Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
  • B01J35/39—Photocatalytic properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • 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
  • C04B41/5041—Titanium oxide or titanates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • 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
  • C04B41/52—Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
  • C04B41/81—Coating or impregnation
  • C04B41/85—Coating or impregnation with inorganic materials
  • C04B41/87—Ceramics
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
  • C04B41/81—Coating or impregnation
  • C04B41/89—Coating or impregnation for obtaining at least two superposed coatings having different compositions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/61—Surface area
  • B01J35/613—10-100 m2/g
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/61—Surface area
  • B01J35/615—100-500 m2/g
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00586—Roofing materials
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/20—Resistance against chemical, physical or biological attack
  • C04B2111/2038—Resistance against physical degradation
  • C04B2111/2061—Materials containing photocatalysts, e.g. TiO2, for avoiding staining by air pollutants or the like
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
  • Y10T428/24372—Particulate matter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249967—Inorganic matrix in void-containing component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249967—Inorganic matrix in void-containing component
  • Y10T428/249969—Of silicon-containing material [e.g., glass, etc.]

Definitions

• the invention concerns a ceramic molded body of oxide-ceramic base material with a surface which is self-cleaning upon spraying or sprinkling with water and a process for the production thereof.
• EP 0 590 477 B1 discloses a building material which can be for example an outside wall material or roof material, wherein a thin metal oxide film with a photocatalytic action is applied on the surface of the building material.
• the metal oxide film is preferably applied by means of sol-gel processes.
• a titanium dioxide thin film building material is preferably produced using titanium dioxide sol.
• the thin metal oxide film known from EP 0 590 477 B1 has deodorosing anti-mold properties.
• the metal oxide film known from EP 0 590 477 B1 is of a small surface area and accordingly has a low level of catalytic activity.
• DE 199 11 738 A1 discloses a titanium dioxide photocatalyst which is doped with Fe 3+ ions and which has a content of pentavalent ions, which is equimolar or approximately equimolar in relation to the Fe 3+ ions.
• the titanium dioxide photocatalyst known from DE 199 11 738 A1 and doped with Fe 3+ ions is produced by way of sol-gel processes.
• EP 0 909 747 A1 discloses a process for producing a self-cleaning property of surfaces, in particular the surface of roof tiles, upon being sprayed or sprinkled with water.
• the surface has hydrophobic raised portions of a height of between 5 and 200 ⁇ m in distributed form. To produce those raised portions, a surface is wetted with a dispersion of powder particles of inert material in a siloxane solution and the siloxane is then hardened.
• the process known from EP 0 909 747 A1 makes it possible to produce a ceramic body having a surface to which particles of dirt can cling poorly.
• the ceramic body known from EP 0 909 747 A1 does not have any catalytic activity whatsoever.
• WO 01/79141 A1 discloses a further process for producing a self-cleaning property of a surface and an article produced with that process.
• a metallorganic compound of titanium oxide is applied to a surface by means of a sol-gel process, the surface is dried and then subjected to heat treatment at elevated temperature.
• the surface of the titanium oxide layer can be subsequently hydrophobised.
• the object of the present invention is to provide a molded body, in particular roof materials, which has an improved self-cleaning capability and improved stability such as for example improved resistance to abrasion.
• a further object of the invention is to provide a process for the production of such an improved ceramic molded body.
• the object of the invention is attained by a ceramic molded body of oxide-ceramic base material with a surface which is self-cleaning upon spraying or sprinkling with water, wherein the molded body has a porous oxide-ceramic coating, wherein the coating is photocatalytically active and has a specific surface area in a range of between about 25 mg 2 /g and about 200 m 2 /g, preferably between about 40 m 2 /g and about 150 m 2 /g.
