JPH0522678B2 - - Google Patents
Info
- Publication number
- JPH0522678B2 JPH0522678B2 JP59221985A JP22198584A JPH0522678B2 JP H0522678 B2 JPH0522678 B2 JP H0522678B2 JP 59221985 A JP59221985 A JP 59221985A JP 22198584 A JP22198584 A JP 22198584A JP H0522678 B2 JPH0522678 B2 JP H0522678B2
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- containing composition
- heating
- whiskers
- silicon carbide
- 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.)
- Expired - Lifetime
Links
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 88
- 229910052799 carbon Inorganic materials 0.000 claims description 86
- 239000000203 mixture Substances 0.000 claims description 83
- 238000010438 heat treatment Methods 0.000 claims description 59
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical class [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 43
- 150000003377 silicon compounds Chemical class 0.000 claims description 17
- 239000000443 aerosol Substances 0.000 claims description 16
- 150000001722 carbon compounds Chemical class 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 15
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 239000003575 carbonaceous material Substances 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 229920002678 cellulose Polymers 0.000 claims description 5
- 239000001913 cellulose Substances 0.000 claims description 5
- 238000000926 separation method Methods 0.000 claims description 5
- 150000001340 alkali metals Chemical class 0.000 claims description 3
- 229910001508 alkali metal halide Inorganic materials 0.000 claims description 2
- 229910001615 alkaline earth metal halide Inorganic materials 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 24
- 229910010271 silicon carbide Inorganic materials 0.000 description 24
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Inorganic materials [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 21
- 239000013078 crystal Substances 0.000 description 18
- 239000012298 atmosphere Substances 0.000 description 13
- 235000013339 cereals Nutrition 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 241000209094 Oryza Species 0.000 description 9
- 235000007164 Oryza sativa Nutrition 0.000 description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 9
- 239000002655 kraft paper Substances 0.000 description 9
- 239000000123 paper Substances 0.000 description 9
- 235000009566 rice Nutrition 0.000 description 9
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 8
- 239000006227 byproduct Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 7
- 238000002156 mixing Methods 0.000 description 7
- 229910052710 silicon Inorganic materials 0.000 description 7
- 239000010703 silicon Substances 0.000 description 7
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 230000008859 change Effects 0.000 description 6
- 238000002485 combustion reaction Methods 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 238000001000 micrograph Methods 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 238000000634 powder X-ray diffraction Methods 0.000 description 6
- 238000010183 spectrum analysis Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 230000005484 gravity Effects 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 230000002950 deficient Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000635 electron micrograph Methods 0.000 description 4
- 239000000295 fuel oil Substances 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 235000019198 oils Nutrition 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000001294 propane Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000011800 void material Substances 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 229910003902 SiCl 4 Inorganic materials 0.000 description 3
- -1 SiCl4 Chemical class 0.000 description 3
- 239000002585 base Substances 0.000 description 3
- 238000003763 carbonization Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000011049 filling Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910001507 metal halide Inorganic materials 0.000 description 3
- 150000005309 metal halides Chemical class 0.000 description 3
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- GWHJZXXIDMPWGX-UHFFFAOYSA-N 1,2,4-trimethylbenzene Chemical compound CC1=CC=C(C)C(C)=C1 GWHJZXXIDMPWGX-UHFFFAOYSA-N 0.000 description 2
- UJOBWOGCFQCDNV-UHFFFAOYSA-N 9H-carbazole Chemical compound C1=CC=C2C3=CC=CC=C3NC2=C1 UJOBWOGCFQCDNV-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 2
- YNQLUTRBYVCPMQ-UHFFFAOYSA-N Ethylbenzene Chemical compound CCC1=CC=CC=C1 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 2
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 2
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- SMWDFEZZVXVKRB-UHFFFAOYSA-N Quinoline Chemical compound N1=CC=CC2=CC=CC=C21 SMWDFEZZVXVKRB-UHFFFAOYSA-N 0.000 description 2
- 229910018557 Si O Inorganic materials 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 2
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Chemical compound C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 229910002090 carbon oxide Inorganic materials 0.000 description 2
- 238000010000 carbonizing Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000003610 charcoal Substances 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 230000008602 contraction Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000005485 electric heating Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 150000004820 halides Chemical class 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 239000003350 kerosene Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000012744 reinforcing agent Substances 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 2
- PRAKJMSDJKAYCZ-UHFFFAOYSA-N squalane Chemical compound CC(C)CCCC(C)CCCC(C)CCCCC(C)CCCC(C)CCCC(C)C PRAKJMSDJKAYCZ-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000011269 tar Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 239000008096 xylene Substances 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- HECLRDQVFMWTQS-RGOKHQFPSA-N 1755-01-7 Chemical compound C1[C@H]2[C@@H]3CC=C[C@@H]3[C@@H]1C=C2 HECLRDQVFMWTQS-RGOKHQFPSA-N 0.000 description 1
- WHRZCXAVMTUTDD-UHFFFAOYSA-N 1h-furo[2,3-d]pyrimidin-2-one Chemical compound N1C(=O)N=C2OC=CC2=C1 WHRZCXAVMTUTDD-UHFFFAOYSA-N 0.000 description 1
- FXNDIJDIPNCZQJ-UHFFFAOYSA-N 2,4,4-trimethylpent-1-ene Chemical group CC(=C)CC(C)(C)C FXNDIJDIPNCZQJ-UHFFFAOYSA-N 0.000 description 1
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 description 1
