JP4180861B2

JP4180861B2 - Wood cement board and manufacturing method thereof

Info

Publication number: JP4180861B2
Application number: JP2002252226A
Authority: JP
Inventors: 文宏朝倉
Original assignee: Nichiha Corp
Current assignee: Nichiha Corp
Priority date: 2002-08-30
Filing date: 2002-08-30
Publication date: 2008-11-12
Anticipated expiration: 2022-08-30
Also published as: JP2004091230A

Description

【０００１】
【発明の属する技術分野】
本発明は外壁材等の建築板に好適な木質セメント板、特に木片セメント板およびその製造方法に関するものである。
【０００２】
【従来の技術】
従来、木質セメント板における火災時の防火性能に関しては様々な手法が検討されている。
火災などの燃焼条件下において構造内部に火が回らないような工夫が必要であり、そのためには燃焼時の基材収縮が少ない基材が必要である。
代表的な手法としては石綿を添加する方法があるが、石綿は発ガン性物質の一つであり、石綿微粉末の飛散によって環境汚染が問題となり、取り扱いが困難である。
また、燃焼時の基材収縮を抑制するために、マイカを添加することが従来から行われている。（例えば特許第２７５４３０６号）
さらに、防火性能の向上のために水酸化マグネシウムや水酸化アルミニウムを添加することが行われ、マイカと組み合わせて添加することも行われている。（例えば特開平６−３４５５０８）
【０００３】
【発明が解決しようとする課題】
しかしながら、特開平６−３４５５０８は湿式による製造方法で、しかも木質補強材はパルプであり、セメントの硬化阻害性などを考える必要がなく、木質補強材として木片を使用した、いわゆる木片セメント板での耐火性、不燃性、防火性は十分には研究されていなかった。
【０００４】
【課題を解決するための手段】
上記課題を解決するために、本発明は、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料とした緻密構造の表層または表裏層と、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料とした粗構造を有する芯層とを有する木質セメント板であることを特徴としている。
上記構成によれば、防火耐火性能に優れた木質セメント板を提供することが出来る。
【０００５】
また、本発明は、前記水酸化物が水酸化アルミニウムであることを特徴としている。
上記構成によれば、防火耐火性能に優れた木質セメント板を提供することが出来る。
【０００６】
また、本発明は、前記マイカは全原料に対して１５質量％以上２５質量％以下添加されていることを特徴としている。上記構成によれば、強度低下を起こさず、しかも、防火耐火性能に優れた木質セメント板を提供することが出来る。
【０００７】
また、本発明は、前記水酸化物は全原料に対して１０質量％以上２０質量％以下添加されていることを特徴としている。
上記構成によれば、強度低下を起こさず、しかも、防火耐火性能に優れた木質セメント板を提供することが出来る。
【０００８】
また、本発明は、前記表層または表裏層の木質補強材は木粉または／および木片で、芯層の木質補強材は木片または／および木質繊維束であることを特徴としている。
上記構成によれば、硬化阻害物質の多い木片等を使用しても強度低下を起こさず、防火耐火性能に優れた木質セメント板を提供することが出来る。
【０００９】
また、本発明に係る木質セメント板の製造方法としては、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した表裏層用原料混合物を型板上に散布して表層とし、その上にセメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した芯層用原料混合物を散布積層して芯層とし、さらにその上にセメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した表裏層用原料混合物を散布して裏層として三層構造とするか、または、裏層を成形しないで二層構造とした積層物を圧締して水分存在下でオ−トクレ−ブ硬化養生することを特徴としている。
上記構成によれば、防火耐火性能に優れた木質セメント板を製造することが出来る。
【００１０】
また、本発明は、前記表裏層用原料混合物および芯層用原料混合物を準備する際、木質補強材と水酸化物とを先に混合し、そのあと残りの原料を混合することを特徴としている。
上記構成によれば、木質補強材の表面に水酸化物がコーティングされた状態を準備することが出来、その結果、木質補強材からのセメント硬化阻害物質の発生を抑えることが出来、強度低下を起こさず、防火耐火性能が向上する。
【００１１】
【発明の実施の形態】
以下、本発明の実施の形態を具体的に説明する。
〔セメント系無機材料〕
本発明に用いられるセメント系無機材料としては、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、白色セメント等のセメント類がある。
上記セメント類は二種以上混合使用されてもよい。
【００１２】
〔ケイ酸含有物質〕
本発明に用いられるケイ酸含有物質としては、ケイ砂、ケイ石粉、シリカ粉、シリカフュ−ム、フライアッシュ、高炉スラグ、シラスバル−ン、パ−ライト、珪藻土、ドロマイト等のケイ酸含有物質がある。
上記ケイ酸含有物質は二種以上混合使用されてもよい。
【００１３】
〔木質補強材〕
本発明に用いられる木質補強材としては、木粉、木毛、木片、木質繊維、木質パルプ、木質繊維束、ドライパルプ、ケナフ、竹繊維、麻繊維、バカス、もみがら、稲わら等が使用される。
表層または表裏層には細かめの木質補強材を使用することが好ましく、例えば、木粉や木片を使用することが好ましく、特に好ましいのは２０〜５０メッシュの木粉や、幅０．５〜２．０ｍｍ、長さ１．０〜１０．０ｍｍ、アスペクト比（長さ／厚み）２０〜３０の木片である。
表層または表裏層に細かめの木質補強材を使用することで、表層または表裏層の密度が緻密になり防火性向上に寄与する。
芯層には粗めの木質補強材を使用することが好ましく、例えば、木片や木質繊維束を使用することが好ましく、特に好ましいのは幅０．５〜３．０ｍｍ、長さ１．０〜２０ｍｍ、アスペクト比（長さ／厚み）２０〜３０の木片や、径０．１〜２．０ｍｍ、長さ２．０〜３５．０ｍｍの分枝および／または彎曲および／または折曲した木質繊維束である。
