JP3783736B2 - Calcium silicate plate manufacturing method - Google Patents
Calcium silicate plate manufacturing method Download PDFInfo
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- JP3783736B2 JP3783736B2 JP13804095A JP13804095A JP3783736B2 JP 3783736 B2 JP3783736 B2 JP 3783736B2 JP 13804095 A JP13804095 A JP 13804095A JP 13804095 A JP13804095 A JP 13804095A JP 3783736 B2 JP3783736 B2 JP 3783736B2
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/18—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing mixtures of the silica-lime type
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/40—Porous or lightweight materials
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Description
【０００１】
【産業上の利用分野】
本発明は、珪酸カルシウム板の製造方法に関し、更に詳細には軽量（例えば嵩比重１．０以下）珪酸カルシウム板の製造方法に関する。
【０００２】
【従来の技術・課題】
従来、珪酸カルシウム板は、軽量で、優れた加工性及び寸法安定性をもち、更に不燃性であるという特徴を有し、建築材料として主として内装用に広く使用されている。このような珪酸カルシウム板の成形法として、抄造法、プレスモールド法及び単層成形法などが利用され、石灰質原料、珪酸質原料、無機質充填剤を含有してなる原料スラリーから成形された成形体を、通常は圧力容器内で飽和水蒸気により反応硬化することにより珪酸カルシウム板が製造されている。
【０００３】
しかし、特に抄造法において、軽量珪酸カルシウム板を製造する場合には、水熱反応前の成形体の層間強度が弱く、また、含有水分量が多いため、水熱反応中に余剰水の熱膨張が生じたり、蒸気圧が高くなり、層間剥離やパンクといった問題を生ずることがある。
【０００４】
これらの問題を防止するために、成形後にプレスを行い、その後に水熱反応を行ったり、水熱反応中にターンバックルを用いて締め付けるという方法が行われているが、これらの方法を講ずると嵩比重が高くなったり、製造に人手が掛かるといった欠点があった。
【０００５】
また、特開平６−２８７０８３号公報に示されている余剰水の除去方法もあるが、特殊な容器あるいは蒸気の過熱器を必要とするため一般的な方法とは言えない。
【０００６】
更に、本発明者らは、既に特願平６−323225号及び特願平７−5013号に、珪酸質原料の一部として石灰質原料との反応性が良い非晶質珪酸原料や珪酸塩原料を用いたり、ポルトランドセメントや高炉水砕スラグといった硬化剤を添加する方法を提案しているが、高価な原料を使用したり、嵩比重を高くするといった欠点がある。
【０００７】
従って、本発明の目的は、非晶質珪酸原料や珪酸塩原料あるいはポルトランドセメントや高炉水砕スラグといった硬化剤を添加しないでも、半水石膏を用いることにより水熱反応前の成形体（グリーンシート）の強度及び層間強度が向上し、水熱反応中に層間剥離やパンクを生ずることがない軽量珪酸カルシウム板の製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
即ち、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、原料スラリーが半水石膏を固形分として５〜４０重量％及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【０００９】
また、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうち少なくとも一方が半水石膏を固形分としてで５〜４０重量％及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【００１０】
更に、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、抄造機のリターンロールとメーキングロールの間の抄造フィルム上に、半水石膏粉体を１０〜５０ｇ／ｍ２の割合で散布しながら積層して所定の厚さに積層後、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【００１１】
また、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、抄造機のリターンロールとメーキングロールの間の抄造フィルム上に、固形分として半水石膏と半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなるスラリーを半水石膏固形分換算量で１０〜５０ｇ／ｍ2の割合で散布しながら積層して所定の厚さに積層後、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【００１２】
更に、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうちのどちらか一方が固形分として半水石膏９２〜９８重量％、繊維質原料２〜８重量％及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、該スラリーによる抄造厚を丸網式抄造機のフェルトが一周する間に抄造される全抄造厚の１〜１０％とし、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【００１３】
また、本発明は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる原料スラリーを抄造法により積層して得られた成形体を、圧力容器中で水熱反応させることからなる珪酸カルシウム板の製造方法において、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうちのどちらか一方が固形分として半水石膏４０重量％超え９８重量％未満、繊維質原料２〜８重量％、石灰質原料及び無機質充填材からなる群から選択される１種または２種以上の成分を５８重量％以下及び半水石膏に対して外割で０．０５〜０．５重量％の凝結遅延剤を含有してなり、該スラリーによる抄造厚を丸網式抄造機のフェルトが一周する間に抄造される全抄造厚の１〜１０％とし、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことを特徴とする軽量珪酸カルシウム板の製造方法に係る。
【００１５】
【作用】
本発明の軽量珪酸カルシウム板（以下、単に「珪酸カルシウム板」と記載する）の製造方法に使用される原料スラリーの基本組成は、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％及び無機質充填材５〜３０重量％を含有してなる慣用のものである。
【００１６】
ここで、石灰質原料としては、例えば消石灰、生石灰などを使用することができる。なお、石灰質原料の配合量が１７重量％未満であったり、５０重量％を超えると曲げ強度が低く、吸水による寸法変化率が大きくなるために好ましくない。
【００１７】
また、珪酸質原料としては例えば珪砂、珪藻土、フライアッシュ等を使用することができる。なお、珪素質原料の配合量が１５重量％未満であったり、４５重量％を超えると曲げ強度が低く、吸水による寸法変化率が大きくなるために好ましくない。
【００１８】
また、石灰質原料と珪酸質原料については、上記割合のうち、石灰質原料２〜２０重量％と珪酸質原料３〜２５重量％を予めゲル化して使用することができる。ゲル化条件の例としては、７５〜９０℃の温度で１.５〜４時間が挙げられる。
