JP4004654B2 - Coating material - Google Patents

Description

で示される値である。
【００４４】
尚、全ポリマー量（ｇ）が不明な場合の測定は、上記接合剤が水溶性樹脂のときには、付着ポリマーがほぼ脱落するまで４０℃の０．４重量％の水酸化ナトリウム水溶液に浸漬し（例えば２４時間浸漬）、乾燥して、浸漬前後での重量変化を全ポリマー量（ｇ）とすればよい。また、上記接合剤が疎水性樹脂のときには、その樹脂を溶解できる有機溶剤に浸漬し上記同様にその重量変化を全ポリマー量（ｇ）とすればよい。
【００４５】
水硬性組成物が注入された堀削孔中に仮埋設物を打ち込む（打設施工）場合、被覆材にも摩擦力がかかる。この打ち込みがスムーズに行われれば短時間（１分）程度で終了するため特に問題は生じないが、仮埋設物が長尺であるときは打ち込み時間が長くなることと、水硬性組成物を含んだ泥水の圧力が深部で大きくなりその摩擦力を増大させるため、シート状基材に付着している接合剤または吸水材が脱落し易くなり引抜き性を極端に低下させることがある。また、同様に再投入などにより打ち込み時間が長くなるときも脱落し易くなり引き抜き性を低下させることがある。従って、上記脱落率は５０％以下が好ましく、より好ましくは３０％以下である。脱落率が５０％を超えると上記のように仮埋設物の引き抜き性が低下する場合がある。
【００４６】
また、上記被覆材またはシート状可撓性材料に柔軟性を持たせ、取扱い性を向上させるために、上記水溶性樹脂または接合剤に多価アルコールなどの可塑剤を含ませることがさらに望ましい。
【００４７】
本発明にかかる吸水材、つまり、上記接合剤によってシート状基材に付着される吸水材は、水を吸水することができる材質からなっていればよく、特に限定されるものではないが、水膨潤性樹脂、水膨潤性樹脂を付着させた織布や不織布等の吸水シート、吸水性繊維、自重の２倍以上の水を吸水・保持することができるスポンジやフェルト等の多孔質体、等が好適である。上記例示の吸水材のうち、水膨潤性樹脂が特に好ましい。
【００４８】
上記の水膨潤性樹脂は、水を吸水することによって膨潤し、かつ、自重に対するイオン交換水の吸水倍率が３倍以上の樹脂であればよく、特に限定されるものではないが、該吸水倍率が１０倍以上の樹脂がより好ましい。該水膨潤性樹脂としては、具体的には、例えば、ポリ（メタ）アクリル酸架橋体、ポリ（メタ）アクリル酸塩架橋体、スルホン酸基を有するポリ（メタ）アクリル酸エステル架橋体、ポリオキシアルキレン基を有するポリ（メタ）アクリル酸エステル架橋体、ポリ（メタ）アクリルアミド架橋体、（メタ）アクリル酸塩と（メタ）アクリルアミドとの共重合架橋体、（メタ）アクリル酸ヒドロキシアルキルと（メタ）アクリル酸塩との共重合架橋体、ポリジオキソラン架橋体、架橋ポリエチレンオキシド、架橋ポリビニルピロリドン、スルホン化ポリスチレン架橋体、架橋ポリビニルピリジン、デンプン−ポリ（メタ）アクリロニトリルグラフト共重合体のケン化物、デンプン−ポリ（メタ）アクリル酸（塩）グラフト架橋共重合体、ポリビニルアルコールと無水マレイン酸（塩）との反応生成物、架橋ポリビニルアルコールスルホン酸塩、ポリビニルアルコール−アクリル酸グラフト共重合体、ポリイソブチレンマレイン酸（塩）架橋重合体等が挙げられる。これら水膨潤性樹脂は、必要に応じて、一種類のみを用いてもよく、また、二種類以上を併用してもよい。さらに、水膨潤性樹脂が備える各種性質（吸水倍率等）を阻害しない程度に、他の樹脂を水膨潤性樹脂と併用することもできる。
【００４９】
上記例示の水膨潤性樹脂のうち、ノニオン性基および／またはスルホン酸（塩）基を有する水膨潤性樹脂がより好ましく、アミド基またはヒドロキシアルキル基を有する水膨潤性樹脂がさらに好ましい。該水膨潤性樹脂としては、例えば、（メタ）アクリル酸塩と（メタ）アクリルアミドとの共重合架橋体、（メタ）アクリル酸ヒドロキシアルキルと（メタ）アクリル酸塩との共重合架橋体等が挙げられる。さらに、上記例示の水膨潤性樹脂のうち、ポリオキシアルキレン基を有する水膨潤性樹脂が特に好ましい。該水膨潤性樹脂としては、例えば、メトキシポリオキシアルキレン基を有する（メタ）アクリル酸エステルと（メタ）アクリル酸塩との共重合架橋体等が挙げられる。メトキシポリオキシアルキレン基を有する水膨潤性樹脂は、長期間にわたって、アルカリ性を呈する水に対する膨潤性に特に優れている。従って、該水膨潤性樹脂を用いることにより、仮埋設物を引き抜く作業を極めて容易に行うことができる。
【００５０】
尚、上記「アルカリ性を呈する水」（以下、アルカリ水と記す）とは、例えばコンクリートやモルタル等の水硬性組成物に含まれるコンクリート水等の水を示すものとする。また、アルカリ水のｐＨは、特に規定されるものではない。
【００５１】
さらに、本発明にかかる水膨潤性樹脂として、水溶性を有するエチレン性不飽和単量体と、必要に応じて架橋剤とを含む単量体成分を重合することによって得られる樹脂を用いることができる。エチレン性不飽和単量体を（共）重合してなる水膨潤性樹脂は、水に対する膨潤性により優れており、かつ、一般的に安価である。従って、該水膨潤性樹脂を用いることにより、仮埋設物を引き抜く作業を極めて容易に、かつ、より一層経済的に行うことができる。尚、上記の架橋剤は、特に限定されるものではない。また、直鎖状の高分子に、架橋剤を添加して架橋することにより、或いは、電子線を照射して架橋することにより、水膨潤性樹脂を形成することもできる。
【００５２】
上記のエチレン性不飽和単量体としては、具体的には、例えば、アクリル酸、メタクリル酸、イタコン酸、マレイン酸、フマル酸、クロトン酸、シトラコン酸、ビニルスルホン酸、（メタ）アリルスルホン酸、２−（メタ）アクリルアミド−２−メチルプロパンスルホン酸、２−（メタ）アクリロイルエタンスルホン酸、２−（メタ）アクリロイルプロパンスルホン酸、並びに、これら単量体のアルカリ金属塩やアンモニウム塩；Ｎ，Ｎ−ジメチルアミノエチル（メタ）アクリレート、並びに、その四級化物；（メタ）アクリルアミド、Ｎ，Ｎ−ジメチル（メタ）アクリルアミド、２−ヒドロキシエチル（メタ）アクリルアミド、ジアセトン（メタ）アクリルアミド、Ｎ−イソプロピル（メタ）アクリルアミド、（メタ）アクリロイルモルホリン等の（メタ）アクリルアミド類、並びに、これら単量体の誘導体；２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート；ポリエチレングリコールモノ（メタ）アクリレート、ポリプロピレングリコールモノ（メタ）アクリレート、メトキシポリエチレングリコールモノ（メタ）アクリレート、メトキシポリプロピレングリコールモノ（メタ）アクリレート等のポリアルキレングリコールモノ（メタ）アクリレート；Ｎ−ビニル−２−ピロリドン、Ｎ−ビニルスクシンイミド等のＮ−ビニル単量体；Ｎ−ビニルホルムアミド、Ｎ−ビニル−Ｎ−メチルホルムアミド、Ｎ−ビニルアセトアミド、Ｎ−ビニル−Ｎ−メチルアセトアミド等のＮ−ビニルアミド単量体；ビニルメチルエーテル；等が挙げられるが、特に限定されるものではない。これらエチレン性不飽和単量体は、一種類のみを用いてもよく、また、二種類以上を併用してもよい。
【００５３】
上記例示のエチレン性不飽和単量体のうち、ノニオン性基および／またはスルホン酸（塩）基を有するエチレン性不飽和単量体がより好ましい。該単量体としては、例えば、２−（メタ）アクリルアミド−２−メチルプロパンスルホン酸、２−（メタ）アクリロイルエタンスルホン酸、２−（メタ）アクリロイルプロパンスルホン酸、（メタ）アクリルアミド、ヒドロキシアルキル（メタ）アクリレート、メトキシポリエチレングリコールモノ（メタ）アクリレート等が挙げられる。さらに、ポリオキシアルキレン基を有するエチレン性不飽和単量体が特に好ましい。そして、メトキシポリエチレングリコールモノ（メタ）アクリレートを含む単量体成分を重合して得られる水膨潤性樹脂は、アルカリ水に対する膨潤性に特に優れている。従って、該水膨潤性樹脂を用いることにより、仮埋設物を引き抜く作業を極めて容易に行うことができる。
【００５４】
さらに、単量体成分としてエチレン性不飽和単量体を二種類以上併用する場合においては、該単量体成分に占める、ノニオン性基および／またはスルホン酸（塩）基を有するエチレン性不飽和単量体の割合を１重量％以上にすることがより好ましく、１０重量％以上にすることがさらに好ましい。上記の割合が１重量％未満である場合には、該単量体成分を重合して得られる水膨潤性樹脂を用いても、仮埋設物を引き抜く作業の作業性をさらに向上させることができなくなるおそれがある。
【００５５】
単量体成分としてエチレン性不飽和単量体を二種類以上併用する場合における、より好ましい組み合わせとしては、例えば、アクリル酸ナトリウム等の（メタ）アクリル酸アルカリ金属塩とアクリルアミドとの組み合わせ、（メタ）アクリル酸アルカリ金属塩とメトキシポリエチレングリコールモノ（メタ）アクリレートとの組み合わせ等が挙げられるが、特に限定されるものではない。
【００５６】
上記の単量体成分を重合することにより、水膨潤性樹脂が得られる。単量体成分の重合方法、つまり、水膨潤性樹脂の製造方法は、特に限定されるものではない。また、水膨潤性樹脂の平均分子量や形状、平均粒子径等は、水硬性組成物の組成やアルカリ水のｐＨ、シート状基材との組み合わせ、作業環境等に応じて設定すればよく、特に限定されるものではないが、平均粒子径が２，０００μｍ以下、より好ましくは５００μｍ以下、さらに好ましくは１５０μｍ以下である水膨潤性樹脂を用いることがより望ましい。該平均粒子径の水膨潤性樹脂を用いることにより、例えば樹脂溶液（後述する）における水膨潤性樹脂の分散性または混合性が良好となるので、その取り扱い性がより一層向上すると共に、シート状基材表面に、接合剤で付着された水膨潤性樹脂層を容易に形成することができる。さらに、単位面積当たりのシート状基材に付着される水膨潤性樹脂の量を、均一な状態で、より多くすることができる。
【００５７】
本発明にかかる被覆材においては、シート状基材に吸水材が接合剤を介して付着されているので、シート状基材と水硬性組成物の硬化物との間に、水を吸水して膨潤した吸水材の層が形成される。つまり、仮埋設物と水硬性組成物の硬化物との間に、膨潤した吸水材の層を形成することができるので、両者の接着をより一層抑制することができる。これにより、仮埋設物を水硬性組成物の硬化物から引き抜く際には、膨潤した吸水材が潤滑効果を発揮することによって、該仮埋設物が滑り易くなる。従って、仮埋設物を水硬性組成物の硬化物から引き抜く作業における労力（引張力）をより一層低減することができるので、該作業の作業性を向上させることができる。さらに、吸水材を乾燥させることにより、仮埋設物と水硬性組成物の硬化物との間に隙間を形成することができるので、上記作業の作業性をさらに一層向上させることができる。
【００５８】
そして、例えば、接合剤として水溶性樹脂を用いると共に、吸水材として水膨潤性樹脂を用いる場合における両者の割合、即ち、シート状基材に付着させるべき水溶性樹脂と水膨潤性樹脂との割合は、両者の組成や組み合わせ、作業環境等に応じて設定すればよく、特に限定されるものではないが、重量比で１／９９〜９９／１の範囲内がより好ましく、１０／９０〜９０／１０の範囲内がさらに好ましく、２５／７５〜７５／２５の範囲内が特に好ましい。
【００５９】
また、シート状基材の単位面積当たりに対する水溶性樹脂および水膨潤性樹脂の付着量は、両者の組成や組み合わせ、作業環境等に応じて設定すればよく、特に限定されるものではないが、１ｇ／ｍ² 〜１０，０００ｇ／ｍ² の範囲内がより好ましく、１０ｇ／ｍ² 〜５，０００ｇ／ｍ² の範囲内がさらに好ましく、２０ｇ／ｍ² 〜１，０００ｇ／ｍ² の範囲内が特に好ましい。尚、シート状基材１００重量部に対する水溶性樹脂および水膨潤性樹脂の割合は、１重量部〜１０，０００重量部の範囲内がより好ましく、１０重量部〜１，０００重量部の範囲内がさらに好ましく、２０重量部〜５００重量部の範囲内が特に好ましい。
【００６０】
尚、水溶性樹脂以外の接合剤を用いる場合における該接合剤と水膨潤性樹脂との割合、或いは、シート状基材の単位面積当たりに対する接合剤および水膨潤性樹脂の付着量は、両者の組成や組み合わせ、作業環境等に応じて設定すればよく、特に限定されるものではない。
【００６１】
シート状基材表面に接合剤を介して吸水材を付着させる方法は、特に限定されるものではないが、具体的には、例えば、接合剤および水膨潤性樹脂を有機溶剤や水等の分散媒に分散してなる分散液をシート状基材表面に、噴霧（スプレー）する方法；上記分散液を刷毛塗り、またはローラを用いて塗布する方法；シート状基材に上記分散液を含浸させる方法；等を採用すればよい。或いは、接合剤を含む溶液または分散液をシート状基材表面に噴霧または塗布した後、該表面に水膨潤性樹脂を均一に撒布し、さらにこの上に該溶液または分散液を噴霧または塗布する方法；等を採用することもできる。シート状基材に塗布された該分散液等は、必要に応じて乾燥させればよい。これにより、シート状基材表面（外面および／または内面）に接合剤を介して水膨潤性樹脂が付着される。つまり、水膨潤性樹脂の層が形成される。尚、シート状基材表面に、水溶性樹脂を含む樹脂層を形成する場合には、上記方法において水膨潤性樹脂を分散する工程や、水膨潤性樹脂を撒布する工程を省略すればよい。また、水膨潤性樹脂以外の吸水材を用いる場合においては、上記方法に準じた方法を採用すればよい。
【００６２】
接合剤と水膨潤性樹脂とを含む溶液または分散液の調製方法は、特に限定されるものではない。また、上記有機溶剤としては、具体的には、例えば、メチルアルコール、エチルアルコール、イソプロピルアルコール、ベンゼン、トルエン、アセトン、メチルエチルケトン、酢酸エチル、酢酸ブチル；エチレングリコール、エチレングリコールモノメチルエーテル、エチレングリコールモノメチルエーテルアセテート、ポリプロピレングリコールモノメチルエーテルアセテート等の、多価アルコールおよびその誘導体；等が挙げられるが、特に限定されるものではない。水膨潤性樹脂を含む層の膜厚は、１０μｍ程度あれば充分であるが、水膨潤性樹脂の粒子径等に応じて設定すればよく、特に限定されるものではない。
【００６３】
そして、シート状基材、即ち、被覆材においては、仮埋設物を被覆した状態において外側となる面に、上記水膨潤性樹脂等の吸水材の層、若しくは、水溶性樹脂を含む樹脂層が形成されていることがより好ましい。これにより、仮埋設物を引き抜く作業をより一層容易に行うことができると共に、例えばアルカリ水に溶解した水溶性樹脂が仮埋設物に付着することが少ないので、引き抜いた仮埋設物の表面を綺麗な状態に保つことができ、再利用（リサイクル）が容易となる。
【００６４】
さらに、接合剤として水溶性樹脂を用いる場合においては、雨等によって該水溶性樹脂が溶解することを防止するために、必要に応じて、水溶性樹脂を含む層（樹脂層）の表面に、耐水性付与剤からなる耐水性被膜を形成（トップコート）することができる。
【００６５】
上記の耐水性付与剤としては、例えば、ワックス等の従来公知の撥水剤、および、アルカリ性の液に接して溶解するアルカリ可溶性樹脂等が挙げられるが、水溶性樹脂や吸水材との組み合わせ等を考慮して選定すればよく、特に限定されるものではない。また、耐水性被膜を形成する方法は、特に限定されるものではないが、具体的には、例えば、耐水性付与剤を有機溶剤や水等の分散媒に分散してなる分散液を樹脂層表面に、噴霧（スプレー）する方法；分散液を刷毛塗り、またはローラを用いて塗布する方法；耐水性付与剤の溶融液を噴霧または塗布する方法；等を採用すればよい。樹脂層表面に塗布された該分散液等は、必要に応じて乾燥させればよい。これにより、樹脂層表面に耐水性被膜が形成される。耐水性被膜の膜厚は、５０μｍ程度あれば充分であるが、特に限定されるものではない。尚、例えば膜厚が５０μｍの耐水性被膜を形成する場合における耐水性付与剤の塗布量は、５０ｇ／ｍ² 程度とすればよいが、特に限定されるものではない。