• the object of the invention is further attained by a process for the production of a ceramic molded body of oxide-ceramic base material with a surface which is self-cleaning upon spraying or sprinkling with water, wherein the molded body has a photocatalytically active, porous, oxide-ceramic coating with a specific surface area in a range of between about 25 m 2 /g and about 200 m 2 /g, preferably about 40 m 2 /g and about 150 m 2 /g, wherein the process includes the following steps:
• step a) applying the suspension produced in step a) to the oxide-ceramic base material to produce a layer
• step (c) hardening the layer afforded in step (b) to produce a photocatalytically active, porous, oxide-ceramic coating.
• the ceramic molded body produced using the process according to the invention involves a highly suitable porosity and stability.
• a suspension of photocatalytically active, oxide-ceramic powder with further components is applied to an oxide-ceramic base material. This therefore does not involve producing a film but a porous structure of large specific surface area.
• the structure produced is a highly porous structure, that is to say the specific surface area of the catalytically active, porous, oxide-ceramic coating is in a range of between 25 m 2 /g and 200 m 2 /g, further preferably in a range of between about 40 m 2 /g and about 150 m 2 /g. More preferably the specific surface area is in a range of between 40 m 2 /g and about 100 m 2 /g.
• the mean layer thickness of the oxide-ceramic coating is preferably in a range of between about 50 nm and about 50 ⁇ m, further preferably between about 100 nm and about 10 ⁇ m.
• a highly satisfactory catalytic activity is obtained with a layer thickness of about 1 ⁇ m.
• the photocatalytically active, porous, oxide-ceramic coating according to the invention provides that mold, fungal and plant growth, for example moss, algae etc, bacterial contamination etc, which are deposited on or in the ceramic molded body are photochemically broken down and removed.
• the photocatalytic activity of the porous, oxide-ceramic coating is extremely advantageously adequate at ambient temperature to oxidise and thus break down the stated substances and contamination.
• the oxidised substances have a reduced adhesion capability and are easily flushed off the surface of the molded body according to the invention when subjected to the action of spraying or sprinkling with water.
• the photocatalytically active coating can have an oxidative action on the one hand directly on the organic contamination and impurities.
• the oxidative effect of the photocatalytically active coating is effected indirectly by the production of oxygen radicals which subsequently oxidise and accordingly break down the contaminating substances or impurities.
• the self-cleaning action of the ceramic molded body according to the invention can be further enhanced if a surface structure with raised portions or depressions is arranged under the photocatalytically active, porous, oxide-ceramic coating and/or if the photocatalytically active, porous, oxide-ceramic coating itself has a surface structure with raised portions and recesses.
• ceramic surface structures with raised portions preferably involving a predetermined distribution density, have a surprising self-cleaning property.
• the raised portions can also be hydrophobised so that the adhesion of hydrophilic soiling substances or contaminants is further greatly reduced.
• the raised portions can be formed by the application of particulate material to the ceramic base material.
• particulate material preferably selected from the group which consists of crushed stone, fire clay, clay, minerals, ceramic powder such as SiC, glass, glass chamotte, and mixtures thereof.
• TiO 2 , Al 2 O 3 , SiO 2 , and/or Ce 2 O 3 can be used as the particulate material.
• a particle size range of between about 50 nm and about 200 nm is highly preferred.
• the raised portions or recesses are of heights or depths respectively in a range of up to 1500 nm, preferably between about 50 nm and about 700 nm, further preferably between about 50 nm and about 200 nm. In that way the raised portions can also be formed with the aggregation or agglomeration of smaller particles.
• the particulate material can be fixed to the ceramic base material using adhesives.
• the adhesives used can be polysiloxanes which on the one hand fix the particulate material to the surface of the oxide-ceramic base material and on the other hand provide the produced coating with a superhydrophobic surface.
• the adhesive for example the polysiloxane, is added in step (a) of the process according to the invention in production of the suspension.
• step (c) If hydrophobisation of the surface of the coating is to be maintained, in that case the hardening operation in step (c) is not to be effected at a temperature of more than 300° C. If the temperature is increased above 300° C., that can involve thermal decomposition of the polysiloxane and the breakdown of the superhydrophobic surface on the photocatalytically active, porous, oxide-ceramic coating.
