UV radiation-absorbing glass and uses thereof

Abstract

The present disclosure relates to a UV radiation-absorbing glass, preferably a soda-lime glass, comprising 0.08-0.2 wt% Fe2O3 and 0.4-1.4 wt% CeO2, wherein the sum of Fe2O3 and CeO2 is at least 1 wt%; and to uses of said glass. The present invention further relates to articles comprising the glass according to the present disclosure.

Description

DESCRIPTION UV-absorbing glass and its uses. TECHNICAL DOMAIN

[0001] This disclosure falls within the field of packaging materials used, for example, in the medical and food industries, with an emphasis on protection against UV radiation. Specifically, this disclosure refers to UV (ultraviolet) protective glass compositions designed for use in packaging containers, preferably for pharmaceutical and food products. BACKGROUND

[0002] UV radiation can negatively affect a variety of products, including: objects made of plastics and polymers, medicines, food products, textiles and fabrics, paintings and photographs, wood surfaces, electronic and optical devices, among others. Adopting effective protective measures is crucial to mitigate the adverse effects of UV exposure. A promising solution is the use of transparent glass with UV absorption capacity, which offers a wide range of benefits for various applications.

[0003] The advantages of this solution are numerous: UV absorption is the most important feature, as it allows the glass to act as a barrier against harmful UV radiation. This prevents the penetration of UV rays, protecting products against degradation, discoloration, and structural damage.

[0004] Using glass as a matrix is ​​fundamental to ensuring a low-cost solution, as UV-absorbing glass is more affordable than specialized coatings or treatments. Its reduced cost makes it a viable choice for a wide range and volume of applications, from packaging to museum displays. Transparent glass is highly recyclable, contributing to a circular economy. The recyclability of glass aligns with ecological practices and minimizes waste in production and disposal processes. Furthermore, the ability of glass to absorb UV radiation extends the lifespan of the products it protects, reducing the need for consumers to purchase replacements.

[0005] Transparency is also extremely important because it allows for the unimpeded display of products, preserving their visual appeal. This is particularly essential for works of art, photographs, and shop windows, where aesthetics play a critical role. Furthermore, in the case of food and pharmaceutical products, it increases packaging safety, as it facilitates the visual identification of undesirable changes. However, it is difficult to obtain glass that allows for adequate UV radiation absorption while maintaining a transparent appearance. Typically, packaging glass with adequate UV radiation absorption has an amber tint, which is less aesthetically appealing and can hinder the analysis of the product's appearance inside the container.

[0006] Solutions for the development of transparent packaging glass have already been explored. However, the development of intelligent solutions capable of alerting the user to excessive exposure to UV radiation, for example with a perceptible color change, would offer significant benefits. These would effectively warn consumers about prolonged and dangerous exposure to UV rays, addressing potential impacts on the product.

[0007] To impart UV absorption capacity and / or UV-induced color change to glass, various oxides can be incorporated into its matrix. Furthermore, in the pursuit of colorless glass, additional compounds can be strategically introduced. This approach aims to mitigate unwanted colorations in specific regions of the color space. By incorporating a compound or element that imparts a complementary or opposite color, the intention is to counterbalance and neutralize the initial coloration, thus contributing to the desired colorlessness of the glass. Examples of such elements include: Se, Cd, Co, Fe, Cu, Mn, Cr, Ni, etc.

[0008] The use of these elements generally leads to undesirable and / or excessive colorations in the glass and alters the intended physical properties, such as transparency, luminance, and structural integrity. Excessive concentrations of certain UV-absorbing additives, especially metal oxides, can cause color changes in the glass, which may be undesirable in applications where a transparent and colorless appearance is essential.

[0009] Document EP 1118597 Al describes a transparent and colorless soda-lime glass with ultraviolet radiation absorption capacity, intended specifically for containers for beverages and food products. The composition includes cerium oxide, iron oxides, and other color-adjusting agents, aiming to reduce UV-induced degradation without significantly compromising visible transmittance.

[0010] Document JP H10-218642 A discloses an ultraviolet radiation absorbing glass containing combinations of Fe2O3, CeO2 and TiO2, among other components typical of soda-lime glasses. The proposed solution aims to obtain glasses with optical properties tailored for architectural or automotive applications.

[0011] Document EP 1000910 BI refers to a glass with combined absorption of ultraviolet and infrared radiation, containing oxides of iron, cerium, titanium and, optionally, selenium and cobalt, particularly intended for applications in vehicle and building windows.

[0012] Document JP H06-345483 A describes a light gray soda-lime silica glass containing controlled levels of CeO2, TiO2, Fe2O3, CoO, and selenium.

[0013] Document EP 0 976 691 Al discloses a transparent soda-lime glass with reduced iron content and containing CeO2, TiO2, V2O5 and SO3, designed to exhibit ultraviolet transmittance below a certain limit and visible transmittance above a minimum value, while simultaneously maintaining a neutral tint.

[0014] These facts are described in order to illustrate the technical problem solved by the achievements of this document. GENERAL DESCRIPTION

[0015] This disclosure relates to a UV-absorbing glass, preferably a soda-lime glass, comprising 0.08–0.2% w / w of Fe2U3 and 0.4–1.4% w / w of CeO2, wherein the sum of Fe2U3 and CeO2 is at least 1% w / w; and to uses of said glass. This disclosure also relates to articles comprising the glass of this disclosure.

