Photocatalytic ceramic glaze composition
Abstract
Ceramic glaze composition. The present invention refers to a ceramic glaze composition characterized by comprising, in percentage by weight with respect to the total weight of the composition: a) from 50 to 90% by weight of a product that in turn comprises from 10 to 90% by weight of a compound with photocatalytic properties and from 10 to 90% by weight of at least one natural and/or synthetic material selected from a group of substances with a feldspar or feldspar structure; b) from 5 to 50% by weight of at least one fluxing additive; c) from 0.5 to 20% by weight of sodium tripolyphosphate. The method for preparing said ceramic glaze, as well as its application in ceramic pieces capable of reducing the NOx present in the air, will also be the object of this invention.

Term
3.2 yearsleft in the term
Expires 20 November 2029.
- Priority and filed
- Granted
- Today
- Expires
12 claims: 3 independent, 9 dependent
- 1ES 2 335 262 B1 REIVINDICACIONES 1. Composición de esmalte cerámico caracterizada por comprender, en porcentaje en peso respecto al peso total de la composición:a) de un 50 a un 90% en peso de un producto que a su vez comprende de un 10 a un 90% en peso de un compuesto con propiedades fotocatalíticas y de un 10 a un 90% en peso de al menos un material natural y/o sintético seleccionado de un grupo de sustancias con estructura de feldespato o feldespatoide;b) de un 5 a un 50% en peso de al menos un aditivo fundente;c) de un 0,5 a un 20% en peso de tripolifosfato sódico.
- 2Composición, de acuerdo a la reivindicación 1, donde el compuesto con propiedades fotocatalíticas consiste en dióxido de titanio en forma de Anatasa.
- 3Composición, de acuerdo a la reivindicación 1, donde dicho compuesto con propiedades fotocalíticas es seleccionado de un grupo que consiste en SrTiÓ 3 , KtaO 3 , ZrÓ 2 , ZnS, CdSe, GaP y SiC, así como cualquier combinación de los anteriores.
- 4Composición, de acuerdo a una cualquiera de las reivindicaciones 1 a 3, donde el aditivo fundente consiste en fritas cerámicas caracterizadas por comprender de un 30 a un 80% en peso de óxido de plomo fritado, de un 15 a un 70% en peso de dióxido de silicio (SiÓ 2 ), de un 1 a un 10% en peso de óxido de Zinc (ZnO), de un 1 a un 8% en peso de óxido de Sodio (Na 2 Ó), de un 0.5 a un 6% en peso de óxido de Titanio (TiÓ 2 ) y de un 0,2 a un 6% en peso de trióxido de dialumino (Al 2 Ó 3 ).
- 5Composición, de acuerdo a una cualquiera de las reivindicaciones 1 a 4, donde el aditivo fundente es seleccionado de un grupo que consiste en MgÓ y Li 2 Ó, así como cualquiera de sus combinaciones.
- 6Composición, de acuerdo a una cualquiera de las reivindicaciones anteriores, caracterizada por comprender, de manera adicional, entre un 30 y un 60% en peso de la mezcla total de al menos un vehículo serigráfico.
- 7Composición, de acuerdo a la reivindicación 6, donde dicho vehículo serigráfico se caracteriza por comprender de un 60 a un 90% en peso de un alcohol;de un 5 a un 30% en peso de agua, y de un 5 y a un 35% en peso de una resina tipo polisacárido.
- 8Método de preparación de un esmalte cerámico a partir de una composición de acuerdo a una cualquiera de las reivindicaciones 1 a 7 caracterizado porque comprende las siguientes etapas:a) el mezclado de los elementos constituyentes de la composición de esmalte cerámico;b) el acondicionamiento de la mezcla anterior mediante micronizado en molino de microbolas o mediante homogenización por agitación y posterior tamizado hasta obtener una composición sólida con un rechazo en húmedo de 0% medido en tamiz de 45 micras;c) el mezclado de la composición sólida de la etapa anterior con un vehículo serigráfico en un porcentaje en peso comprendido entre un 30 y un 60%.
