JPS61259763A - Catalyst carrier made of porous silicon carbide sintered body - Google Patents
Catalyst carrier made of porous silicon carbide sintered bodyInfo
- Publication number
- JPS61259763A JPS61259763A JP60102298A JP10229885A JPS61259763A JP S61259763 A JPS61259763 A JP S61259763A JP 60102298 A JP60102298 A JP 60102298A JP 10229885 A JP10229885 A JP 10229885A JP S61259763 A JPS61259763 A JP S61259763A
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- sintered body
- aggregate
- catalyst carrier
- porous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 129
- 239000003054 catalyst Substances 0.000 title claims abstract description 70
- 229910021426 porous silicon Inorganic materials 0.000 title claims abstract description 28
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 82
- 239000013078 crystal Substances 0.000 claims abstract description 77
- 239000011148 porous material Substances 0.000 claims description 47
- 238000006243 chemical reaction Methods 0.000 abstract description 27
- 239000000126 substance Substances 0.000 abstract description 11
- 239000011247 coating layer Substances 0.000 abstract description 7
- 230000036632 reaction speed Effects 0.000 abstract 1
- 239000002245 particle Substances 0.000 description 40
- 238000010304 firing Methods 0.000 description 30
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 27
- 238000000034 method Methods 0.000 description 23
- 239000012530 fluid Substances 0.000 description 16
- 239000007858 starting material Substances 0.000 description 16
- 229910052799 carbon Inorganic materials 0.000 description 15
- 239000010410 layer Substances 0.000 description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 229910052782 aluminium Inorganic materials 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 238000000465 moulding Methods 0.000 description 9
- 239000007789 gas Substances 0.000 description 8
- 229910002804 graphite Inorganic materials 0.000 description 8
- 239000010439 graphite Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 238000005245 sintering Methods 0.000 description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 7
- 229910052804 chromium Inorganic materials 0.000 description 7
- 239000011651 chromium Substances 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 229910021417 amorphous silicon Inorganic materials 0.000 description 6
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000006260 foam Substances 0.000 description 6
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 239000000376 reactant Substances 0.000 description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 5
- 229910052796 boron Inorganic materials 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 229910052580 B4C Inorganic materials 0.000 description 4
- 229910052582 BN Inorganic materials 0.000 description 4
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 4
- CAVCGVPGBKGDTG-UHFFFAOYSA-N alumanylidynemethyl(alumanylidynemethylalumanylidenemethylidene)alumane Chemical compound [Al]#C[Al]=C=[Al]C#[Al] CAVCGVPGBKGDTG-UHFFFAOYSA-N 0.000 description 4
- 238000005452 bending Methods 0.000 description 4
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 4
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- QIJNJJZPYXGIQM-UHFFFAOYSA-N 1lambda4,2lambda4-dimolybdacyclopropa-1,2,3-triene Chemical compound [Mo]=C=[Mo] QIJNJJZPYXGIQM-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 239000005997 Calcium carbide Substances 0.000 description 3
- 229910039444 MoC Inorganic materials 0.000 description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- SJKRCWUQJZIWQB-UHFFFAOYSA-N azane;chromium Chemical compound N.[Cr] SJKRCWUQJZIWQB-UHFFFAOYSA-N 0.000 description 3
- 229910052810 boron oxide Inorganic materials 0.000 description 3
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 3
- 239000000292 calcium oxide Substances 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 3
- 239000000969 carrier Substances 0.000 description 3
- 229910001567 cementite Inorganic materials 0.000 description 3
- 229910000423 chromium oxide Inorganic materials 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 3
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- DEIVNMVWRDMSMJ-UHFFFAOYSA-N hydrogen peroxide;oxotitanium Chemical compound OO.[Ti]=O DEIVNMVWRDMSMJ-UHFFFAOYSA-N 0.000 description 3
- 229910052746 lanthanum Inorganic materials 0.000 description 3
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 3
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 3
- 229910001947 lithium oxide Inorganic materials 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 239000011733 molybdenum Substances 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 3
- CLZWAWBPWVRRGI-UHFFFAOYSA-N tert-butyl 2-[2-[2-[2-[bis[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]amino]-5-bromophenoxy]ethoxy]-4-methyl-n-[2-[(2-methylpropan-2-yl)oxy]-2-oxoethyl]anilino]acetate Chemical compound CC1=CC=C(N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)C(OCCOC=2C(=CC=C(Br)C=2)N(CC(=O)OC(C)(C)C)CC(=O)OC(C)(C)C)=C1 CLZWAWBPWVRRGI-UHFFFAOYSA-N 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 239000004408 titanium dioxide Substances 0.000 description 3
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011233 carbonaceous binding agent Substances 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- -1 for example Chemical compound 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 2
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- 229920002261 Corn starch Polymers 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229920001732 Lignosulfonate Polymers 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229910026551 ZrC Inorganic materials 0.000 description 1
- OTCHGXYCWNXDOA-UHFFFAOYSA-N [C].[Zr] Chemical compound [C].[Zr] OTCHGXYCWNXDOA-UHFFFAOYSA-N 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000011294 coal tar pitch Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000008120 corn starch Substances 0.000 description 1
- 229940099112 cornstarch Drugs 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000006261 foam material Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 239000011236 particulate material Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000001272 pressureless sintering Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 239000002296 pyrolytic carbon Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000011856 silicon-based particle Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 238000004017 vitrification Methods 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Landscapes
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は触媒担体に関し、特に高い強度ならびに優れた
通気性を有する多孔質炭化珪素焼結体からなる触媒担体
に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a catalyst carrier, and particularly to a catalyst carrier made of a porous silicon carbide sintered body having high strength and excellent air permeability.
（従来の技術）
化学反応を制御する触媒は、それ単体で使用されること
もあるが、通常は反応物質との接触面積を増大させて反
応効率を高めるために、この触媒を何かに担持させるこ
とがよく行なわれている。(Prior art) Catalysts that control chemical reactions are sometimes used alone, but they are usually supported on something to increase the contact area with reactants and improve reaction efficiency. It is common practice to do so.
ところで、酸化反応等の発熱反応を伴なう化学・反応に
あっては、触媒担体が高温に曝されるため耐熱性が要求
される。このような発熱反応を伴なう化学反応としては
、内燃機関、特にディーゼルエンジンの排気ガスを浄化
する場合の反応があげられる。触媒を使用してこのよう
な排気ガスの浄化を行なう場合には、その温度は相当高
いものになる。従って、排気ガスの浄化に使用される触
媒担体は、少なくともその高温に耐え得るものでなくて
はならない。By the way, in chemistry and reactions involving exothermic reactions such as oxidation reactions, heat resistance is required because the catalyst carrier is exposed to high temperatures. Examples of chemical reactions accompanied by such exothermic reactions include reactions for purifying exhaust gas from internal combustion engines, particularly diesel engines. When a catalyst is used to purify exhaust gas in this manner, the temperature thereof becomes considerably high. Therefore, the catalyst carrier used for exhaust gas purification must at least be able to withstand such high temperatures.
ところで、従来の触媒担体としては、Ａｎ、Ｏ，及びＳ
ｉＯ□等を主成分とする高い比表面積を有する多孔質体
として形成したものが知られている。ところが、このＡ
１，０．及びＳ ｉ Ｏ，等を主成分とする多孔質体
よりなる触媒担体は、１０００℃以上になると高温によ
って互いに焼結し易く、・予じめ高い比表面積を有した
ものとして形成しておいてもこの比表面積が低下してし
まうのである。また、Ａ ！Ｌ。By the way, conventional catalyst carriers include An, O, and S.
A porous material having a high specific surface area and containing iO□ as a main component is known. However, this A
1,0. Catalyst carriers made of porous bodies mainly composed of SiO, SiO, etc. tend to sinter with each other at high temperatures at temperatures above 1000°C. However, this specific surface area also decreases. Also, A! L.
０、及びＳ ｔ Ｏ，は熱伝導率が比較的低いため１発
熱反応に対しては局部的に高温となって担体が溶損し、
一度でもこのような状態になると触媒担体としての機能
が著しく劣化してしまう。0 and S t O, have relatively low thermal conductivity, so for a 1 exothermic reaction, local high temperatures will occur and the support will melt and be destroyed.
If such a state occurs even once, the function as a catalyst carrier will be significantly deteriorated.
また、触媒担体として要求される条件として、この触媒
担体中を反応物質が容易に通過し得るような構造のもの
でなければならないことがある。In addition, one of the conditions required for the catalyst carrier is that it must have a structure that allows the reactant to easily pass through the catalyst carrier.
物質の化学反応速度を早めるためには、反応物質が触媒
に接触し得る速度も早くなければならないからである。This is because in order to speed up the chemical reaction rate of a substance, the speed at which the reactant can contact the catalyst must also be fast.
要するに１発熱化学反応において使用される触媒担体と
して要求される特性は、少なくとも耐熱性があり１反応
物質の通過速度を遅延させることがないことである。In short, the characteristics required of a catalyst carrier used in an exothermic chemical reaction are that it has at least heat resistance and does not retard the passage rate of a reactant.
このような触媒担体として要求される特性を満足する物
質としては、炭化珪素が想起される。炭化珪素は、耐酸
化性、耐食性、良好な熱伝導率。Silicon carbide comes to mind as a material that satisfies the characteristics required for such a catalyst carrier. Silicon carbide has oxidation resistance, corrosion resistance, and good thermal conductivity.
低い熱膨張率、高温での高い強度等の化学的および物理
的に優れた性質を有するものであるから、上述のような
発熱反応を伴なう化学反応での触媒担体とするに適した
材料である。このような観点に立って前述のごとき触媒
担体として使用することができる炭化珪素質材料として
は、 ・■骨材となる炭化珪素粒子にガラス質フラック
ス、あるいは粘土質などの結合材を加えて成形した後、
その成形体を前記結合材が溶融する温度で焼き固めて製
造したもの
■粗大粒の炭化珪素粒子と微細な炭化珪素粒子を混合し
て成形した後、 ２０００℃以上の高温で焼成して製造
したもの
■特開昭４８−３９５１５号公報で開示されている「炭
化珪素粉に炭素粉を加え又は加えずに炭素質バインダー
を加えるとともに、この炭素粉及び焼成時に生成される
バインダーからの遊離炭素と反応する理論量の珪素質粉
を添加して形成し。It has excellent chemical and physical properties such as a low coefficient of thermal expansion and high strength at high temperatures, so it is a material suitable for use as a catalyst support in chemical reactions that involve exothermic reactions such as those mentioned above. It is. From this point of view, the silicon carbide materials that can be used as catalyst carriers as described above include: ・■Silicon carbide particles that serve as aggregates are formed by adding a binder such as vitreous flux or clay. After that,
Manufactured by baking and hardening the molded body at a temperature at which the binder melts ■ Manufactured by mixing coarse silicon carbide particles and fine silicon carbide particles, molding the mixture, and then firing it at a high temperature of 2000°C or higher. ``In addition to adding a carbonaceous binder to silicon carbide powder with or without addition of carbon powder, as disclosed in JP-A No. 48-39515, free carbon from this carbon powder and the binder generated during firing is Formed by adding a stoichiometric amount of siliceous powder to react.
しかる後この成形体の炭素粉中で１３σ０〜２４００℃
に加熱して成形体中の炭素分を珪素化することを特徴と
する均質多孔性再結晶炭化珪素体」が既に知られている
。After that, the molded body was heated at 13σ0 to 2400°C in the carbon powder.
