DE19721697A1

Aqueous ceramic titanium di:oxide coating

Abstract

Aqueous ceramic titanium dioxide coating comprises: (A) orthotitanic acid, titanium (IV) ions or peroxotitanic acid; and (B) colloidal crystalline titanium dioxide particles having an average grain size of 0.001-0.2 microns. The wt. ratio of (A) to (B) is 1:0.1-200. The coating contains no impurity ions. Production of the coating is also claimed and comprises: (a) dialysing an aqueous solution of a titanium salt using a semipermeable membrane; (b) electrodialysing using a semipermeable membrane; (c) ion exchanging using an ion exchanger to hydrolyse a part of the titanium salt to orthotitanium salt and the colloidal crystalline titanium dioxide particles, in which impurity ions are removed from the aqueous titanium salt solution. Also claimed is a process for the production of the coating.

Term

Term ended

Projected expiry passed 23 May 2017, 9.3 years ago.

9 claims: 9 independent, 0 dependent

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Aqueous, ceramic titanium dioxide paint to Preparing a paint coating having excellent Hydrophilicity, photocatalytic activity and light permeability, comprising:(A) at least one member selected from the Grup group consisting of orthotitanic acid, titanium (IV) ions and by oxotitansäure, and(B) colloidal crystalline titanium dioxide particles with an average particle size of 0.001 to 0.2 microns, 1. Wässeriger, keramischer Titandioxidanstrich zur Herstellung einer Anstrichbeschichtung mit ausgezeichneter Hydrophilizität, photokatalytischer Aktivität und Lichtdurch lässigkeit, umfassend: (A) mindestens ein Mitglied, ausgewählt aus der Grup pe, bestehend aus Orthotitansäure, Titan(IV)-Ionen und Per oxotitansäure, und(B) kolloidale, kristalline Titandioxidteilchen mit einer mittleren Teilchengröße von 0,001 bis 0,2 µm, 1. Wässeriger, keramischer Titandioxidanstrich zur Herstellung einer Anstrichbeschichtung mit ausgezeichneter Hydrophilizität, photokatalytischer Aktivität und Lichtdurchlässigkeit, umfassend: (A) mindestens ein Mitglied, ausgewählt aus der Gruppe, bestehend aus Orthotitansäure, Titan(IV)-Ionen und Peroxotitansäure, und (B) kolloidale, kristalline Titandioxidteilchen mit einer mittleren Teilchengröße von 0,001 bis 0,2 µm, wobei das Gewichtsverhältnis der Komponente (A) zur Komponente (B), bezogen auf Titan, 1 : 0,1 bis 1 : 200 ist und der keramische Anstrich im wesentlichen keine Verunreinigungsionen enthält.
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wherein the weight ratio of component (A) to the Component (B), based on titanium, 1:0.1 to 1: 200, and the ceramic paint substantially no contami supply versions contain. wobei das Gewichtsverhältnis der Komponente (A) zur Komponente (B), bezogen auf Titan, 1 : 0,1 bis 1 : 200 ist und der keramische Anstrich im wesentlichen keine Verunreini gungsionen enthält. 2. Wässeriger, keramischer Titandioxidanstrich nach Anspruch 1, wobei die mittlere Teilchengröße der kristallinen Titandioxidteilchen 0,002 bis 0,1 µm beträgt.
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2. Aqueous, ceramic titanium dioxide paint by Claim 1, wherein the average particle size of the crystalline Titanium dioxide 0.002 to 0.1 microns. 2. Wässeriger, keramischer Titandioxidanstrich nach Anspruch 1, wobei die mittlere Teilchengröße der kristallinen Titandioxidteilchen 0,002 bis 0,1 µm beträgt. 3. Verfahren zur Herstellung des wässerigen, keramischen Titandioxidanstrichs nach Anspruch 1, umfassend Unterziehen einer wässerigen Lösung eines Titansalzes mindestens einer Behandlung, ausgewählt aus der Gruppe, bestehend aus:(a) einer Dialysebehandlung unter Verwendung einer semipermeablen Membran, (b) einer Elektrodialysebehandlung unter Verwendung einer semipermeablen Membran, und (c) einer Ionenaustauschbehandlung unter Verwendung eines Ionenaustauschers, um zumindest einen Teil des Titansalzes zu Orthotitansäure und den kolloidalen, kristallinen Titandioxidteilchen zu hydrolysieren und umzuwandeln, wobei Verunreinigungsionen aus der wässerigen Titansalzlösung entfernt werden.
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3. The method for producing the aqueous, Kerami 's titanium dioxide paint according to claim 1, comprising subjecting draw an aqueous solution of a titanium salt at least one treatment selected from the group consisting of:(A) of a dialysis treatment using a semi-permeable membrane,(B) an electrodialysis treatment using a semipermeable membrane, and(C) an ion-exchange treatment using an ion exchanger, at least a portion of the Titanium salt to orthotitanium acid and colloidal kristal linen titanium dioxide to hydrolyze and convert, wherein impurity ions from the aqueous titanium salt solution be removed. 3. Verfahren zur Herstellung des wässerigen, kerami schen Titandioxidanstrichs nach Anspruch 1, umfassend Unter ziehen einer wässerigen Lösung eines Titansalzes mindestens einer Behandlung, ausgewählt aus der Gruppe, bestehend aus: (a) einer Dialysebehandlung unter Verwendung einer semipermeablen Membran,(b) einer Elektrodialysebehandlung unter Verwendung einer semipermeablen Membran, und(c) einer Ionenaustauschbehandlung unter Verwendung eines Ionenaustauschers, um zumindest einen Teil des Titansalzes zu Orthotitansäure und den kolloidalen, kristal linen Titandioxidteilchen zu hydrolysieren und umzuwandeln, wobei Verunreinigungsionen aus der wässerigen Titansalzlösung entfernt werden. 4. Verfahren nach Anspruch 3, wobei die Behandlungen (a), (b) und (c) bei einer Temperatur von 0 bis 80°C ausgeführt werden.
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4. The method of claim 3, wherein the treatments (A), (b) and (c) being at a temperature of 0 to 80 ° C are leading. 4. Verfahren nach Anspruch 3, wobei die Behandlungen (a), (b) und (c) bei einer Temperatur von 0 bis 80°C ausge führt werden. 5. Verfahren nach Anspruch 4, wobei die wässerige Lösung des Titansalzes auf eine Temperatur von 50°C oder mehr, jedoch weniger als 100°C, erwärmt wird und dann zumindest einer Behandlung, ausgewählt aus den Behandlungen (a), (b) und (c), unterzogen wird.
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5. The method according to claim 4, wherein the aqueous solu solution of the titanium salt to a temperature of 50 ° C or more, but less than 100 ° C, is heated and then at least ei ner treatment selected from the treatments (a), (b) and (C), is subjected. 5. Verfahren nach Anspruch 4, wobei die wässerige Lö sung des Titansalzes auf eine Temperatur von 50°C oder mehr, jedoch weniger als 100°C, erwärmt wird und dann zumindest ei ner Behandlung, ausgewählt aus den Behandlungen (a), (b) und (c), unterzogen wird. 6. Verfahren nach Anspruch 3 oder 5, wobei die wässerige Titansalzlösung eine wässerige Lösung ist, die mindestens ein Mitglied, ausgewählt aus der Gruppe, bestehend aus Titanoxychlorid und Titanoxysulfat, enthält.
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6. The method according to claim 3 or 5, wherein the wässe engined titanium salt solution is an aqueous solution, which minde least one member selected from the group consisting of Titanium oxychloride and titanium oxysulfate contains. 6. Verfahren nach Anspruch 3 oder 5, wobei die wässe rige Titansalzlösung eine wässerige Lösung ist, die minde stens ein Mitglied, ausgewählt aus der Gruppe, bestehend aus Titanoxychlorid und Titanoxysulfat, enthält. 7. Verfahren nach Anspruch 3, wobei die wässerige Titansalzlösung mit mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Alkalimetallhydroxiden und Ammoniak, in einer Menge von weniger als 4 Mol pro Mol Titan, das in der wässerigen Titansalzlösung vorliegt, vermischt wird und die erhaltene vermischte wässerige Lösung auf eine Temperatur von 50°C oder mehr, jedoch weniger als 100°C, erwärmt wird und dann mindestens einer Behandlung, ausgewählt aus den Behandlungen (a), (b) und (c), unterzogen wird.
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7. The method according to claim 3, wherein the aqueous Titanium salt solution with at least one member selected from the group consisting of alkali and Ammo monia, in an amount of less than 4 moles per mole of titanium, the is present in the aqueous titanium salt solution, mixed and the resultant mixed aqueous solution at a Tempe temperature of 50 ° C or more but less than 100 ° C is heated, is and then at least one treatment selected from the Treatments (a), (b) and (c), is subjected. 7. Verfahren nach Anspruch 3, wobei die wässerige Titansalzlösung mit mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Alkalimetallhydroxiden und Ammo niak, in einer Menge von weniger als 4 Mol pro Mol Titan, das in der wässerigen Titansalzlösung vorliegt, vermischt wird und die erhaltene vermischte wässerige Lösung auf eine Tempe ratur von 50°C oder mehr, jedoch weniger als 100°C, erwärmt wird und dann mindestens einer Behandlung, ausgewählt aus den Behandlungen (a), (b) und (c), unterzogen wird. 8. Verfahren zur Herstellung des keramischen Titandioxidanstrichs nach Anspruch 1, umfassend die Schritte:Vermischen einer wässerigen Lösung eines Titansalzes mit mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Alkalimetallhydroxiden und Ammoniak, in einer Menge von weniger als 4 Mol pro Mol Titan, das in der wässerigen Titansalzlösung vorliegt;und Erwärmen der erhaltenen vermischten wässerigen Lösung auf eine Temperatur von 50°C oder mehr, jedoch weniger als 100°C, um zumindest einen Teil des Titansalzes zu Orthotitansäure und den kolloidalen, kristallinen Titandioxidteilchen zu hydrolysieren und umzuwandeln;und Vermischen der erhaltenen kolloidale Titandioxidteilchen enthaltenden, wässerigen Lösung mit mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Alkalimetallhydroxiden und Ammoniak, zur Bildung eines Niederschlags;Abtrennung des erhaltenen Niederschlags von der wässerigen Lösung;und Dispergieren des abgetrennten Niederschlags in einem Dispergiermedium, das aus mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Wasser, wässerigen Lösungen von Peroxidverbindungen und wässerigen Lösungen von Titan-komplexierenden Mitteln, besteht.
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8. A method for producing ceramic Titandi oxidanstrichs according to claim 1, comprising the steps of:Mixing an aqueous solution of a titanium salt with at least one member selected from the group be Standing from alkali metal hydroxides and ammonia, in a Amount of less than 4 moles per mole of titanium in the wässe engined titanium salt solution is present;andHeating the resulting mixed aqueous solution to a temperature of 50 ° C or more, but less than 100 ° C, to at least a portion of the titanium salt to orthotitanic acid and the colloidal crystalline titania hydrolyze and convert;and Mixing the resultant colloidal titanium dioxide Part containing chen, aqueous solution with at least one Member selected from the group consisting of Alkalime hydroxides and ammonia to form a precipitate;Separating the resulting precipitate from the aq serigen solution;andDispersing the separated precipitate in a Dispersing medium from at least one member out selected from the group consisting of water, aqueous solu gene of peroxide compounds and aqueous solutions of Ti tan-complexing agents consists. 8. Verfahren zur Herstellung des keramischen Titandi oxidanstrichs nach Anspruch 1, umfassend die Schritte: Vermischen einer wässerigen Lösung eines Titansalzes mit mindestens einem Mitglied, ausgewählt aus der Gruppe, be stehend aus Alkalimetallhydroxiden und Ammoniak, in einer Menge von weniger als 4 Mol pro Mol Titan, das in der wässe rigen Titansalzlösung vorliegt;und Erwärmen der erhaltenen vermischten wässerigen Lösung auf eine Temperatur von 50°C oder mehr, jedoch weniger als 100°C, um zumindest einen Teil des Titansalzes zu Orthotitan säure und den kolloidalen, kristallinen Titandioxidteilchen zu hydrolysieren und umzuwandeln;und Vermischen der erhaltenen kolloidale Titandioxidteil chen enthaltenden, wässerigen Lösung mit mindestens einem Mitglied, ausgewählt aus der Gruppe, bestehend aus Alkalime tallhydroxiden und Ammoniak, zur Bildung eines Niederschlags;Abtrennung des erhaltenen Niederschlags von der wäs serigen Lösung;und Dispergieren des abgetrennten Niederschlags in einem Dispergiermedium, das aus mindestens einem Mitglied, ausge wählt aus der Gruppe, bestehend aus Wasser, wässerigen Lösun gen von Peroxidverbindungen und wässerigen Lösungen von Ti tan-komplexierenden Mitteln, besteht.