【００１９】
更に、繊維質原料としては、例えばセルロース繊維、ポリプロピレン、ビニロン、ガラスファイバー、カーボンファイバー等を使用することができる。なお、繊維質原料の配合量が２重量％未満であると、曲げ強度が低くなるために好ましくなく、８重量％を超えると不燃性でなくなるために好ましくない。また、ポリプロピレン、ビニロン、ガラスファイバー、カーボンファイバー等を使用する場合、それらの配合量は５重量％以下とすることが好ましい。
【００２０】
また、無機質充填剤としては、例えばパーライト、ウォラストナイト、マイカ、タルク、炭酸カルシウム、２水石膏などを使用することができる。なお、無機質充填剤の配合量が５重量％未満であると、吸水による寸法変化率が大きくなるために好ましくなく、３０重量％を超えると曲げ強度が低下するために好ましくない。
【００２１】
本発明の特徴は、珪酸カルシウム板の製造方法としての以下の６つの方法である：
本発明の第１発明に係る製造方法によれば、上述のような成分配合を有する原料スラリーに半水石膏を５〜４０重量％及び半水石膏に対し外割で０.０５〜０.５重量％の凝結遅延剤を含有させ、この原料スラリーを抄造法により積層して成形し、次に、得られた成形体を１次養生することにより半水石膏を水和させたのち、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００２２】
即ち、第１発明で使用する原料スラリーは、固形分として石灰質原料１７〜５０重量％、珪酸質原料１５〜４５重量％、繊維質原料２〜８重量％、半水石膏５〜４０重量％、無機質充填材５〜３０重量％、及び半水石膏に対し外割で０.０５〜０.５重量％の凝結遅延剤を含有してなるものである。ここで、半水石膏の配合量が５重量％未満であると、グリーンシートの層間強度の発現性が悪いために好ましくなく、４０重量％を超えるとそれに伴い使用する凝結遅延剤の使用量も増え、原料費が高くなり、また、曲げ強度が低くなるために好ましくない。なお、半水石膏の配合量は１０〜３５重量％が好ましい。
【００２３】
なお、半水石膏をスラリー状態で使用すると非常に水和速度が早いため、凝結遅延剤の原料スラリーへの添加が必須となる。ここで、凝結遅延剤の配合量が半水石膏に対して外割で０.０５重量％未満であると、凝結遅延効果を発現できず原料スラリーを抄造する前に水和が完了してしまい、グリーンシートの層間強度の発現に寄与しないために好ましくなく、また、凝結遅延剤の配合量が０.５重量％を超えると、抄造後、成形体中の半水石膏を水和するための１次養生に非常に時間が掛かり、充分な水和を行うことができず、また、成形体強度も弱くなるために好ましくない。即ち、半水石膏に対して０.０５〜０.５重量％の凝結遅延剤を配合することにより、半水石膏の水和反応をスラリー調製後約１０〜２０時間程度遅延することができので、スラリー調製後約６〜１５時間の間にグリーンシートの作製を完了するれば本発明の効果を得ることができる。
【００２４】
次に、本発明の第２発明に係る製造方法によれば、上述のような成分配合を有する原料スラリーを抄造法により積層して成形するにあたり、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうち少なくとも一方が半水石膏を固形分として５〜４０重量％及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００２５】
即ち、第２発明においては、上記第１発明に使用する原料スラリーと同一組成のスラリーを丸網式抄造機の１番目及び／または最後の抄箱のスラリーとして使用するものである。ここで、１番目及び／または最後の抄箱に使用するスラリー中の半水石膏の配合量が固形分として５重量％未満であると、グリーンシートの層間強度の発現性が悪いために好ましくなく、また、４０重量％を超えるとそれに伴い使用する凝結遅延剤の使用量も増え、原料費が高くなり、また、曲げ強度が低くなるために好ましくない。
【００２６】
なお、半水石膏をスラリー状態で使用すると非常に水和速度が早いため、凝結遅延剤をスラリーへ添加することが必須となる。凝結遅延剤の配合量が半水石膏に対して外割で０.０５重量％未満であると、凝結遅延効果を発現できず、スラリーを抄造する前に水和が完了してしまい、グリーンシートの層間強度の発現に寄与しないために好ましくなく、また、凝結遅延剤の配合量が０.５重量％を超えると、抄造後、成形体中の半水石膏を水和するための１次養生に非常に時間が掛かり、充分な水和を行うことができず、また、成形体強度も弱くなるために好ましくない。
【００２７】
本発明の第２発明によれば、基本配合の原料スラリーに、更に半水石膏及び凝結遅延剤を添加してなるスラリーを丸網式抄造機の１番目及び／または最後の抄箱へ入れ、抄造法により積層して成形する。このスラリーの抄造機の１番目及び／または最後の抄箱への入れ方は、特に限定されるものではなく、例えば他の抄箱と配合割合の異なるスラリーを作製し、専用のチェストから送っても良いし、チェストと抄箱の間の樋で、半水石膏及び凝結遅延剤それぞれのスラリーを他のスラリーに添加しても良い。
【００２８】
次に、本発明の第３発明に係る製造方法によれば、上述のような基本組成を有する原料スラリーを抄造法により積層して成形するにあたり、抄造機のリターンロールとメーキングロールの間の抄造フィルム上に、半水石膏粉体を１０〜５０ｇ／ｍ2の割合で散布しながら積層して所定の厚さの積層後、得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００２９】
ここで、半水石膏粉体の散布量が１０ｇ／ｍ2未満では層間強度の発現性が悪いために好ましくなく、また、半水石膏粉体の散布量が５０ｇ／ｍ2を超えると半水石膏の層ができ、乾燥時にクラックが入ったり、曲げ強度が低くなるために好ましくない。
【００３０】
なお、本発明の第３発明に使用可能な丸網式抄造機の一例を図１に示す。この丸網式抄造機によれば、抄箱(6)中に設けられた丸網シリンダー(8)によりスラリー(7)を抄き上げフェルト(3)に転写し、この操作を抄箱(丸網シリンダー)の数だけ反復して抄造フィルム(4)とし、更に、この抄造フィルム(4)をメーキングロール(1)で所定の厚さまで所定回数巻き付けた後切断することにより、グリーンシートを得ることができる。一般に、層間剥離やパンクは、メーキングロール(1)で重ね合わせたフィルム間で起こるため、リターンロール(2)とメーキングロール(1)の間に散布装置(5)を設置して半水石膏粉体を散布することにより、上記フィルム間の密着力(層間強度)を向上することにより層間剥離やパンクを防止することができる。
【００３１】
次に、本発明の第４発明に係る製造方法によれば、上述のような基本組成を有する原料スラリーを抄造法により積層して成形するにあたり、抄造機のリターンロールとメーキングロールの間の抄造フィルム上に、半水石膏と半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなる散布用スラリーを半水石膏固形分換算量で１０〜５０ｇ／ｍ2の割合で散布しながら積層して所定の厚さに積層後、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００３２】
散布用スラリーの散布量が半水石膏固形分換算量で１０ｇ／ｃｍ2未満では層間強度の発現性が悪いために好ましくなく、また、該スラリーの散布量が半水石膏固形分換算量で５０ｇ／ｃｍ2を超えると半水石膏の層ができ、乾燥時にクラックが入ったり、曲げ強度が低くなるために好ましくない。ここで、散布用スラリーの固形分濃度は特に限定されるものではないが、通常５〜２０重量％、好ましくは８〜１５重量％程度と抄造に一般的に用いられるスラリーの固形分濃度よりも若干固形分濃度の高いものが好ましい。
【００３３】
なお、散布用スラリーにて半水石膏を散布する場合には、半水石膏は非常に水和速度が早いため、凝結遅延剤を散布用スラリーへ添加することが必須となる。凝結遅延剤の配合量が半水石膏に対して外割で０.０５重量％未満であると、凝結遅延効果を発現できず、スラリーを抄造する前に水和が完了してしまい、グリーンシートの層間強度の発現に寄与しないために好ましくなく、また、凝結遅延剤の配合量が０.５重量％を超えると、抄造後、成形体中の半水石膏を水和するための１次養生に非常に時間が掛かり、充分な水和を行うことができず、また、成形体強度も弱くなるために好ましくない。
