JPS60224814A - Inorganic fiber - Google Patents

Abstract

PURPOSE:Inorganic fibers that contains, as major components, alumina and silica, further a specific amount of nickel oxide, thus showing improved strength and heat resistance so that no deterioration in physical properties takes place even in continuous use under high-temperature environments. CONSTITUTION:For example, a spinning dope containing an aluminum compound such as basic aluminum chloride, a silicon compound such as silica sol and a nickel compound such as nickel chloride in a dispersion form is extruded into fibers and the resultant fiber precursors are roasted to give the objective fibers which consist of 65-90wt% alumina, 8-33% silica and 0.2-7% nickel oxide where the total of the 3 components accounts for more than 98wt%. Further, a small amount of a water-soluble organic polymer such as PVA is preferably added to the dope in order to improve fiber-forming properties of the dope.

Description

【発明の詳細な説明】 本発明は、高強度を有する耐熱性無機質繊維に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-resistant inorganic fiber having high strength.

約８００℃以上の高温雰囲気で連続使用可能な耐熱性繊
維としてはセラミック繊維が代表的なものであり、近年
はそのすぐれた耐熱性、耐熱衝撃性、軽量性、電気絶縁
性、化学的安定性、吸音性などを生かして、製鉄その他
各種の金属工業、化学工業、機械工業等において断熱材
、高温シール材、補強材、バッキング、消音材、濾材な
どに広く利用されるようになった。しかしながら、最も
代表的なセラミック繊維であるアルミノシリケート質セ
ラミック繊維の場合、その耐熱限界温度は約１５００℃
とされているが、実際にはそれよりもがなり低い温度に
おいても劣化を起こす、すなわち、この繊維は約９８０
　’Ｃ以上に加熱されるとムライト結晶（３Ａ１□０゜
・２ＳｉＯ２）の生成により体積収縮を起こし、もろく
なってしまう。また最大１００〜２００ｍｍ程度の短繊
維しか得られず、粒状物の含有量が多いという欠点もあ
る。また、アルミニウム化合物を主成分とする粘稠な溶
液から前駆体繊維を成形し、これを焼成することにより
製造される多結晶質アルミナ繊維は、融点２０５０℃の
アルミナを主成分とし、本質的には高耐熱性であるが、
約１２００℃以上でコランダム（α−Ａ　Ｉ　ａ　Ｏ３
）への転移を生じ、強度が低下するとともにもろくなる
傾向があるから、この繊維も、実用上の耐熱限界はそれ
ほど高くない。Ceramic fibers are typical heat-resistant fibers that can be used continuously in high-temperature environments of approximately 800°C or higher, and in recent years, their excellent heat resistance, thermal shock resistance, light weight, electrical insulation, and chemical stability have been recognized. Due to its sound-absorbing properties, it has come to be widely used as insulation materials, high-temperature sealing materials, reinforcing materials, backings, sound deadening materials, filter materials, etc. in steel manufacturing and other metal industries, chemical industries, machinery industries, etc. However, in the case of aluminosilicate ceramic fiber, which is the most typical ceramic fiber, its heat resistance limit temperature is approximately 1500°C.
However, in reality, the fiber deteriorates even at lower temperatures, i.e., this fiber has a
When heated above 'C, volumetric shrinkage occurs due to the formation of mullite crystals (3A1□0°・2SiO2) and the material becomes brittle. Another disadvantage is that only short fibers with a maximum length of about 100 to 200 mm can be obtained, and the content of granules is large. In addition, polycrystalline alumina fiber, which is produced by molding a precursor fiber from a viscous solution containing an aluminum compound as its main component and firing it, is composed mainly of alumina with a melting point of 2050°C and essentially consists of has high heat resistance, but
Corundum (α-A I a O3
), which tends to reduce strength and become brittle, so the practical heat resistance limit of this fiber is also not very high.

一方、これらの耐熱性繊維の用途分野における各種設備
は近年ますます高性能化する傾向にあり、それにともな
い、そこで使われる耐熱性繊維材料についても−そう強
度や耐熱性のすぐれたものが要望されるようになった。On the other hand, in recent years, the various types of equipment in which these heat-resistant fibers are used have tended to become more and more sophisticated, and as a result, the heat-resistant fiber materials used there are also required to have excellent strength and heat resistance. It became so.

