EP1301434A2 - Nanoscale corundum powders, sintered compacts produced from these powders and method for producing the same - Google Patents
Nanoscale corundum powders, sintered compacts produced from these powders and method for producing the sameInfo
- Publication number
- EP1301434A2 EP1301434A2 EP01960526A EP01960526A EP1301434A2 EP 1301434 A2 EP1301434 A2 EP 1301434A2 EP 01960526 A EP01960526 A EP 01960526A EP 01960526 A EP01960526 A EP 01960526A EP 1301434 A2 EP1301434 A2 EP 1301434A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- corundum
- precursor
- aluminum
- temperatures
- powders
- 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.)
- Withdrawn
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Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/34—Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
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- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/44—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water
- C01F7/441—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water by calcination
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
- C04B35/111—Fine ceramics
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/62645—Thermal treatment of powders or mixtures thereof other than sintering
- C04B35/62675—Thermal treatment of powders or mixtures thereof other than sintering characterised by the treatment temperature
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/6269—Curing of mixtures
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- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
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- C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
- C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
- C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
- C04B41/5025—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials with ceramic materials
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- C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
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Definitions
- NANOSKAL1GE COROD POWDER SINTER BODIES MADE THEREOF AND METHOD FOR THE PRODUCTION THEREOF
- the invention relates to nanoscale corundum powder, a process for their production and their processing into sintered bodies.
- Powdered corundum ( ⁇ - Al 2 O 3 ) is an important raw material for the production of aluminum oxide ceramics, which can basically be done in two ways.
- One way starts with shaped bodies that are made directly from corundum powder ( ⁇ -AI 2 0 3 powder), the other from shaped bodies that consist of an -AI 2 0 3 precursor (for example, the ⁇ or ⁇ phase) , which is then converted in situ into the ⁇ -AI 0 3 phase.
- the sintering temperature of the corundum is between 1300 and 1600 ° C, depending on the size of the starting particles used.
- the most important obstacle to this is the high activation energy of the homogeneous nucleation, which is kinetically strongly delayed, so that the other Al 2 0 3 phases (e.g.
- US-A-4657754 describes nanoscale corundum having an average particle size of 20 and 50 nm (jr nanocorundum "), which is produced by seeding, so that the synthesis temperature may be reduced so that at 1000 ° C ⁇ -AI 2 0 3 -Powder with a density of 3.78 g / cm 3 (corresponds to 95% of the theoretical density) is present.
- Weng et al. describe another method from salt solutions in CN-A-085187, which likewise gives nanocorundus with a diameter of 10 to 15 nm at synthesis temperatures of 1100 to 1300 ° C.
- a synthesis temperature of 1000 ° C is too high for many purposes, in particular for cofiring processes in microelectronics with foils or the sealing sintering of pastes.
- the synthesis temperature can be reduced to values below 1000 ° C. by means of a special process technology, an only weakly agglomerated nanoscale corundum powder being obtained which can be sintered at lower sintering temperatures.
- This seemingly minor improvement is of eminent technical importance, since it enables a much broader field of application to be worked on.
- new multi-layer systems can be processed in a single cofiring step (which previously required several sintering steps at higher temperatures), since all the multilayer elements contained can now be compressed at the lower sintering temperature.
- the invention relates to a process for the preparation of nanoscale corundum powders, in which one first produces an Al 2 0 3 precursor by adding an aqueous solution of an aluminum compound with seed crystals and adding a base and the Al 2 O 3 precursor then by calcining at elevated temperatures The temperature is converted to corundum, which is characterized in that the salts present in addition to the Al 2 O 3 precursor are separated off before the calcination, the product obtained is calcined at temperatures from 700 to 975 ° C. and any fines present ( ⁇ 40 nm) are removed ,
- Aluminum compounds suitable for producing the Al 2 O 3 precursor are preferably water-soluble aluminum salts such as aluminum (IH) nitrate, aluminum (III) chloride, aluminum (III) acetate or aluminum (III) ethylate. These aluminum compounds are dissolved, for example, in deionized water and seed crystals are added, which preferably have a particle size ⁇ 100 nm. Examples of suitable germs are corundum or diasporic germs.
- the desired Al 2 O 3 precursor which is required for conversion to corundum at temperatures below 1000 ° C., is formed during a ripening period.
