JP4104880B2

JP4104880B2 - Inorganic board and method for producing the same

Info

Publication number: JP4104880B2
Application number: JP2002061320A
Authority: JP
Inventors: 崇山根; 博油原
Original assignee: Nichiha Corp
Current assignee: Nichiha Corp
Priority date: 2002-03-07
Filing date: 2002-03-07
Publication date: 2008-06-18
Anticipated expiration: 2022-03-07
Also published as: JP2003251618A

Description

【０００１】
【発明が属する技術分野】
本発明は、外壁材や屋根材等の建築材料に用いられる無機質板及びその製造方法に関するものである。
【０００２】
【従来の技術】
この種の無機質板はセメントなどの水硬性材料と、パルプなどの補強繊維物質とを主体とする原料混合物を水に分散させてスラリーとした後、透水性シート上に原料混合物を流下させマット状にし、プレス装置にて脱水成形した後、養生硬化し乾燥することによって製造される。これらの無機質板は未硬化のマットをプレス装置により脱水成形することにより、柄模様のないフラットな平板や、時には実部を有した未硬化板を一体的に成形し製造される。そしてこの方法以外にも、無機質板表面には立体的な変化をもたせるためにエンボス柄模様を付与することが行われている。このエンボス柄模様を付与するためには、マットを押圧脱水成形する際に、表面に柄模様を形成した型板を取り付けたプレス装置を使用することで、押圧脱水成形と同時にエンボス柄模様が一体的に形成される方法が通常行われており、無機質板に様々な柄模様を付与することが行われている。
【０００３】
また最近では、無機質板表面に深いエンボス柄模様を得るために、セメントなどの水硬性材料とパルプなどの補強繊維物質とを主体とする原料混合物を水に分散させたスラリーを透水性シート上に層状に散布し、更にその上面に別配合の原料混合物を層状に散布後プレス成形する複層タイプの無機質板が提供されている。このような深いエンボス柄模様を得るための方法として、表層原料の含水率を４０％以下とし軽量骨材を特定範囲の割合で配合した粉体原料を散布積層し押圧成形することで表面に深いエンボス柄模様を付することが行われている。（特開昭６１−１４９３１２）
また、製品表面を平滑で緻密な表面性にするために、粉体材料を表層原料上に散布する方法として、粒子径の小さい粉体セメントを散布してから押圧成形することで表層部を緻密にする方法がとられている。（特開平６−１９０８１８）
【０００４】
【発明が解決しようとする課題】
しかしながら前述した従来例によると、未硬化の無機質系板材の表面にある程度の深さのエンボス模様をプレスを用いて付与することができるが、表層に用いられる原料は含水率が少なく流動性が不足しているため、特に表面に柄模様を形成した型板を取り付けたプレス装置にて成形した場合には、プレス時に無機質板の凸部を構成する部分に対応するエンボス模様型板の凹部分に原料が移動しにくく表面にポーラスな部分が発生しやすくなる。その結果、ポーラスな部分の表面にはピンホール、いわゆる素穴が発生することが多く、この素穴により無機質板の表面性状は不十分になる。仮に無機質板を外壁材に用いた場合、この素穴から降雨などによる吸水が生じやすくなるため、無機質板の耐透水性能に悪影響を及ぼすといった問題点を有していた。この素穴は表面の緻密さや意匠性を低減させるばかりでなく、透水量が増えることで吸水乾燥の伸び縮みによるクラックの発生や凍結融解性能の悪化など製品の耐久性を著しく悪化させていた。
【０００５】
また、透水性シートに載置された型枠内にスラリーを流下して基層を形成する際、原料が均一に混合されていないと板内に散布ムラが発生しやすく、通常よりも薄く散布された箇所がポーラスになるために押圧成形後の表面にピンホール状の素穴が発生しやすくなる。また、ペースト状のスラリーである基層原料は表層原料を散布する前にある程度の脱水を行い保型可能なようにマット状にしているが、この基層材料の脱水が不十分な場合などには、マットは柔らかい状態であるため、表層原料が散布された際に表層原料が基層原料の中に入り込んでしまい、含水率の高い基層原料が表層面に割り出てしまう逆転現象が生じてしまい、その部分だけ脱水不良となりピンホール状の素穴が発生しやすい。
【０００６】
この現象を無くすために、表層の粉体原料に多量の水分を含有させて押圧成型時の流動性を向上させる手段がとられているが、粉体原料は混合時に過剰の水分を混入すると、補強繊維物質が玉状に凝集しやすく、また成型時において脱水に時間がかかり生産性を悪化させ、また脱水が不十分であるとその部分の表面性が低下するという問題点があった。さらにまた、無機質板表面に塗装を施すことによって耐透水性を改善する手段がとられるが、素穴を完全に隠すためにはある程度の塗布量が必要になり原板の耐透水性を向上させるには塗装費用が増加してしまうという問題点を有していた。
また、製品表面を緻密にするために、粉体材料を表層原料上に更に散布する手段がとられているが、粒子径の小さい原料を表層に散布するので、成形後の型板表面に細かい粉体材料が付着されやすく、成型品の表面性をかえって悪化させてしまうこと、また粒子径の小さい原料を散布するために新規の設備が必要となるため製造設備が大がかりなものとなり、製造コストを上昇させてしまうなどの問題点を有していた。すなわち、これまで過剰な塗装の必要がなく、また製造コストを上昇させることなく無機質板表面に素穴のない平滑さや緻密さを生じさせ、特に無機質板の耐透水性能を向上させることはその性能上重要な課題であった。本発明は上記課題を解決するためになされたものであり、基層マットの表面に表層原料を散布して押圧脱水成形して得られる無機質板とその製造方法において、過剰な塗装を施すことなく無機質板製品の表面性を向上させ、生産性を向上させる無機質板及びその製造方法を提供することを目的とするものである。
