JPH0354176A - Production of cellular ceramics - Google Patents
Production of cellular ceramicsInfo
- Publication number
- JPH0354176A JPH0354176A JP18739189A JP18739189A JPH0354176A JP H0354176 A JPH0354176 A JP H0354176A JP 18739189 A JP18739189 A JP 18739189A JP 18739189 A JP18739189 A JP 18739189A JP H0354176 A JPH0354176 A JP H0354176A
- Authority
- JP
- Japan
- Prior art keywords
- ceramic
- particles
- ceramic particles
- ceramics
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 108
- 230000001413 cellular effect Effects 0.000 title claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000002245 particle Substances 0.000 claims abstract description 39
- 239000011362 coarse particle Substances 0.000 claims abstract description 11
- 239000002994 raw material Substances 0.000 claims abstract description 7
- 238000005187 foaming Methods 0.000 claims abstract description 4
- 239000000203 mixture Substances 0.000 claims abstract description 3
- 239000010419 fine particle Substances 0.000 claims description 14
- 238000010304 firing Methods 0.000 claims description 8
- 238000009413 insulation Methods 0.000 abstract description 7
- 238000001354 calcination Methods 0.000 abstract description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 18
- 239000011230 binding agent Substances 0.000 description 13
- 239000006260 foam Substances 0.000 description 13
- 238000000034 method Methods 0.000 description 12
- 239000012528 membrane Substances 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 239000000835 fiber Substances 0.000 description 8
- 238000005192 partition Methods 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 4
- 239000002270 dispersing agent Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229940088990 ammonium stearate Drugs 0.000 description 2
- JPNZKPRONVOMLL-UHFFFAOYSA-N azane;octadecanoic acid Chemical compound [NH4+].CCCCCCCCCCCCCCCCCC([O-])=O JPNZKPRONVOMLL-UHFFFAOYSA-N 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000004088 foaming agent Substances 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 239000012774 insulation material Substances 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000007569 slipcasting Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- UOYIYWCAYFTQLH-UHFFFAOYSA-N 3,7-dinitro-1,3,5,7-tetrazabicyclo[3.3.1]nonane Chemical compound C1N2CN([N+](=O)[O-])CN1CN([N+]([O-])=O)C2 UOYIYWCAYFTQLH-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 241000219112 Cucumis Species 0.000 description 1
- 235000015510 Cucumis melo subsp melo Nutrition 0.000 description 1
- 241000861914 Plecoglossus altivelis Species 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 229920005822 acrylic binder Polymers 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000004872 foam stabilizing agent Substances 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- -1 maggotium Chemical compound 0.000 description 1
- 238000004421 molding of ceramic Methods 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052575 non-oxide ceramic Inorganic materials 0.000 description 1
- 239000011225 non-oxide ceramic Substances 0.000 description 1
- 235000012149 noodles Nutrition 0.000 description 1
- 229910052574 oxide ceramic Inorganic materials 0.000 description 1
- 239000011224 oxide ceramic Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は泡状の外観を有するセラミックスを製造する方
法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing ceramics with a foam-like appearance.
従来、高温で使用される断鮎材としては、セラミックス
質のファイバーが主として用いられてきた。その理由は
セラミックファイハーは工業的に大瓜に製造するのに適
しているためである。すなわち、セラミックファイバー
は、溶融しているセラミックスを滴下させ、これに水蒸
気などの高速気流を吹きつけて、融液を糸状にする方法
により製造されており、極めて生産性かよい。Conventionally, ceramic fibers have been mainly used as sweetfish material used at high temperatures. The reason is that ceramic fifers are suitable for industrial production into melons. That is, ceramic fibers are manufactured by a method in which molten ceramics are dropped and a high-speed air stream such as water vapor is blown thereto to form the molten liquid into threads, which is extremely productive.
しかしながら、セラミックファイバーは、断ｊＪｌｌ材
としては多くの問題を有している。However, ceramic fibers have many problems as cutting materials.