【００６６】
水溶性樹脂を含む樹脂層表面に耐水性被膜を形成することにより、雨等がかかっても該水溶性樹脂が溶解することを防止することができる。従って、作業中の降雨等に対しても性能を損なうことがない。また、構造体を施工する際においては、作業現場で仮埋設物を被覆材で被覆することができるが、例えば、仮埋設物を被覆材で予め被覆しておき、該被覆された仮埋設物を作業現場に野積みすることもできる。従って、仮埋設物を防水シートで被覆したり、屋内の資材置場等に保管したりする必要がなくなるので、仮埋設物を簡便かつ安価に保管することができる。つまり、作業現場の状況に応じて、適宜、作業の簡便化、合理化を図ることができるので、構造体を迅速に施工することができる。
【００６７】
仮埋設物を被覆材で被覆した状態において、仮埋設物と被覆材とは、互いに接触はしているが固着はしていない。つまり、本発明にかかる被覆材は、非接着（非固着）の被覆材である。従って、仮埋設物と被覆材との間には、アルカリ水が滲入することができる空隙が形成され、それゆえ、水膨潤性樹脂の吸水膨潤性がさらに向上し、両者の接着をより一層抑制することができる。そして、膨潤した水膨潤性樹脂による潤滑効果との相乗効果によって、仮埋設物を引き抜く作業を極めて容易に行うことができる。
【００６８】
また、仮埋設物を被覆材で被覆する際には、一つの仮埋設物に対して一つの被覆材を用いることが望ましいが、必要に応じて、一つの仮埋設物に対して二つ以上の被覆材を用いることもできる。従って、仮埋設物を被覆材で被覆する方法として、例えば仮埋設物をシート状に形成された二枚の被覆材で挟み込む方法、等を採用することもできる。尚、本発明において「被覆」とは、必ずしも被覆材で仮埋設物が見えなくなるように覆い隠すことではなく、仮埋設物を水硬性組成物の硬化物から容易に引き抜くことができる程度に、つまり、両者の接着を抑制することができる程度に、仮埋設物を被覆材で覆うことを示している。
【００６９】
仮埋設物を被覆材で被覆する方法としては、具体的には、例えば、袋状若しくは筒状に形成された被覆材を仮埋設物に被せる方法、仮埋設物を袋状若しくは筒状に形成された被覆材に挿入する方法、仮埋設物をシート状に形成された被覆材で包み込む方法、等を採用することができるが、特に限定されるものではない。
【００７０】
また、仮埋設物を被覆材で被覆する際には、固定治具を用いて被覆材を仮埋設物に固定しておくことがより好ましい。これにより、仮埋設物をその形状に沿って被覆材で被覆することが可能になり、仮埋設物と水硬性組成物との接触をより効果的に抑制できると共に、仮埋設物を水硬性組成物に打ち込む際の打ち込み精度の向上を図ることができる。
【００７１】
尚、被覆材を袋状若しくは筒状に形成する方法としては、具体的には、例えば、接着剤を用いて接着する方法、ヒートシールによって融着させる方法、縫い合わせる方法、針金や紐等で縛る方法、等の種々の方法を採用することができるが、特に限定されるものではない。また、被覆材の荷姿は、特に限定されるものではないが、ロール状（図１）に巻き取られた状態、または、蛇腹状に折り畳まれた状態が、取り扱い性および作業性の観点から、より好ましい。
【００７２】
仮埋設物を被覆材で被覆する時期は、特に限定されるものではなく、作業現場に仮埋設物を運び込むまでの間の適当な時期であってもよく、作業現場で仮埋設物を保管している間の適当な時期であってもよく、仮埋設物を埋設する作業にかかるまでの間の適当な時期であってもよい。つまり、仮埋設物は、埋設される時点で、被覆材で被覆されていればよい。また、袋状若しくは筒状に形成された被覆材を用いる場合においては、該被覆材は、埋設される時点で、これら形状に形成されていればよい。
【００７３】
仮埋設物を被覆材で被覆する方法としては、より具体的には、例えば、図１（ａ）に示すように、クレーン６を用いて仮埋設物２を吊り上げると共に、該クレーン６の先端部に設けられた滑車５に通した紐３を被覆材１に取り付け、次いで、袋状若しくは筒状に形成された被覆材１を、例えば作業員４が紐３を引っ張ることにより、下方から履かせるようにして仮埋設物２に挿入した後、同図（ｂ）に示すように、作業員４が紐３をさらに引っ張ることにより、該被覆材１を引き上げて装着し固定する方法；
筒状に形成された被覆材を上方から被せるようにして仮埋設物に挿入し上端部を固定した後、クレーンを用いて仮埋設物を吊り上げ、次いで、被覆材の下端部に取り付けられた紐を例えば作業員が引っ張ることにより、該被覆材を引き下げて装着する方法；
袋状若しくは筒状に形成された被覆材を地面等に載置した後、該被覆材に仮埋設物を挿入し、次いで、被覆材を引き上げて装着し固定する方法；
仮埋設物を地面等に載置した後、該仮埋設物に袋状若しくは筒状に形成された被覆材を挿入し、次いで、仮埋設物を吊り上げると共に被覆材を引き上げて装着し固定する方法；
図２（ａ）に示すように、シート状に形成された被覆材１０の上に仮埋設物２をクレーン６等を用いて載置した後、同図（ｂ）・（ｃ）に示すように、該被覆材１０で仮埋設物２を包み込み、次いで、同図（ｄ）に示すように、被覆材１０を固定治具１１…を用いて固定する方法；
蛇腹状に折り畳んだ被覆材の間に仮埋設物を挟み込んで固定する方法；
仮埋設物の上部および下部に被覆材の両端部を固定する方法；
仮埋設物の上部および下部に被覆材の両端部を固定すると共に、該被覆材の中央部を針金（番線）や紐、ベルト、ガムテープ等を用いて固定する方法；
仮埋設物の上部に被覆材の一部分を固定し、該被覆材の残りの部分を仮埋設物に沿って垂らす方法；
等を採用することができるが、特に限定されるものではない。
【００７４】
上記例示の方法のうち、袋状若しくは筒状に形成された被覆材を、下方から履かせるようにして仮埋設物に挿入して装着する方法、並びに、仮埋設物をシート状に形成された被覆材で包み込む方法が、被覆作業の作業性に優れているので、より好ましい。尚、被覆材を仮埋設物に固定する方法は、特に限定されるものではない。また、上記固定治具１１としては、具体的には、例えば、洗濯挟み、クリップ、ゴムホースまたは断熱発泡体等のチューブ類を縦割にして形成したキャップ等のバインダー、針金（番線）、紐、ベルト、ガムテープ等が挙げられるが、特に限定されるものではない。
【００７５】
以上のように、仮埋設物を被覆材で被覆することにより、仮埋設物と水硬性組成物とが接触することを抑制し、両者を分離することができるので、仮埋設物を水硬性組成物の硬化物から引き抜く際の摩擦抵抗力を低減することができる。従って、該仮埋設物を容易に引き抜くことができるようになる。回収した仮埋設物は、そのまま再利用することができる。尚、被覆材は、仮埋設物が引き抜かれた後も構造体に残ることになるが、例えば被覆材が仮埋設物に固定されている場合には、仮埋設物と共に引き抜かれる場合もある。
【００７６】
また、上記の説明においては、仮埋設物と水硬性組成物の硬化物とで少なくとも構成される構造体に使用される仮埋設物を被覆する被覆材を例に挙げたが、本発明にかかる被覆材は、土壌に埋設される仮埋設物に対しても適用することができる。これにより、仮埋設物を土壌から引き抜く際の摩擦抵抗力を低減することができ、該仮埋設物を容易に引き抜くことができるようになる。
【００７７】
また、本発明の被覆材は、仮埋設物を被覆した状態において外側となる面に、上記樹脂層が形成されている構成を採用することもできる。上記の構成によれば、仮埋設物を引き抜く作業をより一層容易に行うことができると共に、水に溶解した水溶性樹脂が仮埋設物に付着することがないので、引き抜いた仮埋設物の表面を綺麗な状態に保つことができ、再利用（リサイクル）が容易となる。
【００７８】
本発明の被覆材は、さらに、上記接合剤が水溶性樹脂である構成を採用することもできる。上記の構成によれば、例えば、仮埋設物を水硬性組成物の硬化物から引き抜くべく、上記仮埋設物を被覆材で被覆した場合には、水硬性組成物に含まれる水に水溶性樹脂が溶解するので、吸水材が水を吸水して膨潤する際の体積膨張を阻害するおそれが無い。従って、吸水材は、その吸水特性（性能）を充分に発揮することができる。これにより、仮埋設物を水硬性組成物の硬化物から引き抜く作業における労力（引張力）をより一層低減することができるので、該作業の作業性を向上させることができる。
【００７９】
本発明の被覆材は、さらに、上記吸水材が水膨潤性樹脂である構成を採用することもできる。上記の構成によれば、膨潤した水膨潤性樹脂が潤滑効果を発揮することによって、仮埋設物がより一層滑り易くなる。従って、仮埋設物を引き抜く作業の作業性をさらに向上させることができる。
【００８０】
本発明の被覆材は、さらに、上記水膨潤性樹脂の平均粒子径が２，０００μｍ以下である構成を採用することもできる。上記の構成によれば、水溶性樹脂等の接合剤と水膨潤性樹脂との混合性がより良好となると共に、シート状基材の単位面積当たりに対する水膨潤性樹脂の付着量を、平均粒子径が２，０００μｍを越えている場合と比較して、多くすることができ、樹脂層をより一層形成し易くなる。従って、仮埋設物の引抜き性と、引き抜く作業の作業性をさらに向上させることができる。
【００８１】
本発明の被覆材は、さらに、仮埋設物を被覆した状態において外側となる面に、上記吸水材が付着している構成を採用することもできる。上記の構成によれば、仮埋設物を引き抜く作業をより一層容易に行うことができると共に、吸水材や接合剤が仮埋設物に付着することがないので、引き抜いた仮埋設物の表面を綺麗な状態に保つことができ、再利用（リサイクル）が容易となる。
【００８２】
本発明の被覆材は、さらに、上記シート状基材の引張強度が、１ｋｇｆ／２．５ｃｍ以上である構成を採用することもできる。上記の構成によれば、例えば仮埋設物を埋設するときに生じる衝撃力や引張力等の外力がかかっても破損しない強度を備えた被覆材を提供することができる。
【００８３】
本発明の被覆材は、さらに、仮埋設物を挿入可能な袋状若しくは筒状に形成されている構成を採用することもできる。上記の構成によれば、仮埋設物をより一層簡単にかつ迅速に被覆することができる。
【００８４】
【実施例】
以下、実施例および比較例により、本発明をさらに具体的に説明するが、本発明はこれらにより何ら限定されるものではない。
【００８５】
〔実施例１〕
アクリル酸ナトリウムとアクリル酸とを所定の条件下で架橋共重合させることにより水膨潤性樹脂を製造した。該水膨潤性樹脂の平均粒子径は１００μｍであった。
【００８６】
そして、Ａ４版の大きさに裁断した織布（シート状基材、ポリエステル：綿／５０：５０（重量比）、坪量２００ｇ、厚さ０．５ｍｍ）の表面（片面）に、固形分として１．２５ｇのでんぷんのり（６重量％水溶液、水溶性樹脂）を均一にスプレー撒布した。その上に、５．０ｇの該水膨潤性樹脂を均一に撒布し、さらにこの上に、固形分として１．２５ｇのでんぷんのりを均一にスプレー撒布した。次いで、水膨潤性樹脂が付着された該織布を、乾燥機を用いて１２０℃で１５分間乾燥させた。つまり、織布の片面に水膨潤性樹脂とでんぷんとを含む層を形成した。該織布には、でんぷんが４０ｇ／ｍ² 、水膨潤性樹脂が８０ｇ／ｍ² の割合で付着していた。また、該織布の引張強度は、３０ｋｇｆ／２．５ｃｍと極めて高い値を示した。
【００８７】
次に、水膨潤性樹脂とでんぷんとを含む層が形成された該織布、即ち、本発明にかかる被覆材を、上記層が外側になるようにして縫い合わせて、幅８０ｍｍ×高さ１４０ｍｍの袋体を形成した。この袋体に、仮埋設物としての、幅７０ｍｍ×高さ１５０ｍｍ×厚さ０．８ｍｍの鉄板（日本テストパネル大阪製）を挿入した。
【００８８】
一方、水とセメントと粘土とベントナイトとを、重量比２５：１２：１６：０．６で混合することにより、ソイルセメントミルク（水硬性組成物）を調製した。そして、上記の袋体を、容器に入れたソイルセメントミルクに埋め込んだ。つまり、被覆材で被覆された鉄板をソイルセメントミルクに打ち込んだ後、該ソイルセメントミルクを硬化させた。
【００８９】
鉄板を打ち込んでから３日間経過後、該鉄板をソイルセメントミルクの硬化物から、引張試験機を用いて引き抜いた。該引き抜き作業に要した引抜き荷重は０．９ｋｇｆであり、鉄板はソイルセメントミルクの硬化物から極めて容易に引き抜くことができた。
【００９０】
〔比較例１〕
実施例１の操作と同様の操作を行って被覆材を作成した。次いで、この被覆材を、幅７０ｍｍ×高さ１５０ｍｍ×厚さ０．８ｍｍの鉄板の両面に、接着剤を用いて貼着した。つまり、被覆材を鉄板の両面に直接的に固着した。
【００９１】
次に、実施例１の操作と同様の操作を行うことにより、上記の鉄板をソイルセメントミルクに埋め込んだ。つまり、被覆材が固着された比較用の鉄板をソイルセメントミルクに打ち込んだ後、該鉄板をソイルセメントミルクの硬化物から引き抜いた。該引き抜き作業に要した引抜き荷重は５．０ｋｇｆであり、鉄板はソイルセメントミルクの硬化物から容易に引き抜くことができなかった。
【００９２】
〔実施例２〕
水溶性樹脂の代わりに、合成ゴム系接合剤（住友スリーエム株式会社製；商品名「３Ｍ スプレーのり９９」）を用いて、被覆材を製造した。該接合剤の成分は、スチレンブタジエンゴム等の合成ゴム１０重量％、ｎ−ペンタンやアセトン、トルエン等の有機溶剤４０重量％、ＬＰＧやジメチルエーテル等のガス（スプレー用）５０重量％である。
【００９３】
先ず、アクリル酸ナトリウムとアクリルアミドとを所定の条件下で架橋共重合させることにより水膨潤性樹脂を製造した。該水膨潤性樹脂の平均粒子径は２００μｍであった。
【００９４】
そして、Ａ４版の大きさに裁断した不織布の表面（片面）に、合成ゴム（固形分）の付着量が０．５ｇとなるように該接合剤を均一にスプレー撒布した。その上に、２．５ｇの該水膨潤性樹脂を均一に撒布し、さらにこの上に、合成ゴムの付着量が１．５ｇとなるように該接合剤を均一にスプレー撒布した。そして、該不織布の裏面にも、上記操作と同様の操作を行って、水膨潤性樹脂を合成ゴムにて付着させた。次いで、水膨潤性樹脂が付着された該不織布を、乾燥機を用いて１００℃で５分間乾燥させた。該不織布には、合成ゴムが６４ｇ／ｍ² 、水膨潤性樹脂が８０ｇ／ｍ² の割合で付着していた。
【００９５】
次に、実施例１の操作と同様の操作を行うことにより、袋状の被覆材で被覆された鉄板をソイルセメントミルクに打ち込んだ後、該鉄板をソイルセメントミルクの硬化物から引き抜いた。該引抜き作業に要した引抜き荷重は３．０ｋｇｆであり、鉄板はソイルセメントミルクの硬化物から容易に引き抜くことができた。
【００９６】
〔比較例２〕
実施例２で用いた合成ゴム系接合剤を、幅７０ｍｍ×高さ１５０ｍｍ×厚さ０．８ｍｍの鉄板の片面に、その付着量が０．５ｇとなるように均一にスプレー撒布した。その上に、実施例２で製造した水膨潤性樹脂２．５ｇを均一に撒布し、さらにこの上に、合成ゴムの付着量が１．５ｇとなるように該接合剤を均一にスプレー撒布した。そして、該鉄板の裏面にも、上記操作と同様の操作を行って、水膨潤性樹脂を合成ゴムにて付着させた。次いで、該鉄板を乾燥機を用いて１００℃で５分間乾燥させた。鉄板には、合成ゴムが６４ｇ／ｍ² 、水膨潤性樹脂が８０ｇ／ｍ² の割合で付着していた。
【００９７】
次に、実施例１の操作と同様の操作を行うことにより、本発明にかかる袋状の被覆材で被覆されていない鉄板をソイルセメントミルクに打ち込んだ後、該鉄板をソイルセメントミルクの硬化物から引き抜いた。該引き抜き作業に要した引抜き荷重は７．０ｋｇｆであり、上記実施例２の結果と比較して引抜き荷重が大きく、鉄板はソイルセメントミルクの硬化物から容易に引き抜くことができなかった。