【０００７】
【課題を解決するための手段】
本発明は上記目的を達成するために、本請求項１ではセメントと補強繊維物質とを主成分とするスラリーを透水性シート上に載置された型枠内に流下した後脱水して基層を形成し、該基層の上面にセメントと補強繊維物質とを主成分とする粉体混合物を散布積層し、脱水成形後養生硬化して得られる無機質板であって、該基層には軽量骨材、無機質板リサイクル原料、補強繊維物質とを含有したスラリーとし、該基層の上面にセメントと補強繊維物質とを主成分とする粉体混合物を散布積層して得られる無機質板を提供するものである。上記構成によれば、軽量骨材、無機質板リサイクル原料、補強繊維物質とを含有したスラリーは嵩高くなるので圧締時の圧力が高くなり、あいともなって表層に高い圧締圧力が均一に及ぶことになり、またエンボス模様を押圧成形する際、表面にエンボス模様を形成した型板の凹部に原料が移動しやすくなるために、表層材料が緻密になり素穴のない無機質板となる。また、基層原料は嵩高いために混合時に分散されやすく均一なスラリーとなるので、型枠内に流下したスラリーは厚みムラがなくなる。また、基層は嵩高くなることで脱水孔が増加したポーラスなスラリーとなるので生産性が向上することになり、また基層は確実に保型性のあるマットとなるので、基層マット上に散布した表層原料は基層にめり込んでしまうことがなくなり、押圧脱水成形後の無機質板表面はピンホール状の素穴のないものとなる。
【０００８】
また、本請求項２ではセメントと補強繊維物質とを主成分とするスラリーを透水性シート上に載置された型枠内に流下した後脱水して基層を形成し、該基層の上面にセメントと補強繊維物質とを主成分とする粉体混合物を散布積層し、脱水成形後養生硬化せしめる無機質板の製造方法であって、該基層には軽量骨材、無機質板リサイクル原料、補強繊維物質とを含有したスラリーを型枠内に流下し、該スラリーの上面にセメントと補強繊維物質とを主成分とする粉体混合物を散布積層することを特徴とする無機質板の製造方法について提供するものである。上記構成によれば、基層を構成する原料は嵩高くなるために圧締する際の圧力が高くなり、あいともなって表層に高い圧締圧力が均一に及ぶため、またエンボス模様を押圧成形する際、エンボス模様のある型板の凹部に原料が移動しやすくなるため、表層材料が緻密になり素穴をなくした無機質板を容易に製造することが可能となる。また、基層原料は嵩高いために混合時に分散されやすく均一なスラリーとなるので、型枠内に流下したスラリーは均一な厚みに流下することができる。また、基層は嵩高くなることにより脱水孔が増えるので、濾水性を向上させることができ生産性よく無機質板を製造することができ、また基層マットにある程度の保型性があり、基層マット上に散布した表層原料は基層にめり込んでしまうことがなく、表層を確実に均一な厚さで散布積層することができるので、表面性が良好な無機質板を製造することができる。
【０００９】
【発明の実施の形態】
本発明の実施形態を以下に詳細に説明する。
本発明に係わる無機質板は基層と表層から構成されており、セメントなどの水硬性材料とパルプなどの補強繊維物質とを主体とする原料混合物を水に分散させたスラリーを透水性シート上に層状に流下し脱水形成されるマットを基層とし、更にその上面にセメントなどの水硬性材料とパルプなどの補強繊維物質とを主成分とする別配合の粉体原料混合物を層状に散布した原料を表層とし、押圧脱水成形することによって得られる無機質板である。ここで、水硬性材料としては、例えばポルトランドセメント、高炉スラグセメント、シリカセメント、フライアッシュセメント、アルミナセメント等がある。また、補強繊維物質としては、例えば木片、木質パルプ、木質繊維束、木毛、木粉、合成繊維等が使用されるが、ポリエステル繊維、ポリアミド繊維、アクリル繊維、ポリ塩化ビニリデン繊維、アセテート繊維等の有機繊維、あるいはセピオライト、ワラストナイト、ガラス繊維等の無機繊維が使用されてもよい。
【００１０】
更に本発明では上記成分以外に、例えばケイ砂、ケイ石粉、シリカヒューム、高炉スラグ、フライアッシュ、シラスバルーン、パーライト、ベントナイト、ケイ藻土等のケイ酸含有物質等の無機充填材、塩化カルシウム、塩化マグネシウム、塩化鉄、塩化アルミニウム、塩化ナトリウム、塩化カリウム、塩化リチウム等の塩化物の無水物あるいは結晶化物、硫酸アルミニウム、ミョウバン、硫酸鉄、硫酸リチウム、硫酸ナトリウム、硫酸カリウム、硫酸マグネシウム等の硫酸塩の無水物あるいは結晶化物、硝酸カルシウム、亜硝酸カルシウム等の硝酸塩、亜硝酸塩の無機物あるいは結晶化物、ギ酸カルシウム、酢酸カルシウム等のギ酸塩、酢酸塩の無水物あるいは結晶化物、アルミン酸ソーダ、水ガラス等のセメント硬化促進剤やワックス、パラフィン、シリコン等の撥水剤、発泡ポリスチレンビーズ等の発泡性熱可塑性プラスチックビーズ等が添加されてもよい。
【００１１】
本発明の無機質板を製造するには、上記原料の混合物を水に分散せしめてスラリーとし、該スラリーを透水性シート上に供給して該シート裏面から吸引脱水してマットをフォーミングし、その上面に粉体原料を層状に散布し、押圧脱水成形した後養生硬化せしめる方法が採用される。無機質硬化層のうち基層に使用される原料として望ましくはセメント類とケイ酸含有物質とが使用され、該セメント類と該ケイ酸含有物質との合計量が該基層原料中に６０〜９５重量％になるように添加され、そして該セメント類と該ケイ酸含有物質との比率は通常重量比で７０：３０〜３０：７０とされる。該基層原料中に分散せしめる補強繊維物質は、通常原料中に５〜１５重量％の量で添加され、合成繊維を添加する場合は通常原料中に５重量％以下の量で添加される。ケイ酸含有物質はセメントとケイ酸カルシウム反応により無機質板の硬化を円滑且つ完全に行わしめるものであり、得られる製品の寸法安定性が良好になる。
【００１２】
更に、本発明においては軽量骨材、無機質板リサイクル原料、補強繊維物質の嵩比重が低い原料を含有し、嵩高いスラリーを生成する。軽量骨材を添加する場合は、該軽量骨材は通常原料中に１〜１５重量％、また無機質板リサイクル原料を添加する場合は通常原料中に１〜２０重量％、としたものを使用するのが望ましい。これら原料は製造される無機質板の重量を軽減し且つスラリーを嵩高くせしめるので、本発明にとって必須成分であるが、含有量が該混合物中必要量以上になると低比重化や補強繊維物質の凝集により得られる無機質板の強度が低下しやすい。
