Glass-ceramic materials and frit compositions for enamel coatings

Abstract

The present invention relates to colored glass-ceramic frits, pigments, or color additives, and methods for producing such materials. The resulting compositions can be used to form enamels for decorating and / or protecting substrates. Such crystallized glass and glass-ceramic materials are suitable for a variety of consumer electronics or automotive applications.

Description

[Technical Field]

[0001] The present invention relates to colored glass-ceramic frits, pigments, or color additives, and methods for producing such materials. The resulting compositions can be used to form enamels for decorating and / or protecting substrates. Such crystallized glass and glass-ceramic materials are suitable for a variety of consumer electronics or automotive applications.

[0002] In particular, the present invention relates to colored crystallized glass and glass-ceramic frit compositions for use in decorative enamel, coating, and sealing articles (or applications), and methods for making the same. The crystallized glass and glass-ceramic compositions provide controllable (or tunable) residual glass and crystalline phases during the ceramming process. The crystalline phase may include crystallites of ilmenite solid solution, for example, referred to as the Fe2O3-TiO2-MnO2 system. The term ilmenite solid solution refers to the ideal formula Fe 1-x M x It is not limited to TiO3, but also includes ilmenite-related components having other relationships between (Fe,M) and Ti, such as ulvospinel ((Fe,Mn)2TiO4) and / or ferropseudobrookite ((Fe,Mn)Ti2O5). When used, the formula Fe 1-x M x TiO3 also includes these ilmenite-related species.

[0003] The softening temperature of such glass-ceramics can be varied over a wide range from 500 to 1000°C, which exhibits good flow behavior or high-temperature stability at conventional decorative firing temperatures. In another aspect of the present invention, the crystal size of the glass-ceramics can also be adjusted over a similarly wide range, particularly in the range from 0.05 μm to 5 μm.

[0004] Depending on the crystal size (nm, μm) in the glass or glass-ceramic, the transmittance can vary from 1% to less than 8% or even less than 1%, especially from 380 to 740 nm, and the haze can vary from 5 to less than 100 (especially for sample thicknesses of 0.5 to 25 μm, more preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm). The thickness can especially be that of the enamel layer.

[0005] To form a glass frit having a higher optical density (especially greater than 2), the crystal size is preferably greater than 0.05 μm and / or less than 10 μm, e.g., 0.1 to 7.5 μm, 0.2 to 5.0 μm, or 0.5 to 3.5 μm. The crystal size may be, for example, greater than 0.05 μm, e.g., at least 0.1 μm, at least 0.2 μm, or at least 0.5 μm. The crystal size may be, for example, up to 10 μm, e.g., up to 7.5 μm, up to 5.0 μm, or up to 3.5 μm.

[0006] The glass or glass-ceramic of the present invention exhibits good chemical durability against acidic and basic chemicals.

[0007] The resulting compositions can be used as frits, pigments, and / or color additives. Advantageous applications are so-called dead-front applications, particularly in household devices, where, for example, display elements are only visible when the display is activated.

[0008] Background technology Colored glass frit or crystallized glass frit compositions are known in the art. However, there are difficulties and drawbacks associated with the prior art.

[0009] For example, Japanese Patent Application Laid-Open No. 2001-89189 discloses a ceramic colorant composition that uses (Fe,Mn)2O3 with a bixbyite structure as a heat-resistant pigment powder. However, a ceramic colorant layer-bonded glass plate that uses such a ceramic colorant composition has problems such as low sinterability of the ceramic colorant layer and a whitish appearance when observed through the glass plate from the unfired side of the ceramic colorant layer.

[0010] U.S. Pat. No. 5,710,081 discloses and claims a specific black glass frit made by a process of contacting a metal oxide-containing glass melt with a reducing agent. In the method of the patent, metal oxide-forming glass raw materials (containing iron oxide at a concentration of 0.5 to 3.0 weight percent) and sulfur are melted in a reducing gas atmosphere at a temperature of 1000°C to 1200°C to form a melt, which is then quenched to form a frit. Glasses made by the method of the invention are not highly absorbent and do not exhibit strong color when applied as thin films (i.e., films less than 30 μm, preferably less than 20 μm, and more preferably less than 10 μm). While the method described in U.S. Pat. No. 5,710,081 reduces iron oxide to iron sulfide in the melt in a reducing atmosphere, the color pigments formed by such methods tend to precipitate from the melt; therefore, frits formed from such glass melts have relatively low concentrations of color pigments and relatively poor optical properties.

[0011] JP 2003-183047 A describes a red-colored glass that is subsequently converted into a red-colored glass-ceramic. The inventors note that it is difficult to maintain the desired shade of red during the conversion of the glass into a glass-ceramic. A special glass composition containing at least one oxide of a divalent metal and Bi2O3 is proposed. This type of colored glass can be converted into a glass-ceramic while maintaining its color.

[0012] Glass compositions according to EP 0 482 535 having colouring components based on FeO, selenium and CoO are only grey, not black.

[0013] WO 2020 / 256887 relates to Pb-free colored glass frits containing transition metal oxides such as Fe2O3, MnO2, Cr2O3, and Co3O4.

[0014] US Patent Application Publication No. 2002 / 0197408 relates to a method for producing a recyclable black enamel containing at least zinc, in which glass-forming materials containing at least bismuth, silicon, boron and manganese are melted at a temperature above 900°C.

[0015] As discussed above, the colored compositions disclosed by these patent publications and co-pending applications all differ in certain important respects from the novel compositions disclosed herein. In particular, ceramic colorant layer-bonded glass plates using (Fe,Mn)2O3-containing ceramic colorant compositions exhibit sinterability problems (JP 2001-89189 A). Glass colored with iron sulfide results in poor optical properties (U.S. Pat. No. 5,710,081). Glass colored with FeO, selenium, and CoO is gray, not black (EP 0482535 B1).

