JPH0365574A - Production of porous material comprising carbon and silicon carbide - Google Patents
Production of porous material comprising carbon and silicon carbideInfo
- Publication number
- JPH0365574A JPH0365574A JP19793589A JP19793589A JPH0365574A JP H0365574 A JPH0365574 A JP H0365574A JP 19793589 A JP19793589 A JP 19793589A JP 19793589 A JP19793589 A JP 19793589A JP H0365574 A JPH0365574 A JP H0365574A
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- silicon carbide
- inorganic polysilazane
- silicon
- carbon fiber
- 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.)
- Pending
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 27
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000011148 porous material Substances 0.000 title description 5
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 25
- 239000004917 carbon fiber Substances 0.000 claims abstract description 25
- 229920001709 polysilazane Polymers 0.000 claims abstract description 18
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 17
- 238000010438 heat treatment Methods 0.000 claims abstract description 16
- 239000012298 atmosphere Substances 0.000 claims abstract description 13
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 7
- 239000010703 silicon Substances 0.000 claims abstract description 7
- 230000001590 oxidative effect Effects 0.000 claims description 7
- 238000005121 nitriding Methods 0.000 claims description 6
- 239000000835 fiber Substances 0.000 abstract description 22
- 230000014759 maintenance of location Effects 0.000 abstract description 3
- 239000011230 binding agent Substances 0.000 abstract description 2
- 239000002759 woven fabric Substances 0.000 abstract description 2
- 239000004744 fabric Substances 0.000 abstract 1
- 239000004745 nonwoven fabric Substances 0.000 abstract 1
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 21
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 11
- 239000007788 liquid Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 229920001971 elastomer Polymers 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 4
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 4
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 4
- 229920002379 silicone rubber Polymers 0.000 description 4
- 239000004945 silicone rubber Substances 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 150000002431 hydrogen Chemical class 0.000 description 3
- 239000005046 Chlorosilane Substances 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 229910021417 amorphous silicon Inorganic materials 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- KOPOQZFJUQMUML-UHFFFAOYSA-N chlorosilane Chemical group Cl[SiH3] KOPOQZFJUQMUML-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005470 impregnation Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 150000003961 organosilicon compounds Chemical class 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 2
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910004205 SiNX Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000005055 methyl trichlorosilane Substances 0.000 description 1
- JLUFWMXJHAVVNN-UHFFFAOYSA-N methyltrichlorosilane Chemical compound C[Si](Cl)(Cl)Cl JLUFWMXJHAVVNN-UHFFFAOYSA-N 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920003203 poly(dimethylsilylene-co-phenylmethyl- silylene) polymer Polymers 0.000 description 1
- 229920003257 polycarbosilane Polymers 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000005049 silicon tetrachloride Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
Landscapes
- Porous Artificial Stone Or Porous Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は平面燃焼用多孔板、対流を放射に変える伝熱
変換素子、高温除塵フィルター等高温での使用に耐える
多孔体の製造法に関するものである。[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for manufacturing porous bodies that can withstand use at high temperatures, such as porous plates for flat combustion, heat transfer conversion elements that convert convection into radiation, and high-temperature dust removal filters. It is.
炭素材料は１０００°Ｃ以上の高温においても強度低下
がなくまた高い熱伝導性を持つところから高温材料とし
て期待されている。炭素の多孔体は平面燃焼用多孔板、
対流伝熱で得た熱を放射伝熱で逃がす伝熱変換素子、高
温の含塵ガスの除塵フィルター等として期待されている
。この目的には４０から８０容積％の高い気孔率が要求
され、この要求に適した炭素の多孔体の素材としては炭
素繊維がある。これは直径３〜２０ｎの長繊維もしくは
長さと直径の比が３〜５０になるように切断した短繊維
の形態で通常利用される。長繊維の場合、２次元または
３次元に織ったプリフォームを作製している。Carbon materials are expected to be used as high-temperature materials because they do not decrease in strength even at high temperatures of 1000° C. or higher and have high thermal conductivity. The carbon porous body is a perforated plate for flat combustion,
It is expected to be used as a heat transfer conversion element that releases heat obtained through convection heat transfer through radiation heat transfer, and as a dust removal filter for high-temperature dust-containing gas. For this purpose, a high porosity of 40 to 80% by volume is required, and carbon fiber is a material for the carbon porous body that is suitable for this requirement. It is usually used in the form of long fibers with a diameter of 3 to 20 nm or short fibers cut to have a length-to-diameter ratio of 3 to 50. In the case of long fibers, a two-dimensional or three-dimensional woven preform is produced.