【００３４】
次に、本発明の第５発明に係る製造方法によれば、上述のような基本組成を有する原料スラリーを抄造法により積層して成形するにあたり、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうちのどちらか一方が固形分換算量で半水石膏９２〜９８重量％、繊維質原料２〜８重量％及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、該スラリーによる抄造厚を丸網式抄造機のフェルトが一周する間に抄造される全抄造厚の１〜１０％、好ましくは１〜５％とし、成形後に半水石膏を水和させ、次に、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００３５】
ここで、前記スラリーによる抄造厚が１％未満では、層間強度の発現性が悪いために剥離が起こり易く好ましくない。また、半水石膏の含有量が９２〜９８重量％と高含量であるスラリーを使用する場合に、抄造厚が１０％を超えると半水石膏の層が厚くなり、水熱反応後の曲げ強度が低下するために好ましくない。
【００３６】
また、繊維質原料としては、セルロース繊維等を用いることができる。なお、半水石膏の配合割合が９８重量％を超えると繊維質原料の配合割合が少なくなり、抄造時に粉体ロスが多くなるために好ましくない。また、繊維質原料の配合割合が８重量％を超えると、繊維質原料の層ができ、剥離し易くなるために好ましくない。
【００３７】
なお、スラリー状態で半水石膏を使用する場合、半水石膏は非常に水和速度が早いため、凝結遅延剤をスラリーへ添加することが必須となる。凝結遅延剤が半水石膏に対して０.０５重量％未満であると、凝結遅延効果を発現できず、スラリーを抄造する前に水和が完了してしまい、グリーンシートの層間強度の発現に寄与しないために好ましくなく、また、凝結遅延剤の配合量が０.５重量％を超えると、抄造後、成形体中の半水石膏を水和するための１次養生に非常に時間が掛かり、充分な水和を行うことができず、また、成形体強度も弱くなるために好ましくない。
【００３８】
半水石膏をスラリー状態で使用する場合、このスラリーの濃度は、他の抄箱の原料スラリーの濃度と同一か、またはそれ以下とするのが好ましく、固形分濃度で１〜１０％、好ましくは３〜７％とするのが好ましい。ただし、丸網へのスラリー固形分の乗り量のロスをできるだけ少なくするように調節するために、抄箱内のスラリー水位を下げたり、シリンダーメッシュを適当な大きさに変更することが必要な場合もある。
【００３９】
次に、本発明の第６発明に係る製造方法によれば、上述のような基本組成を有する原料スラリーを抄造法により積層して成形するにあたり、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうちのどちらか一方が固形分として半水石膏４０重量％超え９８重量％未満、繊維質原料２〜８重量％、石灰質原料及び無機質充填剤からなる群から選択される１種または２種以上の成分を５８重量％以下、及び半水石膏に対して外割で０.０５〜０.５重量％の凝結遅延剤を含有してなり、該スラリーによる抄造厚を丸網式抄造機のフェルトが一周する間に抄造される全抄造厚の１〜１０％、好ましくは１〜５％とし、抄造により得られた成形体を１次養生することにより半水石膏を水和させ、次に、水熱反応を行うことにより珪酸カルシウム板を製造することができる。
【００４０】
該スラリーによる抄造厚が１％未満では、層間強度の発現性が悪いため剥離が起こり易く好ましくない。また、半水石膏の含有量が４０重量％超え９８重量％未満と比較的高含量であるスラリーを使用する場合にも、抄造厚が１０％を超えると半水石膏の層が厚くなり、水熱反応後の曲げ強度が低下する傾向があるために好ましくない。
【００４１】
繊維質原料としては、セルロース繊維等を用いることができる。石灰質原料としては、例えば消石灰、生石灰等を使用することができる。更に、無機質充填剤としては、例えばパーライト、ウォラストナイト、マイカ、タルク、炭酸カルシウム、珪砂、２水石膏等を使用することができる。この石灰質原料及び無機質充填剤からなる群から選択された１種または２種以上を配合することにより、層間強度を維持しつつ、珪酸カルシウム板の原料コストを低下させることができる。半水石膏の配合割合が９８重量％を超えると繊維質原料の配合割合が少なくなり、粉体のロスが多くなるために好ましくなく、また、半水石膏の配合割合が４０重量％以下の場合には、丸網式抄造機の１番目及び最後の抄箱に入れるスラリーのうちのどちらか一方のみのスラリーに半水石膏を配合する場合には配合効果が顕著に現れないために好ましくない。繊維質原料の配合割合が８重量％を超えると繊維質原料の層ができ剥離し易くなるために好ましくない。更に、石灰質原料及び／または無機質充填剤の配合割合が５８重量％を超えるとそれに伴って半水石膏や繊維質原料を充分に配合することができないために好ましくない。
【００４２】
なお、スラリー状態で半水石膏を使用する場合、半水石膏は非常に水和速度が早いため、凝結遅延剤をスラリーへ添加することが必須となる。凝結遅延剤が半水石膏に対して０.０５重量％未満であると、凝結遅延効果を発現できず、スラリーを抄造する前に水和が完了してしまい、グリーンシートの層間強度の発現に寄与しないために好ましくなく、また、凝結遅延剤の配合量が０.５重量％を超えると、抄造後、成形体中の半水石膏を水和するための１次養生に非常に時間が掛かり、充分な水和を行うことができず、また、成形体強度も弱くなるために好ましくない。
【００４３】
上記スラリーの濃度は、他の抄箱の原料スラリーの濃度と同一か、またはそれ以下とするのが好ましく、固形分濃度で１〜１０％、好ましくは３〜７％とするのが好ましい。ただし、丸網へのスラリー固形分の乗り量のロスをできるだけ少なくするように調節するために、抄箱内のスラリー水位を下げたり、シリンダーメッシュを適当な大きさに変更することが必要な場合もある。
【００４４】
本発明に使用する凝結遅延剤は特に限定されるものではなく、グリセリン、アルコール、リン酸塩、カルボン酸、オキシカルボン酸もしくはそれらの塩類及びアミノ酸誘導体などを使用することができる。
【００４５】
抄造により得られた成形体は、１次養生により半水石膏の水和反応を行った後、水熱反応を行う。１次養生の条件は特に限定されるものではなく、半水石膏が水和反応する慣用の条件、好ましくは２０〜６０℃で３時間以上の時間にわたり行うことができる。
【００４６】
上述のような１次養生を行った後の成形体は、慣用の水熱反応条件下で水和反応させ、その後の慣用の工程を経て珪酸カルシウム板とすることができる。なお、水熱反応は、圧力容器中、飽和水蒸気圧下で温度１５０〜２００℃、好ましくは１７０〜１９０℃で５〜２０時間、好ましくは８〜１２時間の条件で行うことができる。
【００４７】
上述のような本発明の第１発明ないし第６発明に係る製造方法により製造された珪酸カルシウム板は、層間剥離強度が曲げ強度(絶乾状態)の３％以上と非常に優れた値を示すものとなる。なお、曲げ強度は、ＪＩＳ Ａ ５４１８に準じて３号試験片で試験した結果であり、層間剥離強度試験は３０×３０ｍｍで行った結果である。
【００４８】
【実施例】
実施例１
表１に示す割合で原料を配合し、１２倍の水で撹拌、混合した。なお、ゲルは消石灰１０重量％、珪藻土１０重量％(重量比１：１)を９０℃、２時間の条件で合成した。更に、水を加えて固形分濃度約３重量％の原料スラリーとし、６ｍｍの厚さに抄造した。なお、本例においては、凝結遅延剤として酒石酸を使用した。
次に、湿空雰囲気中、３０℃で８時間にわたり１次養生を行った後、圧力容器中、飽和水蒸気下１８０℃、１０時間の条件で水熱反応を行った。
表１に水熱反応後の嵩比重、曲げ強度並びに層間剥離強度(共に絶乾状態)を示す。
【００４９】
【表１】
実施例２
