Yttria-containing glass substrate

Abstract

The glass substrate comprises about 45 mol% to about 70 mol% SiO, about 15 mol% to about 30 mol% AlO, about 7 mol% to about 20 mol% YO, and optionally 0 mol% to about 9 mol% LaO, and has a high modulus of elasticity and fracture toughness.

Description

Priority

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 62 / 863,550, filed June 19, 2019, the contents of which are relied upon and incorporated herein in their entirety by reference. [Technical field]

[0002] The present disclosure relates generally to glass compositions. More particularly, the disclosed subject matter relates to glass substrates having high modulus and fracture toughness. [Background technology]

[0003] Flat or curved substrates made of optically transparent materials such as glass are used in flat panel displays, photovoltaic devices, and other suitable applications. For display applications, thin film transistors (TFTs) may be fabricated on glass substrates. Glass compositions used in display applications must have optical transparency, good thermal and mechanical properties, and dimensional stability to meet processing and performance requirements. In addition, it is necessary to prevent diffusion of metal ions into the transistors, which can damage the thin film transistors.

[0004] Rigid glasses are also used for information recording disks, such as magnetic disks in hard disk drives (HDDs), optical disks, and memory disks. The demand for larger data storage capacity and higher performance in memory disks has also led to an increasing need for glass compositions with improved performance. Summary of the Invention [Problem to be solved by the invention]

[0005] Glass is a brittle material and can occasionally break during use. The fracture toughness of commercially used glass is typically around 0.8 MPa m 0.5There is a continuing need to have glasses with high fracture toughness to improve damage resistance and / or drop performance. [Means for solving the problem]

[0006] The present disclosure provides glass compositions, glass substrates, methods of making the same, and methods of using the same. The present disclosure also provides articles comprising such glass compositions or glass substrates, as well as devices comprising glass substrates having such glass compositions.

[0007] According to some embodiments, the glass substrate comprises: about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3, and Optionally, 0 mol % to about 9 mol % La2O3; Includes.

[0008] In some embodiments, the glass substrate comprises about 27 mol% to about 43 mol% R2O3, where R2O3 is the sum of Al2O3, Y2O3, and La2O3. Examples of suitable ranges of R2O3 content include, but are not limited to, about 28 mol% to about 40 mol%, about 30 mol% to about 40 mol%, or about 32 mol% to about 38 mol%. In some embodiments, the glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7, e.g., from about 0.5 to about 1.7, or from about 1 to about 1.5.

[0009] In the glass substrate, SiO2 is present in any suitable range, including, but not limited to, about 50 mol% to about 70 mol%, about 52 mol% to about 70 mol%, about 52 mol% to about 66 mol%, about 54 mol% to about 66 mol%, or about 60 mol% to about 66 mol%.

[0010] In some embodiments, Al2O3 has a content of 15 mol% or more. Examples of suitable ranges of Al2O3 include, but are not limited to, about 16 mol% to about 30 mol%, about 17 mol% to about 30 mol%, about 18 mol% to about 30 mol%, about 18 mol% to about 28 mol%, or about 18 mol% to about 25 mol%.

[0011] In some embodiments, Y2O3 is present in an amount of 7 mol% or more. Examples of suitable ranges of Y2O3 include, but are not limited to, about 8 mol% to about 20 mol%, about 9 mol% to about 20 mol%, about 7 mol% to about 16 mol%, about 7 mol% to about 15 mol%, about 8 mol% to about 16 mol%, or about 10 mol% to about 16 mol%.

[0012] La2O3 is optional. Examples of suitable ranges of La2O3 include, but are not limited to, about 0.1 mol% to about 9 mol%, about 1 mol% to about 9 mol%, about 2 mol% to about 9 mol%, or about 3 mol% to about 9 mol%. When the glass substrate includes La2O3, such glass substrate does not contain B2O3.

[0013] In some other embodiments, the glass substrate further comprises 0 mol % to about 6 mol % B2O3, e.g., 0.1 mol % to about 6 mol % B2O3, or 0.1 mol % to about 1 mol % B2O3. When B2O3 is added, the glass substrate is substantially free of La2O3.

[0014] The glass substrate may further include 0 mol% to about 6 mol% MgO, e.g., 0 mol% to about 5 mol%, 0 mol% to about 4 mol%, 0 mol% to about 3 mol%, about 0.1 mol% to about 5 mol%, about 0.1 mol% to about 4 mol%, or about 0.1 mol% to about 3 mol%.

[0015] The glass substrate may further include an alkali metal oxide, such as Li2O, Na2O, K2O, or a combination thereof, at 0 mol % to about 12 mol %.

[0016] In some embodiments, the difference in mole percentage of (Al2O3-R2O-RO) is in the range of about 7 to about 22, e.g., about 7.1 to about 21.6, about 10 to about 20, or about 15 to about 20. R2O comprises an alkali metal oxide selected from the group consisting of Na2O, K2O, and any combination thereof. RO comprises an alkaline earth metal oxide selected from the group consisting of MgO, SrO, BaO, and any combination thereof. The glass substrate is substantially free of CaO.

[0017] In some embodiments, the glass substrate is substantially free of Eu2O3, Nb2O3, Si3N4, WO3, ZrO4, and TiO2, in addition to CaO.

[0018] According to some embodiments, the present disclosure provides a method for producing a method for detecting a pulmonary circulation, comprising: about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3; 0 mol % to about 9 mol % La2O3; 0 mol % to about 6 mol % MgO, and 0 mol % to about 12 mol % of an alkali metal oxide selected from the group consisting of Li2O, Na2O, K2O, and combinations thereof; The present invention provides a glass substrate consisting essentially of:

[0019] The glass substrate comprises about 27 mol % to about 43 mol % R2O3, where R2O3 is the sum of Al2O3, Y2O3, and La2O3. The glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7. As described herein, La2O3, B2O3, MgO, and alkali metal oxides such as Na2O and K2O are optional. When the glass substrate comprises La2O3, such glass substrate is, in some embodiments, substantially free of B2O3.