【００１３】
一方、無機質硬化層のうち表層は若干の水分が添加された半乾式の粉体原料混合物であり、基層の上面に載せて形成されるものである。該表層は基層と同様にセメント類と補強繊維物質を主成分とし、望ましくは該セメント類と該ケイ酸含有物質とが使用され、セメント類とケイ酸含有物質との合計量が６０〜９５重量％になるように添加され、そして該セメント類と該ケイ酸含有物質との比率は通常重量比で７０：３０〜３０：７０とされる。また、該表層原料中に分散せしめる補強繊維物質は０〜１０重量％、軽量骨材は０〜７重量％を使用するのが望ましい。また、基層と表層の各散布量について基層スラリーは全固形分に対して７０〜９５％、表層粉体原料は５〜３０％とするのが望ましい。
【００１４】
本発明に係る無機質板の製造設備は図２に示すように、基層スラリー流込装置２、表層粉体散布装置３、押圧脱水成型装置４、可動式の透水性シート５、吸引脱水装置８、搬送ベルト９などから構成されている。
すなわち、基層スラリー流込装置２はスラリー貯留槽２１を具備しており、表層粉体散布装置３は粉体混合物貯留槽２２を具備しており、また吸引脱水装置８は吸引機を具備している。他方、押圧脱水装置４はプレス５１を有しており、このプレス５１は上盤５２および下盤５４を備えている。ここで、下盤５４は吸引脱水装置を備えプレス５１本体に固定されているのに対し、上盤５２には表面に柄模様が形成されたエンボス型板５３が固着され、それらは昇降駆動自在に支持されている。これら、スラリー流込装置２、表層粉体散布装置３、押圧脱水成型装置４、吸引脱水装置８を順次つなぐ形で透水性シート５が回転駆動自在に張設されており、この透水性シート５の近傍には搬送用のベルト９が回転駆動自在に張設されている。
【００１５】
基層原料は通常含水率３００〜４００％となるよう水が添加混合されてスラリーとされる。該混練されたスラリーはメッシュ状の透水性シート５上に載置された型枠１０内に所定量流し込み供給され、該スラリーを均した後、透水性シートの裏面から吸引脱水装置８の吸引機を駆動して、該スラリーの下面から吸引脱水する。脱水後、スラリーの含水率は保型がなされる程度の含水率に低減しており、通常含水率が１５０〜２００％の平板状のマット１１が型枠内に形成される。その後、透水性シート５を回転させて表層原料散布装置３近傍に移送し、基層マット上に粉体原料１２が均一に散布される。ここで、粉体原料の散布率は基材の固形分に対して５〜３０重量％とすることが望ましい。
表層を散布した後、型枠１０を取り外してマットのみを透水性シート上に残し、透水性シート５を回転移動させてマットを押圧脱水成型装置４近傍に移送した後、押圧脱水成型装置の上盤５２と下盤５４との間に位置決めされた状態で、上盤を所定のストロークだけ下降させる。このような押圧脱水成型装置によりプレスされることにより板状に脱水成型され、所望なれば上盤に固着された型板５３によりマット表面に柄模様が付される。
このように製造された無機質板は養生工程に移行し硬化せしめられるが、養生の前または後に所定寸法に切抜かれる。養生は該マットを密閉室内で通常６〜３０時間非加熱あるいは加熱常圧下に放置して一次硬化させ、その後通常１６０〜１８０℃、６〜１５時間オートクレーブ養生を行ない完全に硬化させる二段養生法が用いられる。養生硬化後は該マット硬化物は所望なればトリミング、塗装等を施され無機質板製品とされる。
【００１６】
【実施例】
以下、本発明の実施例について説明する。
実施例１
基層用原料として下記組成の原料混合物を調整する。
ポルトランドセメント４０重量％、ケイ石粉３９重量％、パーライト６．７重量％、無機質板リサイクル原料６．７重量％、パルプ６．７重量％、合成繊維１重量％とし、上記原料混合物を水と混合して均一攪拌することによって含水率３００％になるようにスラリーを調整する。上記原料スラリーを透水性シート上に載置した型枠に流し込み、均し、スラリーの含水率が１５０％になるように透水性シート下面に設置された吸引脱水装置にて一定時間脱水する。
【００１７】
他方、表層用原料として下記組成の原料混合物を調整する。
ポルトランドセメント４２重量％、ケイ石粉４２重量％、パーライト７重量％、無機質板リサイクル原料５重量％、パルプ３重量％、合成繊維１重量％とし、含水率が２０％になるように水を添加して粉体原料を得る。
そして、この粉体原料を基層上に全固形分に対して２５％散布し、これを設定厚さになるよう表面に柄模様を形成した型板を取り付けたプレス装置にて加圧脱水成形する。このようにして成形されたマットは、６０〜８０℃、６〜３０時間の一次養生およびオートクレーブ中１６０〜１８０℃、６〜１５時間の二次養生を行って所定の無機質板が得られる。
【００１８】
実施例２
基層用原料の組成を下記に調整する。
ポルトランドセメント３５重量％、ケイ石粉３４重量％、パーライト１０重量％、無機質板リサイクル原料１０重量％、パルプ１０重量％、合成繊維１重量％としスラリーを調整する。その他は実施例１で使用した条件と同様にして、無機質板を製造する。
実施例３
基層用原料の組成を下記に調整する。
ポルトランドセメント３５重量％、ケイ石粉３４重量％、パーライト５重量％、無機質板リサイクル原料１５重量％、パルプ１０重量％、合成繊維１重量％としスラリーを調整する。その他は実施例１で使用したものと同様にして、無機質板を製造する。
実施例４
基層用原料の組成を下記に調整する。
ポルトランドセメント３５重量％、ケイ石粉３４重量％、パーライト１０重量％、無機質板リサイクル原料５重量％、パルプ１５重量％、合成繊維１重量％としスラリーを調整する。その他は実施例１で使用したものと同様にして、無機質板を製造する。
比較例１
基層用原料として下記組成の原料混合物を調整する。
ポルトランドセメント４０重量％、ケイ石粉３９重量％、無機質板リサイクル原料１０重量％、パルプ１０重量％、合成繊維１重量％としスラリーを調整する。その他は実施例１で使用したものと同様にして、無機質板を製造する。