[0016] This disclosure addresses the need to preserve the integrity and safety of products by minimizing UV-induced degradation and photochemical reactions in sensitive substances, thereby extending their shelf life and preserving their quality.

[0017] This disclosure provides an optimized composition glass that achieves a balance between UV absorption and transparency using safe and stable components, particularly for use in contact with food and / or pharmaceutical compositions.

[0018] As used herein, "transparent" refers to the ability of glass to transmit at least 75% of visible light in the 400-700 nm range.

[0019] The glass in this disclosure exhibits improved UV absorption while maintaining high transparency in the visible spectrum, making it suitable for applications requiring protection and optical clarity. The controlled concentration of Fe2O3 ensures effective UV absorption without perceptible coloration, while CeO2 further enhances absorption in the UV range without significantly affecting visible light transmission.

[0020] The unexpected synergistic effect between these two oxides in the specified ranges leads to a substantial improvement in UV blocking efficiency compared to conventional compositions, while simultaneously maintaining a neutral aesthetic appearance and high optical clarity.

[0021] Finding the right balance in glass formulation ensures effective UV absorption while preserving the visual and mechanical characteristics that make the glass suitable for its purpose. This delicate optimization process allows for the creation of UV-blocking glass that effectively protects against harmful radiation without compromising the aesthetic and functional qualities of the material.

[0022] The UV-absorbing glass disclosed herein demonstrates versatility, serving a variety of purposes in architectural products, food or pharmaceutical containers, protection of textiles, fabrics, paintings, photographs, wood surfaces, and electronic / optical devices. The glass in question acts as a protective barrier against radiation, effectively reducing the risk of degradation, discoloration, and structural damage in these diverse applications.

[0023] The term "free" or "exempt," as used herein, refers to a glass composition containing an individual content of a specific component / element, in particular V2O5 and Mn2O3, below a detectable or functionally relevant threshold. In particular, this means that the total content of the element in question is below the detection limit of standard analytical techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES) or atomic absorption spectroscopy (AAS).

[0024] In a preferred embodiment, the glass of the present disclosure comprises a mixture of V2O5 and CeCh. Surprisingly, there was a synergistic relationship between V2O5 and CeCh, allowing for optimization of the glass's UV protection capabilities while meeting stringent compositional constraints. This mixture exhibits a synergistic effect that goes beyond the individual contributions of each component. Particular attention is given to the optical domain, where the interaction between V2O5 and CeCh influences parameters such as cutoff values, while simultaneously exhibiting appropriate coloration (AE variation relative to colorless and transparent glass less than 2.5).

[0025] In a preferred embodiment, the glass of the present disclosure comprises a mixture of Mn2O3 and CeO2. Surprisingly, Mn2O3 has been found to synergistically interact with CeO2, allowing for the optimization of the glass's UV protection capabilities while meeting stringent compositional constraints. This mixture exhibits a synergistic effect that goes beyond the individual contributions of each component. Particular attention is given to the optical domain, where the interaction between Mn2O3 and CeO2 influences parameters such as cutoff values, while simultaneously exhibiting appropriate coloration (equivalent composition glass with an AE variation, relative to colorless and transparent glass, of less than 2.5).

[0026] The results obtained showed the superiority of the glass in this disclosure, which combines the advantages of colorless glass (more appealing color and allows visual analysis of the product inside the glass container) with the advantages of amber glass (protection against UV radiation).

[0027] In terms of functional performance, the radiation cutoff value of the developed glass is superior to that of commercial colorless glass, providing effective protection against UV radiation.

[0028] Surprisingly, it was also discovered that the glass of the present disclosure, comprising a mixture of Mn2O3 and CeO2 or a mixture of V2O5 and CeCh, is a stability indicator glass and an indicator of the degree of exposure to UVA and UVB radiation. The developed glass was found to exhibit controlled solarization, with a well-defined mathematical color change during exposure to UVA or UVB radiation. Unlike amber glass and commercial colorless glass, which do not exhibit significant chromatic changes, the glass of the present disclosure stands out for its ability to change color upon exposure to UVA or UVB radiation. This particularity presents several advantages, especially allowing the evaluation and / or quantification of a given product's exposure to UVA or UVB radiation during its lifespan. Furthermore, it also has decorative applications, in addition to offering a dynamic aesthetic.

[0029] Notably, the color change in the glass of the present disclosure, induced by UV rays, even those exceeding a color difference (AE) above 8, can be effectively reversed through a 30-minute heat treatment close to the glass transition temperature (Tg), allowing the glass to be reused.

[0030] One aspect of the present disclosure relates to a transparent, UV-absorbing glass characterized by comprising: 0.05 to 0.2% w / w of FezCh; 0.4 to 1.5% w / w of CeCh.

[0031] In a preferred embodiment, the sum of FezChe CeChé is at least 0.5% m / m.

[0032] In a preferred embodiment, the sum of FezChe CeChé is at least 1% m / m.

[0033] In a preferred embodiment, the glass of the present disclosure may further comprise 0.1-0.8% w / w of V2O5; preferably 0.1-0.5% w / w.

[0034] In a preferred embodiment, the glass of the present disclosure may further comprise 0.1-1% w / w of Mn2O3; preferably 0.1-0.5% w / w.

[0035] In a preferred embodiment, the glass of the present disclosure may comprise 0.4 to 1.4% w / w of CeCh; preferably 0.4 to 1.3% w / w.