[0020] The glass substrates provided in the present disclosure have good properties for ease of processing, as well as excellent mechanical properties, including high modulus and high fracture toughness. In some embodiments, the glass substrate has a modulus of elasticity of about 0.87 to about 2.0 MPa m 0.5 Fracture toughness (K IC The glass substrate also has a Young's modulus in the range of about 100 GPa to about 140 GPa, and a rigidity modulus in the range of about 30 GPa to about 60 GPa.

[0021] The glass substrates provided in this disclosure have an amorphous structure that provides such fracture toughness and high elastic modulus, however, in some other embodiments, the glass substrates may be fabricated with a crystalline structure to have even improved elastic modulus and fracture toughness.

[0022] In other aspects, the present disclosure also provides methods of making and using the glass substrates described herein, glass articles (or components) comprising such glass substrates, and devices comprising the glass substrates or glass articles.

[0023] Examples of glass articles include, but are not limited to, panels, substrates, information recording or memory disks, covers, backplanes, and any other components used in electronic devices. For example, in some embodiments, the glass composition or glass substrate can be used as a substrate for a memory disk, or a cover or backplane in a display device. [Brief description of the drawings]

[0024] The invention will be best understood from the following detailed description when read in conjunction with the accompanying drawings, in which it is emphasized that, according to common practice, the drawings are only for the purposes of illustrating some embodiments. [Figure 1] Graph showing the relationship between the softening point and the difference between the softening point and the strain point of example glass compositions according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] This description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which should be considered as part of the entire written description. Hereafter, for illustrative purposes, it should be understood that alternative variations and embodiments are contemplated in the embodiments described below. It should also be understood that the specific articles, compositions, and / or processes described herein are illustrative and should not be considered limiting. All documents cited in this disclosure are hereby incorporated by reference.

[0026] Open-ended terms such as "include," "including," "contain," "containing," and the like mean "comprising." These open-ended transitional phrases are used to introduce an open-ended list of elements, method steps, and the like that does not exclude additional unrecited elements or method steps. Whenever an embodiment is described with the language "comprising," it will be understood that similar embodiments in other manners described with "consisting of" and / or "consisting essentially of" are also provided.

[0027] The transitional phrase "consisting of" and variations thereof exclude any unrecited element, step, or ingredient, except for impurities normally associated therewith.

[0028] The transitional phrase "consisting essentially of" or variations thereof excludes any unrecited element, step, or ingredient, except those that do not materially change the basic or novel characteristics of the specified method, structure, or composition.

[0029] In this disclosure, nouns include plural referents and reference to a particular numerical value includes at least that particular value unless the context clearly indicates otherwise. When values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. As used herein, "about X," where X is a numerical value, preferably refers to ±10% of the recited value, inclusive. For example, the phrase "about 8" preferably refers to values ​​from 7.2 to 8.8, inclusive. All ranges, where present, are inclusive and combinable. For example, if a range of "1 to 5" is recited, the recited range should be interpreted as including ranges such as "1 to 4," "1 to 3," "1-2," "1-2 and 4-5," "1-3 and 5," "2-5," etc. Additionally, when a list of options is positively provided, such list can be interpreted to mean that any of the options may be excluded, for example, by a negative limitation in the claim. For example, if a range of "1 to 5" is recited, the recited range may be interpreted as including the situation whereby any of 1, 2, 3, 4, or 5 are negatively excluded; thus, a recitation of "1 to 5" may be interpreted as "1 and 3 through 5, but not 2," or simply "2 is not included." It is intended that any components, elements, attributes, or steps actively recited herein may be expressly excluded in the claims, regardless of whether such components, elements, attributes, or steps are listed as alternatives or whether they are listed in isolation.

[0030] As used herein, the terms "substantially," "substantially," and variations thereof are intended to refer to a described characteristic being equal or nearly equal to a value or description. Additionally, "substantially similar" is intended to indicate that two values ​​are equal or nearly equal. In some embodiments, "substantially similar" may refer to values ​​that are within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

[0031] The present disclosure provides glass compositions, methods for their manufacture, and methods for their use. The present disclosure also provides glass substrates or articles made from such glass compositions, and devices including such glass compositions or glass substrates having such glass compositions. Such glass compositions include components as described herein, including high contents of Al2O3, and Y2O3. As described herein, it has been surprisingly found that such glass compositions provide high elastic modulus and high fracture toughness in addition to other desirable properties as described herein.

[0032] In some embodiments, the substrate is optically transparent. Examples of substrates include, but are not limited to, flat or curved glass panels.

[0033] Unless the context clearly indicates otherwise, the terms "glass article" or "glass" as used herein are understood to encompass any article made in whole or in part from glass, including monolithic substrates or laminates of glass and glass, glass and non-glass materials, glass and crystalline materials, and glass and glass-ceramics (including amorphous and crystalline phases).

[0034] Glass articles, such as glass panels, may be flat or curved and are transparent or substantially transparent. As used herein, the term "transparent" is intended to indicate that the article has a transmittance of greater than about 85% in the visible region of the spectrum (400-700 nm) at a thickness of about 1 mm. For example, exemplary transparent glass panels may have a transmittance of greater than about 85% in the visible light range, such as a transmittance of greater than about 90%, greater than about 95%, or greater than about 99%, including all ranges and subranges therebetween. According to various embodiments, the glass articles may have a transmittance of less than about 50% in the visible range, 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 certain embodiments, exemplary glass panels may have a transmittance of greater than about 50% in the ultraviolet (UV) range (100-400 nm), such as a transmittance of 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.