比較例２
基層用原料として下記組成の原料混合物を調整する。
ポルトランドセメント４０重量％、ケイ石粉３９重量％、パーライト１０重量％、パルプ１０重量％、合成繊維１重量％としスラリーを調整する。その他は実施例１で使用したものと同様にして、無機質板を製造する。
比較例３
基層用原料として下記組成の原料混合物を調整する。
ポルトランドセメント４０重量％、ケイ石粉３９重量％、パーライト５．５重量％、無機質板リサイクル原料５．５重量％、パルプ１０重量％としスラリーを調整する。その他は実施例１で使用したものと同様にして、無機質板を製造する。
【００１９】
この様にして得られた各種の無機質板（実施例１〜４、比較例１〜３）について、表面性状、生産性、耐凍結融解性を確認した。それらの結果を表１に示す。なお、表面性状は外観評価および平米あたりのピンホール数、生産性は一枚を製造する際の生産タクト(sec)、耐凍結融解性はJIS A 1435に準拠して200サイクル経過後の表面の外観観察、につき各々測定した。
【表１】

【００２０】
表１から明らかなように、実施例１の如くして得られた無機質板は表面が緻密でかつ素穴のないエンボス柄模様が付与される。また、基層は嵩高くなることにより脱水孔が増えるので、濾水性を向上させることができ生産性よく無機質板を製造することができる。また基層は脱水不良を生じることがないので基層マットにある程度の保型性があり、基層マット上に散布した表層原料は基層にめり込んでしまうことがなく、均一厚さに表層を散布積層することができるので、表面性が良好な無機質板を製造することができる。また、実施例２〜４では、基層がさらに嵩高くなることにより、表面性や生産性がより向上した無機質板を得ることができる。
【００２１】
【発明の効果】
したがって本発明によれば、基層を構成する原料は嵩高くなるために圧締する際の圧力が高くなり、あいともなって表層に高い圧締圧力が均一に及び、またエンボス模様を押圧成形する際、エンボス模様のある型板の凹部に原料が移動しやすくなるために、表層材料が緻密になり素穴のない無機質板となる。また、基層原料は嵩高くなるため混合時に分散されやすく均一なスラリーとなるので、型枠内に流下したスラリーは均一な厚みに流下され、表面性が良好な無機質板を製造することができる。また、基層は嵩高くなることで脱水孔が増加したポーラスな材料となるので、濾水性が良くなり生産性を向上させることができる。また、基層は脱水不良を生じることがないので確実に保型性のあるマットが表層散布前に形成され、よって基層マット上に散布した表層原料は基層にめり込んでしまうことがなく、ピンホール状の素穴のない表面性の良好な無機質板を製造することができる。
【図面の簡単な説明】
【図１】（A）従来の無機質板の押圧脱水成型前のマット断面図。
（B）本発明の無機質板の押圧脱水成型前のマット断面図。
【図２】本発明に係わる無機質板の製造設備を示す側面図。
【図３】従来の製品斜視図。
【符号の説明】
２基層スラリー流込装置
３表層粉体散布装置
４押圧脱水成型装置
５透水性シート
６洗浄装置
７廃水貯留受け
８吸引脱水装置
９搬送ベルト
１０型枠
１１基層マット
１２表層粉体原料
２１基層スラリー貯留槽
２２表層粉体混合物貯留槽
５１プレス
５２上盤
５３型板
５４下盤[0001]
[Technical field to which the invention belongs]
The present invention relates to an inorganic plate used for building materials such as outer wall materials and roofing materials, and a method for producing the same.
[0002]
[Prior art]
This type of inorganic board is a mat-like material in which a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber substance such as pulp is dispersed in water to form a slurry, and then the raw material mixture is allowed to flow down on a water-permeable sheet. And after dehydration molding with a press machine, it is cured by curing and dried. These inorganic plates are manufactured by integrally molding an uncured mat with a pressing device to form a flat flat plate without a pattern or sometimes an uncured plate having a real part. In addition to this method, an embossed pattern is imparted to the surface of the inorganic plate to give a three-dimensional change. In order to give this embossed pattern, the embossed pattern can be integrated with the pressure dehydration by using a press machine with a template with a pattern formed on the surface when the mat is pressed and dehydrated. In general, a method of forming a pattern is generally performed, and various patterns are imparted to an inorganic board.
