Abstract: The X-ray-opaque glass, which is free of BaO and PbO except for at most impurities, has a refractive index nd of from 1.50 to 1.58 and a high X-ray opacity with an aluminium equivalent thickness of at least 300%. The glass is based on a SiO2—Al2O3—SrO—R2O system with additions of La2O3 and ZrO2. The glass has very good chemical resistance and can be used, in particular, as a dental glass or as an optical glass.

Abstract: This disclosure is directed to a silica-titania-niobia glass and to a method for making the glass. The composition of the silica-titania-niobia (SiO2—TiO2—Nb2O5) glass, determined as the oxides, is Nb2O5 in an amount in the range of 0.005 wt. % to 1.2 wt. %, TiO2 in an amount in the range of 5 wt. % to 10 wt. %, and the remainder of glass is SiO2. In the method, the STN glass precursor is consolidated into a glass by heating to a temperature of 1600° C. to 1700° C. in flowing helium for 6 hours to 10 hours. When this temperature is reached, the helium flow can be replaced by argon for the remainder of the time. Subsequently the glass is cooled to approximately 1050° C., and then from 1050° C. to 700° C. followed by turning off the furnace and cooling the glass to room temperature at the natural cooling rate of the furnace.

Abstract: An optical glass having optical constants of a refractive index (nd) of 1.78 or over, an Abbe number (?d) of 30 or below, and a partial dispersion ratio (?g, F) of 0.620 or below comprises SiO2 and Nb2O5 as essential components, wherein an amount of Nb2O5 in mass % is more than 40%. The optical glass further comprising, in mass % on oxide basis, less than 2% of K2O and one or more oxides selected from the group consisting of B2O3, TiO2, ZrO2, WO3, ZnO, SrO, Li2O and Na2O wherein a total amount of SiO2, B2O3, TiO2, ZrO2, Nb2O5, WO3, ZnO, SrO, Li2O and Na2O is more than 90% and TiO2/(ZrO2+Nb2O5) is less than 0.32.

Abstract: According to one embodiment, a glass article may include SiO2, Al2O3, Li2O and Na2O. The glass article may have a softening point less than or equal to about 810° C. The glass article may also have a high temperature CTE less than or equal to about 27×10?6/° C. The glass article may also be ion exchangeable such that the glass has a compressive stress greater than or equal to about 600 MPa and a depth of layer greater than or equal to about 25 ?m after ion exchange in a salt bath comprising KNO3 at a temperature in a range from about 390° C. to about 450° C. for less than or equal to approximately 15 hours.

Abstract: Provided is a tempered glass having a compression stress layer in a surface thereof, the tempered glass comprising, as a glass composition in terms of mol %, 45 to 75% of SiO2, 3 to 15% of Al2O3, 0 to 12% of Li2O, 0.3 to 20% of Na2O, 0 to 10% of K2O, and 1 to 15% of MgO+CaO, and having a molar ratio (Al2O3+Na2O+P2O5)/SiO2 of 0.1 to 1, a molar ratio (B2O3+Na2O)/SiO2 of 0.1 to 1, a molar ratio P2O5/SiO2 of 0 to 1, a molar ratio Al2O3/SiO2 of 0.01 to 1, and a molar ratio Na2O/Al2O3 of 0.1 to 5, wherein the surface is etched partially or entirely before tempering treatment.

Abstract: Lithium silicate glass ceramics and glasses containing at least 6.1 wt.-% ZrO2 are provided which can advantageously be applied to zirconium oxide ceramics in particular by pressing-on in the viscous state and forming a solid bond with the zirconium oxide ceramics.

Abstract: The present invention relates to the glass substrate for an information recording medium comprising the following glass components: SiO2: 52 to 67; Al2O3: 8 to 20; B2O3: 0 to 6, with these three oxides FMO: 70 to 85; Li2O: 0.5 to 4; Na2O: 1 to 8; K2O: 0 to 5; and with these three oxides R2O: 5 to 15; MgO: 2 to 9; CaO: 0.1 to 5; BaO: 0 to 3; SrO: 0 to 3; ZnO: 0 to 5; and with these five oxides: 5 to 15; Y2O3: 0 to 4; La2O3: 0 to 4; Gd2O3: 0 to 4; CeO2: 0 to 4; TiO2: 1 to 7; HfO2: 0 to 2; ZrO2: 0 to 5; Nb2O5: 0.2 to 5; and Ta2O5: 0 to 5, and satisfies Li2O/R2O: 0.05 to 0.35; Li2O/FMO: 0.005 to 0.035; Li2O/(MgO+ZnO): less than 2 and Nb2O5/SiO2: 0.01 to 0.075.