このうち最も大きな問題は、セラミソクファイバーが高
温使用時に収縮することである。この収縮により断熱層
に亀裂が入り、断島効果が著しく低下する。これは、フ
ァイバーどうしか固着していないことと、ファイバーか
ガラス質でありこれが桔晶化する時に物質移動か起きる
ことか原因となっている。The biggest problem among these is that ceramic fibers shrink when used at high temperatures. This shrinkage causes cracks in the insulation layer, significantly reducing the island-breaking effect. This is because the fibers are the only ones that stick together, and the fibers are glassy, which may cause mass transfer when crystallizing.
また、セラミックファイバー断貼材では、ファイバ一間
の空間は連続しており、気体分子は自由に運動できるが
、ただ大きな対流を起こさせないことにより断熱効果を
維持している。しかし、熱伝導の理論から考えても、気
体分子が自由に運動できるということは断熱材としては
根本的に問題である。In addition, in ceramic fiber insulation materials, the space between the fibers is continuous and gas molecules can move freely, but the insulation effect is maintained by not allowing large convection to occur. However, even when considered from the theory of heat conduction, the fact that gas molecules can move freely is a fundamental problem for insulation materials.
そこで、本発明者らは、特願昭６３−１０９２１号にお
いて、球面状をなす緻密質多結晶セラミックス膜が隔離
された多数個のセル状の空間を囲み、このセラミックス
膜が連続した構造を有する泡状セラミノクスを堤案じた
。このような泡状セラミノクスは、例えば以下のような
方〆去で製遺される。すなわち、セラミックス粒子、及
びバインダーなどの各抄有機成分を溶媒中で混合し、撹
拌機で泡立て、泡が安定した状態で乾燥して泡状をなす
或形体を得た後、仮焼し、更に焼成することにより泡状
セラミックスを製造することができる。この泡状セラミ
ックスでは、セル状の空間か材料内部で隔離されて独立
状態となっており、気体分子は１つのセル内という限定
された範囲内で移動するたけであるので、優れた断八効
果を得ることかできる。Therefore, the present inventors proposed in Japanese Patent Application No. 63-10921 that a spherical dense polycrystalline ceramic film surrounds a large number of isolated cellular spaces, and that the ceramic film has a continuous structure. I thought about foamy ceraminox. Such foamed ceraminox is produced, for example, by the following method. That is, each organic component of the paper, such as ceramic particles and a binder, is mixed in a solvent, foamed with a stirrer, and dried while the foam is stable to obtain a foam-like shape, which is then calcined and further Foamed ceramics can be produced by firing. In this foam ceramic, it is isolated in the cell-shaped space or inside the material and becomes an independent state, and the gas molecules only move within the limited range of one cell, so it has an excellent cutting effect. Can you get it?
たたし、このような泡状セラミックスを実際に製遣する
場合、微細構造の制御が困難であることが判明した。す
なわち、セラミックス粒子及び有機成分を含む原料を発
泡させると、膜形成物質はその表面張力により球形にな
ろうとする。こうして形成される膜は隣接するセル状空
間どうしの隔壁中央部で膜厚が薄くなる。そして、場合
によっては、隔壁中央部に穴があいて隣接するセル状空
間かつながってしまい、その結果前述した断熱効果が得
られなくなる。また、セル状空間の大きさ及びセラミッ
クス膜の膜厚がともに制御された泡状セラミックスを製
造できる条件を設定することも困難であった。特に、セ
ラミックス膜の膜厚は、泡状セラミックスの熱伝導率な
どの特性、及び機峨的強度を左右する要因寸あるため、
これを制御することは極めて重要となる。However, it has been found that it is difficult to control the fine structure when actually producing such foamed ceramics. That is, when a raw material containing ceramic particles and an organic component is foamed, the film-forming material tends to take on a spherical shape due to its surface tension. The film thus formed becomes thinner at the center of the partition walls between adjacent cellular spaces. In some cases, a hole is formed in the center of the partition wall and adjacent cellular spaces are connected, and as a result, the above-mentioned heat insulation effect cannot be obtained. Furthermore, it was also difficult to set conditions that would allow production of foam-like ceramics in which both the size of the cellular spaces and the thickness of the ceramic film were controlled. In particular, the thickness of the ceramic film is a factor that affects the properties such as thermal conductivity and mechanical strength of foamed ceramics.
