A glass composition and a glass article obtained therewith

Abstract

The present invention relates to a composition for glass articles, in particular for flat glass, glass packaging and household glass products. The glass composition of the invention has been developed within the SiO2-AI2O3-CaO-MgO-Na2O system and has superior mechanical and chemical durability. The composition comprises, in weight percent, 55-70 SiO2, 5-15 AI2O3, 5-15 MgO, 0-8 CaO, 5-18 Na2O and 0-4 B2O3.

Description

[0001] A GLASS COMPOSITION AND A GLASS ARTICLE OBTAINED THEREWITH

[0002] TECHNICAL FIELD

[0003] The present invention relates to a glass composition with reduced CO2emissions and improved material properties for glass articles, in particular for flat glass, glass packaging and household glass products and their manufacture.

[0004] BACKGROUND OF THE INVENTION

[0005] Glass articles are widely used in a variety of applications such as architecture, windows, automotive, packaging, storage, serving, presentation and decoration. Although such glass products belong to the conventional soda-lime silicate glass family, they commonly find use across a broad spectrum including windows, plates, sheets, automotive glazing, bottles, jars, tumblers, containers, vases, household ware, tableware, laboratory ware and decorative objects. Conventional glass-making employs techniques such as float, molding, blowing and casting. To produce a glass article, a mixture of raw materials — typically a batch — is fed onto the surface of an existing glass melt in a furnace. The mixture may comprise the batch and cullet (recycled glass). Cullet is obtained by breaking recycled glass bottles, jars, household glassware, flat glass and other glass types into small pieces. These materials are melted in melting furnaces operated at around 1500 °C to obtain glass.

[0006] The glass industry is a large, energy-intensive sector that emits a significant amount of greenhouse gases per unit mass of glass produced. According to the latest figures, approximately 100 million tonnes of CO2are released into the atmosphere annually due to glass manufacturing activities. Both the combustion of fossil fuels to provide the high-temperature environment required for melting and the thermal decomposition reactions of carbonate raw materials used in glass manufacture constitute the principal greenhouse gas emissions, especially CO2. The glass melting process produces 500-800 kg of CO2for every 1 tonne of glass produced, making it one of the production processes with the highest CO2emissions worldwide. For every 1 tonne of glass produced, approximately 210 kg of CO2is released solely from the raw materials used (Figure 1 ). In other words, depending on the usage rates of carbonate raw materials, the CO2emissions released by the decomposition reactions of the raw materials correspond to about 21 wt.% of the mass of each unit mass of glass produced. Therefore, roughly one-third of the CO2emissions associated with glass manufacture are due to decomposition of raw materials, and approximately two-thirds arise from consumption of fossil fuels. To modify glass manufacturing into an environmentally friendly process, innovative techniques are needed in both the raw-material / batch systems and in energy systems. Hence, to enable the glass industry to combat the climate crisis and align with net-zero strategies, new methods must be developed and adapted to the current process.

[0007] To this end, a new glass composition has been developed that allows lower CO2release, is environmentally friendly, and possesses superior material properties. The invention covers innovative glass compositions that provide a 42-76% reduction in carbon dioxide (CO2) emissions arising from melting reactions in glass production, while simultaneously improving material properties and optimizing melting and fining processes.

[0008] EP2958866B1 relates to energy-efficient soda-lime silicate glass compositions in which borax pentahydrate is used. In particular, the invention pertains to increasing the boron oxide content by using borax pentahydrate as a raw material in the production of different industrial glasses mentioned above. In this approach, a simultaneous substitution is achieved by replacing soda ash as the Na2O source with the Na2O contained in borax pentahydrate. A glass composition containing, in weight percent, 22.68-74.62 SiO2, 28.5-30.3 B2O3, 13.0-23.5 Na2O, 0.0- 10.5 CaO, 0.03-0.3 K2O, 0.15-1 .3 AI2O3, 0.43-4.0 MgO and 0.05-0.12 Fe2O3+TiO2, and AI2O3is disclosed.

[0009] EP4493526A1 relates to low-temperature glass production with a glass composition containing, in mole percent, 25-55 P2O5, 5-45 SiO2, 5-22 AI2O3, 5-30 ZnO, 0-20 Na2O, K2O, Li2O, and 2-8 CaO, MgO.

[0010] BRIEF SUMMARY OF THE INVENTION

[0011] The object of the invention is to provide glass composition within the SiO2-AI2O3-MgO-Na2O system with low carbon dioxide (CO2) emissions and enhanced product properties, and a glass article obtained therefrom.

[0012] In order to achieve above objective, the invention provides a glass composition for a glass article, particularly for hollow glass. The glass composition comprises, in weight percent (wt.%): 55-70 SiO2, 5-15 AI2O3, 5-15 MgO, 5-18 Na2O, preferably 6-16 Na2O, more preferably 6- 15 Na2O, 0-8 CaO, preferably 2-8 CaO, more preferably 3-8 CaO, and 0-4 B2O3. In this way, in the composition that falls within the given ranges, the high proportions of SiO2and AI2O3components in the resulting glass increase the structural integrity of the glass and provide resistance to cracking and breakage. The addition of MgO, CaO, Na2O and B2O3components in varying proportions facilitates melting and forming / processing of the glass while allowing the material properties to remain within desired ranges.

[0013] Accordingly, in the composition within the specified ranges, the network-forming oxides SiO2and AI2O3are present at high proportions in the resulting glass, increasing network connectivity and providing resistance to mechanical and chemical effects. Adding MgO, CaO, Na2O and B2O3to the composition in varying proportions facilitates melting and forming of the glass to obtain glass articles, while allowing various material properties to remain within desired ranges.

[0014] Glass manufacture is a challenging process carried out at high temperatures and requires precise management of a viscous melt both within the furnace and in forming equipment. The viscosity of the glass in the molten state varies with its composition, i.e., chemical makeup, and directly affects production conditions (melting temperature, melting time, glass quality, forming time, etc.), thereby determining total energy consumption and time. The invention is configured to provide the standard thermal properties expected in glass melting and forming processes (viscosity regime, crystallization temperature).