【００９８】
〔実施例３〕
Ａ４版の大きさに裁断した織布（シート状基材、ポリエステル：綿／６５：３５（重量比）、坪量１５０ｇ、厚さ０．４ｍｍ）の表面（片面）に、固形分として１．２５ｇの８８％けん化ポリビニルアルコール（商品名 クラレポバールＰＶＡ−２１７、水溶性樹脂）が付着するように、該ポリビニルアルコールの水溶液を均一にスプレー撒布した。
【００９９】
その上に、アクリル酸ナトリウム塩とアクリル酸とを所定の条件下で架橋共重合させることにより製造した水膨潤性樹脂（平均粒子径１００μｍ）５．０ｇを均一に撒布し、さらにこの上に、固形分として１．２５ｇの８８％けん化ポリビニルアルコールが付着するように、該ポリビニルアルコールの水溶液を均一にスプレー撒布した。次いで、水膨潤性樹脂が付着された該織布を、乾燥機を用いて１２０℃で４０分間乾燥させた。つまり、織布の片面に水膨潤性樹脂とポリビニルアルコールとを含む層を形成した。該織布には、８８％けん化ポリビニルアルコールが４０ｇ／ｍ² 、水膨潤性樹脂が８０ｇ／ｍ² の割合で付着していた。また、該織布の引張強度は、５２ｋｇｆ／２．５ｃｍと極めて高い値を示した。
【０１００】
次に、水膨潤性樹脂と８８％けん化ポリビニルアルコールとを含む層が形成された該織布、即ち、本発明にかかる被覆材を、上記層が外側になるようにして縫い合わせて、幅８０ｍｍ×高さ１４０ｍｍの袋体を形成した。この袋体に、仮埋設物としての、幅７０ｍｍ×高さ１５０ｍｍ×厚さ０．８ｍｍの鉄板（日本テストパネル大阪製）を挿入した。
【０１０１】
次に、実施例１の操作と同様の操作を行うことにより、袋状の被覆材で被覆された鉄板をソイルセメントミルクに打ち込んだ後、該鉄板をソイルセメントミルクの硬化物から引き抜いた。該引抜き作業に要した引抜き荷重は０．７ｋｇｆであり、鉄板はソイルセメントミルクの硬化物から容易に引き抜くことができた。
【０１０２】
〔実施例４〕
本発明にかかる被覆材のポリマーの脱落率試験、即ち、織布に付着しているポリマーの脱落率試験を行った。先ず、実施例３に記載の被覆材の材料および作成方法に基づき、下記に示す三種類の試料を、脱落率試験用の試料として用意した。尚、本実施例におけるポリマーとは、水溶性樹脂（接合剤）および水膨潤性樹脂（吸水材）を合わせたものを示す。
【０１０３】
ア．８８％けん化ポリビニルアルコールの付着量を８０ｇ／ｍ² （片面）とした以外は、実施例３と同様の操作を行って、試料▲１▼を作製した。
【０１０４】
イ．８８％けん化ポリビニルアルコールの代わりに完全けん化ポリビニルアルコールを用い、その付着量を８０ｇ／ｍ² （片面）とした以外は、実施例３と同様の操作を行って、試料▲２▼を作製した。
【０１０５】
ウ．８８％けん化ポリビニルアルコールの代わりにでんぷんのりを用い、その付着量を８０ｇ／ｍ² （片面）とした以外は、実施例３と同様の操作を行って、試料▲３▼を作製した。
【０１０６】
そして、イオン交換水が注入された１００ｍｌの容器内に、縦５ｃｍ×横５ｃｍに裁断した上記三種類の試料▲１▼〜▲３▼を入れて５分間浸漬した後、これら試料▲１▼〜▲３▼をイオン交換水より引き上げ、余分な水を除去した後に乾燥した。
【０１０７】
次に、イオン交換水に浸漬する前と浸漬した後（乾燥させた後）との試料の重量変化から、織布から脱落したポリマー量を測定し、脱落したポリマー量（ｇ）をイオン交換水に浸漬する前に織布に付着していた全ポリマー量（ｇ）で除して、脱落率（％）を算出した。つまり、

で示される脱落率（％）を算出した。
【０１０８】
その結果、試料▲１▼〜▲３▼の脱落率は、この順に２８．５％、１１．６％、７０．９％であった。従って、水溶性樹脂（接合剤）の中でも、ポリビニルアルコールが、施工前或いは施工中における、水膨潤性樹脂（吸水材）の織布（シート状基材）からの脱落を防止する性能に、より一層優れていることが判った。
【０１０９】
【発明の効果】
本発明の請求項１記載の被覆材は、以上のように、仮埋設物を非接着状態で被覆する被覆材であって、シート状基材に、水溶性樹脂を含む樹脂層が形成されている構成である。
【０１１０】
上記の構成によれば、水溶性樹脂が溶解することにより、シート状基材と水硬性組成物の硬化物との間に易剥離層を形成することができるので、仮埋設物を水硬性組成物の硬化物から引き抜く作業における労力（引張力）を低減することができ、該作業の作業性を向上させることができる。それゆえ、上記の構成によれば、仮埋設物を引き抜く作業を改善することができる被覆材を提供することができるという効果を奏する。
【０１１１】
本発明の請求項２記載の被覆材は、以上のように、仮埋設物を非接着状態で被覆する被覆材であって、シート状基材と、吸水材と、該吸水材をシート状基材に付着させる接合剤とを含む構成である。
【０１１２】
上記の構成によれば、仮埋設物と例えば水硬性組成物の硬化物との間に、膨潤した吸水材の層を形成することができるので、両者の接着をより一層抑制することができる。これにより、仮埋設物を水硬性組成物の硬化物から引き抜く際には、膨潤した吸水材が潤滑効果を発揮することによって、該仮埋設物が滑り易くなる。従って、仮埋設物を水硬性組成物の硬化物から引き抜く作業における労力（引張力）をより一層低減することができるので、該作業の作業性を向上させることができるという効果を奏する。さらに、吸水材を乾燥させることにより、仮埋設物と水硬性組成物の硬化物との間に隙間を形成することができるので、上記作業の作業性をさらに一層向上させることができるという効果も併せて奏する。
【０１１３】
本発明の請求項３記載の被覆材は、以上のように、上記水溶性樹脂または接合剤が、上記シート状基材からの脱落率が５０％以下である水溶性樹脂である構成である。
【０１１４】
上記の構成によれば、施工前或いは施工中にシート状基材から水溶性樹脂（または接合剤）が脱落することをより一層抑制することができるので、シート状基材と水硬性組成物の硬化物との間に充分な易剥離層を形成することができる。従って、仮埋設物を水硬性組成物の硬化物から引き抜く作業における労力（引張力）を低減することができ、該作業の作業性を向上させることができるという効果を奏する。
【０１１５】
本発明の請求項４記載のシート状可撓性材料は、以上のように、シート状基材に、少なくとも水溶性樹脂と吸水材とを含む、該シート状基材からの脱落率が５０％以下である樹脂層が形成されている構成である。
【０１１６】
上記の構成によれば、例えば、各種物品を被覆するのに好適なシート状可撓性材料を提供することができるという効果を奏する。
【図面の簡単な説明】
【図１】（ａ）、（ｂ）共に、本発明の実施の一形態にかかる被覆材を用いて仮埋設物を被覆する手順を示す概略の斜視図である。
【図２】（ａ）〜（ｄ）共に、本発明の実施の他の形態にかかる被覆材を用いて仮埋設物を被覆する手順を示す概略の斜視図である。
【符号の説明】
１ 被覆材
２ 仮埋設物
１０ 被覆材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a covering material for covering a temporary embedded object. More specifically, the present invention is, for example, a structure composed of at least a temporary embedded object and a cured product of a hydraulic composition so that the temporary embedded object embedded in the soil can be pulled out more easily. In order to suppress the adhesion between the two so that the temporary embedded object can be more easily pulled out from the cured product of the hydraulic composition, the present invention relates to a covering material that covers the temporary embedded object.
[0002]
[Prior art]
In general, when constructing a ground foundation structure as a structure such as a retaining wall in foundation work in the construction field and civil engineering field, for example, an H-shaped steel is loosely inserted into the excavation hole, and then around the H-shaped steel. Injecting and hardening a hydraulic composition such as cement milk or ready-mixed concrete, or embedding (injecting), for example, H-shaped steel into the hydraulic composition injected into the excavation hole as the core. Curing the composition is performed. After the hardening of the hydraulic composition is completed, it is desired that the H-shaped steel is pulled out of the hardened material and removed so as not to become an obstacle when the underground is developed again later.
[0003]
However, the H-shaped steel and the cured product of the hydraulic composition are firmly bonded, and in order to remove the H-shaped steel after completion of the construction, the work of pulling out the H-shaped steel from the cured product has an adhesive strength (adhesive strength). Because considerable labor (tensile force) is required to overcome this, equipment, costs, days, etc. are required.
[0004]
Therefore, in order to easily perform the above-described drawing operation, conventionally, i) a method of previously applying a lubricating oil such as wax or grease to the surface of the H-shaped steel, or using a water absorbent resin on the surface of the H-shaped steel. Various methods have been proposed, such as a method of adhering to the surface, ii) a method of attaching a lubricant to the surface of the H-shaped steel, and iii) a method of coating the H-shaped steel with a coating material.
[0005]
As a method of i), for example, JP-A-64-58715 discloses a core material comprising a water-absorbing resin and a spreading agent such as a polyester resin, a vinyl resin, an acrylic resin, or a urethane resin. It has been proposed to use a surface treatment agent for drawing. Further, for example, in Japanese Patent Application Laid-Open No. 63-165615, a water swellable film composed of a water-absorbing resin and a volatile film-forming resin such as natural rubber, synthetic rubber or plastic is used. A method for reducing the frictional resistance has been proposed.
[0006]
Moreover, as a method of the above ii), for example, JP-A-6-185054 proposes sticking a sheet-like lubricant made of superabsorbent fibers to the surface of a steel material. Further, for example, Japanese Patent Application Laid-Open No. 62-174418 proposes a method for reducing the frictional resistance force when a steel material is drawn using a lubricating tape made of a water absorbent resin and a binder.
[0007]
Moreover, as a method of the above iii), for example, JP-A-7-247549 discloses a bag-like lubricant comprising a polymer sheet in which a water-absorbing resin is directly fixed to a base material such as a woven fabric or a non-woven fabric. A method for reducing the frictional resistance when the temporary embedded object is pulled out by covering the temporary embedded object is proposed.
[0008]