Independent claims9

185 paragraphs in 4 sections, as filed

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a ceramic Titanium dioxide coating, the coating of the glass, metal, Ceramics and plastics materials are suitable, and methods thereof for the manufacture.

In particular, the present invention relates to a for producing a paint coating having been draw ter hydrophilicity, photocatalytic activity and light permeability suitable ceramic titanium dioxide paint and methods for producing the same.

2. Description of the Prior Art

Compared with conventional organic coatings exhibit numerous paintings, the alkali metal silicates, phosphates, Silica and / or metal oxides, as kera mix paints known excellent heat resistance resistance and abrasion resistance.

Conventional ceramic coatings are out due recorded heat resistance and abrasion resistance over conventional inorganic coatings similarly advantageous. Since youngest attempt is made, the various ceramic paint coating by using ferent metal oxides as main components to new functions to lend.

Of the various metal oxides is known that Titania high hydrophilicity, similar to that of conventional ceramic materials such as silicon dioxide has. If the ceramic titanium dioxide coating on surfaces of ribs Heat exchangers is applied, contributes to the high Hydrophili capacity of the resultant coating to reduce the brid kenbildungsphänomens of condensed water between the Ribs, for preventing splashing of water drops and to increase the efficiency of the heat exchanger at. Although the ceramic titanium dioxide coating on a top surface of a transparent object, for example, of a glass article, is applied, the obtained hydrophilic ceramic coating accumulating Feuch activity on the surface of the object and tarnishing and prevent smearing of the surface.