[0016] In summary, the prior art does not present any colored glass frits that allow black decoration with a transmittance of less than 1 to 8% (or even less than 1%) and a haze of less than 5 to 100 at low layer thicknesses (in particular 0.5 to 25 μm, more preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm) that can be used for decorative purposes.

[0017] Brief Summary of the Invention One object of the present invention is to provide a colored glass frit that can be applied to the decoration of glass / glass-ceramics to obtain durable coatings with good opacity.

[0018] Colored glass frits can be prepared by adding transition metal ions to such compositions to form colored glass frits of the formula Fe after crystallization of the resulting glass frit. 1-x M x It can be obtained by forming an ilmenite solid solution in the final colorant layer as a crystal system represented by TiO3 (M = Mn, Mg, Ni, Co, Zn, Cu, Cr, or a combination of two or more thereof). Optionally, the colored glass frit composition contains coloring oxides such as Bi2O3, CeO2, VO5, MoO3, WO3, etc., in an advantageous content of less than 2% by weight, more advantageously less than 1% by weight. Said oxides can also form colloids, which may be formed in particular by melting under reducing conditions.

[0019] In the context of this specification, the term ilmenite solid solution is used, which refers to the solid solution of the ideal formula Fe 1-x M x It is not limited to TiO3, but also includes ilmenite-related components having other relationships between (Fe,M) and Ti, such as ulvospinel ((Fe,Mn)2TiO4) and / or ferropseudobrookite ((Fe,Mn)Ti2O5). When used, the formula Fe 1-x M x TiO3 also includes these ilmenite-related species. Or, in other words, the present invention provides TiO3 of the ideal formula Fe 1-x M x TiO3 or formula (Fe 1-x ,M x )2TiO4 or (Fe 1-x ,M x )Ti2O5, formula (Fe 1-x ,M x )2TiO4 or (Fe 1-x ,M x ) an ilmenite solid solution having Ti2O5 crystallites, wherein M is selected from the group consisting of Mn, Mg, Ni, Co, Zn, Cu, Cr, and combinations of two or more thereof, and x is in the range of 0 to 0.8.

[0020] To obtain such crystallites in the final decorative layer, the following processing steps are preferably used: 1) Weighing the selected oxide powder (glass raw material) 2) Melting in a reducing atmosphere 3) Rapid cooling of the melt 4) The decorative layer can be produced by the following different steps: Crystallization of the quenched material, preferably at a temperature above 500° C. and below 1000° C., in particular for a time of 0.5 to 12 hours. The heating rate is preferably in the range of 2 to 10 K / min. b. Crushing the crystallized glass to an average particle size d50 of 0.35-5 μm, more preferably 0.5-3 μm, more preferably 1-1.5 μm. c. Preparing a colorant paste by adding a screen printing medium and / or pigments, in particular having a particle size d50 of less than 1 μm, advantageously between 0.2 μm and 0.5 μm. d. Applying, such as by screen printing. e. During firing of the decorative layer at a preferred temperature of 400 to 1000°C (more preferably 650 to 950°C), the crystallized glass melts but retains its colored crystallites, thus leaving behind a colored decorative layer.

[0021] In such an embodiment, the glass-ceramic material of the present invention is obtained in step 4a, and the glass-ceramic frit is obtained by grinding step 4b.

[0022] Step c can be advantageously used to adjust the color appearance of the layer. The optional addition of color pigments includes the addition of color pigments that can induce color changes and / or correct color changes in the material and the layer therewith. Color pigments are commercially available and need not be described in further detail herein.

[0023] A different approach to obtain a black glass frit that can be used for the decorative layer according to an alternative embodiment of the invention is as follows: a. Crushing virgin glass to a particle size d50 of preferably 0.35-5 μm, more preferably 0.5-3 μm, more preferably 1-1.5 μm. b. Preparing a colorant paste by adding a screen printing medium and / or pigment, particularly having a particle size d50 of less than 1 μm. c. Applying, such as by screen printing. d. During firing of the decorative layer, preferably at temperatures of 400-1000°C (more preferably 650-950°C), the glass melts and crystallizes, leaving behind a colored decorative layer.

[0024] In any case, the crystalline content is always kept below 100% by weight so as to maintain the original glass properties and to allow the heat-treated glass to be further processed to produce glass frits and decorations. Further processing includes, in particular, firing of the glass frits during production.

[0025] The main advantages of the ilmenite-based glass or glass-ceramic frit of the present invention can be summarized as follows:

[0026] Colored glass frit or low Fe content 1-x M x Frits containing a TiO3 crystal system provide transmittances of less than 1% to less than 8% and hazes of 5 to less than 100, particularly at sample thicknesses of 0.5 to 25 μm, more preferably 0.5 to 10 μm, and more preferably 0.5 to 8 μm.

[0027] Fe 1-x M x Glass or crystallized frits or glass-ceramic frits containing TiO3 in particular provide a transmittance of less than 1% to 5% and a haze of 5 to less than 100 at sample thicknesses of 0.5 to 25 μm, more preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm.

[0028] Currently, there are no decorative solutions for transmittances below 5% or 8% and hazes below 65. In particular, there are no decorative solutions for optical densities between 0.6 and 3 and hazes below 100, especially between 5 and 100. Furthermore, known organic pastes have poor scratch resistance and do not pass sclerometer tests at 10N or 20N. The present invention offers an alternative to very expensive organic colorants. All pigment-containing coatings can advantageously achieve high hazes, especially values ​​above 50 or 80.

[0029] The partially crystallized colored glass frit retains its low softening temperature (especially below 650°C).

[0030] Coatings containing such glass frits can be fired under advantageous manufacturing conditions, in particular between 400° C. and 1000° C., in particular between 600° C. and 950° C., or above 550° C. and / or below 700° C. The particle size d50 is particularly advantageously greater than 0.7 μm.

