【発明の詳細な説明】[Detailed description of the invention]
（産業上の利用分野）
本発明は吸音材、透水材等に用いられる軽量
性、耐熱性、耐候性、耐水性に優れ、大きい機械
的強度を有する無機質軽量多孔体に関するもので
ある。
（従来の技術）
従来から、軽量骨材、パーライト等の無機質軽
量粒子をセメントや燐酸塩系、珪酸塩系の無機接
着剤あるいはポリエステル系、エポキシ系等の有
機接着剤で結合した軽量多孔体が種々開発され、
内外装用の吸音材や透水材等に用いられている。
（例えば、内田安三編「遮断材料総覧」、（昭
53.11.15）、産業技術センター、P.653〜654）しか
し、従来の無機質軽量多孔体のうち接着剤として
セメントを用いたものは機械的強度が小さいうえ
にセメント自体の吸水性が大きいため吸水、凍結
により破壊する欠点があり、また、燐酸塩系、珪
酸塩系の無機接着剤を用いたものは接着剤が可溶
性であるため雨水、湿気等によつて硬化した接着
剤が溶出し、無機質軽量粒子が剥離したり全体が
崩壊する欠点があつた。更にまた有機接着剤を用
いたものは可燃性となつて防火上好ましくないう
え耐熱性や耐候性に劣る欠点があり、機械的強
度、耐熱性、耐候性、耐水性をすべて兼ね備えた
無機質軽量多孔体は開発されていなかつた。
（発明が解決しようとする問題点）
本発明が解決しようとするところは無機質軽量
粒子を主体とする無機質軽量多孔体の機械的強
度、耐熱性、耐候性、耐水性を向上させることで
ある。
（問題点を解決するための手段）
本発明は粒度が0.3〜５mm、単位容積重量が0.1
〜1.2Kg／の無機質軽量粒子100容量部と、該無
機質軽量粒子の平均粒度の40％以下の粒度を有し
該無機質軽量粒子の溶融温度よりも低く600℃以
上の溶融温度を持つ無機質細粒５〜30容量部とを
焼結してなる0.2〜1.3の嵩比重と30〜50％の空隙
率とを有するものである。
本発明において用いられる無機質軽量粒子は黒
曜石、松脂岩、真珠岩等の発泡粒状物、シリカ、
ガラス等の粒状物、フライアツシユや汚泥焼却灰
等を造粒焼成した粒状物、膨張頁岩、軽石等の軽
量骨剤等を粒度が0.3〜５mmとなるように調整し
たものであつて、その単位容積重量が0.1〜1.2
Kg／の範囲にあるものである。その組成や形状
は特に限定されるものではないが吸水率はなるべ
く小さいことが好ましい。また、本発明において
用いられる無機質細粒はSiO2、TiO2等の酸成分、
Al2O3、B2O3等の中性成分、K2O、Na2O、PbO
等の塩基成分等から成る黒曜石、松脂岩、真珠
岩、シラス等の天然ガラスまたはこれらの成分を
人工的に混合したガラスあるいは釉薬等であり、
その粒度が前記の無機質軽量粒子の平均粒度の40
％以下となるように粒度調整されたものである。
この無機質細粒の組成は特に限定されるものでは
ないがその溶融温度は600〜1200℃の範囲にあつ
て主体となる無機質軽量粒子の溶融温度よりも
100℃以上低温であることが好ましい。無機質細
粒は高温にて軟化溶融して結合剤として作用する
のものであり、得られた無機質軽量多孔体を着色
するためにCO、Ni、Mn等の着色剤を混入させ
ておいてもよい。ここで上記した各数値限定の理
由を説明すると、無機質軽量粒子の粒度を0.3〜
５mmとしたのは0.3mm以下の場合には得られた多
孔体の空隙率が小さくなつたり目詰りを生じて吸
音率や吸水率が低下し、逆に５mmを越すと空隙径
や空隙率が過大となつて吸音率が大きく低下する
ためである。次に、その単位容積重量を0.1〜1.2
Kg／としたのは0.1Kg／を下廻ると粒子強度
が低下して得られた多孔体の機械的強度が低下
し、逆に1.2Kg／を上廻ると重量が大となつて
軽量である利点が失われるためである。また、無
機質細粒の粒度を無機質軽量粒子の平均粒度の40
％以下としたのは、この値を越えたものが多量に
混入すると焼結時に多孔体の収縮が部分的に大き