[0036] In a preferred embodiment, the glass of the present disclosure may comprise 0.4 to 1.2% w / w of CeCh; preferably 0.7 to 1.1% w / w.

[0037] In a preferred embodiment, the glass of the present disclosure may comprise 0.7 to 1.0% w / w of CeCh; even more preferably 0.8 to 1.0% w / w.

[0038] In a preferred embodiment, the glass of the present disclosure may comprise 0.08-0.2% w / w of FezCh; preferably 0.8-0.16% w / w.

[0039] In a preferred embodiment, the glass cutoff value may be greater than 330 nm; preferably greater than 350 nm; most preferably between 330-390 nm.

[0040] In a preferred embodiment, the glass of this disclosure may also comprise: 68 to 75% w / w of SiO2; 8 to 18% w / w of Na2O; preferably 8 to 15% w / w; 8 to 18% w / w of CaO; preferably 8 to 15% w / w; 0.1-4% w / w MgO; preferably 0.3 to 1.5% w / w; 0.1 to 2.5% w / w Al2O3; preferably 0.7 to 2% w / w; 0.1 to 3% w / w of K2O; preferably 0.4 to 2% w / w.

[0041] In a preferred embodiment, the color difference (AE) of the glass between an initial time (t=0 hours) and after 50 hours (t=50 hours) of exposure to UVA radiation at a power of 40 W can vary between 9-12; preferably 9-11.

[0042] In a preferred embodiment, the glass of the present disclosure may exhibit a visible light transmission of at least 75% at a thickness of 3.2 mm.

[0043] In a preferred embodiment, the glass thickness can vary between 1.5-4.0 mm; preferably 2.0-3.0 mm.

[0044] In a preferred embodiment, the glass may be free of V2O5 and Mn2O3.

[0045] In a preferred embodiment, the glass may be soda-lime glass.

[0046] One aspect of this disclosure relates to a glass article comprising glass as described in this disclosure.

[0047] In a preferred embodiment, the item may be selected from: packaging (preferably food and / or pharmaceutical grade), architectural glass, automotive glass, protective glass for paints or fabrics, optical lenses, or safety glasses; preferably packaging glass (preferably food or pharmaceutical grade).

[0048] In a preferred embodiment, the article may be a container, a bottle, a jar, a flask, or an ampoule.

[0049] In a preferred embodiment, the container may comprise a beverage or a medicine.

[0050] One aspect of this disclosure relates to the use of the glass in this disclosure as a stability indicator; in particular, as a stability indicator for solutions; more specifically, for beverages or pharmaceutical solutions.

[0051] In a preferred embodiment, the glass can be used as an indicator of exposure to UVA and / or UVB radiation; in particular, as an indicator of exposure to UVA and / or UVB radiation for solutions; more specifically, for beverages or pharmaceutical solutions. BRIEF DESCRIPTION OF THE FIGURES

[0052] For easier understanding, the figures are attached, which represent preferred embodiments and are not intended to limit the scope of this description.

[0053] Figure 1: Spectrophotometric transmittance of the glass in prototype 1 compared to commercially available colorless translucent glass (flint glass).

[0054] Figure 2: Spectrophotometric transmittance of the glass in prototype 2 compared to commercial colorless translucent glass (flint glass).

[0055] Figure 3: Degradation of carmine red dye stored in three different types of bottles: amber, colorless translucent (flint), and prototype 1 of this disclosure, exposed for up to 50 hours to UVA radiation (peak at 365 nm).

[0056] Figure 4: Degradation of carmine red dye stored in three different types of bottles: amber, colorless translucent (flint), and prototype 2, exposed for up to 50 hours to UVB radiation (peak at 312 nm).

[0057] Figure 5: Evolution of cora* and b* parameters up to 50h of UVA exposure for glass 1, glass 3 and prototype 1.

[0058] Figure 6: Evolution of color parameters a* and b* up to 50h of UVB exposure for glass 4, glass 6 and prototype 2, through UVB exposure.

[0059] Figure 7: Color difference or AE up to 50h of exposure to UVA radiation for commercial flint glass, glass 3 and prototype 1. DETAILED DESCRIPTION

[0060] This disclosure relates to a UV-absorbing glass comprising 0.08–0.2% w / w of FeO and 0.4–1.5% w / w of CeO2, wherein the sum of FeO and CeO2 is at least 1% w / w; and to uses of the glass thereof. This disclosure also relates to articles comprising the glass of this disclosure.

[0061] By cutoff value, we mean the wavelength at which the transmittance of the material decreases sharply, effectively blocking radiation below that limit. As an example, a cutoff of 370 nm means that wavelengths below 370 nm are largely absorbed or blocked, while wavelengths above that limit are mostly transmitted.

[0062] In the state of the art, color can be measured by various methods. In this disclosure, color was measured using the CIEL4B system (or CIE L*a*b*). L* is the luminance value (not influenced by hue or saturation), the chromatic coordinate a* corresponds to the green-red colors (where negative values ​​tend to correspond to green and positive values ​​tend to correspond to red), and the chromatic coordinate b* corresponds to the blue-yellow colors (where negative values ​​tend to correspond to blue and positive values ​​tend to correspond to yellow).

[0063] For the glass matrix of the materials in this disclosure, soda-lime glass was chosen due to its widespread use in various industrial applications, notably in glass panes and glass packaging, perfectly aligning with our specific objectives. The typical composition of soda-lime glass without additional UV protection includes the following components: SiO2 - 70 to 75% w / w; Na2O - 12 to 18% w / w; K2O - 0 to 1% w / w; CaO - 4 to 15% w / w; MgO - 0 to 4% w / w; Al2O3 - 0.5 to 2.5% w / w.