[0031] Coatings containing such glass frits advantageously provide optical densities in the range of 0.6 or more to less than 3, especially for light having a wavelength of 400 to 750 nm.

[0032] Possible applications for such colored glass frits range from the decoration of soda-lime glasses, borosilicate glasses, and glass-ceramics to applications such as glass sealing.

[0033] Detailed Description of the Invention In one aspect, the present invention relates to a glass-ceramic material comprising at least 80.0 wt. % of a glass phase and at least 0.1 wt. % of a crystalline phase, the crystalline phase comprising a predominant crystalline phase of greater than 50 wt. % relative to the total weight of the crystalline phase. In some embodiments, the predominant crystalline phase comprises crystallites from the Fe2O3-TiO2-MnO2 system. As previously mentioned, metal colloids may also be present, as well as coloring oxides and / or coloring pigments.

[0034] In some embodiments, the glass phase fraction is in the range of 80.0 wt.% to 99.9 wt.%, e.g., 82.5 wt.% to 99.5 wt.%, 85.0 wt.% to 99.0 wt.%, 87.5 wt.% to 98.0 wt.%, or 90.0 wt.% to 97.0 wt.%. The glass phase fraction may be, in particular, at least 80.0 wt.%, at least 82.5 wt.%, at least 85.0 wt.%, at least 87.5 wt.%, or at least 90.0 wt.%. The glass phase fraction may be, in particular, up to 99.9 wt.%, up to 99.5 wt.%, up to 99.0 wt.%, up to 98.0 wt.%, or up to 97.0 wt.%.

[0035] In some embodiments, the proportion of the crystalline phase is in the range of 0.1 wt.% to 20.0 wt.%, e.g., 0.2 to 15.0 wt.%, 0.5 to 12.5 wt.%, 1.0 to 10.0 wt.%, at least 1.5 wt.% to 8.0 wt.%, or 2.0 to 6.0 wt.%. The proportion of the crystalline phase may be, in particular, at least 0.1 wt.%, at least 0.2 wt.%, at least 0.5 wt.%, at least 1.0 wt.%, at least 1.5 wt.%, or at least 2.0 wt.%. The proportion of the crystalline phase may be, in particular, up to 20.0 wt.%, up to 15.0 wt.%, up to 12.5 wt.%, up to 10.0 wt.%, up to 8.0 wt.%, or up to 6.0 wt.%.

[0036] In some embodiments, the proportion of the predominant crystalline phase is greater than 50% by weight, particularly at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, at least 99.9%, or even 100% by weight, relative to the total weight of the crystalline phase. In some embodiments, the crystalline phase may consist of the predominant crystalline phase. Thus, the predominant crystalline phase may be the only crystalline phase.

[0037] In some embodiments, the predominant crystalline phase comprises or consists of crystallites from the Fe2O3-TiO2-MnO2 system. In some embodiments, the predominant crystalline phase comprises (Fe,Mn)TiO3 crystallites or (Fe,Mn)TiO4 crystallites or (Fe 1-x ,M x ) Ti2O5 or mixtures thereof.

[0038] In some embodiments, the predominant crystalline phase is of the formula Fe 1-x M x The glass-ceramic material may comprise or consist of TiO3 crystallites, wherein M is selected from the group consisting of Mn, Mg, Ni, Co, Zn, Cu, Cr, and combinations of two or more thereof. Preferably, M is selected from the group consisting of Mn, Mg, and combinations thereof. Particularly preferably, M is Mn. In some embodiments, x is in the range of 0 to 0.80. Preferably, x is greater than 0. The component M is advantageously used to adjust the color of the glass-ceramic material. For example, it has been observed that the inclusion of Mn and / or Mg results in a deep black impression. All of the listed components M may contribute similarly and / or may even result in a color change compared to the pure ilmenite crystalline phase. To adjust the color appearance, it is also possible to add metal colloids, such as Bi or W, having a crystal size of less than 1 μm, advantageously between 0.05 μm and 0.5 μm, and / or pigments, especially having a particle size d50 of less than 1.1 μm, advantageously less than 0.7 μm, more advantageously between 0.05 μm and 0.5 μm.

[0039] When referring to crystal size, we mean the average of the major diameters obtained by measuring the dimensions of the crystallites from images obtained from an SEM (scanning electron microscope). Thus, the crystallites visible in the image are analyzed using image software. The maximum expansion of the crystallites is interpreted as the individual major diameter, and the arithmetic mean diameter is then calculated from the sum of the individual major diameters.

[0040] In some embodiments, the average crystal size of the microcrystals is in the range of 0.01 to 5.0 μm, e.g., 0.02 to 4.0 μm, 0.05 to 3.0 μm, 0.10 to 2.0 μm, 0.15 to 1.5 μm, 0.20 to 1.0 μm, or 0.25 to 0.75 μm. The average crystal size of the microcrystals may be, for example, at least 0.01 μm, at least 0.02 μm, at least 0.05 μm, at least 0.10 μm, at least 0.15 μm, at least 0.20 μm, or at least 0.25 μm. The average crystal size of the microcrystals may be, for example, up to 5.0 μm, up to 4.0 μm, up to 3.0 μm, up to 2.0 μm, up to 1.5 μm, up to 1.0 μm, or up to 0.75 μm.

[0041] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises a TiO content of 0.03 to 32 wt. %, e.g., 0.5 to 15 wt. %, 1.0 to 12 wt. %, or 2.0 to 10 wt. The TiO content may be, in particular, at least 0.03 wt. %, at least 0.5 wt. %, at least 1.0 wt. %, or at least 2.0 wt. The TiO content may be, in particular, up to 32 wt. %, up to 15 wt. %, up to 12 wt. %, or up to 10 wt. %.