短繊維の場合、短繊維同志のからみあいによる保形性を
利用して底形しプリフォームを作製している。In the case of short fibers, a preform is produced by taking advantage of the shape-retaining properties of the short fibers due to their intertwining.
このようなプリフォームは強度が弱く、また、空気中で
５００°Ｃを越えると酸化し、使用に耐えられなくなる
。そこで、繊維同志の接合と耐酸化性の付与を目的とし
て炭化ケイ素を繊維表面に被覆することが知られている
。例えば特開平１−１６７２９０号公報には、プリフォ
ームに高分子有機ケイ素化合物を含浸させ、熱処理して
これを炭化ケイ素に転化させたのち、さらにその表面に
化学気相蒸着法により炭化ケイ素または窒化ケイ素の皮
膜を形成させる方法が開示されている。第１層の被覆す
る高分子有機ケイ素化合物にはポリカルボシラン、ポリ
シラスチレン等、１０００−１６００’Ｃの加熱処理に
よって炭化ケイ素に転化にするものが使用されている。Such preforms have low strength and oxidize in air at temperatures exceeding 500°C, making them unusable. Therefore, it is known to coat the fiber surface with silicon carbide for the purpose of bonding the fibers together and imparting oxidation resistance. For example, in JP-A-1-167290, a preform is impregnated with a polymer organosilicon compound, heat treated to convert it into silicon carbide, and then silicon carbide or nitride is added to the surface by chemical vapor deposition. A method of forming a silicon film is disclosed. The polymer organosilicon compound covered by the first layer includes polycarbosilane, polysilastyrene, and the like, which can be converted into silicon carbide by heat treatment at 1000-1600'C.
また第２層に被覆する炭化ケイ素の原料としてメチルト
リクロルシラン、水素およびアルゴンの混合気体を使用
し、これらを１ｏｏｏ〜１６５０°Ｃの温度で反応させ
て炭化ケイ素を膜状に析出させている。窒化ケイ素膜の
場合には、四塩化ケイ素、アンモニア水素およびアルゴ
ンの混合気体が使用されている。このようにして耐熱性
のみならず、耐酸化性のすぐれた多孔体を得ている。Furthermore, a mixed gas of methyltrichlorosilane, hydrogen, and argon is used as a raw material for the silicon carbide coated on the second layer, and these are reacted at a temperature of 100 to 1650°C to precipitate silicon carbide in the form of a film. In the case of silicon nitride membranes, a gas mixture of silicon tetrachloride, hydrogen ammonia and argon is used. In this way, a porous body with excellent not only heat resistance but also oxidation resistance is obtained.
前述の方法においては炭化ケイ素は炭素繊維の表面に積
層されるので炭素繊維との密着が不十分であった。また
、炭素繊維より熱膨張率が大きいので、多孔体使用時の
加熱、冷却の繰返しによって被覆層に亀裂が入ったり、
剥離して、基材の炭素繊維の酸化損傷という問題もあっ
た。この発明は上記のような問題点を解決するためにな
されたものであり、密着性のよい炭化ケイ素層を生成す
る方法を提供することを目的とする。In the above-mentioned method, silicon carbide was laminated on the surface of carbon fibers, so that adhesion to the carbon fibers was insufficient. In addition, since the coefficient of thermal expansion is higher than that of carbon fiber, the coating layer may crack due to repeated heating and cooling when using a porous material.
There was also the problem of peeling and oxidation damage to the carbon fiber base material. This invention was made to solve the above-mentioned problems, and an object thereof is to provide a method for producing a silicon carbide layer with good adhesion.
本発明者らは上記目的を遠戚するべく鋭意検討の結果、
炭素繊維プリフォームに無機ポリシラザンを含浸させ、
非窒化性かつ非酸化性雰囲気で加熱して炭素繊維表面の
炭素を無機ポリシラザン中のケイ素と反応させて炭化ケ
イ素に転化することにより炭素繊維との密着性にすぐれ
かつ亀裂、剥離等を生じない被覆層を形成しうることを
見出して本発明を完成するに至った。The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that
Impregnating the carbon fiber preform with inorganic polysilazane,
By heating in a non-nitriding and non-oxidizing atmosphere, the carbon on the surface of the carbon fiber reacts with the silicon in the inorganic polysilazane and is converted into silicon carbide, which provides excellent adhesion to the carbon fiber and does not cause cracks or peeling. The present invention was completed by discovering that a coating layer can be formed.