[0064] Additional minor constituents may be present to impart specific properties, such as colorants, bleaching agents, and opacifiers.

[0065] In this disclosure, novel glass formulations have been developed with the aim of achieving a colorless or nearly colorless appearance, while also incorporating UV absorption and UV-induced color change properties. UV-induced color changes serve as an indicator of prolonged exposure to UV radiation. This glass composition incorporates one or more oxides, possibly supplemented by one or more color-manipulating elements. The resulting glass can be molded into various shapes, meeting a wide range of applications. To evaluate its UV protective efficacy, tests were conducted with dyes inside containers made from one of the developed soda-lime glasses. The kinetic rates of color change were examined.

[0066] The base composition includes 68 to 75% w / w SiO2, 8 to 15% w / w by weight Na2O, 8 to 15% w / w by weight CaO, 0.3 to 1.5% w / w by weight MgO, 0.7 to 2% w / w by weight Al2O3 and 0.4 to 2% w / w by weight K2O, with CaO+MgO ranging from 6 to 15% w / w by weight and Na2O+K2O from 10 to 20% w / w by weight. UV absorbers should include one or more of the following: zinc oxide, titanium oxide, cerium oxide, iron oxide and vanadium oxide, with a cumulative amount of 0.5 to 3% by weight.

[0067] The colorants, including SeO2, CdO, CoO, Fe2O3, CuO, MnO2, Cr2O3, and NiO, may be present cumulatively or individually, with a total iron (Fe2O3) content between 0.05 and 0.2% w / w by weight.

[0068] Table 1 details the preferred quantities of ingredients in the mixture of essential raw materials for the preparation of colorless glass compositions according to the principles of the present invention.

[0069] Table 1: EXAMPLE 1 - UV-absorbing soda-lime glass comprising 0.83 to 4.83% w / w of CeO2 and 0.16% w / w of Fe2U3.

[0070] In one embodiment, the glass samples from examples 1F-1K in Table 2 were obtained.

[0071] Table 2 provides a detailed overview of the transformative impact resulting from the combined integration of Fe2U3 and CeO2 in the glass formulation. This collaborative approach aims to synergistically improve the overall performance of the glass, with a specific focus on key parameters, including cutoff values ​​and color gain assessed through delta E. These parameters serve as crucial metrics for evaluating glass performance in applications requiring precise control over light transmission and color fidelity.

[0072] Surprisingly, it was found that example 1F, comprising 0.8% w / w CeO2 and 0.16% w / w Fe2U3, achieved a cutoff value of 370 nm, representing a significant improvement over commercial colorless glass, which has a cutoff point at 330 nm. At the same time, this example has an AE (compared to an unaltered colorless and transparent commercial glass) of 1.49, considerably lower than the established limit of 2.5.

[0073] Table 2. Composition (main components) of examples 1F-1K comprising Fe3O3 and CeÜ2. >> < < < "" EXAMPLE 2A - UV-absorbing soda-lime glass comprising 0.7 to 1.4% w / w of CeO2 and 0.11% w / w of V2O5

[0074] In one embodiment, a soda-lime glass was obtained that is colorless or exhibits a very low color difference (AE < 3). This glass is distinguished by its composition, which includes a mixture of basic glass components, one or more colorants, 0.90% w / w CeCh and 0.10% w / w V2O5.

[0075] The composition of example 2A is summarized in Table 3, which highlights the presence of 0.890% w / w of CeCh and 0.111% w / w of V2O5. This table presents the values ​​obtained by XRF (X-ray fluorescence). The XRF technique measures the relative concentration of metallic species in the sample, with the oxides estimated by molar balance.

[0076] Table 3. Composition (main components) of the glass in example 1 of this disclosure. The present table was obtained by XRF measurements on glass samples from prototype 1. EXAMPLE 2B - UV-absorbing soda-lime glass comprising 0.1-0.5% w / w V2Os and 0.5 to 0.9% w / w CeO2.

[0077] Table 4 below presents seven additional examples of glass comprising V2Os and CeO2.

[0078] Table 4. Composition of glass with ceria oxide (CeO2) and vanadium oxide (V2Os) >> >> < < < "" * Measured on 3.2 mm thick glass

[0079] Surprisingly, V2O5 was found to synergistically collaborate with CeCh, with the cumulative amount of V2O5 and CeCh absorbers equal to or less than 1.0% w / w and the cumulative amount of UV absorbers (e.g., V2O5, CeCh, Fe2Ü3, M^Ch) carefully controlled to be below 1.5% by weight. This strategic combination, as presented in Examples 2B1-2B7, allowed for the optimization of the glass's UV protection capabilities while meeting stringent compositional constraints. Table 4 systematically details the impact of V2O5 along with other UV absorbers, particularly CeCh, resulting in the glass formulation achieving a synergistic effect that goes beyond the individual contributions of each component. Particular attention is given to the optical domain, where the interaction between V2O5 and other UV absorbers influences parameters such as cutoff values ​​(equal to or greater than 372 nm).The results outline the cumulative impact on the glass's ability to selectively absorb and attenuate UV radiation, thereby strengthening its UV protection characteristics.