- bases which can be used are inorganic or organic bases, such as sodium, potassium, calcium or magnesium hydroxide, ammonia, urea, aliphatic and aromatic amines, thermally separable bases such as ammonia being particularly preferred.
- the precipitation or ripening usually takes place at temperatures of 50 to 100 ° C., preferably 70 to 90 ° C. and particularly preferably 80 to 90 ° C., over a period of 20 to 145 hours, preferably 60 to 90 hours and particularly preferably 70 to 80 hours.
- the n-corundum is preferably produced using the following two alternative methods.
- the aqueous solvent is preferably removed by freeze-drying and the salts contained as impurities are thermally decomposed at temperatures of 150 to 500 ° C., for example 400 ° C.
- the product obtained is mechanically comminuted and converted into ⁇ -Al 2 O 3 by calcining at temperatures from 700 to 975 ° C., preferably 750 to 950 ° C. and in particular 800 to 900 ° C.
- Caicination is usually carried out over a period of 1 to 3 hours.
- the corundum powder obtained by method 1 is characterized by a high
- Corundum content but as a secondary phase still contains a small fine fraction ( ⁇ 40 nm), which mainly consists of non- ⁇ -Al 2 0 3 phases. It is essential to the invention to at least largely remove this fine fraction by a later one To enable compaction of the nanoscale corundum powder at sintering temperatures ⁇ 1200 ° C.
- the fine fraction is preferably removed by centrifugation.
- the corundum powder produced is dispersed in aqueous solution with the aid of a dispersant (surface modifier) and then centrifuged one or more times.
- Suitable dispersants are, for example, inorganic acids (preferably HNO 3 ), aromatic or aliphatic mono-, di- or polycarboxylic acids, aromatic or aliphatic oxacarboxylic acids, such as trioxadecanoic acids (TODS), ⁇ -dicarbonyl compounds and amino acids.
- the dispersant concentration is adapted to the specific surface of the synthesized corundum powder, so that, for example, 4-5 ⁇ mol of dispersant are available per m 2 Al 2 O 3 surface.
- the existing salt load is reduced or removed by dialysis.
- the solution containing the AI 2 0 3 precursor is filled into dialysis tubes and stored in deionized water.
- the dialyzed solution is then frozen and freeze-dried.
- the powder obtained can, if necessary, be calcined at 150 to 500.degree. C. (for example 400.degree. C.) to completely remove the salt content still present.
- the powder is converted into ⁇ -Al 2 O 3 by calcining at temperatures from 700 to 975 ° C., preferably 750 to 950 ° C. and in particular 800 to 900 ° C.
- ⁇ -Al 2 0 3 powder obtained after surface modification with suitable surface modifiers such as inorganic acids (preferably HN0 3 ), .aromatic or aliphatic mono-, di- or polycarboxylic acids, aromatic or aliphatic oxacarboxylic acids, for example trioxadecanoic acids (TODS), ⁇ -dicarbonyl compounds or amino acids, can be compressed directly at sintering temperatures ⁇ 1200 ° C.
- suitable surface modifiers such as inorganic acids (preferably HN0 3 ), .aromatic or aliphatic mono-, di- or polycarboxylic acids, aromatic or aliphatic oxacarboxylic acids, for example trioxadecanoic acids (TODS), ⁇ -dicarbonyl compounds or amino acids
- the amount of surface modifier is the specific surface of the synthesized corundum powder adapted so that, for example, 4-5 ⁇ mol of dispersant are available per m 2 Al 2 O 3 surface.
- the surface can be modified, for example, using a ball mill (3-4 h, aluminum oxide grinding balls ⁇ 1 mm), mortar mills, three-roller mill or kneading unit, adapted to the subsequent shaping technique.
- the average primary particle size is usually 30 to 150 nm, preferably 40 to 100 nm and particularly preferably 50 to 70 nm.
- the corundum powder is only slightly agglomerated in the redispersed state. It has a phase purity (content of ⁇ -Al 2 0 3 ) of> 80, preferably> 90 and in particular> 95% by weight and a density of> 3.90 g / cm 3 , preferably 3 3.93 g / cm 3 , particularly preferably> 3.95 g / cm 3 .