表２に示す割合で原料を配合し、１２倍の水で撹拌、混合した。なお、ゲルは消石灰１０重量％、珪藻土１０重量％(重量比１：１)を９０℃、２時間の条件で合成した。更に、水を加えて固形分濃度約３重量％の原料スラリーとした。また、１番目または最後の抄箱は、別に調製した固形分濃度１０重量％の半水石膏及び凝結遅延剤を含有してなるスラリーとし、６ｍｍの厚さに抄造した。なお、本例において、凝結遅延剤として酒石酸を使用した。
次に、湿空雰囲気中、３０℃で８時間の１次養生を行った後、圧力容器中、飽和水蒸気下１８０℃、１０時間の条件で水熱反応を行った。
表２に水熱反応後の嵩比重、曲げ強度並びに層間剥離強度(共に絶乾状態)を示す。
【００５１】
【表１】
実施例３
表３に示す割合で原料を配合し、１２倍の水で撹拌、混合した。なお、ゲルは消石灰１０重量％、珪藻土１０重量％(重量比１：１)を９０℃、２時間の条件で合成した。更に、水を加えて、固形分濃度約３重量％の原料スラリーとし、６ｍｍの厚さに抄造した。抄造にあたり、リターンロールとメーキングロールの間の抄造フィルム上に、表３に示す量の半水石膏を粉体として、あるいは半水石膏と凝結遅延剤とのスラリーとして散布した。散布スラリー濃度は、固形分濃度１０重量％とした。なお、本例において、凝結遅延剤としては酒石酸を使用した。
次に、湿空雰囲気中、３０℃で８時間の１次養生を行った後、圧力容器中、飽和水蒸気下１８０℃、１０時間の条件で水熱反応を行った。
表３に水熱反応後の嵩比重、曲げ強度並びに層間剥離強度(共に絶乾状態)を示す。
【００５３】
【表３】
実施例４
表４に示す割合で原料を配合し、１２倍の水で撹拌、混合した。なお、ゲルは消石灰１０重量％、珪藻土１０重量％(重量比１：１)を９０℃、２時間の条件で合成した。更に、水を加えて、固形分濃度約３重量％の原料スラリーとした。また、１番目の抄箱あるいは最後の抄箱も同様に配合、混合して固形分濃度約２重量％の原料スラリーとし、６ｍｍの厚さに抄造した。なお、本例において、凝結遅延剤として酒石酸を使用した。
次に、湿空雰囲気中、３０℃で８時間の１次養生を行った後、圧力容器中、飽和水蒸気下で１８０℃、１０時間の条件で水熱反応を行った。
表４に水熱反応後の嵩比重、曲げ強度並びに層間剥離強度(共に絶乾状態)を示す。
【００５５】
【表４】
【発明の効果】
以上のように、本発明の珪酸カルシウム板の製造方法を用い、原料スラリーを抄造法により成形すれば、水熱反応前の成形体の強度及び層間強度を向上することができ、それによって水熱反応中の成形体の剥離、パンクを防止すると共に、得られる珪酸カルシウム板の層間剥離強度を向上させることができるという効果を奏するものである。
【図面の簡単な説明】
【図１】本発明の第３発明に使用可能な丸網式抄造機の一例を示す図である。
【符号の説明】
１ メーキングロール
２ リターンロール
３ フェルト
４ 抄造フィルム
５ 散布装置
６ 抄箱
７ 原料スラリー
８ 丸網シリンダー[0001]
[Industrial application fields]
The present invention relates to calcium silicate Plank Regarding the manufacturing method, more specifically, lightweight (for example, bulk specific gravity of 1.0 or less) calcium silicate Plank It relates to a manufacturing method.
[0002]
[Conventional technologies and issues]
Conventionally, calcium silicate plates are lightweight, have excellent workability and dimensional stability, and are non-flammable, and are widely used mainly as interior materials for interiors. As a forming method of such a calcium silicate plate, a papermaking method, a press mold method, a single layer forming method, etc. are utilized, and a formed body formed from a raw material slurry containing a calcareous raw material, a siliceous raw material, and an inorganic filler. In general, a calcium silicate plate is produced by reaction hardening with saturated steam in a pressure vessel.
[0003]
However, especially in the papermaking method, when manufacturing a lightweight calcium silicate plate, the interlaminar strength of the molded body before the hydrothermal reaction is weak and the water content is high, so the thermal expansion of excess water during the hydrothermal reaction. May occur, the vapor pressure may increase, and problems such as delamination and puncture may occur.
[0004]
In order to prevent these problems, a method of performing pressing after molding and then performing a hydrothermal reaction or tightening with a turnbuckle during the hydrothermal reaction is performed, but when these methods are taken There were drawbacks such as high bulk specific gravity and man-hours for production.
[0005]
In addition, 6 Although there is a method for removing excess water as disclosed in Japanese Patent No. -287083, it is not a general method because it requires a special container or a steam superheater.
[0006]
Furthermore, the present inventors have already disclosed in Japanese Patent Application No. 6-323225 and Japanese Patent Application No. 7-5013 an amorphous silicic acid raw material and a silicate raw material which have good reactivity with a calcareous raw material as part of the siliceous raw material. Or a method of adding a curing agent such as Portland cement or granulated blast furnace slag has been proposed, but there are drawbacks such as using expensive raw materials and increasing the bulk specific gravity.
