Abstract: An optical glass for precision molding having a high refractive index (nd) and a low yield temperature (At). The optical glass comprises, as glass components in wt %, 64 to 83% of Bi2O3; 4 to 17% of B2O3; 0 to 12% of GeO2 (wherein the total of B2O3 and GeO2 is 10 to 20%); 0 to 7% of La2O3; 0 to 7% of Gd2O3 (wherein the total of La2O3 and Gd2O3 is 1 to 13%); 0 to 4% of ZrO2; 0 to 5% of Ta2O5; 0 to 15% of ZnO; 0 to 2% of Sb2O3; and 0 to 1% of In2O3. The optical glass has optical constants, that is, a refractive index (nd) of 2.05 to 2.25 and an Abbe number (vd) of 15 to 22, and a yield temperature (At) of 510° C. or less.

Abstract: [Problems to be Solved] To provide a high-refractivity low-dispersion optical glass that enables the stable production of high-quality optical elements. [Means to Solve the Problems] An optical glass comprising, as essential components, 20 to 50% of B3+, 5 to 35% of La3+, 1 to 30% of Nb5+, 0.5 to 15% of Ta5+, and 11 to 40% of Zn2+, the total content of B3+ and Si4+ being 20 to 50%, the total content of La3+, Gd3+ and Y3+ being 5 to 35%, the cationic ratio of ((B3++Si4+)/(La3++Gd3++Y3+)) being from 1 to 5, the total content of Ti4+, Nb5+, Ta5+ and W6+ being 10 to 35%, the cationic ratio of ((Nb5++Ta5+)/(Ti4++Nb5++Ta5++W6+)) being from 0.7 to 1, the cationic ratio of ((B3++Si4+)/(Ti4++Nb5++Ta5++W6+)) being from 0.5 to 4, the cationic ratio of ((La3++Gd3++Y3+)/(Ti4++Nb5++Ta5++W6+)) being from 0.2 to 3, the cationic ratio of Zn2+/Zn2++Mg2++Ca2++Sr2++Ba2+) being from 0.8 to 1, the optical glass having a refractive index nd of 1.89 or more and an Abbe's number ?d of 27 to 37.

Abstract: Provided is an optical glass having high-refractivity low-dispersion properties, having a low glass transition temperature and having the property of being softened at a low temperature so that a preform therefrom is precision press-moldable, and the optical glass comprises, as essential components, B2O3, La2O3, Gd2O3 and ZnO and has a refractive index (nd) of over 1.86, an Abbe's number (?d) of less than 35 and a glass transition temperature (Tg) of 630° C. or lower.

Abstract: The optical glass of the invention comprising: SiO2: 10 to 30%, B2O3: 15 to 35%, Li2O: 0 (inclusive) to 10%, Na2O: 0 (inclusive) to 5%, and K2O: 0 (inclusive) to 5% provided that Li2O+Na2O+K2O: 0 to 15%; MgO: 0 (inclusive) to 25%, CaO: 0 (inclusive) to 25%, BaO: 0 (inclusive) to 25%, SrO: 0 (inclusive) to 25%, and ZnO: 18 to 55% provided that MgO+CaO+BaO+SrO+ZnO: 18 to 55%; and La2O3: 5 to 20%. This optical glass does not substantially contain poisonous materials such as lead and arsenic. This optical glass has given optical constants, has a low Tg, a low TL and a good devitrification resistance, and is suitable for press molding.

Abstract: A high-refractivity low-dispersion optical glass of which the Ta2O5 content is suppressed is provided, the optical glass comprising, by mass %, 1 to 30% of B2O3, 0.1 to 20% of SiO2, 55 to 75% of a total of La2O3, Gd2O3, Y2O3 and Yb2O3, the content of La2O3 being 15 to 55%, the mass ratio of the content of Gd2O3 to the total content of La2O3, Gd2O3, Y2O3 and Yb2O3, Gd2O3/La2O3+Gd2O3+Y2O3+Yb2O3), being 0.17 to 0.65, 0 to 13% of Ta2O5 (exclusive of 13%), and 0 to 25% of a total of Nb2O5, TiO2, WO3 and ZrO2, the content of Nb2O5 being less than 10%, and having a refractive index nd of 1.83 to 1.92 and an Abbe's number ?d of 36 to 45.