[0035] Exemplary glasses include, but are not limited to, aluminosilicate, alkali aluminosilicate, borosilicate, alkali borosilicate, aluminoborosilicate, alkali aluminoborosilicate, and other suitable glasses. In some embodiments, the glass article may be mechanically strengthened by exploiting the mismatch in thermal expansion coefficients between portions of the article to create areas of compressive stress and a central region exhibiting tensile stress. In some embodiments, the glass article may be thermally strengthened by heating the glass above its glass transition temperature and then quenching. In some other embodiments, the glass article may be chemically strengthened by ion exchange.

[0036] As used herein, the term "softening point" refers to the point at which the viscosity of a glass composition is reduced to 1×10 7.6 The temperature at which the viscosity is in poise is called the temperature.

[0037] As used herein, the term "anneal point" refers to the point at which the viscosity of a glass composition is reduced to 1×10 13.18 The temperature at which the viscosity is in poise is called the temperature.

[0038] As used herein, "strain point" and "T 歪み The term "glass composition with a viscosity of 3×10 14.68 The temperature at which the viscosity is in poise is called the temperature.

[0039] The liquidus temperature of glass (T 液相 ) is the temperature (°C) above which crystalline phases cannot coexist in equilibrium with the glass. The liquidus viscosity is the viscosity of the glass at its liquidus temperature.

[0040] As used herein, the term "CTE" refers to the coefficient of thermal expansion of a glass composition over a temperature range from about room temperature (RT) to about 300°C.

[0041] Fracture toughness can be measured using methods known in the art, for example, using small square bars with chevron notches, notched beams, etc., according to ASTM C1421-10, "Standard Test Methods for Determination of Fracture Toughness of Advanced Ceramics at Ambient Temperature." The fracture toughness values ​​(K IC ) is Y * m"Fracture Toughness Measurement of Glass and Ceramic Materials Using Chevron-Notched Specimens," J. Am. Ceram. Soc., 71[6], C-310-C-313 (1988), except that is calculated using Equation 5 in Bubsey, RT et al., "Closed-Form Expressions for Crack-Mouth Displacement and Stress Intensity Factors for Chevron-Notched Short Bar and Short Rod Specimens Based on Experimental Compliance Measurements," NASA Technical Memorandum 83796, pp. 1-30 (October 1992).

[0042] The Young's modulus values, shear modulus, and Poisson's ratios listed in this disclosure refer to values ​​(converted to GPa) measured by resonant ultrasonic spectroscopy techniques of the general type set forth in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts."

[0043] Stress-Optical Coefficient (SOC) values ​​can be measured as set forth in Procedure C (Glass Disk Method) of ASTM Standard C770-16, entitled "Standard Test Method for Measurement of Glass Stress-Optical Coefficient."

[0044] In the glass composition embodiments described herein, concentrations of components (e.g., SiO2, Al2O3, etc.) are specified in mole percent (mol %) on an oxide basis unless otherwise specified.

[0045] The terms "free" and "substantially free," when used to describe the concentration and / or absence of a particular component in a glass composition, mean that the component is not intentionally added to the glass composition. However, the glass composition may contain trace amounts of the component as contaminants or tramps in amounts less than 0.01 mole percent.

[0046] US2014 / 0141226 discloses ion-exchangeable glasses with high hardness and high modulus, and describes that sodium aluminosilicate glasses containing yttria over a wide composition range exhibit either phase separation or devitrification. For example, according to the ternary phase diagram as shown in FIG. 1 of US2014 / 0141226, when the content of Al2O3 is in the range of about 15 mol% to about 22 mol%, and the content of yttria is greater than about 7 mol%, phase separation occurs; when the content of yttria exceeds about 22.5 mol%, devitrification occurs. US2014 / 0141226 provides glass compositions with up to 7 mol% Y2O3, thus avoiding such devitrification.

[0047] US 2018 / 0022635 discloses glass compositions and glass articles having high fracture toughness, which include one or more, and in particular two or more, metal oxides selected from the group consisting of La2O3, BaO, Ta2O5, Y2O3, and HfO2. In such glass-based articles, the Al2O3 content ranges from about 1 mol% to about 15 mol%.

[0048] The present disclosure provides a glass composition or glass substrate comprising components as described herein, including high content of Al2O3, and Y2O3. Surprisingly, it has been found that such glass compositions provide glass-based articles of good quality and with desirable properties, including high elastic modulus and high fracture toughness.

[0049] According to some embodiments, the glass substrate comprises: about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3, and Optionally, 0 mol % to about 9 mol % La2O3; Includes.

[0050] In some embodiments, the glass substrate comprises about 27 mol% to about 43 mol% R2O3, where R2O3 is the sum of Al2O3, Y2O3, and La2O3. Examples of suitable ranges include, but are not limited to, about 28 mol% to about 40 mol%, about 30 mol% to about 40 mol%, or about 32 mol% to about 38 mol%. In some embodiments, the glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7, e.g., from about 0.5 to about 1.7, or from about 1 to about 1.5.

[0051] In the glass substrate embodiments described herein, SiO2 is the largest component of the composition and therefore the major component of the glass network. SiO2 may be used to obtain the desired liquidus viscosity while at the same time offsetting the amount of Al2O3 added to the composition.

[0052] In the glass substrate, SiO2 is present in any suitable range, including, but not limited to, about 50 mol% to about 70 mol%, about 52 mol% to about 70 mol%, about 52 mol% to about 66 mol%, about 54 mol% to about 66 mol%, or about 60 mol% to about 66 mol%.