"Homogeneous porous recrystallized silicon carbide body" is already known, which is characterized in that the carbon content in the molded body is silicified by heating to .
前記■のごとき結合材としてガラス質フラックスあるい
は粘土を加え製造した多孔質体にあっては、結合材が１
０００〜１４００℃で溶融するため、多孔質体はこの温
度域、特にガラス化転移温度付近で著しく強度が低下し
て変形するため、高い温度状態に曝される触媒担体とし
ては使用ができなくな □す、触媒担体としては
不十分なものとなる。In the case of a porous body manufactured by adding vitreous flux or clay as a binding material as in the above (①), the binding material is 1.
Since the porous material melts at temperatures between 000 and 1400°C, its strength significantly decreases and deforms in this temperature range, especially near the vitrification transition temperature, making it unusable as a catalyst carrier exposed to high temperatures. □It becomes insufficient as a catalyst carrier.
一方、■や■の方法で製造された多孔質体の構造をモデ
ル的に図示すれば第５図のようであり、炭化珪素質粒子
（３１）と粒子（３１）を被覆して、粒子（３１）同士
を結合する炭化珪素質結合材あるいは炭素質結合材（３
２）および間隙（３３）とから構成されている。この多
孔質体の間隙すなわち気孔はほとんど成形時に炭化珪素
粒子の配置によって決定され、焼結体中に占める気孔率
は３０〜４０％となり小さい、このため、この多孔質体
中を流れる流体が通過する際の抵抗は著しく高いものと
なる。これに対して、焼結体中の気孔率を大きくすると
炭化珪素粒子（３１）の接触点が少なくなり、多孔質体
の強度は著しく小さくなる傾向がある。On the other hand, if the structure of the porous body produced by the methods ① and ② is illustrated as a model, it is as shown in Fig. 5, in which silicon carbide particles (31) and particles (31) are coated, 31) Silicon carbide binder or carbonaceous binder (3
2) and a gap (33). The gaps, or pores, in this porous body are mostly determined by the arrangement of silicon carbide particles during molding, and the porosity in the sintered body is as small as 30 to 40%. Therefore, the fluid flowing through this porous body can pass through. The resistance when doing so is extremely high. On the other hand, when the porosity in the sintered body is increased, the number of contact points between silicon carbide particles (31) decreases, and the strength of the porous body tends to decrease significantly.
また、■および■の多孔質体における気孔径の制御は炭
化珪素の粒度配合により行なわれる。この方法によれば
、比較的大きい断面積を持つ気孔を有する多孔質体とす
るためには粒径の大きな炭化珪素粒子を必要とし、この
ため粒子の接触点が少なくなって粒子の結合強度が低下
するため、このような多孔質体によって形成した触媒担
体の強度は著しく低くなり、また比表面積も小さい、一
方、比較的小さい断面積を持つ気孔を有する多孔質体と
するためには、炭化珪素粒子の粒度配合を粗粒と中程度
の粒子、および／または微粒子と適度に混合し成形する
ことが必要であり、成形体の気孔率は著しく小さくなっ
て、極端な場合一部の気孔が閉塞してしまう傾向がある
。このため、このような多孔質体によって形成した触媒
担体中を流体が通過する際の抵抗は著しく高くなること
になる。Further, the pore size in the porous materials (1) and (2) is controlled by the particle size composition of silicon carbide. According to this method, silicon carbide particles with a large particle size are required to create a porous body with pores having a relatively large cross-sectional area, which reduces the number of contact points between the particles and reduces the bonding strength of the particles. As a result, the strength of the catalyst support formed by such a porous material is extremely low, and the specific surface area is also small. It is necessary to properly mix the particle size composition of silicon particles with coarse particles, medium particles, and/or fine particles before molding. It tends to get blocked. Therefore, the resistance when fluid passes through the catalyst carrier formed of such a porous material becomes significantly high.
また、比較的大きな気孔断面積を有する多孔質焼結体と
して１例えば特開昭５８−１２２０１６号公報によれば
、ｒ高分子発泡体材料に炭化珪素素地泥漿を含浸し、該
高分子発泡体材料を熱処理により消失せしめて炭化珪素
素地スケルトン構造体を形成し、該構造体を１９００〜
２３００℃の温度においてアルゴン中にて一次焼成し次
いで１８００〜２１００℃の温度にて１〜２００気圧の
窒素ガス中にて二次焼成した後その両端に耐熱電極を形
成し通電可能としてなる通電発熱可能な炭化珪素フィル
タの製造法、」が開示されており、また特開昭４８＝８
１９０５号公報によれば、「微細に粉砕されたセラミッ
ク材料を含むスラリーを有機質発泡体に含浸させ、こう
して含浸された発泡体を乾燥し、焼成し、その際発泡体
にスラリーを含浸させるに先立ち１発泡体はスラリー中
の粒子状材料が発泡構造物の表面に粘着するに至るよう
に処理されていることを特徴とする多孔質セラミック材
料の製造方法、」が開示されている。In addition, as a porous sintered body having a relatively large pore cross-sectional area, for example, according to JP-A-58-122016, a silicon carbide base slurry is impregnated into a r-polymer foam material. The material is eliminated by heat treatment to form a silicon carbide skeleton structure, and the structure is
After primary firing in argon at a temperature of 2300°C, and then secondary firing in a nitrogen gas of 1 to 200 atm at a temperature of 1800 to 2100°C, heat-resistant electrodes are formed on both ends of the electrode, making it possible to conduct electricity. A possible manufacturing method for a silicon carbide filter is disclosed, and also published in Japanese Patent Application Laid-Open No. 1988-8
According to the 1905 publication, "an organic foam is impregnated with a slurry containing finely ground ceramic material, and the thus impregnated foam is dried and fired, prior to impregnating the foam with the slurry. 1. A method for producing a porous ceramic material, wherein the foam is treated in such a way that the particulate material in the slurry adheres to the surface of the foam structure.
このような多孔質体は、第６図に示すような、いわゆる
スケルトン構造体と呼ばれる大小のセル状骨格（３４）
で構成されている。そのため、比較的大きいセル状骨格
（３４）で占められた場合、その多孔質体の気孔率を８
０〜８０容量％と高くでき、また流体の通過抵抗を小さ
くできる反面１強度は１０〜１５ｋｇ／ｃｒｎ”と低い
ものである。従って、このような ゝものから触
媒担体を形成した場合、実用的な面から見れば機械的強
度に乏しく、流体との接触面積は著しく小さい欠点があ
った。またこれらの製造方法によれば、ポリウレタン等
の高分子発泡体が構成する気泡は１１００１Ｌ以上のも
のになり易く、 ・それ以下の気孔を形成するこ
とは高分子の発泡性の制御、分散の点で非常に困難であ
り、また一部気孔の独立気孔化や内部空隙に対して隔壁
部に生じた連続気孔径が小さくなる場合があるので、こ
のようなもので形成した触媒担体中を流体を通過せしめ
るには通過抵抗が大となる欠点があった。Such porous bodies are composed of large and small cellular skeletons (34) called so-called skeleton structures, as shown in Figure 6.
It consists of Therefore, when occupied by a relatively large cellular skeleton (34), the porosity of the porous body is reduced to 8.
Although it can be made as high as 0 to 80% by volume and can reduce the fluid passage resistance, its strength is as low as 10 to 15 kg/crn. From a physical standpoint, they had the disadvantage of poor mechanical strength and a significantly small contact area with fluid.Furthermore, according to these manufacturing methods, the bubbles made up of polymeric foams such as polyurethane can exceed 11,001L.・It is extremely difficult to form smaller pores in terms of controlling and dispersing the foamability of the polymer, and some pores may become closed pores or may form at the partition wall due to internal voids. Since the diameter of continuous pores may be small, there is a drawback that passage resistance becomes large when a fluid is allowed to pass through a catalyst carrier formed of such a material.
（発明が解決しようとする問題点）
本発明は以上のような実状に鑑みてなされたもので、そ
の解決しようとする問題点は、特に発熱反応を伴なう化
学反応に際して使用される従来の −触媒担体にお
ける耐熱性の不十分さ、及び反応物質の触媒に接触する
場合の接触障害である。(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and the problems to be solved are particularly those of conventional methods used in chemical reactions involving exothermic reactions. - Insufficient heat resistance in the catalyst carrier and contact failure when the reactants come into contact with the catalyst.
そして１本発明の目的とするところは、耐熱性に優れし
かも必要十分な反応速度が得られる触媒担体を提供する
ことにある。One object of the present invention is to provide a catalyst carrier that has excellent heat resistance and can provide a necessary and sufficient reaction rate.
（問題点を解決するための手段）
以上の問題点を解決するために本発明が採った手段は、
主として炭化珪素よりなる焼結体であって、平均アスペ
クト比が３〜５０であり、かつ長軸方向の平均長さが０
．１〜１０００１Ｌｍの炭化珪素質板状結晶から構成さ
れてなる三次元網目構造を有し、この網目構造の開放気
孔の平均断面積が０．０１〜２５００００トゴである多
孔質の炭化珪素焼結体からなる骨材と、
この骨材の表面に触媒を担持し得るように形成した酸化
物被膜層と
により構成したことを特徴とする多孔質炭化珪素焼結体
からなる触媒担体
である。(Means for Solving the Problems) The means taken by the present invention to solve the above problems is a sintered body mainly made of silicon carbide, having an average aspect ratio of 3 to 50, and Average length in major axis direction is 0
．． A porous silicon carbide sintered body having a three-dimensional network structure composed of silicon carbide plate crystals of 1 to 10,001 Lm, and the average cross-sectional area of the open pores of this network structure is 0.01 to 250,000 Lm. This is a catalyst carrier made of a porous silicon carbide sintered body, characterized in that it is made up of an aggregate made of the following: and an oxide film layer formed on the surface of the aggregate to support a catalyst.
以下に１本発明に係る多孔質炭化珪素焼結体からなる触
媒担体な詳細に説明する。Below, a catalyst carrier made of a porous silicon carbide sintered body according to the present invention will be explained in detail.
第１図には、本発明に係る触媒担体（１０）の斜視図が
示してあり、第２図には第１図の要部拡大断面図である
。この触媒担体（ｌＯ）は、例えば第２図に示した如き
多孔質炭化珪素焼結体によって形成された骨材（１１）
と、この骨材（１１）を構成する三次元網目構造の炭化
珪素焼結体の表面に形成した酸化物被膜層（１３）とか
らなるもので、この酸化物被膜層（１３）の表面に触媒
が担持されるのである。そして、当該触媒担体（１０）
の骨材（１１）は、一定方向 □の多数の通気孔
（１２）を形成することによってハニカム構造としであ
る。FIG. 1 shows a perspective view of a catalyst carrier (10) according to the present invention, and FIG. 2 is an enlarged sectional view of the main part of FIG. 1. This catalyst carrier (lO) is made of an aggregate (11) formed of a porous silicon carbide sintered body as shown in FIG. 2, for example.
and an oxide film layer (13) formed on the surface of the three-dimensional network structured silicon carbide sintered body constituting the aggregate (11). The catalyst is supported. And the catalyst carrier (10)
The aggregate (11) is formed into a honeycomb structure by forming a large number of ventilation holes (12) in a certain direction □.