くなつて亀裂を生じたり空隙を目詰りさせ、吸音
率や吸水率が低下するためである。更に、その溶
融温度を600℃以上としたのは得られた多孔体の
最高使用温度を600℃とすれば高温用消音装置や
建屋内装の吸音材として用いる場合に十分な耐熱
性、防火性が得られるためである。
上記のような無機質軽量粒子100容量部に対し
て無機質細粒５〜30容量部が速練機、Ｖ型ミキサ
ー等の混合機により均一に混合されるが、この際
に澱粉、デキストリンのような有機性の糊剤を添
加することにより成形性と生強度を高めることが
好ましい。これらの糊剤は予め40〜60％の水溶液
としたうえ３〜12容量部が添加される。このよう
に混合された材料は離型剤が塗布された金型の内
部に充填され、振動加圧成形、加圧成形等の方法
で成形された後、無機質細粒の溶融温度以上で無
機質軽量粒子の溶融温度以下の温度で焼結され
る。このとき糊剤は焼失し、無機質細粒は溶融し
て粒度の大きい無機質軽量粒子の表面を覆うとと
もに各粒子を相互に強固に連結し、連続孔を有す
る多孔体を形成する。なお、無機質細粒が５容量
部以下であると良好な結合が得られず機械的強度
が不足する傾向を示し、30容量部を越えると空隙
が目詰りして連続孔が得られず、吸音率や透水性
が低下する傾向を生ずる。このようにして得られ
た本発明の無機質軽量多孔体の嵩比重、空隙率は
無機質軽量粒子の単位容積重量、粒度、無機質細
粒との混合比、金型への充填密度、成形条件、焼
成条件等の調整により任意に調整できるものであ
るが、嵩比重は0.2〜1.3、空隙率は30〜50％とす
ることが必要である。嵩比重が0.2未満の場合に
は十分な機械的強度が得られず、1.3を越えると
重量が大となつて施工性が悪化し、軽量である利
点が失われるからである。また、空隙率が30％未
満であると全体が緻密になりすぎて吸音率や透水
性が低下し、50％を越えると音波の流れ抵抗が小
さくなりすぎて吸音率が低下する。嵩比重及び空
隙率が上記範囲にある本発明の無機質軽量多孔体
は吸音体、透水材として優れた特性を備えたもの
である。
更に、本発明においては無機質軽量多孔体の内
部または表面のいずれか一方または双方に無機質
繊維や金網等の補強材を結合させることにより全
体の機械的強度や表面硬さ、美観等を向上させる
とともに万一破損した場合の破片の飛散防止効果
を得ることができ、また、これらを表面に結合さ
せることにより無機質軽量多孔体の開孔率を調整
して吸音率や透水性の調整、改良を行うことがで
きる。補強材として用いられる無機質繊維は３〜
25mm程度のガラス繊維やシリカ繊維あるいはそれ
らをクロス状、マツト状に織つたものが好まし
く、単繊維の場合には無機質軽量粒子の嵩容量に
対して10〜50ｇ／程度を糊剤の混合時に添加し
ておくか、金型への充填時に添加する。この場
合、無機質繊維の表面に糊材の水溶液を付着さ
せ、あるいは前述の無機質細粒と同じかそれ以下
の溶融温度のガラス質の微粉末を付着させておけ
ば、補強材の結合はより強力なものとなる。ガラ
ス質の微粉末を付着させるには予め糊材の水溶液
を無機質繊維の表面に付着させた後に混合する
か、ガラス質の微粉末に水や解曜剤等を加えて泥
漿にしたものをスプレー掛けする等の方法により
行う。また、補強材としては前記したほか金網を
用いることもでき、この場合および無機質繊維の
クロス、マツトを用いる場合には混合物を金型へ
充填する際に適当な寸法に切断して混合物表面ま
たはその内部に装入する。このような補強材の表
面にもガラス質の微粉末を付着させてもよいが、
焼結時に軟化溶融する無機質繊維のクロスやマツ
トを用いる場合にはガラス質の微粉末の付着量は
少なくすることが好ましい。補強材は焼成時に無
機質細粒およびガラス質の微粉末の溶融物によつ
て無機質軽量粒子と強固に結合し補強効果を与え
るものであつて、補強材の軟化溶融の程度が少な
いもの程それ自身の強度特性の残存率が高いので