Among the various ceramic coatings can Titanium dioxide paint films with excellent photokatalyti forming shear type and can under irradiation by Ul traviolettstrahlen exhibit high oxidative effect. the According, it is known that after application of the ceramic Titanium dioxide paint to a surface of a metal, glass or Ceramic article the paint coating obtained better usability against pollution, promoting Decomposition of malodor-generating materials, Purifying water, corrosion prevention, anti microbial ler treatment, prevention of proliferation of algae and Zer tion of substances which decompose difficult having. Therefore Various attempts have been made to Titandioxidan strokes to form a titanium dioxide coating on top surfaces of articles and process for preparing the provide titanium dioxide coatings.

As a method for producing a Titandioxidan dot coating is a sol-gel coating method, where a hydrolysis product of a titanium alkoxide as an essential used Liche component of the paint, known. As Analogous method to the sol-gel method teaches the Japanese Unexamined Patent Publication no. 4-83537 manufacturing a titanium dioxide paint by adding an amide or Gly colverbindung to a titanium alkoxide. The Japanese Unexamined te patent publication no. 7-100378 discloses also a process for producing a titanium dioxide paint by addition of alcohol to amine is a titanium alkoxide.

Further, Japanese Unexamined Patent discloses publication no. 6-293519 a process for preparing a paint coating, titanium dioxide fine particles, through crystal growth by a treatment in hot water at a temperature of 100 ° C or more using a dispersant are dispersed and the resulting Dispersion is applied and a further coating method in which a binder, such as water glass, colloidal silica or fluorine resin, with kristal linen titanium dioxide is mixed and the resultant is applied mixture.

The sol-gel method is disadvantageous because (1) an acid used as a hydrolysis agent and as to rate used amine or glycol usually get in NEN paint coating remain so for their Entfer opening the paint coating obtained at a high Tem temperature should be burned, (2) the obtained Titandi oxidanstrichbeschichtung a high amount of combustible orga tronic solvent containing and (3) the starting materials are costly.

The above-mentioned coating method for a titanium dioxide coating, wherein the titanium dioxide crystals are grown at a temperature of 100 ° C or more, is disadvantageous because (1) the coating obtained an un having a low level of transparency and thus not for transparent objects, such as glassware, is suitable, and (2) is applied to ribs of Wärmetau will exchangers of titanium dioxide coating with a low Fixie tion efficiency detained and the coated fins generate a specific, for ceramic materials ei genartigen smell.

The conventional coating method for Titandioxidan dash, a resin as a binder for titanium dioxide Part Chen is used, is also disadvantageous because, (1) Although the resin coating to increase the self- properties, adhesion and fixation efficiency the resulting paint contributes to Anstrichbe obtained coating when using an insufficient durability comprising, as the resin by the photocatalytic action of Titanium dioxide is reduced, and (2) the addition of the resin reduced proportion of titanium dioxide and thus the ads received dot coating an insufficient hydrophilicity and having photocatalytic activity.

SUMMARY OF THE INVENTION

Object of the present invention, the Ready provision of a hydrophilic photocatalytic and light permeable ceramic titanium dioxide paint, of the we sentlichen not for the photocatalytic action of the titanium dioxide harmful impurities and no organic Materials, such as alcohols having, and ke can form ramische paint coating, the excellent Hydrophilicity and photocatalytic activity light permeability and adhesive strength has, and a process for Her position thereof.

The foregoing object is achieved by the erfindungsge Maessen aqueous ceramic titanium coating for the manufacture ment of a paint coating with excellent Hydrophi lizität, photocatalytic activity and Transparent dissolved speed, comprising:

<ul><li>(A) at least one member selected from the Grup group consisting of orthotitanic acid, titanium (IV) ions and by oxotitansäure, and</li><li>(B) colloidal crystalline titanium dioxide particles with an average particle size of 0.001 to 0.2 microns,</li></ul>

wherein the weight ratio of component (A) to Component (B), based on titanium, 1: 0.1 to 1: 200, and the ceramic paint substantially no contami supply versions contain.

The above-mentioned aqueous ceramic Titandi oxidanstrich can be prepared by the method (1) of the present Invention are prepared, comprising subjecting a aqueous titanium salt solution at least one treatment of selected from the group consisting of:

<ul><li>(A) of a dialysis treatment using a semi-permeable membrane,</li><li>(B) an electrodialysis treatment using a semipermeable membrane, and </li><li>(C) an ion-exchange treatment using an ion exchanger, at least a portion of the titanium salt to orthotitanic acid and the colloidal crystalline Titanium dioxide to hydrolyze and convert, wherein Impurity ions from the aqueous titanium salt solution ent removed be.</li></ul>

In one embodiment of the present invention is the aqueous solution of the titanium salt prior to the at least a treatment selected from treatment (a), (b) and (C) to a temperature of 50 ° C or more but less than 100 ° C, heated.

In a further embodiment of the inventive KISSING procedure is before the at least one treatment, from treatments selected from (a), (b) and (c), the aqueous Ti tansalzlösung with at least one member selected from the group consisting of alkali and Ammo monia, in an amount of less than 4 moles per mole of titanium, the is present in the aqueous titanium salt solution, mixed, and the obtained mixed aqueous solution to a temperature of 50 ° C or more but less than 100 ° C, heated.

The above-mentioned aqueous, ceramic titanium dioxidanstrich can also by the method (2) of the vorlie lowing invention are prepared, comprising the steps of:Mixing an aqueous solution of a titanium salt with at least one member selected from the group be Standing from alkali metal hydroxides and ammonia, in a Amount of less than 4 moles per mole of titanium in the wässe engined titanium salt solution is present; andHeating the resulting mixed aqueous solution to a temperature of 50 ° C or more, but less than 100 ° C, to at least a portion of the titanium salt to orthotitanic acid and the colloidal crystalline titania hydrolyze and convert; andMixing the resultant colloidal titanium dioxide Part containing chen, aqueous solution with at least one Member selected from the group consisting of Alkalime hydroxides and ammonia to form a precipitate; Separation ( "collecting") of the obtained precipitate from the aq serigen solution; andDispersing the separated precipitate in a Dispersing medium from at least one member out selected from the group consisting of water, aqueous solu solutions of peroxide compounds and aqueous solutions of Titanium complexing agents consists.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The inventive aqueous ceramic Titandi oxidanstrich to form a hydrophilic, photokatalyti rule and translucent paint coating contains (A) at least one member selected from ortho titanic acid, Ti tan (IV) ions and peroxotitanic acid, and (B) crystalline kol loidale titanium dioxide particles having an average particle size from 0.001 to 0.2 microns (1 to 200 nm).

The usable for the present invention Ortho titanic acid exhibits a high solubility in acidic aqueous Solutions, and substantially no crystallizability and can therefore clearly un of crystalline titanium dioxide be distinguished. The ver in the present invention reversible titanium dioxide also include Metatitansäure-, Anatase titanium dioxide and rutile titanium dioxide a.

can In the ceramic coating according to the invention the ortho titanic acid as a precipitate by adding at least one member selected from alkali metal hydroxides, in for example sodium hydroxide, and ammonia to a Wässeri gen solution of at least one water-soluble titanium compound, For example, titanium tetrachloride, titanium sulfate, Titanoxychlo chloride or titanium oxysulfate manufactured. The resulting Orthotitanium acid precipitate is separated by filtration and rinsed with water. The separated titanic acid can be used as Material for the ceramic coating according to the invention a are set.