Controlling this is extremely important.
本発明は前記問題点を解決するためになされたものであ
り、耐熱断熱材として高い性能を−ａする泡状セラミッ
クスを工業的に安定して製造できる方ｔ去を提１共する
ことを目的とする。The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for industrially and stably producing foamed ceramics that exhibit high performance as a heat-resistant heat insulating material. shall be.
本発明の泡状セラミックスの製造方広は、セラミックス
粒子及び有機戊分を含有する原料を発泡させた後、焼成
することにより、緻密質多桔晶セラミックス膜が隔離さ
れた多数個のセル状の空間を囲み、該セラミックス膜が
連続した構造を有する泡状セラミックスを製造するにあ
たり、前記セラミックス粒子として、セル状の空間を隔
離する緻密質多結晶セラミンクス膜の所望の膜厚と同程
度の粒径をＧする、セラミックス微粒子を凝集させたセ
ラミックス粗粒子と、セラミックス微粒子との混合物を
用いたことを特徴とするものである。The method for producing foamed ceramics of the present invention is to foam a raw material containing ceramic particles and an organic fraction, and then sinter it to form a large number of cells in which dense polycrystalline ceramic films are isolated. In producing a foamed ceramic that surrounds a space and has a continuous ceramic film structure, the ceramic particles have a particle size comparable to the desired film thickness of the dense polycrystalline ceramic film that isolates the cellular space. The present invention is characterized in that it uses a mixture of coarse ceramic particles obtained by agglomerating ceramic fine particles and fine ceramic particles.
本発明は以下のような知見に基づいてなされたものであ
る。すなわち、セル状の空間を隔てるセラミックス膜が
形或される途中においては、隔壁中央部の膜厚が薄くな
る方向に膜形成物質が移動して膜の３重点の肉厚が大き
くなり、しだいに移動度が少なくなってある時点で膜形
成物質の移動か停Ｉヒする。この場合、膜形成物質の移
動度が充分高いと、最も薄くなる部分の膜厚は、膜形或
物質中に分散されているセラミックス粒子の拉径とほほ
同程度になることか判明した。したかって、セラミック
ス原料として、目標とする所望の膜厚と同程度の粒径を
有する、セラミックス微粒子を凝集させたセラミックス
粗粒子を用いれば、セル状の空間の隔壁となるセラミッ
クス膜の膜厚を制御することができる。ただし、セラミ
ックス粗拉子のみを用いると、粒子間隙が大きくなるた
め、セラミックス粗粒子間の粒子間隙を埋めるためにセ
ラミック微粒子を添加する。なお、セラミックス膜を均
質化するためには、セラミックス粗拉子の密度と、セラ
ミックス粗粒子間の粒子間隙に充填された状態のセラミ
ックス微粒子の密度とが同等となるようにすることが望
ましい。The present invention was made based on the following findings. In other words, during the formation of a ceramic membrane that separates cellular spaces, the membrane-forming substance moves in the direction where the thickness of the membrane at the center of the partition wall becomes thinner, and the thickness of the triple point of the membrane increases, gradually increasing the thickness of the membrane. The mobility of the film-forming substance decreases and at a certain point the movement of the film-forming substance stops. In this case, it has been found that if the mobility of the film-forming substance is sufficiently high, the film thickness at the thinnest part will be approximately the same as the diameter of the ceramic particles dispersed in the film shape or substance. Therefore, if ceramic coarse particles made by agglomerating ceramic fine particles and having a particle size similar to the target desired film thickness are used as the ceramic raw material, the thickness of the ceramic film that becomes the partition wall of the cell-shaped space can be reduced. can be controlled. However, if only the ceramic coarse particles are used, the gaps between the particles become large, so fine ceramic particles are added to fill the gaps between the coarse ceramic particles. In order to homogenize the ceramic film, it is desirable that the density of the ceramic coarser particles be equal to the density of the ceramic fine particles filled in the gaps between the ceramic coarse particles.