• the particulate material used for producing raised portions is subjected to the action of a temperature which results in superficial softening of the particle surfaces so that a sinter-like join is produced between the particulate material and the oxide-ceramic base material.
• a temperature which results in superficial softening of the particle surfaces so that a sinter-like join is produced between the particulate material and the oxide-ceramic base material.
• fluxing agents which reduce the sintering temperature.
• EP 0 909 747, EP 00 115 701 and EP 1 095 023 of various possible ways of fixing particulate material on a ceramic surface.
• the contents of EP 0 909 747, EP 00 115 701 and EP 1 095 923 are hereby incorporated by reference thereto.
• the photocatalytically active, porous, oxide-ceramic coating is formed by using photocatalytically active, oxide-ceramic materials selected from the group consisting of TiO 2 , Al 2 O 3 , SiO 2 , Ce 2 O 3 and mixtures thereof.
• oxide-ceramic materials may also be contained in the oxide-ceramic base body.
• the photocatalytically active, oxide-ceramic material in the coating and/or in the oxide-ceramic base material includes TiO 2 or Al 2 O 3 , optionally in combination with further oxide-ceramic materials.
• TiO 2 or Al 2 O 3 optionally in combination with further oxide-ceramic materials.
• mixtures of titanium dioxide and silicon dioxide, titanium dioxide and aluminum dioxide, aluminum dioxide and silicon dioxide and also titanium dioxide, aluminum oxide and silicon dioxide have been found to be highly suitable.
• titanium dioxide with an anatase structure is used as the titanium dioxide.
• the aluminum oxide used is preferably aluminum oxide C which is to be allocated crystallographically to the ⁇ -group and has a strong oxidation-catalytic effect.
• a suitable aluminum oxide C can be obtained from Degussa AG, Germany.
• AEROSIL COK 84 a mixture of 84% AEROSIL 200 and 16% aluminum oxide C has proven to be very usable in the present invention.
• the TiO 2 is present at least in part in the anatase structure, preferably in respect of at least 40% by weight, preferably in respect of at least 70% by weight, further preferably in respect of at least 80% by weight, with respect to the total amount of TiO 2 .
• TiO 2 which is present in a mixture of about 70-85% by weight anatase and about 30-15% by weight rutile has proven to be highly suitable.
• the TiO 2 used in the present invention is obtained by flame hydrolysis of TiCl 4 in the form of highly disperse TiO 2 which preferably has a particle size of between about 15 nm and 30 nm, preferably 21 nm.
• titanium dioxide which can be obtained under the name titanium dioxide P25 from Degussa AG, Germany and which comprises a proportion of 70% anatase form and 30% rutile.
• titanium dioxide in the anatase form absorbs UV light at wavelengths of less than 385 nm.
• Rutile absorbs UV light at a wavelength of less than 415 nm.
• the ceramic molded body according to the invention has a superhydrophobic surface.
• the self-cleaning property of the surface can be markedly improved if the photocatalytically active, porous, oxide-ceramic coating is provided with a superhydrophobic surface.
• the oxidised organic soiling substances are still more easily flushed away from the surface by spraying or sprinkling with water.
• the term superhydrophobic surface is used to denote a surface with an edge angle of at least 140° for water.
• the edge angle can be determined in conventional manner at a drop of water of a volume of 15 ⁇ l, which is put on to a surface.
• the edge angle is at least 150°, further preferably 160°, still further preferably at least 170°.
• the photocatalytically active, porous, oxide-ceramic coating can be hydrophobised using Ormoceres, polysiloxane, alkylsilane and/or fluorosilane.
• a mixture of SiO 2 and fluorosilane is applied, thereby producing a superhydrophobic surface. That hydrophobising effect or the provision of a superhydrophobic surface is extremely advantageous for the self-cleaning property of the molded body according to the invention.
