KR890008059A - 다공성의 멤브레인 및 그 제조방법 - Google Patents

다공성의 멤브레인 및 그 제조방법 Download PDF

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KR890008059A
KR890008059A KR1019880014344A KR880014344A KR890008059A KR 890008059 A KR890008059 A KR 890008059A KR 1019880014344 A KR1019880014344 A KR 1019880014344A KR 880014344 A KR880014344 A KR 880014344A KR 890008059 A KR890008059 A KR 890008059A
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polymer
metal oxide
silica
nitrogen
dispersion
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KR1019880014344A
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케이.제인 무케시
케이.나드카르니 사다시브
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원본미기재
알칸 인토내셔날 리미티드
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Publication of KR890008059A publication Critical patent/KR890008059A/ko

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D67/00Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0039Inorganic membrane manufacture
    • B01D67/0067Inorganic membrane manufacture by carbonisation or pyrolysis
    • AHUMAN NECESSITIES
    • A01AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01BSOIL WORKING IN AGRICULTURE OR FORESTRY; PARTS, DETAILS, OR ACCESSORIES OF AGRICULTURAL MACHINES OR IMPLEMENTS, IN GENERAL
    • A01B1/00Hand tools
    • A01B1/02Spades; Shovels
    • A01B1/026Spades; Shovels with auxiliary handles for facilitating lifting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D67/00Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0039Inorganic membrane manufacture
    • B01D67/0041Inorganic membrane manufacture by agglomeration of particles in the dry state
    • B01D67/00411Inorganic membrane manufacture by agglomeration of particles in the dry state by sintering
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D71/00Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/02Inorganic material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/50Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/58Fabrics or filaments
    • B01J35/59Membranes
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/0022Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/06Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2323/00Details relating to membrane preparation
    • B01D2323/12Specific ratios of components used
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00793Uses not provided for elsewhere in C04B2111/00 as filters or diaphragms
    • C04B2111/00801Membranes; Diaphragms
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/0081Uses not provided for elsewhere in C04B2111/00 as catalysts or catalyst carriers

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Structural Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Dispersion Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Soil Sciences (AREA)
  • Environmental Sciences (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Ceramic Products (AREA)

Abstract

내용 없음

Description

다공성의 멤브레인 및 그 제조방법
본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음
제 1 도는 소결된 알루미나 튜브의 외부표면을 80배로 확대한 현미경 사진이다
제 2 도는 소결된 알루미나 튜브의 외부표면을 1000배로 확대한 현미경 사진이다
제 3 도는 상기 알루미나 튜브의 내부표면을 65배 확대한 사진이다
제 4 도는 제 1 도의 튜브벽의 단면을 400배로 확대한 현미경 사진이다

Claims (14)

