Display glass containing k2o

Abstract

A glass composition includes from about 60 mol% to about 80 mol% SiO2, from 0 mol% to about 11 mol% Al2O3, from about 4.0 mol% to about 12 mol% B2O3, from about 0.5 mol% to about 20 mol% K2O, from 0 mol% to about 18.5 mol% MgO, and from 0 mol% to about 1 mol% SnO2. The glass composition has a CTE, which can be adjusted based on the composition, and the glass composition can be used in display applications.

Description

[0001] Priority claims and cross-references

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 009102, filed April 13, 2020, which is based on and whose entire contents are incorporated herein by reference. This application is a divisional application of U.S. Patent Application No. 202180031843.6, filed March 29, 2021, entitled "Display Glass Containing K2O". Technical Field

[0003] In general, this disclosure relates to glass compositions. More specifically, the disclosed subject matter relates to glass compositions containing alkali metals and suitable for display applications. Background Technology

[0004] Flat or curved substrates made of optically transparent materials such as glass are used in flat panel displays, photovoltaic devices, and other suitable applications. In addition to the requirement for optical transparency, glass compositions also need to meet different challenges depending on the manufacturing process and application.

[0005] For example, the production of liquid crystal displays (LCDs) for active-array liquid crystal displays (AMLCDs) is complex, and the properties of the substrate glass are crucial. The physical dimensions of the glass substrates used in the production of AMLCDs need to be strictly controlled. Down-drawing sheet stretching processes (especially melting processes) can produce glass sheets suitable for use as substrates without expensive post-forming operations such as grinding and polishing. However, melting processes impose rather strict limitations on glass properties, requiring relatively high liquid phase viscosity.

[0006] In the field of liquid crystal displays (LCDs), thin-film transistors (TFTs) can be based on polycrystalline silicon (p-Si) or amorphous silicon (a-Si). Amorphous silicon offers advantages such as lower processing temperatures. Sometimes, however, polycrystalline silicon is preferred because it can transport electrons more efficiently. Polycrystalline silicon-based transistors are characterized by higher mobility than amorphous silicon-based transistors. This allows for the fabrication of smaller and faster transistors, ultimately resulting in brighter and faster displays. One issue with p-Si transistors is that their fabrication requires significantly higher process temperatures compared to a-Si transistors. These temperatures range from 450°C to 600°C, compared to the 350°C peak temperature used to manufacture a-Si transistors.

[0007] To meet processing and performance requirements, glass compositions used in display applications need to possess good thermal and mechanical properties as well as dimensional stability. Furthermore, the diffusion of metal ions into thin-film transistors can damage them. Such diffusion needs to be minimized or eliminated. Summary of the Invention

[0008] This disclosure provides glass compositions containing alkali metals (such as potassium), methods for manufacturing the same, and methods for using the same. This disclosure also provides glass substrates comprising such glass compositions, and display devices comprising such glass compositions or glass substrates, wherein the glass substrate has such glass compositions.

[0009] According to some embodiments, the glass composition is essentially composed of the following components:

[0010] Approximately 60 mol% to approximately 80 mol% of SiO2;

[0011] 0 mol% to approximately 11 mol% of Al2O3;

[0012] Approximately 4.0 mol% to approximately 12 mol% of B2O3;

[0013] Approximately 0.5 mol% to approximately 20 mol% of K₂O;

[0014] 0 mol% to about 18.5 mol% MgO; and

[0015] SnO2 from 0 mol% to approximately 1 mol%.

[0016] In the composition, the components are selected from the above six oxides. In some embodiments, K₂O is the only added alkali metal oxide, and other alkali metal oxides such as Li₂O and Na₂O are not included or substantially absent. MgO is the only added alkaline earth metal oxide, and CaO, SrO, or BaO are not included or substantially absent.

[0017] The glass composition contains SiO2 in any suitable range. Suitable examples include, but are not limited to, about 60 mol% to about 75 mol%, about 65 mol% to about 80 mol%, or about 65 mol% to about 75 mol%. In some embodiments, the SiO2 content is equal to or less than 75 mol%, for example, in the range of about 60 mol% to about 75 mol%.

[0018] In some embodiments, the Al2O3 content is equal to or less than 11 mol%. Examples of suitable ranges for Al2O3 include, but are not limited to: about 0.1 mol% to about 10.5 mol%, about 0.1 mol% to about 2 mol%, about 2 mol% to about 10.5 mol%, about 4 mol% to about 10.5 mol%, or any other suitable range.

[0019] In some embodiments, the alkali metal oxide is K₂O in any suitable range. Examples of suitable ranges for K₂O include, but are not limited to: about 0.5 mol% to about 15 mol%, about 1 mol% to about 15 mol%, about 3.5 mol% to about 15 mol%, about 3 mol% to about 15 mol%, or about 3 mol% to about 10 mol%.

[0020] Examples of suitable ranges for MgO include, but are not limited to: 0 mol% to about 15 mol%, 0 mol% to about 10 mol%, 0 mol% to about 6 mol%, 0.1 mol% to about 15 mol%, about 0.1 mol% to about 10 mol%, 0.1 mol% to about 0.6 mol%, or about 10 mol% to about 18.5 mol%. In some embodiments, the MgO content is equal to or less than 6 mol%, for example, in the range of 0 mol% to about 2 mol%. In some embodiments, the MgO content is equal to or greater than 10 mol%, for example, in the range of about 10 mol% to about 18.5 mol%, or about 16 mol% to about 18.5 mol%.

[0021] Examples of suitable ranges for B2O3 include, but are not limited to: about 4.9 mol% to about 11.5 mol%, about 6 mol% to about 11 mol%, or about 8 mol% to about 11 mol%.

[0022] The composition may contain any other suitable ingredient, such as SnO2. Examples of suitable ranges for SnO2 include, but are not limited to, from about 0.01 mol% to about 0.5 mol% or from about 0.05 mol% to about 0.15 mol%.

[0023] This disclosure provides for any suitable composition having different combinations of the ingredients and content ranges described herein.