• the superhydrophobic surface has raised portions. Those raised portions can be produced when applying the hydrophobising agent by a procedure whereby particulate material is added to the hydrophobising agent and that mixture is subsequently applied to the photocatalytically active, porous, oxide-ceramic coating.
• the temperature may not be raised above 300° C. as that can then involve thermal decomposition, which has already been mentioned above, of the hydrophobising agents.
• hardening is effected by calcining only when no hydrophobic surface has yet been applied to the photocatalytically active, porous, oxide-ceramic coating. If polysiloxane were used as an adhesive and subsequently the molded body were hardened by calcining, the surface usually has to be hydrophobised once again if a hydrophobic surface is to be afforded on the photocatalytically active, porous, oxide-ceramic coating.
• the ceramic molded body is in the form of a roof tile, a tile, a clinker brick or a facade wall.
• the photocatalytically active, oxide-ceramic powder used in step (a) is preferably in a nano-disperse form.
• the particle size range of the oxide-ceramic powder in a range of between 5 nm and about 100 nm, further preferably between about 10 nm and about 50 nm, has proven to be highly suitable.
• a preferably homogenous suspension is produced from oxide-ceramic powder, adjusting agent and/or adhesive and a liquid phase, by mixing. That suspension can be applied in a desired layer thickness to the oxide-ceramic base material.
• the suspension may be applied to the oxide-ceramic base material for example by pouring, brushing, spraying, flinging and so forth. It will be appreciated that the oxide-ceramic base material can also be dipped into the suspension.
• the suspension is applied in such a layer thickness that, after the drying and/or calcining operation, the result obtained is a ceramic molded body with a photocatalytically active, porous, oxide-ceramic coating in a thickness of between 50 nm and about 50 ⁇ m, preferably between about 100 nm and about 10 ⁇ m.
• the layer thickness of the undried suspension is usually in a range of between about 0.5 ⁇ m and about 100 ⁇ m.
• the oxide-ceramic base material may be a green body (uncalcined ceramic material) or a pre-calcined or calcined ceramic material.
• organic viscosity regulators for example carboxymethylcellulose
• Those viscosity regulators impart a suitable viscosity to the suspension so that it can be reliably applied to the ceramic base material in the desired layer thickness.
• the organic adjusting agent preferably the carboxymethylcellulose
• Calcination of the layer produced in step (b) can be effected on the one hand by calcining the molded body in a calcining furnace or in a calcining chamber at a temperature of more than 300° C. to about 1100° C.
• the calcining operation is preferably effected in a temperature range of between about 700° C. and about 1100° C.
• the drying operation is effected at a substantially lower temperature than the calcining operation. Drying is usually effected in a temperature range of between 50° C. and 300° C., preferably between 80° C. and 100° C. In that temperature range an applied superhydrophobic coating is not broken down or destroyed.
• polysiloxane which promotes adhesion of the oxide-ceramic powder to the oxide-ceramic base material.
• polysiloxane also results in hydrophobisation of the structure.
• adhesive such as for example polysiloxane also produces an increase in the viscosity of the suspension produced in step (a) of the process according to the invention. Accordingly an adjusting agent does not necessarily have to be added when adding adhesive to the suspension in step (a).
• the viscosity which is adjusted using adhesive can be sufficient so that in step (b) the suspension can be applied to the oxide-ceramic base material, to form a layer.
• the liquid phase used is preferably water.
• particulate material can also be added to the suspension produced in step (a).
• the raised portions which are advantageous in regard to the self-cleaning effect of the surface and also the catalytically active, porous, oxide-ceramic coating are produced in one step.
• a ceramic molded body produced in accordance with this alternative configuration of the process there is then not a separate layer structure consisting of a layer with raised portions and, arranged thereover, catalytically active, porous, oxide-ceramic coating. Rather, the raised portions produced using particulate material and the photocatalytically active, oxide-ceramic components are present in substantially mutually juxtaposed relationship or intimately mixed with each other.
• a hydrophobising agent can then also be added to that suspension so that superhydrophobisation of the oxide-ceramic surface is effected in the same step in the process.
