JP2007099533A - Porous ceramic-made sound absorbing material - Google Patents
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本発明は、周波数１０００Ｈｚにおける吸音性能に優れる多孔質セラミックス製吸音材に関する。特に、高温下で使用される車両用のセラミックス製吸音材に関する。 The present invention relates to a sound absorbing material made of porous ceramics having excellent sound absorbing performance at a frequency of 1000 Hz. In particular, the present invention relates to a ceramic sound-absorbing material for vehicles used at high temperatures.
従来より使用されている代表的な耐熱性のある無機系吸音材には、グラスウールまたはロックルールなどの鉱物繊維系吸音材があるが、鉱物繊維系吸音材は、吸水しやすく、吸水すると吸音性能が低下し、また、繊維系吸音材であるため、経時変化を起こしやすく、容易に飛散し、剥離するなどの欠点がある。このため、鉱物繊維系吸音材を樹脂膜で覆い、または、金属製の筐体に収容して使用する必要があり、それだけ価格の高い吸音材となっている。 Typical heat-resistant inorganic sound-absorbing materials that have been used in the past include mineral fiber sound-absorbing materials such as glass wool or rock rule. Mineral fiber-based sound-absorbing materials are easy to absorb water and absorb sound when they absorb water. Further, since it is a fiber-based sound absorbing material, there is a drawback that it is likely to change with time, and is easily scattered and peeled off. For this reason, it is necessary to cover the mineral fiber-based sound absorbing material with a resin film, or to house and use it in a metal casing, which makes the sound absorbing material more expensive.
一方、多数の貫通孔を形成した石膏ボードも、吸音材として多用されているが、石膏ボード自体には吸音性能が無く、貫通孔における共鳴により消音する機構であるため、特定の周波数の音域しか吸音できないなどの欠点がある。このため、背面に空気層を形成し、または、グラスウールなどの鉱物繊維を背面に取付けて使用する必要があり、施工効率が悪い。また、ポリウレタンフォームのような有機系吸音材は、吸音性は良好であるが、耐熱性が劣る。 On the other hand, gypsum board with many through-holes is also widely used as a sound-absorbing material, but the gypsum board itself has no sound-absorbing performance and is a mechanism that silences by resonance in the through-holes. There are drawbacks such as inability to absorb sound. For this reason, it is necessary to form an air layer on the back surface or use a mineral fiber such as glass wool attached to the back surface, which is inferior in construction efficiency. Further, an organic sound absorbing material such as polyurethane foam has good sound absorbing properties but is inferior in heat resistance.
こうした中、珪酸塩を原料とし、焼成して得られるセラミックス製吸音材が開発され、使用されるようになっている。たとえば、粒径０．５０ｍｍ〜２．０ｍｍのパーライトと、フライアッシュなどの軽量骨材と、バインダーとを焼成して製造する多孔質セラミックス製吸音材が知られている（特許文献１参照）。パーライトは、真珠岩または松脂岩などの細砕物を１０００℃程度で焼成することにより、含有水分が蒸発し、そのガス圧により膨張した中空の球状体である。製造される多孔質セラミックス製吸音材は、嵩比重が０．５〜１．０であり、パーライト粒子同士が、接触部において連通し、内部気孔が連通しているため、低音領域から高音領域までの広い音域に亘り吸音特性が優れ、フライアッシュのような安価な原料を使用するため製品の製造コストが安いと同文献には記載されている。
しかし、このパーライトを原料とする多孔質セラミックス製吸音材は、無機系発泡剤を使用せず、フライアッシュなどの軽量骨材を用いているため、安定した気孔径が得られず、製品ごとに気孔径が大きくばらつき、安定した吸音性能が得られない。 However, the porous ceramic sound-absorbing material made of pearlite does not use inorganic foaming agents and uses lightweight aggregates such as fly ash, so a stable pore diameter cannot be obtained. The pore diameter varies greatly and stable sound absorption performance cannot be obtained.
本発明の課題は、耐熱性が優れるセラミックス製吸音材であって、安定した気孔径を有し、周波数１０００Ｈｚにおける吸音率が２０％以上の多孔質セラミックス製吸音材を提供することにある。 An object of the present invention is to provide a ceramic sound-absorbing material having excellent heat resistance, having a stable pore diameter, and having a sound absorption rate of 20% or more at a frequency of 1000 Hz.