補強効果が大となる。この意味から金網を用いる
場合には焼成温度を低くすることが好ましく、溶
融温度の低い無機質細粒を用いる必要がある。
（作用）
以上に説明した本発明の無機質軽量多孔体は次
の実施例に示す特性値からも明らかなように、軽
量であるうえに機械的強度、耐熱性、耐候性、耐
水性に優れたものであり、吸音材、透水材として
好適なものである。
（実施例）
黒曜石、松脂岩、真珠岩等の発泡粒状物、シリ
カ粒状物、フライアツシユや汚泥焼却灰等を焼成
した粒状物、膨張頁岩等の軽量骨材の中から選択
された無機質軽量粒子100容量部に対し、ガラス
質の無機質細粒を５〜30容量部加え、更に糊剤と
して澱粉の水溶液を３〜12容量部加えて５分間混
合して第１表に示す各種の混合物を作成した。こ
れを離型油を塗布した50×50×２cmの平板金型に
入れてつつき棒で均一に充填し、上型を乗せて振
動加圧成形機で成形した。なお、補強材としてガ
ラスマツト、シリカガラスクロス、金網を用した
No.６、８、９のものはこれらの補強材を50×50cm
に切断し、シリカガラスクロス及び金網について
は0.125mm以下の粒度に粉砕されたガラス質の微
粉末を澱粉の水溶液によりその表面に付着させた
うえ金型内にセツトして成形した。成形品は約50
℃の乾燥室で24時間乾燥させた後、アルミナ粉末
を散布した炭化珪素板に乗せ第１表記載の温度で
焼結した。同様に第２表に示す本発明範囲外のNo.
17〜No.29のものを作成した。これらの各無機質軽
量多孔体及びその比較例の多孔体について嵩比
重、空隙率、曲げ強度を測定し、更にJIS A1405
「管内法による垂直入射吸音率測定法」に準拠し
て100〜2000Hzの吸音率を測定し、ピーク値と250
〜1000Hzの平均値を求めた。耐候性試験はJIS
A1415「プラスチツク建築材料の促進暴露試験方
法」に準拠し、凍結溶解試験は20℃の水中にテス
トピースを20時間浸漬した後−10℃の気中で12時
間凍結する操作を30回繰返す方法により試験し、
難燃性試験はJIS A1321「建築物の内装材料及び
工法の難燃性試験方法」に準拠して行い、これら
の試験結果を第１表、第２表に示した。これらの
測定値及び試験結果から明らかなように、No.１〜
No.16の実施例品はいずれも軽量で強度が大きく、
吸音性、耐候性、耐水性、耐熱性に優れたもので
ある。
(Field of Industrial Application) The present invention relates to a lightweight inorganic porous body that is used for sound absorbing materials, water permeable materials, etc. and has excellent lightness, heat resistance, weather resistance, water resistance, and high mechanical strength. (Prior art) Light porous materials have traditionally been produced by bonding lightweight inorganic particles such as lightweight aggregate and perlite with cement, phosphate-based or silicate-based inorganic adhesives, or polyester-based or epoxy-based organic adhesives. Various developments have been made,
It is used for interior and exterior sound absorbing materials and water permeable materials.