- the corundum powder produced according to the invention is used for further shaping with conventional processing aids, e.g. organic solvents, binders, plasticizers, mixed.
- suitable solvents are e.g. Ethylene glycol, diethylene glycol monobutyl ether and diethylene glycol monoethyl ether, individually or as mixtures.
- binders which can be used are cellulose derivatives such as hydroxypropyl cellulose, polyvinylpyrrolidone, acrylate polymers and oligomers,
- Methacrylates such as tetraethylene glycol dimethacrylate and polyethylene glycoidimethacrylate. The following are used e.g. 15% by weight of binder, based on the weighed solid.
- binder e.g. 15% by weight of binder, based on the weighed solid.
- polyethylene glycol dimethacrylates, polyethylene glycols e.g. PEG 600, PEG 800, PEG 1000, PEG 2000, PEG 6000
- plasticizers e.g. PEG 600, PEG 800, PEG 1000, PEG 2000, PEG 6000
- 25% by weight based on the weighed-in binder.
- the nanoscale corundum powders according to the invention are suitable for producing dense Al 2 O 3 sintered bodies in the form of components or constituents of multilayer structures.
- Special application areas of these components and Multi-layer systems are (micro) electronics, sensors (gas, pressure, piezo sensors), microsystem technology (eg microreactors), ceramic filter elements and catalyst carriers.
- the solution obtained is frozen (for example at -30 ° C.) and then dried (freeze-drying).
- the powder is then heated to 400 ° C. (air atmosphere) at a heating rate of 2 K / min and kept at this temperature for 1 h.
- the powder is ground dry in a mortar mill for 1 hour.
- the powder is then brought to 800 ° C. at a heating rate of 10 K / min and immediately heated to 900 ° C. at a heating rate of 2 K / min and kept at this temperature for 1 hour.
- the powder produced in this way has a specific surface area of approximately 20-60 m 2 / g and a density of 3.6-3.9 g / cm 3 , depending on the germs used.
- the powder After cooling, the powder is dispersed for 3-4 hours in a ball mill with aluminum oxide grinding balls ( ⁇ 1 mm) and an organic acid (TODS) as a dispersant / surface modifier.
- the dispersant content is adapted to the specific surface of the synthesized aluminum oxide powder, so that 4-5 ⁇ mol TODS per m 2 Al 2 O 3 surface are contained.
- the fine fraction of the aluminum oxide powder obtained is separated off by repeated centrifugation.
- the separation limit for centrifugation is arithmetically a particle size of approximately 40 nm.
- the fine fraction consists predominantly (> 90%) of non- ⁇ -Al 2 0 3 particles.
- the centrifugate is freeze-dried to remove the solvent.
- the resulting solution is purified by dialysis in portions containing approximately 400 g ammonium nitrate to remove the dissolved ammonium nitrate ions.
- the solution is poured into a dialysis tube (pore size 2.5 - 3 nmj and approx.
- a hold period of 1 is inserted at 900 ° C.
- the powder thus produced has a specific surface area of approx. 18-22 m 2 / g and a density of 3.95-3.98 g / cm 3 .
- the primary particle size is between 40-70 nm, the powder is weakly agglomerated in the redispersed state.
- Example 1 10.5 g of the ⁇ -Al 2 0 3 prepared in Example 1 are homogeneously mixed together with 2.8 g of a 1: 1 solvent mixture of ethylene glycol and diethylene glycol monobutyl ether and 0.5 g of polyvinylpyrrolidone as a binder. Mortars, kneaders or mortar mills can be used as mixing units. The paste obtained is applied several times to a three-roll mill for the final homogenization.
- the aluminum oxide paste is applied using a thick-film process (screen printing) to already sintered corundum substrates or green (unsintered) substrates made of yttrium-stabilized (3 mol% Y 2 0 3 ) zirconium dioxide in dry layer thicknesses of up to 30 ⁇ m and dried without cracks in a circulating air drying cabinet at 80 ° C.
- the printed layers on the corundum substrates are thermally compacted at 1200 ° C (heating rate 5K / min) with a holding time of 1 hour.
- the compression of the ⁇ -Al 2 0 3 layers printed on green (unsintered) substrates made of yttrium-stabilized zirconium dioxide takes place in two stages.
