潤した高吸水性樹脂が露呈、脱落するだ
けでなく、また成型性がない等の欠点があつた。本発明者らは、これらの問題点を解決すべく、
鋭意研究した結果、高吸水性樹脂を接着性樹脂に
混和した接着層を用いて積層した積層体が、接着
性樹脂だけを用いて積層したものに比べ、吸水・
保水能力が著しく大きく、しかも上記欠点がない
ことを見い出し、本発明を完成するに至つた。す
なわち、本発明に係る吸水性積層体の要旨とする
ところは親水性・通水性多孔シートと、合成樹脂
発泡シートとが、高吸水性樹脂と接着性樹脂とか
らなる接着層を介して積層された吸水性積層体に
ある。以下に、本発明に係る吸水性積層体の内容を図
面に基づいて説明する。図において、１は親水性・通水性多孔シート、
３は高吸水性樹脂４と接着性樹脂とからなる接着
層、６は合成樹脂発泡シートを示す。本発明に係る吸水性積層体に用いる親水性・通
水性多孔シート１は、該シート１表面により裏
面、すなわち、接着層３により接着される面、に
通じる多数の穴や連通孔２を有するシートであ
り、かかる穴や連通孔２を通じて、接着層３中の
高吸水性樹脂４により、水分が吸収・保水され
る。そして、該穴や連通孔２の径は、接着時、又
はその後、高吸水性樹脂４が、該穴等を塞ぐこと
がないよう、高吸水性樹４により径小である。かかる親水性・通水性多孔シート１の具体例と
しては、不織布や、SBS（Solid Bleak Sulfate）
と呼ばれる長繊維の紙や、親水化したポリエチレ
ン、ポリプロピレン等の通水性多孔シート等があ
る。また、合成樹脂発泡シート６は、合成樹脂を押
出し発泡、ビーズ発泡等の手段で発泡させ、シー
ト化あるいは板状化して、断熱保温性を付与した
ものである。そして、合成樹脂発泡シート６は、
接着層３中の高吸水性樹脂により、吸水、保水さ
れた水分の逃散を防止するため、疎水性で、耐水
性に富むものが好適である。かかる合成樹脂発泡
シートとしては、ポリエチレン、ポリプロピレ
ン、ポリ塩化ビニルなど各種の合成樹脂の発泡シ
ートが挙げられるが、二次加工性等を考慮する
と、強度、成形性に優れたスチレン系樹脂の発泡
シートが好ましい。スチレン系樹脂発泡シートと
しては、スチレン単独重合体樹脂に限らず、スチ
レンを主成分とし、スチレンと共重合し得るモノ
マーとの共重合体樹脂、例えば、ハイインパクト
ポリスチレン、スチレン−アクリロニトリル共重
合体樹脂、スチレン−ブタジエン共重合体樹脂、
スチレン−ブタジエン−アクリロニトリル共重合
体樹脂等の樹脂の発泡シートを挙げることができ
る。尚、発泡、シート化あるいは板状化は、通常の
方法、例えば上記樹脂に発泡剤を混和し、発泡さ
せた後、スライス等の手段で行なうことが出来、
また、合成樹脂発泡シートの発泡倍率は、用途等
に応じ適宜変えることができる。かかる親水性・通水性多孔シート１と合成樹脂
発泡シート６とは、高吸水性樹脂４と接着性樹脂
とからなる接着層３により互いに接着・積層さ
れ、本発明に係る吸水性積層体が得られる。該接着層３は、高吸水性樹脂４を接着性樹脂に
混合、分散させたもので、かかる接着層３の高吸
水性樹脂４としては、デンプン−アクリル酸塩グ
ラフト重合体、架橋ポリアクリル酸塩ポリビニル
アルコール架橋重合体、デンプン−アクリロニト
リルグラフト重合体等の水不溶性で、吸水能力が
大きい高吸水性樹脂である。これらの形態は溶液
状であつてもよいが、好適には粉末状のものであ
る。これらは、単独、もしくは２種以上混合して
使用される。また、接着性樹脂としては、天然ゴムあるいは
ポリブタジエン、ポリイソプレン、スチレン、−
ブタジエン共重合体、スチレン−イソプレン共重
合体、ポリウレタン樹脂等の熱可塑性合成ゴム、
またはエチレン−酢酸ビニル共重合体等があげら
れ、接着強度、靭性等の特性が優れたものであ
る。これらの接着性樹脂は単独もしくは、２種以上
混合して用いてもよく、また、これら樹脂と相溶
性の良い他の熱可塑性樹脂（例えば、ポリエチレ
ンなど）とを、接着性樹脂100部に対し、２〜100
部混和し使用してもよい。更には、これら熱可塑
性の接着性樹脂には、必要に応じて、プラスチツ
ク用添加剤、例えば顔料タルク、紫外線吸収剤、
発泡剤などを接着性が落ちず、シートが容易に剥
離しない程度にまで添加してもよい。かかる高吸水性樹脂と接着性樹脂の使用量は熱
可塑性の接着性樹脂100部に対して、高吸水性樹
脂が少くとも２重量部以上、好ましくは５重量部
以上で、100重量部以下である。２重量部以下で
は、吸水能力が低く、また100重量部以上では吸
水時の体積膨張により生ずるストレスを緩和する
ためには、接着層に、より多くの孔等を設ける必
要があり、また、接着力も十分でない。そして、かかる組成の接着層は、カレンダーロ
ールや押出機等を用いて、シート化し、該シート
を積層することが、作業上好適である。また高吸水性樹脂による吸水効率を高めると共
に吸水時の体積膨張に伴い生ずるストレスを緩和
するためには、発泡剤による連通化や溶出法及び
延伸法など公知の手段を用いて、シート化された
接着層３は、多数の孔５を有するように、多孔化
されたものが好ましい。かかる接着層と、親水性・通水性多孔シート、
合成樹脂発泡シートとの積層方法としては、組み
合せる各層の種類に応じて、ドライラミネートに
よる積層、２層コエクストルージヨンによるシー
ト化後、ドライラミネートによる積層、３層コエ
クストルージヨンによる積層等適宜選択し得る。尚、本発明に係る吸水性積層体は上記構造のも
のに限定されるものではなく、必要に応じて合成
樹脂発泡シートの両面に接着層を介して、親水
性・通水性多孔シートを積層したものであつても
よい。このようにして得られた本発明に係る吸水性積
層体は、親水性・通水性多孔シートが吸水・保水