Abstract: Glass-ceramic sealant is disclosed for planar solid oxide fuel cells. The glass-ceramic sealant includes 0 to 40 mol % of silicon oxide, 0 to 15 mol % boron oxide, 0 to 10 mol % of aluminum oxide, 0 to 40 mol % of barium oxide, 0 to 15 mol % of calcium oxide, 0 to 15 mol % of lanthanum oxide and 0 to 5 mol % of zirconium dioxide. At 0° C. to 600° C., the thermal expansion coefficient of the sealant is 8 to 10 ppm/° C.

Abstract: An optical glass composition contains, in % by weight, 1.0% or more and 12.0% or less of SiO2, 8.0% or more and 18.0% or less of B2O3, 0% or more and 6.0% or less of ZnO, 1.0% or more and 10.0% or less of ZrO2, 25.0% or more and 47.0% or less of La2O3, 0% or more and 5.0% or less of R2O (here, R is at least one of Li, Na and K), 0% or more and 15.0% or less of Nb2O5, 0% or more and 7.0% or less of TiO2, 0% or more and 15.0% or less of Ta2O5, 1.0% or more of Nb2O5+TiO2+Ta2O5, 0% or more and 25.5% or less of Gd2O3, 0.5% or more and 15.0% or less of WO3 and 0.5% or more and 26.0% or less of Gd2O3+WO3, and has nd of 1.88 or higher and 1.92 or lower and ?d of 33 or higher and 37 or lower, and a preform and an optical element are formed from the optical glass composition.

Abstract: Glass has optical constants of a refractive index (nd) of 1.79 or over and an Abbe number (?d) of 27 or over and a specific gravity (D) of 3.20 or over and is free from devitrification in the interior of the glass in a reheat test. The glass has chemical durability according to the Powder Method (acid-proof property RA according to the Powder Method) which is Class 1.

Abstract: An optical glass composition contains, in % by mole, 14.0% or more and 31.0% or less of SiO2, 19.0% or more and 40.0% or less of B2O3, 0% or more and 5.0% or less of Li2O, 0% or more and 12.0% or less of ZnO, 0% or more and 12.0% or less of ZrO2, 15.0% or more and 26.0% or less of La2O3, 22.0% or more and 38.0% or less of La2O3+ZrO2, 2.0% or more and 5.0% or less of Ta2O5 and 4.0% or more and 16.0% or less of Gd2O3, and has nd of 1.83 or higher and 1.87 or lower and ?d of 43 or higher and 47 or lower, and a preform and an optical element are formed from the optical glass composition.

Abstract: Lead-free acid-resistant glass composition includes 5-25% of SiO2, 4-30% of B2O3, 7-30% of ZnO, 15-70% of Bi2O3, 0-15% of Al2O3, 5-20% of BaO in weight percentage, and being substantially lead-free.

Abstract: An optical glass has optical constants of a refractive index (nd) within a range from 1.73 to less than 1.80 and an Abbe number (?d) within a range from 43 to 55, comprises SiO2, B2O3, Y2O3, La2O3, ZnO and Li2O as essential components, is substantially free of lead component, arsenic component and fluorine component, has a ratio of SiO2/B2O3 of 0.30 to 1.55 and a ratio of Y2O3/La2O3 of 0.15 to 1.00, and has a glass transition temperature (Tg) of 620° C. or below.

Abstract: An optical glass comprising, by mol %, 0.1 to 40% of SiO2, 10 to 50% of B2O3, 0 to 10% of total of Li2O, Na2O and K2O, 0 to 10% of total of MgO, CaO, SrO and BaO, 0.5 to 22% of ZnO, 5 to 50% of La2O3, 0.1 to 25% of Gd2O3, 0.1 to 20% of Y2O3, 0 to 20% of Yb2O3, 0 to 25% of ZrO2, 0 to 25% of TiO2, 0 to 20% of Nb2O5, 0 to 10% of Ta2O5, over 0.1% but not more than 20% of WO3, 0 to less than 3% of GeO2, 0 to 10% of Bi2O3, and 0 to 10% of Al2O3, the mass ratio of the content of SiO2 to the content of B2O3, SiO2/B2O3, being 1 or less, the optical glass having a refractive index nd of 1.86 to 1.95 and an Abbe's number ?d of (2.36?nd)/0.014 or more but less than 38.