[0007]
Therefore, the object of the present invention is to form a green body (green sheet) before hydrothermal reaction by using hemihydrate gypsum without adding a curing agent such as amorphous silicate raw material, silicate raw material, Portland cement or granulated blast furnace slag. ) Strength and interlayer strength are improved, and a lightweight calcium silicate board is produced that does not cause delamination or puncture during hydrothermal reaction. The law It is to provide.
[0008]
[Means for Solving the Problems]
That is, the present invention is a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In the manufacturing method of a calcium silicate board which consists of making the molded object obtained by laminating | stacking by a papermaking method hydrothermally react in a pressure vessel, a raw material slurry is 5 to 40 weight% and a half as a solid content of a semihydrate gypsum. It contains 0.05 to 0.5% by weight of a setting retarder on an external basis with respect to hydrated gypsum. The molded body obtained by papermaking is primarily cured to hydrate the hydrated gypsum. In addition, the present invention relates to a method for producing a lightweight calcium silicate plate characterized by performing a hydrothermal reaction.
[0009]
The present invention also provides a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In a method for producing a calcium silicate plate, which is obtained by laminating a molded body obtained by laminating by a papermaking method in a pressure vessel, the slurry put in the first and last boxmaking box of a round netting machine At least one of them contains a setting retarder of 5 to 40% by weight of hemihydrate gypsum as a solid content and 0.05 to 0.5% by weight of an outer percentage of hemihydrate gypsum, and is obtained by papermaking. It relates to a method for producing a lightweight calcium silicate plate characterized in that hemihydrate gypsum is hydrated by primary curing of the molded body and then hydrothermal reaction is performed.
[0010]
Furthermore, the present invention provides a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In a method for producing a calcium silicate plate, which is obtained by laminating a molded product obtained by laminating by a papermaking method in a pressure vessel, on a papermaking film between a return roll and a making roll of a papermaking machine, 10-50 g / m of water gypsum powder 2 Laminate while spraying at a ratio of predetermined thickness In After lamination, the composition obtained by papermaking Form It relates to a method for producing a lightweight calcium silicate plate characterized in that hemihydrate gypsum is hydrated by primary curing and then hydrothermal reaction is performed.
[0011]
The present invention also provides a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In a method for producing a calcium silicate plate, which is obtained by laminating a formed body obtained by laminating by a papermaking method in a pressure vessel, a solid is formed on the papermaking film between the return roll and the making roll of the papermaking machine. As a fraction, a slurry containing 0.05 to 0.5% by weight of a setting retarder in an external ratio with respect to hemihydrate gypsum and hemihydrate gypsum is 10 to 50 g / m in terms of hemihydrate gypsum solid content. 2 It is characterized by laminating while spraying at a ratio of 5% and laminating to a predetermined thickness, then hydrating the hemihydrate gypsum by first curing the molded body obtained by papermaking, and then performing a hydrothermal reaction It relates to a method for producing a lightweight calcium silicate plate.
[0012]
Furthermore, the present invention provides a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In a method for producing a calcium silicate plate, which is obtained by laminating a molded body obtained by laminating by a papermaking method in a pressure vessel, the slurry put in the first and last boxmaking box of a round netting machine Either one of them contains 92 to 98% by weight of hemihydrate gypsum as a solid content, 2 to 8% by weight of a fiber raw material, and 0.05 to 0.5% by weight of a setting retarder on the basis of hemihydrate gypsum. By making the papermaking thickness of the slurry 1 to 10% of the total papermaking thickness produced while the felt of the round net type papermaking machine makes a round, and primarily curing the molded body obtained by papermaking Hydrate hemihydrate gypsum, then hydrothermal reaction Preparative according to the method of manufacturing a lightweight calcium silicate board according to claim.
[0013]
The present invention also provides a raw material slurry containing 17-50% by weight of a calcareous raw material, 15-45% by weight of a siliceous raw material, 2-8% by weight of a fibrous raw material, and 5-30% by weight of an inorganic filler. In a method for producing a calcium silicate plate, which is obtained by laminating a molded body obtained by laminating by a papermaking method in a pressure vessel, the slurry put in the first and last boxmaking box of a round netting machine Either one of them as solid content exceeds 40% by weight and less than 98% by weight, fibrous raw material 2 to 8% by weight, calcareous raw material and inorganic filling Material 1 or 2 or more components selected from the group consisting of 58% by weight or less, and 0.05 to 0.5% by weight of a setting retarder on the basis of hemihydrate gypsum, Hydrated gypsum is hydrated by primary curing of the molded body obtained by papermaking, with the papermaking thickness of the slurry set to 1 to 10% of the total papermaking thickness that is made while the felt of the round net papermaking machine makes a round. Next, it relates to a method for producing a lightweight calcium silicate plate characterized by performing a hydrothermal reaction.
[0015]
[Action]
Of the present invention lightweight Calcium silicate plate (Hereinafter simply referred to as “calcium silicate plate”) The basic composition of the raw material slurry used in the production method is as follows: calcined raw material 17 to 50% by weight, silicic acid raw material 15 to 45% by weight, fibrous raw material 2 to 8% by weight and inorganic filler 5 to 30% by weight % Is a conventional one.
[0016]
Here, as the calcareous raw material, for example, slaked lime, quick lime and the like can be used. In addition, when the compounding quantity of a calcareous raw material is less than 17 weight% or exceeds 50 weight%, since bending strength is low and the dimensional change rate by water absorption becomes large, it is not preferable.
[0017]
Moreover, as a siliceous raw material, for example, silica sand, diatomaceous earth, fly ash and the like can be used. In addition, when the compounding quantity of a silicon raw material is less than 15 weight% or exceeds 45 weight%, since bending strength is low and the dimensional change rate by water absorption becomes large, it is unpreferable.
[0018]
Moreover, about a calcareous raw material and a siliceous raw material, 2-20 weight% of calcareous raw materials and 3-25 weight% of siliceous raw materials can be previously gelatinized and used among the said ratios. Examples of gelling conditions include 1.5 to 4 hours at a temperature of 75 to 90 ° C.
[0019]
Furthermore, as the fiber material, for example, cellulose fiber, polypropylene, vinylon, glass fiber, carbon fiber and the like can be used. In addition, it is not preferable that the blending amount of the fibrous raw material is less than 2% by weight because the bending strength is low, and if it exceeds 8% by weight, it is not preferable because it is not incombustible. Moreover, when using polypropylene, vinylon, glass fiber, carbon fiber, etc., it is preferable that those compounding quantities shall be 5 weight% or less.
[0020]
Further, as the inorganic filler, for example, pearlite, wollastonite, mica, talc, calcium carbonate, dihydrate gypsum and the like can be used. In addition, it is not preferable that the blending amount of the inorganic filler is less than 5% by weight because the dimensional change rate due to water absorption increases, and if it exceeds 30% by weight, the bending strength decreases, which is not preferable.