[0015] In a preferred embodiment, the melting temperature of the glass is on average around 1450 °C, and the viscosity regime is at levels similar to conventional glass compositions.

[0016] In a preferred embodiment, the viscosity regime of the glass exhibits behavior similar to conventional glass compositions, thereby making it compatible with existing production techniques.

[0017] In a preferred embodiment, the SiO2content is 57-68 wt.%, preferably 58-65 wt.%. Thus, SiO2as the principal network former increases glass strength.

[0018] In a preferred embodiment, the AI2O3content is 6-13 wt.%, preferably 6-10 wt.%. In this way, the mechanical strength of the glass is significantly increased, thereby reducing the likelihood of cracking and breakage. AI2O3also enhances the chemical durability of the glass, improving its resistance to various chemicals and corrosive environments. By increasing wear resistance, AI2O3enables a long-lasting and durable material, extending service life and helping reduce consumption volumes.

[0019] In a preferred embodiment, the CaO content is 1-6 wt.%, preferably 4-7 wt.%. In this way, properties such as glass viscosity, forming behavior, mechanical and chemical durability, density, refractive index and thermal expansion can be set to desired values while crystallization resistance can be controlled.

[0020] In a preferred embodiment, the MgO content is 6-13wt.%, preferably 8-12 wt.%. In this way, properties such as viscosity, forming behavior, mechanical and chemical durability, density, refractive index and thermal expansion can be set to desired values while crystallization resistance can be controlled.

[0021] In a preferred embodiment, the Na2O content is 8-17wt.%, preferably 8-14 wt.%. In this way, Na2O lowers the viscosity and melting point of the glass, making the production process more energy-efficient.

[0022] In a preferred embodiment, the B2O3content is 0-3 wt.%. Thus, B2O3lowers the viscosity, provides easier processability during production and increases production efficiency. It also reduces the melting temperature of the glass, saving energy during production and lowering production costs.

[0023] In a preferred embodiment, the Fe2O3content is 0-1 wt.%. In this way, the glass can be produced in the desired target colors (e.g., colorless, green or amber). In a preferred embodiment, the Cr2O3content is 0-1 wt.%. In this way, glass can be produced in desired target colors (e.g., green). In a preferred embodiment, the K2O content is 0-1 wt.%. In this way, chemical, optical and mechanical properties are optimized to obtain a high-performance, durable and aesthetically superior material. In a preferred embodiment, the SO3content is 0- 1 wt.%, in particular 0-0.5 wt.%. The fining agent SO3is preferably added as Na2SO4, and the amount used is determined according to the target product color and quality. In a preferred embodiment, the TiO2content is 0-1 wt.%. To achieve the stated objective, the invention further provides a glass obtained with a glass composition according to any of the embodiments above.

[0024] In a preferred embodiment, the difference between the gob (dropping) temperature T3and the crystallization (liquidus) temperature Tliq is at least 35 °C. Thus, crystallization risk is prevented while cooling the glass to the forming temperature, enabling sustainable high-yield production.

[0025] In a preferred embodiment, the decomposition reactions of the raw materials used to obtain the glass generate, on average, half the emissions (-50-120 kg CO2 / tonne glass) compared with the CO2emissions (-210 kg CO2 / tonne glass) of conventional batches. Thus, a 42-76% reduction in emissions from decomposition reactions can be achieved. In a preferred embodiment, laboratory examinations have determined that, when using the same amount of fining agent (sodium sulfate) as in conventional batches, fining of the glass occurs in a shorter time, which can contribute positively to reducing energy-related emissions.

[0026] In a preferred embodiment, the Young’s modulus of the obtained glass is at least 74 GPa. In this way, mechanical robustness enables the production of thinner-walled corrugated glass products. As a result, glass products can be manufactured with thinner walls, reducing the CO2emissions per unit of glass produced.

[0027] In a preferred embodiment, the chemical durability of the glass obtained from prototype products is better than that of current glassware products; it falls within class HGB 3 under ISO 719 and within class HCT B under ISO 4802. Thus, it offers safe use and long service life both under conventional use conditions and, in food and liquid contact, in more aggressive environments.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an example graph showing the measurement of gases released as a result of reactions occurring from heating the raw material mixture used for traditional glass production.

[0030] Figure 2 is a comparative graph showing how the viscosities of a conventional soda-lime silicate glass and the glass of the present invention vary with temperature.

[0031] Figure 3 shows images obtained from experiments relating to fining examinations of a conventional soda-lime silicate glass and the glass of the present invention.

[0032] Figure 4 provides calculated Young’s modulus values of example glasses of a conventional soda-lime silicate glass and of the present invention.

[0033] Figure 5 shows images of trial specimens produced as prototypes targeting the glass composition of the invention.

[0034] Figures 6A and 6B show, respectively according to ISO 719 and ISO 4802 methods, the hydrolytic durability values of a conventional soda-lime silicate glass and of the glass of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] In this detailed description, the invention is described without limitation and only with references to examples to better explain the subject matter.

[0036] Standard glass products and glassware (flat glass, glass packaging, windows, plates, sheets, bottles, jars, household ware, tumblers, goblets, containers, vases, laboratory ware, etc.), in particular standard hollow glass products, are manufactured with compositions in the sodalime silicate glass family and contain approximately, by weight, 68-72 % SiO2, 0-2 % AI2O3, 0- 4 % MgO, 8-10 % CaO, 13-15 % Na2O, 0-1 % K2O and other minor oxides (Fe2O3, TiO2, Cr2O3, SO3). These glass articles and products are obtained industrially by melting, at high temperature in industrial-scale glass furnaces, a mixture called the batch formed by combining, in certain proportions, the principal raw materials of sand, feldspar, limestone, dolomite and soda ash. During melting, as the temperature of the batch components increases, the carbonate raw materials limestone (CaCO3), dolomite (CaMg(CO3)2) and soda ash (Na2CO3) undergo thermal decomposition, releasing the CO2gas in their structures and emitting it to the atmosphere, thereby contributing to the greenhouse effect. The details of these reactions are as follows:

[0037] Limestone: CaCO3— > CaO + CO2. The reaction occurs in the range of -900-970 °C and releases CO2with a mass approximately equal to 44 wt.% of the mass of the limestone.