[0003]
Recently, in order to obtain a deep embossed pattern on the surface of an inorganic board, a slurry in which a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber material such as pulp is dispersed in water is placed on the water-permeable sheet. There is provided a multi-layer type inorganic plate that is sprayed in a layered form, and further a raw material mixture of another composition is sprayed in a layered form on the upper surface and then press-molded. As a method for obtaining such a deep embossed pattern, the surface layer raw material has a moisture content of 40% or less, and a powder raw material blended with a lightweight aggregate in a specific range ratio is sprayed and laminated and pressed to form a deep surface. An embossed pattern is applied. (Japanese Patent Laid-Open No. 61-149312)
In addition, in order to make the product surface smooth and dense, the surface layer part is made dense by spraying powder cement with a small particle diameter and then pressing the powder material onto the surface layer material. The method to take is taken. (Japanese Patent Laid-Open No. 6-190818)
[0004]
[Problems to be solved by the invention]
However, according to the conventional example described above, an embossed pattern with a certain depth can be applied to the surface of an uncured inorganic base material using a press, but the raw material used for the surface layer has low moisture content and lacks fluidity. Therefore, especially when it is molded with a press machine with a template with a patterned pattern formed on the surface, the concave portion of the embossed pattern template corresponding to the portion constituting the convex portion of the inorganic plate at the time of pressing. The raw material is difficult to move, and a porous portion is likely to be generated on the surface. As a result, pinholes, so-called bare holes, are often generated on the surface of the porous portion, and the surface properties of the inorganic plate become insufficient due to the bare holes. Assuming the case of using the inorganic board on the outer wall member, this to become like tends to occur water due to rainfall from Motoana, there is a problem such adverse effects on the penetration resistance water performance of inorganic electrolyte plate. This bare hole not only reduced the surface density and design, but also increased the water permeability, which significantly deteriorated the durability of the product, such as generation of cracks due to expansion and contraction of water absorption drying and deterioration of freeze-thaw performance.
[0005]
Also, when forming the base layer by flowing the slurry into the mold placed on the water-permeable sheet, if the raw materials are not evenly mixed, scattering unevenness is likely to occur in the plate, and it is spread thinner than usual. Since the spot becomes porous, pinhole-shaped blanks are easily generated on the surface after press molding. In addition, the base layer material that is a paste-like slurry is matted so that it can be dehydrated to some extent before spraying the surface layer raw material, but if this base layer material is insufficiently dehydrated, Since the mat is in a soft state, when the surface layer raw material is sprayed, the surface layer raw material enters the base layer raw material, and a reverse phenomenon occurs in which the base layer raw material with a high water content is indexed to the surface layer surface. Only the part is poorly dehydrated and pinhole-shaped holes are likely to occur.
[0006]
In order to eliminate this phenomenon, the surface powder raw material contains a large amount of moisture to improve the fluidity at the time of press molding, but when the powder raw material is mixed with excess moisture, There is a problem that the reinforcing fiber material easily aggregates in a ball shape, and it takes time for dehydration during molding to deteriorate productivity, and if the dehydration is insufficient, the surface property of the portion is lowered. Furthermore, although measures are taken to improve the water permeability by painting the surface of the inorganic board, a certain amount of coating is required to completely hide the bare holes, so that the water permeability of the original board is improved. Had the problem of increasing the cost of painting.
In addition, in order to make the product surface dense, means to further spread the powder material on the surface layer raw material is taken, but since the raw material with a small particle diameter is sprayed on the surface layer, it is fine on the surface of the template after molding. The powder material tends to adhere and the surface quality of the molded product is deteriorated, and new equipment is required to spray raw materials with small particle diameters, making the manufacturing equipment large and the manufacturing cost It had a problem such as raising. In other words, there is no need for excessive coating so far, and without causing an increase in production cost, the surface of the inorganic plate is smooth and dense without any holes, and in particular, improving the water resistance of the inorganic plate is its performance. It was an important issue. The present invention has been made in order to solve the above-mentioned problems. In an inorganic plate obtained by spraying a surface layer raw material on the surface of a base layer mat and subjected to press dehydration molding and a method for producing the same, an inorganic material can be used without excessive coating. It aims at providing the inorganic board which improves the surface property of board products, and improves productivity, and its manufacturing method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in claim 1, a slurry mainly composed of cement and a reinforcing fiber substance is flowed into a mold placed on a water permeable sheet and then dehydrated to form a base layer. An inorganic plate obtained by spreading and laminating a powder mixture mainly composed of cement and reinforcing fiber material on the upper surface of the base layer, and curing and curing after dehydration molding, the base layer having a lightweight aggregate; The present invention provides an inorganic board obtained by forming a slurry containing an inorganic board recycled raw material and a reinforcing fiber substance, and spraying and laminating a powder mixture mainly composed of cement and the reinforcing fiber substance on the upper surface of the base layer. According to the above configuration, the slurry containing the lightweight aggregate, the inorganic board recycling raw material, and the reinforcing fiber substance becomes bulky, so that the pressure during pressing increases, and the high pressing pressure uniformly reaches the surface layer. In addition, when the embossed pattern is press-molded, the raw material easily moves to the concave portion of the template having the embossed pattern formed on the surface, so that the surface layer material becomes dense and becomes an inorganic plate without a hole. Further, since the base layer raw material is bulky, it is easily dispersed during mixing and becomes a uniform slurry, so that the slurry flowing into the mold has no thickness unevenness. In addition, since the base layer becomes bulky and becomes a porous slurry with increased dewatering holes, the productivity is improved, and the base layer surely becomes a mat having a shape-retaining property, so that the base layer is spread on the base layer mat. The surface layer raw material is not sunk into the base layer, and the surface of the inorganic plate after the press dehydration molding is free from pinhole-shaped blanks.