第３図は本発明に係る触媒担体（１０）の骨材（１１）
を構成している一つの多孔質炭化珪素焼結体の結晶構造
の走査型電子顕微鏡写真（Ｘ ３５）である。Figure 3 shows the aggregate (11) of the catalyst carrier (10) according to the present invention.
This is a scanning electron micrograph (X 35) of the crystal structure of one porous silicon carbide sintered body constituting the.
図面から明らかなように、触媒担体（１０）の骨材（１
ｉｌ）は、アスペクト比が１０〜２０．長さが約５０
１１０１Ｌに及ぶ炭化珪素質板状結晶が多方向に複
雑に絡み合った三次元網目構造を有し、さらに気孔が連
続しかつ直−線的でない開放気孔であって、しかも通気
性に富んだものとなっている。ここでいう炭化珪素質板
状結晶の長さとは、結晶体の任意の断面において観察さ
れる個々の板状結晶の最大長さくＸ）であり、同様に個
々の板状結晶のアスペクト比（Ｒ）は板状結晶の最大厚
み（Ｙ）と前記結晶長さくＸ）との比として、すなわち
、Ｒ＝Ｘ／Ｙ
で表わされる。As is clear from the drawing, the aggregate (1) of the catalyst carrier (10)
il) has an aspect ratio of 10 to 20. Approximately 50 long
It has a three-dimensional network structure in which 1101 L of silicon carbide plate crystals are complicatedly intertwined in multiple directions, and the pores are continuous and non-linear open pores, and are highly breathable. It has become. The length of the silicon carbide plate crystals here refers to the maximum length (X) of each plate crystal observed in any cross section of the crystal, and similarly, the aspect ratio (R ) is expressed as the ratio of the maximum thickness (Y) of the plate-shaped crystal to the crystal length (X), that is, R=X/Y.
本発明に係る触媒相体（１Ｇ）の骨材（！りは、平均ア
スペクト比が３〜５０の炭化珪素板状結晶で構成された
三次元の網目構造となっていることが特徴である。この
骨材（１１）を構成する炭化珪素板状結晶の平均アスペ
クト比を３以上とする理由は、炭化珪素質板状結晶によ
って構成される気孔が、結晶の占める容積に比べて大き
な多孔質体、すなわち高い気孔率を有する多孔質体とな
すためである。なお、従来の多孔質炭化珪素焼結体は第
５図に示したように成形時の炭化珪素粒子の配置によ
′シ
って決定されており２本発明に係る骨材（１１）の如き
板状結晶が発達した多孔質体と異なり、その結晶のアス
ペクト比はせいぜい２前後にすぎず、高い気孔率あるい
は大きな気孔断面積１有してはいない。The aggregate of the catalyst phase (1G) according to the present invention is characterized by having a three-dimensional network structure composed of silicon carbide plate crystals having an average aspect ratio of 3 to 50. The reason why the average aspect ratio of the silicon carbide plate crystals constituting this aggregate (11) is set to 3 or more is that the pores formed by the silicon carbide plate crystals are large compared to the volume occupied by the crystals. In other words, this is to create a porous body with high porosity.As shown in Figure 5, conventional porous silicon carbide sintered bodies are
2 Unlike porous materials with developed plate-like crystals such as the aggregate (11) according to the present invention, the aspect ratio of the crystals is only around 2 at most, and the porosity is high or large. It does not have a pore cross-sectional area of 1.
一方本発明に係る骨材（１１）である多孔質体の平均ア
スペクト比を５０以下とする理由は、平均アスペクト比
が５０よりも大きい板状結晶で構成された多孔質体は結
晶相互の接合部が少ないため、多孔質自体の強度が低い
からである。なかでも、前記板状結晶の平均アスペクト
比は５〜３０であることがより好適であり、この範囲内
で本発明に係る骨材（１１）はその多孔質体としての構
造を適宜選択することができる。On the other hand, the reason why the average aspect ratio of the porous body which is the aggregate (11) according to the present invention is set to 50 or less is that a porous body composed of plate-shaped crystals with an average aspect ratio larger than 50 has a bond between the crystals. This is because the strength of the porous material itself is low due to the small amount of porous material. Among these, it is more preferable that the average aspect ratio of the plate crystals is 5 to 30, and within this range, the structure of the aggregate (11) according to the present invention as a porous body should be appropriately selected. I can do it.
また、骨材（１１）を構成する板状結晶の長軸方向の平
均長さは０，５〜ｌｏ００ＩＬｍであることが必要であ
る。その理由は、長軸方向の平均長さが０．５終ｍより
小さいと、前記板状結晶により形成される気孔が小さく
、場合によっては気孔の一部が独立気孔になっているこ
とがあり、当該骨材（１１）を通過する流体の通過抵抗
が大きくなるためである。Further, the average length of the plate-shaped crystals constituting the aggregate (11) in the long axis direction needs to be 0.5 to lo00ILm. The reason is that when the average length in the major axis direction is smaller than 0.5 m, the pores formed by the plate-like crystals are small, and in some cases, some of the pores may become independent pores. This is because the passage resistance of the fluid passing through the aggregate (11) increases.
一方、１１０００１Ｌより長くなると、板状結晶の接合
部の強度が小さく、多孔質体自体の強度が低くなるため
である。なかでも、前記板状結晶の長軸方向の平均長さ
は１〜８００μｍであることがより好適であり、この範
囲内で本発明に係る骨材（１１）はその多孔質体として
の構造を適宜選択することができる。On the other hand, if the length is longer than 110001L, the strength of the joint between the plate crystals will be low, and the strength of the porous body itself will be low. Among these, it is more preferable that the average length of the plate crystals in the long axis direction is 1 to 800 μm, and within this range, the aggregate (11) according to the present invention has a structure as a porous body. It can be selected as appropriate.
また、前記網目構造の開放気孔の平均断面積は０．０１
〜２５００００ ｐ−ゴであることが必要である。その
理由は、開放気孔の平均断面積が０．Ｏｌルゴ以下であ
ると、開放気孔を通過する流体の通過抵抗が大きくなる
ためである。一方、開放気孔の平均断面積が２５０００
０４ ｒｒｌ”より大きいと、多孔質体自体の強度が低
く、なかでも前記網目構造の開放気孔の平均断面積は０
．２５〜９００００ ｐ−ゴであることがより好ましく
、この範囲内で本発明に係る骨材（１１）はその多孔質
体としての構造を適宜選択することができる。Further, the average cross-sectional area of the open pores of the network structure is 0.01
~250,000 p-go is required. The reason is that the average cross-sectional area of open pores is 0. This is because if it is less than 100 ml, the passage resistance of fluid passing through the open pores becomes large. On the other hand, the average cross-sectional area of open pores is 25,000
If it is larger than 04 rrl, the strength of the porous body itself is low, and in particular, the average cross-sectional area of the open pores in the network structure is 0.
．． 25 to 90,000 p-go is more preferable, and within this range, the structure of the aggregate (11) according to the present invention as a porous body can be appropriately selected.
そして、前記多孔質体の結晶１００重量部のうち３〜５
０のアスペクト比を有する板状結晶は少なくとも２０重
量部を占めることが好ましい、ところで、前記板状結晶
の含有量は結晶の構造写真を解析することにより求めら
れる。ここで、前記多孔質体が２０重量部以上の３〜５
０のアスペクト比を有する板状結晶で占められているこ
とが好ましい理由は、前記板状結晶が２０重量部より少
ないと、アスペクト比の小さい炭化珪素結晶が多く含ま
れることになり、流体の通過抵抗が大きくなるからであ
る。なかでも、前記板状結晶は前記多孔質体の結晶１０
０重量部のうち少なくとも４０重量部を占めることが有
利である。Of the 100 parts by weight of crystals in the porous body, 3 to 5 parts by weight
It is preferable that plate crystals having an aspect ratio of 0 account for at least 20 parts by weight. Incidentally, the content of the plate crystals is determined by analyzing a structural photograph of the crystal. Here, the porous body is 3 to 5 parts by weight or more of 20 parts by weight or more.
The reason why it is preferable that the plate crystals are occupied by plate crystals having an aspect ratio of 0 is that if the plate crystals are less than 20 parts by weight, a large amount of silicon carbide crystals with a small aspect ratio will be included, and the passage of the fluid will be reduced. This is because the resistance increases. Among them, the plate crystals are crystals 10 of the porous body.
Advantageously, it accounts for at least 40 parts by weight out of 0 parts by weight.
そして、骨材（１１）となる多孔質炭化珪素焼結体の開
放気孔率は焼結体の全容積に対し２０〜９５容量％、な
かでも３０〜９０容量％であることが好ましい、その理
由は、開放気孔率が２０容量％よりも小さいと気孔の一
部が独立気孔であり、流体が骨材（１１）を通過すると
きの抵抗が大きく、また流体と接触する面積が小さくな
るためである。The reason why the open porosity of the porous silicon carbide sintered body serving as the aggregate (11) is preferably 20 to 95% by volume, particularly 30 to 90% by volume, based on the total volume of the sintered body. This is because when the open porosity is less than 20% by volume, some of the pores are independent, and the resistance when the fluid passes through the aggregate (11) is large, and the area in contact with the fluid is small. be.
一方、９５容量％よりも大きいと流体との接触面積は大
きい半面、前記多孔質焼結体の強度が低くなって触媒担
体としての使用が困難となるためである。On the other hand, if it is larger than 95% by volume, the contact area with the fluid will be large, but the strength of the porous sintered body will be low, making it difficult to use it as a catalyst carrier.
そして、前記炭化珪素焼結体の比表面積は少なくとも０
．０５ｍ” ／ ｇ以上であることが好ましい、ここで
比表面積は窒素吸着によるＢＥＴ法によって求められる
値である。比表面積が０．０５ｍ″／ｇ以上が好ましい
理由は、触媒担体の用途では焼結体と流体との接触面積
が多い方が好ましいためであり、なかでもこの触媒担体
としての用途に対しては少なくとも０．２ゴ／ｇの比表
面積であることが最も好適である。The specific surface area of the silicon carbide sintered body is at least 0.
．． The specific surface area is preferably determined by the BET method using nitrogen adsorption.The reason why the specific surface area is preferably 0.05 m''/g or more is because sintering This is because it is preferable to have a large contact area between the body and the fluid, and in particular, a specific surface area of at least 0.2 g/g is most preferable for use as a catalyst carrier.
次に１本発明に係る骨材（１１）を構成する多孔質炭化
珪素焼結体の製造方法について説明する。この場合の製
造方法は次の各工程からなる。すなわち、
（ａ）平均粒径が１０μｍ以下の炭化珪素粉末であって
β型、２Ｈ型および非晶質の炭化珪素を少なくとも６０
重量％含有する炭化珪素粉末を所望の形状に成形する工
程：および
（ｂ）前記（ａ）工程により得られた成形体を炭化珪素
の揮発を抑制しつつ１３００〜２３００℃の温度範囲内
で焼成する工程；
によって長軸方向の平均長さがｌＧ〜１０００ ｐ−ｍ
、千 ′均アスペクト比が３〜５０の炭化珪素質
板状結晶から主として構成されてなる三次元網目構造を
有し、前記網目構造の開放気孔の平均断面積が４００〜
２５００００ ｐ ｒｎ’の範囲内の平均断面積を有す
る多孔質炭化珪素焼結体を得ることができる。Next, a method for manufacturing a porous silicon carbide sintered body constituting the aggregate (11) according to the present invention will be described. The manufacturing method in this case consists of the following steps. That is, (a) at least 60 μm of β-type, 2H-type, and amorphous silicon carbide powder having an average particle size of 10 μm or less;
A step of molding the silicon carbide powder containing % by weight into a desired shape: and (b) firing the molded body obtained in step (a) within a temperature range of 1300 to 2300° C. while suppressing volatilization of silicon carbide. Step of
, has a three-dimensional network structure mainly composed of silicon carbide plate crystals with an average aspect ratio of 3 to 50, and has an average cross-sectional area of open pores in the network structure of 400 to 50.