The ceramic for the inventive paint usable peroxotitanic, by adding a Wässeri gen peroxide solution to an aqueous solution of Orthotitanic acid, prepared by the above-mentioned Method, be prepared as an aqueous solution.

Additionally Kerami the invention for the rule paint used titanium (IV) (Ti<sup>4+</sup>) Ions through on solve a water-soluble titanium salt in water produced be and fed. In particular, the titanium (IV) ions in an acidic aqueous solution having a pH value of 3 or less stable present. Preferably at the Titanium (IV) ions in the form of an organic or inorganic Kom plex before.

The inventive ceramic titanium dioxide paint must in addition to the orthotitanic acid, titanium (IV) ions and / or the peroxotitanic the crystalline Titandi oxide particles comprise. The crystal form of the titanium dioxide part chen is preferably Anastas and further preferably Ru til.

The crystalline titanium dioxide particles have a average particle size of 0.001 to 0.2 microns, more preferably 0.002 to 0.1 .mu.m, in particular from 0.002 to 0.07 .mu.m. If the average particle size is less than 0.001 microns, is the resultant titanium dioxide paint coating in the Hydro philizität and photocatalytic activity unbefriedi quietly. If the average particle size is more than 0.2 micron, shows the titanium dioxide paint coating obtained unzurei sponding hydrophilicity, light transmittance and unzureichen the adhesion to a substrate surface. If the mitt is sized particle size ranging from 0.002 to 0.1 microns, can ceramic titanium dioxide paint coating obtained from Show subscribed hydrophilicity.

In the ceramic Titandioxidan invention dash, the weight ratio of component (A), the of at least one member selected from orthotitanium acid, titanium (IV) ions and peroxotitanic acid is, for Component (B), with the titanium dioxide particles of crystalline an average particle size of 0.001 to 0.2 microns, preferably , 0.002 to 0.1 micron, is, in the range 1: 0.1 to 1 in 200. If the weight ratio is less than 1: 200, that is, when the proportion of component (A) is too low and the on part is too high in component (B) shows the obtained at underlined insufficient hydrophilicity, adhesion to the sub stratoberfläche and light transmittance (transmittance). If the weight ratio is more than 1: that is, if 0.1 the proportion of component (B) is too low, showing the sustainer tene paint coating insufficient hydrophilicity and photocatalytic activity.

The inventive ceramic titanium dioxide paint can at least ei by mixing an aqueous solution nes member selected from ortho titanic acid, titanium (IV) -Io NEN and peroxotitanic, with titanium dioxide or titanium dioxidteilchen containing sol or by hydrolysis and order convert at least a portion of a titanium salt, dissolved in Water to ortho titanic acid and titanium dioxide and, where appropriate, converting at least a portion of the orthotitanic acid are prepared to peroxotitanic.

The aqueous solution of orthotitanic acid, titanium (IV) ions and peroxotitanic can by adding an aqueous alkaline solution to an aqueous solution of an OR thotitansalz to prepare a precipitate from Ortho titanium acid, separating the ortho titanic acid precipitate and Dispersing the separated ortho titanic acid precipitate in an aqueous dispersing medium which consists of water, a aqueous solution of a peroxide compound and / or an aq serigen solution of a titanium-complexing agent is, getting produced.

The ortho titanic acid and titanium dioxide contained tend inventive aqueous paint may it through the inventive method are prepared, in which a aqueous solution of a titanium salt a hydrolysis is subjected to at least a portion of the titanium salt is hydrolyzed and ortho titanic acid and the crystalline NEN, colloidal titanium dioxide particles which have an average part comprise-size in from 0.001 to 0.1 microns, is converted.

Also, the peroxotitanic and Titandi oxide particles containing aqueous coating according to the invention by addition of peroxide, for example, water peroxide, prior to the aqueous orthotitanium saline or be prepared by the hydrolysis. In this Case, the amount of peroxotitanic acid in the obtained aqueous coating by controlling the amount of to the aqueous titanium salt solution to be added to peroxide 0 to 100% can be set. That is, when no peroxide compound is added, which contains the aqueous obtained Painting orthotitanium acid and no peroxotitanic. If the but peroxide compound in an amount equal to or more than the molar amount of the orthotitanic acid is added contains the resulting aqueous paint peroxotitanic and no Orthotitanium acid.

If the pH of the reaction system is low, for example, 2 or less, a part of the orthotitanic acid to titanium (IV) ions converted. In this case, for Stabilization of the resulting aqueous liquid Virtue as a complexing agent for aqueous liquid ge type, thereby the titanium (IV) ions to a titanium (IV) -COM implement complex and a stabilized aqueous On dash to get.

The ver the formation of tetravalent titanium complex reversible complexing agent preferably comprises at least a member selected from lactic acid, oxalic acid, formic acid and acetyl acetone. Gluconic acid, tartaric acid, acetic acid, Malic acid, succinic acid and EDTA (Ethylendiamintetraes sigsäure) can also be used as complexing agents for titanium be used.

To the aqueous solution of orthotitanic acid, Ti to be added tan (IV) ions and / or peroxotitanic Titandi can oxide particles in the form of solid particles or as aq seriges Sol present. When the titanium dioxide in the form of aq serigen particles is added, the resulting mixture is preferably, for example, using a homomixer fully stirred, to titanium dioxide particles uniformly disperse and the formation of agglomerated particles to prevent. A dispersant such as a Ten sid contains, can in small amounts to the dispersion system are added to the dispersion of titanium dioxide drive.

In the process for producing the aqueous ke ramischen titanium dioxide paint is used as a raw material suitable titanium salt, preferably titanium chloride, Titansul fat, titanium oxysulfate and titanium oxychloride selected. More water-soluble inorganic titanium salts and water-soluble or ganic titanium salts, for example, oxalate and Ti tancitrat, have the titanium salt for invention Methods are used.

The aqueous titanium salt solution is prepared by dissolving egg nes titanium salt are prepared in water or can of commercial dilute aqueous titanium salt solutions to get voted.

If anhydrous titanium chloride as the starting material is used, by an aqueous titanium chloride solution gradually dissolving anhydrous titanium chloride in pure Water are produced under ice cooling. Although Titan trichloride is used as the starting material, are first Titanium (III) ions to titanium (IV) ions with a Oxidationsmit tel, for example with hydrogen peroxide, oxidized and there to the resulting titanium tetrachloride to aqueous paint generating process undergone.

An aqueous titanium sulfate solution is a 30% aq serige solution commercially available and so can the commercial Solution for the inventive method, after appropriate Dilution used.

An aqueous titanium oxychloride or Titanoxysulfat- solution can be prepared by an aqueous solution anionization of titanium sulfate or titanium chloride through a Anionenentfer recognition methods such as an ion exchange membrane or an Io nenaustauscherharz or by dissolving hydrated Ti dioxide are produced in sulfuric or hydrochloric acid.