[0038] Dolomite: CaMg(CO3)2— > CaO + MgO + 2 CO2. The reaction occurs in the range of -685- 700 °C and releases CO2with a mass approximately equal to 48 wt.% of the mass of the dolomite.

[0039] Soda ash: Na2CO3— > Na2O + CO2. The reaction occurs at -850 °C and releases CO2with a mass approximately equal to 41 wt.% of the mass of soda ash.

[0040] Depending on the usage proportions of the specified raw materials in glass production, during melting of the raw materials, CO2gas is released by decomposition reactions amounting to approximately 21 wt.% of each unit mass of glass produced. In other words, for every 1 tonne of glass produced, approximately 210 kg of CO2is released solely from the raw materials used. Figure 1 shows an exemplary graph of the gases released as measured upon heating the raw-material batch used for conventional glass production and the reactions occurring. Here, intensive CO2is released as a result of progressive decomposition reactions beginning at approximately 600 °C, 700 °C and 850 °C for dolomite, limestone and sodium carbonate, respectively, which are present in the raw-material mixture called the batch. The area under the curve in the graph represents the total amount of CO2released during the melting process; for conventional soda-lime silicate glass batches, this value is -210 kg CO2 / tonne glass. Furthermore, to ensure homogenization of the glass melt formed as a result of the reactions and to remove gaseous inclusions (fining) existing in the glass melt due to decomposition reactions, the glass melting furnace must be operated at high temperatures (-1500 °C) and the melt must be held in the furnace for long periods. The energy required for this is supplied by consumption of fossil fuels, primarily natural gas. Accordingly, for every 1 tonne of glass produced, approximately 300-500 kg of CO2is released due to consumption of fossil fuels.

[0041] In connection therewith, the glass composition of the invention enables the use of smaller amounts of raw materials that release CO2. In addition, the amount of CO2released is directly proportional to the weight of the glass produced; therefore, lower consumption will also result in reduced greenhouse gas emissions. While meeting the demand for current glassware, the principal way to reduce total glass production and consumption is to manufacture lighter glass products. For this purpose, products must be thinned for weight-reduction; however, no adverse impact on mechanical performance is desired. To this end, a glass composition has been developed in which, together with mechanical strength, other material properties are also improved. The present invention thus provides a glass composition that enables reduction of CO2released in glass production and has improved material properties.

[0042] There are several critical properties and value ranges of glass products that must be monitored and controlled in terms of process and performance. The principal ones include viscosity, forming (working) range, crystallization resistance, mechanical and chemical durability, density, refractive index, and coefficient of thermal expansion. The importance of these critical properties and of glass production technologies is detailed below in order to explain the innovative and improved aspects of the invention.

[0043] Viscosity. Viscosity is a dynamic concept of critical importance in glass manufacture, from melting and homogenization of the batch to the application of forming and cooling regimes. Viscosity is a type of internal friction in fluids and varies with temperature and glass composition. In glass production, the important critical viscosity points affecting and determining the behavior of molten glass in the furnace and during forming are as follows:

[0044] • Melting region: The temperature region where the batch is completely melted. In this region, viscosity is 10-102Poise. Its technical importance is that, to produce a high-quality, clean glass, the molten glass must be raised to this temperature level (generally -1450 °C) and held in the furnace for a certain period, which entails energy consumption.

[0045] • Gob (dropping) temperature (T3): The temperature at which viscosity is 103Poise. Technically, this is the temperature at which the glass gob is taken from the furnace for forming (generally -1100 °C).

[0046] • Softening temperature (Ts): The temperature at which viscosity is 107-65Poise. In practice, glass can only be shaped at temperatures above this temperature (generally -750 °C).

[0047] • Annealing temperature (TA): The temperature at which viscosity is 1013Poise, at which internal stresses in the glass are practically eliminated within 15 minutes (generally -550 °C).

[0048] • Strain temperature (Tst): The temperature at which viscosity is 1014-5Poise, at which internal stresses in the glass are eliminated in approximately 4 hours (generally -525 °C).

[0049] Viscosity changes directly with glass composition and is determined by different measurement methods in different temperature ranges. While high-temperature viscometers are used for measuring the viscosity of molten glass in the liquid phase at high temperatures (e.g., melting and gob temperatures), for lower temperatures representing the solidified form of glass (e.g., softening, annealing and strain temperatures), measurements are made via fiber elongation according to the methods described in ASTM C965, ASTM C338 and ASTM C336. In addition, viscosity can be calculated based on glass composition. Figure 2 provides a comparative graph showing how the viscosities of a conventional soda-lime silicate glass and the glass of the present invention vary with temperature. Viscosity is one of the most critical properties for glass manufacture; to ensure stable production, the viscosity curve and melting temperature (log q = 2 Poise) were found to be similar for both glasses.

[0050] A quality glass production starts with obtaining a homogeneous glass melt and is completed by performing the fining process by holding at high temperature for long periods. Therefore, to obtain a defect-free melt, it is necessary to reach sufficient temperature and hold for long periods, which directly affects energy consumption. With the present invention, homogenization and fining processes of the glass composition can occur faster and more effectively compared with conventional soda-lime silicate glasses. Figure 3 shows images from experiments of fining examinations of a conventional soda-lime silicate glass and the glass of the invention. After melting the two glasses at the same temperature for different times, the gaseous inclusions remaining in the glass and other quality defects are compared. It was determined that the glass of the invention showed a cleaner appearance for the same times. In this way, more efficient and more energy-effective production will be achievable.