芯層に粗めの木質補強材を使用することで、木質セメント板にクッション性が付与され、表面に凹凸模様を付した場合に極めて鮮明で深い凹凸模様が形成出来る。
前記木質補強材は二種以上混合されてもよい。
また、木質補強材として木質スクラップから再生したものを使用することも出来る。
【００１４】
［マイカ］
本発明に用いられるマイカとしては、平均粒径１５０μｍ以上、アスペクト比６５以上のフレ−ク状のものであり、特に平均粒径３４０μｍ以上、アスペクト比８０以上のものが好ましい。
平均粒径１５０μｍ未満では、粒径が細かいので、マイカ相互の接着面積が小さく、十分な基材収縮抑制による寸法安定性を得られにくい。
マイカは、通常層状構造を有し、吸湿性がなく、剛性を有する高弾性体であり、木質補強材を含む木質セメント板の寸法安定性を大幅に向上させることが出来る。
【００１５】
［水酸化物］
本発明に用いられる水酸化物としては、水酸化アルミニウム、水酸化マグネシウム、水酸化亜鉛等があるが、水酸化アルミニウムは２００〜３００℃付近の高熱下で酸化アルミニウムと水に分解反応を起こし、この反応が吸熱反応なので、燃焼熱を緩和し板内の他の物質（木片など）への熱の影響を遅らせる効果があり、そのため防火耐火性能が向上するので、特に好ましい。
【００１６】
〔第三成分〕
本発明の木質セメント板の原料としては、上記以外の成分として、木質セメント板の廃材粉砕物や、ベントナイト、バ−ミキュライト等の鉱物粉末や、ロウ、ワックス、パラフィン、シリコン、界面活性剤等の防水剤、撥水剤や、発泡性熱可塑性プラスチックビ−ズ、プラスチック発泡体等や、塩化カルシウム、塩化マグネシウム、硫酸カリウム、硫酸カルシウム、硫酸マグネシウム、硫酸アルミニウム、アルミン酸ナトリウム、アルミン酸カリウム、蟻酸カルシウム、酢酸カルシウム、アクリル酸カルシウム、水ガラス等のセメント硬化促進剤が添加されてもよい。
【００１７】
〔木質セメント板の組成〕
本発明の木質セメント板の表裏層の原料混合物は、セメント系無機材料３０質量％以上６０質量％以下、ケイ酸含有物質１０質量％以上３０質量％以下、木粉または／および木片５質量％以上１５質量％以下、マイカ１５質量％以上２５質量％以下、水酸化物１０質量％以上２０質量％以下を含有することが好ましく、更に芯層の原料混合物はセメント系無機材料３０質量％以上６０質量％以下、ケイ酸含有物質１０質量％以上３０質量％以下、木片または／および木質繊維束５質量％以上１５質量％以下、マイカ１５質量％以上２５質量％以下、水酸化物１０質量％以上２０質量％以下を含有することが好ましい。
マイカが１５質量％未満であると、木片セメント板としての寸法安定性が得られにくく、２５質量％より多いとマイカは平板積層状であるので、バインダ−分であるセメント系無機材料、ケイ酸含有物質が他のマトリックスと結合しにくくなり原料の均一な混合分散がおこなわれず、防火耐火性能、強度が低下する。
また、表裏層に添加するマイカと芯層に添加するマイカの添加比率は、表裏層と芯層との基材収縮の差がなくなるので同じ位の添加比率がよい。
水酸化物が１０質量％未満であると、防火耐火性能の向上はさほど得られず、２０質量％より多くても、飛躍的に防火耐火性能のは向上せず、逆にコストアップとなる。
木質補強材が５質量％未満であると、補強効果があらわれず、１５質量％よりも多いと、防火性を保持できない。
【００１８】
〔木質セメント板の製造方法〕
本発明の木質セメント板の製造方法としては、乾式又は半乾式製造方法が好ましい。
半乾式製造方法においては、まず、上記のセメント系無機材料、ケイ酸含有物質、木質補強材、マイカ、水酸化物を含有する原料混合物に所定量の水分を添加混合し表裏層用原料混合物とした後、型板上に散布して表層とし、その上にセメント系無機材料、ケイ酸含有物質、木質補強材、マイカ、水酸化物を含有する原料混合物に所定の水分を添加混合した芯層用原料混合物を散布積層して芯層とし、さらにその上に表裏層用原料混合物を散布積層して裏層として三層構造とするか、または、裏層を成形しないで二層構造とした積層物マットをフォ−ミングする。
ここで型板とは、エンボス柄模様を形成したもの、搬送板的なもの等、散布する原料を受け取りマットが形成される支持板であれば特に限定されない。
木質補強材としては、表裏層は木粉または／および木片を、芯層は木片または／および木質繊維束を添加することが好ましい。
乾式製造方法においては、上記の原料混合物を水分を添加することなく型板上に散布し積層物マットを形成し、このマットに所定量の水を添加する。
この表裏層用原料混合物および芯層用原料混合物を準備する際、木質補強材と水酸化物とを先に混合し、そのあと残りの原料を混合することが好ましい。
特に木質補強材が木片の場合には木片の表面の周りを水酸化物がコ−ティングした状態になり、そのため木片への熱の影響を遮る効果があり、加熱加水中で木片より発生するセメント硬化阻害物質が発生しにくく、その為、セメント硬化阻害物質が発生する前にセメントの硬化が進行するので、強度低下を起こさない。上記原料混合物を型板上に散布する場合、複数枚の型板をコンベア上に並べて型板を搬送しつつ原料混合物を逐次型板上に散布し、この際型板搬送方向と逆方向に向けて風を吹き付けて風選をおこなうと、原料混合物中の微細成分が型板側（表面側）に多く配分され、粗大成分が型板反対側（裏面側）に多く配分され、緻密表面が得られる。
また、この風選の際、マイカがマットの厚み方向に配向しやすいので、そのために、マットの中でマイカが厚み方向に積層した状態となり、基材収縮抑制による寸法安定性に優れるとともに、熱の伝導も抑制することができるので、防火性能にも寄与する。
そしてフォ−ミングした積層マットを、２〜５ＭＰａの圧力で圧締して、６０〜８０℃、８〜１２時間の条件で一次硬化せしめ、更に１６０℃以上、望ましくは０．５ＭＰａ以上の圧力でオ−トクレ−ブ養生を行う。
上記の木質セメント板の製造工程においては、１６０℃以上の温度、望ましくは０．５ＭＰａ以上の圧力下のオ−トクレ−ブ養生によって、マイカ表面からケイ酸質成分やアルミナ成分が多少溶出し、そのためにマイカ表面が粗面になり、マイカ相互の重なり合い面積が大きくなる。
その為、マイカの重なり合い部分にセメント系無機材料から溶出したカルシウム分がマイカ相互の重なり部分の間に入り込みやすく、このカルシウム分がマイカ表面から溶出したケイ酸質成分と反応して安定したケイ酸カルシウム反応物が生成され、該反応物はマイカ相互を接着し、マイカ相互の大きな重なり合い面積、即ち接着面積と相剰してマイカ相互が強固に接合される。
その結果、本発明の木質セメント板は大きな機械的強度と大幅に改良された寸法安定性、防火耐火性能を獲得する。
【００１９】
【実施例】
以下、本発明の実施例を挙げる。
【００２０】
〔実施例１〜７〕
木質セメント板の原料として表１に示す組成の混合物を準備した。