[0008]
According to the second aspect of the present invention, a slurry mainly composed of cement and a reinforcing fiber material is poured into a mold placed on a water-permeable sheet and then dehydrated to form a base layer, and a cement layer is formed on the upper surface of the base layer. Is a method of manufacturing an inorganic board in which a powder mixture mainly composed of a reinforcing fiber material is dispersed and laminated, and cured and cured after dehydration molding, wherein the base layer includes a lightweight aggregate, an inorganic board recycled raw material, a reinforcing fiber substance, A slurry containing selenium is flowed into a mold, and a powder mixture mainly composed of cement and reinforcing fiber material is sprayed and laminated on the upper surface of the slurry. is there. According to the above configuration, since the raw material constituting the base layer is bulky, the pressure during pressing is high, and since the high pressing pressure is uniformly applied to the surface layer, the embossed pattern is pressed. Since the raw material easily moves to the concave portion of the embossed template, it is possible to easily manufacture an inorganic plate having a dense surface layer material and having no holes. Further, since the base layer raw material is bulky, it is easily dispersed during mixing and becomes a uniform slurry. Therefore, the slurry that has flowed into the mold can flow down to a uniform thickness. Further, since the base layer becomes bulky, dewatering pores increase, so that the drainage can be improved and the inorganic board can be produced with good productivity. The surface layer material spread on the base layer does not sink into the base layer, and the surface layer can be reliably sprayed and laminated with a uniform thickness, so that an inorganic plate with good surface properties can be produced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention are described in detail below.
The inorganic board according to the present invention is composed of a base layer and a surface layer, and a slurry in which a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber material such as pulp is dispersed in water is layered on a water-permeable sheet. The base material is a mat that flows down and dehydrated, and on the top surface is a raw material obtained by spraying a mixture of powder raw materials, which are mainly composed of hydraulic materials such as cement and reinforcing fiber materials such as pulp, in layers. And an inorganic plate obtained by press dehydration molding. Here, examples of the hydraulic material include Portland cement, blast furnace slag cement, silica cement, fly ash cement, and alumina cement. Further, as the reinforcing fiber material, for example, wood pieces, wood pulp, wood fiber bundles, wood hair, wood powder, synthetic fibers, etc. are used, polyester fiber, polyamide fiber, acrylic fiber, polyvinylidene chloride fiber, acetate fiber, etc. Organic fibers, or inorganic fibers such as sepiolite, wollastonite and glass fibers may be used.
[0010]
Further, in the present invention, in addition to the above components, for example, inorganic fillers such as silica sand, silica stone powder, silica fume, blast furnace slag, fly ash, shirasu balloon, perlite, bentonite, diatomaceous earth, and the like, calcium chloride, Anhydrous or crystallized chlorides such as magnesium chloride, iron chloride, aluminum chloride, sodium chloride, potassium chloride, lithium chloride, sulfuric acid such as aluminum sulfate, alum, iron sulfate, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate Salt anhydrous or crystallized, nitrates such as calcium nitrate and calcium nitrite, inorganic or crystallized nitrite, formate such as calcium formate and calcium acetate, anhydrous or crystallized acetate, sodium aluminate, water Cement hardening accelerator such as glass and wax, Paraffin, water repellent agents such as silicon, expandable thermoplastic plastic beads such as foamed polystyrene beads may be added.
[0011]
In order to produce the inorganic board of the present invention, the mixture of the above raw materials is dispersed in water to form a slurry, the slurry is supplied onto the water-permeable sheet, sucked and dehydrated from the back of the sheet, the mat is formed, and the upper surface thereof A method is adopted in which powder raw materials are sprayed in layers, subjected to pressure dehydration molding, and then cured and cured. Of the inorganic hardened layer, a cement and a silicate-containing substance are desirably used as a raw material for the base layer, and the total amount of the cement and the silicate-containing substance is 60 to 95% by weight in the base layer raw material. The ratio of the cements to the silicic acid-containing substance is usually 70:30 to 30:70 by weight. The reinforcing fiber material to be dispersed in the base layer raw material is usually added in an amount of 5 to 15% by weight in the raw material, and when synthetic fibers are added, it is usually added in an amount of 5% by weight or less in the raw material. The silicic acid-containing substance smoothly and completely cures the inorganic board by the reaction between cement and calcium silicate, and the resulting product has good dimensional stability.
[0012]
Furthermore, in the present invention, light aggregate, inorganic board recycled raw material, and raw material with low bulk specific gravity of the reinforcing fiber substance are contained to produce a bulky slurry. When lightweight aggregate is added, the lightweight aggregate is usually used in an amount of 1 to 15% by weight in the raw material, and when adding an inorganic board recycled raw material, an amount of 1 to 20% by weight is usually used in the raw material. Is desirable. These raw materials reduce the weight of the inorganic board to be produced and make the slurry bulky, so they are essential components for the present invention. However, when the content exceeds the required amount in the mixture, the specific gravity is reduced and the reinforcing fiber material is aggregated. As a result, the strength of the inorganic plate obtained tends to decrease.
[0013]
On the other hand, the surface layer of the inorganic hardened layer is a semi-dry powder raw material mixture to which some moisture is added, and is formed on the upper surface of the base layer. The surface layer is composed mainly of cement and a reinforcing fiber material as in the base layer, and preferably the cement and the silicic acid-containing material are used, and the total amount of the cement and the silicic acid-containing material is 60 to 95% by weight. %, And the ratio of the cements to the silicic acid-containing material is usually 70:30 to 30:70 by weight. Further, it is desirable to use 0 to 10% by weight of the reinforcing fiber material dispersed in the surface layer raw material and 0 to 7% by weight of the lightweight aggregate. Moreover, it is desirable that the base layer slurry is 70 to 95% of the total solid content and the surface layer powder raw material is 5 to 30% with respect to the spreading amount of the base layer and the surface layer.
[0014]
As shown in FIG. 2, the manufacturing equipment for the inorganic board according to the present invention includes a base layer slurry casting device 2, a surface powder spraying device 3, a press dehydration molding device 4, a movable water permeable sheet 5, a suction dehydration device 8, It consists of a conveyor belt 9 and the like.
That is, the base layer slurry casting apparatus 2 includes a slurry storage tank 21, the surface powder dispersion apparatus 3 includes a powder mixture storage tank 22, and the suction dehydration apparatus 8 includes a suction machine. Yes. On the other hand, the press dewatering device 4 has a press 51, and the press 51 includes an upper board 52 and a lower board 54. Here, the lower board 54 is provided with a suction dehydrating device and is fixed to the main body of the press 51, whereas the upper board 52 is fixed with an embossing template 53 having a pattern pattern formed on the surface thereof, which can be driven up and down. It is supported by. A water permeable sheet 5 is rotatably stretched in such a manner that the slurry pouring device 2, the surface powder spraying device 3, the press dehydration molding device 4, and the suction dehydration device 8 are sequentially connected. A belt 9 for transportation is stretched around the belt so as to be rotatable.