本発明の多孔質セラミックス製吸音材は、珪酸塩を主原料とし、無機系発泡剤を０．０２質量％〜１．０質量％含有するセラミックス原料を焼成することにより製造され、ＪＩＳ−Ａ１４０５による周波数１０００Ｈｚにおける垂直入射吸音率が２０％以上であることを特徴とし、垂直入射吸音率が、周波数１０００±１００Ｈｚ帯域に極大ピークを有する態様が好ましい。 The sound absorbing material made of porous ceramics of the present invention is manufactured by firing a ceramic raw material containing silicate as a main raw material and containing 0.02% by mass to 1.0% by mass of an inorganic foaming agent, according to JIS-A1405. A normal incident sound absorption coefficient at a frequency of 1000 Hz is 20% or more, and an aspect in which the normal incident sound absorption coefficient has a maximum peak in a frequency band of 1000 ± 100 Hz is preferable.
アルキメデス法による比重が０．４〜１．０である多孔質セラミックス製吸音材が好ましく、気孔径が算術平均値で０．５ｍｍ〜１．３ｍｍである態様が好ましい。また、透水性が３．５ｇ／ｈ・ｃｍ2以上の吸音材が好適である。一方、無機系発泡剤としては、窒化珪素と炭化珪素と窒化アルミニウムとからなる群より選ばれる少なくとも１種が望ましい。また、セラミックス原料は、軽量骨材を１質量％〜４０質量％含有する態様が好ましい。本発明の吸音材は、高温下で使用する車両用部品、たとえば、エンジン周辺部品または二輪車のマフラー周辺部品として適する。 A sound absorbing material made of porous ceramics having a specific gravity by the Archimedes method of 0.4 to 1.0 is preferable, and an aspect in which the pore diameter is an arithmetic average value of 0.5 mm to 1.3 mm is preferable. A sound absorbing material having a water permeability of 3.5 g / h · cm 2 or more is suitable. On the other hand, the inorganic foaming agent is preferably at least one selected from the group consisting of silicon nitride, silicon carbide, and aluminum nitride. Moreover, the ceramic raw material preferably contains 1% by mass to 40% by mass of lightweight aggregate. The sound-absorbing material of the present invention is suitable as a vehicle part to be used at a high temperature, for example, an engine peripheral part or a motorcycle muffler peripheral part.
本発明の多孔質セラミックス製吸音材は、ばらつきの少ない気孔径を有し、周波数１０００Ｈｚにおける吸音率が２０％以上である。 The sound absorbing material made of porous ceramics of the present invention has a pore diameter with little variation, and has a sound absorption rate of 20% or more at a frequency of 1000 Hz.
本発明の多孔質セラミックス製吸音材は、珪酸塩を主原料として製造する。珪酸塩は、二酸化珪素と金属酸化物とからなる塩（ｘＭ2Ｏ・ｙＳｉＯ2）であり、金属（Ｍ）には、Ａｌ，Ｃａ，Ｍｇなどがある。主原料とは、セラミックス原料中に珪酸塩を、好ましくは５０質量％以上含有するものをいい、より好ましくは６０質量％以上含有するものをいう。珪酸塩は、天然物であれば、たとえば、安山岩または流紋岩などの珪酸塩鉱物から得ることができる。安山岩の組成は、ＳｉＯ2が６０質量％、Ａｌ2Ｏ3が１７質量％、ＣａＯが６質量％、Ｆｅ2Ｏ3が３質量％、ＦｅＯが３質量％、ＭｇＯが３質量％などであるものが多く、斜長石、角閃石および輝石などにより構成される火成岩である。また、流紋岩の組成は、ＳｉＯ2が７４質量％、Ａｌ2Ｏ3が１３質量％、Ｋ2Ｏが５質量％、Ｎａ2Ｏが３質量％、ＣａＯが１質量％、Ｆｅ2Ｏ3が１質量などであるものが多く、石英およびカリ長石などにより構成される火成岩である。一方、珪酸塩は、ガラスまたはスラグなどの人工物からも容易に得ることができる（以下、安山岩、流紋岩、ガラスなどを「珪酸塩含有物」ともいう。）。珪酸塩含有物は、耐久性、耐候性および耐酸性に優れる点で、軟化溶融点が９００℃〜１２５０℃のものが好ましく、軟化溶融点が１１００℃〜１２００℃の珪酸塩含有物がより好ましい。 The sound absorbing material made of porous ceramics of the present invention is manufactured using silicate as a main raw material. Silicate is a salt (xM 2 O · ySiO 2 ) composed of silicon dioxide and metal oxide, and metal (M) includes Al, Ca, Mg, and the like. The main raw material means a material containing 50 mass% or more of silicate in the ceramic raw material, and more preferably one containing 60 mass% or more. The silicate can be obtained from a silicate mineral such as andesite or rhyolite if it is a natural product. The composition of andesite, SiO 2 is 60 wt%, Al 2 O 3 is 17 wt%, CaO 6% by weight, Fe 2 O 3 is 3 wt%, FeO 3 mass%, MgO is like 3 wt% Many igneous rocks are composed of plagioclase, amphibole and pyroxene. The composition of rhyolite, SiO 2 is 74 wt%, Al 2 O 3 is 13 wt%, K 2 O 5 mass%, Na 2 O 3 mass%, CaO is 1 mass%, Fe 2 O 3 is a igneous rock composed of quartz, potassium feldspar, etc. On the other hand, silicates can be easily obtained from artificial materials such as glass or slag (hereinafter, andesite, rhyolite, glass, etc. are also referred to as “silicate-containing materials”). The silicate-containing material is preferably one having a softening melting point of 900 ° C. to 1250 ° C., more preferably a silicate-containing material having a softening melting point of 1100 ° C. to 1200 ° C. in terms of excellent durability, weather resistance and acid resistance. .