[0042] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises a proportion of Fe2O3 of 0.07 to 44 wt%, e.g., 0.5 to 20 wt%, 1.0 to 15 wt%, or 2.0 to 12 wt%. The proportion of Fe2O3 may be, in particular, at least 0.07 wt%, at least 0.5 wt%, at least 1.0 wt%, or at least 2.0 wt%. The proportion of Fe2O3 may be, in particular, up to 44 wt%, up to 20 wt%, up to 15 wt%, or up to 12 wt%.

[0043] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises a proportion of MnO2 of 0.03 to 25 wt%, e.g., 0.5 to 15 wt%, 1.0 to 10 wt%, or 1.5 to 7.5 wt%. The proportion of MnO2 may be, in particular, at least 0.03 wt%, at least 0.5 wt%, at least 1.0 wt%, or at least 2.0 wt%. The proportion of MnO2 may, in particular, be up to 25 wt%, up to 15 wt%, up to 10 wt%, or up to 7.5 wt%.

[0044] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises the following components in the amounts (by weight %) indicated: [Table 1]

[0045] The term RO refers to the alkaline earth metal oxides MgO, CaO, SrO, and BaO. The term R2O refers to the alkali metal oxides Li2O, Na2O, and K2O.

[0046] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises the following components in the amounts (by weight %) indicated: [Table 2]

[0047] In some embodiments, the starting glass and / or glass-ceramic material of the present invention comprises the following components in the amounts (by weight %) indicated: [Table 3]

[0048] The glass-ceramic materials of the present invention are obtained by ceramming a suitable starting glass. The composition of the starting glass is not substantially changed by ceramming. Thus, the starting glass may have substantially the same composition as that shown above for the glass-ceramic. In one aspect, the present invention relates to each starting glass.

[0049] The glass-ceramic material of the present invention has a high percentage of glass phase, and therefore has a high density, a high glass transition temperature Tg, a high softening temperature EW(10 7.6 Properties such as the viscosity at temperature in dPas and the coefficient of thermal expansion (CTE, 20-300°C) are essentially the same for the glass-ceramic material and the starting glass. In some embodiments, the starting glass and / or glass-ceramic material has a viscosity of 2.0-4.0 g / cm 3 , for example, 2.2 to 3.5 g / cm 3 In some embodiments, the starting glass and / or glass-ceramic material has a glass transition temperature Tg in the range of 400°C to 600°C, e.g., 450°C to 550°C. In some embodiments, the starting glass and / or glass-ceramic material has a softening temperature EW in the range of 450°C to 650°C, e.g., 500°C to 600°C, e.g., 500°C to 560°C or 560°C to 600°C. In particular, the softening temperature EW may be up to 650°C, up to 600°C, or up to 560°C. In some embodiments, the starting glass and / or glass-ceramic material has a CTE(20°C, 300°C) in the range of 4.0 to 9.0 ppm / K, e.g., 4.5 to 8.0 ppm / K.

[0050] In one aspect, the present invention relates to a glass-ceramic frit comprising or consisting of grains of a glass-ceramic material, particularly comprising or consisting of grains of the glass-ceramic material of the present invention. Glass-ceramic frits are glass-ceramic materials, particularly those present in powder form. In some embodiments, the grains have a particle size d50 in the range of 0.10 to 10 μm, e.g., 0.20 to 7.5 μm, 0.35 to 5.0 μm, 0.50 to 3.0 μm, or 1.0 to 1.5 μm. The grains may have a particle size d50 of, for example, at least 0.10 μm, at least 0.20 μm, at least 0.35 μm, at least 0.50 μm, or at least 1.0 μm. The grains may have a particle size d50 of, for example, up to 10 μm, up to 7.5 μm, up to 5.0 μm, up to 3.0 μm, or up to 1.5 μm.

[0051] When referring to d50 as a particle size, this term is commonly known in particle size distribution measurement and does not need to be explained further here.

[0052] In one aspect, the present invention relates to a paste comprising a glass-ceramic frit (particularly a glass-ceramic frit of the present invention) and an organic medium. The organic medium may comprise or consist of, in particular, one or more glycol ethers, in particular 2-(2-butoxyethoxy)ethanol and / or 2-butoxyethanol. The organic medium may, for example, comprise or consist of 50 to 75% by volume of 2-(2-butoxyethoxy)ethanol and 20 to 30% by volume of 2-butoxyethanol.

[0053] The viscosity of the paste is adjusted as needed.

[0054] As mentioned above, it is also envisaged to add colour pigments to the frit and / or paste, thereby inducing and / or correcting colour changes in the material and / or layer therewith. The colour pigments may in particular have a size d50 of less than 1.1 μm or less than 0.7 μm, advantageously between 0.2 μm and 0.5 μm.

[0055] In some embodiments, the weight ratio of glass-ceramic frit to organic medium in the paste ranges from 10:10 to 10:1, such as from 10:8 to 10:2 or from 10:6 to 10:3.

[0056] In one aspect, the present invention relates to a layer composite comprising or consisting of a glass or glass-ceramic substrate layer and an enamel coating layer. In some embodiments, the enamel coating layer comprises, consists of, or is obtained from a paste comprising a glass-ceramic material (particularly a glass-ceramic material of the present invention) and / or a glass-ceramic frit (particularly a glass-ceramic frit of the present invention), the paste further comprising an organic medium. In particular, the enamel coating layer comprises, consists of, or is obtained from a paste of the present invention.

[0057] In some embodiments, the substrate comprises or consists of soda-lime glass (particularly float soda-lime glass) or borosilicate glass (particularly Borofloat® glass). The thickness of the substrate may be, for example, in the range of 0.3 mm to 20 mm, particularly 0.5 to 15 mm, 1.0 to 10 mm, or 2.0 to 8.0 mm. The substrate may be, for example, a composite glass comprising or consisting of two glass panes connected by a polymer interlayer, particularly a PVB (polyvinyl butyral) interlayer. The substrate may be, for example, a windshield, particularly a windshield having two glass panes each having a thickness of 2.1 mm and a PVB interlayer having a thickness of 0.76 mm.