[0015]
The base layer raw material is usually mixed with water so as to have a water content of 300 to 400% to form a slurry. A predetermined amount of the kneaded slurry is poured into a mold 10 placed on a mesh-like water-permeable sheet 5 and supplied, and after the slurry is leveled, the suction device of the suction dehydrator 8 from the back surface of the water-permeable sheet. To dehydrate from the lower surface of the slurry. After dehydration, the moisture content of the slurry is reduced to a moisture content that allows the mold to be retained, and a flat mat 11 having a moisture content of 150 to 200% is usually formed in the mold. Then, the water-permeable sheet 5 is rotated and transferred to the vicinity of the surface layer material spraying device 3, and the powder material 12 is uniformly sprayed on the base layer mat. Here, it is desirable that the dispersion rate of the powder raw material is 5 to 30% by weight with respect to the solid content of the base material.
After spraying the surface layer, the mold 10 is removed to leave only the mat on the water permeable sheet, the water permeable sheet 5 is rotated and moved to the vicinity of the pressure dehydration molding device 4, and then the top of the pressure dehydration molding device. While being positioned between the board 52 and the lower board 54, the upper board is lowered by a predetermined stroke. By pressing with such a pressure dewatering molding device, it is dewatered and molded into a plate shape. If desired, a pattern is applied to the mat surface by a template 53 fixed to the upper board.
The inorganic board manufactured in this way moves to a curing process and is cured, but is cut out to a predetermined size before or after curing. Curing is a two-step curing method in which the mat is left to stand in an enclosed room for 6 to 30 hours without heating or under normal pressure, followed by primary curing, followed by normal curing at 160 to 180 ° C. for 6 to 15 hours to complete curing. Is used. After curing and curing, the mat cured product is trimmed, painted, etc., if desired, to obtain an inorganic board product.
[0016]
【Example】
Examples of the present invention will be described below.
Example 1
A raw material mixture having the following composition is prepared as a raw material for the base layer.
Portland cement 40% by weight, quartzite powder 39% by weight, pearlite 6.7% by weight, inorganic board recycling raw material 6.7% by weight, pulp 6.7% by weight, synthetic fiber 1% by weight, the above raw material mixture is mixed with water Then, the slurry is adjusted to a water content of 300% by uniform stirring. The raw material slurry is poured into a mold placed on a water-permeable sheet, leveled, and dehydrated for a certain period of time with a suction dehydrator installed on the bottom surface of the water-permeable sheet so that the water content of the slurry is 150%.
[0017]
On the other hand, a raw material mixture having the following composition is prepared as a raw material for the surface layer.
Portland cement 42% by weight, quartzite powder 42% by weight, pearlite 7% by weight, inorganic board recycled raw material 5% by weight, pulp 3% by weight, synthetic fiber 1% by weight, water is added so that the water content is 20% To obtain a powder raw material.
And this powder raw material is spread | dispersed on a base layer by 25% with respect to the total solid, and this is pressure-dehydration-molded with the press apparatus which attached the template which formed the pattern pattern on the surface so that it might become set thickness . The mat thus formed is subjected to primary curing at 60 to 80 ° C. for 6 to 30 hours and secondary curing at 160 to 180 ° C. for 6 to 15 hours in an autoclave to obtain a predetermined inorganic plate.
[0018]
Example 2
The composition of the base layer raw material is adjusted as follows.
A slurry is prepared with 35% by weight of Portland cement, 34% by weight of quartzite powder, 10% by weight of pearlite, 10% by weight of recycled inorganic board, 10% by weight of pulp, and 1% by weight of synthetic fiber. The other conditions are the same as those used in Example 1 to produce an inorganic board.
Example 3
The composition of the base layer raw material is adjusted as follows.
A slurry is prepared with 35% by weight of Portland cement, 34% by weight of quartzite powder, 5% by weight of pearlite, 15% by weight of recycled inorganic board, 10% by weight of pulp, and 1% by weight of synthetic fiber. Otherwise, the inorganic plate is produced in the same manner as in Example 1.
Example 4
The composition of the base layer raw material is adjusted as follows.
A slurry is prepared with 35% by weight of Portland cement, 34% by weight of quartzite powder, 10% by weight of pearlite, 5% by weight of recycled inorganic board, 15% by weight of pulp, and 1% by weight of synthetic fiber. Otherwise, the inorganic plate is produced in the same manner as in Example 1.
Comparative Example 1
A raw material mixture having the following composition is prepared as a raw material for the base layer.
The slurry is prepared with 40% by weight of Portland cement, 39% by weight of quartzite powder, 10% by weight of inorganic board recycling raw material, 10% by weight of pulp, and 1% by weight of synthetic fiber. Otherwise, the inorganic plate is produced in the same manner as in Example 1.
Comparative Example 2
A raw material mixture having the following composition is prepared as a raw material for the base layer.
The slurry is prepared with 40% by weight of Portland cement, 39% by weight of quartzite powder, 10% by weight of pearlite, 10% by weight of pulp, and 1% by weight of synthetic fiber. Otherwise, the inorganic plate is produced in the same manner as in Example 1.
Comparative Example 3
A raw material mixture having the following composition is prepared as a raw material for the base layer.
The slurry is adjusted to 40% by weight of Portland cement, 39% by weight of quartzite powder, 5.5% by weight of pearlite, 5.5% by weight of recycled inorganic board, and 10% by weight of pulp. Otherwise, the inorganic plate is produced in the same manner as in Example 1.