- 9Esmalte cerámico obtenido a partir del método de preparación de acuerdo a la reivindicación 8, caracterizado por comprender un valor de densidad a 25°C de 1,55 a 1,85 Kg/l.
- 10Pieza cerámica sometida a una cocción entre 45 y 70 minutos con una zona de máxima temperatura de entre 750°C y 1150°C;caracterizada porque al menos una de sus caras comprende un esmalte cerámico de acuerdo a la reivindicación 9.
- 11Pieza cerámica, de acuerdo a la reivindicación 10, donde al menos una de sus caras comprende un esmalte cerámico obtenido a partir de una composición de esmalte cerámico que a su vez se caracteriza por comprender:a) de un 50 a un 90% en peso de un producto que a su vez comprende de un 10 a un 90% en peso de un compuesto con propiedades fotocatalíticas y de un 10 a un 90% en peso de al menos un material natural y/o sintético seleccionado de un grupo de sustancias con estructura de feldespato o feldespatoide;b) de un 5 a un 50% en peso de al menos un aditivo fundente;c) de un 0,5 a un 20% en peso de tripolifosfato sódico.
- 12Uso de una pieza cerámica de acuerdo a cualquiera de las reivindicaciones 10 o 11 para la reducción continua por vía fotocatalítica del NÓ2 y NÓ presentes en el aire.
Independent claims12
54 paragraphs in 4 sections, as filed
ES 2 335 262 B1
DESCRIPTION
Ceramic glaze composition.
Technical field
The present invention relates to the field of ceramic glazes, more specifically to the field of ceramic glazes with photocatalytic capacity of special application in the manufacture of ceramic coatings. In particular, said coatings will be characterized as comprising semiconductor materials, especially TiO<sub>2</sub>, which, under appropriate wavelength radiation, will be capable of causing the oxidation of nitrogen oxides that come into contact with them.
Background of the invention
One of the main pollution problems that currently exists in large cities is that derived from the emissions of nitrogen oxides into the atmosphere. Nitrogen oxides (hereinafter referred to as NOx) are a mixture of gases composed of nitrogen and oxygen, among which, due to their greater toxicological importance, nitrogen monoxide and nitrogen dioxide should be mentioned.
Annually, more than 30 million tons of NOx are emitted into the atmosphere by human action. NOx is produced mainly in combustion processes, both in mobile sources (cars, trucks, or public transport), and fixed sources (incineration furnaces or power plants). Also contributing, to a lesser extent, are some specific chemical industries (production of nitric acid, uric acid, etc.).
The emission of nitrogen oxides (NOx) into the atmosphere produces a variety of health problems for the population as well as negative environmental effects on the planet. Thus, direct exposure to these oxides in concentrations above 3 ppm increases the chances of lung disease, especially in children and the elderly, and is serious for heart patients.
Likewise, NOx react with unburned hydrocarbons to form ozone, the main cause of photochemical smog, which causes, among other health problems, eye irritation, cough, headaches or respiratory problems.
In addition to the negative effects on humans and fauna, nitrogen oxides cause damage to forestry and seriously affect the growth of certain varieties of crops and fruit trees. Together with sulfur oxides, they are the main responsible for acid rain. On the other hand, NOx, mainly in its NO forms<sub>2</sub> and NO, they are gases that contribute to climate change and global warming of the planet, their influence being more damaging than that of CO<sub>2</sub>. Specifically, it is quantified that NOx is about 310 times more harmful than CO2.
Although there have been many technologies developed in order to reduce or eliminate the emissions of these polluting gases, there is still a need to design new, more economical and efficient processes, in order to achieve the decontamination levels established by the legislation without compromising the current degree of economic development and social welfare derived from the use of fossil fuels such as oil and natural gas.
In this sense, the solution proposed by the present invention is based on presenting a new composition of ceramic enamel with photocatalytic capacity, intended for the manufacture of ceramic materials capable of maintaining their photocatalytic activity continuously over time.