[0053] The glass substrates described herein further include a relatively high content of Al2O3. In some embodiments, Al2O3 has a content of 15 mol% or more. Examples of suitable ranges of Al2O3 include, but are not limited to, about 16 mol% to about 30 mol%, about 17 mol% to about 30 mol%, about 18 mol% to about 30 mol%, about 18 mol% to about 28 mol%, or about 18 mol% to about 25 mol%.

[0054] The glass substrate in the embodiments described herein also includes Y2O3, La2O3, or a combination thereof for high elastic modulus and high fracture toughness.

[0055] In some embodiments, Y2O3 is present in an amount of 7 mol% or more. Examples of suitable ranges of Y2O3 include, but are not limited to, about 8 mol% to about 20 mol%, about 9 mol% to about 20 mol%, about 7 mol% to about 16 mol%, about 7 mol% to about 15 mol%, about 8 mol% to about 16 mol%, or about 10 mol% to about 16 mol%.

[0056] La2O3 is optional. Examples of suitable ranges of La2O3 include, but are not limited to, about 0.1 mol% to about 9 mol%, about 1 mol% to about 9 mol%, about 2 mol% to about 9 mol%, or about 3 mol% to about 9 mol%. When the glass substrate includes La2O3, such glass substrate does not contain B2O3.

[0057] In some other embodiments, the glass substrate further comprises 0 mol% to about 6 mol% B2O3, e.g., 0.1 mol% to about 6 mol% B2O3, or 0.1 mol% to about 1 mol% B2O3. When B2O3 is added, the glass substrate is substantially free of La2O3. B2O3 and La2O3 are not added together in the same formulation.

[0058] The glass substrate may further include 0 mol% to about 6 mol% MgO, e.g., 0 mol% to about 5 mol%, 0 mol% to about 4 mol%, 0 mol% to about 3 mol%, about 0.1 mol% to about 5 mol%, about 0.1 mol% to about 4 mol%, or about 0.1 mol% to about 3 mol%.

[0059] The glass substrate may further include an alkali metal oxide such as Li2O, Na2O, K2O, or a combination thereof, at 0 mol% to about 12 mol%. Examples of suitable ranges of Li2O, Na2O, K2O, or a combination thereof include, but are not limited to, 0.1 mol% to about 12 mol%, 0.1 mol% to about 10 mol%, 0.1 mol% to about 8 mol%, and 0.1 mol% to about 5 mol%. In some embodiments, the total content of Li2O, Na2O, and K2O is less than 13%. In some embodiments, the glass substrate is substantially free of alkali metal oxides.

[0060] In some embodiments, the difference in mole percentage of (Al2O3-R2O-RO) is in the range of about 7 to about 22, e.g., about 7.1 to about 21.6, about 10 to about 20, or about 15 to about 20. R2O comprises an alkali metal oxide selected from the group consisting of Na2O, K2O, and any combination thereof. RO comprises an alkaline earth metal oxide selected from the group consisting of MgO, SrO, BaO, and any combination thereof. The glass substrate is substantially free of CaO.

[0061] In some embodiments, the glass substrate is substantially free of Eu2O3, Nb2O3, Si3N4, WO3, ZrO4, and TiO2, in addition to CaO.

[0062] According to some embodiments, the present disclosure provides a method for producing a method for detecting a pulmonary circulation, comprising: about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3; 0 mol % to about 9 mol % La2O3; 0 mol % to about 6 mol % MgO, and 0 mol % to about 12 mol % of an alkali metal oxide selected from the group consisting of Li2O, Na2O, K2O, and combinations thereof; The present invention provides a glass substrate consisting essentially of:

[0063] The glass substrate comprises about 27 mol% to about 43 mol% R2O3, where R2O3 is the sum of Al2O3, Y2O3, and La2O3. The glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7. As described herein, La2O3, B2O3, MgO, and alkali metal oxides such as Na2O and K2O are optional. In the glass substrate, La2O3 and B2O3 do not coexist.

[0064] According to some embodiments, the present disclosure provides a method for producing a method for detecting a pulmonary circulation, comprising: about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3, and about 7 mol % to about 20 mol % Y2O3; The present invention provides a glass substrate consisting essentially of:

[0065] The glass substrates provided in the present disclosure have good properties for ease of processing, as well as excellent mechanical properties, including high elastic modulus and high fracture toughness. In some embodiments, the glass substrate has a modulus of elasticity of about 0.87 MPa m 0.5 to about 2.0 MPa m 0.5 , for example, about 0.87 MPa m 0.5 to approximately 1.5 MPa m 0.5 , approx. 0.87MPa m 0.5 to approximately 1.2 MPa m 0.5 , or approximately 0.87 MPa m 0.5 to approximately 1.07 MPa m 0.5 Fracture toughness (K IC ).

[0066] In some embodiments, the glass-based article has a viscosity of about 0.87 MPa m 0.5 , about 0.9MPa m 0.5 , about 1MPa m 0.5 , about 1.1MPa m 0.5 , about 1.2MPa m 0.5 , about 1.3MPa m 0.5 , approx. 1.4MPa m 0.5 , about 1.5MPa m 0.5 , approximately 1.6 MPa m 0.5 , about 1.8MPa m 0.5 , about 2MPa m 0.5 or any range of fracture toughness values ​​between the specified values.

[0067] The glass substrate also provides a Young's modulus in the range of about 100 GPa to about 140 GPa, e.g., about 100 GPa to about 130 GPa, about 100 GPa to about 120 GPa, about 105 GPa to about 120 GPa, or about 110 GPa to about 120 GPa.