(For example, "Comprehensive list of blocking materials" edited by Yasuzo Uchida, (A.
53.11.15), Industrial Technology Center, pp. 653-654) However, among conventional inorganic lightweight porous materials, those using cement as an adhesive have low mechanical strength and the cement itself has high water absorption, so it is difficult to absorb water. However, since adhesives using phosphate-based or silicate-based inorganic adhesives are soluble, the hardened adhesive may be eluted by rainwater, moisture, etc., and the inorganic There were drawbacks such as the lightweight particles peeling off and the entire structure collapsing. Furthermore, those using organic adhesives are flammable, which is not desirable in terms of fire prevention, and they also have the disadvantage of poor heat resistance and weather resistance. The body was not developed. (Problems to be Solved by the Invention) The problem to be solved by the present invention is to improve the mechanical strength, heat resistance, weather resistance, and water resistance of an inorganic lightweight porous body mainly composed of inorganic lightweight particles. (Means for solving the problem) The present invention has a particle size of 0.3 to 5 mm and a unit weight of 0.1 mm.
100 parts by volume of lightweight inorganic particles of ~1.2Kg/inorganic fine particles having a particle size of 40% or less of the average particle size of the lightweight inorganic particles and a melting temperature of 600°C or higher, which is lower than the melting temperature of the lightweight inorganic particles. It has a bulk specific gravity of 0.2 to 1.3 and a porosity of 30 to 50%, obtained by sintering 5 to 30 parts by volume. The inorganic lightweight particles used in the present invention include foamed granules such as obsidian, pinestone, pearlite, silica,
Granular materials such as glass, granular materials obtained by granulating and firing fly ash, sludge incineration ash, etc., lightweight aggregates such as expanded shale and pumice, etc., adjusted to a particle size of 0.3 to 5 mm, and their unit volume. Weight 0.1~1.2
It is in the range of Kg/. Although its composition and shape are not particularly limited, it is preferable that its water absorption rate be as small as possible. In addition, the inorganic fine particles used in the present invention include acid components such as SiO 2 and TiO 2 ,
Neutral components such as Al 2 O 3 and B 2 O 3 , K 2 O, Na 2 O, PbO
Natural glass such as obsidian, pinestone, perlite, shirasu, etc., which consists of basic components such as obsidian, etc., or glass or glaze made by artificially mixing these components, etc.
The particle size is 40% of the average particle size of the above-mentioned lightweight inorganic particles.
% or less.
The composition of these inorganic fine particles is not particularly limited, but their melting temperature is in the range of 600 to 1200℃, which is higher than the melting temperature of the main inorganic lightweight particles.
The temperature is preferably 100°C or more. The inorganic fine particles soften and melt at high temperatures and act as a binder, and a coloring agent such as CO, Ni, or Mn may be mixed in to color the obtained lightweight inorganic porous material. . To explain the reason for each numerical limitation mentioned above, the particle size of the inorganic lightweight particles is 0.3~
The reason why the value is 5 mm is that if it is less than 0.3 mm, the porosity of the obtained porous body will become smaller or clogging will occur, resulting in a decrease in sound absorption rate and water absorption rate.On the other hand, if it exceeds 5 mm, the pore diameter and porosity will decrease. This is because if it becomes too large, the sound absorption coefficient will decrease significantly. Then, its unit volume weight is 0.1~1.2
The reason for Kg/ is that when it goes below 0.1Kg/, the particle strength decreases and the mechanical strength of the resulting porous body decreases, and on the other hand, when it goes above 1.2Kg/, the weight increases and it becomes lightweight. This is because the advantage will be lost. In addition, the particle size of the inorganic fine particles is 40% of the average particle size of the inorganic light particles.