セラミックス原料には、珪酸塩含有物に加えて、無機系発泡剤を添加する。無機系発泡剤は、珪酸塩含有物が適度な粘性で溶融し、発泡を効率的に促進する点で、主原料である珪酸塩含有物の溶融温度より７００℃〜３０℃低い温度で気体を発生する無機系発泡剤が好ましく、珪酸塩の溶融温度より１００℃〜５０℃低い温度で気体を発生する無機系発泡剤がより好ましい。このような無機系発泡剤としては、生成する気孔径にばらつきが少なく、安定した吸音性能が得られる点で、炭化珪素、窒化珪素もしくは窒化アルミニウムまたはこれらの混合物が好適である。無機系発泡剤の添加量は、目的とする多孔質セラミックス製吸音材の比重、気孔径および透水性、焼成条件ならびに発泡剤の種類によって異なるが、通常、多孔質の成形体を形成し、吸音性能を高める観点から、無機系発泡剤は、セラミックス原料中に０．０２質量％以上添加し、０．０５質量％以上添加するのが好ましい。一方、吸音材の機械的強度を維持する点で、無機系発泡剤は、セラミックス原料中に１．０質量％以下の割合で添加し、０．５質量％以下がより好ましい。 In addition to the silicate-containing material, an inorganic foaming agent is added to the ceramic raw material. The inorganic foaming agent melts the silicate-containing material with an appropriate viscosity, and efficiently promotes foaming, so that the gas is generated at a temperature lower by 700 ° C. to 30 ° C. than the melting temperature of the silicate-containing material as the main raw material. An inorganic foaming agent that generates gas is preferable, and an inorganic foaming agent that generates gas at a temperature lower by 100 ° C. to 50 ° C. than the melting temperature of silicate is more preferable. As such an inorganic foaming agent, silicon carbide, silicon nitride, aluminum nitride, or a mixture thereof is preferable in that the pore diameter to be generated is small and stable sound absorbing performance is obtained. The amount of inorganic foaming agent added varies depending on the specific gravity, pore diameter and water permeability, firing conditions, and type of foaming agent of the target porous ceramic sound-absorbing material. From the viewpoint of enhancing the performance, the inorganic foaming agent is added to the ceramic raw material in an amount of 0.02% by mass or more, and preferably 0.05% by mass or more. On the other hand, in order to maintain the mechanical strength of the sound absorbing material, the inorganic foaming agent is added to the ceramic raw material at a ratio of 1.0% by mass or less, and more preferably 0.5% by mass or less.
セラミックス原料には、透水性を高める点で、軽量骨材を添加するのが好ましい。軽量骨材としては、フライアッシュバルーン、パーライト、シラスバルーンもしくはガラスバルーンなどの球状体または珪藻土などが好ましい。軽量骨材の添加量は、気孔径を均一化し、透水性を高める点で、４０質量％以下が好ましく、３５質量％以下がより好ましい。一方、高い透水性を得る点で、１質量％以上が好ましく、５質量％以上がより好ましい。また、無機系発泡剤のほか、タルク、カオリンもしくはバーミキュライトまたはそれらの混合物などからなる粘土質原料および金属酸化物などを好ましく配合することができ、これらを原料中に１質量％〜４０質量％配合するのが好ましい。 It is preferable to add a lightweight aggregate to the ceramic raw material in terms of increasing water permeability. As the lightweight aggregate, a spherical body such as fly ash balloon, perlite, shirasu balloon or glass balloon, or diatomaceous earth is preferable. The addition amount of the lightweight aggregate is preferably 40% by mass or less, and more preferably 35% by mass or less from the viewpoint of uniformizing the pore diameter and increasing water permeability. On the other hand, in terms of obtaining high water permeability, 1% by mass or more is preferable, and 5% by mass or more is more preferable. In addition to inorganic foaming agents, clay raw materials and metal oxides composed of talc, kaolin, vermiculite, or a mixture thereof can be preferably blended, and these are blended in the raw materials in an amount of 1% to 40% by weight. It is preferable to do this.