[0051] As noted, glass composition is an important parameter affecting viscosity; changes in composition also alter the melting temperature, i.e., the energy required to obtain a homogeneous melt. In this sense, components such as SiO2and AI2O3increase viscosity, shifting the melting point to higher temperatures. While the effect of B2O3on viscosity depends on the other oxides present in the glass system, when B2O3enters the silica glass structure, it reduces viscosity from the softening point to the melting region. Components such as Na2O and K2O reduce viscosity at all points; components such as CaO and MgO reduce high-temperature viscosity while increasing low-temperature viscosity. In a classic soda-lime silicate glass batch, the components that reduce the melting temperature, primarily Na2O and also CaO and MgO, are supplied by carbonate raw materials; reducing their proportions and the resulting change in composition affects the melting temperature. In the present invention, the melting temperature of the low-CO2-emission glass composition is at a level similar to that of classic soda-lime glass and is compatible with existing production technologies.

[0052] Forming. The formability of the glass or how the forming process will occur is largely influenced by glass viscosity. The forming range is the temperature range in which glass is shaped — from the temperature at which the gob is cut (q = 103Poise) to the softening point (q = 107-65Poise), which is the transition from a liquid to a rigid form and where forming ends. In this sense, the working range (WR) is a parameter used to describe the forming region. A low WR value indicates a “short” glass requiring rapid forming; a high WR value indicates a “longer” glass allowing slower forming. Ideal WR values vary with product shape and size, and can be modified by changing composition. In hollow-glass production technologies (bottles, jars, tumblers, goblets, etc.), the equipment known in the art — IS, Rotary, Spinning, Press and Press / Blow machines — operate under certain cooling regimes; therefore, the working range of the glass to be produced must be compatible with these technologies. Similarly, flat glass production lines operate under a particular thermal regime with float technology; therefore, the viscosity profile of the glass must be compatible with the production process. It is therefore critical that the viscosity of the glass composition of the invention is close to that of classic soda-lime silicate glasses.

[0053] Crystallization resistance. Glass can be obtained by cooling a melt produced at high temperature sufficiently slowly for shaping but sufficiently fast to avoid crystallization. If the cooling rate is insufficient, i.e., if the temperature of the glass slowly drops below the crystallization (liquidus) temperature Tliq, it tends to lose its amorphous structure and transition to a crystalline phase. If the crystallization temperature is higher than the gob (dropping) temperature, crystallization will begin during gobbing, resulting in defects in the product. Therefore, it is desirable that the crystallization temperature be lower than the gob temperature and that the temperature difference (AT = T3— Tliq) be high to provide comfort in forming. In this sense, the crystallization temperature is an important parameter in production and directly depends on glass composition. While the crystallization temperature can be measured with a gradient furnace, it can also be calculated with high consistency based on composition. For the disclosed invention, the crystallization temperature determined by calculation is stated. It has also been verified that experimental measurements give similar results.

[0054] Chemical durability. The corrosion resistance of the glass material is decisive for the quality of the final product. For example, by their nature, glass packaging products are in contact with various beverages and foods, and flat glass products (e.g., windows) are in contact with the humid atmosphere in which they are located. It is undesirable that corrosion products formed during use and storage of the glass material should leach into the medium in contact with the glass. Therefore, high corrosion resistance of the final product is an important parameter for product quality. While there are various tests to determine the chemical durability of glass products, the measurement techniques specified in ISO 719 and ISO 4802-1 / 2010 standards were taken as the basis for the disclosed invention. Chemical durability can also be calculated based on glass composition. As shown in Figure 5, measurements were also made on prototype specimens of the invention.

[0055] Table 1 . Limiting values for determining ISO 719 hydrolytic durability class Among the hydrolytic durability classes given in Table 1 , class 1 represents the highest durability and class 5 the lowest durability.

[0056] Table 2. Limiting values for determining ISO 4802-1 / 2010 hydrolytic durability class

[0057] Among the hydrolytic durability classes given in Table 2, HOT 1 represents the highest durability and class HOT D the lowest.

[0058] Mechanical strength. Mechanical strength of the glass material is decisive for final product quality. In glass manufacture, mechanical properties play a critical role in minimizing breakage risk to ensure safe storage / transport and use of products. Increasing mechanical strength also enables production of thinner-walled, lighter products. Although various tests can be applied to determine mechanical strength of glass products, comparison of Young’s modulus (E, GPa) is taken as the basis for the disclosed invention. Young’s modulus can also be calculated based on glass composition. Physical properties. Density, a fundamental physical property, is carefully monitored during development using the Archimedes method. The room-temperature densities of conventional glasses are -2.50 g / cm3; the density of the glass of the invention is kept at similar levels. Another parameter among the physical properties of glass products is the optical property refractive index, measured with an Abbe refractometer. While refractive indices of conventional glasses are < 1 .52, the glass of the invention is kept at similar levels. The coefficient of thermal expansion determines the extent of dimensional change of glass with temperature variations and directly affects structural integrity. Products with low coefficients of thermal expansion are more resistant to temperature changes. Therefore, a low coefficient of thermal expansion is important for both safety and long service life. While conventional glasses have coefficients of thermal expansion of 80-100 x 10"7°C, the glass composition of the invention is maintained at a similar order of expansion.

[0059] The glass composition of the invention comprises, in weight percent, 55-70 SiO2, 5-15AI2O3, 5-15 MgO, 5-18 Na2O, 0-8 CaO, 0-4 B2O3and other minor additions. This special composition renders the glass environmentally friendly while optimizing mechanical strength, chemical resistance and optical properties. Thus, it makes possible the production of high-performance glasses offering both environmental and functional features. SiO2, as the principal component, provides high strength and durability. AI2O3increases mechanical and chemical durability, while MgO and CaO improve melting and forming behavior. Na2O lowers the melting point, facilitating production and saving energy. B2O3increases thermal shock resistance and regulates viscosity. Fe2O3and Cr2O3control color properties. SO3plays an active role in the fining process to produce a quality product. This composition is an environmental solution for glassware and industrial use, increasing efficiency in production processes and maximizing the performance and durability of the final product. This new composition overcomes limitations of existing technologies and enables the production of more environmentally friendly glass products with high chemical and mechanical performance and long service life.

[0060] Conventional soda-lime silicate glass composition and example glass compositions of the invention are given comparatively with process- and performance-critical material properties in Tables 3, 4 and 5.