In the method (1) of the present invention the aqueous titanium salt solution for the hydrolysis Titanium salt subjected including (1) at least one of Treatments selected from:

<ul><li>(A) of a dialysis treatment using a semi-permeable membrane, </li><li>(B) an electrodialysis treatment using a semipermeable membrane, and</li><li>(C) an ion-exchange treatment using an ion exchanger and, where appropriate, the above said treatment, (2) a heat treatment at a Temperature of 50 ° C or more but less than 100 ° C, for the aqueous titanium salt solution or (3) a combination of (I) an alkali treatment by mixing at least one Member selected from alkali metal and ammonium ak, in an amount of less than 4 moles per mole of titanium, the is present in the aqueous titanium salt solution, in the aqueous Titanium salt solution with (ii) a heat treatment at a Tem temperature of 50 ° C or more but less than 100 ° C, for mixed aqueous solution, thereby at least one part the titanium salt to the orthotitanic acid and the colloidal crystalline titanium dioxide particles having an average part to hydrolyze-size in from 0.001 to 0.2 microns and umzuwan spindles. During the treatment (a), (b) and / or (c) Impurity ions from the aqueous titanium salt solution ent removed.</li></ul>

The optionally applied treatments (2) and (3) submit to promote the hydrolysis of titanium salt Treatment (a), (b) and / or (c) and to increase the effect to remove impurity ions in the treatment (A), (b) and / or (c).

In the inventive method (2) for the manufacture ment of the aqueous ceramic titanium dioxide paint is an aqueous solution of a titanium salt with at least one Member selected from the group consisting of Alkalime hydroxides and ammonia, in an amount of less than 4 Moles per mole of titanium present in the aqueous titanium salt solution is mixed; and the resultant mixed aqueous solu solution is heated to a temperature of 50 ° C or more but we niger than 100 ° C, heated to thereby at least one part the titanium salt to the orthotitanic acid and the colloidal hydrolyze crystalline titanium dioxide and convert convert, and then the colloidal titanium dioxide particles obtained aqueous solution containing at least one member, selected from the group consisting of Alkalimetallhydroxi and the ammonia, mixed to form a precipitate andthe resulting precipitate is removed from the aqueous separated solution to form a substantially no Verun cleaning emissions containing precipitate provided is, and finallyis the separated precipitate ( "collected percipitate") in a disper greed medium, consisting of one member selected from the Group consisting of water, aqueous solutions of Per oxide compounds and aqueous solutions of titanium complexation -generating agents, dispersed.

In the methods (1) and (2) of the present inventions tion, the hydrolysis to be exposed to aqueous Titanium salt solution preferably has a titanium concentration of 0.1 to 10 weight percent, more preferably 0.5 to 4 Gewichtspro centered on.

If the concentration of titanium is less than 0.1 weight is percent, the aqueous paint obtained can not make paint coating having a desired thickness. If the titanium concentration is more than 10 weight percent, , the aqueous titanium salt solution during the Ver unreinigungsionen removing treatment (a), (b) and / or (C) in the method (1) gel.

In the method (1) of the present invention each of the treatments (a), (b) and (c) preferably at a Temperature of 0 ° C to 80 ° C, more preferably 10 to 50 ° C out, leads. During this treatment at least a portion hydrolysed the titanium salt in the aqueous titanium salt solution Siert and ortho titanic acid and crystalline Titandi oxide particles converted.

When the titanium salt is selected from titanium tetrachloride (TiCl₄) be is that hydrolysis of titanium salt during treatment is treatment (a), (b) and / or (c) according to the following reactions executed.

The by-product of reactions (1) and (2) (namely, HCl) is the same with the impurity ions by the treatment (a), (b) and / or (c) from the reactivated onsgemisch away.

When the hydrolysis of the titanium salt during treatment treatment (a), (b) and / or (c) according to the invention The method is executed, the orthotitanic acid is incurred in a relatively high proportion and the Sustainer requested titanium dioxide particles have a very small particles size and thus shows the paint coating obtained an increased mechanical strength.

Preferably, the aqueous titanium salt solution, undergo the process of the invention the (1) should, at least one member selected from titanium oxychloride and oxysulfate.

In the method (1) of the present invention treating (a) a diffusion dialysis treatment Using a semipermeable membrane and a diffusion medium consisting of water, preferably pure water. The semipermeable membrane for the treatment (a) usable can be prepared from anion exchange membranes, diaphragms, the so well let pass anions and cations in example RO membranes, cellophane (regenerated selected cellulose) membranes, bladder membranes and collodion membranes will. Cation can impurity ions such as Cl⁻ and SO₄<sup>2-</sup>But hardly remove and thus is a semipermeable membrane consisting only of a cation exchanger exchange membrane is, for the present invention not be preferred. However, the cation can in Kombi nation with an anion exchange membrane to form a semipermeable membrane are applied.

The diffusion dialysis treatment (a) is preferably for a period of one hour or more, more preferably, if possible, carried out 3 hours or more.

The extent of progress of the diffusion dialysis can by the pH value or the electric conductivity of the Dialysis fluid are detected. That is the Diffu sion dialysis treatment (a) is preferably continued until increases the pH of the dialysis fluid and a measure of 2 to 7 is reached or until the electrical conductivity of the Dialysis fluid decreases and a level of 1 mS / cm or less reached. The aqueous paint obtained can however Cl⁻ ion contained in an amount of about 1 g / liter or less th to the storage stability of orthotitanic acid and the Titanium dioxide to increase.

The treatment (b), the Ver invention for the drive (1) is appropriate, is an electrodialysis treatment using a semipermeable membrane, preferably an anion exchange membrane. Compared with the diffusi onsdialysebehandlung (a), the electrodialysis treatment (b) advantageous in that the treatment in a relatively short Time can be terminated.

The electrodialysis using a Anionenaus exchange membrane is carried out in an electrolysis vessel, the with an anode plate and a cathode plate, the par allele are arranged to each other, and by a Anionenaus exchange membrane separated the anode and parallel to the Ka method plates to form an anode and a cathode chamber is arranged. In the anode chamber, the aqueous filled titanium salt solution and the cathode chamber is What these contain.

The cathode plate is preferably a platinum plate, a platinum-coated titanium plate or DSE (a insoluble cathode). The anode is preferably made of a platinum coated titanium plate or a stainless steel plate made.

In the electrodialysis treatment (b) is an elec tric power, preferably with a current density of 0.01 to 10 A / dm² is applied. If the current density is more than 10 A / dm² is the problem that colloidal particles can appear, attached to the semipermeable membrane. The for treat- ment (b) suitable anion exchange membrane is preferably from strong base anion exchange, preferably selected with a resistance to acids.

In the method (1) of the present invention is the ion exchange treatment (c) preferably USAGE formation of an anion exchanger, preferably a Anionenaus exchange resin is carried out. The anion exchanger can be made of Zeolite, basic muscovite, hydrated iron oxide and hy dratisiertem zirconia that Anionenaustauscheraktivität have to be selected.

In the ion exchange treatment (c), the Kon Diplomatic the aqueous titanium salt solution with the ion exchanger by directly mixing an ion exchanger in the aq serige titanium salt solution or by passing the aqueous Ti tansalzlösung through a column filled with ion exchange column be effected.