調製後のセラミックス原料は、ボールミルまたはアトマイザーなどの粉砕機により、乾式または湿式で粉砕して微粉末の原料混合物とする。より均一で微細な粉粒体に粉砕する点から、湿式粉砕が好ましい。粉砕は、平均粒径が、好ましくは５μｍ〜１００μｍ、より好ましくは５μｍ〜２０μｍになるまで続ける。粉砕後、原料混合物は、発泡体内のガス溜りを減少させるために、焼成前に、平均粒径０．１ｍｍ〜１ｍｍ程度の大きさに造粒するのが好ましい。造粒は、窯業において採用されている種々の方法で行うことができ、たとえば、湿式粉砕して得られた泥將をスプレードライ法により顆粒状に造粒することができる。 The prepared ceramic raw material is pulverized dry or wet with a pulverizer such as a ball mill or an atomizer to obtain a fine powder raw material mixture. Wet pulverization is preferable from the viewpoint of pulverizing into a more uniform and fine powder. The pulverization is continued until the average particle diameter is preferably 5 μm to 100 μm, more preferably 5 μm to 20 μm. After pulverization, the raw material mixture is preferably granulated to an average particle size of about 0.1 mm to 1 mm before firing in order to reduce gas accumulation in the foam. Granulation can be performed by various methods employed in the ceramic industry. For example, mud obtained by wet pulverization can be granulated into particles by a spray drying method.
つぎに、原料の粉粒体を型枠内に敷き詰め、原料粉粒体の溶融温度以上に加熱し、無機系発泡剤から発生する気体により、多孔質セラミックス吸音材を製造する。具体的には、たとえば、コージェライトとムライトの混合物などの耐熱材料で形成された枡型の成形型枠の底部に、セラミックス原料粉粒体を敷き詰め、原料粉粒体の軟化溶融点より１０℃〜３００℃高い１１００℃〜１３００℃の温度で、０．４時間〜１２時間加熱する。また、好ましくは、１１５０℃〜１２５０℃の温度で、０．５時間〜３時間加熱し、溶融発泡後、徐冷して脱型する。 Next, the raw material granular material is spread in a mold, heated to a temperature equal to or higher than the melting temperature of the raw material granular material, and a porous ceramic sound-absorbing material is produced by a gas generated from the inorganic foaming agent. Specifically, for example, ceramic raw material powder particles are spread on the bottom of a saddle-shaped mold frame formed of a heat-resistant material such as a mixture of cordierite and mullite, and 10 ° C. from the softening and melting point of the raw material powder particles. Heat at a temperature of 1100 ° C. to 1300 ° C., which is higher by −300 ° C., for 0.4 to 12 hours. Further, preferably, heating is performed at a temperature of 1150 ° C. to 1250 ° C. for 0.5 hours to 3 hours, and after melt foaming, the mold is gradually cooled and demolded.
加熱工程では、型枠に蓋を載せて発泡させると、発泡の高さを制御し、発泡倍率を調整することができる。また、型枠の底面および側面には、離型を容易にし、歩留まりを高くするために、離型剤層を形成するのが望ましい。離型剤としては、焼成時に不融なアルミナなどを分散させた液状物を底面および側面に塗布してもよいが、アルミナなどの耐火材料からなるセラミックスペーパーを利用すると離型性が特に良好である。型枠成型を行なう場合などでは、焼成後、得られたセラミックス成形体には、型枠との接触面に、気孔断面が露出していない層、いわゆる、スキン層が生じる場合がある。このような場合は、気孔断面を露出させるため、スキン層を切削、切断または研磨するなどの加工を施す。 In the heating process, when the lid is placed on the mold and foamed, the height of foaming can be controlled and the foaming ratio can be adjusted. Further, it is desirable to form a release agent layer on the bottom and side surfaces of the mold in order to facilitate mold release and increase the yield. As the mold release agent, a liquid material in which infusible alumina or the like is dispersed may be applied to the bottom and side surfaces at the time of firing. However, when a ceramic paper made of a refractory material such as alumina is used, the mold release property is particularly good. is there. In the case of performing mold forming or the like, a layer in which the pore cross section is not exposed, that is, a so-called skin layer may be formed on the contact surface with the mold after the firing. In such a case, processing such as cutting, cutting or polishing the skin layer is performed in order to expose the pore cross section.