- the organic matter contained in the composite is removed in a protective gas atmosphere (nitrogen) at temperatures up to 450 ° C by thermal decomposition.
- the heating up time is 10 hours, holding time 3 hours.
- the thermal compression up to the dense material composite takes place in an atmosphere furnace at temperatures of
- Example 2 5 2 g of the -Al 2 0 3 powder produced in Example 1 are homogeneously mixed with 1 g of a solvent mixture of ethylene glycol / diethylene glycol monobutyl ether (1: 1) and 0.15 g of a cellulose binder and dried at 100 ° C. 200 mg of the mixture are compressed in a uniaxial pressing tool with an inner diameter of 5 mm at a pressure of 200 MPa. Then ⁇ Q is post-compressed in a cold isostatic press at 400 MPa. The compact is thermally compressed at 1200 ° C (1h) in an air atmosphere. After sintering, the shaped body has a density of 3.85 g / cm 3 (96.5% of theory).
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Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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DE10035679 | 2000-07-21 | ||
DE10035679A DE10035679A1 (en) | 2000-07-21 | 2000-07-21 | Nanoscale corundum powder, sintered bodies made therefrom and process for their production |
PCT/EP2001/008422 WO2002008124A2 (en) | 2000-07-21 | 2001-07-20 | Nanoscale corundum powders, sintered compacts produced from these powders and method for producing the same |
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Publication Number | Publication Date |
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EP1301434A2 true EP1301434A2 (en) | 2003-04-16 |
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EP01960526A Withdrawn EP1301434A2 (en) | 2000-07-21 | 2001-07-20 | Nanoscale corundum powders, sintered compacts produced from these powders and method for producing the same |
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US (1) | US7022305B2 (en) |
EP (1) | EP1301434A2 (en) |
JP (1) | JP2004504256A (en) |
AU (1) | AU2001282003A1 (en) |
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Families Citing this family (47)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2838804B1 (en) * | 2002-04-18 | 2004-06-18 | Renault Sa | METHOD AND DEVICE FOR PRODUCING A PRESSURE SENSOR INTEGRATED IN A TANK |
DE10304849A1 (en) * | 2003-02-06 | 2004-08-19 | Institut für Neue Materialien gemeinnützige Gesellschaft mit beschränkter Haftung | Chemomechanical production of functional colloids |
JP4534524B2 (en) * | 2003-02-26 | 2010-09-01 | 住友化学株式会社 | Method for producing fine α-alumina |
TWI348457B (en) * | 2003-03-04 | 2011-09-11 | Sumitomo Chemical Co | Method for producing 帢-alumina particulate |
JP4552454B2 (en) * | 2003-03-04 | 2010-09-29 | 住友化学株式会社 | Method for producing fine α-alumina |
US20040198584A1 (en) * | 2003-04-02 | 2004-10-07 | Saint-Gobain Ceramics & Plastic, Inc. | Nanoporous ultrafine alpha-alumina powders and freeze drying process of preparing same |
US7422730B2 (en) * | 2003-04-02 | 2008-09-09 | Saint-Gobain Ceramics & Plastics, Inc. | Nanoporous ultrafine α-alumina powders and sol-gel process of preparing same |
JP4572576B2 (en) * | 2003-05-19 | 2010-11-04 | 住友化学株式会社 | Method for producing fine α-alumina |
JP4595383B2 (en) * | 2003-05-19 | 2010-12-08 | 住友化学株式会社 | Production method of fine α-alumina |
TW200427631A (en) * | 2003-05-19 | 2004-12-16 | Sumitomo Chemical Co | Method for producing α-alumina powder |
DE10332775A1 (en) * | 2003-07-17 | 2005-02-17 | Sasol Germany Gmbh | Process for the preparation of boehmitic clays with a high a-transformation temperature |