  1. 사용된 실리카 또는 금속 산화물의 양이 그 다음의 가열단계에서 폴리머로부터 유도된 탄소와 반응하도록 된 과량으로 포함된, 금속 산화물, 실리카 및 혼합물로 그성된 그룹으로부터 선택된 물질의 분말을 유기 폴리머에 분산시키고; 그 분산물을 형성하여 원하는 얇은 형태로 만들고; 비산화성 분위기에서 가열함으로써 폴리머를 탄화시키고; 질소를 전혀 포함하지 않거나 또는 비다공성의 생성물이 형성되는 양보다 적은양의 질소를 포함한 비산화성 분위기에서 상기 생성물을 탄소가 산화물과 반응하는 한편 남은 미반응 산화물 입자가 같이 소결되는 온도로 가열하는 것으로 구성된 것을 특징으로 하는 실리카 또는 금속 산화물로 제조된 다공성의 멤브레인을 제조하는 방법
  2. 제 1 항에 있어서, 금속 산화물이 알루미나, 티타니아 지르코니아, 이트리아 또는 텅스텐 산화물로 구성된 그룹으로부터 선택된 것을 특징으로 하는 방법
  3. 제 1 항에 있어서, 폴리머가 포리아크릴로 니트릴 및 그코폴리머 및 터포리머, 셀풀로오즈 및 그 유도체, 포리비닐알콜 및 그코폴리머 및 터폴리머, 폴리에틸렌 글리콜, 폴리아릴에테르, 폴리아세나프틸렌 및 폴리악세틸렌인 것을 특징으로 하는 방법
  4. 제 1 항에 있어서, 유기 폴리머에서 분말의 분산이 적합한 용매속에 있는 폴리머 용액에 실린카 또는 금속 산화물을 첨가함으로서 형성되고 이어서 용매를 제거하는 것을 특징으로 하는 방법
  5. 제 4 항에 있어서, 용매가 이어서 용매 건조에 의해서 용액으로부터 제거되는 것을 특징으로하는 방법
  6. 제 1 항에서 3항 중 어느 한 항에 있어서, 탄화단계동안에 폴리머로부터 유도되는 탄소에 대한 실리카 또는 금속 산화물의 비가 몰비로 1:1보다 큰 것을 특징으로 하는 방법
  7. 제 1 항에서 3항중 어느 한 항에 있어서, 상기 가열단계가 10-20부피%의 질소를 포함하는 분위기에서 수행되는 것을 특징으로하는 방법
  8. 제 1 항에서 3항중 어느 한 항에 있어서, 상기 가열단계가 우선 질소를 포함하지 않은 분위기에서 수행되고 이어서 추가의 다공성의 형성을 방지하기 위하여 질소를 주입 하는 것을 특징으로 하는 방법
  9. 제 1 항에서 3항중 어느 한 항에 있어서, 금속 산화물이 알루미나 인 것을 특징으로 하는 방법
  10. 제 1 항에서 3항 중 어느 한 항에 있어서, 상기 물질의 입자가범위의 크기를 가진 것을 특징으로 하는 벙법
  11. 제 1 항에서 3항중 어느 한 항에 있어서, 상기 물질의 입자가보다 작은 크기를 가진 것을 특징으로 하는 방법
  12. 제 1 항에서 3항중 어느 한 항에 있어서, 분산물이 5mm이하의 두께를 가진 형태로 성형되는 것을 특징으로 하는 방법
  13. 제 1 항에서 3 항중 어느 한 항에 있어서, 분산물이 시이트, 판 및 튜브로 구성된 그룹으로부터 선택된 얇은 형태로 성형되는 것을 특징으로 하는 방법
  14. 제 1 항에서 3항중 어느 한 항에 따른 방법에 의해 제조되는 실리카 또는 내화성의 금속 산화물로 제조된 다공성의 멤브레인
    ※ 참고사항 : 최초출원 내용에 의하여 공개하는 것임.
KR1019880014344A 1987-11-03 1988-11-01 다공성의 멤브레인 및 그 제조방법 KR890008059A (ko)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA000550959A CA1269404A (en) 1987-11-03 1987-11-03 Porous membrane of sinterable refractory metal oxides or silica
CA550959 1987-11-03

Publications (1)

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KR890008059A true KR890008059A (ko) 1989-07-08

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US (1) US4973435A (ko)
EP (1) EP0315453A3 (ko)
JP (1) JPH01261285A (ko)
KR (1) KR890008059A (ko)
CN (1) CN1032932A (ko)
AU (1) AU2458688A (ko)
BR (1) BR8805659A (ko)
CA (1) CA1269404A (ko)
DK (1) DK610188A (ko)
NO (1) NO884890L (ko)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101487107B1 (ko) * 2013-12-24 2015-01-28 오씨아이 주식회사 글리콜 에테르 탈수용 유-무기 복합막을 이용한 투과증발 시스템
KR20210039070A (ko) * 2019-10-01 2021-04-09 한국화학연구원 입도제어 가능한 고속 순간 혼화방식 액상폴리머 용해장치