得られるセラミックスは、多孔質吸音材であり、ＪＩＳ−Ａ１４０５による周波数１０００Ｈｚにおける垂直入射吸音率が２０％以上であり、好ましくは３０％以上であり、より好ましくは４０％以上である。また、垂直入射吸音率が、周波数１０００±１００Ｈｚの帯域に極大ピークを有する多孔質セラミックス体を製造することができる。したがって、特に、車両用の吸音材として有用である。このセラミックス吸音材の比重は、機械的強度を維持する観点から、アルキメデス法による比重で、０．４以上が好ましく、０．５以上がより好ましい。一方、セラミックス吸音材の比重は、空隙率を高めて優れた吸音性能を発揮する観点から、１．０以下が好ましく、０．８以下がより好ましい。本明細書において、吸音率は、ＪＩＳ−Ａ１４０５による垂直入射吸音率で表示する。また、比重はいずれもアルキメデス法により表す。 The obtained ceramic is a porous sound-absorbing material, and the normal incident sound absorption coefficient at a frequency of 1000 Hz according to JIS-A1405 is 20% or more, preferably 30% or more, more preferably 40% or more. In addition, a porous ceramic body having a maximum incident peak in a band of a frequency of 1000 ± 100 Hz can be produced. Therefore, it is particularly useful as a sound absorbing material for vehicles. The specific gravity of the ceramic sound-absorbing material is preferably 0.4 or more, more preferably 0.5 or more, as determined by Archimedes method from the viewpoint of maintaining mechanical strength. On the other hand, the specific gravity of the ceramic sound-absorbing material is preferably 1.0 or less, more preferably 0.8 or less, from the viewpoint of increasing the porosity and exhibiting excellent sound-absorbing performance. In this specification, the sound absorption coefficient is expressed as a normal incident sound absorption coefficient according to JIS-A1405. The specific gravity is expressed by the Archimedes method.
吸音材の気孔径は、周波数１０００Ｈｚにおける吸音率を高め、好ましくは１０００±１００Ｈｚにおいて吸音率が極大ピークを呈するようにする観点から、算術平均値で０．５ｍｍ〜１．３ｍｍが好ましく、０．６ｍｍ〜１．２ｍｍがより好ましい。本明細書において、気孔径は、光学顕微鏡により試験体の表面を写真撮影し、３０個の気孔をランダムにピックアップし、気孔径を算術平均する方法により評価する。 The pore diameter of the sound absorbing material is preferably 0.5 mm to 1.3 mm in terms of arithmetic average value from the viewpoint of increasing the sound absorption rate at a frequency of 1000 Hz, and preferably exhibiting a maximum peak at 1000 ± 100 Hz. 6 mm to 1.2 mm is more preferable. In the present specification, the pore diameter is evaluated by a method in which the surface of the test specimen is photographed with an optical microscope, 30 pores are randomly picked up, and the pore diameter is arithmetically averaged.
無機系発泡剤により形成される気孔は、各気孔が独立したものではなく、複数の気孔間で相互に連通し、立体網状構造体を形成しているものと推認され、製造される吸音材は、他の特性が同じであれば、連通性の大きい吸音材ほど吸音率が大きくなる傾向がある。本明細書において、吸音材の連通性は、透水性により評価することとし、透水性は、つぎに示す方法により試験する。この試験方法は、林誠、他２名による論文「多孔質セラミックスの製造技術に関する研究」（平成元年度茨城県工業技術センター研究報告第１７号ｐｐ７７〜７８）における透水性試験方法に基くものである。まず、外径９２ｍｍ、厚さ１５ｍｍの円柱状の試験体を調製し、水中に浸漬して飽和状態とする。つぎに、内径３０ｍｍのビニール管の端部に試験体を固定し、水が漏れないようにビニール管の周囲を粘土でシールする。ビニール管の他端から２００ｃｍ3の水を注ぎ入れ、試験体の下に用意したビーカーに透水した水を受ける。全量の水が試験体を透水した時間を測定し、単位面積および単位時間当たりの透水量を算定し、その数値をもって、試験体の透水性を評価する。本発明の吸音材は、吸音率が高い点で、透水性が３．５ｇ／ｈ・ｃｍ2以上のものが好ましく、１０ｇ／ｈ・ｃｍ2以上のものがより好ましい。 The pores formed by the inorganic foaming agent are not independent of each pore, but are inferred to form a three-dimensional network structure by communicating with each other between a plurality of pores. If the other characteristics are the same, the sound absorption rate tends to increase as the sound absorption material has higher communication characteristics. In this specification, the connectivity of the sound absorbing material is evaluated by water permeability, and the water permeability is tested by the following method. This test method is based on the water permeability test method in the paper “Studies on the manufacturing technology of porous ceramics” by Makoto Hayashi and two others (1989, Ibaraki Prefectural Industrial Technology Center Research Report No. 17 pp 77-78). is there. First, a cylindrical specimen having an outer diameter of 92 mm and a thickness of 15 mm is prepared and immersed in water to obtain a saturated state. Next, the specimen is fixed to the end of a 30 mm inner diameter vinyl tube, and the periphery of the vinyl tube is sealed with clay so that water does not leak. 200 cm 3 of water is poured from the other end of the vinyl tube, and water is passed through a beaker prepared under the specimen. Measure the time that the entire amount of water permeated the specimen, calculate the amount of water per unit area and unit time, and evaluate the permeability of the specimen using the values. The sound-absorbing material of the present invention preferably has a water permeability of 3.5 g / h · cm 2 or more, more preferably 10 g / h · cm 2 or more, in terms of high sound absorption.