A porous silicon carbide sintered body having an average cross-sectional area in the range of 250,000 p rn' can be obtained.
この方法によれば、出発原料は少なくとも８０重量％の
β型、２Ｈ型および非晶質の炭化珪素焼結体を含有する
炭化珪素を出発原料の１つとすることが必要である。こ
の理由はβ型結晶、 ２Ｈ型結晶および非晶質の炭化珪
素結晶は比較的低温で合成される低温安定型結晶であり
、焼結に際しその一部が４Ｈ，６Ｈあるいは１５Ｒ型等
の高温安定型α型結晶に相転移して、板状結晶を生じや
すいばかりでなく、結晶の成長性にも優れた特性を有し
、特に６０重量％以上のβ型炭化珪素からなる出発原料
を用いることによって、本発明に係る骨材（１１）とし
ての多孔質体を製造することができるからである。なか
でも、少なくとも７０重量％のβ型、２Ｈ型および非晶
質炭化珪素を含有する出発原料を用いることが好適であ
る。According to this method, one of the starting materials needs to be silicon carbide containing at least 80% by weight of β-type, 2H-type and amorphous silicon carbide sintered bodies. The reason for this is that β-type crystals, 2H-type crystals, and amorphous silicon carbide crystals are low-temperature stable crystals that are synthesized at relatively low temperatures, and during sintering, some of them become high-temperature stable crystals such as 4H, 6H, or 15R types. Use a starting material that not only easily undergoes a phase transition to α-type crystals to form plate-like crystals, but also has excellent crystal growth properties, and in particular consists of 60% by weight or more of β-type silicon carbide. This is because the porous body as the aggregate (11) according to the present invention can be manufactured by this method. Among these, it is preferable to use a starting material containing at least 70% by weight of β-type, 2H-type, and amorphous silicon carbide.
そして、前記出発原料は平均粒径がｌｏＪＬｍ以下の微
粉末であることが必要である。平均粒径が１０ ＃Ｌｍ
よりも小さい粉末は、粒子相互の接触点が比較的多く、
また炭化珪素の焼成温度において熱的活性が大であり、
炭化珪素粒子間での原子の移動が著しく大きいため、炭
化珪素粒子相互の結合が極めて起こりやすい、従って、
板状結晶の成長性が著しく高い、特に、前記出発原料の
平均粒径は５ＩＬｍ以下であることが板状結晶の成長性
により好ましい結果を与える。The starting material needs to be a fine powder with an average particle size of loJLm or less. Average particle size is 10 #Lm
Powders smaller than , have relatively more points of contact between particles;
In addition, the thermal activity is large at the firing temperature of silicon carbide,
Since the movement of atoms between silicon carbide particles is extremely large, bonding between silicon carbide particles is extremely likely to occur.
The growth property of plate crystals is extremely high. In particular, it is preferable that the average particle size of the starting material is 5 ILm or less, which gives more favorable results in the growth property of plate crystals.
前記出発原料を所望の形状の生成形体として形成する方
法としては１種々の方法を適用することができ、例えば
加圧成形、鋳込成形、射出成形等を有利に適用すること
ができる。Various methods can be used to form the starting material into a product having a desired shape, and for example, pressure molding, cast molding, injection molding, etc. can be advantageously applied.
そして、前記所望の形状に成形された生成形体は、焼成
中に生ずる生成形体からの炭化珪素の揮 □発を
充分に抑制することのできる条件で、１９００〜２３０
０℃の温度範囲内で焼成することが必要である、このよ
うに、炭化珪素の揮発を充分に抑制することのできる条
件で焼成を行なう理由は、隣接する炭化珪素粒子同志の
結合、および板状結晶の成長を促進させることができる
からである。前述の如く炭化珪素の揮発を充分に抑制し
て焼成することによって、隣接する炭化珪素粒子同志の
結合および板状結晶の成長を促進させることのできる理
由は、炭化珪素粒子間における炭化珪素の蒸発・再凝縮
および／または表面拡散による移動を促進することがで
きるためと考えられる。The formed body formed into the desired shape is heated to a temperature of 1900 to 230 □ under conditions that can sufficiently suppress volatilization of silicon carbide from the formed body produced during firing.
It is necessary to perform the firing within the temperature range of 0°C.The reason for performing the firing under conditions that can sufficiently suppress the volatilization of silicon carbide is to prevent the bonding of adjacent silicon carbide particles and the formation of the plate. This is because the growth of crystals can be promoted. As mentioned above, the reason why the bond between adjacent silicon carbide particles and the growth of plate-like crystals can be promoted by firing while sufficiently suppressing the volatilization of silicon carbide is due to the evaporation of silicon carbide between the silicon carbide particles. - This is thought to be because movement due to recondensation and/or surface diffusion can be promoted.
前記炭化珪素の揮発を充分に抑制して焼成を行なう手段
としては、たとえば黒鉛、炭化珪素炭化珪素、炭化タン
グステン、モリブデン、炭化モリブデン等の耐熱性の容
器内に装入して外気の侵入を遮断しつつ焼成する手段が
適用できる。なお、この方法においては、炭化珪素の揮
発量が５重量％以下になるように制御して焼成すること
が好ましい、これに対し、従来知られている常圧焼結、
雰囲気加圧焼結あるいは減圧下における焼結法を試みた
ところ、板状結晶の成長が困難であるばかりでなく、炭
化珪素粒子の接合部がネック状にくびれだ形状となり、
焼結体の強度が低くなった。As a means for performing firing while sufficiently suppressing the volatilization of the silicon carbide, for example, silicon carbide is charged into a heat-resistant container made of graphite, silicon carbide, tungsten carbide, molybdenum, molybdenum carbide, etc. to block the intrusion of outside air. It is possible to apply a method of firing while heating. In addition, in this method, it is preferable to control the firing so that the amount of volatilization of silicon carbide is 5% by weight or less.In contrast, conventional pressureless sintering,
When atmospheric pressure sintering or sintering under reduced pressure was attempted, not only was it difficult to grow plate-shaped crystals, but the joints of silicon carbide particles became constricted into a neck-like shape.
The strength of the sintered body became low.
′また、本発明に係る骨材（！りを構成する多孔質体の
製造方法において、比較的大きな平均断面積の開放気孔
を有する多孔質体を得るには、焼成時の昇温速度が比較
的ゆっくりとした状態で焼成すること、最高温度を比較
的高くすることおよび／または最高温度での保持時間を
長くすることが好ましい、この条件によれば２個々の炭
化珪素の板状結晶を大きく成長させることができ、その
結果大きな気孔断面積を有する多孔質体を得ることがで
きる。'Furthermore, in the method for producing a porous body constituting the aggregate according to the present invention, in order to obtain a porous body having open pores with a relatively large average cross-sectional area, the temperature increase rate during firing must be relatively high. It is preferable to sinter in a slow state, to make the maximum temperature relatively high, and/or to extend the holding time at the maximum temperature. According to these conditions, two individual plate-shaped crystals of silicon carbide can be made large. As a result, a porous body with a large pore cross-sectional area can be obtained.
これとは逆に、本発明に係る骨材（１１）を構成する多
孔質体゛として、すなわち比較的小さな平均断面積の開
放気孔を有する多孔質体を得るには、焼成時の昇温速度
を比較的速くすること、最高温度を比較的小さくするこ
と、および／または最高温度における保持時間を短くす
ることが好ましい。On the contrary, in order to obtain a porous body constituting the aggregate (11) according to the present invention, that is, a porous body having open pores with a relatively small average cross-sectional area, it is necessary to It is preferable to have a relatively fast temperature, a relatively small maximum temperature, and/or a short holding time at the maximum temperature.
この条件によれば、個々の炭化珪素の板状結晶をそれ程
成長させることがないからである。This is because, under these conditions, individual plate-shaped crystals of silicon carbide are not allowed to grow to a large extent.
また上記方法においては、生成形体を１３００〜２３０
０℃の温度範囲内で焼成することが必要である。In addition, in the above method, the formed body is 1300 to 230
It is necessary to fire within the temperature range of 0°C.
この理由は、焼成温度が１８００℃よりも低いと粒子の
成長が不十分となって、高い強度を有する多孔質体を有
することが困難であり、２３００℃よりも高い温度にな
ると炭化珪素の昇華が盛んになり、発達した板状結晶が
逆にやせ細ってしまい、その結果高い強度を持った多孔
質体を得ることが困難となるためである。The reason for this is that if the firing temperature is lower than 1800°C, particle growth will be insufficient, making it difficult to have a porous body with high strength, and if the firing temperature is higher than 2300°C, silicon carbide will sublimate. This is because the plate-like crystals that have developed become thinner and thinner, making it difficult to obtain a porous body with high strength.
さらに、次のような方法によっても、骨材（１１）を構
成する多孔質炭化珪素焼結体を得ることができる。Furthermore, the porous silicon carbide sintered body constituting the aggregate (11) can also be obtained by the following method.
（ａ）平均粒径が１１０７ｚ以下の炭化珪素粉末であっ
て、かつこの粉末はα型、β型および／または非晶質炭
化珪素と不可避的不純物とからなる炭化珪素粉末である
出発原料であって、この粉末１００重量部に対し、アル
ミニウム、ニホウ化アルミニウム、炭化アルミニウム、
窒化アルミニウム、酸化アルミニウム、ホウ素、炭化ホ
ウ素、窒化ホウ素、酸化ホウ素、酸化カルシウム、炭化
カルシウム、クロム、ホウ化クロム、窒化クロム、酸化
クロム、鉄、炭化鉄、酸化鉄、ホウ化ランタン、酸化ラ
ンタン、酸化リチウム、珪素、窒化珪素、チタン、酸化
チタン、二酸化チタン、三酸化チタンおよび酸化イツト
リウムのなかから選ばれるいずれか１種または２種以上
の１０重量部以下を均一に混合する工程；
（ｂ）前記（ａ）工程により得られた混合物を成型する
工程：および
（ｃ）前記（ｂ）工程により得られた成形体を炭化珪素
の揮発を抑制しつつ１７００〜２３００℃の温度範囲内
で焼成する工程：
により、長軸方向の平均長さが０．５〜２００ＩＬｍ、
平均アスペクト比が３〜５０の炭化珪素板状結晶から主
として構成されてなる三次元網目構造を有し、前記網目
構造の開放気孔の平均断面積が０．０１〜１００００
Ｊｚｍ’の範囲内の平均断面積を有する多孔質炭化珪素
焼結体を得ることができる。(a) A starting material which is a silicon carbide powder having an average particle size of 1107z or less, and this powder is a silicon carbide powder consisting of α-type, β-type and/or amorphous silicon carbide and inevitable impurities. For 100 parts by weight of this powder, aluminum, aluminum diboride, aluminum carbide,
Aluminum nitride, aluminum oxide, boron, boron carbide, boron nitride, boron oxide, calcium oxide, calcium carbide, chromium, chromium boride, chromium nitride, chromium oxide, iron, iron carbide, iron oxide, lanthanum boride, lanthanum oxide, A step of uniformly mixing 10 parts by weight or less of any one or more selected from lithium oxide, silicon, silicon nitride, titanium, titanium oxide, titanium dioxide, titanium trioxide, and yttrium oxide; (b) A step of molding the mixture obtained in step (a) above: and (c) firing the molded body obtained in step (b) above within a temperature range of 1700 to 2300° C. while suppressing volatilization of silicon carbide. Process: The average length in the major axis direction is 0.5 to 200 ILm,
It has a three-dimensional network structure mainly composed of silicon carbide plate crystals with an average aspect ratio of 3 to 50, and the average cross-sectional area of open pores in the network structure is 0.01 to 10,000.