TW200531924A (en) * | 2004-03-12 | 2005-10-01 | Sumitomo Chemical Co | Method for producing α-alumina particle |
TW200540116A (en) * | 2004-03-16 | 2005-12-16 | Sumitomo Chemical Co | Method for producing an α-alumina powder |
TWI367864B (en) * | 2004-03-17 | 2012-07-11 | Sumitomo Chemical Co | A method for producing an α-alumina particle |
US7713896B2 (en) * | 2004-04-14 | 2010-05-11 | Robert Bosch Gmbh | Method for producing ceramic green compacts for ceramic components |
TW200604100A (en) * | 2004-06-15 | 2006-02-01 | Sumitomo Chemical Co | A method for producing an α-alumina powder |
JP4670279B2 (en) * | 2004-08-25 | 2011-04-13 | 住友化学株式会社 | Alpha alumina powder for magnetic recording media |
JP4810828B2 (en) * | 2004-09-03 | 2011-11-09 | 住友化学株式会社 | Method for producing fine α-alumina |
TWI408104B (en) * | 2005-03-18 | 2013-09-11 | Sumitomo Chemical Co | Process for producing fine α-alumina particles |
DE102005033393B4 (en) | 2005-07-16 | 2014-04-03 | Clariant International Limited | Process for the preparation of nanocrystalline α-Al 2 O 3 |
DE102006020515B4 (en) * | 2006-04-29 | 2008-11-27 | Clariant International Limited | Nanoparticles of aluminum oxide and oxides of elements of the I. and II. Main group of the Periodic Table and their preparation |
DE102005033392B4 (en) * | 2005-07-16 | 2008-08-14 | Center For Abrasives And Refractories Research & Development C.A.R.R.D. Gmbh | Nanocrystalline sintered bodies based on alpha alumina, process for their preparation and their use |
JP2007055888A (en) * | 2005-07-25 | 2007-03-08 | Sumitomo Chemical Co Ltd | FINE alpha-ALUMINA PARTICLE |
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US8142619B2 (en) | 2007-05-11 | 2012-03-27 | Sdc Materials Inc. | Shape of cone and air input annulus |
US8481449B1 (en) | 2007-10-15 | 2013-07-09 | SDCmaterials, Inc. | Method and system for forming plug and play oxide catalysts |
US9149797B2 (en) | 2009-12-15 | 2015-10-06 | SDCmaterials, Inc. | Catalyst production method and system |
US8545652B1 (en) | 2009-12-15 | 2013-10-01 | SDCmaterials, Inc. | Impact resistant material |
US8652992B2 (en) | 2009-12-15 | 2014-02-18 | SDCmaterials, Inc. | Pinning and affixing nano-active material |
US9039916B1 (en) | 2009-12-15 | 2015-05-26 | SDCmaterials, Inc. | In situ oxide removal, dispersal and drying for copper copper-oxide |
US8557727B2 (en) * | 2009-12-15 | 2013-10-15 | SDCmaterials, Inc. | Method of forming a catalyst with inhibited mobility of nano-active material |
US8470112B1 (en) | 2009-12-15 | 2013-06-25 | SDCmaterials, Inc. | Workflow for novel composite materials |
US8803025B2 (en) | 2009-12-15 | 2014-08-12 | SDCmaterials, Inc. | Non-plugging D.C. plasma gun |
US9126191B2 (en) | 2009-12-15 | 2015-09-08 | SDCmaterials, Inc. | Advanced catalysts for automotive applications |
EP2539475B1 (en) | 2010-02-24 | 2019-09-11 | Belenos Clean Power Holding AG | Self-monitoring composite vessel for high pressure media |
ES2374479B1 (en) * | 2010-08-06 | 2012-12-26 | Universitat De Valencia | PROCEDURE FOR OBTAINING NANOCRISTALINE CORINDON FROM NATURAL OR SYNTHETIC STUDENTS. |
US8669202B2 (en) | 2011-02-23 | 2014-03-11 | SDCmaterials, Inc. | Wet chemical and plasma methods of forming stable PtPd catalysts |
CN103945919A (en) | 2011-08-19 | 2014-07-23 | Sdc材料公司 | Coated substrates for use in catalysis and catalytic converters and methods of coating substrates with washcoat compositions |
US9156025B2 (en) | 2012-11-21 | 2015-10-13 | SDCmaterials, Inc. | Three-way catalytic converter using nanoparticles |