[0068] The glass substrate also has a modulus of rigidity in the range of about 30 GPa to about 60 GPa, about 35 GPa to about 50 GPa, about 39 GPa to about 50 GPa, or about 40 GPa to about 50 GPa.

[0069] In another aspect, the present disclosure also provides methods of making and using the glass substrates described herein. The glass-based articles can be prepared by methods that include melting and mixing individual oxides. However, in some embodiments, the "confusion principle" can be used to maximize the entropy of mixing, e.g., to suppress crystallization.

[0070] The glass substrates provided in this disclosure have an amorphous structure that provides such fracture toughness and high elastic modulus, however, in some other embodiments, the glass substrates may be fabricated with a crystalline structure to provide even improved elastic modulus and fracture toughness.

[0071] The present disclosure also provides a glass article (or component) comprising such a glass substrate, and a device comprising the glass substrate or a glass article having the glass substrate.

[0072] Examples of glass articles include, but are not limited to, panels, substrates, information recording or memory disks, covers, backplanes, and any other components used in electronic devices. For example, in some embodiments, the glass composition or glass substrate can be used as a substrate for a memory disk, or a cover or backplane in a display device.

[0073] The glass substrates provided in the present disclosure have high Young's modulus and high fracture toughness, as well as high hardness and a relatively low softening point with a corresponding high strain / anneal point. The Vickers hardness (VHN, 200 g load) may range from 700 to 850, such as from 750 to 850, or from 767 to 818. The corresponding strain / anneal point (Δsoftening point-strain point) may range from 190 to 300, such as from 190 to 270, with a softening point of 890 to 1050° C. The relatively low softening point is exhibited with a corresponding high strain / anneal point.

[0074] Glasses with these mechanical attributes are needed for a variety of applications ranging from memory disks, which require high Young's modulus (stiffness), to display applications. For displays, a high Young's modulus minimizes the effects of film stress, and a high strain point and anneal point minimize stress and low temperature relaxation, both of which are important when the glass undergoes subsequent processing during deposition of thin film transistors. For both of these applications, the high fracture toughness of the glass results in improved strength for a given flaw size population. The challenges that these compositions address have been addressed by using advantageous mechanical attributes in the past for many years. The present disclosure provides unique glass substrates designed to take advantage of the high cationic field strength of network modifiers to achieve high modulus, high fracture toughness, and high hardness as described herein.

[0075] The density of this glass substrate is relatively high, for example, 2.8 g / cm 3 from 3.9 g / cm 3 This glass substrate has a relatively high refractive index (up to 1.708).

[0076] The glass substrates provided in the present disclosure have a low stress optical coefficient (SOC), which is less than about 4 Brewsters, for example, in the range of about 1 Brewster to about 4 Brewsters. It will be understood by those skilled in the art that the SOC is related to the birefringence of the glass. The glass substrates may have an SOC of about 1 Brewster to about 3 Brewsters, or about 1.5 Brewster to about 2.5 Brewsters. In some embodiments, the SOC is as low as about 1.7.

[0077] In some embodiments, the glass substrate is about 10×10 -7 / ℃ to about 60×10 -7 / °C range, e.g., about 30 x 10 -7 / ℃ to about 56×10 -7 / °C range, or approximately 35 x 10 -7 / ℃ to about 55×10 -7 / °C range (22 to 300°C). EXAMPLES

[0078] The following examples are set forth below to illustrate methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of 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 modifications of the present disclosure that would be apparent to one of ordinary skill in the art.

[0079] Efforts have been made to ensure accuracy relating to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless otherwise noted, temperatures are in °C or are ambient, and pressures are at or near atmospheric. The compositions themselves are given in mole percent on an oxide basis and are normalized to 100%. There are numerous variations and combinations of reaction conditions, e.g., component concentrations, temperatures, pressures, and other reaction ranges and conditions that can be used to optimize product purity and yields resulting from the described processes. Optimization of such process conditions requires no more than reasonable routine experimentation.

[0080] The glass properties set forth in Tables 1-7 were determined according to techniques conventional in the glass art. Thus, the coefficient of linear thermal expansion (CTE) over the temperature range 25-300°C is 10× -7 CTE is expressed in °C / °C and anneal point is expressed in °C. CTE was determined according to ASTM Standard E228. Anneal point was determined by fiber stretch technique according to ASTM Standard C336 unless otherwise stated. g / cm 3 Density, in m, was measured by Archimedes method (ASTM C693). Melting temperature, in °C (defined as the temperature at which the glass melt exhibits a viscosity of 200 poise), was calculated using the Fulcher equation fitted to high temperature viscosity data measured by rotating cylinder viscometry (ASTM C965-81).

[0081] The liquidus temperature of the glass, expressed in °C, was measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing crushed glass particles in a platinum boat, placing the boat in a furnace with a gradient temperature zone, heating the boat through the appropriate temperature zone for 24 hours, and determining by microscopic examination the highest temperature at which crystals appear inside the glass. More specifically, the glass sample is removed from the Pt boat in one piece and examined using polarized light microscopy to identify the location and nature of the crystals formed relative to the Pt-air interface and inside the sample. The furnace gradient is very well known, so the temperature vs. location can be well estimated to within 5-10 °C. The temperature at which crystals are observed inside the sample is taken to represent the liquidus of the glass (for the corresponding test period). Tests are sometimes run for longer periods (e.g., 72 hours) to observe slower growing phases. The liquidus viscosity, expressed in poise, was determined from the liquidus temperature and the coefficients of the Fulcher equation.

[0082] Young's modulus values, expressed in GPa, were determined using a resonant ultrasonic spectroscopy technique of the general type described in ASTM E1875-00e1.