A porous silicon carbide sintered body having an average cross-sectional area within the range of Jzm' can be obtained.
上記の方法によれば、骨材（１１）を構成するための出
発原料は、平均粒径が１０μｍ以下の炭化珪素微粉末で
あることが必要である。平均粒径が１０μｍよりも小さ
い粉末は、粒子相互の接触点が比較的多く、また炭化珪
素の焼成温度において熱的活性が大であり、炭化珪素粒
子間での原子の移動が著しく大きいため、炭化珪素粒子
相互の結合が極めて起こりやすい、従って、板状結晶の
成長性が著しく高い、特に、前記出発原料の平均粒径は
５ＩＬｍ以下であることが板状結晶の成長性により好ま
しい結果を与える。According to the above method, the starting material for constituting the aggregate (11) needs to be silicon carbide fine powder with an average particle size of 10 μm or less. Powders with an average particle size of less than 10 μm have a relatively large number of contact points between the particles, and are highly thermally active at the sintering temperature of silicon carbide, and the movement of atoms between silicon carbide particles is extremely large. Silicon carbide particles are extremely likely to bond with each other, and therefore, the growth of plate crystals is extremely high.In particular, it is preferable that the average particle size of the starting material is 5 ILm or less, which gives more favorable results for the growth of plate crystals. .
また上記の方法にあっては、アルミニウム、ニホウ化ア
ルミニウム、炭化アルミニウム窒化アルミニウム、酸化
アルミニウム、ホウ素、炭化ホウ素、窒化ホウ素、酸化
ホウ素、酸化カルシウム、炭化カルシウム、クロム、ホ
ウ化クロム、窒化クロム、酸化クロム、鉄、炭化鉄、ホ
ウ化ランタン、酸化ランタン、酸化リチウム、ケイ素、
窒化ケイ素、チタン、酸化チタン、二酸化チタン、三酸
化チタンおよび酸化イツトリウムの中から選ばれるいず
れか１種または２種以上を添加することが必要であり、
これらの物質は炭化珪素の結晶成長の速度を著しく高め
る働きがある。また、これらの各物質を添加する理由は
、は前記炭化珪素成形体の焼成温度１７００〜２３００
℃において各物質の蒸気 □”および／または分
解生成物の蒸気を生成して前記炭化珪素成形体のすみず
みまで拡散し、これによ □′：：〒
って極めて多くの板状結晶の核を形成して各々の
、バ部分で板状結晶の発達を促がし、その結果形成さ
□“れる板状結晶の大きさを制限して細かい組
織の三次元網目構造とするためである。前記化合物のう
ち、特にホウ素、炭化ホウ素、窒化ホウ素、酸化アルミ
ニウム、窒化アルミニウム、炭化アルミニウム、ニホウ
化アルミニウム、アルミニウムを有利に使用することが
できる。In the above method, aluminum, aluminum diboride, aluminum carbide, aluminum nitride, aluminum oxide, boron, boron carbide, boron nitride, boron oxide, calcium oxide, calcium carbide, chromium, chromium boride, chromium nitride, chromium oxide, Chromium, iron, iron carbide, lanthanum boride, lanthanum oxide, lithium oxide, silicon,
It is necessary to add one or more selected from silicon nitride, titanium, titanium oxide, titanium dioxide, titanium trioxide, and yttrium oxide,
These substances have the function of significantly increasing the rate of crystal growth of silicon carbide. Moreover, the reason for adding each of these substances is that the firing temperature of the silicon carbide molded body is 1700 to 2300.
At ℃, vapors of each substance □'' and/or vapors of decomposition products are generated and diffused to every corner of the silicon carbide molded body. to form each
This is to promote the development of plate-like crystals in the □" part, thereby limiting the size of the plate-like crystals that are formed and forming a three-dimensional network structure with a fine structure. Among the above compounds, especially Boron, boron carbide, boron nitride, aluminum oxide, aluminum nitride, aluminum carbide, aluminum diboride, aluminum can be used advantageously.
一方、前記物質の添加量は前記炭化珪素を主体としてな
る出発原料１００重量部に対し、１０重量部以下である
ことが必要である。その理由は、１０重量部よりも多く
添加しても、前記炭化珪素成形体の焼成温度範囲内にお
いて前記物質および／またはその分解生成物の蒸気分圧
はほとんど変らない、逆に前記物質が前記成形体内で残
留する量が多くなるため炭化珪素本来の特性が失われる
からであり、さらに板状結晶の成長に適した前記物質の
添加量は炭化珪素出発原料１００重量部に対し、５重量
部以下が好適でる。On the other hand, the amount of the substance added needs to be 10 parts by weight or less with respect to 100 parts by weight of the starting material mainly consisting of silicon carbide. The reason for this is that even if more than 10 parts by weight is added, the vapor partial pressure of the substance and/or its decomposition products hardly changes within the firing temperature range of the silicon carbide molded body; This is because the original properties of silicon carbide are lost due to the large amount remaining in the molded body, and the addition amount of the substance suitable for the growth of plate crystals is 5 parts by weight per 100 parts by weight of the silicon carbide starting material. The following are suitable.
また、前記出発原料として使用される炭化珪素はα型、
β型および／または非晶質炭化珪素のいずれも使用する
ことができる。Furthermore, the silicon carbide used as the starting material is α-type,
Either β-type and/or amorphous silicon carbide can be used.
上記の方法によれば焼成時に遊離カーボンを残す炭素源
を添加することができる。このような炭素源としては、
焼結開始時に炭素の状態で存在するものであれば使用す
ることができ、例えばフェノール樹脂、リグニンスルホ
ン酸塩、ポリビニルアルコール、コンスターチ、糖類、
コールタールピッチ、アルギン酸塩のような各種有機物
質あるいはカーボンブラック、アセチレンブラックのよ
うな熱分解炭素を有利に使用することができる。According to the above method, it is possible to add a carbon source that leaves free carbon during firing. Such carbon sources include
Any material that exists in a carbon state at the start of sintering can be used, such as phenolic resin, lignin sulfonate, polyvinyl alcohol, cornstarch, saccharide,
Various organic substances such as coal tar pitch, alginates or pyrolytic carbons such as carbon black, acetylene black can be advantageously used.
遊離カーボンは前記物質と同時に存在すると結晶の成長
性を抑え、微細な炭化珪素質板状結晶を形成するため、
微細な気孔を有する多孔質体を得るのに効果がある。When free carbon exists simultaneously with the above substances, it suppresses crystal growth and forms fine silicon carbide plate crystals.
It is effective in obtaining a porous body having fine pores.
また、前記遊離炭素分としては出発原料１００重量部に
対し、５重量部以下であることが有利である。その理由
は、５重量部より多く添加してもその効果は変らず、逆
に前記多孔質体に残留する量が多くなって粒子と粒子と
の結合を阻害するた □め多孔質体の強度が劣化す
るためであり、なかでも３重量部以下であることがより
効果的である。Further, it is advantageous that the free carbon content is 5 parts by weight or less based on 100 parts by weight of the starting material. The reason for this is that even if more than 5 parts by weight is added, the effect does not change, but on the contrary, the amount remaining in the porous body increases and inhibits the bonding between particles, thereby increasing the strength of the porous body. This is because the amount deteriorates, and it is particularly effective to keep the amount at 3 parts by weight or less.
上記の方法によれば、前記炭化珪素の揮発を充分に抑制
して焼成する方法としては、例えば、黒鉛、炭化珪素、
窒化アルミニウム、酸化ジルコニウム、炭化タングステ
ン、炭化チタン、酸化マグネシウム、炭化モリブデン、
モリブデン、炭化タンタエウ、タンタル、炭化ジルコニ
ウム、黒鉛−炭化珪素複合体の中から選ばれるいずれか
１種からなる外気の侵入を遮断することのできる耐熱性
の容器内に装入して焼成する方法が好ましい。According to the above method, for example, graphite, silicon carbide,
Aluminum nitride, zirconium oxide, tungsten carbide, titanium carbide, magnesium oxide, molybdenum carbide,
There is a method in which the material is placed in a heat-resistant container that can block the intrusion of outside air and is made of one selected from molybdenum, tantaeus carbide, tantalum, zirconium carbide, and graphite-silicon carbide composite. preferable.
これらの容器は前記焼成温度範囲内で溶融することがな
くその形を保持することが可能であり。These containers can maintain their shape without melting within the firing temperature range.
また前記添加物の蒸気および／または分解生成物の蒸気
の系外への漏出を抑制し、前記添加物の効果を炭化珪素
成形体のすみずみまで行きわたらせる効果がある。なか
でも、黒鉛、炭化珪素、黒鉛−炭化珪素複合体、炭化タ
ングステン、窒化アルミニウム、炭化チタン、モリブデ
ン、炭化モリブデンを有効に使用することができる。It also has the effect of suppressing leakage of the vapor of the additive and/or the vapor of the decomposition product to the outside of the system, and spreading the effects of the additive to every corner of the silicon carbide molded body. Among them, graphite, silicon carbide, graphite-silicon carbide composite, tungsten carbide, aluminum nitride, titanium carbide, molybdenum, and molybdenum carbide can be effectively used.
また本発明に係る骨材（１１）を構成する多孔質体とし
て、すなわち比較的大きな平均断面積の開放 □気
孔を有する多孔質体を得るには焼成時の昇温速度を比較
的ゆっくりとした速度で焼成すること、 。In addition, as a porous body constituting the aggregate (11) according to the present invention, in order to obtain a porous body having open pores with a relatively large average cross-sectional area, the rate of temperature increase during firing must be relatively slow. Baking at speed,.
最高温度を比較的高くすることおよび／または最高温度
での保持時間を長くすることが好ましい。It is preferable to make the maximum temperature relatively high and/or to lengthen the holding time at the maximum temperature.
この条件によれば１個々の炭化珪素の板状結晶を大きく
成長させることができ、その結果大きな気 □孔
断面積を有する多孔質体を得ることができる。Under these conditions, each plate-shaped crystal of silicon carbide can be grown to a large size, and as a result, a porous body having a large pore cross-sectional area can be obtained.
これとは逆に１本発明に係る骨材（１１）を構成す
□る多孔質体として、すなわち比較的小さな平均断面
積の開放気孔を有する多孔質体を得るには、焼成時の昇
温速度を比較的速くすること、最高温度 □を比較
的小さくすることおよび／または最高温度 ：に°
おける保持時間を短くすることが好ましい、この条件に
よれば、個々の炭化珪素の板状結晶をそ □。On the contrary, one component of the aggregate (11) according to the present invention is
In order to obtain a porous body having open pores with a relatively small average cross-sectional area, the temperature increase rate during firing must be relatively fast, the maximum temperature □ must be relatively small, and / or maximum temperature: to °
According to this condition, it is preferable to shorten the holding time in the □.