- BSKHPKMHTQYZBB-UHFFFAOYSA-N 2-methylpyridine Chemical compound CC1=CC=CC=N1 BSKHPKMHTQYZBB-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 1
- 244000073231 Larrea tridentata Species 0.000 description 1
- 235000006173 Larrea tridentata Nutrition 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 244000046052 Phaseolus vulgaris Species 0.000 description 1
- 235000010627 Phaseolus vulgaris Nutrition 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 235000019484 Rapeseed oil Nutrition 0.000 description 1
- 229910003910 SiCl4 Inorganic materials 0.000 description 1
- 229910004014 SiF4 Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000004996 alkyl benzenes Chemical class 0.000 description 1
- XYLMUPLGERFSHI-UHFFFAOYSA-N alpha-Methylstyrene Chemical compound CC(=C)C1=CC=CC=C1 XYLMUPLGERFSHI-UHFFFAOYSA-N 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 235000015278 beef Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 239000004359 castor oil Substances 0.000 description 1
- 235000019438 castor oil Nutrition 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- SLLGVCUQYRMELA-UHFFFAOYSA-N chlorosilicon Chemical compound Cl[Si] SLLGVCUQYRMELA-UHFFFAOYSA-N 0.000 description 1
- 239000003240 coconut oil Substances 0.000 description 1
- 235000019864 coconut oil Nutrition 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 235000012343 cottonseed oil Nutrition 0.000 description 1
- 239000002385 cottonseed oil Substances 0.000 description 1
- 229960002126 creosote Drugs 0.000 description 1
- 229930003836 cresol Natural products 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000012717 electrostatic precipitator Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000000227 grinding Methods 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
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 239000000944 linseed oil Substances 0.000 description 1
- 235000021388 linseed oil Nutrition 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- AUHZEENZYGFFBQ-UHFFFAOYSA-N mesitylene Substances CC1=CC(C)=CC(C)=C1 AUHZEENZYGFFBQ-UHFFFAOYSA-N 0.000 description 1
- 125000001827 mesitylenyl group Chemical group [H]C1=C(C(*)=C(C([H])=C1C([H])([H])[H])C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- JLUFWMXJHAVVNN-UHFFFAOYSA-N methyltrichlorosilane Chemical compound C[Si](Cl)(Cl)Cl JLUFWMXJHAVVNN-UHFFFAOYSA-N 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- JXTPJDDICSTXJX-UHFFFAOYSA-N n-Triacontane Natural products CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC JXTPJDDICSTXJX-UHFFFAOYSA-N 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 235000014593 oils and fats Nutrition 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 239000011087 paperboard Substances 0.000 description 1
- 239000012188 paraffin wax Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 description 1
- ABTOQLMXBSRXSM-UHFFFAOYSA-N silicon tetrafluoride Chemical compound F[Si](F)(F)F ABTOQLMXBSRXSM-UHFFFAOYSA-N 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 229940032094 squalane Drugs 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 239000003760 tallow Substances 0.000 description 1
- 239000011289 tar acid Substances 0.000 description 1
- 239000002383 tung oil Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000010698 whale oil Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 125000002256 xylenyl group Chemical class C1(C(C=CC=C1)C)(C)* 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/005—Growth of whiskers or needles
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
Description
〔技術分野〕
本発明は炭化ケイ素ウイスカーの新規な製造法
に関するものである。
〔従来技術〕
炭化ケイ素ウイスカーを製造する従来の技術と
しては、SiCl4などのケイ素化合物とトルエン
（C7H8）、CCl4などの炭素化合物の蒸気を水素気
流によつて高温雰囲気の反応器に搬送し、気相で
反応させた後反応器の下流側の低温部に析出させ
て得る方法が知られている（例えば、日本金属学
会編「結晶成長」、（昭50.3.30）、丸善、p354）。
しかしながらこの方法では、ケイ素化合物が少
なからずそのままガス状態で反応の系外に揮散す
る点と、大量の水素の供給を必要とする問題点が
あり、またウイスカーの析出設備は小型のバツチ
方式から工業的な大型化にすることが困難な欠点
があつた。
また固体の原料から炭化ケイ素ウイスカーを製
造する方法としては、もみ穀を一酸化炭素雰囲気
下で加熱する方法（特開昭53−113300）、もみ穀
を一旦加熱して得られる炭化されたもみ穀を再度
非酸化性雰囲気中で加熱する方法（特開昭58−
20799）、もみ穀を燃焼させて得られる灰化物にカ
ーボンブラツクを混合した後、非酸化性雰囲気で
加熱する方法（特開昭58−45195）などが知られ
ている。
しかしながら、農業副産物であるもみ穀は、そ
の性状が天候や産出地あるいは品種などによつて
異なり、また採取、運搬過程で種々雑多の不純物
や異物が混入し易いため、得られる炭化ケイ素ウ
イスカーの品質が安定し難いといつた欠点があ
る。またもみ穀を加熱する方法では、得られた炭
化ケイ素ウイスカーのほぼ２倍の重量割合で微粒
子状の炭化ケイ素結晶が、もみ穀の炭化物やもみ
穀の灰化物とカーボンブラツクの混合物を加熱す
る方法では同程度の重合割合で微粒子状の炭化ケ
イ素結晶が同時に副生し、ウイスカーと微粒子状
結晶との混合状態で得られるので、高収率でウイ
スカーを得ることが出来ず、更に、この混合状態
からウイスカーのみを分離して取り出すことは容
易ではなく、分離操作を行なつた後にも微粒子状
結晶が少なからずウイスカー中に残存するため、
これを金属やセラミツクスなどに加えてこれらを
補強する目的に関しては、充分に満足できる結果
は得られにくいという欠点がある。
本発明者らはこれら従来技術の得失を検討した
結果、先に特開昭59−121198号として、水蒸気を
含む熱ガス中に分解性ケイ素化合物及び炭素化合
物を装入・分解して、ケイ素酸化物及び単体炭素
のそれぞれのエーロゾルを含む混合エーロゾル分
散質を生成せしめ、該生成した分散質を固−気分
離操作により捕集して得た嵩比重が0.2ｇ／c.c.以
下の含炭素組成物を加熱することにより、炭化ケ
イ素ウイスカーを製造する方法を提案した。この
方法はなんら機械的な粉砕や混合操作を行うこと
なくきわめて高純度で品質の一定した含炭素組成
物を連続的に得ることが出来、かつ該含炭素組成
物を加熱することにより微粒子状結晶を殆んど副
生させずに炭化ケイ素ウイスカーのみを生成させ
ることが出来るといつた原理的にきわめて画期的
な方法である。
しかしながら、この方法は上述のごとく、原理
的、本質的に優れた方法ではあるが、これを工業
的規模の装置に適用して実施しようとした場合、
たとえば含炭素組成物を加熱するための電気炉等
の加熱設備を実験室的規模から工業的な水準に大
型化しようとした場合、単に被加熱体の占める空
間容積を大きくし、含炭素組成物の充填量を増や
す方法では真直ぐに成長した長さや太さが均等
で、形状の均一性に優れたウイスカーのほかに、
短く、湾曲の多い、ふぞろいな不良品のウイスカ
ーもかなり副生混入するという問題があることが
わかつた。
即ち含炭素組成物を電気炉等で加熱した場合、
反応の進行とともに反応生成物で占める見掛けの
容積は、仕込み時の見掛け容積の半分以下に急激
に減少し、該収縮によつて生じた空隙に面する厚
さ約10mmの外側の部分には長く、真直ぐに成長し
た良好なウイスカーが生成するが、その内側には
比較的短かく、湾曲の多い不良品が生成すると推
定されるのである。
本発明者らは、このような推論をもとに鋭意検
討を積み重ねた結果、先に提案した特開昭59−
121198号公報の方法（以下基本方法という）を改
良する方法として、含炭素組成物を加熱するに当
り、加熱部に連続的な空隙部を有する通気性構造
体を形成し、該含炭素組成物が該構造体空隙部に
充填された状態で該加熱を行なう方法を新たに提
案した（特願昭59−137091号、以下改良方法とい
う）。ここで通気性構造体が円柱、円筒などの形
状の小片を構造単位としたものであれば、含炭素
組成物とそれら小片とを単に機械的に混合した
後、この混合物を加熱炉内に装入することによつ
て、含炭素組成物が通気性構造体の空隙部に充填
された状態で加熱することができる。またここで
小片の素材をセルロース質を主成分とする素材、
いわゆる紙としておけば、加工が容易で価格が安
く燃焼除去が可能であるなどの点で工業的に極め
て有利である。
以上のごとく改良方法に従つて通気性構造体の
共存下で含炭素組成物を加熱すれば、基本方法に
おける短く湾曲の多い不良品のウイスカーが副生
混入するといつた問題は著しく減少させることが
でき、生成するウイスカーの殆んどは長く真直ぐ
に成長した形状となつた。しかしながらそれらの
長さの分布に関しては完全に満足できるというこ
とではなく、条件によつては平均の長さの５倍に
達するものや３分の１以下のものも生成する場合
があり、また短く湾曲の多い不良品のウイスカー
も若干ながら副生する場合もある。
これらの原因として、本発明者らは、次の如く
推察した。即ち通気性構造体の素材を紙とした場
合、紙が加熱されることによつて熱分解を経て炭
化に至つた状態では、元の寸法に対して一辺が10
〜35％収縮する。この収縮によつて、含炭素組成
物と通気性構造体を構成する小片との混合物にお
いては、その内部あるいは外周部に空隙が発生
し、また一方で小片の収縮に伴う圧縮力によつて
含炭素組成物の一部は圧密化され、このようにし
て含炭素組成物の位置によつて通気性に不均一性
が生じる場合があるためと推察されるのである。
〔発明の目的〕
本発明の目的は、基本方法およびその改良方法
をさらに改良し、その本来の効果を一層効果的か
つ再現性良く奏することのできる方法を提供する
ことである。
本発明の他の目的は、かかる基本方法を特に工
業的規模で実施する場合に適した方法を提供する
ことである。
本発明のさらに他の目的は、基本方法を特に工
業的規模で実施する場合においても、長さや太さ
が均一で、形状の均一性に優れたウイスカーを製
造する方法を提供することである。
本発明のさらに他の目的は以下の記載から明ら
かになるであろう。
〔発明の開示〕
本発明者らは上記点に鑑み鋭意検討を重ねた結
果、含炭素組成物に通気性構造体を共存させて加
熱する炭化ケイ素ウイスカーの製造法において通
気性構造体を形成する素材を薄肉の炭素質物質と
すれば、加熱によつて通気性構造体は寸法に変化