Abstract: A glass substrate for information recording medium, said glass substrate being composed of an aluminosilicate glass containing 60-75% by mass of SiO2, 5-18% by mass of Al2O3, 3-10% by mass of Li2O, 3-15% by mass of Na2O and 0.5-8% by mass of ZrO2 relative to the entire glass components. The glass substrate for information recording medium contains neither As (arsenic) nor Sb (antimony), while containing at least one polyvalent element selected from the group consisting of V (vanadium), Mn (manganese), Ni (nickel), Nb (niobium), Mo (molybdenum), Sn (tin), Ce (cerium), Ta (tantalum) and Bi (bismuth). The molar ratio of the total amount of the polyvalent elements to the amount of Al2O3 is within the range of 0.02-0.20.

Abstract: A thin lithium-aluminosilicate glass is provided. The glass is suitable for three dimensional precision molding and suitable for toughening, wherein after toughening, the glass has a center tension smaller than 50 Mpa, a surface compressive stress of 600-1200 Mpa, and a bending strength of up to 500 MPa. The glass also has a transition point lower than 550° C.

Abstract: A lithium aluminosilicate glass and a method for producing such lithium aluminosilicate glass are provided. The glass has a composition, in mol %, of: SiO2 60-70; Al2O3 10-13; B2O3 0.0-0.9; Li2O 9.6-11.6; Na2O 8.2-less than 10; K2O 0.0-0.7; MgO 0.0-0.2; CaO 0.2-2.3; ZnO 0.0-0.4; ZrO2 1.3-2.6; P2O5 0.0-0.5; Fe2O3 0.003-0.100; SnO2 0.0-0.3; and CeO2 0.004-0.200. Further, the composition complies with the following relations and conditions: (Li2O+Al2O3)/(Na2O+K2O) greater than 2; Li2O/(Li2O+Na2O+K2O) greater than 0.47 and less than 0.70; CaO+Fe2O3+ZnO+P2O5+B2O3+CeO2 greater that 0.8 and less than 3, where at least four out of the six oxides are included. The glass exhibits a modulus of elasticity of at least 82 GPa and has a glass transition point below 540° C. and/or a working point below 1150° C.

Abstract: Provided is an optical glass that has desired optical properties, superior resistance to devitrification, and superior mass productivity. An optical glass is made of a SiO2—Nb2O5—TiO2-based glass having a refractive index (nd) of 1.75 to 1.95 and an Abbe's number (?d) of 15 to 35 and has an operation temperature range (?T=(temperature at 100.5 poise)?(liquidus temperature)) of 20° C. or more. The optical glass preferably contains, in percent by mass, 15% to 45% SiO2, 15% to 40% (but excluding 40%) Nb2O5 and 1% to 30% TiO2 as glass components.

Abstract: An optical glass comprising, by mass %, 12 to 40% of SiO2, 15% or more but less than 42% of Nb2O5, 2% or more but less than 18% of TiO2, (provided that Nb2O5/TiO2 is over 0.6), 0.1 to 20% of Li2O, 0.1 to 15% of Na2O, and 0.1 to 25% of K2O, and having an Abbe's number ?d of 20 to 30, a ?Pg,F of 0.016 or less and a liquidus temperature of 1,200° C. or lower.

Abstract: Alkali aluminosilicate glasses that are resistant to damage due to sharp impact and capable of fast ion exchange are provided. The glasses comprise at least 4 mol % P2O5 and, when ion exchanged, have a Vickers indentation crack initiation load of at least about 7 kgf.

Abstract: An object of the present invention is to provide a Li2O—Al2O3—SiO2 based crystallized glass with excellent bubble quality even without using As2O3 or Sb2O3 as a fining agent and a method for producing the same. The Li2O—Al2O3—SiO2 based crystallized glass of the present invention is a Li2O—Al2O3—SiO2 based crystallized glass which does not substantially comprise As2O3 and Sb2O3 and comprises at least one of Cl, CeO2 and SnO2, and has a S content of not more than 10 ppm in terms of SO3.