表裏層の原料として、木質補強材としては、長径１．０〜１０．０ｍｍ、短径０．５〜２．０ｍｍ、アスペクト比２０〜３０、の木片を使用し、マイカは平均粒径３４０μｍ、アスペクト比８０のものを使用し、水酸化物としては水酸化アルミニウムを使用し、添加水は全固形分対比での外添、硬化剤はセメント対比での外添で水ガラスを使用した。
芯層の原料として、木質補強材としては長径１０〜２０ｍｍ、短径０．５〜３．０ｍｍ、アスペクト比２０〜３０、の木片と、直径０．１〜２．０ｍｍ、長さ２〜３５ｍｍの分枝および／または彎曲および／または折曲された木質繊維束を使用し、他の原料は表裏層の原料と同じものを使用した。
まず、表裏層の原料のうち、木片と水酸化アルミニウムとをアイリッヒミキサ−等の撹拌装置で撹拌混合した。
その後、表裏層の他の原料を混合して、表裏層用混合物とした。
これとは別に、芯層用の原料のうち、木片と木質繊維束と水酸化アルミニウムとを撹拌混合し、その後、芯層の他の原料を混合して芯層用混合物とした。
そして、複数枚の型板をコンベア上に並べて型板を搬送しつつ、この表裏層用原料混合物を逐次型板上に散布して表層とし、その上に芯層用原料混合物を散布積層して芯層とし、さらにその上に表裏層用原料混合物を散布積層して裏層として三層構造マットととした。
このフォ−ミングしたマットを、３ＭＰａの圧力で圧締して、７０℃、１０時間の条件で一次硬化せしめ、脱型後、更に１６５℃キ−プ時間７時間でオ−トクレ−ブ養生を行った。
【００２１】
〔比較例１〜４〕
表２に示す原料混合物で、実施例同様の条件で木質セメント板を製造した。
【００２２】
【表１】

【００２３】
【表２】

【００２４】
曲げ強度は、ＪＩＳＡ１４０８に準じた。
燃焼収縮は、燃焼試験（電気炉内で９００℃、１時間燃焼試験片７×２０ｃｍ）前後での試験片寸法にて収縮率を算出し、◎−良好、○−製品として問題にならない、△−製品として問題となる、×−不良の４段階で評価した。
燃焼時クラックは、燃焼試験後の試験片表面および小口のクラックの様子を目視観察し、◎−良好（クラックほとんどなし）、○−製品として問題にならない（クラック少）、△−製品として問題となる（クラック中）、×−不良（クラック多）の４段階にて評価した。
マイカを１５〜２５質量％、水酸化アルミニウムを１０〜２０質量％添加した実施例１〜７は、マイカの替わりに石綿を添加した比較例１（ブランク）と比較して、曲げ強度の低下もなく、燃焼収縮、燃焼時クラックも良好であった。
水酸化アルミニウムのみを添加した比較例２は、強度低下はおこさなかったが、燃焼収縮が不良で、燃焼時クラックも若干低下した。
マイカのみを添加した比較例３は強度低下はおこさなかったが、燃焼収縮が若干低下し、燃焼時クラックも若干低下した。
マイカ、水酸化アルミニウムをそれぞれ７質量％しか添加していない比較例４は、強度低下はおこさなかったが、燃焼収縮が低下し、燃焼時クラックも若干低下した。
【００２５】
以上説明したように、本発明によれば、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料とした緻密構造の表層または表裏層と、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料とした粗構造を有する芯層とを有する木質セメント板であるので、防火耐火性能に優れた木質セメント板を提供することが出来る。
【００２６】
また、本発明によれば、前記水酸化物が水酸化アルミニウムであるので、防火耐火性能に優れた木質セメント板を提供することが出来る。
【００２７】
また、本発明によれば、前記マイカは全原料に対して１５質量％以上２５質量％以下添加されているので、強度低下を起こさず、しかも、防火耐火性能に優れた木質セメント板を提供することが出来る。
【００２８】
また、本発明によれば、前記水酸化物は全原料に対して１０質量％以上２０質量％以下添加されているので、強度低下を起こさず、しかも、防火耐火性能に優れた木質セメント板を提供することが出来る。
【００２９】
また、本発明によれば、前記表層または表裏層の木質補強材は木粉または／および木片で、芯層の木質補強材は木片または／および木質繊維束であるので、硬化阻害物質の多い木片等を使用しても強度低下を起こさず、防火耐火性能に優れた木質セメント板を提供することが出来る。
【００３０】
また、本発明によれば、セメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した表裏層用原料混合物を型板上に散布して表層とし、その上にセメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した芯層用原料混合物を散布積層して芯層とし、さらにその上にセメント系無機材料とケイ酸含有物質と木質補強材とマイカと水酸化物とを主原料として混合した表裏層用原料混合物を散布して裏層として三層構造とするか、または、裏層を成形しないで二層構造とした積層物を圧締して水分存在下でオートクレーブ硬化養生するので、防火耐火性能に優れた木質セメント板を製造することが出来る。
【００３１】
また、本発明によれば、前記表裏層用原料混合物および芯層用原料混合物を準備する際、木質補強材と水酸化物とを先に混合し、そのあと残りの原料を混合するので、木質補強材の表面に水酸化物がコーティングされた状態を準備することが出来、その結果、木質補強材からのセメント硬化阻害物質の発生を抑えることが出来、強度低下を起こさず、防火耐火性能が向上する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wood cement board suitable for a building board such as an outer wall material, and more particularly to a wood chip cement board and a method for producing the same.
[0002]
[Prior art]
Conventionally, various methods have been studied with regard to fire prevention performance in the case of a fire in a wood cement board.
It is necessary to devise a technique that prevents the fire from turning inside the structure under a combustion condition such as a fire. For this purpose, a base material that causes less base material shrinkage during combustion is required.