[0080] Several elements can actively contribute to color induction in the soda-lime glasses in question. The overall concentration of iron oxide, as well as the FeO / Fe2O3 ratio, must be taken into account in order to mitigate the induction of yellow (Fe2O3) and / or blue (FeO) colors. The ratio between oxide species with different possible oxidation states, and potential for color induction, i.e., transition metals and rare earths, is significantly affected by the ratio between alkali / alkaline earth species and glass network formers, in this case represented by the SiO2 concentration. The higher the ratio, the lower the optical basicity of the glass and, consequently, the greater the probability that the species will be in more reduced states. NBO = [SiO2] + [B2O3] + [Al2O3] + [P2O5] - (4 x [SiO2] + 6 x [P2O5] + 3 x [B2O3] + oxygen modifiers) The formula estimates the number of non-binding oxygens (NBO) in a glass lattice based on its composition. The first component adds the contributions of the different oxides to the overall oxygen balance. The second component subtracts the number of oxygens predicted for each lattice former. The contribution of modifiers adds additional non-binding oxygens, increasing the degree of depolymerization of the glass.

[0081] Some elements are widely used to control the redox state of the aforementioned elements as potential colorants. However, the most efficient approach to eliminate color perceptibility is based on the addition of elements that induce the formation of color centers with colorimetric coordinates opposite to those previously observed. However, the use of this approach tends to decrease the luminance of the glass and, if used extensively, tends to produce frosted / dull glass.

[0082] The elements used can induce a yellowish or bluish discoloration in the base glass composition; therefore, the use of cobalt (blue) and / or selenium (red) can be useful to mitigate, respectively, the possible colorations mentioned above. It is important to mention that selenium and cobalt have a high molar extinction coefficient and toxicity, and the concentrations indicated in Table 3 should be limited. Method for obtaining soda-lime glass from example 2 (2A and 2B)

[0083] Following an optional grinding step to increase homogeneity, a single-step mixing process combines all the components of the mixture before they are introduced into the furnace. The resulting glass products exhibit enhanced ultraviolet absorption, thanks to the incorporation of one or more UV-absorbing oxide species.

[0084] In the laboratory setting, the glass samples were made at 1500 °C in a closed platinum crucible for 2 hours.

[0085] In the pilot scale, the manufacturing process of the bottle / prototype began with the introduction of the powder (ground glass plus CeCh and V2O5) into the furnace, which was already at a temperature of 1350 °C. It took just over 2 hours for the raw materials to melt, forming the molten glass. At this point, the technician removes a portion of molten glass and molds it, beginning the glassblowing process with a mold.

[0086] On an industrial scale, other considerations must be taken into account, namely the density of oxides such as cerium oxide and their refractory nature. Ideally, the addition of oxides would be feasible through the addition of a frit containing them, rather than their powdered form, to minimize density problems. Oven dwell times also need to be optimized according to the oven's geometry and type of heating source. Tests on this scale have not been performed.

[0087] Figure 1 depicts the spectrophotometric transmittance of the glass in prototype 1 compared to commercially available colorless translucent glass (flint glass). Figure 1 shows both the transmission and, consequently, the absorption capacity of the glass compared to commercial flint glass (a colorless and translucent glass). The areas under the lines represent the amount of radiation not absorbed. Thus, in the UV range, the line should be as close to 0 as possible, as this will indicate total absorption. Figure 1 shows a glass containing 0.9% w / w cerium oxide and 0.1% w / w vanadium oxide (prototype 1). The graphs are presented in terms of transmittance and not absorption, as this facilitates the determination of the cut-off points.

[0088] As verified in the result shown in Figure 1, the glass of prototype 1 has a significantly higher "cutoff" value than commercial colorless glass. This increase in the cutoff translates into a substantial improvement in protection against UVA and UVB radiation, reducing the photochemical degradation of light-sensitive products, such as food and beverages, which contributes to the preservation of their organoleptic and nutritional properties over time.

[0089] Example 2B7 (prototype 1) of this disclosure, comprising 0.1% w / w vanadium oxide and 0.9% w / w CeCh, showed particularly surprising results (Figures 3 and 5). The cutoff point was 381 nm with a color gain (AE_ab* or AE) of 2.48, which is below the established limit of 2.5.

[0090] The graph in Figure 3 shows the degradation of the carmine red dye (lxlO -4Carmine (M, a dye used in commercial cider) was stored in three distinct types of bottles: amber, colorless translucent (flint), and prototype 1 of this disclosure, exposed for up to 50 hours to UVA radiation (peak at 365 nm). If the graph in Figure 1 were plotted in absorbance instead of transmittance, the area under the curve would indicate the amount of radiation absorbed. A larger area suggests greater radiation absorption. These areas can be integrated to observe the progression of absorption over time. This approach was applied to analyze the absorption spectra of water with carmine dye during exposure to UV rays (up to 50 hours). Spectra were collected and analyzed in terms of absorbance. Subsequently, the areas under the curves were integrated. Due to the degradation of the dye over time under radiation, less radiation is absorbed, resulting in a decrease in the integrated areas.These integrated areas were then plotted as a function of the duration of exposure to UV light. Prototype 1 was used to test UVA light (365 nm), while prototype 2 was used for UVB light (312 nm).

[0091] The values ​​are represented as percentages because it was assumed that at the beginning of the experiment (t = Oh), the area under the curve corresponded to 100% of the total area of ​​the dye. Subsequent areas were calculated relative to this initial value. As the dye degrades over time due to exposure to radiation, the area under the curve decreases proportionally. Thus, the percentage values ​​indicate the relative amount of dye remaining at each time point compared to the initial amount. This approach allows for a direct comparison of dye degradation over the duration of UV exposure.