[0061] Table 3. Conventional soda-lime silicate glass composition and example glass compositions of the invention for glassware, with properties (comparison)

[0062] Chemical composition (wt.%)

[0063] For the viscosity values given in Table 3: log q = 2 (Poise) indicates the temperature at which the glass viscosity is 100 Poise and melting is performed; log q = 3 (Poise) indicates the temperature at which the glass viscosity is 1000 Poise and forming begins; log q = 7.65 (Poise) indicates the temperature at which viscosity is approximately 107-65Poise and forming ends; log q = 13 (Poise) indicates the temperature at which viscosity is approximately 1013Poise and annealing is performed.

[0064] The tables above show the percentage weight ratio values of the materials used in the glass composition. The traditional soda-lime-silicate glass composition shown in Table 3 contains by weight ratio 71.32% SiO2, 1.70% AI2O3, <0.1 % Fe2O3, <0.1 % TiO2, 10% CaO, 3.15% MgO, 13.60% Na2O, 0.03% K2O, and 0.23% SO3. The temperature of the reference glass with the traditional soda-lime-silicate composition at a viscosity value of logq=2 was determined to be 1441 °C, at logq=3 (Poise) viscosity it was 1192°C, at logq=7.65 (Poise) viscosity it was 728°C, and at logq=13 (Poise) viscosity it was 551 °C. The crystallization temperature was found to be 1047°C and the difference between the gob temperature and the crystallization temperature was 142°C. A traditional soda-lime-silicate glass composition has a density of 2.520 g / cm3. The thermal expansion coefficient of the soda-lime-silicate reference glass is 92.34 and its Young's modulus value is approximately 70 GPa. The hydrolytic resistance class of the reference glass according to ISO 719 was determined as HGB 4 and its chemical resistance according to ISO 4802 was determined as HOT 3. During the melting of traditional soda-lime- silicate glass, an emission of the order of -210 kg CO2 / ton of glass occurs as a result of decomposition reactions.

[0065] Example 1 shown in Table 3 contains 62.30% SiO2, 8.50% AI2O3, <0.1 % Fe2O3, 0.1 % TiO2, 5.50% CaO, 9.50% MgO, 12.00% Na2O, 0.1 % K2O, 0.20% SO3, and 2.00% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1452°C, at logq=3 (Poise) viscosity it was 1230°C, at logq=7.65 (Poise) viscosity it was 767°C, and at logq=13 (Poise) viscosity it was 565°C. The crystallization temperature was found to be 1107°C and the difference between the gob temperature and the crystallization temperature was 123°C. The glass with low CO2 emission and improved material properties having the Example 1 composition has a density of 2.514 g / cm3. The thermal expansion coefficient of the glass of the invention is 79.80 and its Young's modulus value is 79.90 GPa. The hydrolytic resistance class of the Example 1 glass according to ISO 719 was determined as HGB 3 and its hydrolytic resistance class according to ISO 4802 was determined as HOT B. During the melting of the Example 1 glass, an emission of the order of -65 kg CO2 / ton of glass occurs, providing a 69% reduction compared to the prior art.

[0066] Example 2 shown in Table 3 contains 60.90% SiO2, 10.50% AI2O3, <0.1 % Fe2O3, 0.1 % TiO2, 3.00% CaO, 10.00% MgO, 15.50% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1474°C, at logq=3 (Poise) viscosity it was 1241 °C, at logq=7.65 (Poise) viscosity it was 757°C, and at logq=13 (Poise) viscosity it was 546°C. The crystallization temperature was found to be 1073°C and the difference between the gob temperature and the crystallization temperature was 168°C. The glass with low CO2 emission and improved material properties having the Example 2 composition has a density of 2.510 g / cm3. The thermal expansion coefficient of the glass of the invention is 93.5 and its Young's modulus value is 78 GPa. The hydrolytic resistance class of the Example 2 glass according to ISO 719 was determined as HGB 3 and its hydrolytic resistance class according to ISO 4802 was determined as HOT B. During the melting of the Example 2 glass, an emission of the order of -100 kg CO2 / ton of glass occurs, providing a 52% reduction compared to the prior art.

[0067] Example 3 shown in Table 3 contains 60.42% SiO2, 9.40% AI2O3, <0.1 % Fe2O3, 0.1 % TiO2, 3.20% CaO, 9.40% MgO, 16.40% Na2O, 0.4% K2O, and <0.20% SO3. The temperature of the glass of the invention at a viscosity value of logq =2 was determined to be 1450°C, at logq =3 (Poise) viscosity it was 1215°C, at logq=7.65 (Poise) viscosity it was 739°C, and at logq=13 (Poise) viscosity it was 536°C. The crystallization temperature was found to be 1043°C and the difference between the gob temperature and the crystallization temperature was 172°C. The glass with low CO2 emission and improved material properties having the Example 3 composition has a density of 2.518 g / cm3. The thermal expansion coefficient of the glass of the invention is 98.1 and its Young's modulus value is 77.7 GPa. The hydrolytic resistance class of the Example 3 glass according to ISO 719 was determined as HGB 3 and its hydrolytic resistance class according to ISO 4802 was determined as HOT B. During the melting of the Example 3 glass, an emission of the order of ~115 kg CO2 / ton of glass occurs, providing a 45% reduction compared to the prior art.

[0068] Example 4 shown in Table 3 contains 59.80% SiO2, 10.00% AI2O3, <0.1 % Fe2O3, 0.1 % TiO2, 4.00% CaO, 10.00% MgO, 12.00% Na2O, 0.1 % K2O, 0.20% SO3, and 4.00% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1433°C, at logq=3 (Poise) viscosity it was 1224°C, at logq=7.65 (Poise) viscosity it was 772°C, and at logq=13 (Poise) viscosity it was 567°C. The crystallization temperature was found to be 1087°C and the difference between the gob temperature and the crystallization temperature was 137°C. The glass with low CO2 emission and improved material properties having the Example 4 composition has a density of 2.504 g / cm3. The thermal expansion coefficient of the glass of the invention is 77.96 and its Young's modulus value is 78.9 GPa. The hydrolytic resistance class of the Example 4 glass according to ISO 719 was determined as HGB 3 and its hydrolytic resistance class according to ISO 4802 was determined as HOT B. During the melting of the Example 4 glass, an emission of the order of ~50 kg CO2 / ton of glass occurs, providing a 76% reduction compared to the prior art.