[Problems to be solved by the invention]
However, the spreading agent contained in the surface treatment agent described in JP-A-64-58715, and the volatile film-forming resin contained in the water-swellable film described in JP-A-63-165615, It is poor in solubility or swellability in alkaline water (hereinafter referred to as cement water) contained in the hydraulic composition. For this reason, the spreading agent and the volatile film-forming resin inhibit volume expansion when the water-absorbing resin swells by absorbing water. In the conventional surface treatment agent and the water-swellable film, the spreading agent and the volatile film-forming resin cover the surface of the water-absorbent resin in this way, and hinder the volume expansion of the water-absorbent resin. Resin cannot fully exhibit its water absorption characteristics (performance). Furthermore, the water-absorbent resin contained in the conventional surface treatment agent and the water-swellable film is poor in swelling property with respect to cement water. In addition, the coating film formed by applying a surface treatment agent to a core material (temporary embedment) such as H-shaped steel and the water-swellable film are inferior in flexibility and toughness. It is easy to peel off or stick to the core due to changes. In addition, when a surface treatment agent is applied at a work site, there is a disadvantage that it is necessary to secure labor, time, place, and the like for heating, melting, and applying the surface treatment agent.
[0009]
In addition, the lubricant described in JP-A-6-185054 and the lubricating tape described in JP-A-62-174418 have low water-absorbing swelling properties of superabsorbent fibers and water-absorbent resins with respect to cement water, Therefore, the improvement property of the extraction | drawer operation | work of a temporary buried thing is inadequate. Also, the surface of temporary buried objects (steel materials) usually has rust, dirt, etc. attached, making it difficult for the lubricant tape to stick to it, and contact with cement water during construction, and sudden wetting / raining. The water-absorbing resin easily falls off. For this reason, the lubricating tape cannot exhibit an effect. Moreover, when temporary burying objects are piled up, there are many restrictions on construction, such as when the temporary burying objects get wet due to rain or the like, the lubricating tape cannot be attached. On the other hand, the surface of the temporary buried object (steel material) to which the lubricant is attached is usually attached with rust, dirt, etc., so that the lubricant is difficult to attach, and therefore the same as above. The problem will be invited.
[0010]
Furthermore, the conventional surface treatment agent, water-swellable film, lubricant, and lubricant tape are directly fixed to a core material such as H-shaped steel. Therefore, these surface treatment agents can only come into contact with cement water only on one side (surface side), so that the water-absorbent resin and super-absorbent fiber exhibit their water absorption characteristics (performance) sufficiently. Therefore, it becomes difficult to pull out the core material from the cured product of the hydraulic composition.
[0011]
Therefore, the conventional surface treatment agent, water-swellable film, lubricant, and lubricant tape have problems in that satisfactory performance cannot be obtained and the effect of facilitating the work of pulling out the core material such as H-shaped steel is insufficient. is doing.
[0012]
Moreover, the bag-shaped lubricant described in JP-A-7-247549 has the water-absorbing resin directly and firmly fixed to the base material. As the lubricant, a thin base material that is flexible and has low fiber regulation is used. This is because if a base material with a high thickness and a high strength is used, the productivity of the product (lubricant) will be extremely reduced, and if a base material with strong fiber regulations is used, the texture will be hard, This is because the quality of the product (lubricant) deteriorates. Therefore, the conventional bag-like lubricant using a low-strength base material is damaged by an external force applied when the core material is coated or when the core material is embedded (dried) into the injected hydraulic composition. There is a risk. For this reason, the core material may not be sufficiently prevented from adhering to the cured product of the hydraulic composition.
[0013]
Therefore, a coating material that can facilitate the work of pulling out the core material such as H-shaped steel, that is, without causing the above-mentioned various problems in constructing the core material, the core material is a hydraulic composition. There is a need for a coating material that can be more easily and reliably extracted from the cured product. In addition, at present, the drawability and workability are insufficient, and there are problems such as the necessity of suddenly bringing in a larger drawing device than expected at the time of drawing work, but because there is no alternative technology, Only a method of directly applying lubricating oil to the surface of a core material such as H-shaped steel and a method of covering the core material with a polyvinyl chloride sheet or the like having lubricity have been implemented.
[0014]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a covering material that can improve the work of pulling out a core material (temporary buried object) such as H-shaped steel. is there.
[0015]
[Means for Solving the Problems]
The inventors of the present application have made extensive studies on coating materials in order to solve the above-described conventional problems. As a result, a coating material in which a resin layer containing a water-soluble resin is formed on a sheet-like base material, or a sheet-like base material, a water-absorbing material such as a water-swellable resin, and the water-absorbing material is converted into a sheet-like base material. By covering the temporary embedded object with a covering material containing a bonding agent that adheres to the adhesive, for example, adhesion between the temporary embedded object and the cured product of the hydraulic composition can be suppressed, and the temporary embedded object is It has been found that the workability of the work of pulling out the hardened composition can be improved, and the present invention has been completed.
[0016]
That is, the covering material of the invention according to claim 1 is a covering material that covers a temporary embedded object in a non-adhered state in order to solve the above-described problem, and is a resin containing a water-soluble resin in a sheet-like base material It is characterized in that a layer is formed.