[0024] In some embodiments, the molar ratio of K2O / Al2O3 is in the range of about 0.4 to about 360, for example, from about 0.4 to about 2, from about 1 to about 10, from about 1 to about 100, from about 100 to about 200, or from about 200 to about 360. In some embodiments, the K2O / Al2O3 ratio is in the range of about 1 to about 10, for example, from about 0.4 to about 2.

[0025] In some embodiments, the molar ratio of MgO / Al2O3 is in the range of 0 to about 10, for example, from 0 to about 4, or from 0 to about 1. The molar ratio of SiO2 / B2O3(k) may be in the range of about 6 to about 15.

[0026] In some embodiments, the R' value defined as ([K2O]-[Al2O3]) / [B2O3] is in the range of about -0.7 to about 0.7, and the R” value defined as ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3] is in the range of about -0.3 to about 1.3. [K2O], [MgO], [Al2O3] and [B2O3] represent the molar contents of K2O, MgO, Al2O3 and B2O3, respectively.

[0027] In some embodiments, at temperatures ranging from 20°C to 300°C, the coefficient of thermal expansion (CTE) of the glass composition ranges from approximately 40 × 10⁻⁶. -7 / ℃ to approximately 85×10 -7 The CTE can be adjusted according to the composition for different applications. For example, the CTE is in the following range: from approximately 40 × 10⁻⁶ °C. -7 / ℃ to approximately 80×10 -7 / ℃ or from approximately 40×10 -7 / ℃ to approximately 70×10 -7 / ℃, from approximately 40×10 -7 / ℃ to approximately 60×10 -7 / ℃, from approximately 30×10 -7 / ℃ to approximately 40×10 -7 / ℃ or from approximately 30×10 -7 / ℃ to approximately 50×10 -7 / ℃.

[0028] In some embodiments, the exemplary glass composition essentially comprises the following components:

[0029] Approximately 60 mol% to approximately 75 mol% of SiO2;

[0030] Approximately 4 mol% to approximately 10.5 mol% of Al2O3;

[0031] Approximately 5 mol% to approximately 11 mol% of B2O3;

[0032] Approximately 3.5 mol% to approximately 15 mol% of K₂O;

[0033] 0 mol% to about 6 mol% MgO; and

[0034] SnO2 from 0 mol% to approximately 1 mol%.

[0035] The molar ratio of K2O / Al2O3 is in the range of about 0.4 to about 2, and the molar ratio of MgO / Al2O3 is in the range of 0 to about 4.

[0036] In some embodiments, the molar ratio of SiO2 / B2O3(k) can be in the range of about 6 to about 15. The R' value, defined as ([K2O]-[Al2O3]) / [B2O3], is in the range of about -0.7 to about 0.7, and the R” value, defined as ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3], is in the range of about -0.3 to about 1.3. [K2O], [MgO], [Al2O3], and [B2O3] represent the molar contents of K2O, MgO, Al2O3, and B2O3, respectively.

[0037] On the other hand, this disclosure also provides methods for manufacturing and using the glass composition described herein, glass articles (or components) comprising such glass compositions, and display devices comprising glass compositions or glass articles having the glass composition.

[0038] Examples of glass articles include, but are not limited to, panels, substrates, covers, backplates, and any other components in electronic devices for display applications. For example, in some embodiments, the glass composition or glass substrate serves as a cover or backplate in an electronic device. In some embodiments, thin-film resistors are formed on or in contact with the glass composition. Examples of electronic devices include, but are not limited to, liquid crystal displays (LCDs), light-emitting diode (LED) displays, computer monitors, automatic teller machines (ATMs), touchscreens, and photovoltaic devices. Attached Figure Description

[0039] The present disclosure can be best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, by convention, these drawings are used only to illustrate some embodiments.

[0040] Figure 1 The exemplary relationship between the content of alkali metal oxides (e.g., K2O) and liquid phase temperature in exemplary glass compositions according to some embodiments is depicted graphically.

[0041] Figure 2 The relationship between the content of alkali metal oxides (e.g., K2O) and the viscosity of the liquid phase in exemplary compositions according to some embodiments is depicted graphically. Detailed Implementation

[0042] This description of exemplary embodiments is to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. In this description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “upward,” “downward,” “top,” and “bottom,” and derivative terms of these terms (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the orientation described or shown in the drawings under discussion. These relative terms are for ease of description and do not imply that the device is constructed or operated in a particular orientation. Terms relating to attachment, coupling, etc., such as “connection” and “interconnection,” refer to a relationship in which a structure is directly or indirectly fixed or attached to another through an intermediate structure, and both may be movable or may be rigidly attached or related, unless otherwise expressly stated.

[0043] For the purposes described below, it should be understood that alternative variations and implementations may be taken of the embodiments described below. It should also be understood that the specific articles, components, and / or methods described herein are exemplary and should not be considered limiting.

[0044] In this disclosure, the singular forms “a” and “the” include plural references, and a reference to a particular numerical value includes at least that particular numerical value, unless the context clearly indicates otherwise. When a value is expressed as an approximation using the antecedent “about,” it will be understood that the particular value forms another implementation. As used herein, “about X” (where X is a numerical value) preferably refers to ±10% (inclusive) of the listed value. For example, the phrase “about 8” preferably refers to a value of 7.2 to 8.8 (inclusive of the endpoint). Where present, all ranges are inclusive and combinable. For example, when the range “1 to 5” is stated, the stated range should be interpreted as including the ranges “1 to 4,” “1 to 3,” “1 to 2,” “1 to 2 and 4 to 5,” “1 to 3 and 5,” “2 to 5,” and so on. Furthermore, when a list of alternatives is provided positively, such a list can be interpreted as meaning that any alternatives can be excluded, for example, by the negative limitations in the claims. For example, when the range “1 to 5” is specified, the specified range can be interpreted to include cases where any one of 1, 2, 3, 4 or 5 is negatively excluded; therefore, the statement “1 to 5” can be interpreted as “1 and 3 to 5” but excluding “2”, or simplified to “excluding 2”. In other words, any component, element, property or step expressly stated herein can be expressly excluded in the claims, whether such component, element, property or step is listed as an alternative or stated independently.