[0069] Table 4. Conventional soda-lime silicate glass and further example glass compositions of the invention (comparison, continued)

[0070] Example 5 shown in Table 4 contains 51.85% SiO2, 15.00% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 0.00% CaO, 15.00% MgO, 18.00% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1409°C, at logq=3 (Poise) viscosity it was 1227°C, at logq=7.65 (Poise) viscosity it was 780°C, and at logq=13 (Poise) viscosity it was 548°C. The glass with low CO2 emission and improved material properties having the Example 5 composition has a density of 2.512 g / cm3. The thermal expansion coefficient of the glass of the invention is 98.77 and its Young's modulus value is 81.7 GPa. The hydrolytic resistance class of the Example 5 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 5 glass, an emission of the order of -120 kg CO2 / ton of glass occurs, providing a 42% reduction compared to the known state of the art.

[0071] Example 6 shown in Table 4 contains 62.25% SiO2, 9.30% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 2.80% CaO, 9.60% MgO, 16.00% Na2O, 0.1 % K2O, 0.15% SO3, and 1.30% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1434°C, at logq=3 (Poise) viscosity it was 1210°C, at logq=7.65 (Poise) viscosity it was 745°C, and at logq=13 (Poise) viscosity it was 548°C. The crystallization temperature was found to be 1024°C and the difference between the gob temperature and the crystallization temperature was 186°C. The glass with low CO2 emission and improved material properties having the Example 6 composition has a density of 2.507 g / cm3. The thermal expansion coefficient of the glass of the invention is 90.89 and its Young's modulus value is 77.9 GPa. The hydrolytic resistance class of the Example 6 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 6 glass, an emission of the order of -107 kg CO2 / ton of glass occurs, providing a 49% reduction compared to the known state of the art.

[0072] Example 7 shown in Table 4 contains 56.75% SiO2, 4.90% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 7.00% CaO, 14.20% MgO, 17.05% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1315°C, at logq=3 (Poise) viscosity it was 1101 °C, at logq=7.65 (Poise) viscosity it was 694°C, and at logq=13 (Poise) viscosity it was 529°C. The glass with low CO2 emission and improved material properties having the Example 7 composition has a density of 2.577 g / cm3. The thermal expansion coefficient of the glass of the invention is 103.37 and its Young's modulus value is 78.0 GPa. The hydrolytic resistance class of the Example 7 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 7 glass, an emission of the order of -120 kg CO2 / ton of glass occurs, providing a 42% reduction compared to the known state of the art.

[0073] Example 8 shown in Table 4 contains 63.95% SiO2, 5.50% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 4.90% CaO, 10.20% MgO, 15.30% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1430°C, at logq=3 (Poise) viscosity it was 1196°C, at logq=7.65 (Poise) viscosity it was 732°C, and at logq=13 (Poise) viscosity it was 537°C. The crystallization temperature was found to be 1116°C and the difference between the gob temperature and the crystallization temperature was 81 °C. The glass with low CO2 emission and improved material properties having the Example 8 composition has a density of 2.521 g / cm3. The thermal expansion coefficient of the glass of the invention is 95.39 and its Young's modulus value is 76.9 GPa. The hydrolytic resistance class of the Example 8 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 8 glass, an emission of the order of -120 kg CO2 / ton of glass occurs, providing a 42% reduction compared to the known state of the art.

[0074] Example 9 shown in Table 4 contains 60.75% SiO2, 7.50% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 4.10% CaO, 13.30% MgO, 14.20% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1435°C, at logq=3 (Poise) viscosity it was 1218°C, at logq=7.65 (Poise) viscosity it was 755°C, and at logq=13 (Poise) viscosity it was 548°C. The glass with low CO2 emission and improved material properties having the Example 9 composition has a density of 2.528 g / cm3. The thermal expansion coefficient of the glass of the invention is 90.77 and its Young's modulus value is 79.2 GPa. The hydrolytic resistance class of the Example 9 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 9 glass, an emission of the order of -97 kg CO2 / ton of glass occurs, providing a 53% reduction compared to the known state of the art.

[0075] Table 5. Comparison of traditional soda-lime-silicate glass composition for glassware products and example glass compositions of the invention and their properties (continued)

[0076]

[0077] Example 10 shown in Table 5 contains 60.65% SiO2, 5.20% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 7.90% CaO, 13.90% MgO, 12.20% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1398°C, at logq=3 (Poise) viscosity it was 1184°C, at logq=7.65 (Poise) viscosity it was 745°C, and at logq=13 (Poise) viscosity it was 556°C. The glass with low CO2 emission and improved material properties having the Example 10 composition has a density of 2.558 g / cm3. The thermal expansion coefficient of the glass of the invention is 88.00 and its Young's modulus value is 79.3 GPa. The hydrolytic resistance class of the Example 10 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 10 glass, an emission of the order of -122 kg CO2 / ton of glass occurs, providing a 41 % reduction compared to the known state of the art.

[0078] Example 11 shown in Table 5 contains 63.85% SiO2, 7.00% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 0.50% CaO, 13.50% MgO, 15.00% Na2O, 0.1 % K2O, 0.15% SO3, and 2.00% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1433°C, at logq=3 (Poise) viscosity it was 1232°C, at logq=7.65 (Poise) viscosity it was 767°C, and at logq=13 (Poise) viscosity it was 550°C. The crystallization temperature was found to be 1159°C and the difference between the gob temperature and the crystallization temperature was 73°C. The glass with low CO2 emission and improved material properties having the Example 11 composition has a density of 2.498 g / cm3. The thermal expansion coefficient of the glass of the invention is 85.70 and its Young's modulus value is 78.4 GPa. The hydrolytic resistance class of the Example 11 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 11 glass, an emission of the order of ~73 kg CO2 / ton of glass occurs, providing a 65% reduction compared to the known state of the art.