Abstract: Transparent, essentially colorless ?-quartz glass-ceramic materials, the composition of which is free of As2O3 and of Sb2O3, where said composition contains a specific combination of three nucleating agents: TiO2, ZrO2 and SnO2; TiO2 being present in low quantity.

Abstract: A compositional range of high strain point and/or intermediate expansion coefficient alkali metal free aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates or superstrates for photovoltaic devices, for example, thin film photovoltaic devices such as CdTe or CIGS photovoltaic devices or crystalline silicon wafer devices. These glasses can be characterized as having strain points ?600° C., thermal expansion coefficient of from 35 to 50×10?7/° C.

Abstract: Provided is a high refractive index glass, comprising, as a glass composition in terms of mass %, 0 to 10% of B2O2, 0.001 to 35% of SrO, 0.001 to 30% of ZrO2+TiO2, and 0 to 10% of La2O2+Nb2O5, having a mass ratio of BaO/SrO of 0 to 40 and a mass ratio of SiO2/SrO of 0.1 to 40, and having a refractive index nd of 1.55 to 2.3.

Abstract: To provide a substrate for information recording medium having various properties, in particular higher fracture toughness, required for application of the substrate for information recording medium of the next generation such as perpendicular magnetic recording system, etc. and a material with excellent workability for such purpose. A crystallized glass substrate for information recording medium, consisting of a crystallized glass which comprises one or more selected from RAl2O4 and R2TiO4 as a main crystal phase, in which R is one or more selected from Zn, Mg and Fe, and in which the main crystal phase has a crystal grain size in a range of from 0.5 nm to 20 nm, a degree of crystallinity of 15% or less, and a specific gravity of 3.00 or less.

Abstract: The present invention relates to an all-ceramic dental prosthesis in which a porous ceramic matrix material is infiltrated with a glass, having a solubility of <1100 ?g/cm2 according to DIN EN ISO 6872. The invention also relates to the use of niobium-containing glass having an Nb2O5 content of more than 0.1% by weight as an infiltration glass for all-ceramic dental compositions.

Abstract: The invention relates to glass-ceramics based on the lithium disilicate system which can be mechanically machined easily in an intermediate step of crystallisation and, after complete crystallisation, represent a very strong, highly-translucent and chemically-stable glass-ceramic. Likewise, the invention relates to a method for the production of these glass-ceramics. The glass-ceramics according to the invention are used as dental material.

Abstract: Ion exchangeable glass articles are disclosed. In one embodiment, a glass article formed from alkali aluminosilicate glass which may include Ga2O3, Al2O3, Na2O, SiO2, B2O3, P2O5 and various combinations thereof. The glass article may generally include about X mol % of Ga2O3 and about Z mol % of Al2O3, wherein 0?x?20, 0?z?25 and 10?(X+Z)?25. The glass article may also include from about 5 mol % to about 35 mol % Na2O, SiO2 may be present in an amount from about 40 mol % to about 70 mol % SiO2. The glass article may further include Y mol % B2O3 where Y is from 0 to about 10. The glass article may further include (10-Y) mol % of P2O5. Glass articles formed according to the present invention may be ion-exchange strengthened. In addition, the glass articles may have a low liquid CTE which enables the glass articles to be readily formed into complex shapes.

Abstract: A housing/enclosure/cover can include an ion-exchanged glass exhibiting the following attributes (1) radio, and microwave frequency transparency, as defined by a loss tangent of less than 0.03 and at a frequency range of between 15 MHz to 3.0 GHz; (2) infrared transparency; (3) a fracture toughness of greater than 0.6 MPa·m1/2; (4) a 4-point bend strength of greater than 350 MPa; (5) a Vickers hardness of at least 450 kgf/mm2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (6) a Young's Modulus ranging between about 50 to 100 GPa;; (7) a thermal conductivity of less than 2.0 W/m° C., and (9) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

Abstract: Provided are a glass substrate for information recording media wherein air bubbles can be sufficiently removed, and an information recording medium using the glass substrate. The glass substrate contains 65 to 90 mass % of SiO2+Al2O3+B2O3 (where SiO2 is 45 to 75 mass %, Al2O3 is 1 to 20 mass %, and B2O3 is 0 to 8 mass %), 7 to 20 mass % of R2O (where R represents Li, Na, or K), 0.1 to 12 mass % of R?O (where R? represents Mg, Ca, Sr, Ba, or Zn), and 0.5 to 10 mass % of TiO2+ZrO2. Moreover, the glass substrate contains at least one multivalent element selected from among a group consisting of V, Mn, Ni, Mo, Sn, Ce, and Bi; the molar ratio of the total amount of the oxide of the multivalent element to the total amount of TiO2+ZrO2 is within the range of 0.05 to 0.50.