[0045] As used herein, the terms "substantially," "substantially," and their variations are intended to indicate that the described feature is equal to or approximately equal to a value or description. Furthermore, "substantially similar" is intended to indicate that two values ​​are equal or approximately equal. In some implementations, "substantially similar" may mean values ​​that are within approximately 10% of each other, such as within approximately 5% or approximately 2%.

[0046] This disclosure provides glass compositions comprising oxides of alkali metals (such as potassium), methods of manufacturing the same, and methods of using the same. This disclosure also provides glass substrates or articles comprising such glass compositions, and display devices comprising such glass compositions or glass substrates, said glass substrates having such glass compositions. Such glass compositions comprise the ingredients as described herein, including low amounts of Al₂O₃ and alkali metal oxides (such as K₂O). In some embodiments, K₂O is the only alkali metal oxide in the composition. As described herein, the inventors have surprisingly discovered that such glass compositions comprising alkali metal oxides and low amounts of Al₂O₃ provide low liquidus temperatures, high liquidus viscosity, low and adjustable coefficients of thermal expansion, and good mechanical properties. The inventors have also surprisingly discovered that when the compositions are used in electronic devices, alkali metal ions (such as K₂O)... + Metal ions such as K will not diffuse from the glass composition. Any potential contamination caused by the diffusion of alkali metals with ionic radii equal to or greater than K can be minimized or eliminated.

[0047] Unless otherwise expressly stated, the terms “glass articles” or “glass” as used herein shall be understood to include objects made wholly or partially of glass. Glass articles include monolithic substrates, or stacks of glass and glass, glass and non-glass materials, glass and crystalline materials, and glass and glass ceramics (including amorphous and crystalline phases).

[0048] Glass articles, such as glass panels, can be flat or curved, and are transparent or substantially transparent. As used herein, the term "transparent" is intended to mean that an article with a thickness of approximately 1 mm has a transmittance greater than about 85% in the visible light region of the spectrum (400 to 700 nm). For example, an exemplary transparent glass panel may have a transmittance greater than about 85% in the visible light range, such as greater than about 90%, greater than about 95%, or greater than about 99%, including all ranges and subranges therebetween. According to various embodiments, glass articles may have a transmittance less than about 50% in the visible region, such as less than about 45%, less than about 40%, less than about 35%, less than about 30%, less than about 25%, or less than about 20%, including all ranges and subranges therebetween. In some embodiments, the exemplary glass panel may have a transmittance greater than about 50% in the ultraviolet (UV) region (100 to 400 nm), such as greater than about 55%, greater than about 60%, greater than about 65%, greater than about 70%, greater than about 75%, greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, or greater than about 99%, including all ranges and subranges therebetween.

[0049] Exemplary glasses may include, but are not limited to: aluminosilicates, alkali metal aluminosilicates, borosilicates, alkali metal borosilicates, aluminum borosilicates, alkali metal aluminum borosilicates, and other suitable glasses. In some embodiments, glass articles can be mechanically strengthened by utilizing the mismatch in the coefficients of thermal expansion between different parts of the article to create regions of compressive stress and a central region exhibiting tensile stress. In some embodiments, glass articles can be thermally strengthened by heating the glass to a temperature above the glass transition point and then rapidly quenching it. In some other embodiments, glass articles can be chemically strengthened by ion exchange.

[0050] In some embodiments, the glass composition described herein is an alkaline earth aluminosilicate glass composition, which may include a combination of: SiO2, Al2O3, an alkaline earth oxide, and K2O (as the sole alkali metal oxide). In some embodiments, MgO is the alkaline earth oxide in the composition. The glass composition described herein has an amorphous structure. Crystalline or polycrystalline structures can also be manufactured using the composition.

[0051] As used herein, the term "softening point" refers to a glass composition with a viscosity of 1 × 10⁻⁶. 7.6 The softening point is measured using the parallel plate viscosity method.

[0052] As used herein, the term "annealing point" refers to a glass composition with a viscosity of 1 × 10⁻⁶.13.18 The temperature of the lake.

[0053] As used in this article, the terms "strain point" and "T" are used interchangeably. strain This means the viscosity of the glass composition is 10. 14.68 The temperature of the lake.

[0054] Liquidation temperature of glass (T) liq The liquid phase viscosity refers to the temperature above which no crystalline phase coexists with the glass in equilibrium. The liquid phase viscosity is the viscosity of the glass at its liquidus temperature.

[0055] As used herein, the term "CTE" refers to the coefficient of thermal expansion of a glass composition in the temperature range from about room temperature (RT) to about 300°C.

[0056] Fracture toughness can be measured using methods known in the technical field to which this case pertains, such as ASTM C1421-10, "Standard Test Method for Determining Fracture Toughness of Advanced Ceramics at Ambient Temperatures," using V-notches, short bars, notched beams, etc.

[0057] For the purposes of this disclosure, with respect to Mode I defect openings of surface defects in finite solids, the passivated crack tip can be quantitatively reduced by subtracting a value representing the defect geometry in the following formula relating failure toughness to failure stress:

[0058] K IC =σ f √{ (Ωπa) square root} Equation (1)

[0059] in

[0060] K IC For destructive toughness, a material constant,

[0061] σ f The measured stress at failure.

[0062] Ω represents the flaw geometry, free-surface effects, and form of loading, and

[0063] 'a' represents the defect depth.

[0064] The average load and failure stress of the sample are characterized. This also includes the value of the square root of √{(Ωπa)} from equation (1) above, calculated from failure data of the glass (whose composition is provided above) and known fracture toughness (approximately 0.7 MPa / m²). 0.5 The value was obtained using a V-notch test, where m is in meters. As described above, in equation (1), the expression corresponds to the breaking toughness K of the glass. IC (Unit is MPa·m) 0.5 The failure stress σ measured for each sample of this glass f The proportion (in MPa). Due to the value of the square root of √{(Ωπa)} (in m). 0.5 The value takes into account both the defect depth (a) and the defect “shape” (Ω), and therefore directly reflects the effect of the currently disclosed treatment on the flaw configuration factor, which affects the transmission characteristics of strength-limited surface defects that lead to stress failure of the glass sheet with the surface defects.