As a representative method, there is a method of adding asbestos, but asbestos is one of carcinogenic substances, and environmental pollution becomes a problem due to scattering of asbestos fine powder, and handling is difficult.
Moreover, in order to suppress the shrinkage | contraction of the base material at the time of combustion, adding mica has been performed conventionally. (For example, Japanese Patent No. 2754306)
Furthermore, magnesium hydroxide or aluminum hydroxide is added to improve fireproof performance, and it is also added in combination with mica. (For example, JP-A-6-345508)
[0003]
[Problems to be solved by the invention]
However, Japanese Patent Laid-Open No. 6-345508 is a wet manufacturing method, and the wood reinforcing material is pulp, so that it is not necessary to consider the cement hardening inhibition, and so-called wood chip cement board using wood pieces as the wood reinforcing material. Fire resistance, incombustibility, and fire resistance have not been fully studied.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present onset Ming, and the surface or the front and back layer of dense structure in which the cementitious inorganic material and siliceous material and wood reinforcement and mica and a hydroxide as the main raw material, cementitious inorganic It is characterized by being a wood cement board having a core layer having a rough structure mainly composed of a material, a silicic acid-containing substance, a wood reinforcing material, mica and hydroxide.
According to the said structure, the wood cement board excellent in fireproofing fireproof performance can be provided.
[0005]
The present onset Akira is characterized in that the hydroxide is aluminum hydroxide.
According to the said structure, the wood cement board excellent in fireproofing fireproof performance can be provided.
[0006]
The present onset bright, the mica is characterized in that it is added 15 wt% to 25 wt% with respect to the total feed. According to the above configuration, it is possible to provide a wood cement board that does not cause strength reduction and is excellent in fireproofing and fireproofing performance.
[0007]
The present onset Ming, the hydroxide is characterized in that it is added over 10 to 20 mass% relative to the total feed.
According to the above configuration, it is possible to provide a wood cement board that does not cause strength reduction and is excellent in fireproofing and fireproofing performance.
[0008]
The present onset Ming, wood reinforcement of the surface layer or the front and back layers with wood flour and / or wood chips, and wherein the wood reinforcement of the core layer is wood and / or wood fiber bundles.
According to the said structure, even if it uses the wood piece etc. with many hardening inhibiting substances, intensity | strength does not raise | generate, and the wood cement board excellent in fire-proof fire resistance performance can be provided.