れほど成長させることがないからである。This is because they are not allowed to grow as much.
また、上記の方法によれば１７００〜２３００℃の温度
範囲で焼成することが必要である。この理由は、焼成温
度が１７００℃よりも低いと粒子の成長が不十分であり
、高い強度を有する多孔質体を得ることが困難だからで
ある。一方、２３００℃よりも高い温度になると、炭化
珪素の昇華が盛んになって発達した板状結晶が逆にやせ
細ってしまい、その結果−高い強度を持った多孔質体を
得ることが困難となるためであり、なかでも１７５０〜
２２５０℃の間で焼成することがより好適である。Further, according to the above method, it is necessary to perform firing in a temperature range of 1700 to 2300°C. The reason for this is that if the firing temperature is lower than 1700°C, the growth of particles will be insufficient and it will be difficult to obtain a porous body with high strength. On the other hand, when the temperature is higher than 2300°C, the sublimation of silicon carbide increases and the developed plate-like crystals become thinner, making it difficult to obtain a porous body with high strength. Especially from 1750~
It is more preferable to fire at a temperature between 2250°C.
次に、本発明に係る骨材（１１）を形成する場合の実施
例および比較例について説明する。Next, Examples and Comparative Examples for forming aggregate (11) according to the present invention will be described.
出発原料として使用した炭化珪素微粉末は８４．８重量
％がβ型結晶で残部が実質的に２Ｈ型結晶よりなり、
０．３１１重量％の遊離炭素、０．１７重量％の酸素、
０．０３重量％の鉄、 ０．０３重量％のアルミニウ
ムを主として含有し、０．２８μｍの平均粒径を有して
いた。前記炭化珪素微粉末１００重量部に対し、ポリビ
ニルアルコール５重量部、水３００重量部を配合し、ボ
ールミル中で５時間混合した後乾燥した。The silicon carbide fine powder used as a starting material consisted of 84.8% by weight of β-type crystals and the remainder substantially of 2H-type crystals,
0.311% by weight free carbon, 0.17% by weight oxygen,
It mainly contained 0.03% by weight of iron, 0.03% by weight of aluminum, and had an average particle size of 0.28 μm. 5 parts by weight of polyvinyl alcohol and 300 parts by weight of water were blended with 100 parts by weight of the silicon carbide fine powder, mixed in a ball mill for 5 hours, and then dried.
この乾燥混合物を適量採取し、ｌＮ粒化した後金属製押
し型を用いて５０ｋｇ／ｃｍ″の圧力で成型した。An appropriate amount of this dry mixture was collected, granulated into 1N particles, and then molded using a metal mold at a pressure of 50 kg/cm''.
この生成形体の密度は１．２ｇ／ｃｍ″、乾燥重量は２
１ｇであった。The density of this product is 1.2 g/cm'', and the dry weight is 2
It was 1g.
前記生成形体を外気を遮断することのできる黒鉛製ルツ
ボの装置内に装入し、タンマン型焼成炉を使用して１気
圧のアルゴンガス雰囲気中で焼成した。なお、前記黒鉛
製ルツボは内容積が５０ｍｆＬのものを使用した。焼成
は２．５℃／分で２２００℃まで昇温し、最高温度２２
００℃で６時間保持した。The formed body was placed in a graphite crucible that can be shut off from outside air, and fired in an argon gas atmosphere at 1 atm using a Tammann type firing furnace. The graphite crucible used had an internal volume of 50 mfL. Firing was performed at a rate of 2.5°C/min to 2200°C, with a maximum temperature of 22°C.
The temperature was maintained at 00°C for 6 hours.
得られた焼結体の重量は１９．８ｇであり、その結晶構
造は第３図の走査型電子顕微鏡写真（３５倍）に示した
ように、平均アスペクト比が１２で長軸方向の平均長さ
が３８０１Ｌｍの板状結晶が多方向に複雑に絡み合った
三次元網目構造を有しており、３〜５０のアスペクト比
を有する板状結晶の含有量は多孔置体全重量の９８％で
あった。また。The weight of the obtained sintered body was 19.8 g, and its crystal structure had an average aspect ratio of 12 and an average length in the major axis direction, as shown in the scanning electron micrograph (35x magnification) in Figure 3. The plate crystals with a diameter of 3801 Lm have a three-dimensional network structure in which they are intricately intertwined in multiple directions, and the content of plate crystals with an aspect ratio of 3 to 50 is 98% of the total weight of the porous holder. Ta. Also.
この多孔質体の気孔は直線的でない開放気孔であって、
その開放気孔率は全容積の６４％を占めており、比表面
積は１．２ｍ″／ｇであった。The pores of this porous body are non-linear open pores,
Its open porosity accounted for 64% of the total volume, and the specific surface area was 1.2 m''/g.
この焼結体の曲げ強度は１８０ ｋｇ／ｃｒｎ’と高く
、またこの多孔質体の通気特性を肉厚５ｍｍの試験片を
使用し、２０℃の空気をｉｎ／ｓｅｃの流速で通過させ
て測定したところ、その圧力損失は４８０ｍｍ水柱以下
であった。The bending strength of this sintered body is as high as 180 kg/crn', and the ventilation properties of this porous body were measured using a test piece with a wall thickness of 5 mm, by passing air at a temperature of 20°C at a flow rate of in/sec. As a result, the pressure loss was less than 480 mm water column.
庭笠１」
骨材（１１）の実施例１と同様な方法であるが、成形体
を黒鉛製のルツボに入れず、そのままアルゴン雰囲気中
で常圧焼結を行なったところ、１８．８ｇの焼結体が得
られ、その結晶構造は平均アスペクト比が１．８．長軸
方向の平均長さ３０μｍのほとんと粒状の炭化珪素から
なる構造であった。この焼結体の気孔率は全容積の６７
重量％であった ・が、曲げ強度は４ ｋｇ／ｃ
ｍ”であり著しく低いものと □なった。Niwakasa 1'' The same method as in Example 1 for aggregate (11) was used, but the molded body was not placed in a graphite crucible and was subjected to atmospheric pressure sintering in an argon atmosphere. As a result, 18.8 g of A sintered body was obtained, and its crystal structure had an average aspect ratio of 1.8. It had a structure consisting of mostly granular silicon carbide with an average length in the major axis direction of 30 μm. The porosity of this sintered body is 67% of the total volume.
% by weight, but the bending strength was 4 kg/c
m”, which was extremely low.
１１ ２ び３
骨材（１１）の実施例１と同様であるが、３０００
’ｋｇ／ｃゴ、１０ｋｇ／ｃゴの成形圧で成形し
た生成形体 ′□
をそれぞれ炭化タングステン製のルツボおよび９５％の
理論密度を有する炭化珪素製ルツボに装入して焼成した
。結果は表１に示した。11 2 and 3 Same as Example 1 of aggregate (11), but with 3000
The green bodies molded at molding pressures of 10 kg/c and 10 kg/c were charged into a tungsten carbide crucible and a silicon carbide crucible having a theoretical density of 95%, respectively, and fired. The results are shown in Table 1.
１１ ４ び ２骨材（１
１）の実施例１と同様な方法であるが、出発原料として
上記実施例１で使用した炭化珪素粉末とα型炭化珪素粉
末を、表２に示した混合比で □混合して多孔質
焼結体を製造した。なお、前記α型炭化珪素粉末は市販
のα型炭化珪素粉末（ＧＣ’＃ ３０００）を粉砕し、
さらに精製１粒度分級したちのであって、０．４重量％
の遊離炭素と０．１３重量％の酸素を含有し、平均粒径
は８．４ルｍであった。11 4 and 2 aggregate (1
The method is similar to Example 1 in 1), but the silicon carbide powder and α-type silicon carbide powder used in Example 1 above are mixed as starting materials at the mixing ratio shown in Table 2, and porous sintering is performed. A body was produced. The α-type silicon carbide powder is obtained by pulverizing a commercially available α-type silicon carbide powder (GC'#3000).
Furthermore, it has been purified and classified into particle sizes, and is 0.4% by weight.
of free carbon and 0.13% by weight of oxygen, and the average particle size was 8.4 lm.
１１ ５ び６
骨材（１１）の実施例１と同様であるが１表３に示した
如き昇温速度、最高焼成温度、および最高温度における
保持時間でもって多孔質炭化珪素焼結体を製造した。11 5 and 6 A porous silicon carbide sintered body was produced using the same method as in Example 1 for aggregate (11), but with the temperature increase rate, maximum firing temperature, and holding time at the maximum temperature as shown in Table 3. did.
出発原料として使用した炭化珪素微粉末はβ型結晶が９
４．５重量％で残部が実質的に２Ｈ型結晶よりなり、
０．３９ｆｉ量％の遊離炭素、０．１７重量％の酸１、
０．０３重量％の鉄、０．０３重量％のアルミニウムを
主として含有し、 ０．２８１Ｌｍの平均粒径を有して
いた。The silicon carbide fine powder used as a starting material has 9 β-type crystals.
4.5% by weight, the remainder substantially consisting of 2H type crystals,
0.39% by weight free carbon, 0.17% by weight acid 1,
It mainly contained 0.03% by weight of iron and 0.03% by weight of aluminum, and had an average particle size of 0.281 Lm.
前記炭化珪素微粉末１００重量部に対し、０．３重量部
の非晶質ホウ素と成形用バインダーとしてポリエチレン
グリコール１重量部、ポリアクリル酸エステル４重量部
、ベンゼン１００重量部を配合し、ボールミル中で２０
時間混合した後乾燥した。To 100 parts by weight of the silicon carbide fine powder, 0.3 parts by weight of amorphous boron, 1 part by weight of polyethylene glycol as a molding binder, 4 parts by weight of polyacrylic acid ester, and 100 parts by weight of benzene were mixed, and the mixture was placed in a ball mill. 20 in
After mixing for an hour, it was dried.
この乾燥混合物を適量配合して顆粒化した後。After blending an appropriate amount of this dry mixture and granulating it.
金ｌＩ製押し型を用いて５０ ｋｇ／ａｍ″の圧力で成
型した。この生成形体の密度は１〜２ｇ／ｃｍ″、乾燥
重量は２１ｇであった。It was molded using a gold lI pressing die at a pressure of 50 kg/am''. The density of the formed body was 1 to 2 g/cm'', and the dry weight was 21 g.
この生成形体を外気を遮断することのできる黒鉛製ルツ
ボに装入し、タンマン型焼成炉を使用して１気圧のアル
ゴンガス雰囲気中で焼成した。なお、前記黒鉛製ルツボ
は内容積が５０ｍ見のものを使用した。This formed body was placed in a graphite crucible that can be shut off from the outside air, and fired in an argon gas atmosphere at 1 atm using a Tammann type firing furnace. The graphite crucible used had an internal volume of approximately 50 m.
焼成は５℃／分で２１００℃まで昇温し、最適温度２１
００℃で４時間保持した。The temperature was increased to 2100°C at a rate of 5°C/min for firing, and the optimum temperature was 21.
It was held at 00°C for 4 hours.