炭素繊維プリフォームは長繊維の２次元あるいは３次元
の織物であってもよいし短繊維を、短繊維同志のからみ
あいによる保形性を利用して成形したプリフォームであ
ってもよい。十分な保形性が得られない等の場合には有
機あるいは無機のバインダーを成形助剤として添加して
もよい。繊維の直径に特に制約はないが、３−以上２Ｏ
ｎ以下が好ましい。３ｎ以下だと多孔体の比表面積が太
きいので表層の炭化ケイ素の雰囲気ガスとの接触面積が
大きく・この結果使用時に酸化の進行力（早く、生成さ
れる酸化ケイ素が多孔体の強度低下をもたらす。The carbon fiber preform may be a two-dimensional or three-dimensional woven fabric of long fibers, or may be a preform formed by molding short fibers using shape retention due to the intertwining of the short fibers. If sufficient shape retention cannot be obtained, an organic or inorganic binder may be added as a forming aid. There are no particular restrictions on the diameter of the fibers, but 3- or more 2O
It is preferably n or less. If it is less than 3n, the specific surface area of the porous body is large, so the contact area of the silicon carbide on the surface layer with the atmospheric gas is large.As a result, during use, the oxidation progress force (early, the generated silicon oxide reduces the strength of the porous body) bring.
一方、２０−以上だと繊維同志の接触面積が少ないので
、炭化ケイ素を媒介にした接合が不十分となり、強度の
低い、多孔体しか得られない。繊維の充填密度の上昇に
よって強度を向上させることもできるが、その場合気孔
率が低下して多孔体としての機能を損なう。短繊維の場
合、長さと直径の比を好ましくは３以上５０以下とする
。３以下だと低い気孔率しか得られず、一方５０以上だ
と成形以前にからみあって塊になりやすく、気孔径の揃
った多孔体を成形することが困難になる。繊維はＰＡＮ
系であってもピッチ系であってもよい。炭素繊維プリフ
ォームは必要により予めジクロロメタン等の有機溶剤で
洗浄してから無機ポリシラザンを含浸させる。On the other hand, if it is 20 or more, the contact area between the fibers is small, so the bonding through silicon carbide becomes insufficient, and only a porous body with low strength is obtained. Although the strength can be improved by increasing the packing density of the fibers, in this case the porosity decreases and the function as a porous body is impaired. In the case of short fibers, the length to diameter ratio is preferably 3 or more and 50 or less. If it is less than 3, only a low porosity will be obtained, while if it is more than 50, it will tend to become entangled and form lumps before molding, making it difficult to mold a porous body with uniform pore diameters. Fiber is PAN
It may be a system or a pitch system. The carbon fiber preform is washed in advance with an organic solvent such as dichloromethane, if necessary, and then impregnated with the inorganic polysilazane.
無機ポリシラザンはクロロシラン、Ｈ４−ａｓｌｃｌｍ
（ａ＝１．２．３．４）を溶剤に希釈してアンモニアＮ
Ｈ，と反応させることによって得られるエラストマーで
あり、本発明の方法にはＨ，５ｉＣ１，単体もしくは１
２ｓｆｃ１ｇを主体とした異種のクロロシランの混合物
を原料とすることにより得られる常温で液状のものが好
ましい。合成時の溶剤としてはベンゼン、ジエチルエー
テル、ジクロロメタン、テトラヒドロフラン、ピリジン
等が適用できるが、合成される無機ポリシラザンの構造
、組成、分子量は溶剤の種類によって若干異なる。しか
し、いずれも水素、窒素、ケイ素からなり炭素は含まれ
ない。例えば（ＨｚＳｉＮＨ） ｘ、 （ＨｚＳｉＮ
Ｈ） ｘ （（ＨｚＳｉ）＋、ｓＮ） ）’等の構造を
有するものが知られている。Inorganic polysilazane is chlorosilane, H4-aslclm
(a = 1.2.3.4) in a solvent and ammonia N
It is an elastomer obtained by reacting with H, and the method of the present invention includes H, 5iC1, alone or 1
It is preferable to use a mixture of different types of chlorosilanes mainly containing 1 g of 2sfc as a raw material, which is liquid at room temperature. As a solvent during synthesis, benzene, diethyl ether, dichloromethane, tetrahydrofuran, pyridine, etc. can be used, but the structure, composition, and molecular weight of the inorganic polysilazane to be synthesized differ slightly depending on the type of solvent. However, they all consist of hydrogen, nitrogen, and silicon and do not contain carbon. For example, (HzSiNH) x, (HzSiN
Those having a structure such as H) x ((HzSi)+,sN))' are known.