本発明者らは、上述のような現状を背景に、より高度の
強度および耐熱性を有するセラミック繊維をめて鋭意研
究を重ねた結果、９８重量％以上がＡｌ２Ｏ，、Ｓｉｏ
、およびＮｉＯからなり、Ａｈａ、が６５ないし９０重
量％、Ｓｉｏ、が８ないし３３重量％、ＮｉＯが０．２
〜７重量％である、高性能蕉磯質繊維の発明を完成する
に至った。Against the background of the above-mentioned current situation, the present inventors have conducted extensive research into ceramic fibers with higher strength and heat resistance, and have found that 98% by weight or more of
, and NiO, Aha is 65 to 90% by weight, Sio is 8 to 33% by weight, and NiO is 0.2%.
We have completed the invention of a high-performance bamboo fiber with a content of ~7% by weight.

ＡＬＯ３およびＳ　ｉ　Ｏｚを主成分とし、更に上記特
定の比率でＮｉＯを含有する本発明の繊維は、細く且つ
しなやかで、しかも強度の大きい長繊維状のものとして
容易に製造することができるだけでなく、強度および耐
熱性がすぐれており、１０００℃以上の高温で長時間使
用しても、従来のものよりも物性の低下が少ない。この
ような特長が特に顕著に発現する点で好ましい組成は、
Ａｌ２Ｏ，６８〜８５重量％、Ｓ　１ｏ２１２〜３０重
量％、Ｎ；ｏ　Ｏ，５〜５重量％のものである。The fiber of the present invention, which contains ALO3 and SiOz as main components and further contains NiO in the above-mentioned specific ratio, can not only be easily manufactured as a long fiber that is thin and flexible, but also has high strength. It has excellent strength and heat resistance, and even when used for a long time at high temperatures of 1000°C or higher, its physical properties deteriorate less than conventional products. Preferred compositions in which these features are particularly prominent are:
Al2O, 68-85% by weight, S1o212-30% by weight, N;oO, 5-5% by weight.

本発明の耐熱性繊維を製造するには、多結晶質アルミナ
繊維の製造法に準じて、原料化合物を溶解または懸濁さ
せた紡糸液から前駆体繊維を製造し、これを焼成すれば
よい。適当な原料化合物としては次のようなものがある
。In order to produce the heat-resistant fiber of the present invention, precursor fibers may be produced from a spinning solution in which raw material compounds are dissolved or suspended, and then fired, in accordance with the method for producing polycrystalline alumina fibers. Suitable raw material compounds include the following.

アルミニウム化合物：塩基性塩化アルミニウム、塩基性
硝酸アルミニウム等の無機酸塩；酢酸アルミニウム、ギ
酸アルミニウム、ギ酸酢酸アルミニウム、乳酸アルミニ
ウム等の有機酸塩等、Ａｌ２Ｏ，に換算して好ましくは
１０重量％以上の濃度まで水に可溶のもの。Aluminum compound: Inorganic acid salts such as basic aluminum chloride and basic aluminum nitrate; Organic acid salts such as aluminum acetate, aluminum formate, aluminum acetate formate, aluminum lactate, etc., preferably 10% by weight or more in terms of Al2O. soluble in water up to a concentration.

ケイ素化合物：エチルシリケート、メチルシリケート等
のアルコキサイドを加水分解して水溶性ないし水分敵性
コロイドとしたもの、およびシリカゾル等。Silicon compounds: Water-soluble or water-friendly colloids obtained by hydrolyzing alkoxides such as ethyl silicate and methyl silicate, and silica sol.

ニッケル化合物；塩化ニッケル、硝酸ニッケル、シュウ
酸ニッケル、硫酸ニッケル、酢酸ニッケル等。Nickel compounds; nickel chloride, nickel nitrate, nickel oxalate, nickel sulfate, nickel acetate, etc.