Abstract: Optical glass containing bismuth oxide having good defoamability. The Optical glass contains, as % by mass, from 10 to less than 90% of a Bi2O3 component and at least 0.1% of a TeO2 and/or SeO2 component. The optical glass is on Grade 4 to Grade 1 in “JOGIS12-1994, Method for Measuring Bubbles in Optical Glass”. By controlling the amount of RO component (R is at least one selected from a group consisting of Zn, Ba, Sr, Ca, Mg) and Rn2O component (Rn?Li, Na, K, Cs), the clarifying time may be shortened.

Abstract: Provided is an optical glass comprising, denoted as molar percentages: 10 to 20 percent SiO2, 5 to 40 percent B2O3, SiO2+B2O3=15 to 50 percent, 0 to 10 percent Li2O, 12 to 36 percent ZnO, where 3×Li2O+ZnO?18 percent, 5 to 30 percent La2O3, 0 to 20 percent Gd2O3, 0 to 10 percent Y2O3, La2O3+Gd2O3=10 to 30 percent, La2O3/SIGMA(?)RE2O3=0.67 to 0.95 (where SIGMA(?)RE2O3=La2O3+Gd2O3+Y2O3+Yb2O3+Sc2O3+Lu2O3), 0.5 to 10 percent ZrO2, 1 to 15 percent Ta2O5, 1 to 20 percent WO3, Ta2O5/WO3?2.5 (molar ratio), 0 to 8 percent Nb2O5, 0 to 8 percent TiO2; and having a refractive index nd of not less than 1.87 and an Abbé number nu(v)d of not less than 35 but less then 40. A method for manufacturing a preform for precision press molding by separating a glass melt gob from a glass melt obtained by mixing, heating, and melting glass starting materials, and forming a preform in a glass melt gob cooling step, said mixing, heating, and melting of glass starting materials is conducted so as to obtain the above optical glass.

Abstract: An optical glass includes, in percent by weight, 2-11% SiO2, 28-45% B2O3, 2-15% CaO, 3-18% ZnO, 1-8% ZrO2, 9-40% La2O3, 0.5-11% Gd2O3, 0-10% Y2O3, 0-3% Al2O3, at most 8% R2O, where R2O is selected from the group consisting of Li2O, Na2O and K2O, at most 20% R?O, where R?O is selected from the group consisting of MgO, CaO, SrO and BaO, 0-3% WO3, 0-2% Nb2O5, and 0-1% Sb2O3. The optical glass is free from environmental and human harmful components such as PbO and As2O3. The optical glass has a refractive index in the range of 1.66-1.72, an Abbe number in the range of 51-56, a liquidus temperature (LT) of at most 1000° C. and a raw material melting temperature of at most 1300° C. The optical glass is suitable for mass production, and is stable against devitrification during manufacturing of preforms and precision molding of lenses.

Abstract: The invention concerns a glaze for annealing surfaces, particularly of ceramic parts used in the field of medicine, comprising the components 30 to 55% SiO2, 0 to 7% Al2O3, 10 to 30% R2O, 5 to 10% R?O, 0.5 to 15% B2O3, 5 to 10% Bi2O3, 1 to 10% P2O5, 0 to 5% Sb2O3, 0 to 5% SnO2, 0 to 5% TiO2 and 5 to 10% ZrO2 by mass, wherein (R) is one or several alkali metals and (R?) is one or several bivalent metals from the group comprising alkaline earth metals and zinc, and wherein the glaze is obtained by melting or sintering the components.