[0017]
According to said structure, for example, when the said temporary embedment is covered with a covering material in order to pull out the temporary embedment from the cured product of the hydraulic composition, the water-soluble resin is contained in the water contained in the hydraulic composition. By dissolving, an easy peeling layer can be formed between the sheet-like base material and the cured product of the hydraulic composition, so the labor in the work of pulling out the temporary embedded object from the cured product of the hydraulic composition ( Tensile force) can be reduced, and the workability of the work can be improved. In addition, since the covering material is not directly attached to the temporary buried object, the covering material can be brought into contact with water contained in the hydraulic composition on both surfaces (the outer surface and the inner surface). Therefore, it becomes easier to form an easily peelable layer between the sheet-like substrate and the cured product of the hydraulic composition. Further, since the resin layer is formed on a sheet-like base material such as a woven cloth that is flexible and can be penetrated by the resin solution, the resin layer is firmly adhered (attached) to the sheet-like base material, and therefore When the resin layer further contains a water-absorbing material, it is possible to prevent the water-absorbing material from being detached before or during construction. Therefore, according to said structure, the coating | covering material which can improve the operation | work which draws out a temporary burying thing can be provided.
[0018]
A covering material according to a second aspect of the present invention is a covering material that covers a temporary embedded object in a non-adhered state in order to solve the above-described problem, and is a sheet-like base material, a water absorbing material, and the water absorbing material. And a bonding agent for adhering the material to the sheet-like substrate.
[0019]
According to the above configuration, for example, when the temporary embedded object is covered with a covering material in order to extract the temporary embedded object from the cured product of the hydraulic composition, between the temporary embedded object and the hydraulic composition. A layer of the water-absorbing material swollen by absorbing water is formed. That is, since the layer of the swollen water-absorbing material can be formed between the temporarily embedded object and the cured product of the hydraulic composition, adhesion between the two can be further suppressed. Thereby, when pulling out a temporary burying thing from the hardened | cured material of a hydraulic composition, this temporary burying thing becomes easy to slip because the swollen water absorption material exhibits a lubricating effect. Therefore, since the labor (tensile force) in the operation of pulling out the temporary embedded object from the cured product of the hydraulic composition can be further reduced, the workability of the operation can be improved. Furthermore, by drying the water absorbing material, a gap can be formed between the temporary embedded object and the cured product of the hydraulic composition, so that the workability of the above work can be further improved.
[0020]
In order to solve the above problems, the covering material of the invention described in claim 3 is the covering material according to claim 1 or 2, wherein the water-soluble resin or the bonding agent is detached from the sheet-like substrate. It is characterized by being a water-soluble resin having a rate of 50% or less.
[0021]
According to said structure, since it can suppress further that water-soluble resin (or bonding agent) falls from a sheet-like base material before construction or during construction, a sheet-like base material and a hydraulic composition of A sufficient easy peeling layer can be formed between the cured product. Therefore, the labor (tensile force) in the operation | work which draws a temporary embedment from the hardened | cured material of a hydraulic composition can be reduced, and the workability | operativity of this operation | work can be improved.
[0022]
According to a fourth aspect of the present invention, there is provided a sheet-like flexible material comprising: a sheet-like base material comprising at least a water-soluble resin and a water-absorbing material; A resin layer having a drop-off rate of 50% or less is formed.
[0023]
According to said structure, the sheet-like flexible material suitable for coat | covering various articles | goods can be provided, for example.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The temporary buried object to be covered with the covering material according to the present invention may be any buried object that is buried on the assumption that it is pulled out after use or when it becomes unnecessary, or a buried object that is desirably pulled out. Although it is not limited, in the following description, the temporary embedded object used in a structure composed of at least a temporary embedded object and a cured product of the hydraulic composition will be taken as an example. That is, in the following description, a covering material that covers a temporary embedded object used for the structure is taken as an example.
[0025]
Examples of the structure include ground foundation structures such as retaining retaining walls and foundations in foundation work in the construction field and civil engineering field. Examples of the hydraulic composition constituting the structure include, but are not limited to, various concretes such as soil cement, various mortars, etc., and generally in the foundation work in the construction field and civil engineering field. What is necessary is just the hydraulic composition used when constructing ground foundation structures, such as a retaining wall and a foundation. The hydraulic composition becomes a cured product by curing. The type and combination of cement, admixture, admixture, aggregate, reinforcing material and the like contained in the hydraulic composition, that is, the composition of the hydraulic composition is not particularly limited.
[0026]
Specifically, as the temporary buried object constituting the structure, for example, steel sheet piles that are H-shaped steel, I-shaped steel, steel pillars, concrete piles, poles, cylindrical piles (hollow piles), and long plate-like piles (Sheet pile), corrugated sheet, etc. are mentioned, but it is not particularly limited. Temporary buried objects are generally used when constructing ground foundation structures such as retaining walls and foundations in foundation work in the construction and civil engineering fields, and must be pulled out from the cured product of the hydraulic composition after use. There may be a buried object (core material) or a buried object that is desirably pulled out. Moreover, the shape, length, material, etc. of a temporary burying thing are not specifically limited.
[0027]
The sheet-like base material constituting the covering material (sheet-like flexible material) according to the present invention has various external forces applied when constructing the ground foundation structure, for example, the weight of the temporary buried object or the hydraulic composition. Tensile force and shearing force generated by the above; impact force and tensile force generated when embedding a temporary embedment, frictional force with a hydraulic composition; However, it is not particularly limited as long as it is made of a material having strength that does not break.
[0028]
Specific examples of the material for the sheet-like base material include, for example, a split fiber nonwoven fabric (for example, “Warif“ trade name ”), carpet, felt, asbestos fabric, asbestos felt, glass fiber nonwoven fabric, glass fiber reinforced plastic, stitch Nonwoven fabrics such as bonded nonwoven fabrics and needle punched nonwoven fabrics; flat yarn fiber fabrics, cotton fabrics, hemp fabrics, striped fabrics, strips, synthetic resin fabrics made of polypropylene, etc .; polyester fabrics and cotton fibers blended Foam formed by forming closed cells and / or open cells inside a material made of polystyrene, polyethylene, polypropylene, vinyl chloride resin, urethane resin, phenol resin, rubber foam, etc. Body: Urethane rubber, silicone rubber, fluorine rubber, ether rubber, acrylic rubber, rubber Rubber sheet, neoprene (chloroprene rubber), butadiene-acrylonitrile copolymer, elastomer sheet made of natural rubber, etc., plastic sheet made of polyethylene, polypropylene, polyethylene terephthalate, polyamide (nylon), vinyl chloride resin, acrylic resin, leather sheet, Wood sheet, water-resistant paper sheet, natural product sheet such as cardboard sheet, metal sheet made of aluminum, iron, copper, silver, etc., alloy sheet made of stainless steel, stainless steel fiber sheet, ceramic fiber sheet, aluminum, etc. Sheets such as metal foil made of iron, copper, silver, etc., alloy metal foil made of stainless steel, etc .; polyethylene, polypropylene, polyethylene terephthalate, polyamide (nylon), vinyl chloride resin, acrylic resin, etc. Ranaru net or mesh, aluminum, iron, copper, silver or the like net or mesh made of, net or mesh made of an alloy such as stainless steel, net mesh such like; and the like. Only one kind of these materials may be used, or two or more kinds may be used in combination (composite).
[0029]
Among the above-exemplified materials, it is superior in water permeability and processability, and is inexpensive, so it is a split fiber nonwoven fabric, needle punched nonwoven fabric, flat yarn fiber fabric, cotton fabric, hemp fabric, strip fabric, synthetic resin fabric, and A blended fabric is particularly preferred.
[0030]
In addition, among the above-exemplified materials, for a material that does not have water permeability, for example, sheets and the like, for example, cuts and holes may be formed. In this case, the shape, size, number, and formation position of the cuts and holes are not particularly limited, and may be within a range in which the strength at which the sheet-like substrate is not damaged even when the external force is applied can be maintained. And can be set as appropriate.
[0031]
The thickness of the sheet-like substrate may be set according to the material and is not particularly limited, but is preferably in the range of 0.01 mm to 10 mm, and more preferably in the range of 0.05 mm to 8 mm. A range of 0.2 mm to 5 mm is particularly preferable. If the thickness of the sheet-like base material is thicker than 10 mm, the flexibility of the covering material may be reduced. Moreover, since a coating | covering material becomes bulky, there exists a possibility that the handleability and storage property may fall. If the thickness of the sheet-like base material is less than 0.01 mm, the strength that can withstand external force may not be maintained.
[0032]
The basis weight of the sheet-like substrate may be set according to the material and thickness, and is not particularly limited, but is 10 g / m. ² -10,000g / m ² Is more preferably in the range of 20 g / m ² ~ 1,000g / m ² It is further preferable to be within the range.
[0033]
The tensile strength of the sheet-like substrate is not particularly limited, but is more preferably 1 kgf / 2.5 cm or more, further preferably 10 kgf / 2.5 cm or more, and 30 kgf / 2.5 cm or more. It is particularly preferred that If the tensile strength is 1 kgf / 2.5 cm or more, the sheet-like substrate can maintain a strength that does not break even when the external force is applied. When the tensile strength of the sheet-like base material is less than 1 kgf / 2.5 cm, it tends to be torn or torn when an external force is applied.
[0034]
The above-mentioned tensile strength is measured using JIS L 1096 (sheet-like base material) using a test piece (sheet-like base material) that was cut into a size of 2.5 cm in width and 20 cm in length and then sufficiently immersed in ion-exchanged water for 30 minutes. Using a low-speed extension tensile tester based on the tensile test method (tensile strength) of General Textile Test Method), measurement was performed under the conditions of a tensile speed of 20 mm / min and a gripping interval of 10 cm. It can be determined that the larger the measured value (unit: kgf / 2.5 cm) obtained by the tester, the greater the tensile strength of the sheet-like substrate.
[0035]
The sheet-like base material, that is, the covering material only needs to be formed in a shape and size capable of covering the temporary embedded object, but the temporary embedded object can be inserted as described in detail later. More preferably, it is formed in a bag shape or a cylindrical shape. By forming a sheet-like base material (that is, a covering material) into a bag shape or a cylindrical shape, it is possible to more easily and quickly cover a large and heavy temporary buried object. The property can be further improved.
[0036]
The bonding agent contained in the coating material according to the present invention is not particularly limited as long as it is a substance that can attach the water absorbing material to the sheet-like substrate. Examples of the bonding agent include water-soluble resins, water-dispersed resins (emulsions), solvent-based resins, hot melt resins, and pressure-sensitive adhesives.
[0037]
Specific examples of the water-soluble resin include starch paste, soluble starch, modified starch, dextrin, methylcellulose, partial methylcellulose, carboxymethylcellulose; polyvinyl alcohol, polyvinyl butyral, polyvinyl formal, polyvinyl acetate, and the like. Examples thereof include, but are not limited to, polyvinyl alcohol derivatives; polyacrylic acid; and the like. These water-soluble resins may be used alone or in combination of two or more. When the above water-soluble resin is used in combination with a water-absorbing material such as a water-swellable resin, the water-soluble resin functions as a binder (bonding agent) for adhering the water-absorbing material to the sheet-like substrate, but not in combination with the water-absorbing material. In, a resin layer is formed on the surface of a sheet-like substrate.
[0038]
Specific examples of the water-dispersed resin include natural rubber, synthetic rubber, vinyl acetate resin, acrylic acid ester copolymer, polymethyl methacrylate, and styrene-butyl acrylate copolymer. There is no particular limitation. The water-dispersed resin can be obtained by dispersing or suspending these rubbers and synthetic resins in water. These water-dispersed resins may be used alone or in combination of two or more.
[0039]
Specific examples of the solvent-based resin include, but are not particularly limited to, polyester resins, vinyl resins, acrylic resins, urethane resins, and the like. The solvent-based resin is obtained by dissolving or dispersing these synthetic resins in a solvent. Only one kind of these solvent-based resins may be used, or two or more kinds thereof may be used in combination. Specific examples of the solvent include, but are not limited to, methyl alcohol, ethyl alcohol, ethyl acetate, methyl ethyl ketone, toluene, hexane, and the like. These solvents may be used alone or in combination of two or more.
[0040]
Specific examples of the hot melt resin include ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), polyethylene, polyamide, polyester, and atactic polypropylene. However, it is not particularly limited. These hot melt resins may be used alone or in combination of two or more.
[0041]
Specific examples of the pressure-sensitive adhesive include, but are not particularly limited to, an acrylic pressure-sensitive adhesive, a polyisobutylene pressure-sensitive adhesive, an SBR pressure-sensitive adhesive, and a butyl rubber pressure-sensitive adhesive. These pressure-sensitive adhesives may be used alone or in combination of two or more.
[0042]
Of the above-described bonding agents, the water-soluble resin dissolves in water, and therefore, the water-absorbing material is more preferable because there is no risk of hindering volume expansion when the water-absorbing material absorbs water and swells. Among the above water-soluble resins, polyvinyl alcohol is more excellent in the performance of preventing dropping from a sheet-like substrate such as a water absorbing material (described later). More specifically, the following dropping rate is 50%. Since it can suppress to the following, it is especially preferable.