[0058] In some embodiments, the enamel coating layer is obtained by coating the substrate with the paste (e.g., by screen printing) and subsequently firing the coated substrate, which may include temperatures in the range of 400°C to 1000°C, e.g., 600°C to 950°C, 650°C to 850°C, or 650°C to 750°C, among others.

[0059] In some embodiments, the thickness of the enamel coating layer is in the range of 0.1 to 30 μm, e.g., 0.5 to 25 μm, 1.0 to 15 μm, 2.0 to 12 μm, 5.0 to 10 μm, or 6.0 to 8.0 μm. The thickness of the enamel coating layer can be, for example, at least 0.1 μm, at least 0.5 μm, at least 1.0 μm, at least 2.0 μm, or at least 5.0 μm. The thickness of the enamel coating layer can be, for example, up to 30 μm, up to 25 μm, up to 15 μm, up to 12 μm, up to 10 μm, or up to 8.0 μm.

[0060] In some embodiments, the optical density of the enamel coating layer for light having a wavelength of 400 to 750 nm is at least 0.1, e.g., at least 0.31, at least 0.5, at least 0.75, at least 1.0, at least 1.25, at least 1.5, at least 1.75, at least 1.85, or at least 2.96, particularly at an enamel coating layer thickness as described above, e.g., an enamel coating layer thickness of 7 μm.

[0061] In some embodiments, the glass-ceramic material, the glass-ceramic frit, the layer composite, and / or the enamel coating layer are characterized by a particularly advantageous color impression. The color impression can be determined in accordance with the knowledge of a person skilled in the art, in particular, under illumination with illuminant D65, at a viewing angle of 10°, and at a thickness of 7 μm, in accordance with the CIELAB color space. The thickness can be, in particular, the thickness of the enamel coating layer. The L of the CIELAB color space * value, a * value, and b *The value can be determined according to the knowledge of a person skilled in the art, in particular using a KONICA MINOLTA spectrophotometer CM-700d with the enamel coating layer facing upwards.

[0062] L * The coordinates may in particular be in the ranges 1 to 80, 2 to 80, 5 to 80, 10 to 80, 20 to 80, for example 30 to 70, 35 to 60, or 40 to less than 57. * The coordinates may be, in particular, at least 1, at least 2, at least 5, at least 10, at least 20, at least 30, at least 35, or at least 40. * The coordinates may in particular be at most 80, at most 70, at most 60, or less than 57. * The most advantageous range is greater than 20 and less than 45.

[0063] a * The coordinates may in particular range from -15 to 20, for example from -10 to 15, from -5 to 10, or from 0 to 5. * The coordinate may in particular be at least −15, at least −10, at least −5, or at least 0. * The coordinates may be at most 20, at most 15, at most 10, or at most 5, among others.

[0064] b * The coordinates may be in the ranges 0 to 50, 0 to 30, 0 to 25, 1 to 20, 2 to 15, or 5 to 10, among others. * The coordinate may in particular be at least 0, at least 1, at least 2, or at least 5. * The coordinates may be at most 50, at most 30, at most 25, at most 20, at most 15, or at most 10, among others.

[0065] The gloss can be measured from the coating side or from the "observer side," i.e., from the substrate side through the substrate, including the coating. In some embodiments, the gloss at 60°, measured from the side of the coating according to the present invention, is in the range of 1 GU to 70 GU, particularly 2 GU to 65 GU, 4 GU to 60 GU, 5 GU to 55 GU, 10 GU to 50 GU, 12 to 45 GU, or 15 to 40 GU. The gloss at 60° may be, particularly, at least 1 GU, at least 2 GU, at least 4 GU, at least 5 GU, at least 10 GU, at least 12 GU, or at least 15 GU. The gloss at 60° may be, particularly, up to 70 GU, up to 65 GU, up to 60 GU, up to 55 GU, up to 50 GU, up to 45 GU, or up to 40 GU. The gloss at 60° can be determined according to the knowledge of those skilled in the art, particularly by a RHOPOINT gloss meter according to known, established measurements. The gloss is expressed in "Gloss Units" (GU). The gloss at 60°, measured through the substrate, advantageously has a GU value of 60 or more and up to 110.

[0066] In some embodiments, the enamel coating layer passes a sclerometer test at a force of 10 N, particularly at an enamel coating layer thickness in the range of 5 to 10 μm, for example 6 to 8 μm, particularly 7 μm. The sclerometer test can be carried out according to the knowledge of a person skilled in the art, particularly according to AS3894.4, EN438-2, and / or ISO4586-2, using an Elcometer 3092 and a force of 10 N.

[0067] In some embodiments, the transmittance of light having a wavelength in the range of 380 to 740 nm is less than 8%, e.g., less than 5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, or less than 0.1%, particularly when measured at a nominal thickness of the enamel coating layer of 7 μm.

[0068] In some embodiments, the haze is in the range of 5 to less than 100, e.g., 10 to 50, 15 to 30, or 20 to 25, particularly when measured at a nominal thickness of the enamel coating layer of 7 μm. The haze may be at least 5, at least 10, at least 15, or at least 20. The haze may be less than 100, e.g., at most 50, at most 30, or at most 25, particularly when measured at a nominal thickness of the enamel coating layer of 7 μm.

[0069] The fact that optical parameters (such as CIELAB parameters, optical density, transmittance or haze) are preferably determined at an enamel coating layer thickness of 7 μm does not mean that the enamel coating layer of the layer composite of the invention necessarily has such a thickness. The enamel coating layer of the layer composite of the invention may have a thickness of 7 μm, but this does not necessarily have to be the case. The thickness of 7 μm simply indicates a preferred reference thickness for optical measurements.