本発明の泡状セラミックスを製造する具体的な方注とし
ては、以下のような方広を採用てきる。As a specific method for manufacturing the foamed ceramics of the present invention, the following methods can be adopted.
一般的な方法としては、セラミックスｍ位子、セラミッ
クス微粒子、分散剤、バインダー、整泡剤を溶媒中でよ
く混合してスリップを調製し、撹件機で泡立て、泡が安
定した状態で乾燥して泡状をなす成形体を得た後、仮焼
してバインダーなどの有機成分を焼散させ、更に高温（
泡状セラミックスの使用温度よりも高温）で焼或する方
法か挙げられる。The general method is to prepare a slip by thoroughly mixing ceramic particles, ceramic fine particles, a dispersant, a binder, and a foam stabilizer in a solvent, foaming with an agitator, and drying the foam in a stable state. After obtaining a foam-like molded product, it is calcined to burn off organic components such as binders, and then heated to a higher temperature (
One example is a method of firing at a temperature higher than the temperature at which foamed ceramics are used.
本発明において、セラミックス膜を構或する材質は、各
セルの独立性を維持し、しかも材料としての強度を維持
するために、緻密かつ高強度で、断熱性の高いものであ
ることが要求される。このような材質としては、アルミ
ナ、ジルコニア、マグ不シア、ムライト、スピネルなど
の酸化物系セラミックスや、窒化ケイ素、炭化ケイ素な
どの非酸化物系セラミックスが挙げられる。これらのセ
ラミックスのうちでは、特にアルミナ系セラミックスか
望ましい。アルミナ系セラミックスは、最も一般的に用
いられているセラミックスであり、強度及び耐熱性に優
れている。なお、アルミナはシリカなどに比べて熱伝導
率が高いが、セラミックス膜の断面積は空間部の断面積
に比べて少ないので、膜部分を伝わる熱量は少なく、断
熱効果は満たされる。なお、アルミナ系セラミックスを
高い温度で使用していると、結晶粒子か成長し、磯城的
強度が低下するおそれかある。これを防止するためには
、アルミナに１００ｐｐｍから０．２ ｗｔ％の少量の
マグネシアを含有させることか有効である。In the present invention, the material constituting the ceramic membrane is required to be dense, high strength, and highly insulating in order to maintain the independence of each cell and maintain the strength of the material. Ru. Examples of such materials include oxide ceramics such as alumina, zirconia, maggotium, mullite, and spinel, and non-oxide ceramics such as silicon nitride and silicon carbide. Among these ceramics, alumina ceramics are particularly desirable. Alumina ceramics are the most commonly used ceramics and have excellent strength and heat resistance. Note that alumina has higher thermal conductivity than silica, etc., but since the cross-sectional area of the ceramic membrane is smaller than the cross-sectional area of the space, the amount of heat transmitted through the membrane is small, and the insulation effect is satisfied. Note that if alumina ceramics are used at high temperatures, crystal grains may grow and the Isoshiro strength may decrease. In order to prevent this, it is effective to incorporate a small amount of magnesia from 100 ppm to 0.2 wt% into alumina.
また、アルミナに少量のマグネシアを含有させると、本
発明の泡状セラミックスを製造する際の焼成時に異常粒
子戊長を抑制するのにも有効である。Further, when alumina contains a small amount of magnesia, it is effective to suppress abnormal particle elongation during firing when producing the foamed ceramic of the present invention.
本発明において、セラミックス微粒子を凝集させた粗粒
子を調製する方法としては、各種の方法を採用できる。In the present invention, various methods can be employed to prepare coarse particles obtained by agglomerating ceramic fine particles.
一般的には、セラミックス微粒子及ヒバインダーをスプ
レードライヤーなどの造粒機で粗拉子にし、これを仮焼
するだけでもよい。In general, fine ceramic particles and a binder may be coarsely pulverized using a granulator such as a spray dryer, and then calcined.