が生じることなく、この結果生成するウイスカー
の形状は加熱位置によらず格段に均等になり、長
さの分布は著しく狭くなり、かつ短く、湾曲した
ものはほとんど生成しなくなる現象を見い出し本
発明に至つた。
即ち、本発明に従つて、水蒸気を含む熱ガス中
に分解性ケイ素化合物及び炭素化合物を装入・分
解して、ケイ素酸化物及び単体炭素のそれぞれの
エーロゾルを含む混合エーロゾル分数質を生成せ
しめ、該生成した分散質を固−気分離操作により
捕集して得た嵩密度が0.2ｇ／c.c.以下の含炭素組
成物を1300〜1800℃に加熱するに当り、該加熱部
に、連続的な空隙部を有する通気性構造体を形成
し、該含炭素組成物が、該構造体空隙部に充填さ
れた状態で該加熱を行う炭化ケイ素ウイスカーの
製造方法において、通気性構造体を形成する素材
が薄肉の炭素質物質好ましくは主成分がセルロー
ス質である薄肉の物質の炭化物であることを特徴
とする炭化ケイ素ウイスカーの製造方法が提供さ
れる。
〔発明の詳細な開示〕
以下本発明を詳しく説明する。本発明で使用す
る含炭素組成物についていえば、まず、単体炭素
のエーロゾルは、分解性の炭素化合物を熱ガス中
に装入して容易に得ることができる。他方ケイ素
酸化物のエーロゾルは、例えばSiCl4の如き分解
性のケイ素化合物を水蒸気を含む熱ガス中に装入
すると、加水分解あるいは酸化により得ることが
できる。容易に理解できるように、水蒸気を含む
熱ガス中に分解性の炭素化合物及び分解性のケイ
素化合物を同時に装入すれば、直ちに単体炭素と
ケイ素酸化物を含む混合エーロゾルとなる。
本発明で使用しうる分解性のケイ素化合物とし
ては、一般式SioX2o+2（ｎは１から４の整数）で
表わされるもので、Ｘは水素もしくはハロゲン原
子またはアルキル基もしくはアルコキシル基であ
り、かかる具体的なケイ素化合物を挙げれば
SiCl4，HSiCl3，SiH4，Si2H6，（CH3）4Si，
（CH3）2SiCl2，CH3SiCl3，SiF4，Si（OC2H5）4な
どである。これらは単独でまたは混合物として使
用される。
本発明の実施に用いる分解性炭素化合物とは、
後に述べるような熱ガス中に装入された場合、容
易に分解して単体炭素を生成しうるようなもの
で、そのままで気相もしくは液相状態か、昇温に
より容易に液相状態になり得るものが好適に使用
可能である。例えばLPG、ナフサ、ガソリン、
燃料油、灯油、軽油、重油、潤滑油、流動パラフ
インなどの石油製品類；メタン、エタン、プロパ
ン、ブタン、ペンタン、メタノール、エタノー
ル、プロパノール、エチレン、アセチレン、ｎ−
パラフイン、ブタジエン、イソプレン、イソブチ
レン、ベンゼン、トルエン、キシレン、シクロヘ
キサン、シクロヘキセン、ジシクロペンタジエ
ン、エチルベンゼン、スチレン、キユメン、プソ
イドクメン、メシチレン、アルキルベンゼン、α
−メチルスチレン、ジシクロドデカトリエン、ジ
イソブチレン、塩化ビニル、クロルベンゼン、
C9溜分混合物、エチレンボトムなどの石油化学
製品類；タール、ピツチ、クレオソート油、ナフ
タリン、アントラセン、カルバゾール、タール
酸、フエノール、クレゾール、キシレノール、ピ
リジン、ピコリン、キノリンなどのタール製品
類；大豆油、ヤシ油、アマニ油、綿実油、ナタネ
油、キリ油、ヒマシ油、鯨油、牛脂、スクワラ
ン、オレイン酸、ステアリン酸などの油脂類など
がある。
本発明ではかかる分解性炭素化合物は炭素の供
給が目的であるから、その種類は広範囲に選択可
能である。しかしながら取扱いの簡便さ、炭素収
率の面からトルエン、キシレン、ベンゼン、灯
油、軽油、重油、C9溜分混合物、エチレンボト
ムなどが好ましい。
これらを水蒸気を含む熱ガス中で分解して本発
明に用いる微細な含炭素組成物を得るには炉を用
いるのが好適である。この炉には加熱装置及びケ
イ素化合物、炭素化合物の装入用ノズルと、ガス
装入ダクト、混合エーロゾイル排出ダクトとが具
備されており、加熱装置としては燃焼バーナー、
通電発熱体などがあるが、燃焼バーナーが簡便で
あり、また熱効率の面でも好ましい。第３図はこ
れに用いる炉の１例を示すものである。この炉内
には少なくとも600℃以上の空隙領域がなければ
ならない。この温度以上であれば炭素化合物から
は単体炭素が、更に水蒸気を含む雰囲気下でケイ
素化合物からはケイ素酸化物が得られ、気体とこ
れら固形物との混合体である混合エーロゾル状態
を発生する。
水蒸気を含む熱ガスを得る方法としては、通電
発熱方式、高周波加熱方式、放電方式によつて得
た熱ガス中に水蒸気を注入することによつても得
ることができるが、水素、メタン、エタン、プロ
パンなどあるいは原料とする炭化水素のように燃
焼して水蒸気を生成する可燃物を空気で燃焼させ
る方法が装置上で簡便であり、熱効率の面から経
済的である。
本発明の実施に用いられるケイ素化合物は、水
蒸気を含む熱ガス中で加水分解反応によつてケイ
素酸化物の固形物に変化する性質に加えて、酸化
あるいは熱分解反応によつてケイ素酸化物に変化
する性質を有し、しかもこれらの反応はきわめて
速く0.1〜0.5秒程度で完結するので、反応帯域に
おける滞溜時間を１〜10秒程度とすれば熱と水蒸
気が共存する雰囲気下では、ケイ素化合物が未反
応のガス状態のままで反応の系外に揮散すること
はほとんどない。
以上のごとくして得られた混合エーロゾルは、
炉の外に排出誘導した後、該エーロゾルに含有さ
れている固形物分散質をバグフイルター、サイク
ロン、電気集塵機等の捕集装置で固−気分離操作
を施して捕集する。かくして捕集された含炭素組
成物は、本発明の通気性構造体の共存下で1300〜
1800℃好ましくは1400〜1600℃に加熱することに
よつて炭化ケイ素ウイスカーとすることができ
る。
本発明は以上のごとくして得られた含炭素組成
物を加熱して炭化ケイ素ウイスカーとするに当
り、該加熱部に、連続的な空隙部を有する通気性
構造体を形成し、該含炭素組成物が、該構造体空
隙部に充填された状態で該加熱を行うことを特徴
とするものである。
本発明で言う通気性構造体とは、下記のごとき
立体的形状の小片を構造単位としこれを多数個積
み重ねることによつて保持された、通気が可能な
連続的な空隙部を形成した三次元的な構造体であ
つて、該連続した空隙部が1300〜1800℃の加熱に
よつても保持される様な薄肉の炭素質物質を意味
する。構造単位たる立体的小片の形状としては、
円柱、円筒、円錐、球、三角柱、三角錐、立方
体、四角柱、四角錐、テトラポツト形あるいはヒ
モ状などが好適であり、それらの大きさは円柱、
円錐、三角柱などの場合、底面積は0.1〜20cm2好
ましくは0.5〜５cm2、高さは0.2〜10cm好ましくは
0.5〜５cmが好適であり、ヒモ状の場合、巾は0.1
〜５cm好ましくは0.2〜２cm、長さは0.5〜20cm好
ましくは１〜10cmが好適である。
第４図は上記のごとき通気性構造体を形成する
ための構造単位たる小片の形状の一例を念のため
図示したものであるが、イ〜ヘのごとき規則的な
形状のものに限られず、トに示した馬の鞍形状の
ものチに示したテラレツト状のものさらにはリ長
いひも、ヌ短いひも状のものなどいずれでもよ
い。これらはその一種類あるいは２種類以上を規
則的にあるいは不規則に多数個積み重ねることに
よつて、容易に理解されるように、連続的な空隙
部を有する通気性構造体は容易に形成される。
この様に形成された構造体空隙部に含炭素組成
物を充填するには、まず、構造単位小片を規則的
もしくは不規則的に充填してから、含炭素組成物
を加えて該空隙部に流入せしめてもよいし、構造
単位小片と該組成物を充分混合してから充填層を
形成してもよい。
後者の方法を採用した場合、含炭素組成物はこ
れら多数個の小片が構成する通気性構造体の共存
下で、言い換えれば含炭素組成物と多数個の小片
を混合し、これを加熱炉内に充填した状態が、多
数個の小片を積み重ねたことによつて生じる空隙
に含炭素組成物が共存する状態で、1300〜1800℃
に加熱することによつて均一な形状の炭化ケイ素
ウイスカーを得ることができる。ここで、小片の
形状としては例えば円筒とし、小片の内部も連続
的な空隙とすれば、加熱炉内で含炭素組成物が占
める充填可能容積をさ程低下させずに済む。
含炭素組成物と通気性構造体を構成する構造単
位たる小片とを混合する装置も、混合過程で含炭
素組成物が圧密化を生じにくい装置、例えば二重
円スイ型、Ｖ型、リボン型などの混合機、あるい
は気流式浮遊混合機などが適する。ここで、小片
の重量が大きければこの混合過程で含炭素組成物
が圧密化され易く、このため小片は重量の軽い薄
肉状であることが好ましい。
小片の材料としては炭素質物質が好適である。
その理由は炭素質物質は1300〜1800℃の加熱によ
つても寸法や形状にほとんど変化がなく、加熱前
の状態のままの空隙を保つことができるためであ
る。
炭素質物質としては数ミリメートルかあるいは
それ以下の厚みの黒鉛、木炭、炭化した樹脂成形
体あるいは炭化した木材なども好適に使用可能で
あるが、さらに望ましくはセルロース質をその主
成分とする素材、いわゆる洋紙、板紙などの紙で
上記構造単位小片を形成しその形状を保持したま
ま炭化せしめたものが好適である。けだし紙はそ
れ自身が薄肉の物質であり、また他の素材に比較
して種々の形状に加工することが容易であり、さ
らに価格も安いためである。
これら紙（で形成した構造単位小片）は、不活
性ガス雰囲気中で300℃以上好ましくは450℃以上
で５分間以上加熱すれば元の形状をほぼ保持した
まま薄肉の炭状となる。この場合、寸法は加熱す
る前に比較して10〜35％の収縮が生じるが形状は
ほぼ原形をとどめており、このような加熱によつ
て一旦炭化したものは再び炭化ケイ素ウイスカー
の得られる温度である1300〜1800℃に再び加熱し
ても寸法や形状はほとんど全く変化がないのであ
る。
通気性構造体と共存する含炭素組成物の嵩密度
は、加熱する前の状態で0.2ｇ／c.c.以下、好まし
くは0.15ｇ／c.c.以下が必要である。これは嵩密度
が0.2ｇ／c.c.を越えると、加熱して得られる炭化
ケイ素が粒状あるいは湾曲した形状となり易い傾
向が急激に増大するという、本発明者らの実験的
知見に基づくものである。
以上のごとく嵩密度が0.2ｇ／c.c.以下の炭素組
成物を通気性構造体の共存下で加熱することによ
つて、形状の均一な炭化ケイ素ウイスカーを得る
ことができるが、ここでLiF，LiCl，NaF，
NaCl，NaBr，KF，KCl，KBr，MgF2，
MgCl2，CaF2，CaCl2などのアルカリ金属または
アルカリ土類金属のハロゲン化物を含炭素組成物
に添加して加熱することにより、より長いウイス
カーを得ることができる。これらアルカリ金属等
のハロゲン化物の添加割合は、含炭素組成物中の
ケイ素酸化物１モルに対して0.3〜３モル、より
好ましくは0.5〜２モルが好適であり、添加しな
い場合に比較して長さが２〜５倍となる効果が認
められる。添加方法としては上記の二重円スイ型
などの混合機を用いて含炭素組成物と混合する
か、あるいは加熱炉の底部に敷くことでもよい。
含炭素組成物中のケイ素酸化物に対する炭素の
割合は、Ｃ／Si（式量比：ｇ−アトムＣ／ｇ−ア
トムSiをいう。以下同じ）で少なくとも1.5以上、
好ましくは2.5以上が形状の均一なウイスカーを
得る目的に関して必要である。ここでこの上限は
特に設ける必要はないが、これをあまり大にして
たとえばＣ／Siが20以上と高い条件にすることは
炭素化合物の単なる損失にしかならない。Ｃ／Si
式量比の調節は、水蒸気を含む熱ガス中に装入す
るケイ素化合物と炭素化合物の流量を調節するこ
とにより容易に行なわれる。なお、ケイ素化合物
及び炭素化合物としてそのままで気相もしくは液
相状態か、昇温により容易に液相状態になり得る
化合物を選択すれば、この調節はさらに容易かつ
正確に行なうことが出来、従つて品質の安定した
含炭素組成物を容易に得ることが出来る。またこ
のような流動性の良い化合物であれば、特定不純
物の排除を必要とする場合は予め蒸留、吸着、洗
浄、過などの簡便な操作で達成できるので、高
純度の含炭素組成物を容易に得ることができる。
含炭素組成物を通気性構造体の共存下に加熱する
工程において、酸素が加熱雰囲気中に存在すると
単体炭素が燃焼除去されるためアルゴン、ヘリウ
ム、窒素などの非酸化性雰囲気中で加熱すること
が好ましい。しかしながら、通常の条件下では含
炭素組成物から炭化ケイ素が生成する過程で一酸
化炭素が副生し、おのずと非酸化性雰囲気となる
ため、本発明において脱酸素のため特に特別の手
段を施す必要はない。
本発明の実施の結果得られる炭化ケイ素ウイス
カーに残存した単体炭素あるいは薄肉の炭素質
は、該ウイスカーを酸素の存在下に500〜1000℃
に加熱してこれを燃焼することより容易に除去す
ることができる。該燃焼は空気中で加熱するか、
または燃料を過剰空気で燃焼させた酸素を含む熱
ガス雰囲気下におくことで簡便に行うことができ
ることは言うまでもない。
〔発明を実施するための好ましい形態〕
以下、実施例により、本発明の実施の態様をよ
り具体的に説明する。
なお、実験の結果得られたウイスカーの評価は
次のごとくして行つた。すなわち、電子顕微鏡映
像によつて、多数（400〜600本程度）のウイスカ
ーについてそれぞれ長さ(L)および幅(D)を求めＬ及
びＬ／Ｄ（アスペクト比）の算術平均値さらにＬ
の標準偏差をその形状を評価する因子とした。こ
れはウイスカーは金属、セラミツクスなどに加え
て補強剤として用いる場合、枝分れや湾曲がなく
直線状の形状であることが、金属等の中での分散
状態が均一になり易い点で望ましいとされている
こと、また長さ(L)が充分に長く、更に直径(D)に対
する長さの比（上記のごとくアスペクト比：Ｌ／
Ｄ）が大きい程、補強剤としての効果が大きいと
されていること、Ｌの標準偏差が小さい程補強効
果にバラツキが小さいことを考慮したものであ
る。
実施例 １
第３図に示す炉（直径300mm、長さ３ｍ）を用
い、ダクト２より空気を、燃焼バーナー３より熱
風用燃料としてのプロパンをそれぞれ70Nm3／
Ｈ，1.5Nm3／Ｈの流量で装入し、またケイ素化
合物としてSiCl4を、炭素化合物としてＡ重油を
予め重量比１：1.5に混合したものを15Kg／Ｈの
流量でノズル４より炉内に装入した。炉内は第３
図のＡの位置で920℃の温度に保つた。炉内に生
成したエーロゾルはダクト５より抜き出し、バツ
クフイルターで分散質を捕集して含炭素組成物
4.2Kg／Ｈ（乾燥重量）を得た。このものには炭素
50.0重量％、ケイ素23.4重量％（単体換算）が含
まれ（残りは結合性の酸素26.5重量％、その他
0.1重量％以下）、ESCAスペクトル解析の結果、
ケイ素と他元素の結合形態にはSi−Ｏ結合のみが
観察された。
この含炭素組成物600ｇとクラフト紙を素材と
した円筒（外径45mm、長さ60mm、内厚0.3mm第４
図ロ）を、窒素ガス雰囲気中800℃で10分間加熱
して得た炭素99.6％灰分0.4％の組成の炭化した