[0065] In embodiments of the glass composition described herein, unless otherwise specified, the concentration of the constituent components (e.g., SiO2, Al2O3, etc.) is specified as a mole percentage (mol%) of oxides.

[0066] When used to describe the concentration and / or absence of a particular constituent component in a glass composition, the terms "free" and "substantially free" mean that the constituent component was not intentionally added to the glass composition. However, as a contaminant or impurity, the glass composition may contain trace amounts of the constituent component in amounts less than 0.01 mol%.

[0067] This disclosure provides glass compositions containing alkali metals (such as potassium), methods for manufacturing the same, and methods for using the same. This disclosure also provides glass substrates comprising such glass compositions, and display devices comprising such glass compositions or glass substrates, wherein the glass substrate has such glass compositions.

[0068] This disclosure provides novel glass compositions intended for use in display glass applications. Based on conventional wisdom, alkali metals such as Li₂O, Na₂O, K₂O, Rb₂O, and Cs₂O are contraindicated in display glass compositions because they can diffuse into electronic components during high-temperature downstream processes, including thin-film transistor (TFT) deposition. The inventors have recently discovered that oxides of alkali metals with large ionic radii, such as K₂O, can be used in display glass compositions without diffusion. No diffusion occurs from the glass substrate to the overlying SiO₂ or SiNx barrier layer, which is deposited as the first layer on the glass substrate.

[0069] According to some embodiments, the glass composition is essentially composed of the following components:

[0070] Approximately 60 mol% to approximately 80 mol% of SiO2;

[0071] 0 mol% to approximately 11 mol% of Al2O3;

[0072] Approximately 4.0 mol% to approximately 12 mol% of B2O3;

[0073] Approximately 0.5 mol% to approximately 20 mol% of K₂O;

[0074] 0 mol% to about 18.5 mol% MgO; and

[0075] SnO2 from 0 mol% to approximately 1 mol%.

[0076] In the composition, the components are selected from the above six oxides. In some embodiments, these six oxides are the only components. K2O is the only added alkali metal oxide, and other alkali metal oxides such as Li2O and Na2O are not included or substantially not included. MgO is the only added alkaline earth metal oxide, and CaO, SrO, or BaO are not included or substantially not included.

[0077] In the embodiments of the glass composition described herein, SiO2 is the largest component of the composition and, therefore, the main component of the glass network.

[0078] The glass composition contains SiO2 in any suitable range. Suitable examples include, but are not limited to, about 60 mol% to about 75 mol%, about 65 mol% to about 80 mol%, or about 65 mol% to about 75 mol%. In some embodiments, the SiO2 content is equal to or less than 75 mol%, for example, in the range of about 60 mol% to about 75 mol%.

[0079] The glass composition described herein may further include a relatively low content of Al2O3, depending on the specific embodiment. In some embodiments, the content of Al2O3 is equal to or less than 11 mol%. Examples of suitable ranges for Al2O3 include, but are not limited to: about 0.1 mol% to about 10.5 mol%, 0.1 mol% to about 2 mol%, about 2 mol% to about 10.5 mol%, about 4 mol% to about 15 mol%, or any other suitable range.

[0080] The glass composition in the embodiments described herein also includes alkali metal oxides. Preferably, the alkali metal oxide is K₂O, which is the only added alkali metal oxide. The content of K₂O can be in any suitable range. Examples of suitable ranges for K₂O include, but are not limited to: about 0.5 mol% to about 15 mol%, about 1 mol% to about 15 mol%, about 3.5 mol% to about 15 mol%, about 3 mol% to about 15 mol%, or about 3 mol% to about 10 mol%.

[0081] When present, Al2O3 acts similarly to SiO2, and when tetrahedral coordinated in a glass melt formed from a glass composition, Al2O3 can increase the viscosity of the glass composition. However, as described in U.S. Patent No. 10,112,865, the presence of Al2O3 in a glass composition is considered to increase the migration rate of alkali components in the glass composition, and the content of Al2O3 in the glass composition needs to be carefully considered.

[0082] In U.S. Provisional Patent Application No. 62 / 856,170, filed June 3, 2019, and U.S. Provisional Patent Application No. 62 / 886,687, filed August 14, 2019, the inventors surprisingly discovered that a high content of Al2O3, together with alkali metal oxides present in the glass composition, reduces the tendency for alkali components to diffuse or leach out of the glass, or maintains the alkali components in the composition under processing conditions, wherein thin-film transistors are formed in or on a substrate containing the glass composition under said processing conditions.

[0083] The inventors of this disclosure have further and surprisingly discovered that zero percent or low content of Al₂O₃, together with K₂O present in the glass composition and other components disclosed herein, also reduces the tendency for alkaline components to diffuse or leach from the glass, or maintains the alkaline components in the composition under processing conditions, wherein thin-film transistors are formed in or on a substrate containing the glass composition under said processing conditions. Furthermore, glass compositions having alkali metal oxides such as K₂O have relatively low but adjustable thermal expansion. The relevant coefficient of thermal expansion (CTE) can be determined or adjusted according to the proportions of the components.

[0084] K₂O can be used as a primary alkali metal oxide component because its relatively large ionic radius reduces the diffusivity of alkali metals in glass compared to Na or Li. When the glass composition is used to form the backplane of a display, the low diffusivity of alkali metals from the glass into the overlying barrier layer is crucial, as diffusion of alkali metals from the glass into the thin-film transistor deposited on the glass can damage the transistor.

[0085] In some implementations, K2O is used as a flux and to lower the liquidus temperature, making the glass easier to manufacture. K2O also increases the range of coefficient of thermal expansion (CTE) to include glass compositions with low, medium, and high CTEs.

[0086] The glass composition in the embodiments described herein further comprises B2O3. Similar to SiO2 and Al2O3, B2O3 contributes to the formation of a glass network. In some embodiments, B2O3 may be added to the glass composition to reduce its viscosity. In the embodiments described herein, B2O3 is present in the glass composition in a certain amount. Examples of suitable ranges for B2O3 include, but are not limited to, from about 4.9 mol% to about 11.5 mol%, from about 6 mol% to about 11 mol%, or from about 8 mol% to about 11 mol%.