For some years now, the transformation capacity of organic compounds that have certain elements with photocatalytic properties has been known. In the same way, the photocatalytic character of compounds such as titanium dioxide is widely known, which has been widely used because it is an inexpensive, harmless and chemically stable compound. In this sense, the first studies that are known about the possible use of TiO<sub>2</sub> for the oxidation of organic molecules were developed by Teichner et al. (PC Gravelle, F. Juillet, P. Meriaudeau and SJ Teichner, Discuss. Faraday Soc., 52, 140 (1971); M. Formenti, F. Juillet, P. Meriaudeau and SJ Teichner, Chem. Technol., 1,680 ( 1971)).
However, most of the research carried out to date has focused on the study of the photodegradation mechanism, as well as the properties of the process catalysts themselves.
Despite this, studies have also been carried out, mainly in Japan, aimed at the possibility of treating low concentrations of NOx by photocatalysis. Thus, for example, the works of Ichiura et al. focus on the study of the photocatalytic oxidation of NOx on titanium dioxide plates modified with metallic compounds (Ichiura, H., Kitaoka, T., Tanaka, H., “Photocatalytic oxidation of NOx using composite sheets containing TiO<sub>2</sub> and a metal compound ”, Chemosphere 51, 855 (2003)). In the same way, Dalton et al. have studied the photocatalytic degradation of NOx in the atmosphere, using TiO<sub>2</sub> as a photocatalyst (Dalton, JS, Janes, PA, Nicholson, JA, Hallam, KR, Allen, GC, “Photocatalytic oxidation of NOx gases using TiO<sub>2</sub>: a surface spectroscopic approach ”,
ES 2 335 262 B1
Environ. Pollut. 120,415 (2002)). Also in the bibliography it is possible to find works on the application of TiO<sub>2 </sub>for the prevention of the effects of pollution in buildings under solar irradiation (A. Fujishima, Taiyo Enerugi, 26 (2), 2-6 (2000)).
In the patent literature, mention should be made, among others, of international applications WO97 / 10185, WO97 / 10186, WO99 / 44954 or WO2006 / 030250 A2, as well as patents such as ES2265150, in which the photocatalytic capacity of TiO2 is described. as well as its application, for example, in the manufacture of coatings or in the self-cleaning of surfaces.
In this sense, the object of this invention will be to present a new ceramic enamel composition capable of achieving highly effective results in terms of reducing the level of nitrogen oxides, while allowing said efficacy to be maintained for a long period of time. In this way, it is possible to provide structural elements such as, for example, the tiles used in the cladding of buildings, with an additional functionality to the simple and mere decorative function that said ceramic elements normally have.
Description of the invention
The present invention refers to a new ceramic glaze composition characterized by comprising:
a) from 50 to 90%, preferably from 60 to 85% by weight of solid of a product whose composition and production procedure are claimed in the Spanish patent application n ° 200900188 of FMCFORET SA, a product that a in turn, it comprises from 10 to 90%, preferably from 40 to 60%, of a compound with photocatalytic properties and from 10 to 90%, preferably from 40 to 60% of at least one natural and / or synthetic material selected from a group of substances with a feldspar or feldspathoid structure;
b) from 5 to 50%, preferably, from 15 to 40% by weight of solid of the composition of at least one flux additive;
c) from 0.5 to 20%, preferably from 1 to 10% by weight of solid of the sodium tripolyphosphate composition.
The compound with photocatalytic properties will preferably consist of titanium dioxide in its Anatase crystal structure. However, additionally, said compound with photocatalytic properties may be selected from a group consisting of SrTiO<sub>3</sub>, KTaO<sub>3</sub>, ZrO<sub>2</sub>, ZnS, CdSe, GaP and SiC, as well as any combination of the above.
For their part, the natural and / or synthetic materials present in the composition are characterized by being inert, non-toxic, and without photocatalytic activity. As is known, feldspathoids are porous tectosilicates containing aluminum and silicon in similar proportions, which form a negatively charged three-dimensional structure that is compensated with cations.