[0083] Exemplary glasses are shown in Tables 1-7. Exemplary glasses were prepared using commercially available sand as the silica source and ground to 90% by weight passing a standard US 100 mesh sieve. Alumina was the alumina source and periclase was the source of MgO. Y2O3, La2O3, and B2O3 were also used based on the formulation. The raw materials were double melted and stirred at temperatures between 1600°C and 1650°C for several hours to thoroughly mix and ensure homogeneity. The resulting glass patties were annealed at or near the anneal point and then various experimental methods were performed to determine physical, viscous, and liquidus properties.

[0084] These processes are not unique and the glasses in Tables 1-7 can be prepared using standard methods well known to those skilled in the art. Such processes include continuous melting processes, such as would be performed in a continuous melting process, where the melter used in the continuous melting process is heated by gas, electricity, or a combination thereof.

[0085] Suitable raw materials for making the exemplary glasses 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, boric anhydride, and boron oxide as sources of B2O3; periclase, magnesia, magnesium carbonate, magnesium hydroxide, and various forms of magnesium silicates, aluminosilicates, nitrates, and halides as sources of MgO. If a chemical fining agent is desired, tin can be added in the oxidation state as SnO2, as a mixed oxide with another major glass component (e.g., CaSnO3), or as SnO, tin oxalate, tin halides, or other compounds of tin known in the art.

[0086] The glass may also contain SnO2 as a fining agent. Other chemical fining agents may also be utilized to obtain glass of sufficient quality for TFT substrate applications. For example, the exemplary glass may use any one or combination of As2O3, Sb2O3, CeO2, Fe2O3, and halides as intentional additives to promote fining, any of which may be used in combination with the SnO2 chemical fining agent shown in the examples. Of these, As2O3 and Sb2O3 are generally recognized as hazardous substances and subject to regulation in waste streams such as those that may be generated during glass manufacturing or in the processing of TFT panels. Therefore, it is desirable to limit the concentration of As2O3 and Sb2O3, individually or in combination, to 0.005 mole % or less.

[0087] In addition to the elements intentionally included in the exemplary glasses, nearly every stable element in the periodic table is present in the glasses at some level, either through low-level contamination in the raw materials, high-temperature corrosion of refractories and precious metals during manufacturing, or through intentional introduction at low levels to fine-tune the properties of the final glass. For example, zirconium may be introduced as a contaminant through interaction with zirconium-rich refractories. As yet another example, platinum and rhodium may be introduced through interaction with precious metals. As yet another example, iron may be introduced as tramp in the raw materials or may be intentionally added to improve control of gaseous inclusions. As yet another example, manganese may be introduced for color control or to improve control of gaseous inclusions.

[0088] As yet another example, alkali may be present as a tramp component at levels up to about 0.1 mole percent of the total concentration of Li2O, Na2O, and K2O.

[0089] Hydrogen is the hydroxyl anion OH -, and its presence can be confirmed by standard infrared spectroscopy techniques. Dissolved hydroxyl ions have a significant and non-linear effect on the annealing point of the exemplary glass, and therefore it would be necessary to adjust the concentration of the major oxide components to compensate in order to obtain the desired annealing point. The hydroxyl ion concentration can be controlled to some extent by the choice of raw materials or the choice of melting system. For example, boric acid is the major source of hydroxyl, and replacing boric acid with boric oxide can be a useful means to control the hydroxyl concentration of the final glass. The same reasoning applies to other potential materials including hydroxyl ions, hydrates, or compounds containing physisorbed or chemisorbed water molecules. If burners are used in the melting process, then hydroxyl ions may also be introduced by combustion products from the combustion of natural gas and related hydrocarbons, and therefore it would be desirable to shift the energy used in melting from the burner to the electrodes to compensate. Alternatively, an iterative process of adjusting the major oxide components to compensate for the deleterious effects of dissolved hydroxyl ions may be used.

[0090] Sulfur is often present in natural gas, as well as being a tramp component in many carbonate, nitrate, halide, and oxide raw materials. Sulfur, in the form of SO2, can be a troublesome source of gaseous inclusions. The tendency to form SO2-rich defects can be managed to a large extent by controlling the sulfur levels in the raw materials and by including low levels of relatively reduced polyvalent cations in the glass matrix. Without intending to be bound by theory, it is believed that SO2-rich gaseous inclusions are primarily formed by the dissolution of sulfate ions (SO4 = ) is likely to result from the reduction of

[0091] The elevated barium concentration of the exemplary glasses appears to increase the retention of sulfur in the glass in the early stages of melting, but as noted above, the lower liquidus temperature and therefore the higher T 35k -T 液相Barium is necessary to obtain high liquidus viscosity and high viscosity. Careful control of sulfur levels in the raw materials to low levels is a useful means of reducing dissolved sulfur (presumably as sulfate ions) in the glass. In particular, sulfur is preferably less than 200 ppm by weight of the batch materials, more preferably less than 100 ppm by weight of the batch materials.