性を有すのみならず、高吸水性樹脂を接着性樹脂
中に混和した接着層が著しく大きな吸水・保水性
を有するため、シート周辺の環境条件に応じて、
親水性・通水性多孔シートの多数の孔を介して、
高吸水性樹脂が可逆的、かつ速やかに水分を吸
水・放散する。特に、接着層を多孔化したシート
にあつては、高吸水性樹脂が該孔に直接接してい
るため、水分の吸水・放散は、より速やかとな
る。しかも、接着層中の高吸水性樹脂との混合比
率を広範囲にわたり可変することが出来、また接
着層を厚くすることも薄くすることも出来るた
め、吸水性積層体の吸水・保水能力を調整でき、
用途に応じた適度な吸水・保水性をもつシートが
得られる。また、接着性が大きい接着性樹脂中に高吸水性
樹脂を分散しているため、高吸水性樹脂が積層体
から脱落することがない。更には、強靭で弾力
性、可撓性等が優れた熱可塑性ゴムや、エチレン
−酢酸ビニル共重合体等は、高吸水性樹脂の吸水
膨張等に伴い生ずるストレスを迅速に緩和するた
め、親水性・通水性多孔シートとスチレン系樹脂
発泡シートは剥離することなく、接着層で強固に
接着され、また、吸水膨潤時においても保形性を
有する。特に接着層を多孔化したものではその効
果が大きい。更には、疎水性で耐水性に優れた合成樹脂発泡
シートを用いているため水分のシート裏面からの
漏出がなく、高吸水性樹脂による吸水・保水能力
を高める効果がある。また、適度な剛性、高い耐水性、吸水しても保
持する断熱性、真空成型等による二次加工性だけ
でなく、薄層化、軽量化できるという利点をも兼
せ持つ。そして、本発明に係る吸水性積層体は生理用
品、おむつ、断熱性壁紙、天井材や農水産物のパ
ツクシート、食品トレー等に適用することがで
き、結露水や余分な水分を吸収したり、乾燥を防
止することができる。以下に本発明に係る吸水性積層体の実施例を示
す。実施例１アクリル酸とビニルアルコール共重合体を主と
した高吸水性樹脂（住友化学工業(株)製商品名スミ
カゲルＳ−50）10部と接着性樹脂であるエチレン
酢酸ビニル共重合体（住友化学工業(株)社製、商品
名エバテートH2011）100部とをカレンダーロー
ルにてシート化し、２軸延伸にて多孔化した0.05
mmの接着層であるシートを作成した。また、親水
性・通水性多孔シートとして、厚さ0.1mmの親水
性ポリプロピレン多孔シート（積水化学社製商品
名セルポア）を用い、合成樹脂発泡シートとし
て、密度0.2ｇ／cm³、厚さ１mmの発泡ポリスチレ
ンシートを用いた。かかる親水性・通水性多孔シート、合成樹脂発
泡シート及びシート化した接着層をドライラミネ
ート法により、接着層を中間層とする本発明に係
る吸水性積層体を得た。こうして得られた積層体
の吸水量等の試験結果を表１に示す。実施例２ポリアクリル酸ソーダ架橋体を主とした高吸水
性樹脂（製鉄化学社製商品名アクアキープ10S）
５部と接着性樹脂であるエチレン・酢酸ビニル共
重合体（前掲）100部とをカレンダーロールにて、
シート化し、その後延伸処理を施さずに孔のない
厚さ0.05mmの接着層であるシートを作成する以外
は実施例１と同様にして、本発明に係る吸水性積
層体を得た。このようにして得られた積層体の吸
水量等の試験結果を表１に示す。実施例３高吸水性樹脂であるアクアキープ10S（前掲）
20部と、接着性樹脂であるスチレン・ブタジエン
共重合体100部とをカレンダーロールにて、シー
ト化し、２軸延伸にて多孔化した厚さ0.05mmの接
着層であるシートを作成した。また親水性・通水
性多孔シートとして40ｇ／m²の不織布（金星製紙
社製）を用い、合成樹脂発泡シートとして密度が
0.1ｇ／cm³、厚さ2.0mmの発泡ポリスチレンシート
を用い、実施例１と同様にして本発明に係る吸水
性積層体を得た。このようにして得られた積層体
の吸水性等の試験結果を表１に示す。比較例１接着層であるシートとして、厚さ0.05mmのエチ
レン・酢酸ビニル共重合体（前掲）を用いる以外
は、実施例１と同様にして、高吸水性樹脂を含有
しない積層体を得た。比較例２親水性・通水性多孔シートに代えて厚さ0.05mm
の疎水性ポリエチレンシートを用い、合成樹脂発
泡シートとして、密度0.2ｇ／cm³、厚さ１mmの発
泡ポリスチレンシート、接着層シートとして、厚
さ0.05mmのエチレン酢酸ビニル共重合体（前掲）
を用い、実施列１と同様にして高吸水性樹脂を含
有せず、しかも、多孔を有さないポリエチレンシ
ートを表層に設けた積層体を得た。このようにして得られた積層体の吸水性等の試
験結果を、上記実施例１〜３の本発明に係る吸水
性積層体の試験結果と比較して表１に示す。 The present invention relates to a water-absorbing laminated foam sheet suitable as a water-absorbing/water-retaining sheet for use in sanitary products, wallpaper, agricultural and marine products, foods, and the like. In recent years, in addition to sanitary products and omotsu, wall materials for housing, ceiling panels, water-retaining sheets for agriculture, trays for meat, and packing sheets for fruit have been given water-absorbing and water-retaining properties to prevent condensation