[0009]
In addition, as a method for producing a wood cement board according to the present invention, a raw material mixture for front and back layers, which is obtained by mixing a cement-based inorganic material, a silicic acid-containing substance, a wood reinforcing material, mica and a hydroxide as main raw materials, is formed on a template. Sprinkled on the surface layer, and a core layer raw material mixture in which a cement-based inorganic material, a silicic acid-containing substance, a wood reinforcing material, mica, and a hydroxide are mixed as main materials is sprayed and laminated to form a core layer. Furthermore, a three-layer structure is formed as a back layer by spraying a raw material mixture for the front and back layers mixed with a cement-based inorganic material, a silicic acid-containing material, a wood reinforcing material, mica and a hydroxide as main materials, or The laminate having a two-layer structure without pressing the back layer is pressed and cured by autoclaving in the presence of moisture.
According to the said structure, the wood cement board excellent in fireproofing fireproof performance can be manufactured.
[0010]
The present onset Ming, when preparing the front and back layer material mixture and a core layer material mixture, as characterized by a wood reinforcement and hydroxide are mixed first, mixed Then the remaining ingredients Yes.
According to the above configuration, it is possible to prepare a state in which hydroxides on the surface of the wood reinforcement is co computing, as a result, it is possible to suppress the occurrence of cement inhibitor from wood reinforcement, strength The fire and fire resistance performance is improved without causing a decrease.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described.
[Cement-based inorganic materials]
Examples of the cement-based inorganic material used in the present invention include cements such as Portland cement, blast furnace slag cement, silica cement, fly ash cement, alumina cement, and white cement.
Two or more of the above cements may be used in combination.
[0012]
[Silica-containing substances]
Examples of the silicic acid-containing substance used in the present invention include silicic acid-containing substances such as silica sand, quartzite powder, silica powder, silica fume, fly ash, blast furnace slag, shirasu balloon, pearlite, diatomaceous earth, and dolomite. .
Two or more of the above silicic acid-containing substances may be used in combination.
[0013]
[Wood reinforcement]
As the wood reinforcing material used in the present invention, wood flour, wood wool, wood chips, wood fiber, wood pulp, wood fiber bundle, dry pulp, kenaf, bamboo fiber, hemp fiber, bacus, rice bran, rice straw, etc. are used. Is done.
It is preferable to use a fine wood reinforcing material for the surface layer or the front and back layers, for example, it is preferable to use wood flour or wood fragments, particularly preferably 20-50 mesh wood flour, width 0.5- It is a wood piece of 2.0 mm, a length of 1.0 to 10.0 mm, and an aspect ratio (length / thickness) of 20 to 30.
By using a fine wood reinforcing material for the front or back layer, the density of the front or back layer becomes dense and contributes to the improvement of fire resistance.
It is preferable to use a coarse wood reinforcing material for the core layer, for example, it is preferable to use a piece of wood or a wood fiber bundle, and particularly preferred is a width of 0.5 to 3.0 mm and a length of 1.0 to Wood pieces of 20 mm, aspect ratio (length / thickness) of 20-30, branch and / or bent and / or bent wood fibers having a diameter of 0.1-2.0 mm and a length of 2.0-35.0 mm It is a bunch.
By using a rough wood reinforcing material for the core layer, the wood cement board is provided with cushioning properties, and when the surface is provided with an uneven pattern, a very clear and deep uneven pattern can be formed.
Two or more kinds of the wood reinforcing materials may be mixed.
Moreover, what was reproduced | regenerated from the wood scrap as a wood reinforcement can also be used.
[0014]
[Mica]
The mica used in the present invention is a flake having an average particle size of 150 μm or more and an aspect ratio of 65 or more, and particularly preferably an average particle size of 340 μm or more and an aspect ratio of 80 or more.
If the average particle size is less than 150 μm, the particle size is small, so that the bonding area between mica is small, and it is difficult to obtain dimensional stability due to sufficient suppression of substrate shrinkage.
Mica is a highly elastic body that usually has a layered structure, does not absorb moisture, and has rigidity, and can greatly improve the dimensional stability of a wood cement board including a wood reinforcing material.
[0015]
[hydroxide]
Examples of the hydroxide used in the present invention include aluminum hydroxide, magnesium hydroxide, zinc hydroxide, etc., but aluminum hydroxide causes a decomposition reaction between aluminum oxide and water under a high heat around 200 to 300 ° C., Since this reaction is an endothermic reaction, it has the effect of relaxing the heat of combustion and delaying the influence of heat on other substances (such as wood chips) in the plate, and therefore, the fireproof and fireproof performance is improved, which is particularly preferable.
[0016]
[Third component]
The raw material of the wood cement board of the present invention includes, as components other than the above, pulverized waste material of wood cement board, mineral powder such as bentonite and vermiculite, wax, wax, paraffin, silicon, surfactant, etc. Waterproofing agent, water repellent, foaming thermoplastic beads, plastic foam, etc., calcium chloride, magnesium chloride, potassium sulfate, calcium sulfate, magnesium sulfate, aluminum sulfate, sodium aluminate, potassium aluminate, formic acid Cement hardening accelerators such as calcium, calcium acetate, calcium acrylate and water glass may be added.