[0092] Reduced polyvalent elements can also be used to control the tendency of the exemplary glasses to form SO2 blisters. Without intending to be bound by theory, these elements act as potential electron donors that suppress the electromotive force for reducing sulfate ions. The reduction of sulfate ions is SO4 = →SO2+O2+2e - where e - represents an electron. The "equilibrium constant" for this half-reaction is K eq =[SO2][O2][e - ] 2 / [SO4 = ] where the brackets indicate chemical activity. Ideally, SO2, O2 and 2e - One would want to drive the reaction to form sulfate from . Adding nitrates, peroxides, or other oxygen rich raw materials would help, but would work against the reduction of sulfate in the early stages of melting. This would counter the benefit of adding them in the first place. SO2 has very low solubility in most glasses and is therefore difficult to implement for addition to the glass melting process. Electrons would be "added" by the reduction of polyvalent elements. For example, ferrous ion (Fe 2+ The appropriate electron-donating half-reaction for 2Fe 2+ →2Fe 3+ +2e - This is expressed as:

[0093] This "activity" of electrons drives the reduction reaction of sulfate ions to the left, reducing the amount of SO4 in the glass. =Suitable reduced polyvalent elements include, but are not limited to, Fe. 2+ , Mn 2+ , Sn 2+ , Sb 3+ , As 3+ , V 3+ , Ti 3+ As, Sb, and other elements familiar to those skilled in the art. In each case, it may be important to minimize the concentration of such components to avoid detrimental effects on the color of the glass, or, in the case of As and Sb, to avoid adding such components at high enough levels that they would complicate waste management in the end user's process.

[0094] In addition to the major oxide components of the exemplary glasses and the minor or tramp components mentioned above, halides may be present at various levels, either as contaminants introduced by the selection of raw materials, or as intentional components used to eliminate gaseous inclusions in the glass. Halides may be included at levels up to about 0.4 mole percent as fining agents, but it is generally desirable to use lesser amounts, if possible, to avoid corrosion of exhaust gas handling equipment. In some embodiments, the concentration of individual halide elements is less than about 200 ppm by weight for each individual halide, or less than about 800 ppm by weight for the sum of all halide elements.

[0095] Table 1 shows the compositions of Experimental Examples 1 to 5 ("Ex. 1 to 5"). Table 2 shows the compositions of Experimental Examples 6 to 10 ("Ex. 6 to 10"). Table 3 shows the compositions of Experimental Examples 11 to 16 ("Ex. 11 to 16"). Table 4 shows the compositions of Experimental Examples 17 to 22 ("Ex. 17 to 22"). Table 5 shows the compositions of Experimental Examples 23 to 28 ("Ex. 23 to 28"). Table 6 shows the compositions of Experimental Examples 29 to 34 ("Ex. 29 to 34"). Table 7 shows the compositions of Experimental Examples 35 to 42 ("Ex. 35 to 42").

[0096] Property data for Examples 1-42, including softening point, annealing point, Young's modulus, shear modulus, Poisson's ratio, fracture toughness, and hardness, are also listed in Tables 1-7. As can be seen from Tables 1-7, the example glasses have good properties such as high elastic modulus and high fracture toughness that make them suitable for a variety of applications, including, but not limited to, display applications such as memory disk and AMLCD substrate applications.

[0097] With reference to Figure 1, the temperature difference between the softening point and the strain point of these glasses is small relative to their softening points. The data for these glass substrates is also compared to that of common borosilicate glass, fused quartz, and soda-lime compositions. The glass compositions provided in this disclosure also offer processing advantages over common glasses.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3]

[0101] [Table 4]

[0102] [Table 5]

[0103] [Table 6]

[0104] [Table 7]

[0105] While the subject matter has been described with respect to exemplary embodiments, it is not limited thereto, but rather the scope of the appended claims should be construed broadly to include other variations and embodiments as would occur to those skilled in the art.

[0106] Preferred embodiments of the present invention will be described below in detail.

[0107] EMBODIMENT 1 about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3, and Optionally, 0 mol % to about 9 mol % La2O3; A glass substrate comprising:

[0108] EMBODIMENT 2 2. The glass substrate of embodiment 1, wherein the glass substrate comprises about 27 mol % to about 43 mol % R2O3, where R2O3 comprises Al2O3, Y2O3, and La2O3.

[0109] EMBODIMENT 3 3. The glass substrate of embodiment 2, wherein R2O3 is in the range of about 28 mol% to about 40 mol%, about 30 mol% to about 40 mol%, or about 32 mol% to about 38 mol%.

[0110] EMBODIMENT 4 2. The glass substrate of claim 1, wherein the glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7.

[0111] EMBODIMENT 5 2. The glass substrate of embodiment 1, wherein SiO2 is in the range of about 50 mol% to about 70 mol%, about 52 mol% to about 70 mol%, about 52 mol% to about 66 mol%, about 54 mol% to about 66 mol%, or about 60 mol% to about 66 mol%.

[0112] EMBODIMENT 6 2. The glass substrate of embodiment 1, wherein Al2O3 is in the range of about 16 mol% to about 30 mol%, about 17 mol% to about 30 mol%, about 18 mol% to about 30 mol%, about 18 mol% to about 28 mol%, or about 18 mol% to about 25 mol%.

[0113] EMBODIMENT 7 2. The glass substrate of embodiment 1, wherein Y2O3 is in the range of about 8 mol% to about 20 mol%, about 9 mol% to about 20 mol%, about 7 mol% to about 16 mol%, about 7 mol% to about 15 mol%, about 8 mol% to about 16 mol%, or about 10 mol% to about 16 mol%.

[0114] EMBODIMENT 8 2. The glass substrate of embodiment 1, wherein La2O3 is in the range of about 0.1 mol% to about 9 mol%, about 1 mol% to about 9 mol%, about 2 mol% to about 9 mol%, or about 3 mol% to about 9 mol%.

[0115] EMBODIMENT 9 2. The glass substrate of embodiment 1, further comprising 0 mol % to about 6 mol % B2O3 and substantially free of La2O3.

[0116] EMBODIMENT 10 2. The glass substrate of embodiment 1, further comprising 0 mol % to about 6 mol % MgO.

[0117] EMBODIMENT 11 2. The glass substrate of embodiment 1, further comprising 0 mol % to about 12 mol % of Li2O, Na2O, K2O, or a combination thereof.