and other condensation. It is necessary to prevent the quality of the coated contents from deteriorating and increase the commercial value. Traditionally, wall materials and ceiling panels have been made of materials with moderate water absorption, such as wood and clay walls, but these have difficulty retaining heat and reducing weight, and are expensive, so many of them are substituted with other materials,
In addition, from the viewpoint of current uses, it has a drawback of extremely low water absorption. In addition, sheets that utilize the water absorbing properties of pulp are known as fruit pack sheets, but these sheets have the disadvantage that they must have a large basis weight and be thick in order to increase their water absorbing ability. On the other hand, in recent years, water-insoluble water-absorbing resins such as starch-acrylate graft polymers and cross-linked polyacrylates with high water absorption and water retention abilities have been developed, but most of these are powders or liquids. Because of its shape, it could not be made into any other shape, and it was difficult to form it into a laminated sheet. That is, between the water-absorbing sheets or between the water-absorbing sheet and the water-impermeable sheet, these super-absorbent resin powders are sandwiched, or a super-absorbent resin solution is sprayed or applied to a water-insoluble base material. The impregnated and dried
When the front and back sheets are damaged or during use, the super-absorbent resin powder and the super-absorbent resin that has swelled with water are exposed and fall off, and there are also drawbacks such as lack of moldability. In order to solve these problems, the present inventors
As a result of extensive research, we found that laminates laminated using an adhesive layer containing a super absorbent resin mixed with an adhesive resin have better water absorption and
The present inventors have discovered that the water retention capacity is extremely high and that they do not have the above-mentioned drawbacks, leading to the completion of the present invention. That is, the gist of the water absorbent laminate according to the present invention is that a hydrophilic/water permeable porous sheet and a synthetic resin foam sheet are laminated with an adhesive layer made of a super absorbent resin and an adhesive resin interposed therebetween. It is a water-absorbent laminate. Below, the contents of the water absorbent laminate according to the present invention will be explained based on the drawings. In the figure, 1 is a hydrophilic/water permeable porous sheet;