The extent to which progresses the ion exchange, , by controlling the pH value or electrical Leit ability of the obtained treatment liquid for a be voted growing value or a certain sloping Value can be controlled.

During the above treatment (a), (b) and / or (c) is at least a portion of the titanium salt in the hydrolyzed aqueous solution thereof and ortho titanic acid converted and titanium dioxide particles, and are simultaneously the present in the aqueous liquid contami supply versions removed. The aqueous paint obtained is because forth substantially free of impurity ions, Example as anions such as Cl⁻ and SO₄<sup>2-</sup>And cations such as Na⁺.

If the removal of impurity ions through a conventional method, for example by filtration of the aqueous paint through a microfilter or ultrafilter and then executed rinsing the filter with water, is, the orthotitanic acid, titanium (IV) ions and / or Peroxotitanic together with the impurity ions from the aqueous coating removed, thus indicating the Sustainer tene paint coating insufficient transparency (Light transmittance) and unsatisfactory adhesion.

In one embodiment of the method (1) before the invention is prior to the treatment (a), (b) and (c) an aqueous solution containing titanium salt is, for example, Ti tanchlorid, titanium sulfate, titanium oxysulfate or titanium oxychloride, contains, to a temperature of 50 ° C or more but Weni ger than 100 ° C, preferably 60 to 90 ° C, heated to the Hy advancing ysis of the titanium salt. Heat treatment contributes to increasing the share of the resulting Titandi oxide particles and to control the particle size of the receive NEN titanium dioxide at a desired value. This means the heat treatment contributes to the resultant dot coating the desired level of photocatalytic having activity.

When the temperature during the heating is less than 50 ° C is that titanium dioxide can be difficult with a desired particle size are produced and thus can The photocatalytic activity of the obtained Anstrichbe coating does not achieve the desired level. Even though the Heating temperature 100 ° C or more, can the Sustainer tene aqueous paint in a larger amount coarse titanium dioxide particles contained and thus a low Lagerungssta stability due to the precipitation of coarse titanium dioxide Part chen included and the paint coating obtained may have insufficient transparency.

The heat treatment is preferably 3-240 running minutes. If the heat treatment at a rela tively low temperature is carried out, for example, 30 to 60 ° C, has the initial aqueous titanium salt solution a relatively high pH, for example, 3 to 7, to and the heating time may be more than 240 minutes.

Preferably, the heat treatment is total uniform heating of the aqueous titanium salt solution is contained in a reactor, by using a Heat exchanger from the hot water type or a hot water bath carried out while uniformly stirred. A local Heating the aqueous titanium salt solution, for example by an immersion heater, should be avoided. To the formation and the growth of the titanium dioxide particles in the heat treat to control treatment, is preferably a part of titanium dioxide chen existing nucleating agent for colloidal Ti tandioxidteilchen or an aqueous dispersion of Keimbil tion agent, preferably in a small amount of aq serigen titanium salt solution is added. After the heat treat action is the titanium dioxide containing preserved Liquid or preferably to a temperature of 40 ° C less cooled by a water cooler and then the above treatment (a), (b) and / or (c) under coated, wherein the hydrolysis of titanium salt remaining wei ter is driven while Verunreinigungsan ion, such as Cl⁻ and SO₄<sup>2-</sup>And Verunreinigungskat ion, such as Na +, the ions consisting of Ti tan, oxygen and / or hydrogen are different, ENT removed be.

In a further embodiment of the method (1) of the present invention is an aqueous solution of Titanium salt with at least one member selected from the Group consisting of alkali metal hydroxides and ammonia, in an amount of less than 4 mol, preferably 0.1 mol or more but less than 4 moles per mole of titanium in the aq serigen titanium salt solution is present, mixed, and the resultant mixed aqueous solution is at a temperature of 50 ° C or more but less than 100 ° C, heated and then treat- Lungs (a), (b) and / or (c) subjected.

More preferably, the total amount of alkali metal hydrosulfide dioxide and / or ammonia 0.5 mol or more but less than 3 Moles per mole of the titanium contained in the starting solution.

When the amount of alkali metal hydroxide and / or ammonium niak 4 moles or more per mole of titanium in the starting solution exists, is that titanium dioxide particles obtained can at the heat treatment and in the treatment (a), (b) and / or (C) do not grow to the desired particle size. Also when the amount of alkali metal hydroxide and / or ammonia we niger than 0.1 moles per mole of titanium by weight, the heat treat can treatment and the treatment (a), (b) and / or (c) growth of titanium dioxide particles in a too large particle size ver causes.

The alkali metal hydroxide and / or ammonia before preferably in the state of a dilute aqueous solution a concentration of 2 to 10 weight percent to the aq given serigen titanium salt solution.

Subsequently, the alkali and / or ammonia mixed solution de rselben heat treatment as above subjected described. The mixed solution has preference , a titanium concentration of 0.1 to 10 weight percent, more preferably 0.5 to 4 weight percent, on. If the titanium concentration is less than 0.1 weight percent, can it be difficult to get a paint coating with a Dic to obtain ke, the suffi for the desired properties is accordingly. If the concentration of titanium greater than 10 weight is percent, the resulting liquid can after Heat treatment during the treatment (a), (b) and / or (c) gel.

The heat treatment for the alkali and / or ammonium ak-mixed aqueous titanium salt solution is under the same Conditions performed as mentioned above, ie, at a Temperature of 50 ° C or more but less than 100 ° C.

After completion of the heat treatment is heated Liquid or preferably to a temperature of 40 ° C less cooled, and then the treatment (a), (b) and / or (c) subjected. During the above-mentioned alkali and / or Ammonia admixture and the heat treatments and the treatment treatment (a), (b) and / or (c) is at least a portion of the titanium salt hydrolyzed and ortho titanic acid and titanium dioxide converted particles and during the treatment (a), (b) and (C) the impurity ions from the aqueous liq fluid containing afford a titanium dioxide aqueous ceramic paint removed.

The combination of alkali and / or ammonia Vermi research treatment and heat treatment has a beneficial way, since the hydrolysis and the conversion of the titanium salt to Ortho titanic acid and titanium dioxide is promoted and the resulting paint excellent improved Hydrophili capacity, photocatalytic action and better adhesion shows.

In the method (2) of the present invention the aqueous titanium salt solution of the same combination of Alka li- and / or ammonia Anmischbehandlung with the above subjected to said heat treatment to at least a portion the titanium salt to orthotitanium acid and titanium dioxide with a mean particle size of 0.001 to 0.2 microns to hy drolysieren and convert. The resultant aqueous solution, containing ortho titanic acid and titanium dioxide, is then with at least one member selected from Alkalime hydroxides and ammonia, ver to form a precipitate mixed. The precipitate is separated from the solution and optionally rinsed with water. The separated low impact is dispersed in an aqueous dispersion, at least one member selected from water, Wässeri gen solutions of peroxide compounds and aqueous solutions of titanium complexing agents contains.