上記原料化合物を水に溶解し、Ａｌ２Ｏ，とじて６５〜
９０重量％、５ｉｎ２として８〜３３重量％、ＮｉＯと
して０．２〜６重量％の比率の混合溶液を調製する。そ
の際、溶解を速やかにし、また完全にするために、エチ
ルアルコール、メチルアルコール、ジメチルホルムアミ
ド、ジメチルアセトアミド、ジメチルスルホキサイド、
アセトン等の、水溶性有機溶媒を添加してもよい。その
後、ろ過により不溶解物その他の固形物を除いたのち、
粘度が１０〜１０００ポアズになるまで濃縮して紡糸液
とする。紡糸液には、紡糸する際の曳糸性を向上させる
ため、ポリエチレンオキサイド、ポリビニルアルコール
、ポリアクリル酸エステル、ポリメタクリル酸エステル
、カルボキシメチルセルロース、メチルセルロース等の
水溶性有機重合体を少量添加することが望ましい。The above raw material compound was dissolved in water, Al2O, and 65~
A mixed solution having a ratio of 90% by weight, 8 to 33% by weight as 5in2, and 0.2 to 6% by weight as NiO is prepared. At that time, in order to quickly and completely dissolve, ethyl alcohol, methyl alcohol, dimethylformamide, dimethylacetamide, dimethyl sulfoxide,
A water-soluble organic solvent such as acetone may also be added. Then, after removing insoluble matter and other solids by filtration,
The spinning solution is concentrated until the viscosity becomes 10 to 1000 poise. A small amount of water-soluble organic polymers such as polyethylene oxide, polyvinyl alcohol, polyacrylic ester, polymethacrylic ester, carboxymethyl cellulose, methyl cellulose, etc. may be added to the spinning solution in order to improve stringability during spinning. desirable.

紡糸液を繊維化するには、例えば直径０．０５〜５ＩＩ
Ｉ１１１程度のノズルから調湿された空気中に押出す方
法、高圧気体で吹き飛ばすカー、回転体の遠心力を利用
する方法など、この種の繊維製造に使用される製法のい
ずれによってもよいが、長繊維を必要とする場合は、押
出成形法が適当である。形成された繊維は直ちに熱風で
乾燥する。In order to make the spinning solution into fibers, for example, the diameter is 0.05 to 5 II.
Any manufacturing method used for this type of fiber manufacturing may be used, such as extruding it into humidity-controlled air through a nozzle of about I111, blowing it off with high-pressure gas, or using the centrifugal force of a rotating body. If long fibers are required, extrusion molding is suitable. The formed fibers are immediately dried with hot air.

得られた前駆体繊維を、約１０００〜１５００°Ｃ１好
ましくは１ｏｏｏ〜１２００℃の酸化性雰囲気で焼成す
ると、本発明の繊維が得られる。The fiber of the present invention is obtained by firing the obtained precursor fiber in an oxidizing atmosphere at about 1000-1500° C., preferably 100-1200° C.

以下、実施例および比較例を示して本発明を説明する。The present invention will be described below with reference to Examples and Comparative Examples.

実施例　１ ギ酸アルミニウム（ＡＩ（ＯＨ）（ＨＣＯＯｈｌの水溶
液（濃度はＡ１□Ｏ１として１０重量％）、シリカゾル
（５ｉ０２濃度２０重量％の分散液）および酢酸ニッケ
ルＩ　Ｎ　！　（ＣＨ３Ｃ００）２・４Ｈ２０］　を、
ＡｌｚＯ＊　：　Ｓ；０２　：　Ｎｉ０＝７０．５　：
２７．５　：　２　（重量比）になるように混合し、こ
れにポリアクリル酸エステルを３重量％加えて混合した
後、ろ過した。Example 1 Aluminum formate (AI(OH) (HCOOhl aqueous solution (concentration 10% by weight as A1□O1), silica sol (5i02 concentration 20% by weight dispersion) and nickel acetate I N! (CH3C00)2.4H20] of,
AlzO*: S;02: Ni0=70.5:
The mixture was mixed so that the ratio was 27.5:2 (weight ratio), and 3% by weight of polyacrylic ester was added thereto and mixed, followed by filtration.