Its main function will be to avoid the photocatalytic deactivation of titanium dioxide, thus enhancing its effectiveness and durability. In this way, these natural and / or synthetic materials, intimately mixed with the TiO<sub>2</sub>, generate a synergistic effect by which the photocatalytic activity and durability are enhanced, so that the ceramic glaze is capable of initially producing a more significant abatement of the NOx from the surrounding atmosphere than if the TiO2 were pure. Later, once the steady state is reached, they allow the ceramic glaze to maintain a constant and lasting activity over time, while the pure TiO2 would be inactivated by poisoning. In the present invention, thanks to the presence of these materials, the anions product of the photooxidation of NOx are reversibly deposited on the surface of the feldspathoids, thus keeping TiO2 its photocatalytic activity unchanged. In a preferred embodiment of the invention, a mixture of various feldspathoids will be used, obtained from the direct combination of their components or by heat treatments from precursors.
Finally, the flux additive will preferably consist of frits whose chemical composition will determine the desired flux. Preferably, said frits will comprise, as major components, lead oxide (PbO) frit (inert, not soluble in water), in a percentage between 30 and 80% by weight of the frits, preferably between 50 and 70 % and silicon dioxide (SiO<sub>2</sub>) in a percentage between 15 and 70% by weight of the frits, preferably between 20 and 35%. As minor components, the frits will comprise Zinc oxide (ZnO) between 1 and 10% by weight of the frits, Sodium oxide (Na<sub>2</sub>O) between 1 and 8% by weight of the frits, Titanium oxide (TiO<sub>2</sub>) between 0.5 and 6% by weight of the frits and dialuminum trioxide (Al<sub>2</sub>OR<sub>3</sub>) between 0.2 and 6% of the weight of the frits.
As an alternative, other types of compounds that can be used as flux additives are MgO or Li<sub>2</sub>Or, as well as any of its combinations.
The described ceramic composition containing the particles of titanium dioxide (TiO<sub>2</sub>) in combination with feldspars and / or feldspathoids in the proportions claimed in application No. 200900188, once cooked and exposed to sunlight, it is capable of maintaining the enhanced photocatalytic properties of TiO<sub>2</sub> being
ES 2 335 262 B1 capable of oxidizing nitrogen oxides (NOx) that come into contact with it without reducing its effectiveness over time. This aspect is one of the main advantages of the present invention, being also one of the characteristics that make it novel compared to the current state of the art.
Said oxidation process is based on the generation of hydroxyl radicals capable of degrading polluting compounds, giving rise to substances that are harmless to the environment. The hydroxyl radical is a powerful oxidizing agent that oxidizes nitrogen dioxide (NO<sub>2</sub>) transforming it into nitrate ion. For its part, the superoxide ion is capable in turn of transforming nitrogen monoxide (NO) into nitrate ions.
In a preferred embodiment of the invention, the composition described above will also comprise between 30 and 60%, preferably between 35 and 50%, by weight of the total mixture, of at least one screen-printing vehicle characterized by comprising, in turn, between 60 and 90% by weight of at least one alcohol, preferably polyglycol; between 5 and 30% by weight of water and between 5 and 35% by weight of a polysaccharide type resin.
For the preparation of the ceramic glaze made from the composition described above, it is not necessary to carry out any special modification with respect to the usual processes and procedures in the manufacture of ceramic products. Thus, said method of preparing the ceramic glaze comprises the following stages:
a) The mixing of the constituent elements of the ceramic enamel composition;
b) The conditioning of the previous mixture by means of a process that may consist of micronization in a microball mill or homogenization by stirring and subsequent sieving until obtaining a mixture or solid composition with a wet rejection of 0% measured on a 45 sieve. microns;
c) mixing the solid composition from the previous step with the screen printing vehicle in a percentage comprised between 30 and 60%, preferably between 35 and 50% by weight.
An additional object of this invention is directed to the ceramic glaze obtained from the previous procedure, which is characterized by having density values (at 25 ° C) between 1.55 and 1.85 kg / l.
Likewise, the object of this invention will be a ceramic piece characterized in that at least one of its faces comprises the ceramic enamel described above. Said ceramic piece will preferably be of the porcelain type, with a water absorption of less than 0.5%.
In a preferred embodiment of the invention, the procedure for obtaining said ceramic piece will comprise the previous firing and decoration thereof, followed by the application of the photocatalytic enamel on the porcelain enamel of said piece by means of one of the usual screen printing application systems. in the production of ceramics. These systems include, preferably, screen printing, gravure systems and airbrush systems.