[0087] The compositions provided in this disclosure may, where appropriate, include alkaline earth metal oxides, such as MgO. In some embodiments, MgO is the only alkaline earth metal oxide added. Examples of suitable ranges for MgO include, but are not limited to: 0 mol% to about 15 mol%, 0 mol% to about 10 mol%, 0 mol% to about 6 mol%, about 0.1 mol% to about 10 mol%, 0.1 mol% to about 0.6 mol%, or about 10 mol% to about 18.5 mol%. In some embodiments, the MgO content is equal to or less than 6 mol%, for example, in the range of 0 mol% to about 2 mol%. In some embodiments, the MgO content is equal to or greater than 10 mol%, for example, in the range of about 10 mol% to about 18.5 mol% or about 16 mol% to about 18.5 mol%. MgO has high field strength and is used to increase the modulus of glass compositions.

[0088] The composition may contain any other suitable ingredient, such as SnO2. Examples of suitable ranges for SnO2 include, but are not limited to, from about 0.01 mol% to about 0.5 mol% or from about 0.05 mol% to about 0.15 mol%.

[0089] This disclosure provides for any suitable composition having different combinations of the ingredients and content ranges described herein.

[0090] In some embodiments, the molar ratio of K2O / Al2O3 is in the range of about 0.4 to about 360, for example, from about 0.4 to about 2, from about 1 to about 10, from about 1 to about 100, from about 100 to about 200, or from about 200 to about 360. In some embodiments, the K2O / Al2O3 ratio is in the range of about 1 to about 10, for example, from about 0.4 to about 2.

[0091] In some embodiments, the molar ratio of MgO / Al2O3 is in the range of 0 to about 10, for example, from 0 to about 4, or from 0 to about 1. The molar ratio of SiO2 / B2O3(k) may be in the range of about 6 to about 15.

[0092] In some embodiments, the R' value defined as ([K2O]-[Al2O3]) / [B2O3] is in the range of about -0.7 to about 0.7, and the R” value defined as ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3] is in the range of about -0.3 to about 1.3. [K2O], [MgO], [Al2O3], and [B2O3] represent the molar contents of K2O, MgO, Al2O3, and B2O3, respectively. The R' value and the range of R' values ​​indicate the proportion of residual alkali gold and alkaline earth cations after the charge of Al2O3 is balanced to transform B2O3 from a trigonal planar to a tetragonal plane. The higher the proportions of R' and R”, the more boron will be present in the glass as IV coordinated boron, which increases the Young's modulus of the glass composition.

[0093] The properties of glass components can include, from low to medium, Young's modulus, refractive index, density, strain point, annealing point, and softening point. These properties are relevant and important for display applications.

[0094] In some embodiments, at temperatures ranging from 20°C to 300°C, the coefficient of thermal expansion (CTE) of the glass composition ranges from approximately 40 × 10⁻⁶. -7 / ℃ to approximately 85×10 -7 The CTE can be adjusted according to the composition for different applications. For example, the CTE is in the following range: from approximately 40 × 10⁻⁶ °C. -7 / ℃ to approximately 80×10 -7 / ℃ or from approximately 40×10 -7 / ℃ to approximately 70×10 -7 / ℃, from approximately 40×10 -7 / ℃ to approximately 60×10 -7 / ℃, from approximately 30×10 -7 / ℃ to approximately 40×10 -7 / ℃ or from approximately 30×10 -7 / ℃ to approximately 50×10-7 / ℃. The range of CTE facilitates CTE matching for a wide range of materials, including TFTs at the low end of the CTE spectrum and alumina and metals (such as Ti) at the high end of the CTE range. If these glasses are used in laminated structures, such CTE variations can be utilized to generate compressive stresses caused by CTE mismatch during cooling.

[0095] This disclosure provides for any suitable composition having different combinations of the ingredients and content ranges described herein.

[0096] In some embodiments, the exemplary glass composition essentially comprises the following components:

[0097] Approximately 60 mol% to approximately 75 mol% of SiO2;

[0098] Approximately 4 mol% to approximately 10.5 mol% of Al2O3;

[0099] Approximately 5 mol% to approximately 11 mol% of B2O3;

[0100] Approximately 3.5 mol% to approximately 15 mol% of K₂O;

[0101] 0 mol% to about 6 mol% MgO; and

[0102] SnO2 from 0 mol% to approximately 1 mol%.

[0103] The molar ratio of K2O / Al2O3 is in the range of about 0.4 to about 2, and the molar ratio of MgO / Al2O3 is in the range of 0 to about 4.

[0104] In some embodiments, the molar ratio of SiO2 / B2O3(k) can be in the range of about 6 to about 15. The composition has an R' value defined by ([K2O]-[Al2O3]) / [B2O3] and an R” value defined by ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3], wherein the R' value is in the range of about -0.7 to about 0.7, and the R” value is in the range of about -0.3 to about 1.3. [K2O], [MgO], [Al2O3], and [B2O3] represent the molar contents of K2O, MgO, Al2O3, and B2O3, respectively.

[0105] Glass compositions offer advantages in terms of handling and performance. For example, glass compositions have a low liquidus temperature (T0). liqHigh liquid phase viscosity. The liquid phase temperature may be equal to or less than 1,300°C, for example, in the following ranges: about 900°C to 1,300°C, about 950°C to 1,300°C or about 1,000°C to 1,200°C, about 900°C to 1,185°C or about 1,000°C to 1,185°C, about 900°C to 1,150°C or about 1,000°C to 1,150°C. In some embodiments, the liquid phase temperature is below 950°C.

[0106] The glass composition has a liquid phase viscosity equal to or greater than 100 kilopoise (kPoise), for example, in the range of about 200 kPoise to about 400 kPoise, about 200 kPoise to about 600 kPoise, or about 200 kPoise to about 800 kPoise. In some embodiments, the liquid phase viscosity may be in the range of 100 kPoise to 800 kPoise, for example, from about 100 kPoise to about 550 kPoise or from about 200 kPoise to about 450 kPoise.