得られた焼結体の結晶構造は第４図の走査型電子顕微鏡
写真（５００倍）に示したように、平均アスペクト比が
１０で長軸方向の平均長さが１３１Ｌｍの板状結晶が多
方向に複雑に絡み合った三次元網目構造を有しており、
３〜５０のアスペクト比を有する板状結晶の含有量は多
孔置体全重量の９６％であった。また、この多孔質体の
気孔は直線的でない開放気孔であり、その開放気孔率は
全容積の６１％を占めており、比表面積は３．８ｍ’／
ｇであった・
この焼結体の曲げ強度は２３７０ｋｇ／ｃｒｎ”と高く
、またこの多孔質体の通気特性を肉厚５ｍｍの試験片を
使用し、２０℃の空気をｌ ｍ１ｓｅｃの流速で通過さ
せて測定したところ、その圧力損失は７３０ｍｍ水柱以
下であった。The crystal structure of the obtained sintered body, as shown in the scanning electron micrograph (500x magnification) in Figure 4, consists of many plate-like crystals with an average aspect ratio of 10 and an average length in the major axis direction of 131 Lm. It has a three-dimensional network structure that is intricately intertwined in the direction.
The content of plate crystals having an aspect ratio of 3 to 50 was 96% of the total weight of the porous body. In addition, the pores of this porous material are non-linear open pores, and the open porosity accounts for 61% of the total volume, and the specific surface area is 3.8 m'/
The bending strength of this sintered body was as high as 2370 kg/crn, and the ventilation properties of this porous body were measured using a test piece with a wall thickness of 5 mm, through which air at 20°C was passed through at a flow rate of 1 m1sec. When measured, the pressure loss was less than 730 mm of water column.
ｔｔ ａ
骨材（１１）の実施例７と同様であるが、添加物として
非晶質ホウ素にかえてアルミニウム、ニホウ化アルミニ
ウム、炭化アルミニウム窒化アルミニウム、酸化アルミ
ニウム、炭化ホウ素、窒化ホウ素、酸化ホウ素、酸化カ
ルシウム、炭化カルシウム、クロム、ホウ化クロム、窒
化クロム、酸化クロム、鉄、炭化鉄、ホウ化ランタン、
酸化ランタン、酸化リチウム、珪素窒化珪素、炭化珪素
、チタン、酸化チタン、二酸化チタン、三酸化チタンお
よび酸化イツトリウムを使用して多孔質焼結体を製造し
た。これらの多孔質炭化珪素焼結体は、いずれも板状結
晶が良く発達した結晶構造を有しており、曲げ強度、通
気特性等に著しく優れていた。tt a Same as Example 7 of aggregate (11), but instead of amorphous boron, aluminum, aluminum diboride, aluminum carbide, aluminum nitride, aluminum oxide, boron carbide, boron nitride, boron oxide, Calcium oxide, calcium carbide, chromium, chromium boride, chromium nitride, chromium oxide, iron, iron carbide, lanthanum boride,
A porous sintered body was manufactured using lanthanum oxide, lithium oxide, silicon nitride, silicon carbide, titanium, titanium oxide, titanium dioxide, titanium trioxide, and yttrium oxide. These porous silicon carbide sintered bodies all had a crystal structure in which plate crystals were well developed, and were extremely excellent in bending strength, air permeability, etc.
以上に述べてきた方法によれば、雰囲気の制御により、
骨材（１１）に適したアスペクト比、気孔径等が均一に
そろった多孔質炭化珪素焼結体を製造することができた
。According to the method described above, by controlling the atmosphere,
It was possible to produce a porous silicon carbide sintered body with uniform aspect ratio, pore diameter, etc. suitable for aggregate (11).
次に、この骨材（１１）に酸化物被Ｓ層（１３）を形成
する場合の実施例について説明する。この骨材（１１）
を構成する三次元網目構造の炭化珪素焼結体の表面に触
媒を担持し得るように形成した酸化物被膜層（１３）を
形成する方法としては１例えば所望の酸化物を形成する
ための元素を含有する溶液中に前記多孔質の炭化珪素焼
結体を浸漬した後焼成する方法を適用することができる
。前記所望の酸化物をするための元素を含有する溶液と
しては１例えば金属アルコキシド、水酸化物、塩などの
水溶液を使用することができる。Next, an example in which an oxide S layer (13) is formed on this aggregate (11) will be described. This aggregate (11)
As a method for forming an oxide coating layer (13) formed to be able to support a catalyst on the surface of a silicon carbide sintered body having a three-dimensional network structure constituting the A method can be applied in which the porous silicon carbide sintered body is immersed in a solution containing and then fired. As the solution containing the elements for forming the desired oxide, for example, an aqueous solution of metal alkoxide, hydroxide, salt, etc. can be used.
特に、酸化珪素やアルミナについてはシリカゾルやアル
ミナゾルを使用することが有利である。In particular, for silicon oxide and alumina, it is advantageous to use silica sol or alumina sol.
次に、上述した骨材（！１）に酸化物被膜層（１３）を
形成して触媒担体（１０）としたものに、゛実際に触媒
を担持した実施例について説明する。Next, an example in which a catalyst was actually supported on the catalyst carrier (10) formed by forming an oxide film layer (13) on the above-mentioned aggregate (!1) will be described.
支ム１」
上述したようにして骨材（１１）の実施例１と略同様の
条件であるが、押出成形によって得られたハニカム形状
の多孔質炭化珪素焼結体である骨材（１１）に１０％の
シリカゾルを真空中で含浸、乾燥した後、１４００℃で
５０％の水蒸気気流中で１０時間保持したところ、 １
３．５％の重量増加となった。Strut 1'' The conditions were substantially the same as in Example 1 for the aggregate (11) as described above, but the aggregate (11) was a honeycomb-shaped porous silicon carbide sintered body obtained by extrusion molding. was impregnated with 10% silica sol in a vacuum, dried, and then held at 1400°C in a 50% steam stream for 10 hours. 1
The weight increased by 3.5%.
次いで、塩化白金酸の水溶液に浸漬して乾燥し、水素中
で５００℃、１時間焼成することにより。Then, it was immersed in an aqueous solution of chloroplatinic acid, dried, and calcined in hydrogen at 500° C. for 1 hour.
ハニカム体積の１１に対し１．３ｇの割合で白金触媒を
担持した。これを排気量３皇のディーゼル機関の消音マ
フラーの後部に取付けて、５００時間運転し、その前後
のＣｏ、ＨＣ，Ｎｏ、の浄化率と微粒子状炭素の除去率
を調べた。その結果を表４に示す。The platinum catalyst was supported at a ratio of 1.3 g to 11 of the honeycomb volume. This was attached to the rear of the muffler of a diesel engine with a displacement of 3,000 liters, and the engine was operated for 500 hours, and the purification rate of Co, HC, and No. and the removal rate of particulate carbon were investigated before and after the operation. The results are shown in Table 4.
表４
運転条件 回 転 数 ３０００ｒｐ−空気
過剰率 １．３
触媒入口温度 ３８０℃
触媒出口温度 ８９０℃
この表４に示す如＜、Ｃｏ、ＨＣ，ＮＯｘ及び微粒子状
炭素が高い効率で除去された。一方、触媒の出口温度が
９００℃の高温状態になっても、へ二カムおよび触媒自
体に何ら変化がなく、極めて触媒効果の高いハニカム触
媒体であることがわかった。Table 4 Operating conditions Rotation speed 3000 rpm - Excess air ratio 1.3 Catalyst inlet temperature 380°C Catalyst outlet temperature 890°C As shown in Table 4, Co, HC, NOx and particulate carbon were removed with high efficiency. On the other hand, even when the outlet temperature of the catalyst reached a high temperature of 900° C., there was no change in the henicum and the catalyst itself, indicating that the honeycomb catalyst body had an extremely high catalytic effect.
丈ＪＪＬヱ
上記の実施例１と同様に形成された多孔質炭化珪素焼結
体からなるハニカム構造体である骨材（１１）の表面に
１表５に示した酸化物を被覆して酸化物被膜層（１３）
を形成し、その後に表５に示した触媒成分を担持させた
。なお、骨材（１１）の表面に被覆した酸化物のうち、
ＳｔＯ，以外の酸化物はまずＳｉＯユ被膜を実施例１と
同様に形成した後、その表５
上に約１．５μｍまでの厚さの酸化物被覆層（１３）が
形成されるように含浸濃度、焼き付は温度を適宜コント
ロールした。The surface of the aggregate (11), which is a honeycomb structure made of porous silicon carbide sintered body formed in the same manner as in Example 1 above, is coated with the oxides shown in Table 1 to form an oxide. Coating layer (13)
was formed, and then the catalyst components shown in Table 5 were supported. In addition, among the oxides coated on the surface of the aggregate (11),
For oxides other than StO, a SiO coating was first formed in the same manner as in Example 1, and then impregnated so that an oxide coating layer (13) with a thickness of up to about 1.5 μm was formed on the SiO coating. Temperature was appropriately controlled for density and baking.
そして、表６に示した成分よりなるボイラー排気ガス中
の窒素酸化物の脱硝および脱硫試験を行ない表５にまと
めた０表５に示した結果は、初期およびｔｏｏｏ時間経
過後のものである。。A denitrification and desulfurization test was conducted for nitrogen oxides in boiler exhaust gas containing the components shown in Table 6, and the results are summarized in Table 5. The results shown in Table 5 are initial and after too many hours. .
（以下余白）
表６
上記の実施例１及び２と同様に、コージェライト買上に
触媒を担持させ、同じ条件下で触媒体の特性を調べたと
ころ次の表７のような結果となり表７
単に従来のものと同じハニカム構造体に排気ガスを流し
ても充分な微粒子状炭素の除去率を得られなかった。(Leaving space below) Table 6 Similar to Examples 1 and 2 above, a catalyst was supported on cordierite and the characteristics of the catalyst body were investigated under the same conditions, resulting in the results shown in Table 7 below. Even when exhaust gas was passed through the same honeycomb structure as the conventional one, a sufficient removal rate of particulate carbon could not be obtained.
そこで、同じハニカム構造体の通路の一方の端面におい
て、その通路を１個おきに閉鎖し、他方の端面において
は上記閉塞した通路以外の通路をコージェライト緻密質
体で閉鎖したハニカム構造体としたところ、圧力損失は
１１０ｍｍ水柱となった・
このハニカム構造体を上記と同様に排気ガスの除去効率
（％）を測定したところ１次の表８のようになった。Therefore, on one end face of the same honeycomb structure, every other passage was closed, and on the other end face, the passages other than the closed passages were closed with a cordierite dense body. However, the pressure loss was 110 mm water column. When the exhaust gas removal efficiency (%) of this honeycomb structure was measured in the same manner as above, the results were as shown in Table 8 below.
表８
結果が示すように、１００時間の運転では除去効率が若
干向上したが、２００時間では除去効率が著しく低下し
た。また、当該ハニカム構造体は一部濾過した微粒子状
炭素が酸化されることなく通路を閉塞し、濾過機能が阻
害された部分があり、他方酸化時の反応熱によりコージ
ェライト質が一部溶解損失していた。Table 8 As shown in the results, the removal efficiency slightly improved after 100 hours of operation, but the removal efficiency significantly decreased after 200 hours. In addition, in the honeycomb structure, there were some parts where the filtered particulate carbon blocked the passage without being oxidized and the filtration function was inhibited, and on the other hand, some cordierite was dissolved and lost due to the reaction heat during oxidation. Was.