[0070] For example, the transmittance depends on the thickness of the enamel coating layer. Therefore, it is reasonable to set a reference thickness. For example, the transmittance may be 1% for a specific enamel coating layer thickness of 7 μm. However, the actual thickness of the enamel coating layer of the layer composite of the present invention may be 10 μm. Therefore, the present invention also includes a layer composite having an enamel coating layer with a thickness of 10 μm, for example, where the transmittance is 1% for a reference enamel coating layer thickness of 7 μm.

[0071] In one aspect, the present invention relates to a method for producing a glass-ceramic material (particularly a glass-ceramic material of the present invention) and / or a glass-ceramic frit (particularly a glass-ceramic frit of the present invention). In some embodiments, the method comprises: a) providing a starting glass; b) ceramming the starting glass by heat treatment, in particular at a temperature between 500°C and 1000°C for a duration between 1 hour and 12 hours; Includes:

[0072] The step of preparing the starting glass may in particular comprise melting the glass frits under reducing conditions (in particular a reducing atmosphere) and / or quenching the melt. Quenching may in particular comprise high speed roller quenching, water quenching, or air quenching, or a combination of two or more thereof.

[0073] In some embodiments, the ceramming temperature is in the range of 500°C to 1000°C, particularly 600°C to 950°C, for example 650°C to 900°C.

[0074] In some embodiments, the ceramming time (duration) ranges from 0.5 to 12 hours or from 1 to 12 hours, such as from 1.5 to 7.5 hours or from 2 to 6 hours.

[0075] In particular, the method for producing a glass-ceramic frit (especially a glass-ceramic frit of the present invention) further comprises a step of milling the glass-ceramic material. The milling step can be particularly carried out so that the grains have a particle size d50 in the range of 0.10 to 10 μm, e.g., 0.20 to 7.5 μm, 0.35 to 5.0 μm, 0.50 to 3.0 μm, or 1.0 to 1.5 μm.

[0076] In one aspect, the present invention relates to a method for producing a paste comprising a glass-ceramic frit (particularly a glass-ceramic frit of the present invention) and an organic medium. The organic medium may comprise or consist of, in particular, one or more glycol ethers, in particular 2-(2-butoxyethoxy)ethanol and / or 2-butoxyethanol. The organic medium may, for example, comprise or consist of 50-75% 2-(2-butoxyethoxy)ethanol and 20-30% 2-butoxyethanol.

[0077] The viscosity of the paste can be adjusted to suit the needs of the application.

[0078] In some embodiments, the weight ratio of glass-ceramic frit to organic medium in the paste ranges from 10:10 to 10:1, such as from 10:8 to 10:2 or from 10:6 to 10:3.

[0079] The method for preparing the paste may in particular comprise the step of mixing a glass-ceramic frit and an organic medium.

[0080] In one aspect, the present invention provides a method for producing a layer composite (particularly a layer composite of the present invention), comprising the steps of: a) coating a glass or glass-ceramic substrate with a paste comprising a glass-ceramic material (particularly the glass-ceramic material of the present invention) and / or a glass-ceramic frit (particularly the glass-ceramic frit of the present invention), wherein the paste further comprises an organic medium; b) heat treating (calcining) the coated substrate, in particular at a temperature between 600°C and 800°C and / or for a duration between 0.5 and 12 hours; The present invention relates to a method, comprising:

[0081] Heat treatment may also be called firing.

[0082] The coating step may in particular comprise screen printing. The screen mesh size may for example be at least 77 and / or at most 77, in particular 77-55T.

[0083] In some embodiments, the firing temperature is in the range of 400°C to 1000°C, e.g., 600°C to 800°C, 650°C to 950°C, 650°C to 850°C, or 650°C to 750°C. The firing temperature may specifically be at least 400°C, at least 500°C, at least 600°C, or at least 650°C. The firing temperature may specifically be up to 1000°C, up to 950°C, up to 850°C, up to 800°C, or up to 750°C.

[0084] In some embodiments, the baking time (duration) ranges from 0.5 to 12 hours, for example, from 1 to 9 hours or from 2 to 6 hours.

[0085] As mentioned above, the organic medium may in particular comprise or consist of one or more glycol ethers, in particular 2-(2-butoxyethoxy)ethanol and / or 2-butoxyethanol. The organic medium may, for example, comprise or consist of 50 to 75% 2-(2-butoxyethoxy)ethanol and 20 to 30% 2-butoxyethanol.

[0086] In some embodiments, the weight ratio of glass-ceramic frit to organic medium in the paste ranges from 10:10 to 10:1, such as from 10:8 to 10:2 or from 10:6 to 10:3.

[0087] In one aspect, the present invention relates to the use of the glass-ceramic material, the glass-ceramic frit, and / or the layer composite of the present invention, especially in household appliance or automotive applications, especially in the decoration of windshields.

[0088] Example The present invention is further illustrated by the following examples.

[0089] 1. Manufacturing of glass ceramic materials The mixed coarse batch composition was melted under a reducing atmosphere at above 1500°C but below 1650°C for about 30 to 120 minutes, followed by rapid cooling of the melt using a high-speed roller quench, water quench, or air quench, and the resulting glass ribbon was then sent for ceramming at ceramming temperatures ranging from 600°C to 850°C.

[0090] The glass-ceramic materials of the present invention were produced from different starting glass compositions using different ceramming profiles. The different ceramming profiles differed in terms of ceramming temperature and / or ceramming time. The following table provides an overview of Examples 1 to 17 by showing the starting glass compositions and the ceramming profiles applied thereto.

[0091] [Table 4]

[0092] The starting glass compositions (glass comp.) A, B, C, D, and E were as follows (wt %):

[0093] [Table 5]

[0094] The properties of glass compositions A to E are shown in the table below.