[0043]
In the present invention, the drop-off rate from the sheet-like substrate is a value calculated by the following method. That is, the drop-off rate (%) is determined from the change in weight of the coating material according to the present invention before being immersed in ion-exchanged water and after being immersed for 5 minutes (after being dried). Measure the amount of polymer dropped (combination of bonding agent and water-absorbing material), and the total amount of polymer (g) attached to the sheet-like substrate before immersing the amount of dropped polymer (g) in ion-exchanged water It is a value calculated by dividing by. That means

This is the value indicated by.
[0044]
In the case where the total polymer amount (g) is unknown, when the bonding agent is a water-soluble resin, it is immersed in a 0.4 wt% aqueous sodium hydroxide solution at 40 ° C. until the adhered polymer is almost removed ( For example, immersion for 24 hours) and drying, and the weight change before and after immersion may be the total polymer amount (g). When the bonding agent is a hydrophobic resin, the resin may be immersed in an organic solvent capable of dissolving the resin, and the weight change may be set to the total polymer amount (g) as described above.
[0045]
When a temporary burying object is driven into the excavation hole into which the hydraulic composition has been injected (placement construction), a frictional force is also applied to the coating material. If this implantation is carried out smoothly, it will be completed in a short time (about 1 minute), so there is no particular problem. However, when the temporary embedded object is long, the implantation time becomes long and the hydraulic composition is contained. Since the pressure of the muddy water increases in the deep part and increases its frictional force, the bonding agent or water absorbing material adhering to the sheet-like base material tends to fall off and the pullability may be extremely reduced. Similarly, when the driving time becomes longer due to re-injection or the like, it may be easily dropped and the pullability may be lowered. Therefore, the drop-off rate is preferably 50% or less, more preferably 30% or less. When the drop-off rate exceeds 50%, the pullability of the temporary buried object may be lowered as described above.
[0046]
Further, in order to give the covering material or the sheet-like flexible material softness and improve the handleability, it is further desirable to include a plasticizer such as a polyhydric alcohol in the water-soluble resin or the bonding agent.
[0047]
The water-absorbing material according to the present invention, that is, the water-absorbing material attached to the sheet-like base material by the bonding agent is not particularly limited as long as it is made of a material that can absorb water. Swellable resin, water-absorbing sheet such as woven or non-woven fabric to which water-swellable resin is attached, water-absorbing fiber, porous material such as sponge or felt that can absorb and retain water more than twice its own weight, etc. Is preferred. Of the water-absorbing materials exemplified above, a water-swellable resin is particularly preferable.
[0048]
The water-swellable resin is not particularly limited as long as it is a resin that swells by absorbing water and has a water absorption ratio of 3 times or more with respect to its own weight. Is more preferably 10 times or more. Specific examples of the water-swellable resin include, for example, a crosslinked poly (meth) acrylic acid, a crosslinked poly (meth) acrylate, a crosslinked poly (meth) acrylate ester having a sulfonic acid group, and poly Crosslinked poly (meth) acrylate ester having an oxyalkylene group, crosslinked poly (meth) acrylamide, crosslinked copolymer of (meth) acrylate and (meth) acrylamide, hydroxyalkyl (meth) acrylate and ( Copolymerized cross-linked product with (meth) acrylate, polydioxolane cross-linked product, cross-linked polyethylene oxide, cross-linked polyvinyl pyrrolidone, sulfonated polystyrene cross-linked product, cross-linked polyvinyl pyridine, saponified product of starch-poly (meth) acrylonitrile graft copolymer, Starch-poly (meth) acrylic acid (salt) graft cross-linked copolymer, polyvinyl chloride Reaction products of alcohol and maleic acid (salt), cross-linked polyvinyl alcohol sulfonate, polyvinyl alcohol - acrylic acid graft copolymers, polyisobutylene maleic acid (salt) cross-linked polymer, and the like. Only one kind of these water-swellable resins may be used as necessary, or two or more kinds may be used in combination. Furthermore, other resins can be used in combination with the water-swellable resin to such an extent that various properties (such as the water absorption capacity) of the water-swellable resin are not impaired.
[0049]
Of the water swellable resins exemplified above, a water swellable resin having a nonionic group and / or a sulfonic acid (salt) group is more preferred, and a water swellable resin having an amide group or a hydroxyalkyl group is more preferred. Examples of the water-swellable resin include a crosslinked copolymer of (meth) acrylate and (meth) acrylamide, and a crosslinked copolymer of hydroxyalkyl (meth) acrylate and (meth) acrylate. Can be mentioned. Further, among the water swellable resins exemplified above, a water swellable resin having a polyoxyalkylene group is particularly preferable. Examples of the water-swellable resin include a crosslinked copolymer of (meth) acrylic acid ester having a methoxypolyoxyalkylene group and (meth) acrylate. The water-swellable resin having a methoxypolyoxyalkylene group is particularly excellent in water-swelling property exhibiting alkalinity over a long period of time. Therefore, by using the water-swellable resin, the operation of pulling out the temporary embedded object can be performed very easily.
[0050]
The “water exhibiting alkalinity” (hereinafter referred to as alkaline water) refers to water such as concrete water contained in a hydraulic composition such as concrete or mortar. Further, the pH of the alkaline water is not particularly specified.
[0051]
Furthermore, as the water-swellable resin according to the present invention, it is possible to use a resin obtained by polymerizing a monomer component containing an ethylenically unsaturated monomer having water solubility and, if necessary, a crosslinking agent. it can. A water-swellable resin obtained by (co) polymerizing an ethylenically unsaturated monomer is superior in water swellability and is generally inexpensive. Therefore, by using the water-swellable resin, the operation of pulling out the temporary embedded object can be performed very easily and more economically. In addition, said crosslinking agent is not specifically limited. Moreover, a water-swellable resin can also be formed by adding a crosslinking agent to a linear polymer for crosslinking, or by irradiation with an electron beam for crosslinking.
[0052]
Specific examples of the ethylenically unsaturated monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, vinyl sulfonic acid, and (meth) allyl sulfonic acid. 2- (meth) acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, and alkali metal salts and ammonium salts of these monomers; N , N-dimethylaminoethyl (meth) acrylate and quaternized products thereof; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N- Isopropyl (meth) acrylamide, (meth) acryloyl morpho (Meth) acrylamides such as ethylene, and derivatives of these monomers; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; polyethylene glycol mono (meth) Polyalkylene glycol mono (meth) acrylates such as acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate; N-vinyl-2-pyrrolidone, N-vinylsuccinimide N-vinyl monomers such as N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, etc. Monomer, vinyl methyl ether; but like, but it is not particularly limited. These ethylenically unsaturated monomers may be used alone or in combination of two or more.
[0053]
Of the ethylenically unsaturated monomers exemplified above, an ethylenically unsaturated monomer having a nonionic group and / or a sulfonic acid (salt) group is more preferred. Examples of the monomer include 2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, (meth) acrylamide, and hydroxyalkyl. (Meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate and the like can be mentioned. Furthermore, an ethylenically unsaturated monomer having a polyoxyalkylene group is particularly preferred. A water-swellable resin obtained by polymerizing a monomer component containing methoxypolyethylene glycol mono (meth) acrylate is particularly excellent in swellability with respect to alkaline water. Therefore, by using the water-swellable resin, the operation of pulling out the temporary embedded object can be performed very easily.
[0054]
Furthermore, when two or more types of ethylenically unsaturated monomers are used in combination as the monomer component, the ethylenically unsaturated group having a nonionic group and / or a sulfonic acid (salt) group in the monomer component The monomer ratio is more preferably 1% by weight or more, and further preferably 10% by weight or more. When the above ratio is less than 1% by weight, the workability of the work of pulling out the temporary embedded object can be further improved even by using a water-swellable resin obtained by polymerizing the monomer component. There is a risk of disappearing.
[0055]
As a more preferable combination when two or more ethylenically unsaturated monomers are used in combination as the monomer component, for example, a combination of an alkali metal salt of (meth) acrylic acid such as sodium acrylate and acrylamide, (meta ) A combination of an alkali metal salt of acrylic acid and methoxypolyethylene glycol mono (meth) acrylate is exemplified, but is not particularly limited.
[0056]
A water-swellable resin is obtained by polymerizing the above monomer components. The method for polymerizing the monomer component, that is, the method for producing the water-swellable resin is not particularly limited. Further, the average molecular weight and shape of the water-swellable resin, the average particle diameter, etc. may be set according to the composition of the hydraulic composition, the pH of the alkaline water, the combination with the sheet-like substrate, the working environment, etc. Although not limited, it is more desirable to use a water-swellable resin having an average particle size of 2,000 μm or less, more preferably 500 μm or less, and even more preferably 150 μm or less. By using the water-swellable resin having the average particle size, for example, the dispersibility or mixing property of the water-swellable resin in a resin solution (described later) becomes good, and thus the handling property is further improved, and the sheet shape A water-swellable resin layer adhered with a bonding agent can be easily formed on the substrate surface. Furthermore, the amount of the water-swellable resin attached to the sheet-like substrate per unit area can be increased in a uniform state.
[0057]
In the covering material according to the present invention, since the water absorbing material is attached to the sheet-like base material via the bonding agent, water is absorbed between the sheet-like base material and the cured product of the hydraulic composition. A swollen layer of water-absorbing material is formed. That is, since the layer of the swollen water-absorbing material can be formed between the temporarily embedded object and the cured product of the hydraulic composition, adhesion between the two can be further suppressed. Thereby, when pulling out a temporary burying thing from the hardened | cured material of a hydraulic composition, this temporary burying thing becomes easy to slip because the swollen water absorption material exhibits a lubricating effect. Therefore, since the labor (tensile force) in the operation of pulling out the temporary embedded object from the cured product of the hydraulic composition can be further reduced, the workability of the operation can be improved. Furthermore, by drying the water absorbing material, a gap can be formed between the temporary embedded object and the cured product of the hydraulic composition, so that the workability of the above work can be further improved.
[0058]
And, for example, when using a water-soluble resin as the bonding agent and using a water-swellable resin as the water-absorbing material, the ratio of both, that is, the ratio of the water-soluble resin and the water-swellable resin to be attached to the sheet-like substrate May be set according to the composition, combination, working environment and the like of both, and is not particularly limited, but is more preferably in the range of 1/99 to 99/1 by weight ratio. Within the range of / 10 is more preferable, and within the range of 25/75 to 75/25 is particularly preferable.
[0059]
In addition, the amount of water-soluble resin and water-swellable resin attached per unit area of the sheet-like substrate may be set according to the composition and combination of both, the work environment, etc., but is not particularly limited, 1g / m ² -10,000g / m ² Is more preferably within the range of 10 g / m ² ~ 5,000g / m ² Is more preferably within the range of 20 g / m ² ~ 1,000g / m ² The range of is particularly preferable. The ratio of the water-soluble resin and the water-swellable resin to 100 parts by weight of the sheet-like substrate is more preferably in the range of 1 part by weight to 10,000 parts by weight, and in the range of 10 parts by weight to 1,000 parts by weight. Is more preferable, and the range of 20 to 500 parts by weight is particularly preferable.
[0060]
In the case of using a bonding agent other than the water-soluble resin, the ratio between the bonding agent and the water-swellable resin, or the adhesion amount of the bonding agent and the water-swellable resin per unit area of the sheet-like substrate is What is necessary is just to set according to a composition, a combination, a working environment, etc., It does not specifically limit.
[0061]
The method for attaching the water-absorbing material to the surface of the sheet-like base material through the bonding agent is not particularly limited. Specifically, for example, the bonding agent and the water-swellable resin are dispersed in an organic solvent or water. A method of spraying a dispersion liquid dispersed in a medium onto the surface of a sheet-like substrate; a method of applying the dispersion liquid by brushing or using a roller; and impregnating the sheet-like substrate with the dispersion liquid Method; etc. may be adopted. Alternatively, a solution or dispersion containing a bonding agent is sprayed or applied to the surface of the sheet-like substrate, and then a water-swellable resin is uniformly distributed on the surface, and the solution or dispersion is further sprayed or applied thereon. Method; etc. can also be adopted. What is necessary is just to dry this dispersion liquid etc. which were apply | coated to the sheet-like base material as needed. As a result, the water-swellable resin is attached to the surface of the sheet-like substrate (outer surface and / or inner surface) via the bonding agent. That is, a water-swellable resin layer is formed. In addition, when forming the resin layer containing water-soluble resin on the sheet-like base material surface, the process of dispersing the water-swellable resin and the process of distributing the water-swellable resin in the above method may be omitted. Moreover, what is necessary is just to employ | adopt the method according to the said method, when using water absorbing materials other than water-swellable resin.