このような無機ポリシラザンを単味もしくは溶剤で希釈
して含浸に供する。溶剤としては、特に制約はないが、
ベンゼン、ジエチルエーテル、ジクロロメタン、テトラ
ヒドロフラン、ピリジンは目的に適う。希釈の場合は炭
素繊維プリフォームの表面積、炭素繊維表面に形成させ
る炭化ケイ素膜の厚さ等によって定まるので一概に決め
られないが、経験的にはおよそ溶剤の割合は０〜８０重
量％とするのがよい。Such inorganic polysilazane is used alone or diluted with a solvent for impregnation. There are no particular restrictions on the solvent, but
Benzene, diethyl ether, dichloromethane, tetrahydrofuran, pyridine are suitable for the purpose. In the case of dilution, it is determined by the surface area of the carbon fiber preform, the thickness of the silicon carbide film formed on the carbon fiber surface, etc., so it cannot be determined definitively, but empirically, the proportion of the solvent should be approximately 0 to 80% by weight. It is better.
含浸方法に関しては、含浸液を炭素繊維プリフォームに
圧入してもよいし、炭素繊維プリフォーム内の空隙を真
空状態にしておいて含浸液を吸入させてもよい。真空脱
気してから圧入しても圧入法は、圧入後高い圧力を一定
時間保持することによって炭素繊維同志の接触部に形成
される狭い間隙に含浸液を十分浸透させることができる
ので圧入法がより好ましい。Regarding the impregnation method, the impregnating liquid may be press-fitted into the carbon fiber preform, or the voids within the carbon fiber preform may be evacuated and the impregnating liquid may be sucked into the carbon fiber preform. Even if the carbon fibers are press-fitted after vacuum degassing, the press-fitting method is not suitable because by maintaining high pressure for a certain period of time after press-fitting, the impregnating liquid can be sufficiently penetrated into the narrow gap formed between the contact parts of the carbon fibers. is more preferable.
圧入する圧力は５ｋｇ／ｃｏ＋”以上５０００ｋｇ／ｃ
ｍ”以下が適当である。５ｋｇ／ｃｍ”未満では繊維接
触部への浸透が十分でない。一方、５０００ｋｇ／ｃｍ
”あれば、実質的に繊維接触部のみならず、繊維自身の
開気孔にも十分浸透しつくす。含浸体を不活性ガス中で
加熱すると、溶剤の蒸発に続いて１５０°Ｃあたりから
無機ポリシラザンの熱分解がはじまるが、６００°Ｃ付
近でほぼ終了して非晶質の窒化ケイ素が得られる。引き
続き、高温下非窒化性雰囲気から非酸化性雰囲気で熱処
理を施こす。非窒化性雰囲気とは、無機ポリシラザンか
ら転化した非晶質の窒化ケイ素を基材の炭素と反応させ
て炭化ケイ素を生成させる際に発生する窒素ガスの放出
を妨げない十分低い窒素分圧を意味する。この上限の窒
素分圧は１３００°Ｃで０．１ａｔｍ、 １９００″Ｃ
で２０ａ ｔｍであり、第１図に斜線で示す範囲内に窒
素分圧を保持する必要がある。The press-fitting pressure is 5kg/co+” or more 5000kg/c
A weight of less than 5 kg/cm is appropriate. If the weight is less than 5 kg/cm, penetration into the fiber contact area is insufficient. On the other hand, 5000kg/cm
If present, the inorganic polysilazane will substantially penetrate not only the fiber contact areas but also the open pores of the fibers themselves. When the impregnated body is heated in an inert gas, following evaporation of the solvent, the inorganic polysilazane thermal decomposition begins, but almost completes at around 600°C to obtain amorphous silicon nitride.Subsequently, heat treatment is performed at high temperature in a non-nitriding atmosphere to a non-oxidizing atmosphere. means a sufficiently low nitrogen partial pressure that does not prevent the release of nitrogen gas generated when silicon carbide is produced by reacting amorphous silicon nitride converted from inorganic polysilazane with carbon in the base material. Nitrogen partial pressure is 0.1 atm at 1300°C, 1900″C
20 atm, and it is necessary to maintain the nitrogen partial pressure within the range shown by diagonal lines in FIG.