Reference numeral 3 indicates an adhesive layer made of super absorbent resin 4 and adhesive resin, and reference numeral 6 indicates a synthetic resin foam sheet. The hydrophilic/water-permeable porous sheet 1 used in the water-absorbing laminate according to the present invention is a sheet having a large number of holes or communicating holes 2 that connect the front surface of the sheet 1 to the back surface, that is, the surface bonded by the adhesive layer 3. Through these holes and communication holes 2, water is absorbed and retained by the super absorbent resin 4 in the adhesive layer 3. The diameter of the hole or communication hole 2 is made small by the super-absorbent resin 4 so that the super-absorbent resin 4 does not block the hole etc. during or after bonding. Specific examples of such a hydrophilic/water permeable porous sheet 1 include nonwoven fabric and SBS (Solid Bleak Sulfate).
There are long-fiber paper called 3-fiber paper, water-permeable porous sheets made of hydrophilic polyethylene, polypropylene, etc. Further, the synthetic resin foam sheet 6 is made by foaming a synthetic resin by extrusion foaming, bead foaming, or the like, and forming it into a sheet or plate shape to provide heat insulation and heat retention. The synthetic resin foam sheet 6 is
In order to prevent water absorbed and retained by the superabsorbent resin in the adhesive layer 3 from escaping, it is preferably hydrophobic and highly water resistant. Examples of such foamed synthetic resin sheets include foamed sheets of various synthetic resins such as polyethylene, polypropylene, and polyvinyl chloride, but when considering secondary processability, foamed sheets of styrene resin with excellent strength and moldability are preferred. is preferred. Styrenic resin foam sheets are not limited to styrene homopolymer resins, but also copolymer resins containing styrene as a main component and monomers that can be copolymerized with styrene, such as high impact polystyrene, styrene-acrylonitrile copolymer resins, etc. , styrene-butadiene copolymer resin,
Examples include foamed sheets of resins such as styrene-butadiene-acrylonitrile copolymer resins. Note that foaming, forming into a sheet, or forming into a plate can be carried out by a usual method, for example, by mixing a foaming agent with the above resin, foaming it, and then slicing.