[0095] [Table 6]

[0096] 2. Characteristics of glass-ceramic materials The glass-ceramic materials obtained as described in the previous section were tested for their properties. In particular, the proportion of the main crystalline phase and the residual glass phase was determined. Furthermore, the crystallites of the main crystalline phase and the crystal size of each crystallite were determined. These results are summarized in the table below.

[0097] [Table 7]

[0098] The proportions of the main crystalline phase and the glassy phase were determined by X-ray diffraction analysis (XRD). The crystallite size of the main crystalline phase was determined by scanning electron microscopy (Zeiss Leo 1530 SEM) at an accelerating voltage of 20 kV. The range of crystallite size is shown with minimum and maximum values.

[0099] In most examples, the proportion of the main crystalline phase and the proportion of the glass phase totaled 100% by weight. This means that the main crystalline phase was the only crystalline phase in the glass-ceramic material. However, in Examples 6 and 7, the sum of the proportions of the main crystalline phase and the glass phase was less than 100% by weight. This is because there was an additional crystalline phase, the proportion of which was lower than the proportion of the main crystalline phase.

[0100] The predominant crystalline phase, crystallites, was (Fe,Mn)TiO3 for Examples 1-3, 6, 7, and 9-14, and (Fe,Mn)TiO4 for Examples 5, 8, and 15-17, as determined by X-ray diffraction analysis.

[0101] 3. Fabrication of glass-ceramic frit The glass-ceramic material was subjected to a grinding process to obtain a powder having a particle size d50 of approximately 1 to less than 5 μm, also called a glass-ceramic frit.

[0102] 4. Coating the substrate The glass ceramic frit (the milled powder described above) was used to prepare a paste for coating the substrate, and then the as-prepared paste was used to print samples by screen printing.

[0103] Various substrates were coated with a paste comprising the above-described glass-ceramic frit and an organic medium, which in particular comprised or consisted of one or more glycol ethers, in particular 2-(2-butoxyethoxy)ethanol and / or 2-butoxyethanol. After coating, the coated substrates were heat-treated to obtain an enamel coating layer.

[0104] The table below summarizes the substrate, coating conditions, and heat treatment details.

[0105] [Table 8]

[0106] The paste ratio indicates the weight ratio of glass-ceramic frit to organic medium in the paste used to coat the substrate. The screen mesh size indicates the mesh size of the screen used to coat the substrate with the paste. For the data underlying the table, a burn-in temperature of 680°C was applied during the heat treatment to obtain the enamel coating layer.

[0107] After heat treatment, a layer composite was obtained, including a substrate layer and an enamel coating layer.

[0108] 5. Properties of the Layer Composite The resulting layer composites were tested for optical and mechanical properties, and the results are summarized in Table 6 below. The gloss is measured from the side of the layer and / or coating.

[0109] [Table 9]

[0110] The optical density (opt. dens.) was determined with an X-Rite transmission densitometer model 361T according to ANSI PH2.19-1986, with the enamel coating layer facing upwards.

[0111] L in CIELAB color space * value, a * value, and b *The values ​​were determined using a KONICA MINOLTA spectrophotometer CM-700d according to the knowledge of a person skilled in the art, with the enamel coating layer facing upwards.

[0112] The gloss at 60° was determined by a RHOPOINT gloss meter according to known methods. The gloss is given in "Gloss Units" (GU). The measurement was carried out from the coating side, as described above.

[0113] The results show that durable coatings with good opacity were obtained.

[0114] Further examples are provided in the further tables, which may be considered to be particularly advantageous examples for the applications of the glass-ceramic materials and / or frits described herein.

[0115] Table 7 lists examples of glass-ceramic materials and property values ​​that can be beneficially achieved by the present invention that are particularly advantageous for dead-front applications in household devices. For dead-front applications, a relatively low haze is generally desirable. As can be seen from Table 8, the ceramming temperatures are at the lower end of the range. As a result, the ilmenite crystalline phase and / or ilmenite solid solution have crystal sizes at the lower end of the ranges mentioned above.

[0116] [Table 10]

[0117] [Table 11]

[0118] Table 8 lists examples of glass-ceramic materials and / or glass frits according to the invention, which are further processed into pastes and applied as coating layers and thus as layer composites for dead-front applications. In Tables 7 and 8, the gloss was measured from the substrate side.

[0119] [Table 12-1]

[0120] [Table 12-2]

[0121] Table 9 lists examples of glass compositions that can be used specifically for glass frits with high optical density and properties that can be beneficially achieved with the material system described herein. Compared to Table 8, the ceramming temperature for this application is higher, as shown in Table 10. Consequently, larger crystal sizes are achieved for the ilmenite and / or ilmenite solid solution phases, thereby resulting in higher optical densities.

[0122] [Table 13]

[0123] [Table 14]

[0124] Again, in this table, gloss is measured from the observer side, that is, from the substrate side through the substrate, in particular the glass substrate.

[0125] Table 10 lists examples of glass-ceramic materials according to the present invention, which are further processed and applied as frits with high optical density.

[0126] [Table 15-1]

[0127] [Table 15-2]

[0128] Table 11 lists examples of glass compositions for glass-ceramic materials and / or glass frits according to the present invention that can be used as coloring additives, particularly additives for coloring pastes and / or other glasses or glass ceramics. Table 12 shows examples of such additives. When such additives according to the present invention are incorporated as coloring additives and / or pigments into conventional decorative glass compositions and / or frits, the appearance and / or optical density of the black color can be beneficially improved. As can be seen from Table 12, the ceramming temperature of the additives according to the present invention is even higher than for other applications, thereby producing a greater amount of ferropseudobrookite phase, which leads to a further increase in optical density.

[0129] [Table 16]

[0130] [Table 17]

[0131] In this Table 12, gloss was measured from the observer side.