[0021]
The feature of this invention is the following six methods as a manufacturing method of a calcium silicate board:
According to the manufacturing method according to the first aspect of the present invention, the raw slurry having the above-described component blend is 5 to 40% by weight of hemihydrate gypsum and 0.05 to 0.5 in an external ratio with respect to the hemihydrate gypsum. This raw material slurry is laminated by a paper making method and molded by adding a weight% setting retarder, and then the resulting molded body is primarily cured to hydrate the hemihydrate gypsum and then hydrothermally. By performing the reaction, a calcium silicate plate can be produced.
[0022]
That is, the raw material slurry used in the first invention is, as a solid content, 17-50% by weight of calcareous raw material, 15-45% by weight of siliceous raw material, 2-8% by weight of fibrous raw material, 5-40% by weight of hemihydrate gypsum, It contains an inorganic filler 5 to 30% by weight, and 0.05 to 0.5% by weight of a setting retarder in an outer ratio with respect to hemihydrate gypsum. Here, if the blending amount of hemihydrate gypsum is less than 5% by weight, it is not preferable because of the poor expression of the interlayer strength of the green sheet. This is not preferable because the raw material cost is increased and the bending strength is lowered. The amount of hemihydrate gypsum is preferably 10 to 35% by weight.
[0023]
When hemihydrate gypsum is used in a slurry state, the hydration rate is very fast, and therefore it is essential to add a setting retarder to the raw material slurry. Here, if the blending amount of the setting retarder is less than 0.05% by weight relative to the hemihydrate gypsum, the setting retarding effect cannot be exhibited and hydration is completed before the raw material slurry is made. This is not preferable because it does not contribute to the development of the interlayer strength of the green sheet. If the blending amount of the setting retarder exceeds 0.5% by weight, it is necessary to hydrate the hemihydrate gypsum in the molded article after papermaking. It is not preferable because it takes a very long time for the primary curing, and sufficient hydration cannot be performed, and the strength of the molded product becomes weak. That is, by adding 0.05 to 0.5% by weight of a setting retarder to hemihydrate gypsum, the hydration reaction of hemihydrate gypsum can be delayed for about 10 to 20 hours after slurry preparation. If the production of the green sheet is completed within about 6 to 15 hours after slurry preparation, the effect of the present invention can be obtained.
[0024]
Next, according to the manufacturing method according to the second invention of the present invention, the first and last papermaking of the round net type papermaking machine is carried out by laminating and forming the raw material slurry having the above-described component blending by the papermaking method. At least one of the slurries put in the box contains 5-40% by weight of hemihydrate gypsum as a solid content and 0.05-0.5% by weight of a setting retarder in an external ratio with respect to hemihydrate gypsum, A calcium silicate board can be manufactured by hydrating hemihydrate gypsum by first curing the molded body obtained by papermaking and then performing a hydrothermal reaction.
[0025]
That is, in the second invention, a slurry having the same composition as that of the raw material slurry used in the first invention is used as a slurry for the first and / or last box making box of the round net type machine. Here, if the amount of hemihydrate gypsum in the slurry used for the first and / or last box is less than 5% by weight as the solid content, it is not preferable because the interlayer strength of the green sheet is poor. On the other hand, if it exceeds 40% by weight, the amount of the setting retarder used is increased, the raw material cost is increased, and the bending strength is lowered.
[0026]
When hemihydrate gypsum is used in a slurry state, the hydration rate is very fast, so it is essential to add a setting retarder to the slurry. If the blending amount of the setting retarder is less than 0.05% by weight with respect to the hemihydrate gypsum, the setting retarding effect cannot be exhibited, and the hydration is completed before the slurry is made. This is not preferable because it does not contribute to the development of the interlayer strength of the glass, and when the blending amount of the setting retarder exceeds 0.5% by weight, the primary curing for hydrating the hemihydrate gypsum in the molded body after papermaking This is not preferable because it takes a very long time, and sufficient hydration cannot be performed, and the strength of the molded product becomes weak.
[0027]
According to the second invention of the present invention, a slurry obtained by further adding hemihydrate gypsum and a setting retarder to the raw material slurry of the basic composition is put into the first and / or the last box of the round net type machine, Laminate and form by paper making method. The method of putting this slurry into the first and / or last paper box is not particularly limited. For example, a slurry having a blending ratio different from that of other paper boxes is prepared and sent from a dedicated chest. Alternatively, the slurry of hemihydrate gypsum and the setting retarder may be added to other slurries between the chest and the box.
[0028]
Next, according to the manufacturing method according to the third aspect of the present invention, when the raw material slurry having the basic composition as described above is laminated and formed by the papermaking method, the papermaking between the return roll and the making roll of the papermaking machine. 10-50 g / m of hemihydrate gypsum powder on the film 2 After spraying at a ratio of 5% and laminating to a predetermined thickness, the resulting molded body is primarily cured to hydrate the hemihydrate gypsum, and then hydrothermally reacted to produce a calcium silicate plate. Can be manufactured.
[0029]
Here, the application amount of hemihydrate gypsum powder is 10 g / m 2 Is not preferable because the strength of the interlayer strength is poor, and the application amount of the hemihydrate gypsum powder is 50 g / m. 2 If it exceeds 1, a layer of hemihydrate gypsum is formed, cracking occurs during drying, and bending strength is lowered, which is not preferable.
[0030]
An example of a round net-type paper machine that can be used in the third invention of the present invention is shown in FIG. According to this round net-making machine, the slurry (7) is rolled up by the round net cylinder (8) provided in the paper box (6) and transferred to the felt (3). A green sheet is obtained by repeating the number of mesh cylinders) to make a papermaking film (4), and further winding the papermaking film (4) to a predetermined thickness with a making roll (1) and then cutting. Can do. In general, delamination and puncture occur between films laminated by a making roll (1) .Therefore, a spraying device (5) is installed between the return roll (2) and the making roll (1). By spreading the body, delamination and puncture can be prevented by improving the adhesion (interlayer strength) between the films.
[0031]
Next, according to the manufacturing method according to the fourth aspect of the present invention, when the raw material slurry having the basic composition as described above is laminated and formed by the papermaking method, the papermaking between the return roll and the making roll of the papermaking machine. A slurry for spraying containing 0.05 to 0.5% by weight of a setting retarder on the basis of a half-water gypsum and a half-water gypsum on a film is 10 to 50 g in terms of a half-water gypsum solid content. / M 2 After being layered while spraying at a ratio of 5% to a predetermined thickness, the molded body obtained by papermaking is primarily cured to hydrate the hemihydrate gypsum, and then hydrothermally react to produce silicic acid. A calcium plate can be manufactured.