Abstract: The present invention relates to an optical glass containing, in terms of mass % on the basis of oxides, B2O3: 10 to 20%, SiO2: 0.5 to 12%, ZnO: 5 to 19%, Ta2O5: 2.5 to 17%, Li2O: 0.2 to 3%, ZrO2: 0.6 to 4.9%, WO3: 1 to 20%, La2O3: 25 to 50%, Gd2O3: 0 to 13%, and Y2O3: 0.2 to 20%, provided that La2O3+Gd2O3+Y2O3 is 35 to 60%, in which the optical glass does not substantially contain Nb2O5, and has a refractive index (nd) of 1.82 to 1.86, an Abbe's number (?d) of 37 to 44 and a glass transition point (Tg) of 630° C. or lower.

Abstract: An optical glass having high refractivity and a low sag temperature and having a low-temperature softening property that enables precision press-molding is provided, and the optical glass contains, by mol %, 5 to 50% of B2O3, 3 to 50% of SiO2, 5 to 40% of TiO2, 1 to 40% of ZnO, 5 to 20% of La2O3, 0 to 10% of Gd2O3, 0 to 15% of Nb2O5, 0 to 10% of ZrO2, 0 to 5% of Ta2O5, 0 to 10% of Bi2O3, 0 to 10% of MgO, 0 to 8% of CaO, 0 to 10% of SrO, 0 to 10% of BaO, provided that the total content of MgO, CaO, SrO and BaO is 15% or less, 0 to 20% of Li2O, and 0 to 5% of Na2O, optionally containing Sb2O3 as a refining agent, and having a refractive index (nd) of 1.8 or more and an Abbe's number (?d) of 35 or less.

Abstract: An optical glass for press-molding contains as glass ingredients, by weight: 0.5-4% SiO2; 20-30% B2O3; 10-20% ZnO; 1-10% ZrO2; 30-45% La2O3; 5-12% Nb2O5; 1-15% WO3; 0.5-3.5% TiO2; 0.5-3% CaO; 0.1-0.5% Li2O; 0-0.4% Na2O (zero inclusive); and 0-0.4% K2O (zero inclusive), with the total content of Li2O+Na2O+K2O accounting for 0.1-0.5%.

Abstract: An optical glass includes, by weight: 1% or more and 5% or less of silicon oxide (SiO2); 15% or more and 24% or less of boron oxide (B2O3); 0.1% or more and 3% or less of aluminum oxide (Al2O3); 1% or more and 14% or less of zinc oxide (ZnO); 35% or more and 45% or less of lanthanum oxide (La2O3); 5% or more and 10% or less of yttrium oxide (Y2O3); 5% or more and 13% or less of tantalum oxide (Ta2O5); and 0.5% or more and 3% or less of lithium oxide (Li2O).

Abstract: An optical glass in which a Cr content is less than 5 ppm, or a Sm content is 3 ppm or less, with respect to a 100% basic glass composition containing 2-10% SiO2, 5-45% B2O3, 0-15% RO (R?Zn, Sr, Ca, Ba), 30-60% La2O3, 0-40% Ln2O3 (Ln=Y, Gd), and, 0-30% ZrO2+Nb2O5+Ta2O5 by weight, and an optical apparatus which is provided with an optical system having the optical glass.

Abstract: An optical Glass characterized by comprising, denoted as molar percentages: B2O3 5 to 45 percent; Li2O 0 to 3 percent; ZnO 10 to 40 percent; La2O3 5 to 30 percent; Gd2O3 0 to 20 percent; and at least one from among TiO2, Nb2O5, WO3, and Bi2O3; in that the total content X of Ti, Nb, W, and Bi, denoted as a cation percentage, is 3 to 35 percent; in that the Abbé number v(nu)d and refractive index nd fall within the range delimited by sequentially connecting with straight lines points A, B, C, D and A in FIG. 1; and in that the glass transition temperature Tg satisfies relation (1) below: Tg[° C.]?655° C.?5×X??(1). An optical Glass characterized by comprising, denoted as molar percentages: B2O5 5 to 45 percent; SiO2 0 to 6 percent (excluding 6 percent); Li2O, Na2O, K2O in total 0 to 3 percent; ZnO 10 to 40 percent; La2O3 5 to 30 percent; Gd2O3 0 to 20 percent; and ZrO2, TaO2, TiO2, Nb2O5, 12.