また、前記のように造粒によって得られた粗粒子を加圧
した後、粗粉砕して篩て整拉してもよい。Alternatively, after pressurizing the coarse particles obtained by granulation as described above, the particles may be coarsely pulverized, sieved, and sieved.
また、セラミックス微粒子及びバインダーをスリップキ
ャスト法で固め、これを粗粉砕して篩で整拉し、仮焼し
て粗粒子を調製することも可能である。セラミックス粗
拉子は溶媒中で凝集がほぐれないことが必要であり、そ
のために前述したように仮焼が有効であるが、微粒子を
凝集させるときに使用した結合剤が溶媒に冶解しなけれ
ば、仮焼は不必要である。また、仮焼する場合の温度条
件は、粗粒子の密度が微粒子による充填密度と同等とな
りやすいように、焼成収縮が生じない温度範囲であるこ
とが望ましい。It is also possible to prepare coarse particles by hardening ceramic fine particles and a binder by slip casting, coarsely pulverizing the solid, sieving, and calcining. It is necessary that the ceramic particles do not disintegrate in the solvent, and for this purpose, calcining is effective as mentioned above, but if the binder used to aggregate the fine particles does not dissolve in the solvent. , calcination is unnecessary. Further, the temperature conditions for calcination are preferably within a temperature range in which no firing shrinkage occurs so that the density of coarse particles tends to be equal to the packing density of fine particles.
原料を混合してスリップを調製する際、少ない溶媒量で
粘度の低いスリップを調製することか望ましい。この場
合、セラミック微粒子に関しては、その一次粒子まで充
分にほぐれていることが望ましい。When preparing a slip by mixing raw materials, it is desirable to prepare a slip with a low viscosity using a small amount of solvent. In this case, it is desirable that the ceramic fine particles are sufficiently loosened down to their primary particles.
バインダーは泡状の戊形体に強度を付与するために添ｂ
ＩＩされる。すなわち、泡状の成形体には乾燥収縮峙に
クラックが入りやすいが、バインダーによってクラック
発生を防止できる。バインダーとしては一般的にセラミ
ックスのプレス成形なとこ用いられる有機バインダーで
も差し支えないが、スリップの粘度を極端に上昇させる
ことのないスリップキャスティング用バインダーが望ま
しい。A binder is added to give strength to the foam-shaped body.
II will be done. That is, although foam-like molded products are prone to cracking during drying and shrinkage, cracks can be prevented by the binder. The binder may be an organic binder that is generally used in press molding of ceramics, but a binder for slip casting that does not excessively increase the viscosity of the slip is desirable.
分散剤としては、ポリアクリル酸塩、ポリ塩ｆヒアルミ
ニウムなどが有効である。たたし、分散剤として一般に
使用されているナトリウム塩はセラミックス中に叉種の
金属イオンを持ち込むため不都合であり、５℃種の金属
イオンを持ち込むことのないアンモニウム塩が望ましい
。As the dispersant, polyacrylate, polysalt hyaluminum, etc. are effective. However, sodium salts, which are generally used as dispersants, are inconvenient because they introduce different types of metal ions into ceramics, and ammonium salts that do not introduce 5°C types of metal ions are desirable.
整泡剤は泡が消失しないように安定させるために用いら
れる。整泡剤はいわゆるセッケンでもよいが、金属イオ
ンを含まないものが望まし＜、的えばステアリン酸アン
モニウムなどが適当てある。Foam stabilizers are used to stabilize foam so that it does not disappear. The foam stabilizer may be a so-called soap, but it is preferable to use one that does not contain metal ions; for example, ammonium stearate is suitable.
本発明の泡状セラミックスを製遣する方法は、前述した
スリップを泡立てる方広のみに限定されるものではなく
、通常の発泡材料の製造方法と同様な方法も採用できる
。この場合、セラミックスｔＩＩ粒子、セラミックス微
粒子、発泡剤をポリウレタンやポリスチレンなどのプラ
スチック又はゴムに混合した混練物を調製し、これを発
泡させ、固化した後、焼成する。The method for manufacturing the foamed ceramics of the present invention is not limited to the above-described foaming process of slip, but may also be the same as the method for producing ordinary foamed materials. In this case, a kneaded product is prepared by mixing ceramic tII particles, ceramic fine particles, and a foaming agent with plastic or rubber such as polyurethane or polystyrene, which is foamed, solidified, and then fired.