[0107] The glass composition disclosed herein has a refractive index in the range of about 1.4 to about 1.6 at 589.3 nm, for example, from about 1.47 to about 1.50. In some embodiments, the stress optical constant is about 3.2 nm / MPa / cm, for example, 3.253 nm / MPa / cm. The density of the glass composition is from about 2.2 g / cm³. 3 Approximately 2.4cm 3 Within that range, for example, from approximately 2.249 g / cm³ 3 Approximately 2.393cm 3 .

[0108] The strain point of the glass composition disclosed herein can range from about 520°C to about 700°C, for example, from about 522°C to about 651°C. The annealing point can range from about 550°C to about 750°C, for example, from about 580°C to about 705°C. The softening point of the glass composition can range from about 800°C to about 1,050°C, for example, from about 835°C to about 1,025°C.

[0109] The glass composition disclosed in this paper also provides good toughness. The breaking toughness K of the glass. IC (in MPa·m) 0.5 (in units) can range from approximately 0.5 MPa·m 0.5 Approximately 1 MPa·m 0.5 Within that range, for example, from approximately 0.5 MPa·m 0.5 Approximately 0.75 MPa·m 0.5 .

[0110] The Passon's ratio of the glass composition can be in the range of about 0.2 to about 0.3, for example, from about 0.20 to about 0.23; the Young's modulus can be in the range of about 50 GPa to about 80 GPa, for example, from about 53 GPa to about 73 GPa; and the shear modulus can be in the range of about 20 GPa to about 40 GPa, for example, from about 20 GPa to about 30 GPa.

[0111] On the other hand, this disclosure also provides methods for manufacturing and using the glass composition described herein, glass articles (or components) comprising such glass compositions, and display devices comprising glass compositions or glass articles having the glass composition.

[0112] Examples of glass articles include, but are not limited to, panels, substrates, covers, backplates, or any other components in electronic devices used for display applications. In some embodiments, glass articles such as substrates or panels are optically transparent. Examples of glass articles include, but are not limited to, flat or curved glass panels.

[0113] For example, in some embodiments, the glass composition or glass substrate serves as a cover or backplate in an electronic device. In some embodiments, a thin-film resistor is formed on or in contact with the glass composition. The thin-film resistor may be amorphous silicon or polycrystalline silicon. In some embodiments, the glass composition provided in this disclosure serves as a substrate or layer, and an amorphous silicon transistor is disposed in or on said substrate or layer. Examples of electronic devices include, but are not limited to, liquid crystal displays (LCDs), light-emitting diode (LED) displays, computer monitors, automatic teller machines (ATMs), touch screens, and photovoltaic devices.

[0114] Example

[0115] The following examples illustrate the methods and results based on the disclosed subject matter. These examples are not intended to include all embodiments of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of this disclosure that will be obvious to those skilled in the art to which this application pertains.

[0116] Efforts have been made to ensure the accuracy of figures (e.g., content, temperature, etc.), but some errors and biases should still be considered. Unless otherwise specified, temperatures are in °C or ambient temperature, and pressures are at or near atmospheric pressure. The components themselves are given as molar percentages based on oxides and have been normalized to 100%. Reaction conditions can be varied and combined in many ways, such as component concentrations, temperatures, pressures, and other reaction ranges and conditions that can be used to optimize the purity and yield of the products obtained from the method. Such process conditions can be optimized with only reasonable and routine experiments.

[0117] The glass properties listed in the table were determined using standard techniques in the glass industry. Therefore, x 10 -7 The coefficient of linear thermal expansion (CTE) is expressed in °C over a temperature range of 25 °C to 300 °C, and the annealing point is expressed in °C. CTE is determined according to ASTM E228. Unless otherwise explicitly specified, the annealing point and strain point are determined using beambending viscosity measurement techniques according to ASTM C598. Measurements are taken in grams per centimeter using the Archimedes method (ASTM C693). 3 The density is expressed as a constant. The melting temperature (defined as the temperature at which the glass melt exhibits a viscosity of 200 poise) is calculated using the Fulcher equation. The Fulcher equation is consistent with high-temperature viscosity data measured by rotating cylinders viscometry (ASTM C965-81).

[0118] The liquidus temperature of glass, expressed in °C, is measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing shards of glass in a platinum boat, placing the boat in a furnace with a gradient temperature zone, heating the boat for 24 hours within a suitable temperature range, and determining the highest temperature at which crystals appear inside the glass using microscopic examination. More specifically, the glass sample is removed entirely from the Pt boat and examined using polarized light microscopy to determine the location and nature of crystals formed against the platinum-air interface and within the sample. Since the furnace gradient is well-known, the temperature-to-location comparison can be easily estimated with an error within 5 to 10 °C. The temperature at which crystals are observed in the interior portion of the sample is taken as the liquidus temperature (for the corresponding test period). Sometimes, the test is performed for a longer period (e.g., 72 hours) to observe slower-growing phases. The liquidus viscosity, expressed in poise, is determined from the liquidus temperature and the coefficients of the Fulcher equation.

[0119] Young's modulus and shear modulus were expressed in GPa, and Poisson's ratio was determined using the general type of resonant ultrasonic spectroscopy technique described in ASTM E1875-00e1.

[0120] The stress optical coefficient (SOC) value can be measured using Procedure C (glass disk method) as described in ASTM standard C770-16, entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient".

[0121] The exemplary glass for the table was prepared using commercial sand as the silica source, which was ground to ensure that 90% by weight of the commercial sand passed through a standard US 100-mesh sieve. Alumina was used as the alumina source, periclase as the MgO source, and tin oxide (IV) as the SnO2 source. The raw materials were thoroughly mixed and double-melted in a crucible. Alternatively, the raw materials could be mixed and then placed in a platinum container (suspended in a furnace heated by a silicon carbide glow bar), melted and stirred for several hours at a temperature between 1600°C and 1650°C, and conveyed through an orifice at the bottom of the platinum container. The mixing and double-melting process ensured homogeneity. The resulting glass cake was annealed at or near the annealing point, and then subjected to various experimental methods to determine its physical, viscous, and liquidus properties.