[0092] As verified in the results of Figure 3, Prototype 1 exhibits significantly superior protection compared to commercial colorless glass in preserving the carmine red dye when exposed to UVA radiation, although it has a lower protection capacity than commercial amber glass. Furthermore, Prototype 1 has a less intense color compared to amber glass, a characteristic that may be advantageous in certain applications. The graph in Figure 5 shows the evolution of the color* and b* parameters up to 50h of UVA exposure for comparative glass 1 (0.5% w / w vanadium oxide), comparative glass 3 (0.5% w / w vanadium oxide and 0.5% w / w ceria oxide), and glass 2B7 (prototype 1) of this disclosure. Figure 5 uses UVA to induce solarization and utilizes various glasses (glass 1, glass 3, and prototype 1) with different proportions of vanadium oxide and ceria oxide.Figure 5 uses UVA to induce solarization and employs various glasses with different proportions of vanadium oxide and cerium oxide, one of which has the same proportion and quantity as prototype 1.

[0093] The following Table 5 describes the composition (main elements) of comparative glass 1, comparative glass 3 and glass 2B7 (prototype 1) of this disclosure. Table 5. Composition (main elements) of comparative glass 1, comparative glass 3 and glass 2B7 (prototype 1) of this disclosure. >> >> < < < ""

[0094] As verified in the results of Figure 5, surprisingly, the 2B7 glass (prototype 1) of this disclosure, in addition to having appropriate color and cut-off value, undergoes controlled solarization with exposure to UVA radiation. Therefore, the glass of this disclosure can be used as a stability indicator glass or a radiation exposure indicator glass. This characteristic presents several advantages, especially allowing the evaluation and / or quantification of a given product's exposure to radiation during its lifetime. Furthermore, it also has decorative applications and offers a dynamic aesthetic.

[0095] The CIELAB color space has 3 axes. Here we are ignoring the L* axis and representing only the a* and b* color coordinates in 2D. The color coordinates indicate their position between red and green (a*, where negative values ​​indicate green and positive values ​​indicate red) and their position between yellow and blue (b*, where negative values ​​indicate blue and positive values ​​indicate yellow). The points shown represent distinct exposure times to UV radiation (for each glass sample), and a line can be drawn between them, illustrating the trend of the glass color with exposure to UV radiation. By graphically representing these points, each corresponding to a specific exposure duration, it is possible to observe the trajectory of the color change over time. This line provides a visual representation of the evolution of the glass color as it is exposed to UV radiation.Additionally, markers such as 't0' and 't50' were included to indicate the start and end points of the exposure, helping to highlight the direction of the color change along the line.

[0096] Figure 7 shows the color difference or AE up to 50 hours of exposure to UVA radiation for commercial flint glass, comparative glass 3, and glass 2B7 (prototype 1) from this disclosure. In Figure 7, above the dotted line, the color of the glass samples differs significantly, enough to be considered a distinct shade / color. As explained earlier, AE is the color change of a glass. Here we measured the color change of three distinct glasses that exhibit solarization when exposed to solar / UV radiation, and a colorless commercial flint glass that remains unchanged. The graphical representation of AE throughout UV radiation exposure allows us to describe the kinetic behavior of color changes and justify the moments when AE reaches specific values.This is important because it helps to assess the color stability of materials and predict the exposure time required to induce detectable color changes, with AE values ​​above 2 being perceptible to all observers.

[0097] As verified in the results of Figure 7, the degree of color change can be mathematically represented over a 50-hour period of exposure to UVA light, allowing for precise modeling and quantification of the color change behavior. Thus, as mentioned above, the glass in this disclosure can be used as stability indicator glass or radiation exposure indicator glass. This feature offers several advantages, especially allowing for the evaluation and / or quantification of a given product's exposure to radiation during its lifespan. Furthermore, it also has decorative applications and offers a dynamic aesthetic. EXAMPLE 3 - UV-absorbing soda-lime glass comprising 0.1 to 1% w / w CeO2 and 0.1-0.5% w / w Mn2O3 - PROTOTYPE 2

[0098] Table 6 below presents 3 examples of glass comprising CeO2 and Mn2O3.

[0099] Table 6 >> >> < < < "" *measured on 3.2 mm thick glass

[0100] Figure 2 illustrates the spectrophotometric transmittance of the glass in prototype 2 compared to commercial colorless translucent glass (flint glass). This graph provides a visual representation of the advantageous UV-VIS transmittance properties of the described glass compositions, highlighting their potential to offer superior performance compared to conventional flint glass. Figure 2 shows both the transmission and, consequently, the absorption capacity of each glass compared to commercial flint glass (a colorless and translucent glass). The areas under the lines represent the amount of radiation not absorbed. Thus, in the UV range, the line should be as close to 0 as possible, as this will indicate total absorption. Figure 2 shows a glass containing cerium oxide and manganese oxide (prototype 2). A commercial colorless translucent glass is shown to highlight the improvements compared to the commercially available solution.The graph is presented in terms of transmittance, not absorption, because this makes it easier to determine the cut-off points.

[0101] As verified in the results of Figure 2, prototype glass 2 has a significantly higher "cutoff" than commercial colorless glass. This increase in cutoff translates into a substantial improvement in protection against UVA and UVB radiation, reducing the photochemical degradation of light-sensitive products such as food and beverages, which contributes to the preservation of their organoleptic and nutritional properties over time.