[0017]
[Composition of wood cement board]
The raw material mixture of the front and back layers of the wood cement board of the present invention is 30% by mass to 60% by mass of the cementitious inorganic material, 10% by mass to 30% by mass of the silicic acid-containing substance, and 5% by mass or more of wood powder and / or wood pieces 15% by mass or less, mica 15% by mass or more and 25% by mass or less, preferably 10% by mass or more and 20% by mass or less of hydroxide, and the raw material mixture of the core layer is 30% by mass or more and 60% by mass of the cementitious inorganic material. % Or less, silicic acid-containing substance 10% by mass to 30% by mass, wood piece or / and wood fiber bundle 5% by mass to 15% by mass, mica 15% by mass to 25% by mass, hydroxide 10% by mass to 20% It is preferable to contain a mass% or less.
When mica is less than 15% by mass, it is difficult to obtain dimensional stability as a wood chip cement board, and when it is more than 25% by mass, mica is in a flat laminated form, and therefore, a cement-based inorganic material that is a binder component, silicic acid The contained materials are difficult to bond with other matrices, and the raw materials are not uniformly mixed and dispersed, resulting in a reduction in fireproof and fireproof performance and strength.
Moreover, the addition ratio of the mica added to the front and back layers and the mica added to the core layer is preferably the same as the addition ratio of the base material between the front and back layers and the core layer is eliminated.
If the hydroxide content is less than 10% by mass, the fire and fire resistance performance cannot be improved so much, and if it is more than 20% by mass, the fire resistance and fire resistance performance will not be improved drastically.
When the wood reinforcing material is less than 5% by mass, the reinforcing effect is not exhibited, and when it is more than 15% by mass, the fire resistance cannot be maintained.
[0018]
[Manufacturing method of wood cement board]
As a manufacturing method of the wood cement board of this invention, a dry type or a semi-dry type manufacturing method is preferable.
In the semi-dry production method, first, a predetermined amount of water is added to and mixed with the raw material mixture containing the cement-based inorganic material, silicic acid-containing substance, wood reinforcing material, mica and hydroxide, and the raw material mixture for the front and back layers After that, a core layer obtained by adding a predetermined amount of water to a raw material mixture containing a cement-based inorganic material, a silicic acid-containing substance, a wood reinforcing material, mica, and a hydroxide is applied on the template as a surface layer. A raw material mixture is spread and laminated to form a core layer, and a front and back layer raw material mixture is spread and laminated to form a three-layer structure as a back layer, or a two-layer structure is formed without forming a back layer. Form the object mat.
Here, the template is not particularly limited as long as it is a support plate on which a mat is formed by receiving the raw material to be dispersed, such as an embossed pattern or a conveying plate.
As the wood reinforcing material, it is preferable to add wood powder or / and wood pieces to the front and back layers, and wood pieces or / and wood fiber bundles to the core layer.
In the dry production method, the above raw material mixture is spread on a template without adding moisture to form a laminate mat, and a predetermined amount of water is added to the mat.
When preparing the raw material mixture for the front and back layers and the raw material mixture for the core layer, it is preferable to mix the wood reinforcing material and the hydroxide first, and then mix the remaining raw materials.
In particular, when the wood reinforcing material is a piece of wood, the hydroxide is coated around the surface of the piece of wood, so there is an effect of blocking the influence of heat on the piece of wood, and the cement generated from the piece of wood during heating and water addition Hardening inhibitory substances are not easily generated, and therefore the hardening of the cement proceeds before the cement hardening inhibitory substances are generated, so that the strength is not lowered. When spraying the above raw material mixture on the template, the raw material mixture is sequentially sprayed on the template while transporting the template by arranging a plurality of templates on the conveyor. When air is blown and selected, fine components in the raw material mixture are distributed more to the template side (front side), and coarse components are distributed more to the opposite side of the template (back side) to obtain a dense surface. It is done.
Moreover, since the mica tends to be oriented in the thickness direction of the mat at the time of the wind selection, the mica is laminated in the thickness direction in the mat, and the dimensional stability by suppressing the shrinkage of the base material is excellent. Since it can also suppress the conduction, it also contributes to fire prevention performance.
Then, the formed laminated mat is pressed at a pressure of 2 to 5 MPa and firstly cured at 60 to 80 ° C. for 8 to 12 hours, and further at a pressure of 160 ° C. or higher, preferably 0.5 MPa or higher. Perform autoclaving.
In the production process of the above-mentioned wood cement board, the siliceous component and the alumina component are slightly eluted from the mica surface by the autoclave curing at a temperature of 160 ° C. or higher, preferably 0.5 MPa or higher, Therefore, the mica surface becomes rough, and the overlapping area between mica is increased.
For this reason, the calcium content eluted from the cement-based inorganic material easily enters between the overlapping parts of the mica in the overlapping part of the mica, and this calcium content reacts with the siliceous component eluted from the mica surface to stabilize the silicic acid. Calcium reactants are generated, and the reactants adhere to each other, and the mica adheres to the large overlapping area of each other, that is, the adhesion area, so that the mica is firmly joined.
As a result, the wood cement board of the present invention obtains large mechanical strength, greatly improved dimensional stability, fireproof and fireproof performance.
[0019]
【Example】
Examples of the present invention will be given below.
[0020]
[Examples 1-7]
A mixture having the composition shown in Table 1 was prepared as a raw material for the wood cement board.
As a raw material for the front and back layers, as a wood reinforcing material, a major axis of 1.0 to 10.0 mm, a minor axis of 0.5 to 2.0 mm, an aspect ratio of 20 to 30, a piece of wood is used, and mica has an average particle size of 340 μm, The one having an aspect ratio of 80 was used, aluminum hydroxide was used as the hydroxide, water was added as an external addition relative to the total solid content, and the curing agent was water glass as an external addition relative to the cement.