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2766029B2 (ja) * 1990-03-12 1998-06-18 日本碍子株式会社 セラミックグリーンシート材及び電気化学的素子並びにその製造方法
FR2665087B1 (fr) * 1990-07-24 1992-10-09 Lorraine Carbone Procede de fabrication d'une membrane minerale ultra-mince et asymetrique.
FR2684092B1 (fr) * 1991-11-21 1994-03-04 Pechiney Recherche Procede de preparation de carbures metalliques a grande surface specifique a partir de mousses de carbone activees.
CN1048236C (zh) * 1992-08-21 2000-01-12 胡小弟 耐高温陶瓷过滤器的制造方法
US5770275A (en) * 1996-08-23 1998-06-23 Raman; Narayan K. Molecular sieving silica membrane fabrication process
US5935646A (en) * 1996-08-23 1999-08-10 Gas Research Institute Molecular sieving silica membrane fabrication process
US6087024A (en) * 1996-12-17 2000-07-11 Whinnery; Leroy Louis Method for forming porous sintered bodies with controlled pore structure
AT406699B (de) 1997-10-15 2000-07-25 Lisec Peter Verfahren und vorrichtung zum füllen von randfugen von isolierglasscheiben
JP2000288325A (ja) * 1999-02-01 2000-10-17 Ngk Insulators Ltd セラミック多孔質膜を分離膜とするフィルタの製造方法
DE10024561A1 (de) * 2000-05-18 2001-11-22 Basf Ag Verfahren zur Herstellung von porösen anorganischen Festkörpern aus einer wässrigen Kompositpartikeldispersion
KR100469066B1 (ko) * 2003-04-14 2005-02-02 에스케이 주식회사 디젤차량 입자상 물질 제거용 필터 및 이의 제조방법
US6998009B2 (en) 2003-06-10 2006-02-14 Ut-Battelle, Llc Filter and method of fabricating
DE102005023255A1 (de) * 2005-05-20 2006-11-30 Areva Np Gmbh Sammelleitung zur Leckageüberwachung und Leckageortung
KR101310883B1 (ko) * 2006-03-29 2013-09-25 삼성에스디아이 주식회사 다공성 금속 산화물 및 그 제조방법
US7740816B1 (en) * 2008-02-06 2010-06-22 Vapor Point, LLC Method for treating gases to be scrubbed
CN103874874B (zh) * 2011-10-14 2016-11-09 阿塞里克股份有限公司 真空隔热板