[0062]
The preparation method of the solution or dispersion containing the bonding agent and the water-swellable resin is not particularly limited. Specific examples of the organic solvent include methyl alcohol, ethyl alcohol, isopropyl alcohol, benzene, toluene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate; ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether. Examples thereof include, but are not limited to, polyhydric alcohols and derivatives thereof such as acetate and polypropylene glycol monomethyl ether acetate. The thickness of the layer containing the water-swellable resin is sufficient if it is about 10 μm, but it may be set according to the particle diameter of the water-swellable resin and is not particularly limited.
[0063]
And in the sheet-like base material, that is, the covering material, a layer of a water-absorbing material such as the water-swellable resin or a resin layer containing a water-soluble resin is provided on the outer surface in a state where the temporary embedded object is covered. More preferably, it is formed. As a result, the work of pulling out the temporary buried object can be performed more easily and, for example, the water-soluble resin dissolved in alkaline water is less likely to adhere to the temporary buried object, so that the surface of the removed temporarily buried object is cleaned. It can be kept in a stable state, and reuse (recycling) becomes easy.
[0064]
Furthermore, in the case of using a water-soluble resin as a bonding agent, in order to prevent the water-soluble resin from being dissolved by rain or the like, if necessary, on the surface of the layer containing the water-soluble resin (resin layer), A water-resistant film made of a water-resistance imparting agent can be formed (top coat).
[0065]
Examples of the water resistance-imparting agent include conventionally known water repellents such as wax, and alkali-soluble resins that dissolve in contact with an alkaline liquid, and combinations with water-soluble resins and water-absorbing materials. However, the selection is not particularly limited. The method for forming the water-resistant film is not particularly limited. Specifically, for example, a dispersion obtained by dispersing a water-resistance imparting agent in a dispersion medium such as an organic solvent or water is used as the resin layer. A method of spraying (spraying) on the surface; a method of applying a dispersion with a brush or a roller; a method of spraying or applying a melt of a water resistance-imparting agent; What is necessary is just to dry this dispersion liquid etc. which were apply | coated to the resin layer surface as needed. Thereby, a water-resistant film is formed on the resin layer surface. The film thickness of the water-resistant film is sufficient if it is about 50 μm, but is not particularly limited. For example, when a water-resistant film having a film thickness of 50 μm is formed, the coating amount of the water resistance-imparting agent is 50 g / m. ² The degree is not particularly limited.
[0066]
By forming a water-resistant film on the surface of the resin layer containing the water-soluble resin, it is possible to prevent the water-soluble resin from being dissolved even when it rains. Therefore, the performance is not impaired even during rainfall during work. Further, when constructing the structure, the temporary embedded object can be covered with a covering material at the work site. For example, the temporary embedded object is previously covered with the covering material, and the covered temporary embedded object Can also be piled up at the work site. Accordingly, it is not necessary to cover the temporary buried object with a waterproof sheet or to store it in an indoor material storage place or the like, so that the temporary buried object can be stored easily and inexpensively. That is, the work can be simplified and rationalized as appropriate according to the situation at the work site, so that the structure can be quickly constructed.
[0067]
In the state where the temporarily embedded object is covered with the covering material, the temporarily embedded object and the covering material are in contact with each other but not fixed. That is, the coating material according to the present invention is a non-adhesive (non-fixed) coating material. Therefore, a gap through which alkaline water can permeate is formed between the temporary buried object and the covering material. Therefore, the water-swelling property of the water-swellable resin is further improved, and the adhesion between the two is further suppressed. can do. And the operation | work which pulls out a temporary burying thing can be performed very easily by the synergistic effect with the lubrication effect by the swollen water-swellable resin.
[0068]
In addition, when covering a temporary embedded object with a covering material, it is desirable to use one covering material for one temporary embedded object, but if necessary, two or more for one temporary embedded object. It is also possible to use a coating material. Therefore, as a method of covering the temporarily embedded object with the covering material, for example, a method of sandwiching the temporarily embedded object between the two covering materials formed in a sheet shape can be employed. In the present invention, `` coating '' does not necessarily cover the temporary embedded object with the coating material so that the temporary embedded object can be easily extracted from the cured product of the hydraulic composition. That is, the temporary embedded object is covered with the covering material to such an extent that the adhesion between the two can be suppressed.
[0069]
Specifically, as a method of covering the temporary embedded object with the covering material, specifically, for example, a method of covering the temporary embedded object with the covering material formed in a bag shape or a cylindrical shape, and forming the temporary embedded object in a bag shape or a cylindrical shape A method of inserting into the coated covering material, a method of wrapping a temporary embedded object with a covering material formed in a sheet shape, and the like can be employed, but are not particularly limited.
[0070]
Further, when the temporary embedded object is covered with the covering material, it is more preferable to fix the covering material to the temporary embedded object using a fixing jig. Thereby, it becomes possible to coat the temporary embedded object with the covering material along its shape, and it is possible to more effectively suppress the contact between the temporary embedded object and the hydraulic composition, and to make the temporary embedded object a hydraulic composition. It is possible to improve the driving accuracy when driving into an object.
[0071]
In addition, as a method of forming the covering material into a bag shape or a cylindrical shape, specifically, for example, a method of bonding using an adhesive, a method of fusing by heat sealing, a method of sewing, binding with a wire or string, etc. Various methods such as a method can be adopted, but the method is not particularly limited. In addition, the packing form of the covering material is not particularly limited, but the state wound in a roll shape (FIG. 1) or the state folded in a bellows shape is from the viewpoint of handleability and workability. More preferable.
[0072]
The timing of covering the temporary buried object with the covering material is not particularly limited, and may be an appropriate time until the temporary buried object is carried to the work site. The temporary buried object is stored at the work site. It may be an appropriate time during the operation, or may be an appropriate time until the work for burying the temporary object is started. That is, the temporary burying object should just be coat | covered with the coating | covering material at the time of being embed | buried. Moreover, when using the coating | covering material formed in the bag shape or the cylinder shape, this coating | coated material should just be formed in these shapes at the time of being embed | buried.
[0073]
More specifically, for example, as shown in FIG. 1A, the temporary embedded object 2 is lifted up using a crane 6 and the tip of the crane 6 is covered with the covering material. A cord 3 passed through a pulley 5 provided on the belt is attached to the covering material 1, and then the covering material 1 formed in a bag shape or a cylindrical shape is put on from below by, for example, an operator 4 pulling the cord 3. Thus, after inserting in the temporary burying thing 2, as shown in the figure (b), the operator 4 pulls up the cord 3, and then the covering material 1 is pulled up and attached and fixed;
After the cylindrical covering material is covered from above and inserted into the temporary buried object and the upper end portion is fixed, the temporary embedded object is lifted using a crane, and then the string attached to the lower end portion of the covering material A method in which the covering material is pulled down by, for example, an operator pulling the covering material;
A method of placing a covering material formed in a bag shape or a cylindrical shape on the ground and the like, then inserting a temporary embedded object into the covering material, and then pulling up and mounting the covering material to fix it;
A method of inserting a covering material formed in a bag shape or a cylindrical shape into the temporary embedding object after placing the temporary embedding object on the ground, and then lifting the temporary embedding object and lifting the covering material to fix and fix ;
As shown in FIG. 2A, after the temporary burying object 2 is placed on the covering material 10 formed in a sheet shape using a crane 6 or the like, as shown in FIGS. 2B and 2C. Next, the temporary embedded object 2 is wrapped with the covering material 10, and then the covering material 10 is fixed using a fixing jig 11 as shown in FIG.
A method in which a temporary object is sandwiched and fixed between coverings folded in a bellows shape;
Fixing both ends of the covering material to the upper and lower parts of the temporary buried object;
A method of fixing both ends of the covering material to the upper and lower portions of the temporary buried object and fixing the central portion of the covering material using a wire (wire), string, belt, gum tape, etc .;
A method of fixing a part of the covering material to the upper part of the temporary embedded object and hanging the remaining part of the covering material along the temporary embedded object;
However, it is not particularly limited.
[0074]
Among the methods exemplified above, a method of inserting and attaching a covering material formed in a bag shape or a cylindrical shape into a temporary embedded object so as to be worn from below, and the temporary embedded object formed in a sheet shape A method of wrapping with a covering material is more preferable because it is excellent in workability of the covering operation. In addition, the method of fixing a coating | covering material to a temporary burying thing is not specifically limited. In addition, as the fixing jig 11, specifically, for example, a binder such as a cap formed by vertically dividing a tube such as a laundry clip, a clip, a rubber hose or a heat insulating foam, a wire (number wire), a string, A belt, a gummed tape, etc. are mentioned, but it is not particularly limited.
[0075]
As described above, by covering the temporary embedded object with the covering material, the temporary embedded object and the hydraulic composition can be prevented from coming into contact with each other, and both can be separated. The frictional resistance when the product is pulled out from the cured product can be reduced. Therefore, the temporary embedded object can be easily pulled out. The collected temporary buried object can be reused as it is. The covering material remains in the structure even after the temporary embedded object is pulled out. For example, when the covering material is fixed to the temporary embedded object, the covering material may be pulled out together with the temporary embedded object.
[0076]
In the above description, the covering material for covering the temporary embedded object used in the structure constituted at least by the temporary embedded object and the cured product of the hydraulic composition has been described as an example. The covering material can also be applied to a temporary embedded object embedded in soil. As a result, it is possible to reduce the frictional resistance when the temporary embedded object is extracted from the soil, and the temporary embedded object can be easily extracted.
[0077]
Moreover, the structure by which the said resin layer is formed in the surface which becomes an outer side in the state which coat | covered the temporary burying thing can also be employ | adopted for the coating | covering material of this invention. According to the above configuration, the operation of pulling out the temporary buried object can be performed more easily, and the water-soluble resin dissolved in water does not adhere to the temporary buried object. Can be kept clean and can be easily reused (recycled).
[0078]
The covering material of the present invention can further employ a configuration in which the bonding agent is a water-soluble resin. According to said structure, for example, when the said temporary embedment is covered with a covering material in order to pull out the temporary embedment from the cured product of the hydraulic composition, the water-soluble resin is contained in the water contained in the hydraulic composition. Therefore, there is no possibility of hindering volume expansion when the water absorbing material swells by absorbing water. Therefore, the water-absorbing material can sufficiently exhibit its water-absorbing characteristics (performance). Thereby, since the labor (tensile force) in the operation | work which pulls out a temporary embedment from the hardened | cured material of a hydraulic composition can be reduced further, the workability | operativity of this operation | work can be improved.
[0079]
The covering material of the present invention may further employ a configuration in which the water absorbing material is a water-swellable resin. According to said structure, the swelled water-swellable resin exhibits a lubricating effect, so that the temporary embedded object becomes even more slippery. Therefore, the workability of the work of pulling out the temporary buried object can be further improved.
[0080]
The covering material of the present invention may further employ a configuration in which the average particle size of the water-swellable resin is 2,000 μm or less. According to the above configuration, the mixing property of the bonding agent such as a water-soluble resin and the water-swellable resin becomes better, and the adhesion amount of the water-swellable resin per unit area of the sheet-like base material Compared to the case where the diameter exceeds 2,000 μm, the number can be increased, and the resin layer can be more easily formed. Therefore, the pullability of the temporary embedded object and the workability of the pulling work can be further improved.
[0081]
The covering material of the present invention can further employ a configuration in which the water-absorbing material adheres to the outer surface in a state where the temporarily embedded object is covered. According to the above configuration, the work of pulling out the temporary buried object can be performed more easily, and the water absorbing material and the bonding agent do not adhere to the temporary buried object. It can be kept in a stable state, and reuse (recycling) becomes easy.
[0082]
The covering material of the present invention can also employ a configuration in which the sheet-like base material has a tensile strength of 1 kgf / 2.5 cm or more. According to said structure, the coating | covering material provided with the intensity | strength which is not damaged even if external force, such as an impact force produced when embed | buying a temporary burying object, tensile force, etc. is applied, can be provided.
[0083]
The covering material of the present invention may further adopt a configuration formed in a bag shape or a cylindrical shape into which a temporary embedded object can be inserted. According to said structure, a temporary burying thing can be coat | covered still more easily and rapidly.
[0084]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these.
[0085]
[Example 1]
A water-swellable resin was produced by crosslinking and copolymerizing sodium acrylate and acrylic acid under predetermined conditions. The average particle size of the water-swellable resin was 100 μm.