[0118] EMBODIMENT 12 2. The glass substrate of embodiment 1, wherein the difference in mole percentage of (Al2O3-R2O-RO) is in the range of about 7 to about 22, where R2O comprises an alkali metal oxide selected from the group consisting of Li2O, Na2O, KO, and any combination thereof, and RO comprises an alkaline earth metal oxide selected from the group consisting of MgO, SrO, BaO, and any combination thereof.

[0119] EMBODIMENT 13 2. The glass substrate of embodiment 1, wherein the glass substrate is substantially free of CaO, Eu2O3, Nb2O3, Si3N4, WO3, ZrO4, and TiO2.

[0120] EMBODIMENT 14 Approximately 0.87 to approximately 2.0 MPa m 0.5 Fracture toughness (K IC 2. The glass substrate of embodiment 1, comprising:

[0121] EMBODIMENT 15 2. The glass substrate of embodiment 1, having a Young's modulus in the range of about 100 GPa to about 140 GPa, and a rigidity modulus in the range of about 30 GPa to about 60 GPa.

[0122] EMBODIMENT 16 about 45 mol % to about 70 mol % SiO2; about 15 mol % to about 30 mol % Al2O3; about 7 mol % to about 20 mol % Y2O3; 0 mol % to about 9 mol % La2O3; 0 mol % to about 6 mol % MgO, and 0 mol % to about 12 mol % of an alkali metal oxide selected from the group consisting of Li2O, Na2O, K2O, and combinations thereof; A glass substrate consisting essentially of:

[0123] EMBODIMENT 17 17. The glass substrate of embodiment 16, wherein the glass substrate comprises about 27 mol % to about 43 mol % R2O3, where R2O3 comprises Al2O3, Y2O3, and La2O3, and the glass substrate has a molar ratio of [(Y2O3+La2O3) / Al2O3] ranging from about 0.3 to about 1.7.

[0124] EMBODIMENT 18 A glass article comprising the glass substrate according to embodiment 1 or 16.

[0125] EMBODIMENT 19 A device comprising the glass substrate according to embodiment 1 or 16.

[0126] EMBODIMENT 20 20. The device of embodiment 19, which is an electronic device for display applications.

[0127] EMBODIMENT 21 20. The device of embodiment 19, which is an information recording disc.

Claims

1. A glass substrate comprising: About 50 mol % to about 66 mol % SiO ２ , About 15 mol % to about 30 mol % Al ２ O ３ , About 7 mol % to about 20 mol % Y ２ O ３ , and Less than 6 mol% MgO wherein the glass substrate comprises: (a) Substantially B ２ O ３ and 0.1 mol % to about 9 mol % La ２ O ３ or (b) substantially ２ O ３ and 0.1 mol % to about 6 mol % B ２ O ３ Including, CaO, HfO ２ and TiO ２ Substantially free of, and From about 27 mol % to about 43 mol % R ２ O ３ R ２ O ３ Al ２ O ３ , Y ２ O ３ , and La ２ O ３ Including, Glass substrate.

2. The glass substrate has about 28 mol % to about 43 mol % R ２ O ３ The glass substrate of claim 1 .

3. The glass substrate has a [(Y ２ O ３ +La ２ O ３ ) / Al ２ O ３ 2. The glass substrate of claim 1, wherein the molar ratio of

4. SiO ２ 2. The glass substrate of claim 1, wherein the SiO2 content is in the range of about 52 mol % to about 66 mol %, about 54 mol % to about 66 mol %, or about 60 mol % to about 66 mol %.

5. A ２ O ３ 2. The glass substrate of claim 1, wherein the SiO 2 content is in the range of about 16 mol % to about 30 mol %, about 17 mol % to about 30 mol %, about 18 mol % to about 30 mol %, about 18 mol % to about 28 mol %, or about 18 mol % to about 25 mol %.

6. Y ２ O ３ is in the range of about 8 mol % to about 20 mol %, about 9 mol % to about 20 mol %, about 7 mol % to about 16 mol %, about 7 mol % to about 15 mol %, about 8 mol % to about 16 mol %, or about 10 mol % to about 16 mol %.

7. La ２ O ３ 2. The glass substrate of claim 1, wherein the is in the range of about 0.1 mol % to about 9 mol %, about 1 mol % to about 9 mol %, about 2 mol % to about 9 mol %, or about 3 mol % to about 9 mol %.

8. 0.1 mol % to about 6 mol % B ２ O ３ Further comprising La ２ O ３ The glass substrate of claim 1 , which is substantially free of

9. 10. The glass substrate of claim 1 further comprising 0 mol % to about 5 mol % MgO.

10. 0 mol % to about 12 mol % Li ２ O, Na ２ O.K. ２ The glass substrate of claim 1 , further comprising:

11. (Al ２ O ３ -R ２ O-RO) is in the range of about 7 to about 22, where R ２ O is Li ２ O, Na ２ O.K. ２ 2. The glass substrate of claim 1, wherein RO comprises an alkali metal oxide selected from the group consisting of MgO, SrO, BaO, and any combination thereof, and RO comprises an alkaline earth metal oxide selected from the group consisting of MgO, SrO, BaO, and any combination thereof.

12. EU ２ O ３ , Nb ２ O ３ , Si ３ N ４ , W.O. ３ , and ZrO ４ The glass substrate of claim 1 , which is substantially free of

13. About 0.87 to about 2.0 MPa m ０．５ Fracture toughness in the range of ＩＣ 2. The glass substrate of claim 1 .

14. 10. The glass substrate of claim 1 having a Young's modulus in the range of about 100 GPa to about 140 GPa and a rigidity modulus in the range of about 30 GPa to about 60 GPa.

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