円筒状の小片380個（平均で外径32mm、長さ41mm、
肉厚0.2mm）とをＶ型混合機を用いて混合するこ
とにより本発明に規定する通気性構造体空隙部へ
の含炭素組成物の充填を行なつた後後、これを内
径180mm、高さ600mmの加熱空間を有する通電抵抗
加熱炉に詰めた。炉内に詰めた含炭素組成物の嵩
密度は、0.040ｇ／c.c.であり、構造単位たる同筒
小片と共存した状態で炉内に占める掛け容量は
15.0であつた。
次にアルゴン雰囲気中で1500℃、２時間の加熱
を行ない炭化ケイ素を生成させた。加熱前後の見
掛けの容積には全く変化はなく、構造単位たる円
筒小片も原形をとどめていた。
これを一旦冷却後空気中で700℃に加熱して残
存した単体炭素及び炭化したクラフト紙を燃焼除
去し、更にフツ酸水溶液で残存したケイ素酸化物
及びクラフト紙の灰分等を洗浄過して炭化ケイ
素164ｇを得た。粉末Ｘ線回析スペクトル解析の
結果結晶形状はβ型であり、電子顕微鏡映像観察
の結果針状のウイスカーのみが観察され、長さ
(L)、アスペクト比（Ｌ／Ｄ）の算術平均値はそれ
ぞれ27μｍ、63でＬの標準偏差は3.6μｍであつた。
第１図にその電子顕微鏡写真を示す。
比較例 １
実施例１で得た含炭素組成物600ｇとクラフト
紙を素材とした円筒そのもの（外径32mm、長さ40
mm、肉厚0.3mm）390個とをＶ型混合機を用いて混
合し、以下実施例１と全く同様にして加熱し炭化
ケイ素を生成させた。炉内に詰めた状態での含炭
素組成物の嵩密度は0.040ｇ／c.c.で見掛けの容積
は14.7であつたが、加熱後の状態では見掛けの
容積は11.3に低下しており、円筒形のクラフト
紙は炭化して１辺が約20％の収縮を生じていた
が、円筒形の形状にとどめていた。
これを実施例１と全く同様にして残存した単体
炭素及びケイ素酸化物を除去し炭化ケイ素153ｇ
を得た。粉末Ｘ線回析スペクトルの結果結晶形状
はβ型であり、電子顕微鏡映像観察の結果では炭
化ケイ素が生成した位置によつてその形状に相異
があることが観察され見掛けの容積が低下するこ
とによつて内部あるいは外周部に局部的に生じた
空隙部分には平均の長さの３倍程度の長さを持つ
真直ぐに成長したウイスカーが生成していること
が確認された。ただし炭化収縮した円筒の内壁面
にそつて部分的にではあるが第２図の電子顕微鏡
写真に示すように真直ぐなウイスカーのなかに短
く湾曲したウイスカーが副生していることが観察
され、Ｌ，Ｌ／Ｄの算術平均値はそれぞれ19μ
ｍ、58でＬの標準偏差は12.1μｍであつた。
実施例 ２
実施例１で用いた含炭素組成物600ｇと実施例
１で用いたのと同じ形状のクラフト紙を素材とし
これを炭化としこれを炭化して得た円筒状の小片
380個とをＶ型混合機を用いて混合する際に更に
塩化ナトリウム310ｇを加えて混合する以外は実
施例１と全く同様にして炭化ケイ素121ｇを得た。
加熱炉内に詰めた状態での含炭素組成物の嵩密
度は0.043ｇ／c.c.で見掛けの容積は13.9であり、
加熱後の見掛けの容積には全く変化がなかつた。
得られた炭化ケイ素は、粉末Ｘ線回析スペクトル
解析の結果結晶形状はβ型であり、電子顕微鏡映
像観察の結果、炭化ケイ素の生成した位置によら
ずＬ，Ｌ／Ｄが同程度で変動の小さい針状のウイ
スカーのみが観察され、それらの算術平均値はそ
れぞれ80μｍ、89でＬの標準差は5.1μｍであつた。
比較例 ２
未炭化の紙を用い金属ハロゲン化物を添加した
例として、含炭素組成物に、クラフト紙を素材と
した円筒そのもの（外径32mm、長さ40mm、肉厚
0.3mm）390個を混合する以外は実施例２と全く同
様にして、含炭素組成物600ｇと塩化ナトリウム
310ｇの混合物より炭化ケイ素925ｇを得た。
加熱炉内に詰めた状態での含炭素組成物の嵩比
重は0.048ｇ／c.c.で見掛けの容積は12.6であつ
たが、加熱後の状態では見掛けの容積は9.7に
低下しており、円筒形のクラフト紙は炭化して１
辺が約20％の収縮を生じていた。
得られた炭化ケイ素は、粉末Ｘ線回析スペクト
ル解析の結果結晶形状はβ型であり、電子顕微鏡
映像観察の結果炭化ケイ素が生成した位置によつ
てその形状に相異があることが観察され、見掛け
の容積が低下することによつて内部あるいは外部
に局部的に生じた空隙部分には、平均の長さの５
倍程度の長さを持つ真直ぐに成長したウイスカー
が生成していることが確認された。ただし炭化し
て収縮した円筒の内壁面にそつて部分的にではあ
るが第２図の電子顕微鏡写真のような短く湾曲の
多いウイスカーが副生していることが観察され、
Ｌ，Ｌ／Ｄの算術平均値はそれぞれ73μｍ、81で
Ｌの標準偏差値は20.1であつた。
比較例 ３
実施例１で含炭素組成物を得たと全く同様にし
て生成させたエーロゾルを第３図のダクト５より
抜き出し、湿式サイクロンを用いて、水100重量
部に対し含炭素組成物が11重量部分散されたスラ
リー状態で捕集した。これを過、乾燥して得た
含炭素組成物には炭素50.5重量％、ケイ素23.1重
量％が含まれ（残りは結合性の酸素26.3重量％、
その他0.1重量％以下）、嵩密度は0.55ｇ／c.c.でケ
ーク状であつた。これをふるい振とう器で解砕し
ながら60メツシユの金網に通過させて得た嵩比重
が0.27ｇ／c.c.の4120ｇと実施例１で用いたと全く
同じ炭素質の同筒状小片380個とをＶ型混合機を
用いて混合した後、実施例１と全く同様にして加
熱し、炭化ケイ素148ｇを得た。加熱炉内に詰め
た状態での内容物の掛けの容積は15.2で加熱後
の見掛けの容積は15.0であつた。
得られた炭化ケイ素は、粉末Ｘ線回析スペクト
ル解析の結果、結晶形状はβ型であり、電子顕微
鏡映像観察の結果、大部分は微粒子状結晶であつ
て、ウイスカーは極く少量のみが観察された。
以上実施例１，２から明らかなごとく本発明に
従えば長さが均等でアスペクト比が大きい形状の
勝れたウイスカーが得られ、金属ハロゲン化物を
添加しておけば、より長いウイスカーが得られる
ことが理解される。比較例１，２からウイスカー
焼成中に収縮を生ずる通気性構造体を使用する条
件下では、金属ハロゲン化物の添加の有無にかか
わらず部分的ではあるが長さの分布が広がり易い
こと、比較例３から特に嵩比重の高い条件を選択
した場合は通気性構造体の共存下においても主に
微粒子状結晶が生成し易いことが理解される。
実施例 ３〜９
実施例１における熱風用燃料には、プロパンの
他に水素、メタンも用い、分解性のケイ素化合
物、炭素化合物としては第１表に示すものを、同
表に示す重量比で混合してノズル４より炉内に装
入し、それぞれバツクフイルターで捕集して、そ
れぞれ同表に示す捕集量組成の、記号イ〜ニで示
した含炭素組成物を得た。含炭素組成物中のケイ
素と他元素の結合形態をESCAスペクトルで解析
した結果、いずれもSi−Ｏ結合のみが観察され
た。これらそれぞれ第２表に示す記号及び重量の
含炭素組成物に、通気性構造体を構成するための
下記のごとき小片と、（さらに実施例４，６，７，
８，９においてはそれぞれ第２表に示すハロゲン
化物を加えて）Ｖ型混合機を用いて混合した後、
実施例１で用いた通電抵抗炉に充填し、アルゴン
雰囲気中でそれぞれ第２表に示す温度、時間の加
熱を行ない炭化ケイ素を生成させた。ここで通気
性構造体を構成する構造単位たる小片は、実施例
３〜５においてはクラフト紙を素材とし、それを
元の形状を保持したまま炭化して得た実施例１で
用いたと同じ形状の円筒380個をそれぞれ用い、
実施例６〜８においてロール紙を素材としたヒモ
状の小片（肉厚0.4mm、巾７mm、長さ10cm、第４
図７）を窒素ガス雰囲気中600℃で20分間加熱し
て得た炭素99.7重量％灰分0.3重量％の組成の炭
化したヒモ状の小片（肉厚0.2mm、巾４mm、長さ
6.8cm）1900個をそれぞれ用い実施例９において
は板紙を素材とした円錐状の小片（肉厚0.7mm、
底面積1.6cm2、高さ40mm、第４図ホ）を窒素ガス
雰囲気中1000℃で加熱して得た炭素99.7重量％、
灰分0.3重量％の組成の炭化した円錐状の小片
（肉厚0.4mm、底面積0.98cm2、高さ29mm）6200個を
それぞれ用いた。加熱炉内に詰めた状態での含炭
素組成物の嵩密度及び見掛けの容積はそれぞれ第
２表に示した通りであつた。これらを加熱した後
の状態としては、見掛けの容積にはほとんど変化
がなく、また小片の形状や寸法にもほとんど変化
がなかつた。
これらより実施例１と同様にして、残存した炭
素、ケイ素酸化物等を除去して第２表に示す量の
炭化ケイ素を得た。粉末Ｘ線回析スペクトル解析
の結果、結晶形状はいずれもβ型であり、電子顕
微鏡映像観察の結果、長さ(L)、アスペクト比
（Ｌ／Ｄ）の変動が小さく、微粒子状結晶を殆ん
ど含まない針状のウイスカーであることが観察さ
れ、Ｌ，Ｌ／Ｄの算術平均値及びＬの標準偏差は
それぞれ第２表に示した通りであつた。
[Technical Field] The present invention relates to a novel method for producing silicon carbide whiskers. [Prior art] The conventional technology for producing silicon carbide whiskers is to combine vapors of silicon compounds such as SiCl 4 and carbon compounds such as toluene (C 7 H 8 ) and CCl 4 in a reactor in a high-temperature atmosphere using a hydrogen stream. A method is known in which the crystal growth is obtained by transporting it to a gas phase, reacting it in the gas phase, and then precipitating it in a low-temperature part on the downstream side of the reactor (for example, "Crystal Growth", edited by the Japan Institute of Metals, (March 30, 1982), Maruzen). , p354). However, with this method, there are problems in that a considerable amount of the silicon compound evaporates out of the reaction system in a gaseous state and that a large amount of hydrogen is required to be supplied.Furthermore, the whisker precipitation equipment has changed from a small batch method to an industrial one. The drawback was that it was difficult to make it larger. In addition, methods for producing silicon carbide whiskers from solid raw materials include heating rice grains in a carbon monoxide atmosphere (Japanese Patent Application Laid-Open No. 113300/1982), and carbonized rice grains obtained by heating rice grains once. A method of heating again in a non-oxidizing atmosphere
20799), and a method in which carbon black is mixed with the ash obtained by burning rice grains and then heated in a non-oxidizing atmosphere (Japanese Patent Application Laid-Open No. 1983-45195). However, the properties of rice grain, which is an agricultural by-product, vary depending on the weather, place of production, and variety, and various impurities and foreign substances are likely to be mixed in during the collection and transportation process, so the quality of the silicon carbide whiskers obtained is The disadvantage is that it is difficult to stabilize. In the method of heating rice grains, fine particulate silicon carbide crystals are heated at a weight ratio of approximately twice that of the obtained silicon carbide whiskers to heat the carbide of the rice grains or the mixture of the ash of the rice grains and carbon black. In this case, fine particulate silicon carbide crystals are produced at the same time at the same polymerization rate, and whiskers are obtained in a mixed state of whiskers and fine particulate crystals, so it is not possible to obtain whiskers in a high yield. It is not easy to separate and extract just the whiskers from the whiskers, and even after the separation operation, a considerable amount of fine particulate crystals remain in the whiskers.