[0122] These methods are not unique, and standard methods well known to those skilled in the art to which this case pertains can be used to prepare glass compositions. Such methods include continuous melting processes, such as those performed in continuous melting processes, wherein the melter used in the continuous melting process is heated by gas, electricity, or a combination thereof.

[0123] Raw materials suitable for producing exemplary glass include commercially available sand as a source of SiO2; alumina, aluminum hydroxide, hydrated forms of alumina, and various aluminosilicates, nitrates, and halides as sources of Al2O3; boric acid, anhydrous boric acid, and boron oxide as sources of B2O3; and periclase, magnesium oxide, magnesium carbonate, magnesium hydroxide, and various forms of magnesium silicate, aluminosilicates, nitrates, and halides as sources of MgO. If chemical clarifying agents are required, tin may be added in the form of SnO2, in the form of a mixed oxide with another major glass component, or under oxidizing conditions in the form of SnO, tin oxalate, tin halides, or other tin compounds known to those skilled in the art to which this application pertains.

[0124] The example glass composition contains SnO2 as a clarifying agent, but other chemical clarifying agents can also be used to obtain glass of sufficient quality for TFT substrate applications.

[0125] In addition to incorporating elements into the example glass in appropriate amounts, the properties of the final glass are finely adjusted by using small amounts of contaminants in the raw materials, by the high-temperature corrosion of refractory materials and precious metals in the manufacturing process, or by introducing small amounts of these elements. This ensures that almost all stable elements in the periodic table exist in the glass in some amount.

[0126] Hydrogen inevitably exists as hydroxide anions, OH-. - Hydroxide ions exist in the form of ions, and their presence can be determined using standard infrared spectroscopy. Dissolved hydroxide ions significantly and non-linearly affect the annealing point of the exemplary glass, and therefore, to obtain the desired annealing point, it may be necessary to adjust the concentration of the main oxide component to compensate. The concentration of hydroxide ions can be controlled to some extent by selecting the raw materials or the melting system. For example, boric acid is a major source of hydroxide ions, and replacing boric acid with boron oxide is a useful means of controlling the hydroxide concentration in the final glass. The same reasoning applies to other potential raw materials containing hydroxide ions, hydrates, or compounds containing physically or chemically adsorbed water molecules. If a burner is used in the melting process, hydroxide ions can also be introduced through combustion products from the combustion of natural gas and related hydrocarbons, and therefore it may be necessary to transfer the energy used in melting from the burner to the electrodes to compensate. Alternatively, an iterative process of adjusting the main oxide component can be used to compensate for the detrimental effects of dissolved hydroxide ions.

[0127] Sulfur is commonly found in natural gas and is also an impurity component in many carbonate, nitrate, halide, and oxide feedstocks. Sulfur can be a troublesome source of gaseous inclusions in the form of SO2. The tendency to form SO2-rich defects can be significantly controlled by adjusting the sulfur content in the feedstock and by incorporating low amounts of relatively reduced polyvalent cations into the glass matrix. While not wishing to be bound by theory, SO2-rich gaseous inclusions appear to be primarily generated through the reduction of sulfates (SO4w) dissolved in the glass.

[0128] Controlling the sulfur content in raw materials to a low level is a useful way to reduce dissolved sulfur (possibly sulfate) in glass. Specifically, the sulfur content in the batch is preferably less than 200 ppm (by weight), and more preferably less than 100 ppm (by weight).

[0129] Reduced multivalent ions can also be used to control the tendency of exemplary glasses to form SO2 bubbles (blister). While it is undesirable to be bound by theory, these elements act as potential electron donors, suppressing the electromotive force of sulfate reduction. Sulfate reduction can be represented by half-reactions, such as...

[0130] SO4 ＝→SO2+O2+2e -

[0131] Where e - Represents electrons. The equilibrium constant for this half-reaction is:

[0132] K eq =[SO2][O2][e - ] 2 SO4 ＝ ]

[0133] The parentheses indicate chemical reactivity. Ideally, a forced reaction is desired to produce SO2, O2, and 2e. - Sulfates are formed. Adding nitrates, peroxides, or other oxygen-rich feedstocks may help, but they can also prevent sulfate reduction in the early stages of melting, potentially negating any initial benefits. SO2 has very low solubility in most glasses, making its addition to the glass melting process impractical. Electrons can be "added" through the reduction of polyvalent ions. For example, ferrous (Fe) 2+ The appropriate electron-supplied half-reaction can be represented as:

[0134] 2Fe 2+ →2Fe 3+ +2e -

[0135] This "activity" of electrons can force the sulfate reduction reaction to shift to the left, thereby stabilizing SO4 in the glass. ＝ Suitable reducing polyvalent ions include, but are not limited to: Fe. 2+ Mn 2+ Sn 2+ Sb 3+ As 3+ V 3+ Ti 3+ And others familiar to those skilled in the art to which this case pertains. In each case, minimizing the concentration of these components may be important to avoid adverse effects on the glass color, or, in the case of As and Sb, to avoid adding such components at sufficiently high levels that would complicate waste management in end-user processes.

[0136] In addition to the primary oxide components and the aforementioned minor components or impurities of the exemplary glass, various amounts of halides may be present. These halides can be introduced as contaminants through the selection of raw materials or added as appropriate components to eliminate gaseous inclusions in the glass. As a clarifying agent, about 0.4 mol% or less of halides may be incorporated, although it is generally desirable to use even lower amounts to avoid corrosion of exhaust gas treatment equipment. In some embodiments, the concentration of each individual halide element is less than about 200 ppm (by weight), or less than about 800 ppm (by weight) for the sum of all halide elements.

[0137] Tables 1 to 5 summarize the composition and properties of 21 experimental samples. Table 1 shows the composition of Experimental Examples 1 to 5 (“Experimental Examples 1 to 5”). Table 2 shows the composition of Experimental Examples 6 to 10 (“Experimental Examples 6 to 10”). Table 3 shows the composition of Experimental Examples 11 to 15 (“Experimental Examples 11 to 15”). Table 4 shows the composition of Experimental Examples 16 to 21 (“Experimental Examples 16 to 21”). Examples 1 to 21 are also labeled in the order “A” to “X”. The property data of Examples 1 to 21 (including softening point, annealing point, Young's modulus, shear modulus, and Passon's ratio) are listed in Tables 1 to 4.