By separating and optionally rinsing with water the precipitate obtained is substantially free of Ver unreinigungsionen. Accordingly, in the method, (2) the present invention, the above-mentioned treatment (A), (b) and / or (c) can be omitted. The separation of the Precipitate is by filtration or Zentrifugalabtren tion causes.

is in the dispersion of the separated precipitate the peroxide compound is preferably selected from water peroxide, sodium peroxide and barium peroxide. The peroxide compound reacts with at least a portion of the orthotitanic acid and titanium (IV) ions to form peroxotitanic. When hydrogen peroxide is used, the addition of can be hydrogen peroxide before separating the precipitate are leading. When sodium peroxide or barium peroxide USAGE det is, the aqueous paint obtained can moreover above-mentioned treatment (a), (b) and / or (c) under be subjected to sodium ions or barium ions from the wässe remove engined paint.

The complexing agent preferably comprises minde least one member selected from lactic acid, oxalic acid, Formic acid, acetylacetone, gluconic acid, tartaric acid, vinegar acid, malic acid, succinic acid and EDTA.

By the method (1) or (2) of the present Invention aqueous ceramic Titandioxidan produced in addition to ortho titanic acid, titanium (IV) ions contains dash and / or a high amount of peroxotitanic crystalline Ti tandioxidteilchen. Ordinarily, the titanium dioxide particles Anatase crystal form. Depending on the conditions However, the heat treatment, the titanium dioxide Ru Include til crystal particles.

The method in which, by (1) or method (2) of the produced the present invention, aqueous ceramic Painting titanium dioxide contained also exhibit Particle size within the range 10<sup>-3</sup> to 4 × 10<sup>-1</sup> microns and an average particle size of 0.001 to 0.2 microns, preferably as 0.002 to 0.1 .mu.m.

By the method (1) or (2) of the present Invention aqueous coating produced can with photokata lytic titanium dioxide or photocatalytic, kol loidalen titanium or a sol are mixed.

The aqueous ceramic titanium dioxide paint is also optionally with a coloring pigment, it to the preserved paint coating a desired color to ver borrow, or with at least one member selected from Materials based on ceramics such as abrasion solid oxide, nitride or carbide compounds to the Ver wear resistance of the coating to increase paint, or mixed with fine metal particles, fine example Zinc or aluminum particles to the corrosion resistance the paint coating to increase. The composition of the Paint Namely given the necessary egg set properties of the resultant paint coating will.

The inventive aqueous ceramic Titandi oxidanstrich is formed by applying the aqueous ceramic Paint on a surface of a substrate article, Drying the coated paint layer and bake the dried paint layer at a temperature of front preferably 100 to 700 ° C, preferably 200 to 500 ° C Herge, provides. Usually contains the branded An obtained dot coating anatase titanium dioxide crystals. When A burning at a temperature of 700 ° C or more, however, can at least a part of the anatase crystals to rutile crystals being transformed. The crystal transition does not cause Decrease or no loss of hydrophilicity of at dot coating.

If the aqueous ceramic paint to a Sub is applied stratoberfläche and dried, the obtained ceramic paint coating usually a Thickness of 0.05 to 1 microns. In this paint coating the crystalline titanium dioxide particles uniformly ver shares and colloidal or gelled orthotitanium acid or Per filled oxotitansäure or fills the interstices between the divided crystalline titanium dioxide. Also at Drying the paint coating at a relatively low Tempe temperature of 100 to 200 ° C, the colloidal or gelled Orthotitanic acid and / or dehydrated and peroxotitanic converted to hydrated titanium dioxide, the increased Surface and a high water content which, or Ti dioxide, so that the crystalline titanium dioxide fixed are joined together so that the paint coating strongly adheres to the substrate surface, so that the Hydrophili increasing capacity of the paint coating and so light preventing or reducing scattering at the particle surface becomes. The paint coating obtained is free of non photocatalytic binders and thus sufficiently photocatalytic activity, hydrophilicity and light have permeability.

In the methods (1) and (2) of the present inventions thereof for producing the aqueous titanium dioxide ceramic paint, fine particles of titanium dioxide with out draw ter hydrophilicity and photocatalytic activity Herge provides and by hydrolyzing a titanium salt in a aqueous medium under specific conditions to ge grow desired optimum particle size. Over the Unite drive (1) and (2) of the present invention are Kri stallkeimteilchen of hydrated titanium dioxide produced, when the aqueous titanium salt solution with alkali metal hydroxide and / or ammonium in an amount of less than 4 moles, before preferably 0.1 mol or even less than 4 moles per mole of titanium, contained in the aqueous titanium salt stock solution is mixed.

When the titanium dioxide crystals to form strong coarse particles grow, are alkaline ions in the large ben titanium dioxide introduced. The heat treatment makes for the prevention of excessive crystal growth and thus preventing the introduction of alkaline ions in the Crystals and for increasing the transparency and responsible hydrophilicity of the resultant paint coating literally.

If the aqueous ceramic titanium dioxide obtained painting impurity ions such as Cl⁻, SO₄<sup>2-</sup> and Na⁺ contains, shows by coating the aqueous On stroke on a substrate surface and drying the transmitted Coating obtained a paint coating insufficient transparency and is an uneven, white Coating. In addition, the paint coating is a insufficient photocatalytic activity. Therefore, this aqueous paint for coating a transparent Ge genstands, for example, a glass object, unsuitable.

In the method (1) of the present invention who the impurity ions from the aqueous paint by the specific treatment (a), (b) and / or (c), where hydrolyzing and converting at least a portion of Titanium salt to orthotitanium acid and crystalline Titandi oxide particles is carried out. Also in the method (2) of the present invention, the aqueous orthotitanic acid containing liquid and crystalline titanium dioxide with an alkali metal hydroxide and / or ammonia under Bil formation of a precipitate is mixed, the resultant low impact is separated and optionally rinsed with water and the separated precipitate, which is essentially free is impurity ions, in an aqueous Di spergiermedium selected from water, an aqueous solution of a Peroxide compound and / or an aqueous, a complexation tion medium containing solution is dispersed, under Providing an aqueous crystalline ceramic Ti tandioxidanstrichs which is substantially free of contami is supply versions.

Since the aqueous ceramic titanium dioxide paint the the present invention is substantially free of contami transmission versions, the paint coating exhibits in advantageously an excellent transparency, excellent adhesion, excellent hydrophilicity and photocatalytic activity.

For an article made of aluminum or copper, the should have a high hydrophilicity, for example, a fin material for heat exchanger, which can erfindungsge Permitted aqueous ceramic titanium dioxide paint a painting coating with excellent photocatalytic activity forming on the object and the object may increased Antifouling, deodorizing, anti-corrosion, anti-bacterial and impart anti-algae effects. The paint coating can in the course of time the reduction of the hydrophilicity and Generating malodor by bacterial growth in Water droplets that condense on the object surface, prevent. Since the aqueous from the titanium dioxide Keramikan underlined the present invention formed Anstrichbeschich device has a high transparency, the aqueous ceramic paint for coating transparent Articles, such as glass articles, suitable and thus has a high practical utility.

EXAMPLES

The present invention will be further by the Examples below explained.