US9511352B2 (en) | 2012-11-21 | 2016-12-06 | SDCmaterials, Inc. | Three-way catalytic converter using nanoparticles |
EP3024571B1 (en) | 2013-07-25 | 2020-05-27 | Umicore AG & Co. KG | Washcoats and coated substrates for catalytic converters |
US9517448B2 (en) | 2013-10-22 | 2016-12-13 | SDCmaterials, Inc. | Compositions of lean NOx trap (LNT) systems and methods of making and using same |
JP2016536120A (en) | 2013-10-22 | 2016-11-24 | エスディーシーマテリアルズ, インコーポレイテッド | Catalyst design for heavy duty diesel combustion engines |
CN103570049B (en) * | 2013-11-12 | 2015-07-15 | 兰州大学 | Method for preparing completely dispersed alpha aluminum oxide nano particles |
US9687811B2 (en) | 2014-03-21 | 2017-06-27 | SDCmaterials, Inc. | Compositions for passive NOx adsorption (PNA) systems and methods of making and using same |
CN108059447A (en) * | 2018-01-08 | 2018-05-22 | 浙江自立新材料股份有限公司 | A kind of big crystallization sintering plate corundum and preparation method thereof |
CN115010469A (en) * | 2022-06-22 | 2022-09-06 | 潮州市三泰陶瓷有限公司 | Wear-resistant ceramic material with high hardness and preparation process thereof |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000069790A2 (en) * | 1999-05-14 | 2000-11-23 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method of producing aluminum oxides and products obtained on the basis thereof |
Family Cites Families (68)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US36323A (en) * | 1862-08-26 | Water-wheel | ||
US2287099A (en) * | 1937-02-15 | 1942-06-23 | Du Pont | Artificial wool |
US2197896A (en) * | 1937-02-15 | 1940-04-23 | Du Pont | Artificial wool |
US2774129A (en) * | 1950-11-06 | 1956-12-18 | Kendall & Co | Synthetic felts |
MX65223A (en) * | 1954-02-26 | |||
US3338992A (en) * | 1959-12-15 | 1967-08-29 | Du Pont | Process for forming non-woven filamentary structures from fiber-forming synthetic organic polymers |
UST859640I4 (en) * | 1959-12-15 | 1900-01-01 | ||
BE620334A (en) * | 1961-07-17 | 1900-01-01 | ||
US3502763A (en) * | 1962-02-03 | 1970-03-24 | Freudenberg Carl Kg | Process of producing non-woven fabric fleece |
GB1073183A (en) * | 1963-02-05 | 1967-06-21 | Ici Ltd | Leather-like materials |
GB1034207A (en) * | 1963-09-24 | 1966-06-29 | British Nylon Spinners Ltd | Improvements in or relating to nonwoven fabrics and the method of manufacture thereof |
GB1088931A (en) * | 1964-01-10 | 1967-10-25 | Ici Ltd | Continuous filament nonwoven materials |
GB1118163A (en) * | 1964-07-30 | 1968-06-26 | Ici Ltd | Non-woven fabrics and methods of making them |
US3402227A (en) * | 1965-01-25 | 1968-09-17 | Du Pont | Process for preparation of nonwoven webs |
US3272898A (en) * | 1965-06-11 | 1966-09-13 | Du Pont | Process for producing a nonwoven web |
US3589956A (en) * | 1966-09-29 | 1971-06-29 | Du Pont | Process for making a thermally self-bonded low density nonwoven product |
US3533904A (en) * | 1966-10-19 | 1970-10-13 | Hercules Inc | Composite polypropylene filaments having a high degree of crimp |
US3341394A (en) * | 1966-12-21 | 1967-09-12 | Du Pont | Sheets of randomly distributed continuous filaments |
US3542615A (en) * | 1967-06-16 | 1970-11-24 | Monsanto Co | Process for producing a nylon non-woven fabric |
US3616160A (en) * | 1968-12-20 | 1971-10-26 | Allied Chem | Dimensionally stable nonwoven web and method of manufacturing same |
US3849241A (en) * | 1968-12-23 | 1974-11-19 | Exxon Research Engineering Co | Non-woven mats by melt blowing |
DE2048006B2 (en) * | 1969-10-01 | 1980-10-30 | Asahi Kasei Kogyo K.K., Osaka (Japan) | Method and device for producing a wide nonwoven web |