実施例１
珪酸塩含有物として流紋岩（珪酸塩含有率９７質量％以上）（軟化溶融点１１５０℃）８１部と、カオリン９部と、軽量骨材（フライアッシュバルーン）１０部と、無機系発泡剤として炭化珪素０．１部とを配合した後、ボールミルにより湿式粉砕し、平均粒径を１０μｍに調製した。つぎに、セラミックス吸音材におけるガス溜りを減少するために、スプレードライ法により平均粒径０．８ｍｍ程度の顆粒状の原料粉粒体とした。原料粉粒体の組成を表１に示す。
Example 1
Rhyolite (silicate content 97 mass% or more) (softening melting point 1150 ° C.) 81 parts, kaolin 9 parts, lightweight aggregate (fly ash balloon) 10 parts, inorganic foaming agent Then, 0.1 parts of silicon carbide was blended and wet pulverized with a ball mill to prepare an average particle size of 10 μm. Next, in order to reduce gas accumulation in the ceramic sound-absorbing material, a granular raw material granular material having an average particle diameter of about 0.8 mm was obtained by a spray drying method. Table 1 shows the composition of the raw material granules.
つぎに、コージェライトとムライトの混合物からなり、内寸が縦３５０ｍｍ×横３５０ｍｍ×深さ１００ｍｍの枡型状の耐熱性型枠の底面と側面に、セラミックスシートを敷設した。つづいて、上述の原料粉粒体３ｋｇを、型枠内に入れ、均一に敷き詰めた後、型枠を電気炉に入れ、３時間かけて１２００℃まで昇温し、１２００℃で４０分間保持した。その後、自然徐冷および冷風徐冷し、５時間後に型枠から脱離した。つづいて、サンプルからスキン層を切削し、厚さ１５ｍｍの板状体とし、旋盤にて外径４０ｍｍ（高周波用）および外径９２ｍｍ（低周波用）の試験体を形成した。その後、垂直入射吸音率、比重、気孔径および透水性を評価した。その結果を表１に示す。また、吸音率を図１に示す。表１および図１から明らかなとおり、得られた多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける垂直入射吸音率が４３．２％であり、１０００Ｈｚにおいて吸音率が極大ピークを有していた。なお、８００℃以上でも吸音率の低下がなく、高い耐熱性が認められた。 Next, a ceramic sheet was laid on the bottom and side surfaces of a saddle-shaped heat-resistant mold made of a mixture of cordierite and mullite and having an internal dimension of 350 mm long × 350 mm wide × 100 mm deep. Subsequently, 3 kg of the above-mentioned raw material granular material was put in a mold and spread uniformly, then the mold was put in an electric furnace, heated to 1200 ° C. over 3 hours, and held at 1200 ° C. for 40 minutes. . Thereafter, natural slow cooling and cold air slow cooling were performed, and after 5 hours, the mold was detached. Subsequently, the skin layer was cut from the sample to obtain a plate-like body having a thickness of 15 mm, and a test body having an outer diameter of 40 mm (for high frequency) and an outer diameter of 92 mm (for low frequency) was formed using a lathe. Thereafter, normal incident sound absorption coefficient, specific gravity, pore diameter and water permeability were evaluated. The results are shown in Table 1. The sound absorption rate is shown in FIG. As apparent from Table 1 and FIG. 1, the obtained porous ceramic sound-absorbing material had a normal incidence sound absorption coefficient of 43.2% at a frequency of 1000 Hz, and had a maximum peak at 1000 Hz. In addition, even if it was 800 degreeC or more, there was no fall of a sound absorption factor and high heat resistance was recognized.
実施例２
配合成分を、表１に示すように、珪酸塩含有物（流紋岩）６３質量％、無機系発泡剤（炭化珪素）０．０７質量％、カオリン７質量％、軽量骨材（フライアッシュバルーン）３０質量％とした以外は実施例１と同様にして多孔質セラミックス製吸音材を製造した。製造した吸音材の吸音率を図１に示す。また、各種特性値を表１に示す。これらの結果から明らかなとおり、得られた多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける垂直入射吸音率が２５．２％であり、１０００Ｈｚにおいて吸音率が極大ピークを有していた。
Example 2
As shown in Table 1, the compounding ingredients are 63% by mass of a silicate-containing material (rhyolite), 0.07% by mass of an inorganic foaming agent (silicon carbide), 7% by mass of kaolin, lightweight aggregate (fly ash balloon ) A porous ceramic sound-absorbing material was produced in the same manner as in Example 1 except that the content was 30% by mass. The sound absorption rate of the manufactured sound absorbing material is shown in FIG. Various characteristic values are shown in Table 1. As is clear from these results, the obtained porous ceramic sound-absorbing material had a normal incidence sound absorption coefficient of 25.2% at a frequency of 1000 Hz, and had a maximum peak at 1000 Hz.