% or less because if a large amount of material exceeding this value is mixed in, the porous material will partially shrink during sintering, causing cracks and clogging of voids, resulting in a decrease in sound absorption and water absorption. It's for a reason. Furthermore, the melting temperature was set at 600°C or higher because the obtained porous material has sufficient heat resistance and fire resistance when used as a high-temperature silencer or a sound absorbing material for building interiors if the maximum operating temperature is 600°C. This is because it can be obtained. 5 to 30 parts by volume of inorganic fine particles are uniformly mixed with 100 parts by volume of the above-mentioned lightweight inorganic particles using a mixer such as a speed kneader or a V-type mixer. It is preferable to improve moldability and green strength by adding an organic sizing agent. These glues are prepared in advance as a 40-60% aqueous solution and then added in an amount of 3-12 parts by volume. The material mixed in this way is filled into a mold coated with a mold release agent, and after being molded by vibration pressure molding, pressure molding, etc. Sintered at a temperature below the melting temperature of the particles. At this time, the paste is burned away, and the fine inorganic particles are melted and cover the surfaces of the large, lightweight inorganic particles, and the particles are firmly connected to each other, forming a porous body having continuous pores. If the amount of inorganic fine particles is less than 5 parts by volume, good bonding cannot be obtained and mechanical strength tends to be insufficient. If the amount exceeds 30 parts by volume, the voids become clogged and continuous pores cannot be obtained, resulting in poor sound absorption. This tends to cause a decrease in water permeability and water permeability. The bulk specific gravity and porosity of the inorganic lightweight porous body of the present invention obtained in this manner are determined by the unit volume weight of the inorganic lightweight particles, particle size, mixing ratio with inorganic fine particles, packing density in the mold, molding conditions, firing Although it can be adjusted arbitrarily by adjusting conditions, etc., it is necessary that the bulk specific gravity is 0.2 to 1.3 and the porosity is 30 to 50%. This is because if the bulk specific gravity is less than 0.2, sufficient mechanical strength cannot be obtained, and if it exceeds 1.3, the weight increases and workability deteriorates, and the advantage of being lightweight is lost. Furthermore, if the porosity is less than 30%, the entire material becomes too dense, resulting in a decrease in sound absorption coefficient and water permeability, and if it exceeds 50%, the flow resistance of sound waves becomes too small, resulting in a decrease in sound absorption coefficient. The inorganic lightweight porous material of the present invention having bulk specific gravity and porosity within the above ranges has excellent properties as a sound absorbing material and a water permeable material. Furthermore, in the present invention, reinforcing materials such as inorganic fibers and wire mesh are bonded to either the inside or the surface of the inorganic lightweight porous material, or both, thereby improving the overall mechanical strength, surface hardness, aesthetics, etc. It is possible to prevent fragments from scattering in the event of damage, and by bonding these to the surface, the porosity of the inorganic lightweight porous material can be adjusted to adjust and improve sound absorption coefficient and water permeability. be able to. The inorganic fibers used as reinforcing materials are 3~
Glass fibers or silica fibers of about 25 mm, or those woven into a cross or mat shape are preferable, and in the case of single fibers, add about 10 to 50 g per bulk volume of the inorganic lightweight particles when mixing the sizing agent. Either leave it aside or add it when filling the mold. In this case, if an aqueous glue solution is attached to the surface of the inorganic fibers, or a glassy fine powder with a melting temperature equal to or lower than that of the inorganic fine particles mentioned above is attached, the bond of the reinforcing material will be stronger. Become something. To attach vitreous fine powder, first attach an aqueous glue solution to the surface of the inorganic fibers and then mix it, or spray a slurry made by adding water or a desaturant to the vitreous fine powder. This is done by hanging or other methods. In addition to the above-mentioned reinforcing material, wire mesh can also be used. In this case, or when inorganic fiber cloth or mat is used, cut it into appropriate dimensions when filling the mixture into the mold to cover the surface of the mixture or Charge inside. Fine glass powder may be attached to the surface of such reinforcing material, but