本発明方法を用いれば、セラミックス膜の膜厚を制御す
ることができ、膜厚の充分厚いセラミソクス膜でセル状
の空間を隔離することができる。By using the method of the present invention, the thickness of the ceramic film can be controlled, and cellular spaces can be isolated with a sufficiently thick ceramic film.
このため、隔壁中央部に穴があいて隣接するセル状空間
がつながることはなく、セル状の空間が材料内部で確実
に隔離されて独立状態となっており、気体分子の移動が
１つのセル内に眼定されるので、優れた断熱効果を得る
ことができる。しかも、セラミックス膜の膜厚が制御さ
れているので、泡状セラミックスの熱伝導率などの特性
もある程度制御することかできる。For this reason, there is no hole in the center of the partition wall that connects adjacent cellular spaces, and the cellular spaces are reliably isolated and independent within the material, allowing gas molecules to move only through one cell. Since it is determined within Moreover, since the thickness of the ceramic film is controlled, the properties of the foamed ceramic, such as its thermal conductivity, can also be controlled to a certain extent.
また、高温で焼結されたセラミックス中に１４１じ込め
られた空間は、その温度において雰囲気と同し気圧であ
るため、常Ｒまで冷却されると減圧状態となる。したが
って、泡状セラミックスか使用される温度より高い温度
で焼成すれば、使用温度ではセル内は減圧状態であり、
セル内の気体の衝突回数か減少し、断熱効果か向上する
。Furthermore, since the space 141 enclosed in the ceramic sintered at a high temperature has the same atmospheric pressure as the atmosphere at that temperature, it becomes a reduced pressure state when cooled to normal R. Therefore, if the ceramic foam is fired at a temperature higher than the temperature at which it is used, the inside of the cell will be under reduced pressure at the temperature at which it will be used.
The number of gas collisions within the cell is reduced and the insulation effect is improved.
更に、焼成時の雰囲気を真空にすれば、泡状セラミック
スのセル状の空間内を真空にすることかできる。以下、
この方法について説明する。すなわち、泡状の成形体の
段階で膜部分のセラミックス粒子の充填密度は、理論密
度の３５〜６０％程度であり、成形体は通気性を有する
。そして、この成形体では膜の一部にバインダー、分散
剤、整泡剤などの有機戊分が充填されている。これを空
気中で仮焼すると、有機成分は焼散してなくなるが、セ
ラミックス粒子の充埴密度は前記のように３５〜６０％
程度のまま変化がない。これを真空炉に入れ、仮焼体の
周囲のガスを排気することにより、泡内に閉じ込められ
た気体分子は膜を構成するセラミソクス粒子の間隙を通
過して徐々に（Ｆｉ．焼体から抜ナていき、最終的には
真空となる。この状態で史にＷ ｉＦｊｒし、例えばア
ルミナ系セラミックスでは１４００℃程度になると、通
気性がなくなりセル状の空間は閉空間となる。その後、
更に高い温度、例えば１８００℃で焼或して室温まで冷
却する。このようにして製造されたセル状の空間か真空
になっている泡状セラミックスでは、断熱効果をより一
肋向上することができる。Furthermore, by making the atmosphere during firing a vacuum, it is possible to make the inside of the cellular space of the foam ceramic a vacuum. below,
This method will be explained. That is, the packing density of the ceramic particles in the membrane portion at the stage of the foam-like molded product is about 35 to 60% of the theoretical density, and the molded product has air permeability. In this molded body, a part of the membrane is filled with organic components such as a binder, a dispersant, and a foam stabilizer. When this is calcined in the air, the organic components are burnt out and disappear, but the filling density of the ceramic particles is 35 to 60% as mentioned above.