• the hardening operation can then be effected only by drying so that no thermal decomposition of the superhydrophobic surface occurs.
• the above-mentioned particulate material to be applied to the oxide-ceramic base material to produce raised portions and for it to be fixed to the surface of the ceramic base material by means of adhesive and/or sintering, for that surface which is prepared in that way and which has raised portions to be provided with a photocatalytically active, porous, oxide-ceramic coating using the process according to the invention, and for a superhydrophobic surface optionally to be subsequently produced on the photocatalytically active coating.
• hydrophobising agents used are preferably inorganic-organic hybrid molecules such as for example siloxanes, in particular polysiloxanes.
• siloxanes in particular polysiloxanes.
• alkylsilanes and/or fluorosilanes have proven to be suitable as the hydrophobising agents.
• the hydrophobising agents can be applied by a suitable process, for example spraying, pouring, flinging, sprinkling etc.
• a hydrophobising solution or suspension can be produced using a preferably aqueous liquid phase.
• particulate materials can also be added to that hydrophobising solution or suspension if raised portions are to be produced in the superhydrophobic surface. That hydrophobising solution or suspension can then be applied in the above-described conventional manner.
• superhydrophobic surface is used in accordance with the invention to denote a superhydrophobic layer, wherein the edge angle for water is at least 140°, preferably 160°, further preferably 170°.
• a pre-drying step can also be carried out after application of the suspension produced in step (a) to the oxide-ceramic base material, prior to the calcining operation.
• the liquid phase preferably water
• the liquid phase can be removed by evaporation. That can be effected for example by heating, for example in a circulating air furnace or a radiant furnace. It will be appreciated that it is also possible to use other drying processes, for example using microwave technology.
• the pre-drying step has proven to be advantageous in order to avoid cracking or tearing of the layer produced from the suspension, in the calcining operation.
• the post-treatment is effected by irradiation with laser light, or NIR or UV light. That post-treatment can improve the adhesion between the photocatalytically active coating and the oxide-ceramic base material.
• the ceramic molded body according to the invention besides an improved self-cleaning property, also has improved mechanical stability.
• the catalytically active, porous, oxide-ceramic coating with a possibly superhydrophobic surface adheres very firmly and reliably to the ceramic base material.
• that coating is applied for example to roof tiles it is not destroyed or abraded when a person walks on the roof.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Structural Engineering (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Catalysts (AREA)
• Finishing Walls (AREA)
• Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
• Materials For Medical Uses (AREA)
• Immobilizing And Processing Of Enzymes And Microorganisms (AREA)

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• 2003
  • 2003-05-28 DK DK03737918T patent/DK1507751T3/da active
  • 2003-05-28 PT PT03737918T patent/PT1507751E/pt unknown
  • 2003-05-28 DE DE50309883T patent/DE50309883D1/de not_active Expired - Lifetime
  • 2003-05-28 SI SI200331305T patent/SI1507752T1/sl unknown
  • 2003-05-28 DE DE10324518A patent/DE10324518B4/de not_active Expired - Lifetime
  • 2003-05-28 PT PT03755907T patent/PT1507752E/pt unknown
  • 2003-05-28 DK DK03755907T patent/DK1507752T3/da active
  • 2003-05-28 PL PL37361303A patent/PL373613A1/xx not_active Application Discontinuation
  • 2003-05-28 RU RU2004138587A patent/RU2318781C2/ru active
  • 2003-05-28 DE DE10393112T patent/DE10393112D2/de not_active Expired - Fee Related
  • 2003-05-28 AU AU2003243903A patent/AU2003243903A1/en not_active Abandoned
  • 2003-05-28 AT AT03737918T patent/ATE315542T1/de active
  • 2003-05-28 JP JP2004509609A patent/JP2005535544A/ja active Pending
  • 2003-05-28 CN CNB038149982A patent/CN1300063C/zh not_active Expired - Fee Related
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