Further, the foaming ratio of the synthetic resin foam sheet can be changed as appropriate depending on the use and the like. The hydrophilic/water permeable porous sheet 1 and the synthetic resin foam sheet 6 are adhered and laminated to each other by an adhesive layer 3 made of a super absorbent resin 4 and an adhesive resin to obtain a water absorbent laminate according to the present invention. It will be done. The adhesive layer 3 is made by mixing and dispersing a super absorbent resin 4 in an adhesive resin, and the super absorbent resin 4 of the adhesive layer 3 includes starch-acrylate graft polymer, crosslinked polyacrylic acid Water-insoluble and highly water-absorbent resins such as salt polyvinyl alcohol cross-linked polymers and starch-acrylonitrile graft polymers, which have a large water-absorbing capacity. Although these forms may be in the form of a solution, they are preferably in the form of a powder. These may be used alone or in combination of two or more. In addition, adhesive resins include natural rubber, polybutadiene, polyisoprene, styrene, -
Thermoplastic synthetic rubbers such as butadiene copolymers, styrene-isoprene copolymers, polyurethane resins,
Alternatively, ethylene-vinyl acetate copolymer may be mentioned, which has excellent properties such as adhesive strength and toughness. These adhesive resins may be used alone or in a mixture of two or more, and other thermoplastic resins having good compatibility with these resins (for example, polyethylene) may be added to 100 parts of the adhesive resin. , 2-100
You may also mix them together and use them. Furthermore, these thermoplastic adhesive resins may contain additives for plastics, such as pigment talc, ultraviolet absorbers,
A foaming agent or the like may be added to the extent that the adhesiveness does not deteriorate and the sheet does not peel off easily. The amount of super absorbent resin and adhesive resin to be used is at least 2 parts by weight or more, preferably 5 parts by weight or more, and 100 parts by weight or less per 100 parts of thermoplastic adhesive resin. be. If it is less than 2 parts by weight, the water absorption capacity will be low, and if it is more than 100 parts by weight, it will be necessary to provide more holes in the adhesive layer in order to alleviate the stress caused by volumetric expansion when water is absorbed. There's not enough power either. It is suitable for work to form the adhesive layer having such a composition into a sheet using a calendar roll, an extruder, etc., and then laminate the sheets. In addition, in order to increase the water absorption efficiency of the superabsorbent resin and to alleviate the stress caused by volumetric expansion when water is absorbed, the resin is made into a sheet using known means such as communication using a foaming agent, elution method, and stretching method. The adhesive layer 3 is preferably porous so that it has a large number of holes 5. Such an adhesive layer, a hydrophilic/water permeable porous sheet,
Depending on the type of each layer to be combined, lamination methods with synthetic resin foam sheets include dry lamination, two-layer co-extrusion to form a sheet, dry lamination, three-layer co-extrusion, etc. It can be selected as appropriate. The water-absorbing laminate according to the present invention is not limited to the structure described above, and if necessary, a hydrophilic and water-permeable porous sheet may be laminated on both sides of a synthetic resin foam sheet via an adhesive layer. It may be something. The water-absorbing laminate according to the present invention obtained in this manner not only has a hydrophilic and water-permeable porous sheet that has water-absorbing and water-retaining properties, but also has an adhesive layer in which a super-absorbent resin is mixed into an adhesive resin. has extremely high water absorption and water retention properties, so depending on the environmental conditions around the sheet,
Through the many pores of the hydrophilic/water permeable porous sheet,
Super absorbent resin absorbs and releases moisture reversibly and quickly. In particular, in the case of a sheet in which the adhesive layer is made porous, since the superabsorbent resin is in direct contact with the pores, water absorption and dissipation are more rapid. Moreover, the mixing ratio of the superabsorbent resin in the adhesive layer can be varied over a wide range, and the adhesive layer can be made thicker or thinner, so the water absorption and water retention capacity of the water absorbent laminate can be adjusted. ,