As a raw material for the core layer, as a wood reinforcing material, the major axis is 10 to 20 mm, the minor axis is 0.5 to 3.0 mm, the aspect ratio is 20 to 30, the piece of wood, the diameter is 0.1 to 2.0 mm, and the length is 2 to 35 mm. Branched and / or bent and / or bent wood fiber bundles were used, and the other raw materials were the same as those of the front and back layers.
First, of the raw materials for the front and back layers, wood pieces and aluminum hydroxide were stirred and mixed with a stirring device such as an Eirich mixer.
Then, the other raw material of the front and back layers was mixed, and it was set as the mixture for front and back layers.
Apart from this, among the raw materials for the core layer, wood chips, wood fiber bundles and aluminum hydroxide were stirred and mixed, and then other raw materials of the core layer were mixed to obtain a mixture for the core layer.
Then, while arranging a plurality of templates on a conveyor and conveying the templates, this front and back layer raw material mixture is sequentially spread on the template to form a surface layer, and the core layer raw material mixture is spread and laminated thereon. A core layer was formed, and a raw material mixture for the front and back layers was spread and laminated thereon to form a three-layer structure mat as a back layer.
The formed mat was pressed at a pressure of 3 MPa and first cured at 70 ° C. for 10 hours. After demolding, the autoclave was cured at 165 ° C. for 7 hours. went.
[0021]
[Comparative Examples 1-4]
With the raw material mixture shown in Table 2, a wood cement board was produced under the same conditions as in the Examples.
[0022]
[Table 1]

[0023]
[Table 2]

[0024]
The bending strength conformed to JIS A1408.
Combustion shrinkage is calculated by the test piece dimensions before and after the combustion test (900 ° C, 1 hour combustion test piece 7 x 20 cm in an electric furnace), ◎-good, ○-no problem as a product, △ -Evaluation was made in four stages of x-defect, which is a problem as a product.
Cracks during combustion are visually observed for the condition of the test piece surface and small cracks after the combustion test. ◎-Good (no cracks almost), ○-No problem as products (small cracks), △-Problems as products Evaluation (in the crack), x-defect (crack many), was evaluated in four stages.
In Examples 1 to 7 in which 15 to 25% by mass of mica and 10 to 20% by mass of aluminum hydroxide were added, the bending strength was reduced as compared with Comparative Example 1 (blank) in which asbestos was added instead of mica. There was no combustion shrinkage and cracking during combustion.
In Comparative Example 2 in which only aluminum hydroxide was added, the strength was not reduced, but the combustion shrinkage was poor, and the cracks during combustion were slightly reduced.
In Comparative Example 3 in which only mica was added, the strength did not decrease, but the combustion shrinkage slightly decreased and the cracks during combustion also decreased slightly.
In Comparative Example 4 in which only 7% by mass of mica and aluminum hydroxide were added, the strength was not reduced, but the combustion shrinkage was reduced and the cracks during combustion were slightly reduced.
[0025]
As described above, according to this onset bright, and the surface or the front and back layer of dense structure in which the cementitious inorganic material and siliceous material and wood reinforcement and mica and a hydroxide as the main raw material, cementitious inorganic A wood cement board having a core layer having a coarse structure mainly composed of a material, a silicic acid-containing substance, a wood reinforcing material, mica, and a hydroxide, and provides a wood cement board having excellent fire resistance and fire resistance. I can do it.
[0026]
Further, according to this onset bright, wherein since the hydroxide is aluminum hydroxide, it is possible to provide a superior wood cement board to fire fire performance.
[0027]
Further, according to this onset bright, since the mica is added 25 wt% or less than 15% by weight relative to the total feed, without causing strength reduction, moreover, provides a good wood cement board fireproof fire resistance I can do it.
[0028]
Further, according to this onset bright, because the hydroxide is added over 10 to 20 mass% relative to the total feed, without causing strength reduction, moreover, wood cement board with excellent fire fire resistance Can be provided.
[0029]
Further, according to this onset bright, wood reinforcement of the surface layer or the front and back layers with wood flour and / or wood chips, wood reinforcement of the core layer since it is wood and / or wood fiber bundles, with much cure inhibitor Even if wood pieces or the like are used, it is possible to provide a wood cement board that does not cause strength reduction and has excellent fire and fire resistance.
[0030]
Further, according to this onset bright, and the surface layer of cement based inorganic material and siliceous material and the front and back layer raw material mixture wood reinforcement and mica and the hydroxide are mixed as the main raw material sprayed on the mold board Furthermore, a core layer raw material mixture in which a cement-based inorganic material, a silicic acid-containing substance, a wood reinforcing material, mica and a hydroxide are mixed as a main material is sprayed and laminated to form a core layer, and a cement system is further formed thereon. Scatter the raw material mixture for the front and back layers mixed with inorganic material, silicic acid-containing material, wood reinforcing material, mica and hydroxide as the main raw material to form a three-layer structure as the back layer, or do not mold the back layer in so O over Tokure over to Bed hardening and curing in the presence of moisture by pressing the laminate in which a two-layer structure, it is possible to produce a superior wood cement board to fire fire performance.
[0031]
Further, according to this onset bright, when preparing the front and back layer material mixture and a core layer material mixture, and a hydroxide wood reinforcement mixed previously, since mixing Then the remaining ingredients, can be prepared state hydroxide on the surface of the wood reinforcement is co computing, as a result, it is possible to suppress the occurrence of cement inhibitor from wood reinforcement, without causing decrease in strength, fire Fire resistance is improved.