[0102] The graph in Figure 4 shows the degradation of the carmine red dye (lxlO -4M) stored in three distinct types of bottles: amber, colorless translucent (flint), and prototype 2, exposed for up to 50 hours to UVB radiation (peak at 312 nm). If the graph in Figure 2 were plotted in absorbance instead of transmittance, the area under the curves would indicate the amount of radiation absorbed. A larger area suggests greater absorption of radiation.

[0103] The values ​​are represented as percentages because it was assumed that at the beginning of the experiment (t=0 h), the area under the curve corresponded to 100% of the total area of ​​the dye. Subsequent areas were calculated relative to this initial value. As the dye degrades over time due to exposure to radiation, the area under the curve decreases proportionally. Thus, the percentage values ​​indicate the relative amount of dye remaining at each time point compared to the initial amount. This approach allows for a direct comparison of dye degradation over the duration of UV exposure.

[0104] As verified in the results of Figure 4, Prototype 2 offers significantly superior protection to commercial colorless glass in preserving the carmine red dye. Up to 30 hours of exposure to UVB radiation, Prototype 2 offers a level of protection equivalent to commercial amber glass. After this period, the amber glass reveals a slight advantage in its ability to absorb UVB radiation, providing marginally superior protection against dye degradation. Prototype 2 protects the carmine red dye better than commercial colorless glass and, up to 30 hours of exposure to UVB radiation, protects as much as commercial amber glass. After 30 hours of exposure, the amber glass is slightly superior in its ability to absorb radiation and thus protect against dye degradation.

[0105] The graph in Figure 6 shows the evolution of the color parameters a* and b* up to 50 hours of UVB exposure for glass 4, glass 6, and prototype 2, through UVB exposure. Since it is possible to draw a line through all points at the different times when the samples were measured with different UVA (for Fig. 5) and UVB (for Fig. 6), points t0 and t50 were added to indicate the direction of movement of the glass coordinates. Figure 6 uses UVB and has different proportions of cerium oxide with manganese oxide, one of which has the same formulation as prototype 2.

[0106] Figure 6 uses UVB to induce solarization and tests different glasses (prototype 2 of this disclosure, comparative glass 4 and comparative glass 6).

[0107] The following Table 7 describes the composition (main elements) of comparative glass 4, comparative glass 6 and prototype 2 of this disclosure. Table 7. Composition (main elements) of comparative glass 4, comparative glass 6 and prototype 2 of this disclosure. >> >> < < <

[0108] As verified in the results of Figure 6, prototype 2 undergoes solarization upon exposure to UVB radiation. However, glasses 4 and 6 do not undergo significant changes in the color parameters a* and b*. As verified in the results of Figure 6, surprisingly, prototype glass 2 of this disclosure, in addition to having an appropriate color and cut value, undergoes controlled solarization with exposure to UVA radiation. Therefore, the glass of this disclosure can be used as a stability indicator glass or a radiation exposure indicator glass. This feature offers several advantages, especially allowing the evaluation and / or quantification of a given product's exposure to radiation during its lifetime. Furthermore, it also has decorative applications and offers a dynamic aesthetic. MATERIALS AND METHODS Color

[0109] All color measurements were performed using the CIE Lab* color space and can be visualized in this three-dimensional space. This system uses three orthogonal axes. The vertical axis, called L*, describes the lightness values, with 0 representing black and 100 meaning white. The a* axis refers to the green-magenta / red spectrum, with negative values ​​for green and positive values ​​for magenta. In turn, the b* axis describes the blue-yellow spectrum, with negative values ​​corresponding to blue and positive values ​​to yellow.

[0110] To quantitatively measure the color difference (AE*ab or AE), the CIE Lab* color space was used. The AE* b It provides a value for the color difference between two pairs of samples with distinct experimental conditions, such as the presence of different UV-absorbing oxides, which can also influence color. The AE* formula b :

[0112] Where L* represents the difference in luminosity between the colors of the materials, a* represents the difference on the red / magenta / green axis, and b* represents the difference on the yellow / blue axis. The values ​​L*1, a*2, and b*1 correspond to the control sample – a colorless and transparent commercial glass that is not altered. On the other hand, the values ​​L*2, a*2, and b*2* correspond to the samples produced in the laboratory with different amounts of added oxides.

[0113] Since the ultimate goal is to obtain glass capable of protecting against radiation while remaining colorless and transparent, it is important that the AE*ab value remains low. To identify the most promising approaches, we focused on experiments that demonstrated favorable results in two critical parameters. These parameters were the wavelength cutoff point, which indicates the point at which transmission decreases to 50% of the pass rate, and the improvement in color quality, quantified by the color gain (AE*ab). However, to define a reference value for AE*ab, it was necessary to determine when color differences become perceptible. According to Mokrzycki et al., values ​​below 2 are perceptible mainly to trained observers, while values ​​above this limit become evident to untrained individuals.Thus, considering an AE*ab target of 2, a pragmatic compromise of 2.5 was chosen to also achieve a favorable cutoff point.

[0114] The term "comprises" or "comprising" when used in this document is intended to indicate the presence of mentioned features, elements, integers, steps, and components, but does not preclude the presence or addition of one or more other features, elements, integers, steps, and components, or groups thereof.