There is no change in the degree. By placing this in a vacuum furnace and exhausting the gas around the calcined body, the gas molecules trapped in the bubbles gradually pass through the gaps between the ceramic particles that make up the membrane (Fi. Extracted from the calcined body). In this state, for example, in alumina ceramics, when the temperature reaches about 1400°C, the air permeability disappears and the cellular space becomes a closed space.After that,
It is then calcined at a higher temperature, for example 1800°C, and cooled to room temperature. In the foamed ceramics manufactured in this way, in which the cellular spaces are in a vacuum, the heat insulation effect can be further improved.
以下、本発明の実施例を説明する。 Examples of the present invention will be described below.
実施例１
拉径０，２μ頂で９９．９％のアルミナ粉１００部、ス
トイキオメトリックスビネル０５部、イオン交換水１．
Ｏ Ｏ部、ＰＶＡ２部をボールミルにて１昼夜混合し
た。これをスプレードライヤーで造拉した。この逍粒粉
を１トン／ｃｍ２の圧力で加圧して圧粉体とし、乳鉢で
粗粉砕した後、粒径１ｏ〜２０μｍのものと拉径５〜１
０即のものとを分級した。これらをそれそれ空気中、ｇ
ｏｏ’ｃで２時間仮焼して粗拉子を調製した。Example 1 100 parts of 99.9% alumina powder with a diameter of 0.2μ, 05 parts of stoichiometric vinyl, 1.0 parts of ion-exchanged water.
Parts of OO and 2 parts of PVA were mixed in a ball mill for one day and night. This was made using a spray dryer. This green powder is pressurized at a pressure of 1 ton/cm2 to form a compact, and after coarsely pulverizing it in a mortar, it is divided into powders with a particle diameter of 10 to 20 μm and a powder with a diameter of 5 to 1 μm.
It was classified into 0 items and 0 items. Each of these in the air, g
Crude noodles were prepared by calcining for 2 hours at oo'c.
前記のようにして得られたアルミナ粗粒子（粒径ｌＯ〜
２０坤又は５〜１０４）７Ｄ部、アルミナ微粒子３０部
、ステアリン酸アンモニウム１部、ポリアク１ル酸アン
モニウム１部、アクリル系バインダー１０部、イオン交
換水２０部を混合しながら撹拌機で泡立てた。泡が安定
した後、乾燥機で乾燥して、２種類の戊形体（それそれ
使用したアルミナ粗拉子が異なる）を得た。Coarse alumina particles obtained as described above (particle size lO~
20 parts or 5 to 104) 7D parts, 30 parts of alumina fine particles, 1 part of ammonium stearate, 1 part of ammonium polyacrylic acid, 10 parts of acrylic binder, and 20 parts of ion-exchanged water were mixed and foamed with a stirrer. After the foam became stable, it was dried in a dryer to obtain two types of rod-shaped bodies (each using a different alumina sieve).
これらの戊形体を空気中、８００’Ｃで２時間焼或し、
バインダーなどの有賎物を焼散させた。更に、真空中、
１６５０℃で２時間焼成して２種の泡状アルミナセラミ
ックスを得た。These hollow bodies were fired in air at 800'C for 2 hours,
Binders and other solid materials were burned. Furthermore, in vacuum,
Two types of foamed alumina ceramics were obtained by firing at 1650°C for 2 hours.
これらの泡状セラミックスに関しては、セラミックス膜
の膜厚は一方か１５ｎ１他方か７μｍであり、セル状空
間の平均径は両者とも５０μロであった。また、セラミ
ックス膜の膜厚は、分級されたアルミナ粗粒子のうち最
大径のものが焼成収縮した大きさとほぼ等しいものであ
った。また、セラミックス膜は膜厚のばらつきが少ない
ものであった。Regarding these foamed ceramics, the thickness of the ceramic film was 15μm on one side and 7μm on the other, and the average diameter of the cellular spaces was 50μm in both cases. Further, the thickness of the ceramic film was approximately equal to the size of the largest diameter of the classified alumina coarse particles that shrunk during firing. Furthermore, the ceramic film had little variation in film thickness.