Abstract: A glass for a display substrate composed of 50 to 70% SiO2, 10 to 25% Al2O3, 8.4 to 20% B2O3, 0 to 10% MgO, 6 to 15% CaO, 0 to 10% BaO, 0 to 10% SrO, 0 to 10% ZnO, 0 to 5% TiO2, 0 to 5% P2O5, 0.01 to 0.2% alkali metal, and from 0.01% to less than 0.4% ZrO2, as expressed in % by mass. The glass can have a ?-OH value of 0.20/mm or more and an area of 0.1 m2 or more. The glass is produced by mixing raw materials to provide the SiO2, Al2O3, B2O3, MgO, CaO, BaO, SrO, ZnO, TiO2, P2O5 and alkali metal contents, electrically melting the raw materials in a melting furnace constructed of a high zirconia refractory; and refining, homogenizing and forming the glass melt.

Abstract: The invention relates to a glass ceramic comprising article, wherein the integral, non-post-processed and non-reworked glass ceramic comprising article comprises at least three different types of microstructures. The microstructures differ in the number and/or size of the crystallites contained per unit volume, and/or in the composition of the crystallites, and/or in the composition of the residual glass phases. The different microstructures are characterized by different relative ion content profiles across a cross-section perpendicular to the transition areas. The relative ion content profiles are determined from intensities which are determined using secondary ion mass spectrometry, and each of the three different types of microstructures preferably has different intensity plateaus for individual ions, wherein the individual ions are components of the main crystal phases.

Abstract: Glasses comprising SiO2, Al2O3, and P2O5 that are capable of chemical strengthened by ion exchange and having high damage resistance. These phosphate-containing glasses have a structure in which silica (SiO2) is replaced by aluminum phosphate (AlPO4) and/or boron phosphate (BPO4).

Abstract: An optical glass having a refractive index (nd) within a range from 1.825 to 1.870, an Abbe number (?d) within a range from 22 to less than 27, a transformation temperature (Tg) within a range from 530° C. to 585° C. and an mean coefficient of linear thermal expansion (?) within a range from 80×10?7° C.?1 to 103×10?7° C.?1, comprising SiO2, TiO2, Nb2O5 and Li2O and being substantially free of a Pb compound.

Abstract: An aspect of the present invention relates to a glass substrate for a magnetic recording medium, which is comprised of glass comprising, denoted as molar percentages, 56 to 75 percent of SiO2, 1 to 11 percent of Al2O3, more than 0 percent but equal to or less than 4 percent of Li2O, equal to or more than 1 percent but less than 15 percent of Na2O, equal to or more than 0 percent but less than 3 percent of K2O, and substantially no BaO, with a total content of Li2O, Na2O, and K2O falling within a range of 6 to 15 percent, with a molar ratio (Li2O/Na2O) being less than 0.50, with a molar ratio {K2O/(Li2O+Na2O+K2O)} being equal to or less than 0.13, with a total content of MgO, CaO, and SrO falling within a range of 10 to 30 percent, with a total content of MgO and CaO falling within a range of 10 to 30 percent, with a molar ratio {(MgO+CaO)/(MgO+CaO+SrO)} being equal to or more than 0.

Abstract: The present invention relates to a method of fabricating an improved lithium silicate glass ceramic and to that material for the manufacture of blocks for dental appliances using a CAD/CAM process and hot pressing system. The lithium silicate material has a chemical composition that is different from those reported in the prior art with 1 to 10% of germanium dioxide in final composition. The softening points are close to the crystallization final temperature of 800° C. indicating that the samples will support the temperature process without shape deformation.