When this is added to metals, ceramics, etc. for the purpose of reinforcing them, there is a drawback in that it is difficult to obtain fully satisfactory results. As a result of examining the advantages and disadvantages of these conventional techniques, the inventors of the present invention previously proposed a method for oxidizing silicon by charging and decomposing decomposable silicon compounds and carbon compounds in hot gas containing water vapor, as disclosed in Japanese Patent Application Laid-Open No. 59-121198. A carbon-containing composition having a bulk specific gravity of 0.2 g/cc or less is obtained by generating a mixed aerosol dispersoid containing aerosols of carbon and elemental carbon, and collecting the generated dispersoid by a solid-gas separation operation. We proposed a method for producing silicon carbide whiskers by heating. This method can continuously obtain a carbon-containing composition of extremely high purity and uniform quality without any mechanical grinding or mixing operations, and by heating the carbon-containing composition, fine particulate crystals can be obtained. This is an extremely innovative method in principle, as it can produce only silicon carbide whiskers with almost no by-products. However, as mentioned above, although this method is excellent in principle and in essence, when trying to apply it to an industrial scale device,
For example, when trying to increase the size of heating equipment such as an electric furnace for heating a carbon-containing composition from a laboratory scale to an industrial scale, simply increasing the space volume occupied by the object to be heated, In addition to the method of increasing the filling amount of whiskers, which grow straight, have uniform length and thickness, and have excellent uniformity of shape,
It has been found that there is a problem in that whiskers from defective products, which are short, often curved, and irregular, are also included as by-products. That is, when a carbon-containing composition is heated in an electric furnace or the like,
As the reaction progresses, the apparent volume occupied by the reaction product rapidly decreases to less than half of the apparent volume at the time of preparation, and a long outer portion with a thickness of about 10 mm faces the void created by the contraction. It is estimated that good whiskers that grow straight are produced, but defective whiskers that are relatively short and curved are produced inside the whiskers. As a result of intensive studies based on this reasoning, the inventors of the present invention have developed the previously proposed Japanese Patent Application Laid-Open No.
As a method for improving the method of Publication No. 121198 (hereinafter referred to as the basic method), when heating a carbon-containing composition, a breathable structure having continuous voids is formed in the heated part, and the carbon-containing composition is heated. A new method was proposed in which the heating is performed while the voids of the structure are filled with (Japanese Patent Application No. 59-137091, hereinafter referred to as the "improved method"). If the breathable structure has small pieces in the shape of columns or cylinders as structural units, the carbon-containing composition and the pieces are simply mixed mechanically, and then this mixture is placed in a heating furnace. By introducing the carbon-containing composition into the air-permeable structure, the carbon-containing composition can be heated in a state in which the voids of the breathable structure are filled. In addition, the material of the small piece is a material whose main component is cellulose,
If it is made into so-called paper, it is industrially very advantageous because it is easy to process, inexpensive, and can be removed by combustion. If a carbon-containing composition is heated in the presence of an air-permeable structure according to the improved method as described above, the problem of the short and often curved defective whiskers in the basic method being mixed in as a by-product can be significantly reduced. Most of the whiskers produced were long and straight. However, the distribution of their lengths is not completely satisfactory; depending on the conditions, lengths up to 5 times the average length or less than one-third of the average length may be produced, and lengths that are shorter than the average length may be produced. A small amount of whiskers from defective products with a lot of curvature may also be produced as a by-product. The present inventors speculated as to the cause of these problems as follows. In other words, when paper is used as the material for the breathable structure, when the paper is heated and undergoes thermal decomposition and carbonization, one side is 10 times smaller than the original size.
~35% shrinkage. Due to this contraction, voids are generated inside or on the outer periphery of the mixture of the carbon-containing composition and the pieces constituting the breathable structure. This is presumably because a portion of the carbon composition is consolidated, and thus non-uniformity in air permeability may occur depending on the position of the carbon-containing composition. [Object of the Invention] An object of the present invention is to further improve the basic method and its improvement method, and to provide a method that can achieve its original effects even more effectively and with good reproducibility. Another object of the invention is to provide a process which is particularly suitable for implementing such a basic process on an industrial scale. Still another object of the present invention is to provide a method for producing whiskers of uniform length and thickness and excellent uniformity of shape even when the basic method is carried out particularly on an industrial scale. Further objects of the invention will become apparent from the description below. [Disclosure of the Invention] As a result of intensive studies in view of the above points, the present inventors formed a breathable structure in a method for producing silicon carbide whiskers in which a carbon-containing composition is made to coexist with a breathable structure and heated. If the material is a thin carbonaceous material, the dimensions of the breathable structure will not change when heated, and the shape of the resulting whiskers will be much more uniform regardless of the heating position, and the length will be much smaller. The inventors have discovered a phenomenon in which the distribution becomes extremely narrow, and short, curved particles are hardly produced, leading to the present invention. That is, according to the present invention, a decomposable silicon compound and a carbon compound are charged and decomposed in a hot gas containing water vapor to produce a mixed aerosol fraction containing aerosols of silicon oxide and elemental carbon, respectively, When heating a carbon-containing composition having a bulk density of 0.2 g/cc or less obtained by collecting the generated dispersoids by a solid-gas separation operation to 1300 to 1800°C, a continuous A method for producing silicon carbide whiskers, in which a breathable structure having voids is formed, and the heating is performed with the carbon-containing composition filled in the voids of the structure, wherein the material forming the breathable structure Provided is a method for producing silicon carbide whiskers, characterized in that the whiskers are a thin-walled carbonaceous material, preferably a carbide of a thin-walled material whose main component is cellulose. [Detailed Disclosure of the Invention] The present invention will be described in detail below. Regarding the carbon-containing composition used in the present invention, first, an aerosol of simple carbon can be easily obtained by introducing a decomposable carbon compound into hot gas. On the other hand, silicon oxide aerosols can be obtained by hydrolysis or oxidation when a decomposable silicon compound, such as SiCl4 , is introduced into a hot gas containing water vapor. As can be easily understood, if a decomposable carbon compound and a decomposable silicon compound are simultaneously charged into a hot gas containing water vapor, a mixed aerosol containing elemental carbon and silicon oxide is immediately formed. Decomposable silicon compounds that can be used in the present invention are those represented by the general formula Si o Yes, some specific silicon compounds are:
SiCl 4 , HSiCl 3 , SiH 4 , Si 2 H 6 , (CH 3 ) 4 Si,
( CH3 ) 2SiCl2 , CH3SiCl3 , SiF4 , Si( OC2H5 ) 4 , etc. These may be used alone or in mixtures. The decomposable carbon compound used in the implementation of the present invention is
When charged in a hot gas as described later, it can easily decompose to produce elemental carbon, and it is either in the gas or liquid phase as it is, or easily becomes the liquid phase by increasing the temperature. What is obtained can be suitably used. For example, LPG, naphtha, gasoline,
Petroleum products such as fuel oil, kerosene, light oil, heavy oil, lubricating oil, and liquid paraffin; methane, ethane, propane, butane, pentane, methanol, ethanol, propanol, ethylene, acetylene, n-
Paraffin, butadiene, isoprene, isobutylene, benzene, toluene, xylene, cyclohexane, cyclohexene, dicyclopentadiene, ethylbenzene, styrene, kyumene, pseudocumene, mesitylene, alkylbenzene, α
-Methylstyrene, dicyclododecatriene, diisobutylene, vinyl chloride, chlorobenzene,
Petrochemical products such as C9 distillate mixtures and ethylene bottoms; tar products such as tar, pitch, creosote oil, naphthalene, anthracene, carbazole, tar acid, phenol, cresol, xylenol, pyridine, picoline, and quinoline; large Oils and fats include bean oil, coconut oil, linseed oil, cottonseed oil, rapeseed oil, tung oil, castor oil, whale oil, beef tallow, squalane, oleic acid, and stearic acid. In the present invention, the purpose of the decomposable carbon compound is to supply carbon, so the type thereof can be selected from a wide range. However, from the viewpoint of ease of handling and carbon yield, toluene, xylene, benzene, kerosene, light oil, heavy oil, C9 distillate mixture, ethylene bottom, etc. are preferred. It is preferable to use a furnace to decompose these in a hot gas containing steam to obtain the fine carbon-containing composition used in the present invention. This furnace is equipped with a heating device, a nozzle for charging silicon compounds and carbon compounds, a gas charging duct, and a mixed aerosol discharge duct, and the heating device includes a combustion burner,
There are electric heating elements, but combustion burners are preferable because they are simple and thermally efficient. FIG. 3 shows an example of a furnace used for this purpose. There must be a void area within this furnace that is at least 600°C or higher. At temperatures above this temperature, elemental carbon is obtained from carbon compounds, and silicon oxide is obtained from silicon compounds in an atmosphere containing water vapor, generating a mixed aerosol state that is a mixture of gas and these solids. Hot gas containing water vapor can also be obtained by injecting water vapor into hot gas obtained by an electric heating method, high frequency heating method, or electric discharge method, but hydrogen, methane, ethane, etc. The method of using air to combust combustible materials such as propane or hydrocarbons used as raw materials, which produce water vapor when combusted, is simple and economical in terms of thermal efficiency. The silicon compound used in the practice of the present invention has the property of being converted into a solid silicon oxide by a hydrolysis reaction in a hot gas containing water vapor, and also converted into a solid silicon oxide by an oxidation or thermal decomposition reaction. These reactions are extremely fast and complete in about 0.1 to 0.5 seconds, so if the residence time in the reaction zone is about 1 to 10 seconds, in an atmosphere where heat and water vapor coexist, silicon The compound rarely evaporates out of the reaction system while remaining in an unreacted gas state. The mixed aerosol obtained as above is