実施例２
実施例１と同様にして、最大径２０μｍ及び１０μｍ（
拉径１０〜２〇一及び５〜ｌＯμ）のアルミナ粗拉子を
得た。Example 2 In the same manner as in Example 1, maximum diameters of 20 μm and 10 μm (
Alumina coarse alumina with a diameter of 10 to 201 μm and a diameter of 5 to 10 μm were obtained.
アルミナ粗拉子（粒径ｌＯ〜２０４又は５〜１０μ）７
０部、アルミナ微粒子３０部、未加硫ゴム２０部、発泡
剤としてジニトロペンタメチレンテトラミン１部を混合
した。これらを１４０℃に加熱して允泡させた。これら
の発泡体を空気中で２時間焼成して２種の泡状セラミッ
クスを得た。Alumina coarse particle size (particle size lO~204 or 5~10μ) 7
0 parts, 30 parts of alumina fine particles, 20 parts of unvulcanized rubber, and 1 part of dinitropentamethylenetetramine as a foaming agent were mixed. These were heated to 140°C to foam. These foams were fired in air for 2 hours to obtain two types of foamed ceramics.
これらの泡状セラミックスに関しては、セラミックス膜
の膜厚は一方か１５μ、他方が７μｍであり、セル状空
間の平均径は両者とも１００−であった。Regarding these foamed ceramics, the thickness of the ceramic film was 15 μm on one side and 7 μm on the other side, and the average diameter of the cellular spaces was 100 − in both cases.
以上詳述したように本発明方法を用いれば、膜厚の制御
された泡状セラミソクスを安定して製遣することができ
、優れた特性を有する断熱材などの工業的供給が可能と
なる。As detailed above, by using the method of the present invention, it is possible to stably produce foamed ceramic socks with a controlled film thickness, and it becomes possible to industrially supply heat insulating materials with excellent properties.
Claims (1)
せた後、焼成することにより、緻密質多結晶セラミック
ス膜が隔離された多数個のセル状の空間を囲み、該セラ
ミックス膜が連続した構造を有する泡状セラミックスを
製造するにあたり、前記セラミックス粒子として、セル
状の空間を隔離する緻密質多結晶セラミックス膜の所望
の膜厚と同程度の粒径を有する、セラミックス微粒子を
凝集させたセラミックス粗粒子と、セラミックス微粒子
との混合物を用いたことを特徴とする泡状セラミックス
の製造方法。By foaming a raw material containing ceramic particles and an organic component and then firing it, a dense polycrystalline ceramic film surrounds a large number of isolated cell-shaped spaces, and the ceramic film forms a continuous structure. In producing a shaped ceramic, the ceramic particles are ceramic coarse particles made by agglomerating ceramic fine particles and having a particle size comparable to the desired film thickness of a dense polycrystalline ceramic film that isolates cellular spaces; A method for producing foam-like ceramics characterized by using a mixture with ceramic fine particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1187391A JPH0829995B2 (en) | 1989-07-21 | 1989-07-21 | Method for manufacturing foam ceramics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1187391A JPH0829995B2 (en) | 1989-07-21 | 1989-07-21 | Method for manufacturing foam ceramics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0354176A true JPH0354176A (en) | 1991-03-08 |
| JPH0829995B2 JPH0829995B2 (en) | 1996-03-27 |
Family
ID=16205206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1187391A Expired - Fee Related JPH0829995B2 (en) | 1989-07-21 | 1989-07-21 | Method for manufacturing foam ceramics |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0829995B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62197367A (en) * | 1986-02-22 | 1987-09-01 | 黒崎窯業株式会社 | Ceramic sintered body with high aperture rate and manufacture |
-
1989
- 1989-07-21 JP JP1187391A patent/JPH0829995B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62197367A (en) * | 1986-02-22 | 1987-09-01 | 黒崎窯業株式会社 | Ceramic sintered body with high aperture rate and manufacture |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0829995B2 (en) | 1996-03-27 |
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