Abstract: Mineral materials selected from lithium aluminosilicate glasses containing vanadium, precursors of glass-ceramics, and glass-ceramics colored by vanadium contain solid solution(s) of ?-quartz and/or ?-spodumene as main crystalline phase. Also disclosed are articles made from said mineral materials, as well as methods for forming said glasses, glass-ceramics and articles of said glasses and glass-ceramics. Methods involve optimizing the refining of lithium aluminosilicate glasses containing SnO2 as a fining agent in preparing glasses or glass-ceramics.

Abstract: According to one aspect of the present invention, provided is glass for use in substrate for information recording medium, which comprises, denoted as molar percentages, a total of 70 to 85 percent of SiO2 and Al2O3, where SiO2 content is equal to or greater than 50 percent and Al2O3 content is equal to or greater than 3 percent; a total of equal to or greater than 10 percent of Li2O, Na2O and K2O; a total of 1 to 6 percent of CaO and MgO, where CaO content is greater than MgO content; a total of greater than 0 percent but equal to or lower than 4 percent of ZrO2, HfO2, Nb2O5, Ta2O5, La2O3 Y2O3 and TiO2; with the molar ratio of the total content of Li2O, Na2O and K2O to the total content of SiO2, Al2O3, ZrO2, HfO2, Nb2O5, Ta2O5, La2O3, Y2O3 and TiO2 ((Li2O+Na2O+K2O)/(SiO2+Al2O3+ZrO2+HfO2+Nb2O5+Ta2O5+La2O3+Y2O3+TiO2)) being equal to or less than 0.28.

Abstract: A process for producing a wipe-proof anti-reflection layer on a borosilicate glass body is described, in which the borosilicate glass body is coated with a coating solution having a composition of 1-6% by weight of HCl, 0.5-7% by weight of SiO2 sol (solids content), 0.5-5% by weight of H2O, and 85-98% by weight of a readily volatile water-soluble organic solvent. The borosilicate glass body that is to be coated contains, in % by weight based on oxide content: 63-76 of SiO2, >11-20 of B2O3, 1-9 of Al2O3, 3-12 of alkali metal oxide(s), 0-10 of alkaline earth metal oxide(s), 0-2 of ZnO, 0-5 of TiO2, 0-1 of ZrO2, 0-1 of Nb2O5, and 0-1 of WO3.

Abstract: For providing glasses and glass-ceramics having properties suitable for use as a substrate of an information storage medium of next generation such as one for the perpendicular magnetic recording system without employing arsenic and antimony components which adversely affect human beings and the environment, there are provided glass-ceramics comprising SiO2, Li2O and Al2O3 on oxide basis, comprising lithium disilicate as a crystal phase, and comprising one or more elements selected from the group consisting of Sn, Ce, Mn, W, Ta, Bi, Nb, S, Cl and F.

Abstract: A bioactive glass composition, a method and an implant. The glass composition comprising SiO2, Na2O, K2O, CaO, and P2O5, having the following composition: SiO2 48-52 wt-%, Na2O 9-15 wt-%, K2O 12-18 wt-%, CaO 10-16 wt-%, P2O5 1-7 wt-%, TiO2 0.2-2 wt-%, B2O3 0-4 wt-%, and MgO 0-6 wt-%, wherein Na2O+K2O>25 wt-%, MgO+CaO>14 wt-%, and B2O3/P2O5>0.3.

Abstract: An alumino-borosilicate glass for the confinement, isolation of a radioactive liquid effluent of medium activity, and a method for treating a radioactive liquid effluent of medium activity, wherein calcination of said effluent is carried out in order to obtain a calcinate, and a vitrification adjuvant is added to said calcinate.

Abstract: An ion exchangeable glass that is free of lithium and comprising 0.1-10 mol % P2O5 and at least 5 mol % Al2O3. The presence of P2O5 enables the glass to be ion exchanged more quickly and to a greater depth than comparable glasses that do not contain P2O5.

Abstract: An aircraft transparency in a glass piece, wherein the glass piece includes a chemically tempered first major surface and a chemically tempered opposite second major surface, a first case depth begins at the first major surface, a second case depth begins at the second major surface, and a tensile stress zone is within the glass piece between the end points of the first and the second case depths. The glass between the end points of the first and second case depth has a glass composition including: Ingredient Percent by weight SiO2 60 to 75; Al2O3 18 to 28; and Li2O 3 to 9, and the glass has at least one of the following properties (a) a log 10 viscosity temperature of at least 1413° F. and (b) a liquidus temperature of at least 2436° F.