After the aerosol is guided out of the furnace, the solid dispersoids contained in the aerosol are collected by solid-gas separation using a collection device such as a bag filter, cyclone, or electrostatic precipitator. The carbon-containing composition collected in this way has a temperature of 1300 to
Silicon carbide whiskers can be obtained by heating to 1800°C, preferably 1400 to 1600°C. In the present invention, when heating the carbon-containing composition obtained as described above to form silicon carbide whiskers, an air-permeable structure having continuous voids is formed in the heating section, and the carbon-containing composition is heated to form silicon carbide whiskers. The method is characterized in that the heating is performed while the composition is filled in the voids of the structure. The breathable structure referred to in the present invention is a three-dimensional structure formed by stacking a large number of three-dimensional small pieces as shown below as a structural unit to form continuous voids that allow ventilation. This refers to a thin carbonaceous material that has a similar structure and whose continuous voids are maintained even when heated at 1300 to 1800°C. The shape of the three-dimensional piece that is the structural unit is as follows:
Preferred shapes include cylinders, cylinders, cones, spheres, triangular prisms, triangular pyramids, cubes, square prisms, square pyramids, tetrapot shapes, and string shapes, and their sizes are cylindrical,
In the case of cones, triangular prisms, etc., the base area is 0.1 to 20 cm2 , preferably 0.5 to 5 cm2 , and the height is preferably 0.2 to 10 cm.
0.5-5cm is suitable, and if it is string-like, the width is 0.1
-5 cm, preferably 0.2-2 cm, and the length is preferably 0.5-20 cm, preferably 1-10 cm. Although FIG. 4 shows an example of the shape of the small pieces that are the structural units for forming the above-mentioned breathable structure, it is not limited to regular shapes such as those shown in A to F. It may be in the shape of a horse's saddle as shown in Figure 1, or in the shape of a terraret as shown in Figure 1, or in the shape of a long string or a short string. As can be easily understood, a breathable structure having continuous voids can be easily formed by stacking one or more of these types in large numbers regularly or irregularly. . In order to fill the voids of the structure formed in this manner with a carbon-containing composition, first, small structural unit pieces are filled regularly or irregularly, and then the carbon-containing composition is added to the voids. The filling layer may be formed after the structural unit pieces and the composition are thoroughly mixed. When the latter method is adopted, the carbon-containing composition is mixed with a large number of small pieces in the coexistence of an air-permeable structure made up of a large number of small pieces, and the mixture is heated in a heating furnace. The state where the carbon-containing composition coexists in the voids created by stacking many small pieces is heated at 1300 to 1800℃.
Silicon carbide whiskers with a uniform shape can be obtained by heating to . Here, if the shape of the small piece is, for example, cylindrical, and the inside of the small piece is also a continuous void, the volume that can be filled with the carbon-containing composition in the heating furnace will not be significantly reduced. The device for mixing the carbon-containing composition and the small pieces, which are the structural units constituting the breathable structure, is also a device in which the carbon-containing composition is less likely to be compacted during the mixing process, such as a double circle shape, a V shape, a ribbon shape, etc. Mixers such as , or air flow floating mixers are suitable. Here, if the weight of the small pieces is large, the carbon-containing composition is likely to be compacted during this mixing process, and therefore it is preferable that the small pieces are thin and light in weight. Carbonaceous substances are suitable as the material for the pieces.
The reason for this is that the carbonaceous material hardly changes in size or shape even when heated to 1300 to 1800°C, and the voids can be maintained as they were before heating. Graphite, charcoal, carbonized resin moldings, or carbonized wood with a thickness of several millimeters or less can be suitably used as the carbonaceous material, but more preferably materials whose main component is cellulose, Preferably, the structural unit pieces are formed from paper such as so-called Western paper or paperboard, and then carbonized while maintaining their shape. This is because the paper itself is a thin material, and compared to other materials, it is easier to process into various shapes and is also cheaper. When these papers (small structural unit pieces formed by them) are heated in an inert gas atmosphere at 300°C or higher, preferably 450°C or higher for 5 minutes or more, they become thin-walled charcoal while retaining almost their original shape. In this case, the dimensions shrink by 10 to 35% compared to before heating, but the shape remains almost the same, and once carbonized by such heating, the temperature at which silicon carbide whiskers are obtained is Even when heated again to 1,300 to 1,800 degrees Celsius, there is almost no change in size or shape. The bulk density of the carbon-containing composition coexisting with the breathable structure is required to be 0.2 g/cc or less, preferably 0.15 g/cc or less before heating. This is based on the inventors' experimental findings that when the bulk density exceeds 0.2 g/cc, the tendency of silicon carbide obtained by heating to become granular or curved sharply increases. As described above, silicon carbide whiskers with a uniform shape can be obtained by heating a carbon composition with a bulk density of 0.2 g/cc or less in the presence of an air-permeable structure. , NaF,
NaCl, NaBr, KF, KCl, KBr, MgF2 ,
Longer whiskers can be obtained by adding an alkali metal or alkaline earth metal halide such as MgCl 2 , CaF 2 , CaCl 2 to a carbon-containing composition and heating it. The addition ratio of these halides such as alkali metals is preferably 0.3 to 3 mol, more preferably 0.5 to 2 mol, per 1 mol of silicon oxide in the carbon-containing composition, compared to the case where they are not added. The effect of increasing the length by 2 to 5 times is observed. As a method of addition, it may be mixed with the carbon-containing composition using a mixer such as the above-mentioned double circular swivel type, or it may be placed at the bottom of a heating furnace. The ratio of carbon to silicon oxide in the carbon-containing composition is at least 1.5 in terms of C/Si (formula ratio: g-atom C/g-atom Si; the same applies hereinafter);
Preferably 2.5 or more is required for the purpose of obtaining whiskers with uniform shape. Although there is no need to set this upper limit, setting it too high to a high C/Si ratio of 20 or more, for example, will only result in a loss of carbon compounds. C/Si
The formula weight ratio can be easily adjusted by adjusting the flow rates of the silicon compound and carbon compound charged into the hot gas containing water vapor. Note that this adjustment can be performed more easily and accurately by selecting silicon compounds and carbon compounds that are in a gas or liquid phase as they are, or compounds that can easily become a liquid phase by increasing the temperature. A carbon-containing composition with stable quality can be easily obtained. In addition, with such a highly fluid compound, if it is necessary to eliminate specific impurities, it can be achieved by simple operations such as distillation, adsorption, washing, and filtration, making it easy to prepare high-purity carbon-containing compositions. can be obtained.
In the process of heating a carbon-containing composition in the presence of a breathable structure, if oxygen is present in the heating atmosphere, elemental carbon will be burned and removed, so heating should be done in a non-oxidizing atmosphere such as argon, helium, nitrogen, etc. is preferred. However, under normal conditions, carbon monoxide is produced as a by-product in the process of producing silicon carbide from a carbon-containing composition, naturally resulting in a non-oxidizing atmosphere. Therefore, in the present invention, it is necessary to take special measures to remove oxygen. There isn't. The elemental carbon or thin carbonaceous material remaining in the silicon carbide whiskers obtained as a result of carrying out the present invention can be removed by heating the whiskers at 500 to 1000°C in the presence of oxygen.
It can be easily removed by heating and burning it. The combustion is heated in air or
Alternatively, it goes without saying that this can be easily carried out by burning the fuel with excess air and placing it in a hot gas atmosphere containing oxygen. [Preferred Modes for Carrying Out the Invention] Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples. Note that the whiskers obtained as a result of the experiment were evaluated as follows. That is, the length (L) and width (D) of a large number of whiskers (approximately 400 to 600 whiskers) are determined using electron microscope images, and the arithmetic mean value of L and L/D (aspect ratio) is determined.
The standard deviation of the shape was used as a factor to evaluate the shape. This is because when whiskers are used as a reinforcing agent in addition to metals, ceramics, etc., it is desirable that the whiskers have a straight shape without branching or curving, as this will facilitate uniform dispersion in the metal. The length (L) is sufficiently long, and the ratio of the length to the diameter (D) (aspect ratio: L/
This takes into consideration the fact that it is said that the larger D) is, the greater the effect as a reinforcing agent is, and the smaller the standard deviation of L is, the smaller the variation in the reinforcing effect is. Example 1 Using the furnace shown in Fig. 3 (diameter 300 mm, length 3 m), air was supplied from duct 2 and propane as hot air fuel was supplied from combustion burner 3 at 70 Nm 3 /
A mixture of SiCl 4 as a silicon compound and heavy oil A as a carbon compound at a weight ratio of 1:1.5 was charged into the furnace through nozzle 4 at a flow rate of 15 kg/H. It was loaded into Inside the furnace is the third
The temperature was maintained at 920°C at position A in the figure. The aerosol generated in the furnace is extracted from the duct 5, and the dispersoid is collected by a back filter to form a carbon-containing composition.