[0032]
The application amount of the slurry for application is 10 g / cm in terms of the amount of semi-hydrate gypsum solid content. 2 Less than is not preferable because the interlayer strength is poor, and the application amount of the slurry is 50 g / cm in terms of the amount of hemihydrate gypsum solid content. 2 If it exceeds 1, a layer of hemihydrate gypsum is formed, cracking occurs during drying, and bending strength is lowered, which is not preferable. Here, although the solid content concentration of the slurry for spraying is not particularly limited, it is usually 5 to 20% by weight, preferably about 8 to 15% by weight, and is more than the solid content concentration of the slurry generally used for papermaking. Those having a slightly higher solid content are preferred.
[0033]
In addition, when spraying hemihydrate gypsum with a slurry for spraying, it is essential to add a setting retarder to the slurry for spraying because hemihydrate gypsum has a very fast hydration rate. If the blending amount of the setting retarder is less than 0.05% by weight with respect to the hemihydrate gypsum, the setting retarding effect cannot be exhibited, and the hydration is completed before the slurry is made. This is not preferable because it does not contribute to the development of the interlayer strength of the glass, and when the blending amount of the setting retarder exceeds 0.5% by weight, the primary curing for hydrating the hemihydrate gypsum in the molded body after papermaking This is not preferable because it takes a very long time, and sufficient hydration cannot be performed, and the strength of the molded product becomes weak.
[0034]
Next, according to the manufacturing method according to the fifth aspect of the present invention, in forming and laminating the raw material slurry having the above basic composition by the papermaking method, the first and last papermaking of the round net type papermaking machine. Either one of the slurries in the box is 92 to 98 wt% hemihydrate gypsum in terms of solid content, 2 to 8 wt% fiber raw material, and 0.05 to 0.5 excluding the amount of hemihydrate gypsum. It contains 1% by weight of a set retarder, and the thickness of the paper made by the slurry is 1 to 10%, preferably 1 to 5% of the total paper thickness that is made while the felt of the round net paper making machine goes around. A calcium silicate board can be manufactured by hydrating hemihydrate gypsum after shaping | molding and then performing a hydrothermal reaction.
[0035]
Here, if the papermaking thickness by the slurry is less than 1%, it is not preferable because peeling between the sheets tends to occur due to poor expression of interlayer strength. In addition, when using a slurry having a high content of hemihydrate gypsum of 92 to 98% by weight, if the papermaking thickness exceeds 10%, the layer of hemihydrate gypsum becomes thick and the bending strength after hydrothermal reaction is increased. Is unfavorable because of lowering.
[0036]
Moreover, as a fiber raw material, a cellulose fiber etc. can be used. In addition, it is not preferable that the blending ratio of hemihydrate gypsum exceeds 98% by weight because the blending ratio of the fibrous raw material is reduced and the powder loss is increased during papermaking. Further, if the blending ratio of the fibrous raw material exceeds 8% by weight, it is not preferable because a fibrous raw material layer can be formed and easily peeled off.
[0037]
When hemihydrate gypsum is used in a slurry state, it is essential to add a setting retarder to the slurry because hemihydrate gypsum has a very fast hydration rate. If the setting retarder is less than 0.05% by weight with respect to hemihydrate gypsum, the setting retarding effect cannot be expressed, and hydration is completed before the slurry is made, which leads to the development of interlayer strength of the green sheet. It is not preferable because it does not contribute, and if the amount of the setting retarder exceeds 0.5% by weight, it takes a very long time for the primary curing to hydrate the hemihydrate gypsum in the molded body after papermaking. This is not preferable because sufficient hydration cannot be performed and the strength of the molded article is weakened.
[0038]
When hemihydrate gypsum is used in a slurry state, the concentration of this slurry is preferably the same as or lower than the concentration of the raw material slurry of other box making boxes, preferably 1 to 10% in solid content concentration, preferably It is preferable to set it as 3 to 7%. However, if it is necessary to lower the slurry water level in the box or change the cylinder mesh to an appropriate size in order to adjust the amount of slurry solids on the round net as much as possible. There is also.
[0039]
Next, according to the manufacturing method according to the sixth aspect of the present invention, when the raw slurry having the above basic composition is laminated and formed by the papermaking method, the first and last papermaking of the round net type papermaking machine. One selected from the group consisting of hemihydrate gypsum more than 40 wt% and less than 98 wt%, fibrous raw material 2 to 8 wt%, calcareous raw material, and inorganic filler as one of the slurries put in the box Or it contains 58% by weight or less of two or more components, and 0.05 to 0.5% by weight of a setting retarder on the basis of hemihydrate gypsum. 1 to 10%, preferably 1 to 5% of the total thickness of the paper made while the felt of the paper making machine goes around, and hydrate the hemihydrate gypsum by first curing the molded body obtained by paper making Then, the calcium silicate by hydrothermal reaction It can be produced.
[0040]
If the paper making thickness by the slurry is less than 1%, the interlayer strength is poorly developed, and peeling is likely to occur, which is not preferable. In addition, even when using a slurry having a relatively high content of hemihydrate gypsum exceeding 40% by weight and less than 98% by weight, if the papermaking thickness exceeds 10%, the layer of hemihydrate gypsum becomes thicker, This is not preferable because the bending strength after thermal reaction tends to decrease.
[0041]
Cellulose fibers and the like can be used as the fiber raw material. As the calcareous raw material, for example, slaked lime, quick lime and the like can be used. Furthermore, as the inorganic filler, for example, pearlite, wollastonite, mica, talc, calcium carbonate, silica sand, dihydrate gypsum and the like can be used. By blending one or more selected from the group consisting of the calcareous raw material and the inorganic filler, the raw material cost of the calcium silicate plate can be reduced while maintaining the interlayer strength. When the blending ratio of hemihydrate gypsum exceeds 98% by weight, the blending ratio of the fibrous raw material decreases and the loss of powder increases, which is not preferable, and when the blending ratio of hemihydrate gypsum is 40% by weight or less In the case where hemihydrate gypsum is blended with only one of the first and last slurries of the round net-making machine, it is not preferable because the blending effect does not appear remarkably. When the blending ratio of the fibrous raw material exceeds 8% by weight, it is not preferable because a fibrous raw material layer is formed and is easily peeled off. Furthermore, when the blending ratio of the calcareous raw material and / or the inorganic filler exceeds 58% by weight, it is not preferable because hemihydrate gypsum and the fibrous raw material cannot be blended sufficiently.
[0042]
When hemihydrate gypsum is used in a slurry state, it is essential to add a setting retarder to the slurry because hemihydrate gypsum has a very fast hydration rate. If the setting retarder is less than 0.05% by weight with respect to hemihydrate gypsum, the setting retarding effect cannot be expressed, and hydration is completed before the slurry is made, which leads to the development of interlayer strength of the green sheet. It is not preferable because it does not contribute, and if the amount of the setting retarder exceeds 0.5% by weight, it takes a very long time for the primary curing to hydrate the hemihydrate gypsum in the molded body after papermaking. This is not preferable because sufficient hydration cannot be performed and the strength of the molded article is weakened.