[0115] The terms "comprising," "comprising," and "composed of" used herein are synonymous with "including," "includes," or "contains," and are inclusive or open-ended, not excluding additional members, elements, or method steps not mentioned. The terms also encompass "consisting of" and "consisting essentially of," which have well-established meanings in patent terminology.

[0116] The present invention is, of course, in no way limited to the embodiments described in this document, and a person with average knowledge of the field could foresee many possibilities for its modification and for the substitution of technical features with equivalent ones, depending on the requirements of each situation, as defined in the appended claims.

[0117] The following claims define additional realizations of the present description. Bibliography: [1] HM Gomaa, HA Saudi, IS Yahia and HY Zahran, "Improved optical, electrical and shear properties of some alkali-borate glasses doped with lanthanide oxide, CeO2," J. Mater. Sci. Mater. Eletron., vol. 33, no. 6, pp. 3284-3296, Feb. 2022, doi:10.1007 / sl0854-021-07529-3. [2] Y. Jiang, L. Wang, W. Zhang, L. Teng, F. Hu, and H. Guo, "Dual-valence Ce doped UV-shielding glasses with high transparency and stability," Ceram. Int., vol. 46, no. 10, pp. 16032-16037, Jul. 2020, doi: 10.1016 / j.ceramint.2020.03.153. [3] R. K. Mishra, S. K. Avinashi, Shweta, S. Kumari, and C. Gautam, "Synergistic Effect of Fe2O3 Doping on Physical, Structural, Optical, and Radiation Shielding Characteristics of the Glasses in a System (30-x)BaO-30Ti02-40Si02-xFe203 (0 < x < 6) for Optoelectronic Applications," J. Inorg. Organomet. Polym. Mater., Oct. 2023, doi: 10.1007 / sl0904-023-02897-1. [4] S. P. Singh, R. P. S. Chakradhar, J. L. Rao, and B. Karmakar, "EPR, FTIR, optical absorption and photoluminescence studies of Fe2O3 and CeO2 doped ZnO-Bi2O3-B2O3 glasses," J. Alloys Compel., vol. 493, no. 1-2, pp. 256-262, Mar. 2010, doi: 10.1016 / j.jallcom.2009.12.075.

Claims

CLAIMS 1. Transparent UV-absorbing glass comprising: 0.05 to 0.2% w / w of Fe2Ü3; 0.4 to 1.5% w / w of CeO 2; 0, 1-0.8% m / m V2Ose / or 0.1-1% m / m Mn2O3; where the sum of Fe2U3 and CeO2 is at least 0.5% w / w.

2. Glass according to the previous claim, wherein the sum of Fe2U3 and CeO2 is at least 1% w / w.

3. Glass according to any of the preceding claims, further comprising 0.11-0.5% w / w of V2O5.

4. Glass according to any of the preceding claims further comprising 0.1-0.5% w / w of Mn2O3.

5. Glass according to the previous claim, comprising 0.4 to 1.4% w / w of CeO2; preferably 0.4 to 1.3% m / m.

6. Glass according to the previous claim, comprising 0.4 to 1.2% w / w of CeO2; preferably 0.7 to 1.1% w / w.

7. Glass according to the previous claim, comprising 0.7 to 1.0% w / w of CeO2.

8. Glass according to the previous claim, comprising 0.8 to 1.0% w / w of CeO2.

9. Glass according to any of the preceding claims, comprising 0.08-0.2% w / w of Fe2Os; preferably 0.8-0.16% w / w.

10. Glass according to any of the preceding claims, wherein the glass cutoff value is greater than 330 nm; preferably greater than 350 nm; more preferably between 330-390 nm.

11. Glass according to any of the preceding claims, which further includes: 68 to 75% w / w of SiO2; 8 to 18% w / w of Na2O; preferably 8 to 15% w / w; 8 to 18% w / w of CaO; preferably 8 to 15% w / w; 0.1-4% w / w of MgO; preferably 0.3 to 1.5% w / w; 0.1 to 2.5% w / w of Al2O3; preferably 0.7 to 2% w / w; 0.1 to 3% w / w of K2O; preferably 0.4 to 2% w / w.

12. Glass according to any of the preceding claims, wherein the color difference (AE) of the glass between an initial time (t=0 hours) and after 50 hours (t=50 hours) of exposure to UVA radiation at a power of 40 W varies between 9-12; preferably 9-11.

13. Glass according to any of the preceding claims, wherein the glass exhibits a visible light transmission of at least 75%.

14. Glass according to any of the preceding claims, wherein the thickness of the glass varies from 1.5-4.0 mm; preferably 2.0-3.0 mm.

15. Glass according to any of the preceding claims, wherein the glass is soda-lime glass.

16. Glass article, comprising glass according to any of the preceding claims.

17. Article according to the previous claim, where the article is selected from: Packaging, architectural glass, car glass, paint or fabric protective glass, optical lenses, or protective eyewear; preferably packaging glass.

18. Article according to any of claims 16-17, wherein the article is a container, a bottle, a jar, a flask, an ampoule.

19. Article according to claims 16-18, wherein the container comprises a beverage or a medicine.

20. Use of glass according to any of the preceding claims 1-15, as a stability indicator; in particular a stability indicator for solutions; more particularly for beverages or pharmaceutical solutions.

21. Use of glass according to any of the preceding claims 1-15, as an indicator of exposure to UVA and / or UVB radiation; in particular an indicator of exposure to UVA and / or UVB radiation for solutions; more particularly beverages or pharmaceutical solutions.

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