非酸化性雰囲気とは酸素ガス、水分等の酸化性ガスを実
質的に含まず、炭化ケイ素の層を形成させる加熱工程に
おいて一酸化ケイ素の生成が無視できる雰囲気をいう。A non-oxidizing atmosphere is an atmosphere that does not substantially contain oxidizing gases such as oxygen gas and moisture, and in which the production of silicon monoxide can be ignored in the heating process for forming a silicon carbide layer.
雰囲気ガスとしてはヘリウム、ネオン、アルゴン等の不
活性ガスあるいは水素ガス等が好ましい。圧力は１０−
４〜１１００ａｔ程度が適当である。非窒化性かつ非酸
化性雰囲気での加熱温度は１３００〜１９００″Ｃが適
当である。１３００°Ｃ未満では反応速度が遅く、実用
的でない。一方、１９．００°Ｃを越えると雰囲気中に
不可避的に混入している微量の酸素によりケイ素が一酸
化ケイ素ガスとして揮散する現象が無視できなくなる。The atmospheric gas is preferably an inert gas such as helium, neon, or argon, or hydrogen gas. The pressure is 10-
Approximately 4 to 1100 at is appropriate. The appropriate heating temperature in a non-nitriding and non-oxidizing atmosphere is 1300 to 1900''C. Below 1300°C, the reaction rate is slow and impractical. On the other hand, if it exceeds 19.00°C, no The phenomenon of silicon volatilizing as silicon monoxide gas cannot be ignored due to the trace amount of oxygen that is inevitably mixed in.
このためケイ素の損失が大きくなる。Therefore, silicon loss increases.
加熱時間は炭化ケイ素の層を形成させるのに充分な時間
があればよ＜ １３００°Ｃでは５〜２０時間程度・１
９００″Ｃでは０．５〜５時間程度でよい。The heating time should be enough time to form a layer of silicon carbide (about 5 to 20 hours at 1300°C)
At 900″C, it may take about 0.5 to 5 hours.
炭素焼結体に無機ポリシラザンを被覆して非窒化性かつ
非酸化性雰囲気で加熱することにより、下記の反応が起
こり、炭素焼結体表面の炭素が反応して炭化ケイ素の被
膜を形成する。By coating a carbon sintered body with inorganic polysilazane and heating it in a non-nitriding and non-oxidizing atmosphere, the following reaction occurs, and carbon on the surface of the carbon sintered body reacts to form a silicon carbide film.
ＳｉＮｘ＋Ｃ−３ｉＣ＋（Ｘ／２）Ｎｚｊ〔実施例〕
実施例１
直径７ｎのＰＮＮ系長繊維を２次元に織成して積層して
、厚さ２．８鵬、嵩密度０．７２ｇ／ａＡ、１００ｍｍ
角のシートを得た。これをジクロロメタンに浸漬し、２
４時間放置後乾燥した。このプリフォームをシリコーン
ゴムの容器中で真空脱気して１０− ”Ｔｏｒｒ到達さ
せた。液状の無機ポリシラザンを容器に導入して含浸さ
せた。このゴム容器をシリコーンゴムの蓋で封入し、冷
間静水圧プレスでゴム容器の外側から５０００ｋｇ／ｃ
−の圧力をかけたのち、処理物を取出して含浸体を得た
。これを加熱炉で１０″Ｃ／＋ｉｎの昇温速度で６００
″Ｃまで上げ１時間保持後放冷した。SiNx+C-3iC+(X/2)Nzz [Example] Example 1 PNN long fibers with a diameter of 7n were two-dimensionally woven and laminated to have a thickness of 2.8mm, a bulk density of 0.72g/aA, and 100mm.