A sheet with appropriate water absorption and water retention properties can be obtained depending on the application. Furthermore, since the super absorbent resin is dispersed in the adhesive resin with high adhesive properties, the super absorbent resin does not fall off from the laminate. Furthermore, thermoplastic rubbers that are strong, have excellent elasticity, and flexibility, and ethylene-vinyl acetate copolymers are hydrophilic to quickly relieve the stress that occurs when superabsorbent resins expand upon water absorption. The permeable and water permeable porous sheet and the styrene resin foam sheet are firmly adhered to each other by an adhesive layer without peeling, and also retain their shape even when they absorb water and swell. This effect is particularly great when the adhesive layer is made porous. Furthermore, since a synthetic resin foam sheet that is hydrophobic and has excellent water resistance is used, there is no leakage of moisture from the back surface of the sheet, which has the effect of increasing the water absorption and water retention ability of the super absorbent resin. In addition, it has the advantages of moderate rigidity, high water resistance, heat insulation that retains water even when it absorbs water, and secondary processability through vacuum forming, etc., as well as being able to be made thinner and lighter. The water-absorbing laminate according to the present invention can be applied to sanitary products, diapers, insulating wallpaper, ceiling materials, pack sheets for agricultural and marine products, food trays, etc., and can absorb condensation water and excess water, dry can be prevented. Examples of the water absorbent laminate according to the present invention are shown below. Example 1 10 parts of a super absorbent resin mainly composed of acrylic acid and vinyl alcohol copolymer (product name: Sumikagel S-50, manufactured by Sumitomo Chemical Co., Ltd.) and ethylene vinyl acetate copolymer (trade name, manufactured by Sumitomo Chemical Co., Ltd.), which is an adhesive resin. 100 parts of Evatate H2011 (manufactured by Kagaku Kogyo Co., Ltd.) was formed into a sheet using a calendar roll, and made porous by biaxial stretching.
A sheet with an adhesive layer of mm was created. In addition, a hydrophilic polypropylene porous sheet (trade name: Cellpore, manufactured by Sekisui Chemical Co., Ltd.) with a thickness of 0.1 mm was used as the hydrophilic/water permeable porous sheet, and a synthetic resin foam sheet with a density of 0.2 g/cm ³ and a thickness of 1 mm was used. A foamed polystyrene sheet was used. A water-absorbing laminate according to the present invention having the adhesive layer as an intermediate layer was obtained by dry laminating the hydrophilic/water-permeable porous sheet, the foamed synthetic resin sheet, and the sheeted adhesive layer. Table 1 shows test results such as water absorption of the thus obtained laminate. Example 2 Super water-absorbent resin mainly composed of cross-linked polysodium acrylate (trade name: Aqua Keep 10S, manufactured by Steel Chemical Co., Ltd.)
5 parts and 100 parts of the adhesive resin ethylene/vinyl acetate copolymer (listed above) using a calendar roll.
A water-absorbing laminate according to the present invention was obtained in the same manner as in Example 1, except that the sheet was formed into a sheet and then a sheet with a 0.05 mm thick adhesive layer without holes was created without performing any stretching treatment. Table 1 shows test results such as the water absorption amount of the laminate thus obtained. Example 3 Aqua Keep 10S, a super absorbent resin (mentioned above)
20 parts of the adhesive resin and 100 parts of styrene-butadiene copolymer, which is an adhesive resin, were formed into a sheet using a calendar roll, and biaxially stretched to create a porous adhesive layer sheet with a thickness of 0.05 mm. In addition, a 40g/ ^m2 nonwoven fabric (manufactured by Kinsei Paper Industries) was used as a hydrophilic and water permeable porous sheet, and a synthetic resin foam sheet with a density of 40g/m2 was used.
A water-absorbing laminate according to the present invention was obtained in the same manner as in Example 1 using a foamed polystyrene sheet having a density of 0.1 g/cm ³ and a thickness of 2.0 mm. Table 1 shows the test results of the water absorbency, etc. of the laminate thus obtained. Comparative Example 1 A laminate containing no superabsorbent resin was obtained in the same manner as in Example 1, except that a 0.05 mm thick ethylene/vinyl acetate copolymer (described above) was used as the adhesive layer sheet. . Comparative example 2 0.05mm thick instead of hydrophilic/water permeable porous sheet
A hydrophobic polyethylene sheet with a density of 0.2 g/cm ³ and a thickness of 1 mm was used as the synthetic resin foam sheet, and an ethylene-vinyl acetate copolymer with a thickness of 0.05 mm (as described above) was used as the adhesive layer sheet.