[0043]
The concentration of the slurry is preferably the same as or lower than the concentration of the raw material slurry of the other paper box, and is preferably 1 to 10%, preferably 3 to 7% in terms of solid content. However, if it is necessary to lower the slurry water level in the box or change the cylinder mesh to an appropriate size in order to adjust the amount of slurry solids on the round net as much as possible. There is also.
[0044]
The setting retarder used in the present invention is not particularly limited, and glycerin, alcohol, phosphate, carboxylic acid, oxycarboxylic acid or salts thereof, amino acid derivatives, and the like can be used.
[0045]
The molded body obtained by papermaking undergoes a hydrothermal reaction after a hydration reaction of hemihydrate gypsum by primary curing. The conditions for the primary curing are not particularly limited, and can be carried out under conventional conditions in which hemihydrate gypsum hydrates, preferably at 20 to 60 ° C. for 3 hours or more.
[0046]
The molded body after the primary curing as described above can be hydrated under conventional hydrothermal reaction conditions, and can be made into a calcium silicate plate through the subsequent conventional steps. The hydrothermal reaction can be carried out in a pressure vessel under a saturated water vapor pressure at a temperature of 150 to 200 ° C., preferably 170 to 190 ° C. for 5 to 20 hours, preferably 8 to 12 hours.
[0047]
The calcium silicate plate manufactured by the manufacturing method according to the first to sixth inventions of the present invention as described above exhibits a very excellent value with a delamination strength of 3% or more of a bending strength (an absolutely dry state). It will be a thing. The bending strength is a result of testing with a No. 3 test piece in accordance with JIS A 5418, and the delamination strength test is a result of being performed at 30 × 30 mm.
[0048]
【Example】
Example 1
The raw materials were blended at the ratio shown in Table 1, and stirred and mixed with 12 times the amount of water. The gel was synthesized with 10% by weight of slaked lime and 10% by weight of diatomaceous earth (weight ratio 1: 1) at 90 ° C. for 2 hours. Further, water was added to obtain a raw material slurry having a solid content concentration of about 3% by weight, and the paper was made into a thickness of 6 mm. In this example, tartaric acid was used as a setting retarder.
Next, after performing primary curing at 30 ° C. for 8 hours in a humid air atmosphere, hydrothermal reaction was performed in a pressure vessel under saturated steam at 180 ° C. for 10 hours.
Table 1 shows the bulk specific gravity, bending strength and delamination strength (both in an absolutely dry state) after the hydrothermal reaction.
[0049]
[Table 1]
Example 2
The raw materials were blended in the proportions shown in Table 2, and stirred and mixed with 12 times the water. The gel was synthesized with 10% by weight of slaked lime and 10% by weight of diatomaceous earth (weight ratio 1: 1) at 90 ° C. for 2 hours. Further, water was added to obtain a raw material slurry having a solid concentration of about 3% by weight. The first or last box was made into a slurry containing a semi-hydrated gypsum having a solid content concentration of 10% by weight and a setting retarder, and made into a thickness of 6 mm. In this example, tartaric acid was used as a setting retarder.
Next, after performing primary curing at 30 ° C. for 8 hours in a humid air atmosphere, hydrothermal reaction was performed in a pressure vessel under saturated steam at 180 ° C. for 10 hours.
Table 2 shows the bulk specific gravity, bending strength and delamination strength (both in an absolutely dry state) after the hydrothermal reaction.
[0051]
[Table 1]
Example 3
The raw materials were blended in the proportions shown in Table 3, and stirred and mixed with 12 times the water. The gel was synthesized with 10% by weight of slaked lime and 10% by weight of diatomaceous earth (weight ratio 1: 1) at 90 ° C. for 2 hours. Further, water was added to form a raw material slurry having a solid content concentration of about 3% by weight, and the paper was made into a thickness of 6 mm. In papermaking, the amount of hemihydrate gypsum shown in Table 3 was sprayed as a powder or a slurry of hemihydrate gypsum and a setting retarder on the papermaking film between the return roll and the making roll. The spray slurry concentration was set to a solid content concentration of 10% by weight. In this example, tartaric acid was used as the setting retarder.
Next, after performing primary curing at 30 ° C. for 8 hours in a humid air atmosphere, hydrothermal reaction was performed in a pressure vessel under saturated steam at 180 ° C. for 10 hours.
Table 3 shows the bulk specific gravity, bending strength and delamination strength (both in an absolutely dry state) after the hydrothermal reaction.
[0053]
[Table 3]
Example 4
The raw materials were blended in the proportions shown in Table 4, and stirred and mixed with 12 times the water. The gel was synthesized with 10% by weight of slaked lime and 10% by weight of diatomaceous earth (weight ratio 1: 1) at 90 ° C. for 2 hours. Furthermore, water was added to obtain a raw material slurry having a solid concentration of about 3% by weight. In addition, the first box or the last box was blended and mixed in the same manner to obtain a raw material slurry having a solid content concentration of about 2% by weight, and was made into a thickness of 6 mm. In this example, tartaric acid was used as a setting retarder.
Next, after performing primary curing at 30 ° C. for 8 hours in a humid air atmosphere, hydrothermal reaction was performed in a pressure vessel under saturated steam at 180 ° C. for 10 hours.
Table 4 shows the bulk specific gravity, bending strength and delamination strength (both in an absolutely dry state) after the hydrothermal reaction.
[0055]
[Table 4]
【The invention's effect】
As described above, if the raw material slurry is formed by a papermaking method using the method for producing a calcium silicate plate of the present invention, the strength and interlayer strength of the molded body before the hydrothermal reaction can be improved, and thereby hydrothermal While preventing peeling and puncture of the molded body during the reaction, there are effects that the delamination strength of the obtained calcium silicate plate can be improved.
[Brief description of the drawings]
FIG. 1 is a view showing an example of a round net-type paper machine usable in the third invention of the present invention.
[Explanation of symbols]
1 Making roll
2 Return roll
3 Felt
4 Papermaking film
5 Spraying equipment
6 Paper box
7 Raw material slurry
8 Round net cylinder
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| JP13804095A JP3783736B2 (en) | 1995-06-05 | 1995-06-05 | Calcium silicate plate manufacturing method |
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| JP13804095A JP3783736B2 (en) | 1995-06-05 | 1995-06-05 | Calcium silicate plate manufacturing method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3719546B2 (en) * | 1996-04-22 | 2005-11-24 | 株式会社エーアンドエーマテリアル | Calcium silicate plate and method for producing the same |
| CN1254352C (en) * | 2001-03-02 | 2006-05-03 | 詹姆士·哈代国际金融公司 | Method and apparatus for forming laminated sheet material by spattering |
-
1995
- 1995-06-05 JP JP13804095A patent/JP3783736B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08333179A (en) | 1996-12-17 |
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