DE1950669C3 (en) * | 1969-10-08 | 1982-05-13 | Metallgesellschaft Ag, 6000 Frankfurt | Process for the manufacture of nonwovens |
CA948388A (en) * | 1970-02-27 | 1974-06-04 | Paul B. Hansen | Pattern bonded continuous filament web |
US3773605A (en) * | 1971-03-05 | 1973-11-20 | Minnesota Mining & Mfg | Acoustical material |
CA1073648A (en) * | 1976-08-02 | 1980-03-18 | Edward R. Hauser | Web of blended microfibers and crimped bulking fibers |
USD264512S (en) * | 1980-01-14 | 1982-05-18 | Kimberly-Clark Corporation | Embossed continuous sheet tissue-like material or similar article |
US4340563A (en) * | 1980-05-05 | 1982-07-20 | Kimberly-Clark Corporation | Method for forming nonwoven webs |
US4732809A (en) * | 1981-01-29 | 1988-03-22 | Basf Corporation | Bicomponent fiber and nonwovens made therefrom |
US4374888A (en) * | 1981-09-25 | 1983-02-22 | Kimberly-Clark Corporation | Nonwoven laminate for recreation fabric |
US4787947A (en) * | 1982-09-30 | 1988-11-29 | Chicopee | Method and apparatus for making patterned belt bonded material |
US4493868A (en) * | 1982-12-14 | 1985-01-15 | Kimberly-Clark Corporation | High bulk bonding pattern and method |
IT1184114B (en) * | 1985-01-18 | 1987-10-22 | Montedison Spa | ALFA ALUMINATES IN THE FORM OF SPHERICAL PARTICLES, NOT AGGREGATED, WITH RESTRIBUTION GRANULOMETRIC RESTRICTED AND OF LESS THAN 2 MICRONS, AND PROCESS FOR ITS PREPARATION |
CA1254238A (en) * | 1985-04-30 | 1989-05-16 | Alvin P. Gerk | Process for durable sol-gel produced alumina-based ceramics, abrasive grain and abrasive products |
US4657754A (en) | 1985-11-21 | 1987-04-14 | Norton Company | Aluminum oxide powders and process |
US4659609A (en) * | 1986-05-02 | 1987-04-21 | Kimberly-Clark Corporation | Abrasive web and method of making same |
US4845056A (en) | 1987-10-09 | 1989-07-04 | Allied-Signal Inc. | Continuous process for production of fine particulate ceramics |
US4883707A (en) * | 1988-04-21 | 1989-11-28 | James River Corporation | High loft nonwoven fabric |
US5082720A (en) * | 1988-05-06 | 1992-01-21 | Minnesota Mining And Manufacturing Company | Melt-bondable fibers for use in nonwoven web |
US5198057A (en) * | 1988-12-23 | 1993-03-30 | Fiberweb North America, Inc. | Rebulkable nonwoven fabric |
US5143779A (en) * | 1988-12-23 | 1992-09-01 | Fiberweb North America, Inc. | Rebulkable nonwoven fabric |
JP2682130B2 (en) * | 1989-04-25 | 1997-11-26 | 三井石油化学工業株式会社 | Flexible long-fiber non-woven fabric |
US5108827A (en) * | 1989-04-28 | 1992-04-28 | Fiberweb North America, Inc. | Strong nonwoven fabrics from engineered multiconstituent fibers |
DE4116522C2 (en) * | 1990-05-23 | 1994-08-18 | Fraunhofer Ges Forschung | Process for the production of substrates provided with a porous alpha-Al¶2¶O¶3¶ layer, substrates obtained by the process and coating compositions for carrying out the process |
ES2091296T3 (en) * | 1990-12-14 | 1996-11-01 | Hercules Inc | HIGH STRENGTH AND VOLUMINOSITY NON-WOVEN FABRIC. |
AU650382B2 (en) | 1992-02-05 | 1994-06-16 | Norton Company | Nano-sized alpha alumina particles |
US5270107A (en) * | 1992-04-16 | 1993-12-14 | Fiberweb North America | High loft nonwoven fabrics and method for producing same |
US5382400A (en) * | 1992-08-21 | 1995-01-17 | Kimberly-Clark Corporation | Nonwoven multicomponent polymeric fabric and method for making same |
JP3245170B2 (en) * | 1992-08-24 | 2002-01-07 | ミネソタ マイニング アンド マニュファクチャリング カンパニー | Melt-bonded nonwoven product and method of making same |
US5405682A (en) * | 1992-08-26 | 1995-04-11 | Kimberly Clark Corporation | Nonwoven fabric made with multicomponent polymeric strands including a blend of polyolefin and elastomeric thermoplastic material |