[0019]
The surface properties, productivity, and freeze-thaw resistance were confirmed for the various inorganic plates (Examples 1 to 4 and Comparative Examples 1 to 3) thus obtained. The results are shown in Table 1. The surface texture is the appearance evaluation and the number of pinholes per square meter, the productivity is the production tact (sec) when manufacturing one sheet, and the freeze-thaw resistance is JIS A 1435 according to JIS A 1435. Each appearance was measured.
[Table 1]

[0020]
As is apparent from Table 1, the inorganic board obtained as in Example 1 has a fine surface and an embossed pattern with no open holes. In addition, since the base layer becomes bulky and dewatering pores increase, the drainage can be improved and an inorganic plate can be produced with high productivity. In addition, since the base layer does not cause dehydration failure, the base layer mat has a certain degree of shape retention, and the surface layer material spread on the base layer mat does not sink into the base layer, and the surface layer is spread and laminated to a uniform thickness. Therefore, an inorganic plate having a good surface property can be produced. Moreover, in Examples 2-4, when the base layer becomes further bulky, an inorganic plate with improved surface properties and productivity can be obtained.
[0021]
【The invention's effect】
Therefore, according to the present invention, since the raw material constituting the base layer is bulky, the pressure during pressing is high, and the high pressing pressure is uniformly applied to the surface layer and when the embossed pattern is pressed. Since the raw material easily moves to the concave portion of the embossed template, the surface layer material becomes dense and becomes an inorganic plate having no bare holes. In addition, since the base layer raw material becomes bulky and is easily dispersed during mixing, it becomes a uniform slurry. Therefore, the slurry that has flowed down into the mold can flow down to a uniform thickness, and an inorganic plate with good surface properties can be manufactured. Moreover, since the base layer becomes bulky and becomes a porous material having increased dewatering pores, the drainage is improved and the productivity can be improved. In addition, since the base layer does not cause dehydration failure, a mat with a shape-retaining property is surely formed before the surface layer is sprayed, so that the surface layer material sprayed on the base layer mat does not sink into the base layer and is pinhole-like. It is possible to produce an inorganic plate having a good surface property without any bare holes.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view of a mat before press dehydration molding of a conventional inorganic plate.
(B) The cross-sectional view of the mat before press dehydration molding of the inorganic plate of the present invention.
FIG. 2 is a side view showing equipment for manufacturing an inorganic plate according to the present invention.
FIG. 3 is a perspective view of a conventional product.
[Explanation of symbols]
2 Base Layer Slurry Casting Device 3 Surface Layer Powder Dispersing Device 4 Pressing Dehydration Molding Device 5 Permeable Sheet 6 Washing Device 7 Waste Water Storage Receiver 8 Suction Dehydration Device 9 Conveying Belt 10 Mold 11 Base Layer Mat 12 Surface Layer Powder Raw Material 21 Base Layer Slurry Storage Tank 22 Surface powder mixture storage tank 51 Press 52 Upper board 53 Template 54 Lower board

Claims

A slurry containing cement, a silicate-containing material, a reinforcing fiber material, a lightweight aggregate, and an inorganic board recycling raw material is poured into a mold placed on a water-permeable sheet and then dehydrated to form a base layer. A powder mixture containing cement, a silicic acid-containing substance, a reinforcing fiber substance, a lightweight aggregate, and an inorganic board recycling raw material is spread and laminated on the upper surface of the base layer , and cured and cured after dehydration molding. An inorganic board obtained by
The composition of the slurry to be the base layer is that the total amount of cement and silicic acid-containing material is 60 to 95% by weight, the light aggregate is 1 to 15% by weight, and the inorganic board recycling raw material is 1 with respect to the base layer raw material. ~ 20 wt% , reinforcing fiber material is 5-15 wt%,
The composition of the powder mixture used as the surface layer is such that the total amount of cement and silicic acid-containing material is 60 to 95% by weight, the reinforcing fiber material is 10% by weight or less, and the lightweight aggregate is 7% with respect to the surface layer raw material. % By weight or less,
The amount of the slurry as the base layer and the powder mixture as the surface layer is 70 to 95% by weight of the slurry and 5 to 30% by weight of the powder mixture, based on the total solid content,
The total amount of the reinforcing fiber substance, the lightweight aggregate, and the inorganic board recycling raw material in the slurry that becomes the base layer is larger than in the powder mixture that becomes the surface layer,
Furthermore, the total amount of the lightweight aggregate in the slurry as the base layer and the inorganic board recycling raw material is larger than in the powder mixture as the surface layer.
An inorganic board characterized by that .

A slurry containing cement, a silicate-containing material, a reinforcing fiber material , a lightweight aggregate, and an inorganic board recycling raw material is poured into a mold placed on a water-permeable sheet and then dehydrated to form a base layer. Forming and spraying and laminating a powder mixture containing cement , silicic acid-containing material, reinforcing fiber material , lightweight aggregate, and inorganic board recycling raw material on the upper surface of the base layer , and curing and curing after dehydration molding A method for producing an inorganic board,
The composition of the slurry used as the base layer is 60 to 95% by weight of the total amount of cement and silicic acid-containing material , 1 to 15% by weight of lightweight aggregate, and 1 to 20 % of the inorganic board recycled raw material . % By weight, 5 to 15% by weight of reinforcing fiber material ,
The composition of the powder mixture as the surface layer is such that the total amount of cement and silicic acid-containing material is 60 to 95% by weight, the reinforcing fiber material is 10% by weight or less, and the lightweight aggregate is 7% by weight with respect to the surface layer raw material. And
Each amount of the slurry as the base layer and the powder mixture as the surface layer is 70 to 95% by weight of the slurry and 5 to 30% by weight of the powder mixture with respect to the total solid content.
The total amount of the reinforcing fiber substance, the lightweight aggregate, and the inorganic board recycling raw material in the slurry that becomes the base layer is larger than that in the powder mixture that becomes the surface layer,
Furthermore, the manufacturing method of the inorganic board characterized by making the total amount of the lightweight aggregate and the inorganic board recycling raw material in the slurry used as the base layer larger than in the powder mixture used as the surface layer .