In a preferred embodiment in which the application system is carried out by intaglio, the enamel will be deposited in the cavities of a matrix located in part of a smooth and elastically deformable cylindrical surface. The excess enamel deposited on the matrix will be removed by using a doctor blade or blade, which in turn will allow the enamel to be remixed continuously, producing at least a partial renewal within the cavities of the matrix. Finally, the transfer of the enamel contained in the cavities of the matrix to the ceramic piece will occur by direct contact, that is, by rolling continuously and without dragging said matrix on the surface of the ceramic piece.
Once the glaze has been deposited, the decorated ceramic piece will be subjected to a firing cycle of between 45 and 70 minutes in an industrial oven, according to a firing curve with a bearing or zone of maximum stable temperature of 750 ° C to 1150 ° C .
Finally, the object of this invention will be the use of said ceramic pieces to reduce the percentage of NOx in the environment. In this way, in the event that said ceramic piece is a tile on which a layer of the enamel object of the invention has been deposited, it will be possible to degrade 3.63 mg of NOx per m<sup>2</sup> and hour, equivalent to an 18.8% reduction in the NOx concentration in the atmosphere. In the same way, in a particular application involving, for example, 200 8-storey buildings with a surface area of 4800 m<sup>2</sup> each one covered with said tiles, it will be possible to eliminate about 238,491,000 mg in weight NOx / year, assuming the same insolation of 12 hours a day, 365 days a year.
On the other hand, an additional advantage that these ceramic pieces present is their regeneration by simple washing, natural or voluntary, with water. In this way, in washing, the ions resulting from the photocatalytic oxidation are dissolved in the water, being able to be completely eliminated and, therefore, allowing to recover the initial photocatalytic activity of the enamel.
ES 2 335 262 B1
Preferred embodiment of the invention
Three preferred embodiments of the present invention are listed below, by way of example and without limitation.
Example 1
Composition 278BCB1
In this first example, a ceramic glaze with the following composition was used: a solid preparation composed of 84% by solid weight of the product whose composition and production procedure are claimed in Spanish patent application No. 200900188; 1% by weight of sodium tripolyphosphate solid and 15% by weight of solid of a flux additive, the composition of said additive being the following: 55% lead oxide PbO, 22% silicon dioxide SiO<sub>2</sub>, 7% Zinc oxide ZnO, 7% sodium oxide Na<sub>2</sub>0.5% Titanium Oxide TiO<sub>2</sub> and 4% dialuminium trioxide Al<sub>2</sub>OR<sub>3</sub>. Said solid composition was mixed and homogenized with the screen printing vehicle in a percentage of 50% by weight of the total mixture, said screen printing vehicle being in turn composed of 85% of a polyglycol, 10% of water and 5% of polysaccharide resin. The resulting mixture presented a rejection of 0% on a 45 micron sieve and the resulting enamel was conditioned to a density of 1.68 Kg / l. The referred photocatalytic enamel was applied to a porcelain-type ceramic piece (with a water absorption of less than 0.5%), previously decorated and fired. The piece with the photocatalytic enamel was then subjected to a 50-minute firing cycle with a maximum firing temperature of 910 ° C. The photocatalytic piece thus obtained was tested according to the ISO 22197-1: 2007 standard to determine its degree of activity, offering a value of 0.68 ppm / hour of NOx decomposition.
Example 2
Composition 205SBB1
In this example, a ceramic glaze with the following composition was used: a solid preparation made up of 60% by solid weight of the product whose composition and production procedure are claimed in Spanish patent application no. 200900188; 5% by weight of sodium tripolyphosphate solid and 35% by weight of flux additive solid, the composition of said additive being the following: 50% lead oxide PbO, 35% silicon dioxide SiO2, 2% Zinc oxide ZnO, 5% sodium oxide Na2O, 5% titanium oxide TiO2 and 3% dialuminum trioxide Al<sub>2</sub>OR<sub>3</sub>. Said solid composition was mixed and homogenized with the screen printing vehicle in a percentage of 55% by weight of the total mixture, said screen printing vehicle being in turn composed of 80% polyglycol, 10% water and 10% resin. polysaccharide type. The resulting mixture presented a rejection of 0% on a 45 micron sieve, and the resulting enamel was conditioned to a density of 1.58 Kg / l. The referred photocatalytic enamel was applied to a porcelain-type ceramic piece (with a water absorption of less than 0.5%), previously decorated and fired. The piece with the photocatalytic enamel was then subjected to a firing cycle of 68 minutes with a maximum firing temperature of 875 ° C. The photocatalytic piece thus obtained was tested according to the ISO 22197-1: 2007 standard to determine its degree of activity, offering a value of 0.59 ppm / hour of NOx decomposition.