4.2Kg/H (dry weight) was obtained. This thing has carbon
Contains 50.0% by weight, 23.4% by weight of silicon (in terms of single element) (the rest is 26.5% by weight of binding oxygen, and other
0.1% by weight or less), the results of ESCA spectrum analysis,
Only Si-O bonds were observed in the bonding form between silicon and other elements. A cylinder made of 600 g of this carbon-containing composition and kraft paper (outer diameter 45 mm, length 60 mm, inner thickness 0.3 mm)
380 carbonized cylindrical pieces (average outer diameter 32 mm, length 41 mm,
After filling the voids of the breathable structure specified in the present invention with the carbon-containing composition by mixing the carbon-containing composition with a V-type mixer, the carbon-containing composition was mixed with It was packed in a current-carrying resistance heating furnace with a heating space of 600 mm in length. The bulk density of the carbon-containing composition packed in the furnace is 0.040 g/cc, and the loading capacity occupied in the furnace when it coexists with the cylindrical pieces that are the structural unit is
It was 15.0. Next, heating was performed at 1500° C. for 2 hours in an argon atmosphere to generate silicon carbide. There was no change in the apparent volume before and after heating, and the small cylindrical piece, which was the structural unit, remained in its original shape. After cooling it, it is heated to 700℃ in air to burn off the remaining elemental carbon and carbonized kraft paper, and then the remaining silicon oxide and ash of the kraft paper are washed with a hydrofluoric acid aqueous solution and carbonized. 164 g of silicon was obtained. As a result of powder X-ray diffraction spectrum analysis, the crystal shape is β type, and as a result of electron microscope image observation, only needle-shaped whiskers were observed, and the length was
The arithmetic mean values of (L) and aspect ratio (L/D) were 27 μm and 63, respectively, and the standard deviation of L was 3.6 μm. Figure 1 shows an electron micrograph. Comparative Example 1 600g of the carbon-containing composition obtained in Example 1 and a cylinder itself made of kraft paper (outer diameter 32mm, length 40mm)
mm, wall thickness 0.3 mm) using a V-type mixer, and heated in exactly the same manner as in Example 1 to produce silicon carbide. The bulk density of the carbon-containing composition packed in the furnace was 0.040 g/cc and the apparent volume was 14.7, but after heating, the apparent volume decreased to 11.3, and the cylindrical shape The kraft paper had carbonized and shrunk by about 20% on one side, but it remained in a cylindrical shape. The remaining elemental carbon and silicon oxide were removed in the same manner as in Example 1, and 153 g of silicon carbide was obtained.
I got it. The powder X-ray diffraction spectrum shows that the crystal shape is β-type, and the electron microscope image observation shows that the shape differs depending on the position where silicon carbide is formed, and the apparent volume decreases. It was confirmed that straight-grown whiskers having a length of about three times the average length were formed in the voids locally formed inside or on the outer periphery. However, as shown in the electron micrograph in Figure 2, short curved whiskers were observed to be by-produced among the straight whiskers, albeit partially along the inner wall surface of the cylinder that had undergone carbonization and shrinkage. , the arithmetic mean value of L/D is 19μ, respectively.
m, the standard deviation of L was 12.1 μm at 58. Example 2 A small cylindrical piece obtained by carbonizing 600 g of the carbon-containing composition used in Example 1 and kraft paper of the same shape as that used in Example 1.
121 g of silicon carbide was obtained in exactly the same manner as in Example 1 except that 310 g of sodium chloride was further added and mixed when 380 pieces were mixed using a V-type mixer. The bulk density of the carbon-containing composition packed in the heating furnace was 0.043 g/cc, and the apparent volume was 13.9.
There was no change in the apparent volume after heating.
As a result of powder X-ray diffraction spectrum analysis, the crystal shape of the obtained silicon carbide was β type, and as a result of electron microscope image observation, L and L/D fluctuated at the same level regardless of the position where silicon carbide was formed. Only small needle-like whiskers were observed, and their arithmetic mean values were 80 μm and 89, respectively, and the standard difference in L was 5.1 μm. Comparative Example 2 As an example of adding a metal halide using uncarbonized paper, a cylinder itself made of kraft paper (outer diameter 32 mm, length 40 mm, wall thickness
600 g of carbon-containing composition and sodium chloride were prepared in exactly the same manner as in Example 2 except that 390 pieces (0.3 mm) were mixed.
925 g of silicon carbide was obtained from 310 g of the mixture. The bulk specific gravity of the carbon-containing composition when packed in the heating furnace was 0.048 g/cc and the apparent volume was 12.6, but after heating, the apparent volume decreased to 9.7, and it became cylindrical. The kraft paper is carbonized and
The edges had shrunk by about 20%. As a result of powder X-ray diffraction spectrum analysis, the obtained silicon carbide had a β-type crystal shape, and as a result of electron microscope image observation, it was observed that the shape differed depending on the position where silicon carbide was formed. , the voids locally created internally or externally due to a decrease in the apparent volume have an average length of 5
It was confirmed that whiskers that grew straight and were about twice as long were generated. However, it was observed that short, curved whiskers, as shown in the electron micrograph in Figure 2, were partially produced along the inner wall surface of the cylinder that had contracted due to carbonization.
The arithmetic mean values of L and L/D were 73 μm and 81, respectively, and the standard deviation value of L was 20.1. Comparative Example 3 An aerosol produced in exactly the same manner as in Example 1 to obtain the carbon-containing composition was taken out from the duct 5 in FIG. It was collected in the form of a slurry that was partially dispersed by weight. The carbon-containing composition obtained by filtering and drying this contains 50.5% by weight of carbon and 23.1% by weight of silicon (the remainder being 26.3% by weight of binding oxygen,
Others (0.1% by weight or less), the bulk density was 0.55 g/cc, and it was cake-like. This was crushed with a sieve shaker and passed through a 60-mesh wire gauze to obtain 4120 g with a bulk specific gravity of 0.27 g/cc, and 380 small cylindrical pieces of the same carbonaceous material as used in Example 1. After mixing using a V-type mixer, the mixture was heated in exactly the same manner as in Example 1 to obtain 148 g of silicon carbide. The multiplication volume of the contents packed in the heating furnace was 15.2, and the apparent volume after heating was 15.0. As a result of powder X-ray diffraction spectrum analysis, the crystal shape of the obtained silicon carbide was found to be β-type, and as a result of electron microscopy image observation, it was found that most of the silicon carbide was in the form of fine particles, with only a small amount of whiskers observed. It was done. As is clear from Examples 1 and 2 above, according to the present invention, excellent whiskers with uniform length and a large aspect ratio can be obtained, and by adding a metal halide, longer whiskers can be obtained. That is understood. Comparative Examples 1 and 2 show that under the conditions of using a breathable structure that causes shrinkage during whisker firing, the length distribution tends to widen, albeit partially, regardless of the presence or absence of metal halide addition; Comparative Examples It is understood from 3 that when conditions with particularly high bulk density are selected, mainly fine particulate crystals are likely to be produced even in the presence of an air-permeable structure. Examples 3 to 9 In addition to propane, hydrogen and methane were also used as the hot air fuel in Example 1, and the decomposable silicon compounds and carbon compounds shown in Table 1 were used in the weight ratios shown in the table. They were mixed and charged into a furnace through nozzle 4, and each was collected by a back filter to obtain carbon-containing compositions shown by symbols A to D, each having a collection amount composition shown in the same table. As a result of analyzing the bond form between silicon and other elements in the carbon-containing composition using ESCA spectroscopy, only Si-O bonds were observed in all cases. In addition to the carbon-containing compositions having the symbols and weights shown in Table 2, the following small pieces for constructing the breathable structure (in addition, Examples 4, 6, 7,
8 and 9, after adding the halides shown in Table 2) and mixing using a V-type mixer,
The materials were filled in the current-carrying resistance furnace used in Example 1, and heated in an argon atmosphere at the temperatures and times shown in Table 2 to produce silicon carbide. Here, in Examples 3 to 5, the small pieces that are the structural units constituting the breathable structure were made of kraft paper and had the same shape as that used in Example 1, which was obtained by carbonizing it while maintaining its original shape. Using 380 cylinders each,
In Examples 6 to 8, a small piece of string made of roll paper (thickness 0.4 mm, width 7 mm, length 10 cm, fourth
Fig. 7) was heated at 600℃ for 20 minutes in a nitrogen gas atmosphere to obtain carbonized string-like pieces with a composition of 99.7% carbon and 0.3% ash (thickness 0.2mm, width 4mm, length
In Example 9, 1,900 small conical pieces (thickness 0.7 mm,
99.7% carbon by weight, obtained by heating 1.6 cm 2 in base area, 40 mm in height, (Fig. 4 E) at 1000°C in a nitrogen gas atmosphere,
6200 carbonized conical pieces (wall thickness 0.4 mm, base area 0.98 cm 2 , height 29 mm) each having a composition of 0.3% by weight of ash were used. The bulk density and apparent volume of the carbon-containing composition packed in the heating furnace were as shown in Table 2, respectively. After heating these, there was almost no change in the apparent volume, and there was also almost no change in the shape or size of the pieces. From these, residual carbon, silicon oxide, etc. were removed in the same manner as in Example 1 to obtain silicon carbide in the amounts shown in Table 2. As a result of powder X-ray diffraction spectrum analysis, the crystal shape is β type, and as a result of electron microscope image observation, fluctuations in length (L) and aspect ratio (L/D) are small, and most of the crystals are in the form of fine particles. The arithmetic mean values of L and L/D and the standard deviation of L were as shown in Table 2, respectively.