Abstract: An optical glass having optical constants of a refractive index (nd) of 1.78 or over, an Abbe number (?d) of 30 or below, and a partial dispersion ratio (?g, F) of 0.620 or below comprises SiO2 and Nb2O5 as essential components, wherein an amount of Nb2O5 in mass % is more than 40%. The optical glass further comprising, in mass % on oxide basis, less than 2% of K2O and one or more oxides selected from the group consisting of B2O3, TiO2, ZrO2, WO3, ZnO, SrO, Li2O and Na2O wherein a total amount of SiO2, B2O3, TiO2, ZrO2, Nb2O5, WO3, ZnO, SrO, Li2O and Na2O is more than 90% and TiO2/(ZrO2+Nb2O5) is less than 0.32.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: An optical glass having optical constants of a refractive index (nd) of 1.78 or over, an Abbe number (?d) of 30 or below, and a partial dispersion ratio (?g, F) of 0.620 or below comprises SiO2 and Nb2O5 as essential components, wherein an amount of Nb2O5 in mass % is more than 40%. The optical glass further comprising, in mass % on oxide basis, less than 2% of K2O and one or more oxides selected from the group consisting of B2O3, TiO2, ZrO2, WO3, ZnO, SrO, Li2O and Na2O wherein a total amount of SiO2, B2O3, TiO2, ZrO2, Nb2O5, WO3, ZnO, SrO, Li2O and Na2O is more than 90% and TiO2/(ZrO2+Nb2O5) is less than 0.32.

Abstract: A glass for a display substrate composed of 50 to 70% SiO2, 10 to 25% Al2O3, 8.4 to 20% B2O3, 0 to 10% MgO, 6 to 15% CaO, 0 to 10% BaO, 0 to 10% SrO, 0 to 10% ZnO, 0 to 5% TiO2, 0 to 5% P2O5, 0.01 to 0.2% alkali metal, and from 0.01% to less than 0.4% ZrO2, as expressed in % by mass. The glass can have a ?-OH value of 0.20/mm or more and an area of 0.1 m2 or more. The glass is produced by mixing raw materials to provide the SiO2, Al2O3, B2O3, MgO, CaO, BaO, SrO, ZnO, TiO2, P2O5 and alkali metal contents, electrically melting the raw materials in a melting furnace constructed of a high zirconia refractory; and refining, homogenizing and forming the glass melt.

Abstract: Zirconium-containing BaO- and PbO-free X-ray opaque glasses having a refractive index nd of about 1.54 to about 1.58 and a high X-ray opacity with an aluminum equivalent thickness of at least about 500% are provided. Such glasses are based on a SiO2—B2O3—Al2O3—R2O—RO—La2O3—ZrO2 system with optional additions of SnO2. Such glasses may be used, in particular, as dental glasses or as optical glasses.

Abstract: The optical glasses designated to be used in the areas of imaging, sensors, microscopy, medical technology, digital projection, photolithography, laser technology, wafer/chip technology as well as telecommunications, optical communications engineering and optics/illumination in the automotive sector with a refractive index nd of 1.60?nd?1.72 and/or an Abbe number vd of 32?vd?45 and with a Tg of 567° C. to 640° C., pronounced short flint character, good chemical resistance, excellent resistance to crystallization, good solarization stability and the following composition (in % by weight based on oxides): SiO2 30-45 B2O3 ?8-12 Na2O ?8-15 CaO 0.1-7?? ZnO 0 ? 5 ZrO2 10-20 Nb2O5 12-24 Ta2O5 0 ? 9 AgO ?0 ? 5.

Abstract: An aspect of the present invention relates to glass for a magnetic recording medium substrate, which comprises, denoted as molar percentages, 50 to 75 percent of SiO2, 0 to 5 percent of Al2O3, 0 to 3 percent of Li2O, 0 to 5 percent of ZnO, a total of Na2O and K2O of 3 to 15 percent, a total of MgO, CaO, SrO, and BaO of 14 to 35 percent, a total of ZrO2, TiO2, La2O3, Y2O3, Yb2O3, Ta2O5, Nb2O5, and HfO2 of 2 to 9 percent, with a molar ratio of {(MgO+CaO)/(MgO+CaO+SrO+BaO)} falling within a range of 0.85 to 1, and a molar ratio of {Al2O3/(MgO+CaO)} falling within a range of 0 to 0.30.