比較例１
配合成分を、表１に示すように、珪酸塩含有物（流紋岩）４５質量％、無機系発泡剤（炭化珪素）０．０７質量％、カオリン５質量％、軽量骨材（フライアッシュバルーン）５０質量％とした以外は実施例１と同様にして多孔質セラミックス製吸音材を製造した。製造した吸音材の吸音率を図２に示す。また、各種特性値を表１に示す。これらの結果から明らかなとおり、得られた多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける垂直入射吸音率が１２．２％であり、１０００±１００Ｈｚには吸音率の極大ピークがなかった。
Comparative Example 1
As shown in Table 1, the compounding components are 45% by mass of silicate-containing material (rhyolite), 0.07% by mass of inorganic foaming agent (silicon carbide), 5% by mass of kaolin, lightweight aggregate (fly ash balloon ) A porous ceramic sound-absorbing material was produced in the same manner as in Example 1 except that the amount was 50% by mass. The sound absorption rate of the manufactured sound absorbing material is shown in FIG. Various characteristic values are shown in Table 1. As is apparent from these results, the obtained porous ceramic sound-absorbing material had a normal incident sound absorption coefficient at a frequency of 1000 Hz of 12.2%, and there was no maximum sound absorption coefficient peak at 1000 ± 100 Hz.
比較例２
配合成分を、表１に示すように、珪酸塩含有物（流紋岩）７２質量％、無機系発泡剤（炭化珪素）０．１８質量％、カオリン８質量％、軽量骨材としてフライアッシュバルーンの代わりに珪藻土を２０質量％とし、１２００℃での焼成時間を１２０分間とした以外は実施例１と同様にして多孔質セラミックス製吸音材を製造した。製造した吸音材の吸音率を図２に示す。また、各種特性値を表１に示す。これらの結果から明らかなとおり、得られた多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける垂直入射吸音率が１２．２％であり、１０００±１００Ｈｚには吸音率の極大ピークがなかった。
Comparative Example 2
As shown in Table 1, the blending components are as follows: silicate-containing material (rhyolite) 72% by mass, inorganic foaming agent (silicon carbide) 0.18% by mass, kaolin 8% by mass, fly ash balloon as a lightweight aggregate A porous ceramic sound-absorbing material was produced in the same manner as in Example 1 except that 20% by mass of diatomaceous earth was used instead of and the firing time at 1200 ° C. was 120 minutes. The sound absorption rate of the manufactured sound absorbing material is shown in FIG. Various characteristic values are shown in Table 1. As is apparent from these results, the obtained porous ceramic sound-absorbing material had a normal incident sound absorption coefficient at a frequency of 1000 Hz of 12.2%, and there was no maximum sound absorption coefficient peak at 1000 ± 100 Hz.
比較例３
配合成分を、表１に示すように、珪酸塩含有物（流紋岩）８１質量％、無機系発泡剤（炭化珪素）０．１質量％、カオリン９質量％、軽量骨材（フライアッシュバルーン）１０質量％とし、１２００℃での焼成時間を１２０分間とした以外は実施例１と同様にして多孔質セラミックス製吸音材を製造した。製造した吸音材の吸音率を図２に示す。また、各種特性値を表１に示す。これらの結果から明らかなとおり、得られた多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける垂直入射吸音率が１０．４％であり、１０００±１００Ｈｚには吸音率の極大ピークがなかった。
Comparative Example 3
As shown in Table 1, the compounding ingredients are 81% by mass of silicate-containing material (rhyolite), 0.1% by mass of inorganic foaming agent (silicon carbide), 9% by mass of kaolin, lightweight aggregate (fly ash balloon ) A porous ceramic sound-absorbing material was produced in the same manner as in Example 1 except that the content was 10% by mass and the firing time at 1200 ° C. was 120 minutes. The sound absorption rate of the manufactured sound absorbing material is shown in FIG. Various characteristic values are shown in Table 1. As is clear from these results, the obtained porous ceramic sound-absorbing material had a normal incident sound absorption coefficient at a frequency of 1000 Hz of 10.4%, and there was no maximum sound absorption coefficient peak at 1000 ± 100 Hz.