【表】【table】
【表】【table】
以上のごとく本発明に従えば従来問題とされて
いた短く湾曲の多いウイスカーや微粒子状結晶を
ほとんど副生することなく、真直ぐに成長した長
さ・太さが均等な勝れた形状のウイスカーを工業
的規模の装置においてもきわめて容易かつ再現性
よく得ることができる。その理由の詳細について
もちろん必ずしも明らかではないものの、本発明
者らは一応次のように推測している。
(1) 炭化ケイ素ウイスカーが生成するにおいての
反応は次の〜式である。即ち式
SiO2＋Ｃ→SiO＋CO …
SiO＋3CO→SiC＋2CO2 …
CO2＋Ｃ→2CO …
によつてガス状態のSiOとCOが発生し、これ
らより式の反応が起きることによつてウイス
カーが成長し、副生したCO2は式によりCO
に戻る。言うまでもなくSiCウイスカーが成長
するということは、成長点で新たにSiCが生成
することであり、従つて成長点に供給されるSi
及びＣ源は、SiOやCOのようにガス状態であ
るとが必要である。
(2) 含炭素組成物は熱ガス中に同時に装入したケ
イ素化合物及び炭素化合物が一旦気化し、気相
で分子レベルの混合状態になつた後、化学反応
によつてケイ素酸化物と単体炭素に変化したも
のであり、従つてこれらケイ素酸化物と単体炭
素の混合状態が従来になくミクロの状態である
ために、式の反応が容易に進行し、SiCウイ
スカー源となるSiO及びCOが系内に充分多く
発生する。
(3) ウイスカーが生成する過程で、SiOやCOが
一部揮散するために、また生成したウイスカー
の絡み合いによつて、加熱炉内で含炭素組成物
が占めていた見掛けの容積は減少し、空隙が生
じる。
(4) 該空隙部に面した部分とその内側とではSiO
やCOと接触する確率が異なることが推測され、
そうであるとすれば前者はこの確率が高いため
長く、真直ぐに成長したものとなるが、後者は
この確率が低いため短く、湾曲の多いものとな
るであろう。
(5) しかして含炭素組成物を本発明の薄肉状の炭
素質を素材とした通気性構造体とくにセルロー
ス物質による成形体をその形状を保持したまま
炭化せしめた構造体の空隙部に充填した状態で
加熱すれば、これらの構造体は加熱時の収縮等
による変形がすでに炭化しているためほとんど
ないので、生成する上記のごとき空隙はおそら
く内部に分散され、加熱炉内の位置によらず
SiOやCOと接触する確率が均等に高くなり、
この結果生成するウイスカーの形状は均一に長
く、真直ぐに成長したものとなるのである。
(6) なお、含炭素組成物の嵩比重が、加熱前の状
態で0.2ｇ／c.c.が必要な理由も同様に理解され
る。すなわち、嵩比重が低いことはSiOやCO
の移動可能距離が長くなり、これらがウイスカ
ーの成長点に到達する確率が高くなるからであ
ろう。
〔産業上の利用可能性〕
本発明は工業的な方法で製造され、従つて高純
度で品質の一定した含炭素組成物を原料とする方
法であるため、従来のもみ穀を原料とする方法の
ように不純物や異物の混入は殆んどないことはも
ちろん、工業的規模の大型加熱炉を用いる場合に
おいても従来問題とされてきた湾曲の多いウイス
カーや微粒子状結晶を殆んど副生することなく真
直ぐに成長した長さ、太さが均等な勝れた形状の
炭化ケイ素ウイスカーを得ることができるので産
業上の利用可能性は極めて大きいといわねばなら
ない。
As described above, according to the present invention, it is possible to produce whiskers that grow straight and have an excellent shape with uniform length and thickness, without producing the short, curved whiskers and fine grain crystals that have been a problem in the past. It can be obtained extremely easily and with good reproducibility even in industrial scale equipment. Although the details of the reason are not necessarily clear, the inventors of the present invention tentatively speculate as follows. (1) The reaction in the formation of silicon carbide whiskers is expressed by the following formula. That is, gaseous SiO and CO are generated by the formula SiO 2 +C→SiO+CO … SiO+3CO→SiC+2CO 2 … CO 2 +C→2CO …, and as a result of the reaction of the formula, whiskers grow and by-products are generated. The resulting CO 2 is converted to CO by the formula
Return to Needless to say, the growth of SiC whiskers means that new SiC is generated at the growth point, and therefore the Si supplied to the growth point
And the C source needs to be in a gaseous state, such as SiO or CO. (2) In a carbon-containing composition, a silicon compound and a carbon compound are simultaneously charged into a hot gas, which are once vaporized and become a mixed state at the molecular level in the gas phase. Therefore, since the mixed state of these silicon oxides and elemental carbon is in a micro state unlike before, the reaction in the formula proceeds easily, and SiO and CO, which are SiC whisker sources, are Occurs in large numbers within. (3) During the whisker generation process, the apparent volume occupied by the carbon-containing composition in the heating furnace decreases due to the volatilization of some SiO and CO and due to the entanglement of the generated whiskers. A void is created. (4) SiO in the part facing the cavity and inside it
It is assumed that the probability of contact with CO and
If so, the former will be long and straight because this probability is high, but the latter will be short and curved because this probability is low. (5) Therefore, the carbon-containing composition is filled into the voids of the thin-walled breathable structure made of carbonaceous material of the present invention, particularly the molded body made of cellulose material, which is carbonized while maintaining its shape. If heated in this state, these structures will hardly be deformed due to shrinkage during heating because they are already carbonized, so the voids like the ones above will probably be dispersed inside, regardless of their position in the heating furnace.
The probability of contact with SiO and CO increases equally,
As a result, the shape of the whiskers produced is uniformly long and straight. (6) The reason why the bulk specific gravity of the carbon-containing composition is required to be 0.2 g/cc in the state before heating is similarly understood. In other words, low bulk specific gravity means that SiO and CO
This is probably because the distance that the whiskers can travel becomes longer and the probability that they reach the whisker growth point increases. [Industrial Applicability] The present invention is produced by an industrial method and uses a carbon-containing composition of high purity and constant quality as a raw material, so it is different from the conventional method using rice grain as a raw material. Not only is there almost no contamination of impurities or foreign substances, but there is almost no by-product of curly whiskers or fine particulate crystals, which have traditionally been a problem even when using large-scale industrial-scale heating furnaces. It must be said that the industrial applicability is extremely great because it is possible to obtain silicon carbide whiskers of excellent shape that are uniform in length and thickness and have grown straight without any problems.
第１図および第２図は走査型電子顕微鏡を用い
て撮影した炭化ケイ素ウイスカー結晶を示す写真
である。倍率は第１図第２図とも800倍である。
第３図は本発明の実施に使用する含炭素組成物を
得るための炉の１例を示す断面図である。第４図
は本発明において使用する通気性構造体を形成す
るための構造単位たる小片の形状の１例を示す斜
視図である。
図面において、１……炉材、２……ダクト、３
……燃焼バーナー、４……ノズル、５……ダクト
を示す。
FIGS. 1 and 2 are photographs showing silicon carbide whisker crystals taken using a scanning electron microscope. The magnification is 800x for both Figures 1 and 2.
FIG. 3 is a sectional view showing one example of a furnace for obtaining a carbon-containing composition used in the practice of the present invention. FIG. 4 is a perspective view showing an example of the shape of a small piece that is a structural unit for forming the breathable structure used in the present invention. In the drawings, 1...Furnace material, 2...Duct, 3
... combustion burner, 4 ... nozzle, 5 ... duct.
Claims (1)
及び炭素化合物を装入、分解して、ケイ素酸化物
及び単体炭素のそれぞれのエーロゾルを含む混合
エーロゾル分散質を生成せしめ、該生成した分散
質を固−気分離操作により捕集して得た嵩密度が
0.2ｇ／c.c.以下の含炭素組成物を1300〜1800℃に
加熱するに当り、該加熱部に連続的な空隙部を有
する通気性構造体を形成し、該含炭素組成物が該
構造体空隙部に充填された状態で該加熱を行う炭
化ケイ素ウイスカーの製造方法において、該通気
性構造体が薄肉の炭素質物質であることを特徴と
する炭化ケイ素ウイスカーの製造法。 ２ 通気性構造体が円柱、円筒、三角柱、三角
錐、四角柱、四角錐からなる群より選択される形
状の小片を構造単位として立体的に多数積み重ね
て構成される特許請求の範囲第１項記載の方法。 ３ 薄肉の炭素質物質が主成分がセルロース質で
ある薄肉の物質の炭化物である特許請求の範囲第
１項もしくは第２項に記載の方法。 ４ 含炭素組成物にアルカリ金属又はアルカリ土
類金属のハロゲン化物を添加する特許請求の範囲
第１項ないし第３項のいずれかに記載の方法。[Claims] 1. A decomposable silicon compound and a carbon compound are charged into a hot gas containing water vapor and decomposed to produce a mixed aerosol dispersoid containing aerosols of silicon oxide and elemental carbon, respectively. The bulk density obtained by collecting the generated dispersoid by solid-gas separation operation is
When heating a carbon-containing composition of 0.2 g/cc or less to 1300 to 1800°C, a breathable structure having continuous voids is formed in the heating section, and the carbon-containing composition fills the voids of the structure. 1. A method for producing silicon carbide whiskers in which the heating is performed in a state in which silicon carbide whiskers are filled in a container, wherein the air-permeable structure is a thin carbonaceous material. 2. Claim 1: The breathable structure is constructed by three-dimensionally stacking a large number of small pieces each having a shape selected from the group consisting of a cylinder, a cylinder, a triangular prism, a triangular pyramid, a quadrangular prism, and a quadrangular pyramid as a structural unit. Method described. 3. The method according to claim 1 or 2, wherein the thin carbonaceous material is a carbonized thin material whose main component is cellulose. 4. The method according to any one of claims 1 to 3, wherein an alkali metal or alkaline earth metal halide is added to the carbon-containing composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59221985A JPS61101500A (en) | 1984-10-24 | 1984-10-24 | Production of silicon carbide whisker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59221985A JPS61101500A (en) | 1984-10-24 | 1984-10-24 | Production of silicon carbide whisker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61101500A JPS61101500A (en) | 1986-05-20 |
| JPH0522678B2 true JPH0522678B2 (en) | 1993-03-30 |
Family
ID=16775264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59221985A Granted JPS61101500A (en) | 1984-10-24 | 1984-10-24 | Production of silicon carbide whisker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61101500A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0323300A (en) * | 1989-06-17 | 1991-01-31 | Toshiba Ceramics Co Ltd | Production of silicon carbide whisker |
| US5039501A (en) * | 1990-04-12 | 1991-08-13 | General Motors Corporation | Method for growing silicon carbide whiskers |
-
1984
- 1984-10-24 JP JP59221985A patent/JPS61101500A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61101500A (en) | 1986-05-20 |
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