[0132] The presence of reference ilmenite and / or ilmenite solid solution phases was investigated by XRD measurements. Figure 1 shows the reference XRD diagram for a probe containing Fe, Ti, and Mn within the stated ranges, cerammed at 600 °C for 6 hours. The presence of solid solutions containing (FeMn)TiO3 and (FeMn)TiO4 is evident based on the reference XRD peaks.

[0133] Figure 2 shows the XRD diagram for a probe containing the above ranges of Fe, Ti, Mn, and Bi cerammed at 600 °C for 6 hours. The (FeMn)TiO3 and BiMnO3, as well as the metallic Bi phase, can be distinguished by their reference peaks. Thus, when we refer to colloids in this specification, we mean the metallic phase as well as the elemental phase.

[0134] Figure 3 shows an SEM (scanning electron microscope) of the probe described with reference to Figure 1. The (FeMn)TiO3 crystals are embedded in a darker glass matrix and have needle-like structures, the major diameter of which is measured using image processing software.

[0135] The present invention offers the advantage of providing a material in the form of a glass-ceramic and / or glass frit that can be applied by conventional tempering processes and thus has a very high optical density and a beneficially black appearance that can be applied to a wide variety of applications, particularly for household appliances such as stoves and / or automotive applications such as windshields, etc. The optical appearance can be easily manipulated by temperature processing. [Brief explanation of the drawings]

[0136] [Figure 1] FIG. 1 shows a reference XRD for a probe containing Fe, Ti, and Mn cerammed at 600° C. for 6 hours. [Figure 2] FIG. 1 shows an XRD for a probe containing Fe, Ti, Mn, and Bi cerammed at 600° C. for 6 hours. [Figure 3] FIG. 2 shows an SEM (scanning electron microscope) of the probe described with reference to FIG. 1.

Claims

1. 1. A glass-ceramic material comprising a glass phase in a proportion of at least 80.0 wt. % and a crystalline phase in a proportion of at least 0.1 wt. %; the crystalline phase comprising a main crystalline phase in a proportion of more than 50 wt. % compared to the total weight of the crystalline phase; and the main crystalline phase having an ideal formula Fe １－ｘ M ｘ TiO ３ or the formula (Fe １－ｘ , M ｘ ) ２ TiO ４ or (Fe １－ｘ , M ｘ ) Ti ２ O ５ wherein M is selected from the group consisting of Mn, Mg, Ni, Co, Zn, Cu, Cr, and combinations of two or more thereof, and x is in the range of 0 to 0.

80.

2. 2. The glass-ceramic material of claim 1, wherein M is selected from the group consisting of Mn, Mg, and combinations thereof.

3. 3. The glass-ceramic material according to claim 1, wherein the crystallites have an average crystal size, measured according to the specification, in the range of 0.1 to 5.0 μm.

4. Bi ２ O ３ , CeO ２ , V ２ O ５ , MoO ３ , W.O. ３ 4. The glass-ceramic material according to claim 1, further comprising a coloring oxide selected from the group consisting of:

5. 5. The glass-ceramic material of claim 4, wherein the coloring oxide is present in colloidal form.

6. 5. The glass-ceramic material according to claim 4, wherein the coloring oxide is present in a content of less than 2% by weight or less than 1% by weight.

7. A glass-ceramic frit comprising grains of a glass-ceramic material according to at least one of claims 1 to 6.

8. The glass-ceramic frit of claim 7, wherein the grains have a particle size d50 ranging from 0.35 μm to 5.0 μm.

9. 10. A layer composite comprising a glass or glass-ceramic substrate layer and an enamel coating layer, the enamel coating layer being obtained from a paste comprising a glass-ceramic material according to at least one of claims 1 to 6 and / or a glass-ceramic frit according to at least one of claims 7 and 8, the paste further comprising an organic medium and / or a color pigment.

10. 10. The layer composite of claim 9, wherein the thickness of the enamel coating layer is in the range of 1.0 to 30.0 μm.

11. 11. The layer composite according to claim 9, having an optical density in the range of ≧0.6 to <3 for light having a wavelength of 400 to 750 nm.

12. When measured at a reference thickness of the enamel coating layer of 7 μm, the L ＊ The coordinates are in the range of 1 to 80, preferably 20 to 80, and the a ＊ The coordinates are in the range of -15 to 20 and / or b ＊ 12. The layer composite according to claim 9, wherein the coordinates are in the range 0-25.

13. 13. The layer composite according to claim 9, wherein the gloss at 60° is in the range of from 60 GU to 110 GU, measured through the substrate.

14. 14. The layer composite according to claim 9, wherein the transmittance for light having a wavelength in the range of 380 to 740 nm is less than 8%, measured at a nominal thickness of the enamel coating layer of 7 μm.

15. 15. The layer composite according to claim 9, wherein the haze is in the range of 5 to less than 100.

16. 10. A method for producing a glass-ceramic material according to at least one of claims 1 to 6 and / or a glass-ceramic frit according to at least one of claims 4 and 5, comprising: a) providing a starting glass; b) ceramming said starting glass by heat treatment at a temperature between 500°C and 1000°C for a duration between 1 hour and 12 hours; A method comprising:

17. 16. A method for producing a layer composite according to at least one of claims 9 to 15, comprising the steps of: a) coating a glass or glass-ceramic substrate with a paste comprising a glass-ceramic material according to at least one of claims 1 to 6 and / or a glass-ceramic frit according to at least one of claims 7 and 8, wherein the paste further comprises an organic medium, b) heat treating the coated substrate at a temperature of 600°C to 800°C for a duration of 0.5 to 12 hours; A method comprising:

18. 16. Use of a glass-ceramic material according to at least one of claims 1 to 6, a glass-ceramic frit according to at least one of claims 7 and 8, and / or a layer composite according to at least one of claims 9 to 15 in the decoration of household appliances or automotive applications, in particular windshields.

19. 10. Use of the glass-ceramic material according to claim 1 as a pigment or coloring additive.

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