Got a corner sheet. Soak this in dichloromethane and
It was left to stand for 4 hours and then dried. The preform was vacuum degassed to 10-'' Torr in a silicone rubber container. Liquid inorganic polysilazane was introduced into the container and impregnated. The rubber container was sealed with a silicone rubber lid and cooled. 5000kg/c from the outside of the rubber container using a hydrostatic press
After applying a pressure of -, the treated product was taken out to obtain an impregnated body. Heat this in a heating furnace at a heating rate of 10"C/+in.
The temperature was raised to "C", held for 1 hour, and then allowed to cool.
続いて、焼結炉に入れて常圧のアルゴン雰囲気で１５０
０°Ｃまで３０°Ｃ／ｍｉｎで昇温し、５時間保持後放
冷して多孔質焼結体を得た。この焼結体は嵩密度０．８
９ｇ／ａｉ！であり、１２００°Ｃ２１００時間空気雰
囲気に保持してもわずかに０．３１重量％の重量増加が
見られたのみであった。Next, it was placed in a sintering furnace and heated for 150 minutes in an argon atmosphere at normal pressure.
The temperature was raised to 0°C at a rate of 30°C/min, maintained for 5 hours, and then allowed to cool to obtain a porous sintered body. This sintered body has a bulk density of 0.8
9g/ai! Even after being held in an air atmosphere at 1200°C for 2100 hours, a slight weight increase of 0.31% by weight was observed.
実施例２
直径７ｎ、平均長さ５０ｕｍのＰＡＮ系短繊維を５体積
％となるようにジクロロメタン中に超音波を使用して分
散させ、直ちに５０〜２００μｍの連通孔を有する樹脂
製、直径３０ｍｍの多孔円板を挿入したダイスに鋳込ん
だ。ラムで上部より２００ ｋｇ ／ ｃｉで加圧して
ジクロロメタンを多孔円板を通して絞り出した。これを
取出して乾燥し、厚さ３閣、直径３０ｍｍのプリフォー
ムを得た。嵩密度は０．８１ｇ／ｃｆｆｌであった。一
方、液状の無機ポリシラザン８０重量部をジクロロメタ
ン２０重量部に溶解して含浸液を調製した。Example 2 PAN short fibers with a diameter of 7 nm and an average length of 50 um were dispersed in dichloromethane using ultrasound to a concentration of 5% by volume, and immediately dispersed into a resin-made, 30 mm diameter fiber having communicating pores of 50 to 200 μm. It was cast into a die into which a perforated disc was inserted. A pressure of 200 kg/ci was applied from the top using a ram, and dichloromethane was squeezed out through the perforated disk. This was taken out and dried to obtain a preform with a thickness of 3 mm and a diameter of 30 mm. The bulk density was 0.81 g/cffl. On the other hand, an impregnating solution was prepared by dissolving 80 parts by weight of liquid inorganic polysilazane in 20 parts by weight of dichloromethane.
前記プリフォームをシリコーンゴムの容器に入れて真空
脱気し１０− ”Ｔｏｒｒ到達させた。含浸液を容器に
導入してプリフォーム内部に含浸させた。このゴム容器
をシリコーンゴムの蓋で封入し、冷間静水圧プレスでゴ
ム容器の外側より５０００ｋｇ／ｃｍ”の圧力をかけた
のち処理物を取出して含浸体を得た。The preform was placed in a silicone rubber container and vacuum degassed to reach 10-'' Torr. The impregnating liquid was introduced into the container and impregnated inside the preform. This rubber container was sealed with a silicone rubber lid. After applying a pressure of 5000 kg/cm'' from the outside of the rubber container using a cold isostatic press, the treated product was taken out to obtain an impregnated body.
これを加熱炉で１０°Ｃ／ｍｉｎの昇温速度で１００°
Ｃまで上げ１時間保持後再び６００°Ｃまで上げ１時間
保持後放冷した。続いて、焼結炉に入れ常圧のアルゴン
雰囲気で１５００°Ｃまで３０°Ｃ／ｗｉｎで昇温し５
時間保持後放冷して多孔質焼結体を得た。この焼結体の
密度は１．０２ｇ／ｃｎであり、１２００″Ｃ１１００
時間空気雰囲気中に保持してもわずかに０．２５重量％
の重量％の重量増加が見られただけであった。This is heated to 100° in a heating furnace at a heating rate of 10°C/min.