[0079] Example 12 shown in Table 5 contains 61.45% SiO2, 8.30% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 8.20% CaO, 8.50% MgO, 13.40% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1433°C, at logq=3 (Poise) viscosity it was 1198°C, at logq=7.65 (Poise) viscosity it was 745°C, and at logq=13 (Poise) viscosity it was 562°C. The crystallization temperature was found to be 1128°C and the difference between the gob temperature and the crystallization temperature was 69°C. The glass with low CO2 emission and improved material properties having the Example 12 composition has a density of 2.540 g / cm3. The thermal expansion coefficient of the glass of the invention is 91.41 and its Young's modulus value is 78.4 GPa. The hydrolytic resistance class of the Example 12 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 12 glass, an emission of the order of -120 kg CO2 / ton of glass occurs, providing a 42% reduction compared to the known state of the art.

[0080] Example 13 shown in Table 5 contains 61.25% SiO2, 10.40% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 2.80% CaO, 10.40% MgO, 15.00% Na2O, 0.1 % K2O, and 0.15% SO3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1432°C, at logq=3 (Poise) viscosity it was 1217°C, at logq=7.65 (Poise) viscosity it was 757°C, and at logq=13 (Poise) viscosity it was 558°C. The crystallization temperature was found to be 1081 °C and the difference between the gob temperature and the crystallization temperature was 136°C. The glass with low CO2 emission and improved material properties having the Example 13 composition has a density of 2.506 g / cm3. The thermal expansion coefficient of the glass of the invention is 87.20 and its Young's modulus value is 79.0 GPa. The hydrolytic resistance class of the Example 13 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 13 glass, an emission of the order of -83 kg CO2 / ton of glass occurs, providing a 60% reduction compared to the known state of the art.

[0081] Example 14 shown in Table 5 contains 57.35% SiO2, 9.50% AI2O3, 0.1 % Fe2O3, 0.1 % TiO2, 1.00% CaO, 15.00% MgO, 17.00% Na2O, 0.1 % K2O, 0.15% SO3, and 1.90% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1414°C, at logq=3 (Poise) viscosity it was 1215°C, at logq=7.65 (Poise) viscosity it was 764°C, and at logq= 13 (Poise) viscosity it was 538°C. The glass with low CO2 emission and improved material properties having the Example 14 composition has a density of 2.520 g / cm3. The thermal expansion coefficient of the glass of the invention is 97.25 and its Young's modulus value is 76.6 GPa. The hydrolytic resistance class of the Example 14 glass according to ISO 719 was determined as HGB 3. During the melting of the Example 14 glass, an emission of the order of ~96 kg CO2 / ton of glass occurs, providing a 54% reduction compared to the known state of the art.

[0082] Table 6. Comparison of traditional soda-lime-silicate glass composition for hollow products and example glass compositions of the invention and their properties

[0083] For the viscosity values given in Table 6; the expression logq=2 (Poise) indicates the temperature at which the glass viscosity is 100 Poise, the expression logq=3 (Poise) indicates the temperature at which the glass viscosity is 1000 Poise. The expression logq=7.65 (Poise) indicates the temperature at which the glass viscosity is approximately 107.65Poise.

[0084] The tables above show the percentage weight ratio values of the materials used in the hollow glass composition. The traditional hollow glass composition, soda-lime-silicate, shown in Table 6 contains by weight ratio 71.32% SiO2, 1.70% AI2O3, <0.1 % Fe2O3, <0.1 % TiO2, 10% CaO,

[0085] 3.15% MgO, 13.60% Na2O, 0.03% K2O, and 0.23% SO3. The temperature of the reference glass with the traditional soda-lime-silicate composition at a viscosity value of logq=2 was determined to be 1441 °C, at logq=3 (Poise) viscosity it was 1192°C, at logq=7.65 (Poise) viscosity it was 728°C, and at logq=13 (Poise) viscosity it was 551 °C. The crystallization temperature was found to be 1047°C and the difference between the gob temperature and the crystallization temperature was 142°C. A traditional hollow glass composition, soda-lime- silicate, has a density of 2.5134 g / cm3and a refractive index of 1.5184. The thermal expansion coefficient of the soda-lime-silicate reference glass is 92.34 and its Young's modulus value is 68 GPa. The hydrolytic resistance class of the reference glass according to ISO 719 was determined as 4. During the melting of traditional soda-lime-silicate glass, an emission of the order of -200 kg CO2 / ton of glass occurs as a result of decomposition reactions.

[0086] Example 15 shown in Table 6 contains 62% SiO2, 8.5% AI2O3, <0.1 % Fe2O3, 0.05% TiO2, 5.5% CaO, 9.5% MgO, 12% Na2O, 0.1 % K2O, 0.23% SO3, and 2% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1443°C, at logq=3 (Poise) viscosity it was 1222°C, at logq=7.65 (Poise) viscosity it was 763°C, and at logq = 13 (Poise) viscosity it was 560°C. The crystallization temperature was found to be 1137°C and the difference between the gob temperature and the crystallization temperature was 85°C. The glass with low CO2 emission and improved material properties having the Example 15 composition has a density of 2.4825 g / cm3and a refractive index of 1.5179. The thermal expansion coefficient of the glass of the invention is 81 .30 and its Young's modulus value is 75 GPa. The hydrolytic resistance class of the Example 15 glass according to ISO 719 was determined as 3.

[0087] Example 16 shown in Table 6 contains 64% SiO2, 8.5% AI2O3, 0.255% Fe2O3, 0.05% TiO2, 5.5% CaO, 9.5% MgO, 12% Na2O, 0.3% K2O, 0.24% Cr2O3, 0.05% SO3, and 0% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1498°C, at logq=3 (Poise) viscosity it was 1258°C, at logq=7.65 (Poise) viscosity it was 770°C, and at logq=13 (Poise) viscosity it was 561 °C. The crystallization temperature was found to be 1137°C and the difference between the gob temperature and the crystallization temperature was 121 °C. The glass with low CO2 (130 kgCO2 / ton glass) emission and improved material properties having the Example 16 composition has a density of 2.4946 g / cm3and a refractive index of 1.5167. The thermal expansion coefficient of the glass of the invention is 85.60 and its Young's modulus value is 74 GPa. The hydrolytic resistance class of the Example 16 glass according to ISO 719 was determined as 3. Figure 4 shows the calculated Young's modulus values for sample glasses of traditional soda-lime-silicate and the present invention. Compared to the Young's modulus values of traditional soda-lime-silicate glass (SLS), it was determined that the glass composition of the invention has higher values.