[0138] Table 1

[0139]

[0140]

[0141] Table 2

[0142]

[0143]

[0144] Table 3

[0145]

[0146] Table 4

[0147]

[0148]

[0149] In Table 4, “COV” is the coefficient of variation of the failure toughness data.

[0150] Figure 1 The overall trend of the effect of K2O content on the liquid phase temperature of the components disclosed herein is illustrated. Figure 2The overall trend of the relationship between K2O content and liquid phase viscosity is plotted for the components disclosed in this paper. Figure 1 and 2 In this study, experimental samples 1 to 3 (“S1”, “S2”, “S3”) were compared with a control product, which was available from Corning Incorporated (trademark EAGLE XG (“EXG”) and was K2O-free). EAGLE XG may not include other comparable components and is used herein for illustrative purposes only. The product EXG had a liquidus temperature of 1140°C and a liquidus viscosity of 228,527 poise.

[0151] The glass composition has a liquid phase viscosity equal to or greater than 100 kilopoise (kPoise). For example, the liquid phase viscosity can be adjusted to be in the following ranges: about 200 kPoise to about 400 kPoise, about 200 kPoise to about 600 kPoise, about 100 kPoise to about 550 kPoise, or about 200 kPoise to about 450 kPoise. This increased liquid phase viscosity and this decreased liquid phase temperature provide significant processing advantages and reduce manufacturing costs.

[0152] Please refer to Tables 1 through 5. The glass composition has a coefficient of thermal expansion (CTE) within an adjustable range. The exemplary glass possesses favorable properties such as annealing point and Young's modulus, making it suitable for display applications, such as AMLCD substrates, and more specifically, for low-temperature polycrystalline silicon and oxide thin-film transistor applications. The glass exhibits similar durability in acidic and alkaline media to that obtained from commercial AMLCD substrates, and is therefore suitable for AMLCD applications. The exemplary glass can be formed using a pull-down technique, and is particularly compatible with melting processes.

[0153] Furthermore, despite the use of a large amount of alkali metal oxides, no metal ions (such as alkali metal ions) leach or diffuse from the glass composition when the composition is used in electronic devices.

[0154] Although the subject matter claimed in this application has been described with reference to exemplary embodiments, the subject matter claimed in this application is not limited thereto. Rather, the appended claims should be interpreted broadly to include other variations and embodiments that can be performed by those skilled in the art to which this application pertains.

Claims

1. A glass composition comprising SiO2, Al2O3, B2O3, K2O, MgO, and SnO2, wherein the R' value of ([K2O]-[Al2O3]) / [B2O3] is in the range of -0.7 to 0.7, and the R'' value of ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3] is in the range of -0.3 to 1.3, wherein [K2O], [MgO], [Al2O3], and [B2O3] each represent the molar content of K2O, MgO, Al2O3, and B2O3, respectively, and wherein the glass composition is free of CaO, SrO, and Na2O. in, The glass composition includes: SiO2 from 60 mol% to 80 mol%; Al₂O₃ from 0.1 mol% to 11 mol%; B2O3 from 4.0 mol% to 12 mol%; MgO from 0 mol% to 18.5 mol%; K₂O from 0.1 mol% to 10 mol%; and SnO2 from 0.01 mol% to 1 mol%.

2. The glass composition of claim 1, wherein the content of Al2O3 is in the range of 4 mol% to 10.5 mol%.

3. The glass composition of claim 1, wherein the K2O content is in the range of 3 mol% to 10 mol%.

4. The glass composition of claim 1, wherein the SiO2 content is in the range of 60 mol% to 75 mol%.

5. The glass composition of claim 1, wherein the MgO content is in the range of 0.1 mol% to 10 mol%.

6. The glass composition of claim 1, wherein the content of B2O3 is in the range of 4.9 mol% to 11.5 mol%.

7. The glass composition of claim 1, wherein the molar ratio of K2O / Al2O3 is in the range of 0.4 to 360.

8. The glass composition of claim 1, wherein the molar ratio of MgO / Al2O3 is in the range of 0 to 10.

9. The glass composition of claim 1, wherein the molar ratio of MgO / Al2O3 is in the range of 0 to 4.

10. The glass composition of claim 1, wherein the molar ratio of SiO2 / B2O3 is in the range of 6 to 15.

11. The glass composition of claim 1, wherein at a temperature of 20 °C to 300 °C, the glass composition has a coefficient of thermal expansion in the range of 40 × 10⁻⁶. -7 / °C to 85×10 -7 / °C.

12. The glass composition of claim 1, wherein the glass composition is free of CaO, SrO and BaO.

13. A glass article comprising the glass composition as described in claim 1.

14. A display device comprising a glass composition as claimed in claim 1 or a glass substrate, the glass substrate comprising the glass composition as claimed in claim 1.

15. The display device of claim 14, wherein the glass composition or the glass substrate is a cover or backplate in an electronic device for a display application.

16. A glass composition comprising SiO2, Al2O3, B2O3, K2O, MgO, and SnO2, wherein the R' value of ([K2O]-[Al2O3]) / [B2O3] is in the range of -0.7 to 0.7, and the R'' value of ([K2O]+0.5*[MgO]-[Al2O3]) / [B2O3] is in the range of -0.3 to 1.3, wherein [K2O], [MgO], [Al2O3], and [B2O3] each represent the molar content of K2O, MgO, Al2O3, and B2O3, respectively, and wherein the glass composition is free of CaO, SrO, and BaO. in, The glass composition includes: SiO2 from 60 mol% to 80 mol%; Al₂O₃ from 0.1 mol% to 11 mol%; B2O3 from 4.0 mol% to 12 mol%; MgO from 0 mol% to 18.5 mol%; K₂O from 0.1 mol% to 10 mol%; and SnO2 from 0.01 mol% to 1 mol%.

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