（発明の作用及び効果）
以上のように構成した本発明に係る触媒担体（１０）に
あっては、次のような作用及び効果がある。(Actions and Effects of the Invention) The catalyst carrier (10) according to the present invention configured as described above has the following actions and effects.
すなわち、当該触媒担体（１０）の骨１ｉＩ（１１）は
、主として炭化珪素よりなる焼結体から構成され、平均
アスペクト比が３〜５０であり、かつ長軸方向の平均長
さが０．１〜１１０００１Ｌの炭化珪素質板状結晶とな
り、しかも平均断面積が０．０１〜２５００００ ｕ−
ゴである三次元網目構造の多孔質体となっている。That is, the bones 1iI (11) of the catalyst carrier (10) are mainly composed of a sintered body made of silicon carbide, have an average aspect ratio of 3 to 50, and have an average length in the major axis direction of 0.1. ~110001L silicon carbide plate crystals with an average cross-sectional area of 0.01~250000 u-
It is a porous body with a three-dimensional network structure.
これにより、当該骨材（！１）は、第１図に示した触媒
担体（１０）の各通気孔（１２）以外においても反応流
体の通過を充分許容あるいは可能とするだけでなく、そ
の前後における反応流体の圧力損失を極力少なくするも
のである。また、骨材（１１）が炭化珪素を主体とした
焼結体であることから、その耐熱性は優れたものとなっ
ている０以上のことは、当該触媒担体（１０）が第１図
に示したような所謂ハニカム構造体とした場合は勿論の
こと１例えば当該骨材（１１）を板状に形成した場合に
ついても言えることである。As a result, the aggregate (!1) not only sufficiently allows or allows the reaction fluid to pass through other than the vent holes (12) of the catalyst carrier (10) shown in FIG. This is to reduce the pressure loss of the reaction fluid as much as possible. In addition, since the aggregate (11) is a sintered body mainly composed of silicon carbide, its heat resistance is excellent. This applies not only to the so-called honeycomb structure as shown, but also to the case where, for example, the aggregate (11) is formed into a plate shape.
また、この骨材（１１）に酸化物被膜層（１３）を形成
した場合にあっては、この酸化物被膜層（１３）の層が
極めて薄いものであるから、骨材（１１）の三次元網目
構造部分において目詰りを起すようなことはない、そし
て、この酸化物波ＩＩ ７！（１３）によって、骨材（
１１）に対する触媒の担持をしやすくしているのである
。In addition, in the case where the oxide film layer (13) is formed on the aggregate (11), since the oxide film layer (13) is extremely thin, the tertiary layer of the aggregate (11) There is no clogging in the original network structure, and this oxide wave II 7! (13), aggregate (
11) makes it easier to support the catalyst.
さらに、この骨材（１１）は比較的熱伝導性の良好でな
い酸化物被膜層（１３）を形成しても、極めて熱熱伝導
性の良好な炭化珪素焼結体により骨材（１１）が形成さ
れているため、反応温度を均一化することができるもの
である。すなわち、炭化珪素焼結体からなる骨材（１１
）の上に酸化物被膜層（１３）を被 ゛覆させる
と、発熱反応によって温度が高くなった場合、第２図に
示したように、骨材（１１）及び酸化物被膜層（１３）
の熱膨張率の差によって酸化物被膜層（１３）が割れる
。すると、骨材（１１）を構成している炭化珪素焼結体
自身が反応流体に直接曝されることになる。これにより
、骨材（１１）内に熱が蓄積されていたとしても、この
骨材（１１）の付近を流れる流体によって熱が奪われて
放散され、骨材（１１）すなわち触媒担体（１Ｇ）の反
応温度を均一化するのである。Furthermore, even if this aggregate (11) forms an oxide film layer (13) with relatively poor thermal conductivity, the aggregate (11) is made of silicon carbide sintered body with extremely good thermal conductivity. Because of this structure, the reaction temperature can be made uniform. That is, aggregate (11
) When the oxide film layer (13) is coated on top of the aggregate (11) and the oxide film layer (13), when the temperature increases due to an exothermic reaction, the aggregate (11) and the oxide film layer (13)
The oxide coating layer (13) cracks due to the difference in the coefficient of thermal expansion. Then, the silicon carbide sintered body constituting the aggregate (11) is directly exposed to the reaction fluid. As a result, even if heat is accumulated in the aggregate (11), the heat is removed and dissipated by the fluid flowing near the aggregate (11), and the aggregate (11), that is, the catalyst carrier (1G) This makes the reaction temperature uniform.
従って、以上のことを総合すれば１本発明に係る触媒担
体（ｌＯ）にあっては、炭化珪素焼結体によって構成す
ることにより充分な耐熱性を備え、これによって発熱反
応を伴なう化学反応に使用するのに適したものとするこ
とができる。また、当該触媒担体（ｌＯ）を構成する骨
材（１１）自体が三次元網目構造を有する多孔質体であ
ることから１反応物質の触媒に対する接触障害を起すこ
とがなく、必要十分な反応速度が得られる触媒担体（ｌ
Ｏ）を提供することができるのである。Therefore, taking all the above into account, the catalyst carrier (1O) according to the present invention has sufficient heat resistance by being composed of a silicon carbide sintered body, and is thereby able to withstand chemical reactions involving exothermic reactions. It can be anything suitable for use in the reaction. In addition, since the aggregate (11) constituting the catalyst carrier (1O) itself is a porous material with a three-dimensional network structure, it does not cause contact failure of one reactant to the catalyst, and the necessary and sufficient reaction rate is maintained. The catalyst support (l
O) can be provided.
第１図は本発明に係る触媒担体の一実施例を示す斜視図
、第２図は第１図の■−■線に沿って見た部分拡大断面
図、第３図は骨材の実施例１に記載の焼結体の走査型電
子顕微鏡写真（３５倍）、第４図は実施例７に記載の焼
結体の走査型電子顕微鏡写真（５００倍）、第５図は従
来法による炭化珪素多孔質焼結体の構造を示す模式図、
第６図はスケルトン構造を有する多孔質体の構造を示す
模式図である。
符 号 の 説 明
１Ｇ・・・触媒担体、１１・・・骨材、１２・・・通気
孔、 １３・・・酸化物被膜層。
ｉｍ
第２図
第５図
第６図Fig. 1 is a perspective view showing one embodiment of the catalyst carrier according to the present invention, Fig. 2 is a partially enlarged sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is an example of the aggregate. A scanning electron micrograph (35x) of the sintered body described in Example 1, FIG. 4 is a scanning electron micrograph (500x) of the sintered body described in Example 7, and FIG. 5 is a scanning electron micrograph (500x) of the sintered body described in Example 7. Schematic diagram showing the structure of a silicon porous sintered body,
FIG. 6 is a schematic diagram showing the structure of a porous body having a skeleton structure. Explanation of symbols 1G... Catalyst carrier, 11... Aggregate, 12... Vent hole, 13... Oxide coating layer. im Figure 2 Figure 5 Figure 6
Claims (1)
アスペクト比が３〜５０であり、かつ長軸方向の平均長
さが０．１〜１０００μｍの炭化珪素質板状結晶から構
成されてなる三次元網目構造を有し、この網目構造の開
放気孔の平均断面積が０．０１〜２５００００μｍ＾２
である多孔質の炭化珪素焼結体からなる骨材と、 この骨材を構成する三次元網目構造の炭化珪素焼結体の
表面に触媒を担持し得るように形成した酸化物被膜層と により構成したことを特徴とする多孔質炭化珪素焼結体
からなる触媒担体。 ２）、前記三次元網目構造の開放気孔率は焼結体の全容
積に対し２０〜９５容積％であることを特徴とする特許
請求の範囲第１項に記載の多孔質炭化珪素焼結体からな
る触媒担体。 ３）、前記多孔質炭化珪素焼結体１００重量部のうち３
〜５０のアスペクト比を有する板状結晶は少なくとも２
０重量部であることを特徴とする特許請求の範囲第１項
〜第２項のいずれかに記載の多孔質炭化珪素焼結体から
なる触媒担体。 ４）、前記骨材はハニカム構造となっていることを特徴
とする特許請求の範囲第１項〜第３項のいずれかに記載
の多孔質炭化珪素焼結体からなる触媒担体。 ５）、前記焼結体の比表面積は少なくとも０．０５ｍ＾
２／ｇであることを特徴とする特許請求の範囲第１項〜
第４項のいずれかに記載の多孔質炭化珪素焼結体からな
る触媒担体。[Scope of Claims] 1) A silicon carbide plate, which is a sintered body mainly made of silicon carbide, and has an average aspect ratio of 3 to 50 and an average length in the major axis direction of 0.1 to 1000 μm. It has a three-dimensional network structure composed of shaped crystals, and the average cross-sectional area of the open pores of this network structure is 0.01 to 250,000 μm^2
An aggregate made of a porous silicon carbide sintered body, and an oxide film layer formed to support a catalyst on the surface of the three-dimensional network structure silicon carbide sintered body constituting this aggregate. A catalyst carrier made of a porous silicon carbide sintered body, characterized in that: 2) The porous silicon carbide sintered body according to claim 1, wherein the open porosity of the three-dimensional network structure is 20 to 95% by volume based on the total volume of the sintered body. A catalyst carrier consisting of. 3), 3 out of 100 parts by weight of the porous silicon carbide sintered body
Plate crystals with an aspect ratio of ~50 are at least 2
A catalyst carrier made of a porous silicon carbide sintered body according to any one of claims 1 to 2, characterized in that the amount is 0 parts by weight. 4) A catalyst carrier made of a porous silicon carbide sintered body according to any one of claims 1 to 3, wherein the aggregate has a honeycomb structure. 5) The specific surface area of the sintered body is at least 0.05 m^
2/g.
A catalyst carrier comprising the porous silicon carbide sintered body according to any one of Item 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60102298A JPH0615044B2 (en) | 1985-05-14 | 1985-05-14 | Catalyst carrier composed of porous silicon carbide sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60102298A JPH0615044B2 (en) | 1985-05-14 | 1985-05-14 | Catalyst carrier composed of porous silicon carbide sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61259763A true JPS61259763A (en) | 1986-11-18 |
| JPH0615044B2 JPH0615044B2 (en) | 1994-03-02 |
Family
ID=14323707
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60102298A Expired - Fee Related JPH0615044B2 (en) | 1985-05-14 | 1985-05-14 | Catalyst carrier composed of porous silicon carbide sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0615044B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5497620A (en) * | 1988-04-08 | 1996-03-12 | Stobbe; Per | Method of filtering particles from a flue gas, a flue gas filter means and a vehicle |
| JP4610135B2 (en) * | 2001-08-21 | 2011-01-12 | 盛和工業株式会社 | Photocatalyst carrier and method for producing porous substrate |
| CN107266078A (en) * | 2016-03-31 | 2017-10-20 | 日本碍子株式会社 | Thermal storage member |
-
1985
- 1985-05-14 JP JP60102298A patent/JPH0615044B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5497620A (en) * | 1988-04-08 | 1996-03-12 | Stobbe; Per | Method of filtering particles from a flue gas, a flue gas filter means and a vehicle |
| JP4610135B2 (en) * | 2001-08-21 | 2011-01-12 | 盛和工業株式会社 | Photocatalyst carrier and method for producing porous substrate |
| CN107266078A (en) * | 2016-03-31 | 2017-10-20 | 日本碍子株式会社 | Thermal storage member |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0615044B2 (en) | 1994-03-02 |
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