Abstract: A glass substrate for information recording medium, said glass substrate being composed of an alminosilicate glass containing 60-75% by mass of SiO2, 5-18% by mass of Al2O3, 3-10% by mass of Li2O, 3-15% by mass of Na2O and 0.5-8% by mass of ZrO2 relative to the entire glass components. The glass substrate for information recording medium contains neither As (arsenic) nor Sb (antimony), while containing at least one polyvalent element selected from the group consisting of V (vanadium), Mn (manganese), Ni (nickel), Nb (niobium), Mo (molybdenum), Sn (tin), Ce (cerium), Ta (tantalum) and Bi (bismuth). The molar ratio of the total amount of the polyvalent elements to the amount of Al2O3 is within the range of 0.02-0.20.

Abstract: A glass substrate for information recording medium, said glass substrate being composed of an alminosilicate glass containing 60-75% by mass of SiO2, 5-18% by mass of Al2O3, 3-10% by mass of Li2O, 3-15% by mass of Na2O and 0.5-8% by mass of ZrO2 relative to the entire glass components. The glass substrate for information recording medium contains neither As (arsenic) nor Sb (antimony), while containing at least one polyvalent element selected from the group consisting of V (vanadium), Mn (manganese), Ni (nickel), Nb (niobium), Mo (molybdenum), Sn (tin), Ce (cerium), Ta (tantalum) and Bi (bismuth). The molar ratio of the total amount of the polyvalent elements to the amount of ZrO2 is within the range of 0.05-0.50.

Abstract: The provided are a glass for a magnetic recording medium substrate permitting the realization of a magnetic recording medium substrate affording good chemical durability and having an extremely flat surface, a magnetic recording medium substrate comprised of this glass, a magnetic recording medium equipped with this substrate, and methods of manufacturing the same. Glasses for a magnetic recording medium substrate are, glass I comprised of an oxide glass, comprising, denoted as mass percentages: Si 20 to 40 percent, Al 0.1 to 10 percent, Li 0.1 to 5 percent, Na 0.1 to 10 percent, K 0 to 5 percent (where the total content of Li, Na, and K is 15 percent or less), Sn 0.005 to 0.6 percent, and Ce 0 to 1.2 percent; the Sb content is 0 to 0.1 percent; and not comprising As or F; glass II comprised of oxide glass, comprising, as converted based on the oxide, denoted as molar percentages: SiO2 60 to 75 percent, Al2O3 1 to 15 percent, Li2O 0.1 to 20 percent, Na2O 0.

Abstract: An optical glass has a refractive index (nd) of 1.60 or over and excellent transmittance and internal quality. The optical glass comprises 0.1-4 mass % of Ta2O5 to total mass of glass calculated on oxide basis, has ratio of 0.95<Ta2O5/(Ta2O5+(ZrO2)+TiO2+Nb2O5+WO3)×5)?1.00, and further comprises SiO2+B2O3+Al2O3+BaO in a total amount of 81% or over.

Abstract: A glass composition for chemical tempering includes oxides in wt % ranges of: SiO2 60 to 75; Al2O3 18 to 28; Li2O 3 to 9; Na2O 0 to 3; K2O 0 to 0.5; CaO 0 to 3; MgO 0 to 3; ZrO2 0 to 3; where MgO+CaO is 0 to 6 wt %; Al2O3+ZrO2 is 18 to 28 wt %, and Na2O+K2O is 0.05 to 3.00 wt %. The glass has a log 10 viscosity temperature in the temperature range of 1328° F. (720° C.) to 1499° F. (815° C.); a liquidus temperature in the temperature range of 2437° F. (1336° C.) to 2575° F. (1413° C.), and a log 7.6 softening point temperature in the temperature range of 1544° F. (840° C.) to 1724° F. (940° C.). The chemically tempered glass has, among other properties, an abraded modulus of rupture of 72 to 78 KPSI, and a modulus of rupture of 76 to 112 KPSI.

Abstract: The present invention relates to glass compositions for use in formation of polycarboxylate cements and polycarboxylate cements comprising these glasses, wherein the glasses comprise SiO2 and MgO, with a molar percentage of SiO2 not exceeding 60% and a molar percentage of MgO being greater than 20%.