US5336552A (en) * | 1992-08-26 | 1994-08-09 | Kimberly-Clark Corporation | Nonwoven fabric made with multicomponent polymeric strands including a blend of polyolefin and ethylene alkyl acrylate copolymer |
CA2105026C (en) * | 1993-04-29 | 2003-12-16 | Henry Louis Griesbach Iii | Shaped nonwoven fabric and method for making the same |
CN1031396C (en) | 1993-07-20 | 1996-03-27 | 浙江大学 | Method for preparing alpha-alumina particles with nanometers size |
EP0678489A1 (en) * | 1994-04-19 | 1995-10-25 | Fraunhofer-Gesellschaft Zur Förderung Der Angewandten Forschung E.V. | Sintered alumina and procces for its production |
US5622772A (en) * | 1994-06-03 | 1997-04-22 | Kimberly-Clark Corporation | Highly crimpable spunbond conjugate fibers and nonwoven webs made therefrom |
US5707468A (en) * | 1994-12-22 | 1998-01-13 | Kimberly-Clark Worldwide, Inc. | Compaction-free method of increasing the integrity of a nonwoven web |
US5759213A (en) | 1995-04-24 | 1998-06-02 | University Of Florida | Method for controlling the size and morphology of alpha-alumina particles |
US5759926A (en) * | 1995-06-07 | 1998-06-02 | Kimberly-Clark Worldwide, Inc. | Fine denier fibers and fabrics made therefrom |
DE69607164T2 (en) * | 1995-06-23 | 2000-11-23 | Minnesota Mining & Mfg | SOUND INSULATION METHOD AND SOUND INSULATION ITEM |
US5672415A (en) * | 1995-11-30 | 1997-09-30 | Kimberly-Clark Worldwide, Inc. | Low density microfiber nonwoven fabric |
US5858515A (en) * | 1995-12-29 | 1999-01-12 | Kimberly-Clark Worldwide, Inc. | Pattern-unbonded nonwoven web and process for making the same |
US5773375A (en) * | 1996-05-29 | 1998-06-30 | Swan; Michael D. | Thermally stable acoustical insulation |
US5879343A (en) * | 1996-11-22 | 1999-03-09 | Kimberly-Clark Worldwide, Inc. | Highly efficient surge material for absorbent articles |
US6200669B1 (en) * | 1996-11-26 | 2001-03-13 | Kimberly-Clark Worldwide, Inc. | Entangled nonwoven fabrics and methods for forming the same |
US5874160A (en) * | 1996-12-20 | 1999-02-23 | Kimberly-Clark Worldwide, Inc. | Macrofiber nonwoven bundle |
US5931823A (en) * | 1997-03-31 | 1999-08-03 | Kimberly-Clark Worldwide, Inc. | High permeability liner with improved intake and distribution |
AUPP355798A0 (en) * | 1998-05-15 | 1998-06-11 | University Of Western Australia, The | Process for the production of ultrafine powders |
US6217691B1 (en) * | 1998-12-24 | 2001-04-17 | Johns Manville International, Inc. | Method of making a meltblown fibrous insulation |
-
2000
- 2000-07-21 DE DE10035679A patent/DE10035679A1/en not_active Ceased
-
2001
- 2001-07-20 WO PCT/EP2001/008422 patent/WO2002008124A2/en active Application Filing
- 2001-07-20 AU AU2001282003A patent/AU2001282003A1/en not_active Abandoned
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- 2001-07-20 US US10/312,474 patent/US7022305B2/en not_active Expired - Fee Related
- 2001-07-20 EP EP01960526A patent/EP1301434A2/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000069790A2 (en) * | 1999-05-14 | 2000-11-23 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method of producing aluminum oxides and products obtained on the basis thereof |
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US7022305B2 (en) | 2006-04-04 |
WO2002008124A3 (en) | 2002-09-19 |
DE10035679A1 (en) | 2002-01-31 |
JP2004504256A (en) | 2004-02-12 |
US20030098529A1 (en) | 2003-05-29 |
AU2001282003A1 (en) | 2002-02-05 |
WO2002008124A2 (en) | 2002-01-31 |
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