Examples 1 to 4

In each of Examples 1 to 4 was an aqueous Paint by mixing an aqueous 10% Natriumhy hydroxide solution with an aqueous 5% Titantetrachloridlö solution to produce precipitate, separating the low proposal consisting of ortho titanic acid, by filtration, Rinsing the separated precipitate with water, Dispersin ren of the precipitate in water, mixing the resulting Or thotitansäure containing aqueous solution with crystalline Titanium dioxide particles and then mixing the resultant liq fluid with the complexing agent in the as shown in Table 1 amount specified in each Examples 1, 3 and 4 and with the aqueous hydrogen peroxide solution in sufficient Amount to the concentrator as shown in Table 1 in Example 2 tration to realize at peroxotitanic, and complete Stirring the resultant mixture liquid using a homomixer manufactured. The aforementioned kri talline titanium dioxide were under the trademark Titanium dioxide P-25 (anatase or rutile), manufactured by Nihon Aerosil KK available. The above complexation tion medium consisted of acetyl acetone in Example 1, milk acid in Example 3, and oxalic acid in Example 4. Fig.

Examples 5 and 6

In each of Examples 5 and 6 was an aqueous Paint prepared as follows.

An aqueous 10% titanium tetrachloride solution was with sodium hydroxide in an amount of 1 mole per mole of titanium, which was present in the titanium tetrachloride solution, mixed, the ge Mixed liquid was at a temperature of 90 ° C 40 heated minutes, the heated liquid with a aqueous 5% sodium hydroxide solution in such a Lot mixed, the mixed liquid obtained un ter forming a precipitate neutral was. The Sustainer tene ortho titanic acid and titanium dioxide comprehensive precipitation was dispersed in water. The aqueous disper obtained sion was in with an aqueous hydrogen peroxide solution such an amount blended that Mischflüs obtained fluid a concentration shown in Table 1 to Per oxotitansäure had. The resulting mixed liquid was fully stirred using a homomixer. On aqueous titanium dioxide ceramic paint was obtained.

As a result of analysis, it was confirmed that the obtained aqueous coating crystalline anatase Titandi oxide particles having an average particle size of 0.08 microns contained.

Examples 7 and 8

In each of Examples 7 and 8 was an aqueous Paint prepared as follows.

An aqueous 10% titanium tetrachloride solution was with sodium hydroxide in an amount of 2 moles per mole of titanium, which was present in the titanium tetrachloride solution, mixed. The mixed solution was for a temperature of 75 ° C 20 heated minutes. The heated liquid with a aqueous 5% sodium hydroxide solution in such a Lot mixed, the mixed liquid obtained became neutral to produce a precipitate. The he preserved ortho titanic acid and titanium dioxide comprehensive low impact was dispersed in water. The aqueous obtained Dispersion was in Example 7 with gluconic acid in an in Table 1 concentration and shown in Example 8 with a aqueous hydrogen peroxide solution in an amount such that the obtained mixed solution a shown in Table 1 Concentration of peroxotitanic had mixed. Which he preserved mixture liquid was completely using a homomixer stirring. An aqueous ceramic titanium dioxidanstrich was obtained.

As a result of analysis, it was confirmed that the obtained aqueous coating crystalline anatase titanium dioxide as colloidal particles having a mean particle size of 0.05 microns contained.

example 9

An aqueous titanium tetrachloride solution (20 weight percent) was placed in a beaker with water ver thinned. The dilute aqueous solution at a Tempe temperature of 80 ° C. for 10 minutes and then with water a temperature of 30 ° C cooled.

The resulting liquid was egg using ner anion exchange membrane at a temperature of 27 ° C subjected to diffusion dialysis, which deionized water un ter hydrolysis and converting a portion of the Titantetrachlo rids to orthotitanium acid and crystalline titanium dioxide flowing through the membrane, said impurity ions out of the obtained aqueous paint were removed.

example 10

An aqueous titanium tetrachloride solution (20 weight percent) was placed in a beaker with water ver and diluted with an aqueous solution of 10 weight percent Sodium hydroxide in an amount of one mole per mole of titanium, which was present in the aqueous titanium tetrachloride solution, ver mixed. The mixed liquid was heated to a temperature of 55 ° C heated for 60 minutes and then to a temperature of 30 ° C water-cooled. The heated liquid was Dif fusion dialysis using a Zellophanmembran at a temperature of 25 ° C subjected while the Hydro lyse and converting at least a portion of the aq Titanium tetrachloride serigen starting solution contained about Or thotitansäure and crystalline titanium dioxide desioni ized water ran through the membrane, which contami supply versions were removed from the aqueous liquid.

The resulting titanium dioxide colloid containing liq fluid was mixed with 0.5 percent by weight of lactic acid (complexation approximately medium) mixed.

example 11

An aqueous 20 weight percent titanium trichloride solution was placed in a beaker and ver with water thinned. The diluted solution was watery with a 31% hydrogen peroxide solution mixed until purple ge colored titanium (III) ions completely in the aqueous solution to colorless titanium (IV) ions were converted. The resulting aqueous titanium tetrachloride solution was watery with a Solution of 10 weight percent sodium hydroxide in an amount of 2 moles per mole of titanium, which was present in the aqueous solution, mixed. The mixed solution was heated to a temperature heated from 70 ° C for 30 minutes and then a water-on Temperature of 30 ° C cooled. The obtained liquid was using an RO membrane at a temperature of subjected to 40 ° C diffusion dialysis treatment while desioni ized water was passed through the membrane under Her position of a substantially impurity ions free aqueous ceramic titanium dioxide paint.

example 12

An aqueous 20 weight percent titanium trichloride solution was placed in a beaker and ver with water thinned. The diluted solution was watery with a 31% hydrogen peroxide solution mixed until purple ge colored titanium (III) ions completely in the aqueous solution to colorless titanium (IV) ions were converted. The resulting aqueous titanium tetrachloride solution was watery with a Solution of 10 weight percent sodium hydroxide in an amount ver 0.24 mol per mole of titanium in the aqueous solution mixed. The mixed solution was heated to a temperature of heated to 95 ° C for 5 minutes and then with water to a Tem temperature of 30 ° C cooled. The obtained liquid was using an anion exchange membrane and a Cation exchange membrane at a temperature of 30 ° C Dif undergo fusion dialysis treatment while deionized Water was passed through the membrane, to produce a substantially free of impurity ions, wässe Liquid engined containing titanium dioxide. The aqueous Ti dioxide-containing liquid was measured with a complexation agent selected from acetylacetone in an amount of 1.2 Ge weight percent was mixed.

example 13

An aqueous 30 weight percent Titansulfatlö solution was placed in a beaker and diluted with water. The diluted solution was used for a temperature of 65 ° C heated 90 minutes and then diluted with water to a temperature cooled from 30 ° C.

The aqueous heat-treated solution was electric dialysis treatment in an electrodialysis vessel with at odenkammer containing an anode consisting of platinum-plated Titanium plate and a cathode chamber, including a Cathode consisting of platinum-plated titanium plate under coated, wherein the anode and cathode chamber by a Anio exchange membrane (trademark: Selemion AMV Herge, represents Asahi Garasu KK) were separated. The Anode plate, the anion exchange membrane and the cathode plate were in this order parallel to one another assigns, the anode chamber with heat-treated titanium dioxide containing aqueous liquid filled and the cathode chamber filled with water. Electrodialysis treatment at a current density of 1-5 A / dm² at a temperature run of 45 ° C.