When using an inorganic fiber cloth or mat that softens and melts during sintering, it is preferable to reduce the amount of vitreous fine powder attached. During firing, the reinforcing material is firmly bonded to the inorganic lightweight particles by the melted inorganic fine particles and glassy fine powder, and provides a reinforcing effect. Since the residual rate of strength characteristics is high, the reinforcing effect is large. In this sense, when using a wire mesh, it is preferable to lower the firing temperature, and it is necessary to use inorganic fine particles with a low melting temperature. (Function) As is clear from the characteristic values shown in the following examples, the inorganic lightweight porous material of the present invention described above is lightweight and has excellent mechanical strength, heat resistance, weather resistance, and water resistance. It is suitable as a sound absorbing material and a water permeable material. (Example) 100 inorganic lightweight particles selected from foamed granules such as obsidian, pinestone, pearlite, silica granules, granules obtained by burning fly ash, sludge incineration ash, etc., and lightweight aggregates such as expanded shale. Based on the volume, 5 to 30 parts by volume of vitreous inorganic fine particles were added, and 3 to 12 parts by volume of an aqueous starch solution was added as a sizing agent, and mixed for 5 minutes to prepare various mixtures shown in Table 1. . This was placed in a 50 x 50 x 2 cm flat plate mold coated with mold release oil, filled uniformly with a poking rod, placed on an upper mold, and molded using a vibration pressure molding machine. In addition, glass pine, silica glass cloth, and wire mesh were used as reinforcing materials.
For No. 6, 8, and 9, use these reinforcing materials 50 x 50 cm.
For silica glass cloth and wire mesh, fine glass powder pulverized to a particle size of 0.125 mm or less was adhered to the surface with an aqueous solution of starch, and then set in a mold and molded. Approximately 50 molded products
After drying for 24 hours in a drying chamber at ℃, it was placed on a silicon carbide plate sprinkled with alumina powder and sintered at the temperature listed in Table 1. Similarly, No. 2 outside the scope of the present invention shown in Table 2.
I created items No. 17 to No. 29. The bulk specific gravity, porosity, and bending strength of each of these inorganic lightweight porous bodies and their comparative porous bodies were measured, and further JIS A1405
The sound absorption coefficient of 100 to 2000 Hz was measured in accordance with the "normal incidence sound absorption coefficient measurement method using the in-pipe method", and the peak value and 250
The average value of ~1000Hz was determined. Weather resistance test is JIS
In accordance with A1415 "Accelerated Exposure Test Method for Plastic Building Materials", the freeze-thaw test is conducted by immersing the test piece in water at 20℃ for 20 hours and then freezing it in air at -10℃ for 12 hours, repeated 30 times. test,
The flame retardancy test was conducted in accordance with JIS A1321 "Flame retardant test method for building interior materials and construction methods", and the test results are shown in Tables 1 and 2. As is clear from these measurement values and test results, No. 1 to
All of the example products No. 16 are lightweight and have high strength.
It has excellent sound absorption, weather resistance, water resistance, and heat resistance.
【表】
※１ 両面にガラスマツト接着
※２ 内部にガラス短繊維混入 両面に金網接着
※３ 内部に金網埋込 両面にシリカガラスクロス接
着
※４ 両面にシリカガラスクロス接着
[Table] *1 Glass mat glued on both sides *2 Short glass fibers mixed inside Wire mesh glued on both sides *3 Wire mesh embedded inside Silica glass cloth glued on both sides *4 Silica glass cloth glued on both sides
【表】
（発明の効果）
本発明は以上の説明からも明らかなように、軽
量で機械的強度が大きく、耐熱性、耐候性、耐水
性に優れたものであるうえ大きい吸音率を備えた
ものであるから吸音体、透水材として好適なもの
であり、従来の無機質軽量多孔体の問題点を解消
したものとして産業の発展に寄与するところ極め
て大なものである。[Table] (Effects of the invention) As is clear from the above description, the present invention is lightweight, has high mechanical strength, has excellent heat resistance, weather resistance, and water resistance, and has a large sound absorption coefficient. Therefore, it is suitable as a sound-absorbing material and a water-permeable material, and it contributes greatly to the development of industry as it solves the problems of conventional inorganic lightweight porous materials.