After raising the temperature to 600°C and holding it for 1 hour, the temperature was raised again to 600°C and held for 1 hour, and then allowed to cool. Next, it was placed in a sintering furnace and heated to 1500°C at a rate of 30°C/win in an argon atmosphere at normal pressure.
After holding for a time, the mixture was allowed to cool to obtain a porous sintered body. The density of this sintered body is 1.02g/cn, and the density is 1200″C1100
Only 0.25% by weight even if kept in air atmosphere for hours
A weight increase of only % by weight was observed.
以上のように、この発明によれば、液状の無機ポリシラ
ザンにより炭素繊維表面に均一に被覆膜を形威し、炭素
との反応によって表層炭素を炭化ケイ素に転化できるの
で従来の炭素繊維上に炭化ケイ素膜を積層させる方法と
は異なり、炭化ケイ素膜の剥離や、亀裂が起きにくい。As described above, according to the present invention, a coating film can be uniformly formed on the surface of carbon fibers using liquid inorganic polysilazane, and surface carbon can be converted into silicon carbide by reaction with carbon, so that it can be used on conventional carbon fibers. Unlike the method of laminating silicon carbide films, this method is less likely to cause peeling or cracking of the silicon carbide film.
このため１０００°Ｃを越える空気中でも炭素の燃焼損
耗は完全に防止され、逆に表層の炭化ケイ素の酸化被膜
形成によるわずかに重量増が見られるのみである、この
方法によれば炭素が本来持つ耐熱性に加え耐酸化性の良
好な１０００’Ｃ以上の高温での使用に耐える多孔体の
製造が可能となる。For this reason, combustion loss of carbon is completely prevented even in air at temperatures exceeding 1000°C, and on the contrary, only a slight increase in weight is observed due to the formation of an oxide film on the silicon carbide on the surface. It becomes possible to produce a porous body that has good oxidation resistance in addition to heat resistance and can withstand use at high temperatures of 1000'C or higher.
第１図は非窒化性雰囲気を達成しうる窒素分圧と加熱温
度との関係を示すグラフである。FIG. 1 is a graph showing the relationship between nitrogen partial pressure and heating temperature that can achieve a non-nitriding atmosphere.
Claims (1)
非窒化性かつ非酸化性雰囲気で加熱して炭素繊維表面の
炭素を無機ポリシラザン中のケイ素と反応させて炭化ケ
イ素に転化することを特徴とする炭素と炭化ケイ素から
なる多孔体の製造方法Impregnating the carbon fiber preform with inorganic polysilazane,
A method for producing a porous body made of carbon and silicon carbide, characterized by heating in a non-nitriding and non-oxidizing atmosphere to react carbon on the surface of carbon fibers with silicon in inorganic polysilazane and converting it into silicon carbide.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19793589A JPH0365574A (en) | 1989-08-01 | 1989-08-01 | Production of porous material comprising carbon and silicon carbide |
| US07/554,697 US5114749A (en) | 1989-08-01 | 1990-07-18 | Method for manufacturing carbon material having good resistance to oxidation by coating the carbon material with an inorganic polysilazane and then heating |
| EP90114770A EP0411611A1 (en) | 1989-08-01 | 1990-08-01 | Method for manufacturing carbon material good in resistance to oxidation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19793589A JPH0365574A (en) | 1989-08-01 | 1989-08-01 | Production of porous material comprising carbon and silicon carbide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0365574A true JPH0365574A (en) | 1991-03-20 |
Family
ID=16382741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19793589A Pending JPH0365574A (en) | 1989-08-01 | 1989-08-01 | Production of porous material comprising carbon and silicon carbide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0365574A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013536150A (en) * | 2010-08-27 | 2013-09-19 | コミッサリア タ レネルジー アトミク エ オ エネルジー オルタネイティヴ | Crucible for solidifying silicon ingot |
-
1989
- 1989-08-01 JP JP19793589A patent/JPH0365574A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013536150A (en) * | 2010-08-27 | 2013-09-19 | コミッサリア タ レネルジー アトミク エ オ エネルジー オルタネイティヴ | Crucible for solidifying silicon ingot |
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