Family Cites Families (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8178C (ko) * 1919-07-10
US2799912A (en) * 1950-12-18 1957-07-23 Greger Herbert Hans Processes for forming high temperature ceramic articles
US2797201A (en) * 1953-05-11 1957-06-25 Standard Oil Co Process of producing hollow particles and resulting product
US2806509A (en) * 1956-06-11 1957-09-17 Goodyear Aircraft Corp Sandwich structures
US2918923A (en) * 1956-07-13 1959-12-29 American Mach & Foundry Cigarette machine
LU39124A1 (ko) * 1959-09-03
US3615972A (en) * 1967-04-28 1971-10-26 Dow Chemical Co Expansible thermoplastic polymer particles containing volatile fluid foaming agent and method of foaming the same
US3436174A (en) * 1967-10-18 1969-04-01 Norton Co Synthetic mordenite and preparation thereof
BE787964A (fr) * 1971-08-24 1973-02-26 Montedison Spa Procede de preparation de membranes ou barrieres composites poreuses pour installations de diffusion gazeuse
US3873475A (en) * 1971-09-01 1975-03-25 Minnesota Mining & Mfg Composition for filling, patching and the like
US3792136A (en) * 1971-11-02 1974-02-12 Atomic Energy Commission Method for preparing hollow metal oxide microsphere
US3914360A (en) * 1973-04-23 1975-10-21 Dow Chemical Co Expansion of expandable synthetic resinous microspheres
US4104345A (en) * 1975-06-23 1978-08-01 International Business Machines Corporation Ceramic dielectrics
CH604826A5 (en) * 1975-12-29 1978-09-15 Commissariat Energie Atomique Filter of inorganic material prepn.
GB1535471A (en) * 1976-02-26 1978-12-13 Toyo Boseki Process for preparation of a metal carbide-containing moulded product
US4191721A (en) * 1977-10-06 1980-03-04 General Electric Company Making ceramic articles having a high degree of porosity and crushability characteristics
JPS5492629A (en) * 1977-12-28 1979-07-23 Yashima Kagaku Kogyo Kk Herbicide for rice field
US4256676A (en) * 1978-11-22 1981-03-17 Kovach Julius L Process for preparing porous metal oxide beads
JPS5927743B2 (ja) * 1979-02-28 1984-07-07 旭硝子株式会社 セラミック紛未の成形品の処理方法
JPS55159946A (en) * 1979-05-31 1980-12-12 Matsushita Electric Works Ltd Forming method for heat-insulating material
US4247500A (en) * 1979-12-07 1981-01-27 Bell Telephone Laboratories, Incorporated Fabrication of ferrite material
US4284612A (en) * 1980-01-28 1981-08-18 Great Lakes Carbon Corporation Preparation of SiC whiskers
US4327192A (en) * 1980-10-06 1982-04-27 The United States Of America As Represented By The United States Department Of Energy Method of fabricating nested shells and resulting product
DE3105556A1 (de) * 1981-02-16 1982-09-02 Henkel KGaA, 4000 Düsseldorf "verbessertes verfahren zur herstellung von xanthomonas-biopolymeren"
FR2502508B1 (fr) * 1981-03-30 1985-10-25 Geceral Grpt Etu Ceramiques Al Structure de filtration, procede de realisation de telles structures et dispositif d'ultrafiltration en comportant
JPS5849488A (ja) * 1981-09-18 1983-03-23 Kao Corp 消臭・脱臭剤組成物
EP0111008B1 (en) * 1982-06-01 1989-12-27 MITSUI TOATSU CHEMICALS, Inc. Process for manufacturing metal carbides and their precursors
JPS6052120B2 (ja) * 1982-06-04 1985-11-18 タテホ化学工業株式会社 炭化珪素の製造方法
DD242325A3 (de) * 1983-05-27 1987-01-28 Reiner Kinder Verfahren zur herstellung hochporoeser mineralischer koerper mit polyformer struktur
US4536379A (en) * 1983-06-02 1985-08-20 Graphite Sales, Inc. Production of silicon carbide
JPS60176910A (ja) * 1984-02-22 1985-09-11 Tokuyama Soda Co Ltd 窒化アルミニウム粉末の製造方法
JPS60177198A (ja) * 1984-02-22 1985-09-11 Nippon Sheet Glass Co Ltd 薄膜状Al↓2O↓3多孔質体の製造方法
FR2565964A1 (fr) * 1984-06-13 1985-12-20 Lafarge Refractaires Nouveaux refractaires a haute teneur en alumine et leur procede d'obtention
JPS6171804A (ja) * 1984-09-17 1986-04-12 Toyo Soda Mfg Co Ltd 多孔性酸化アルミニウム膜
DE3572155D1 (en) * 1984-09-28 1989-09-14 Toshiba Kk Process for production of readily sinterable aluminum nitride powder
JPS61155260A (ja) * 1984-12-27 1986-07-14 呉羽化学工業株式会社 炭素材同士を接合した炭素製品の製造方法
JPS61201606A (ja) * 1985-03-05 1986-09-06 Chuzo Kato 無機有機高分子複合体より窒化物および炭化物の製造方法
JPS62129144A (ja) * 1985-11-28 1987-06-11 Kansai Coke & Chem Co Ltd 多孔性複合構造物およびその製造法
JPS62167209A (ja) * 1986-01-17 1987-07-23 Natl Inst For Res In Inorg Mater α−サイアロン質粉末及びその製造法
US4784839A (en) * 1986-04-03 1988-11-15 Atochem Method of making metal carbide and nitride powders
KR910001300B1 (ko) * 1986-11-28 1991-03-02 가와사키세이데쓰 가부시키가이샤 질화 알루미늄 분말의 제조방법
US4686244A (en) * 1986-12-17 1987-08-11 Dow Corning Corporation Intumescent foamable compositions
US4857246A (en) * 1988-01-21 1989-08-15 E. I. Du Pont De Nemours And Company Aluminum nitride articles by carbothermal nitridation

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101487107B1 (ko) * 2013-12-24 2015-01-28 오씨아이 주식회사 글리콜 에테르 탈수용 유-무기 복합막을 이용한 투과증발 시스템
KR20210039070A (ko) * 2019-10-01 2021-04-09 한국화학연구원 입도제어 가능한 고속 순간 혼화방식 액상폴리머 용해장치

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AU2458688A (en) 1989-05-04
DK610188D0 (da) 1988-11-02
CN1032932A (zh) 1989-05-17
NO884890L (no) 1989-05-05
JPH01261285A (ja) 1989-10-18
US4973435A (en) 1990-11-27
NO884890D0 (no) 1988-11-02
EP0315453A3 (en) 1991-01-30
CA1269404A (en) 1990-05-22
DK610188A (da) 1989-05-04
EP0315453A2 (en) 1989-05-10

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