[0088] Example 17 shown in Table 6 contains 59% SiO2, 8.5% AI2O3, 0.255% Fe2O3, 0.05% TiO2, 5.5% CaO, 9.5% MgO, 12% Na2O, 0.3% K2O, 0.24% Cr2O3, 0.05% SO3, and 5% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1374°C, at log q=3 (Poise) viscosity it was 1172°C, at logq=7.65 (Poise) viscosity it was 759°C, and at logq=13 (Poise) viscosity it was 564°C. The crystallization temperature was found to be 1137°C and the difference between the gob temperature and the crystallization temperature was 35°C. The glass with low CO2 (130 kgCO2 / ton glass) emission and improved material properties having the Example 17 composition has a density of 2.4514 g / cm3and a refractive index of 1.5199. The thermal expansion coefficient of the glass of the invention is 80.83 and its Young's modulus value is 75 GPa. The hydrolytic resistance class of the Example 17 glass according to ISO 719 was determined as 3. Figure 5 shows images of trial samples produced as prototypes targeting the glass composition of the invention. It was seen that the present composition is suitable and preferable for the production of glassware. Figures 6.A and 6.B show the hydrolytic resistance values of traditional soda-lime-silicate glass and the glass of the present invention, determined according to ISO 719 and ISO 4802 methods, respectively. Compared to the hydrolytic values of traditional soda-lime-silicate glass (SLS), it was determined that the glass composition of the invention has higher values.

[0089] Example 18 shown in Table 6 contains 62% SiO2, 8.5% AI2O3, 0.255% Fe2O3, 0.05% TiO2, 5.5% CaO, 9.5% MgO, 12% Na2O, 0.3% K2O, 0.24% Cr2O3, 0.05% SO3, and 2% B2O3. The temperature of the glass of the invention at a viscosity value of logq=2 was determined to be 1445°C, at log q=3 (Poise) viscosity it was 1170°C, at logq=7.65 (Poise) viscosity it was 764°C, and at logq=13 (Poise) viscosity it was 563°C. The crystallization temperature was found to be 1137°C and the difference between the gob temperature and the crystallization temperature was 87°C. The glass with low CO2 (130 kgCO2 / ton glass) emission and improved material properties having the Example 18 composition has a density of 2.4836 g / cm3and a refractive index of 1.5182. The thermal expansion coefficient of the glass of the invention is 81.30 and its Young's modulus value is 75 GPa. The hydrolytic resistance class of the Example 18 glass according to ISO 719 was determined as 3. The example raw material mixtures prepared for the production of the low CO2 emission sample glass compositions given in Tables 3, 4, 5, and 6 are, by weight percentage, 0-20% sand, 20-60% feldspar, 0-15% limestone, 0-15% dolomite, 20-45% talc, 10-20% soda ash, 0-13% colemanite, and 0-1 % sodium sulfate.

Claims

CLAIMS1 . A glass composition for a glass article, in particular a hollow glass article, characterized by comprising, in weight percent:55-70 SiO2;5-15AI2O3;5-15 MgO;5-18 Na2O, preferably 6-16 Na2O, more preferably 6-15 Na2O;0-8 CaO, preferably 2-8 CaO, more preferably 3-8 CaO; and 0—4 B2O3.

2. The glass composition according to claim 1 , wherein the SiO2content is 57-68 wt.%, preferably 58-65 wt.%.

3. The glass composition according to any of the preceding claims, wherein the AI2O3content is 6-13 wt.%, preferably 6-10 wt.%.

4. The glass composition according to any of the preceding claims, wherein the MgO content is 6-13 wt.%, preferably 8-12 wt.%.

5. The composition according to any of the preceding claims, wherein the Na2O content is 8-17 wt.%, preferably 8-14 wt.%.

6. The glass composition according to any of the preceding claims, wherein the CaO content is 1-6 wt.%, preferably 4-7 wt.%.

7. The glass composition according to any of the preceding claims, wherein the B2O3content is 0-3 wt.%.

8. The glass composition according to any of the preceding claims, wherein the Fe2O3content is 0-1 wt.%.

9. The glass composition according to any of the preceding claims, wherein the Cr2O3content is 0-1 wt.%.

10. The glass composition according to any of the preceding claims, wherein the K2O content is 0-1 wt.%.

11. The glass composition according to any of the preceding claims, wherein the SO3content is 0.01-0.5 wt.%.

12. The glass composition according to any of the preceding claims, wherein the TiO2content is 0-1 wt.%, in particular 0-0.5 wt.%.

13. A glass obtainable with a glass composition according to any of the preceding claims.

14. The glass according to claim 13, wherein the difference between the gob (dropping) temperature and the crystallization (liquidus) temperature (T3— Tliq) is at least 35 °C.

15. The glass according to any of claims 13-14, wherein the emissions resulting from decomposition reactions of the raw materials used to obtain the composition are approximately 50-120 kg CO2 / tonne glass.

16. The glass according to any of claims 13-15, wherein chemical durability thereof remains within class 3 according to the method specified in ISO 719 and preferably within class HCT-B according to the method specified in ISO 4802-1 / 2010.

17. The glass according to any of claims 13-16, wherein the Young’s modulus of the glass obtained is at least 74 GPa.

18. A glass article obtained from a glass according to any of claims 13-17, wherein the glass article is selected from the group consisting of flat, plate, hollow, corrugated, flat glass, glass packaging, window, automotive glass, architectural glass, plate, sheet, bottle, jar, household ware, tumbler, goblet, container and vase.

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