ろ液を減圧濃縮し、得られた紡糸液（粘度２３０ポアズ
）を、直径０．２５ｍ鰺のノズル３６個を有する紡糸口
金から押出し、次いで、形成された前駆体繊維を１００
０℃の空気中で１時間焼成し、酸化物繊維とした。The filtrate was concentrated under reduced pressure, the resulting spinning solution (viscosity 230 poise) was extruded through a spinneret with 36 nozzles of 0.25 m diameter, and then the precursor fibers formed were
It was fired in air at 0° C. for 1 hour to obtain oxide fibers.

得られた繊維は、平均直径が８．３ｕｍ、引張り強度が
２５０Ｋ［１／１１１１１”の高強度のものであり、し
かも、１２００℃で３時間加熱した後も２２３にｇ）Ｉ
ＩＩ１１２の引張強度を示す耐熱性のすぐれたものであ
った。The obtained fibers have a high strength with an average diameter of 8.3 um and a tensile strength of 250K [1/11111'', and even after heating at 1200°C for 3 hours, the fibers have a high tensile strength of 223g)I.
It had excellent heat resistance showing a tensile strength of II112.

実施例　２ ギ酸酢酸アルミニウム［ＡＩ（ＯＨ）（１−１ｃＯＯ）
（ＣＨ，Ｃ００）］の水溶液（濃度はＡ１□０．として
１２重量％）、シリカゾル（Ｓ　ｉ　０２濃度２０重量
％の分散液）および酢酸ニッケル［Ｎ１（ＣＨ＝ＣＯＯ
）２・４Ｈ２０］　を、Ａｌ２Ｏ，：　５ｉｆｔ　：Ｎ
ｉ０＝８１　：　１５　：　４　（重量比）になるよう
に混合し、以下、実施例１と同様にして、酸化物繊維を
製造した。Example 2 Aluminum formate acetate [AI(OH) (1-1 cOO)
(CH,C00)] (concentration: 12% by weight as A1
)2・4H20], Al2O,: 5ift :N
They were mixed so that i0=81:15:4 (weight ratio), and the same procedure as in Example 1 was carried out to produce oxide fibers.

得られた繊維の平均直径は９．６側、引張り強度は１８
３ＫＩｉ／ｗ２であった。この繊維は、１２００’Ｃで
３時間加熱した後も、１５９／ｌｌｌｌ１１２の引張強
度を示した。The average diameter of the obtained fibers was 9.6, and the tensile strength was 18.
It was 3KIi/w2. The fiber exhibited a tensile strength of 159/llll12 even after heating at 1200'C for 3 hours.

比較例 酢酸ニッケルを添加せず、組成をＡ１□Ｏ＝　：　Ｓ；
０２＝７２：２８　に変更したほかは実施例１と同様に
して、酸化物繊維を製造した。Comparative Example: No nickel acetate was added, and the composition was A1□O=:S;
Oxide fibers were produced in the same manner as in Example 1 except that the ratio was changed to 02=72:28.

得られた繊維は、平均直径が８．７測、引張強度が１５
９Ｋｇ／醜輸２．１２００℃で３時間加熱後の引張強度
が６１に８／Ｉ＋ｌ１１２のものであった。The resulting fibers had an average diameter of 8.7 mm and a tensile strength of 15 mm.
The tensile strength after heating at 9Kg/2.1200°C for 3 hours was 61 to 8/I+112.

代理人　弁理士　板井−鵬Agent Patent Attorney Itai-Peng

Claims (1)

【特許請求の範囲】[Claims] ９８重量％以上がＡＬＯ，、Ｓｉｎ、およびＮｉＯから
なり、ＡＩ、０３が６５ないし９０重量％、ＳｉＯ２が
８ないし３３重量％、ＮｉＯが０．２〜７重量％である
無機質繊維。An inorganic fiber comprising 98% by weight or more of ALO, Sin, and NiO, 65 to 90% by weight of AI, 03, 8 to 33% by weight of SiO2, and 0.2 to 7% by weight of NiO.