Example 3
Composition 265BCB1
In this example, a ceramic glaze with the following composition was used: a solid preparation composed of 75% by solid weight of the product, the composition and method of obtaining it are claimed in Spanish patent application No. 200900188; 1% by weight of sodium tripolyphosphate solid and 24% by weight of flux additive solid, the composition of said additive being the following: 60% of lead oxide PbO, 25% of silicon dioxide SiO2, 6% of Zinc oxide ZnO, 4% sodium oxide Na2O, 3% titanium oxide TiO2 and 2% dialuminium trioxide Al2O3. Said solid composition was mixed and homogenized with the screen printing vehicle in a percentage of 45% by weight of the total mixture, said screen printing vehicle being in turn composed of 85% polyglycol, 6% water and 9% resin. polysaccharide type. The resulting mixture presented a rejection of 0% on a 45 micron sieve, and the resulting enamel was conditioned to a density of 1.62 Kg / l. The referred photocatalytic enamel was applied on a porcelain-type ceramic piece (with a water absorption of less than 0.5%), previously decorated and fired. The piece with the photocatalytic enamel was then subjected to a firing cycle of 60 minutes with a maximum firing temperature of 800 ° C. The photocatalytic piece thus obtained was tested according to the ISO 22197-1: 2007 standard to determine its degree of activity, offering a value of 0.85 ppm / hour of NOx decomposition.
The figure that accompanies this description (Fig. 1) shows the comparative results of the three previous examples, according to the adaptation of the ISO 22197-1 2007 STANDARD.
Contents4
1 sheet
Sheet 1
10 members in 5 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 200931033 | Spain | A | |
| ES20090031033 | – | – | – |
Members10
| Document | Office | Kind | |
|---|---|---|---|
| ES2335262A1 | Spain | A1 | |
| ES2335262B1This record | Spain | B1 | |
| EP2324917A2 | European Patent Office (EPO) | A2 | |
| WO2011061381A1 | World Intellectual Property Organization (WIPO) | A1 | |
| EP2324917A3 | European Patent Office (EPO) | A3 | |
| CN102917995A | China | A | |
| US2013092050A1 | United States of America | A1 | |
| CN102917995B | China | B | |
| EP2324917B1 | European Patent Office (EPO) | B1 | |
| ES2623862T3 | Spain | T3 |
4 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Announcement of lapse in spainLapsedFD2A | FD2A | |
| Transfer of patentPC2A | PC2A | |
| Definitive protectionFG2A | FG2A | |
| Search report publishedEC2A | EC2A |
Numbers
- Publication
- 2335262
- Publication, DOCDB
- 2335262
- Publication, EPODOC
- ES2335262
- Application
- 31033
- Application, DOCDB
- 200931033
- Application, EPODOC
- ES20090031033
Titles2
- Spanish
- COMPOSICION DE ESMALTE CERAMICO
- English
- CERAMIC ENAMEL COMPOSITION
Classification
- CPC, 18
- C09D7/61
- C03C8/00
- B01D2255/20707
- B01J21/06
- B01J21/063
- B01J37/0215
- C03C8/12
- C03C8/16
- C03C8/20
- C03C2204/00
- C04B41/009
- C04B41/5022
- C04B41/86
- C04B2111/00827
- B01J35/39
- C04B41/85
- C04B41/87
- C09D1/00
- IPC, 6
- C03C8 00
- C04B41 85
- C04B41 86
- C04B41 87
- C09D1 00
- C09D7 61