Claims

A surface layer or front and back layers of a dense structure mainly composed of a cement-based inorganic material, a silicic acid-containing substance, a wood reinforcing material, mica and a hydroxide,
A wood cement board having a cemented inorganic material, a silicic acid-containing substance, a wood reinforcing material, a core layer having a rough structure mainly composed of mica and hydroxide ,
Cement-based inorganic material is a mixture of one or more of Portland cement, blast furnace slag cement, silica cement, fly ash cement, alumina cement, white cement,
Silica-containing material is a mixture of one or more types of silica sand, silica stone powder, silica powder, silica fume, fly ash, blast furnace slag, shirasu balloon, perlite, diatomaceous earth, and dolomite.
The wood reinforcing material of the surface layer or the front and back layers is 20-50 mesh wood flour or / and width 0.5-2.0 mm, length 1.0-10.0 mm, aspect ratio (length / thickness) 20-30. A piece of wood
The wood reinforcing material of the core layer has a width of 0.5 to 3.0 mm, a length of 1.0 to 20 mm, an aspect ratio (length / thickness) of 20 to 30 wood pieces and / or a diameter of 0.1 to 2.0 mm, Branches and / or bent and / or bent wood fiber bundles having a length of 2.0 to 35.0 mm,
The hydroxide is aluminum hydroxide,
The surface layer or the front and back layers are 30% by mass or more and 60% by mass or less of a cement-based inorganic material, 10% by mass or more and 30% by mass or less of a silicic acid-containing substance, 5% by mass or more and 15% by mass or less of a wood reinforcing material, and 15% of mica. Containing 10% by weight or more and 20% by weight or less of hydroxide,
The core layer is composed of 30% to 60% by mass of a cement-based inorganic material, 10% to 30% by mass of a silicic acid-containing substance, 5% to 15% by mass of a wood reinforcing material, and 15% by mass of mica. 25% by mass or less, 10% by mass or more and 20% by mass or less of hydroxide,
The surface layer or the front and back layers contain a wood reinforcing material finer than the core layer, and the density of the surface layer or the front and back layers is denser than the core layer,
It has a dense surface with many fine components distributed on the surface side and many coarse components distributed on the back side, and mica is laminated in the thickness direction,
Hydroxide coating is applied to the surface of the wood reinforcing material of the front or back layer and the core layer
A wood cement board characterized by that.

A raw material mixture for the front and back layers, which is a mixture of cement-based inorganic material, silicic acid-containing material, wood reinforcing material, mica and hydroxide, is sprinkled on the template to form a surface layer. A core layer raw material mixture in which silicate-containing material, wood reinforcing material, mica and hydroxide are mixed as main ingredients is sprayed and laminated to form a core layer, on which cement-based inorganic material, silicate-containing substance and wood Scatter the raw material mixture for the front and back layers mixed with the reinforcing material, mica and hydroxide as the main raw material to make a three-layer structure as the back layer, or a laminate with a two-layer structure without forming the back layer in pressing to dry or semi-dry method for producing O over Tokure over Bed hardening and curing to that wood cement board in the presence of water,
As a cement-based inorganic material, use a mixture of Portland cement, blast furnace slag cement, silica cement, fly ash cement, alumina cement, white cement,
As a silicic acid-containing substance, use a mixture of one or more types of silica sand, silica stone powder, silica powder, silica fume, fly ash, blast furnace slag, shirasu balloon, perlite, diatomaceous earth, dolomite,
As a wood reinforcing material for the front or back layer, 20 to 50 mesh wood flour or / and width 0.5 to 2.0 mm, length 1.0 to 10.0 mm, aspect ratio (length / thickness) 20 to 30 Use a piece of wood,
As a wood reinforcing material for the core layer, a width of 0.5 to 3.0 mm, a length of 1.0 to 20 mm, an aspect ratio (length / thickness) of 20 to 30 wood pieces and / or a diameter of 0.1 to 2.0 mm, Using branches and / or bent and / or bent wood fiber bundles having a length of 2.0 to 35.0 mm,
Use aluminum hydroxide as hydroxide,
The composition of the raw material mixture for the front and back layers is 30% by mass to 60% by mass of the cement-based inorganic material, 10% by mass to 30% by mass of the silicic acid-containing substance, and 5% by mass to 15% by mass of the wood reinforcing material. Mica is 15% by mass to 25% by mass, hydroxide is 10% by mass to 20% by mass,
The composition of the core layer raw material mixture is 30% by mass to 60% by mass of the cement-based inorganic material, 10% by mass to 30% by mass of the silicic acid-containing substance, and 5% by mass to 15% by mass of the wood reinforcement. Mica is 15% by mass to 25% by mass, hydroxide is 10% by mass to 20% by mass,
When preparing the raw material mixture for the front and back layers and the raw material mixture for the core layer, the wooden reinforcement and the hydroxide are mixed first, and then the remaining raw materials are mixed, and the surface of the wooden reinforcement is made of hydroxide. Coated,
When spraying the raw material mixture sequentially on the template while transporting the template while arranging the multiple templates on the conveyor, wind selection is performed by blowing air in the direction opposite to the template conveying direction. A large amount of fine components are distributed on the template side, and a large amount of coarse components are distributed on the opposite side of the template to obtain a dense surface and mica is laminated in the thickness direction.
A method for producing a wood cement board characterized by the above.