Using this method, a laminate was obtained in the same manner as in Example 1, in which a polyethylene sheet containing no superabsorbent resin and having no pores was provided on the surface layer. The test results of the water absorbency etc. of the thus obtained laminate are shown in Table 1 in comparison with the test results of the water absorbent laminate according to the present invention in Examples 1 to 3 above.

【表】上記から明らかなように、接着層に高吸水性樹
脂を含有しない積層体に比べ、本発明に係る吸水
性積層体の吸水量は、接着層を多孔化しないもの
（実施例２）でも約100ｇ／m²を示し、接着層を多
孔化することにより、吸水量は約２倍大きくな
り、また、高吸水性樹脂の量が多くなるに従が
い、吸水量は著しく大きくなる（実施例３）。尚、比較例１の積層体は、55ｇ／m²の吸水量を
示しているが、これは、シート表層の親水性・通
水性多孔シートによる吸水性に基づくものであ
る。また、本発明に係る吸水性積層体は、１時間吸
水後、いずれもシートが剥離したり、高吸水性樹
脂がシートから脱落することはなかつた。[Table] As is clear from the above, the water absorption amount of the water absorbent laminate according to the present invention is higher than that of the laminate that does not contain a superabsorbent resin in the adhesive layer (Example 2) However, it shows approximately 100g/ ^m2 , and by making the adhesive layer porous, the water absorption amount increases approximately twice as much, and as the amount of superabsorbent resin increases, the water absorption amount increases significantly (implemented). Example 3). The laminate of Comparative Example 1 has a water absorption of 55 g/m ² , which is based on the water absorption of the hydrophilic and water-permeable porous sheet in the sheet surface layer. Further, in the water-absorbing laminates according to the present invention, the sheets did not peel off or the superabsorbent resin did not fall off from the sheets after 1 hour of water absorption.

[Brief explanation of drawings]

第１図は、本発明に係る吸水性積層体の一部欠
載斜視図、第２図は、その拡大断面図を示す。符号の説明、１……親水性・通水性多孔シー
ト、２……連通孔、３……接着層、４……高吸水
性樹脂粉末、５……孔、６……合成樹脂発泡シー
ト。 FIG. 1 is a partially cutaway perspective view of a water absorbent laminate according to the present invention, and FIG. 2 is an enlarged sectional view thereof. Explanation of the symbols: 1... Hydrophilic/water permeable porous sheet, 2... Communication hole, 3... Adhesive layer, 4... Super water absorbent resin powder, 5... Hole, 6... Synthetic resin foam sheet.

Claims

[Claims] 1. A water-absorbing laminate characterized in that a hydrophilic/water-permeable porous sheet and a synthetic resin foam sheet are laminated via an adhesive layer made of a super-absorbent resin and an adhesive resin. body. 2. The water-absorbing laminate according to claim 1, wherein the hydrophilic/water-permeable porous sheet is a water-permeable porous sheet of nonwoven fabric, paper, or hydrophilized polyethylene, polypropylene, or the like. 3. The water-absorbing laminate according to claim 1, wherein the synthetic resin foam sheet is a styrene resin foam sheet. 4. The styrenic resin foam sheet according to claim 1 or 3, wherein the styrene resin foam sheet is a foam sheet of a styrene homopolymer or a copolymer containing styrene as a main component and a monomer copolymerizable with styrene. Water absorbent laminate. 5. Claim 1 in which the super absorbent resin is made of one or more of starch-acrylate graft polymers, crosslinked polyacrylates, polyvinyl alcohol crosslinked polymers, starch-acrylonitrile graft polymers, etc. The water-absorbing laminate described in Section 1. 6. The water-absorbing laminate according to claim 1, wherein the adhesive resin contains thermoplastic rubber or ethylene-vinyl acetate copolymer as a main component. 7. The water-absorbing laminate according to claim 1, wherein the adhesive layer contains 2 to 100 parts of a super absorbent resin based on 100 parts of an adhesive resin. 8. The water-absorbing laminate according to claim 1 or 7, wherein the adhesive layer is porous.