[0086]
And on the surface (single side) of the woven fabric (sheet-like substrate, polyester: cotton / 50: 50 (weight ratio), basis weight 200 g, thickness 0.5 mm) cut to the size of A4 plate, as solid content 1.25 g of starch paste (6% by weight aqueous solution, water-soluble resin) was sprayed uniformly. On top of this, 5.0 g of the water-swellable resin was evenly spread, and further, 1.25 g of starch paste as a solid content was evenly sprayed thereon. Next, the woven fabric to which the water-swellable resin was adhered was dried at 120 ° C. for 15 minutes using a dryer. That is, a layer containing a water-swellable resin and starch was formed on one side of the woven fabric. The woven fabric has a starch of 40 g / m ² Water-swellable resin is 80g / m ² It was attached at a rate of. Further, the tensile strength of the woven fabric showed an extremely high value of 30 kgf / 2.5 cm.
[0087]
Next, the woven fabric in which a layer containing a water-swellable resin and starch is formed, that is, the covering material according to the present invention is sewn so that the layer is on the outside, and the width is 80 mm × height is 140 mm. A bag was formed. An iron plate (manufactured by Nippon Test Panel Osaka Co., Ltd.) having a width of 70 mm, a height of 150 mm and a thickness of 0.8 mm as a temporary embedded object was inserted into the bag.
[0088]
On the other hand, soil cement milk (hydraulic composition) was prepared by mixing water, cement, clay and bentonite in a weight ratio of 25: 12: 16: 0.6. And the said bag body was embedded in the soil cement milk put into the container. That is, after the iron plate coated with the coating material was driven into the soil cement milk, the soil cement milk was cured.
[0089]
Three days after the iron plate was driven, the iron plate was pulled out from the cured product of the soil cement milk using a tensile tester. The drawing load required for the drawing operation was 0.9 kgf, and the iron plate could be drawn very easily from the cured product of the soil cement milk.
[0090]
[Comparative Example 1]
The same operation as that of Example 1 was performed to prepare a covering material. Next, this covering material was attached to both surfaces of an iron plate having a width of 70 mm, a height of 150 mm, and a thickness of 0.8 mm using an adhesive. That is, the covering material was directly fixed to both surfaces of the iron plate.
[0091]
Next, the same iron plate as described in Example 1 was embedded in the soil cement milk. That is, after the comparative iron plate with the covering material fixed thereto was driven into the soil cement milk, the iron plate was pulled out from the cured product of the soil cement milk. The drawing load required for the drawing operation was 5.0 kgf, and the iron plate could not be easily drawn from the cured product of the soil cement milk.
[0092]
[Example 2]
A covering material was produced using a synthetic rubber-based bonding agent (manufactured by Sumitomo 3M Co., Ltd .; trade name “3M spray paste 99”) instead of the water-soluble resin. The components of the bonding agent are 10% by weight of a synthetic rubber such as styrene butadiene rubber, 40% by weight of an organic solvent such as n-pentane, acetone or toluene, and 50% by weight of a gas (for spraying) such as LPG or dimethyl ether.
[0093]
First, a water-swellable resin was produced by crosslinking and copolymerizing sodium acrylate and acrylamide under predetermined conditions. The average particle size of the water-swellable resin was 200 μm.
[0094]
Then, the bonding agent was sprayed uniformly on the surface (one side) of the non-woven fabric cut to the size of A4 plate so that the amount of the synthetic rubber (solid content) adhered was 0.5 g. On top of that, 2.5 g of the water-swellable resin was evenly spread, and on this, the bonding agent was evenly sprayed so that the amount of the synthetic rubber deposited was 1.5 g. And the operation similar to the said operation was performed also on the back surface of this nonwoven fabric, and water swellable resin was made to adhere with a synthetic rubber. Next, the nonwoven fabric to which the water-swellable resin was adhered was dried at 100 ° C. for 5 minutes using a dryer. The nonwoven fabric has a synthetic rubber of 64 g / m. ² Water-swellable resin is 80g / m ² It was attached at a rate of.
[0095]
Next, by performing the same operation as that of Example 1, the iron plate covered with the bag-shaped coating material was driven into the soil cement milk, and then the iron plate was pulled out from the cured product of the soil cement milk. The drawing load required for the drawing work was 3.0 kgf, and the iron plate could be easily drawn from the cured product of the soil cement milk.
[0096]
[Comparative Example 2]
The synthetic rubber-based adhesive used in Example 2 was sprayed uniformly on one side of an iron plate having a width of 70 mm, a height of 150 mm, and a thickness of 0.8 mm so that the amount of adhesion was 0.5 g. On top of that, 2.5 g of the water-swellable resin produced in Example 2 was evenly spread, and further on this, the bonding agent was evenly sprayed so that the amount of synthetic rubber adhered was 1.5 g. . And the operation similar to the said operation was performed also on the back surface of this iron plate, and water swellable resin was made to adhere with a synthetic rubber. Next, the iron plate was dried at 100 ° C. for 5 minutes using a dryer. On the iron plate, synthetic rubber is 64 g / m ² Water-swellable resin is 80g / m ² It was attached at a rate of.
[0097]
Next, by performing the same operation as in Example 1, an iron plate not covered with the bag-like coating material according to the present invention was driven into the soil cement milk, and then the iron plate was cured from the soil cement milk. Pulled out from. The drawing load required for the drawing operation was 7.0 kgf, which was larger than the result of Example 2 above, and the iron plate could not be easily drawn from the cured soil cement milk.
[0098]
Example 3
As a solid content on the surface (one side) of a woven fabric (sheet-like substrate, polyester: cotton / 65: 35 (weight ratio), basis weight 150 g, thickness 0.4 mm) cut to the size of A4 plate. The aqueous solution of polyvinyl alcohol was uniformly sprayed so that 25 g of 88% saponified polyvinyl alcohol (trade name Kuraray Poval PVA-217, water-soluble resin) was adhered.
[0099]
Furthermore, 5.0 g of a water-swellable resin (average particle size 100 μm) produced by crosslinking and copolymerizing sodium acrylate and acrylic acid under predetermined conditions is uniformly distributed, and further, The aqueous solution of polyvinyl alcohol was uniformly sprayed so that 1.25 g of 88% saponified polyvinyl alcohol adhered as a solid content. Next, the woven fabric to which the water-swellable resin was adhered was dried at 120 ° C. for 40 minutes using a dryer. That is, a layer containing a water-swellable resin and polyvinyl alcohol was formed on one side of the woven fabric. The woven fabric contains 88% saponified polyvinyl alcohol at 40 g / m. ² Water-swellable resin is 80g / m ² It was attached at a rate of. Further, the tensile strength of the woven fabric was as extremely high as 52 kgf / 2.5 cm.
[0100]
Next, the woven fabric in which a layer containing a water-swellable resin and 88% saponified polyvinyl alcohol is formed, that is, the covering material according to the present invention, is sewn so that the layer is on the outside, and the width is 80 mm × A bag body having a height of 140 mm was formed. An iron plate (manufactured by Nippon Test Panel Osaka Co., Ltd.) having a width of 70 mm, a height of 150 mm and a thickness of 0.8 mm as a temporary embedded object was inserted into the bag.
[0101]
Next, by performing the same operation as that of Example 1, the iron plate covered with the bag-shaped coating material was driven into the soil cement milk, and then the iron plate was pulled out from the cured product of the soil cement milk. The drawing load required for the drawing operation was 0.7 kgf, and the iron plate could be easily drawn from the cured product of soil cement milk.
[0102]
Example 4
The polymer drop-off rate test of the coating material according to the present invention, that is, the polymer drop-off rate test attached to the woven fabric was performed. First, based on the coating material and the preparation method described in Example 3, the following three types of samples were prepared as samples for the drop-off rate test. In addition, the polymer in a present Example shows what combined water-soluble resin (bonding agent) and water swelling resin (water-absorbing material).
[0103]
A. The adhesion amount of 88% saponified polyvinyl alcohol is 80 g / m. ² A sample {circle around (1)} was prepared in the same manner as in Example 3 except that (one side) was selected.
[0104]
I. Instead of 88% saponified polyvinyl alcohol, completely saponified polyvinyl alcohol was used, and the adhesion amount was 80 g / m. ² A sample {circle around (2)} was prepared in the same manner as in Example 3 except that (one side) was selected.
[0105]
C. Instead of 88% saponified polyvinyl alcohol, starch paste is used, and the adhesion amount is 80 g / m. ² A sample (3) was produced in the same manner as in Example 3 except that (one side) was selected.
[0106]
Then, after putting the above three kinds of samples (1) to (3) cut into 5 cm × 5 cm in a 100 ml container into which ion-exchanged water has been poured and immersed for 5 minutes, these samples (1) to (1) (3) was lifted from the ion-exchanged water, and after removing excess water, it was dried.
[0107]
Next, the amount of polymer dropped from the woven fabric was measured from the change in weight of the sample before and after being dipped (after drying) in ion-exchanged water, and the amount of polymer (g) dropped off was determined as ion-exchanged water. The dropout rate (%) was calculated by dividing by the total polymer amount (g) adhering to the woven fabric before dipping in the fabric. That means

The dropout rate (%) indicated by is calculated.
[0108]
As a result, the dropout rates of the samples (1) to (3) were 28.5%, 11.6%, and 70.9% in this order. Therefore, among water-soluble resins (bonding agents), polyvinyl alcohol is more effective in preventing the water-swellable resin (water-absorbing material) from falling off the woven fabric (sheet-like substrate) before or during construction. It turned out to be even better.
[0109]
【The invention's effect】
As described above, the covering material according to claim 1 of the present invention is a covering material that covers a temporary embedded object in a non-adhesive state, and a resin layer containing a water-soluble resin is formed on a sheet-like base material. It is the composition which is.
[0110]
According to said structure, since an easily peelable layer can be formed between a sheet-like base material and the hardened | cured material of a hydraulic composition, when a water-soluble resin melt | dissolves, a temporary embedding thing is a hydraulic composition. The labor (tensile force) in the work of pulling out the cured product can be reduced, and the workability of the work can be improved. Therefore, according to said structure, there exists an effect that the coating | covering material which can improve the operation | work which pulls out a temporary burying thing can be provided.
[0111]
As described above, the covering material according to claim 2 of the present invention is a covering material that covers a temporary embedded object in a non-adhered state, and is composed of a sheet-like base material, a water absorbing material, and the water absorbing material. And a bonding agent attached to the material.
[0112]
According to said structure, since the layer of the swollen water-absorbing material can be formed between a temporary embedding thing and the hardened | cured material of a hydraulic composition, adhesion of both can be suppressed further. Thereby, when pulling out a temporary burying thing from the hardened | cured material of a hydraulic composition, this temporary burying thing becomes easy to slip because the swollen water absorption material exhibits a lubricating effect. Therefore, since the labor (tensile force) in the work of pulling out the temporary embedded object from the cured product of the hydraulic composition can be further reduced, the workability of the work can be improved. Furthermore, by drying the water absorbing material, a gap can be formed between the temporary embedded object and the cured product of the hydraulic composition, so that the workability of the above work can be further improved. Play together.
[0113]
As described above, the covering material according to claim 3 of the present invention is configured such that the water-soluble resin or the bonding agent is a water-soluble resin having a drop-off rate of 50% or less from the sheet-like base material.
[0114]
According to said structure, since it can suppress further that water-soluble resin (or bonding agent) falls from a sheet-like base material before construction or during construction, a sheet-like base material and a hydraulic composition of A sufficient easy peeling layer can be formed between the cured product. Therefore, it is possible to reduce the labor (tensile force) in the work of pulling out the temporarily embedded object from the cured product of the hydraulic composition, and to improve the workability of the work.
[0115]
As described above, the sheet-like flexible material according to claim 4 of the present invention includes at least a water-soluble resin and a water-absorbing material in the sheet-like substrate, and the drop-off rate from the sheet-like substrate is 50%. It is the structure in which the following resin layers are formed.
[0116]
According to said structure, there exists an effect that the sheet-like flexible material suitable for coat | covering various articles | goods can be provided, for example.
[Brief description of the drawings]
FIGS. 1A and 1B are schematic perspective views showing a procedure for covering a temporary embedded object using a covering material according to an embodiment of the present invention.
FIGS. 2A to 2D are schematic perspective views showing a procedure for covering a temporary embedded object with a covering material according to another embodiment of the present invention.
[Explanation of symbols]
1 Coating material
2 Temporary buried objects
10 Coating material

Claims (3)

A covering material that covers a temporary buried object in a non-adhesive state,
A covering material, wherein a resin layer containing a water-soluble resin is formed on a sheet-like base material having a tensile strength of 1 kgf / 2.5 cm or more . A covering material that covers a temporary buried object in a non-adhesive state,
A covering material comprising a sheet-like base material having a tensile strength of 1 kgf / 2.5 cm or more, a water-absorbing material, and a bonding agent for adhering the water-absorbing material to the sheet-like base material.   The covering material according to claim 1 or 2, wherein the water-soluble resin or the bonding agent is a water-soluble resin having a drop-off rate of 50% or less from the sheet-like base material.

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