なお、有機系吸音材として、ポリエーテル系半硬質ポリウレタンフォーム（気孔径０．２ｍｍ、密度５０ｋｇ／ｍ3、厚さ１０ｍｍ）について、同様に、吸音率を測定したところ、周波数１０００Ｈｚでの吸音率は２６．０％であったが、９０℃以上では吸音性が低下し、使用が困難であり、耐熱性が認められなかった。
In addition, when the sound absorption coefficient was similarly measured for a polyether semi-rigid polyurethane foam (pore diameter 0.2 mm,
今回開示された実施の形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
本発明の多孔質セラミックス製吸音材は、周波数１０００Ｈｚにおける吸音特性が優れるため、特に、高温で使用される車両用の吸音材として有用である。さらに、高周波域での吸音性に優れる部材との複合材とすれば、広域な周波数において優れた吸音性を確保することができる。 Since the sound absorbing material made of porous ceramics of the present invention has excellent sound absorbing characteristics at a frequency of 1000 Hz, it is particularly useful as a sound absorbing material for vehicles used at high temperatures. Furthermore, if it is a composite material with a member excellent in sound absorption in a high frequency region, excellent sound absorption in a wide frequency range can be ensured.
Claims (8)
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103539482A (en) * | 2013-11-07 | 2014-01-29 | 陈松 | Ultra-microporous ceramic sound-absorbing material and preparation method thereof |
| CN106747604A (en) * | 2016-12-23 | 2017-05-31 | 林圣灼 | A kind of heat-insulating and sound-absorbing light material and preparation method thereof |
| CN112645692A (en) * | 2020-12-28 | 2021-04-13 | 信阳师范学院 | Perforated sound-absorbing ceramic prepared by taking low-grade nonmetallic associated ore as main raw material and preparation method thereof |
| CN114591099A (en) * | 2022-03-23 | 2022-06-07 | 中国地质大学（北京） | Porous material based on blast furnace ash as foaming agent and preparation method thereof |
| CN116283221A (en) * | 2023-03-01 | 2023-06-23 | 南京声远声学科技有限公司 | Micro-perforated sound-absorbing ceramic material based on Taihu sediment and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5864291A (en) * | 1981-10-13 | 1983-04-16 | 旭硝子株式会社 | Sound absorbing material |
| JPS62207781A (en) * | 1986-03-07 | 1987-09-12 | 日本碍子株式会社 | Inorganic sound absorber |
| JPH05221743A (en) * | 1992-02-04 | 1993-08-31 | Riken Corp | Porous ceramic acoustic material |
| JPH08217523A (en) * | 1995-02-17 | 1996-08-27 | Sekisui Chem Co Ltd | Inorganic sound absorbing board |
| JP2003181300A (en) * | 2001-12-18 | 2003-07-02 | Toyota Motor Corp | Inorganic fiber comprising noble metal-containing compound oxide and catalytic structural body |
| JP2004244270A (en) * | 2003-02-14 | 2004-09-02 | Inoac Corp | Silica porous body and method of manufacturing the same |
-
2005
- 2005-09-30 JP JP2005288301A patent/JP2007099533A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5864291A (en) * | 1981-10-13 | 1983-04-16 | 旭硝子株式会社 | Sound absorbing material |
| JPS62207781A (en) * | 1986-03-07 | 1987-09-12 | 日本碍子株式会社 | Inorganic sound absorber |
| JPH05221743A (en) * | 1992-02-04 | 1993-08-31 | Riken Corp | Porous ceramic acoustic material |
| JPH08217523A (en) * | 1995-02-17 | 1996-08-27 | Sekisui Chem Co Ltd | Inorganic sound absorbing board |
| JP2003181300A (en) * | 2001-12-18 | 2003-07-02 | Toyota Motor Corp | Inorganic fiber comprising noble metal-containing compound oxide and catalytic structural body |
| JP2004244270A (en) * | 2003-02-14 | 2004-09-02 | Inoac Corp | Silica porous body and method of manufacturing the same |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103539482A (en) * | 2013-11-07 | 2014-01-29 | 陈松 | Ultra-microporous ceramic sound-absorbing material and preparation method thereof |
| CN106747604A (en) * | 2016-12-23 | 2017-05-31 | 林圣灼 | A kind of heat-insulating and sound-absorbing light material and preparation method thereof |
| CN112645692A (en) * | 2020-12-28 | 2021-04-13 | 信阳师范学院 | Perforated sound-absorbing ceramic prepared by taking low-grade nonmetallic associated ore as main raw material and preparation method thereof |
| CN114591099A (en) * | 2022-03-23 | 2022-06-07 | 中国地质大学（北京） | Porous material based on blast furnace ash as foaming agent and preparation method thereof |
| CN116283221A (en) * | 2023-03-01 | 2023-06-23 | 南京声远声学科技有限公司 | Micro-perforated sound-absorbing ceramic material based on Taihu sediment and preparation method thereof |
| CN116283221B (en) * | 2023-03-01 | 2023-11-14 | 南京声远声学科技有限公司 | Micro-perforated sound-absorbing ceramic material based on Taihu sediment and preparation method thereof |
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