Abstract: An object of the invention is to provide an optical glass for precision press having optical properties of a high refractive index and a low dispersion property and having a low molding temperature, a high devitrification resistance, an excellent molding property, and a small specific gravity. The optical glass of the invention contains, in terms of % by mass on the basis of oxides, respective components of B2O3: 10 to 20%, SiO2: 0.5 to 12%, La2O3: 25 to 50%, Gd2O3: 0 to 20%, Y2O3: 0 to 20%, provided that La2O3+Gd2O3+Y2O3: 35 to 60%, ZnO: 5 to 20%, Li2O: 0.2 to 3%, ZrO2: 0 to 0.5%, Ta2O5: 3 to 18% and WO3: 3 to 20%, and has optical constants of a refractive index nd of 1.84 to 1.86 and an Abbe number vd of 37 to 42 and a glass transition point (Tg) of 630° C. or lower.

Abstract: The lead-free and arsenic-free optical glasses have a refractive index of 1.83?nd?1.95 and an Abbé number of 24??d?35, good chemical resistance, excellent crystallization stability and a composition, in wt. % based on oxide content, of SiO2, 2-8; B2O3, 15-22; La2O3, 35-42; ZnO, 10-18; TiO2, 9-15; ZrO2, 3-10; Nb2O5, 4-10; and WO3, >0.5-3. Besides containing at most 5 wt. % of each of GeO2, Ag2O and BaO and conventional fining agents, they may also contain at most in total 5 wt. % of Al2O3, MgO, CaO, SrO, P2O5 and up to at most in total 5 wt. % of the components F, Ta2O5. The glasses are preferably free of alkali metal oxides, Bi2O3, Y2O3, Gd2O3 and/or Yb2O3. Optical elements made from the optical glass are also described.

Abstract: Glass for covering electrodes, which consists essentially of, as represented by mol % based on the following oxides, from 25 to 60% of B2O3, from 0 to 18% of SiO2, from 0 to 60% of ZnO, from 0 to 18% of BaO, from 3 to 15% of Bi2O3 and from 0 to 10% of Al2O3, and contains no PbO.

Abstract: Optical glass having a refractive index (nd) of 1.75 or greater, and an Abbe number (?d) falling within the range of 15 to 40, which is suitable for molding by precision mold press is provided. The optical glass is characterized by including B2O3+SiO2 in an amount of 10 to 70%, Bi2O3 in an amount of 5% or more and less than 25%, RO+Rn2O in an amount of 5 to 60% (wherein R represents one or more selected from a group consisting of Zn, Ba, Sr, Ca, and Mg; and Rn represents one or more selected from a group consisting of Li, Na, K, and Cs), with each component in the range expressed in oxide-based mole, and is characterized in that transparency in the visible region is high, and that the transition point (Tg) is 520° C. or lower. The optical glass is characterized by having a spectral transmittance of 70% or greater at a wavelength of 550 nm, for a thickness of 10 mm.

Abstract: Al2O3-rare earth oxide-ZrO2/HfO2 ceramics (including glasses, crystalline ceramics, and glass-ceramics) and methods of making the same. Ceramics according to the present invention can be made, formed as, or converted into glass beads, articles (e.g., plates), fibers, particles, and thin coatings. The particles and fibers are useful, for example, as thermal insulation, filler, or reinforcing material in composites (e.g., ceramic, metal, or polymeric matrix composites). The thin coatings can be useful, for example, as protective coatings in applications involving wear, as well as for thermal management. Certain ceramic particles according to the present invention can be are particularly useful as abrasive particles.

Abstract: An optical glass composition contains, in % by mole, 0% or more and 25.0% or less of SiO2, 20.0% or more and 40.0% or less of B2O3, 0% or more and 5.0% or less of Li2O, 3.0% or more and 15.0% or less of ZnO, 0% or more and 10.0% or less of ZrO2, 2.0% or more and 7.0% or less of Ta2O5, 6.0% or more and 25.0% or less of La2O3, 5.0% or more and 22.0% or less of Gd2O3, 66.5% or less of La2O3+Gd2O3+B2O3 and 26.0% or more of La2O3+Gd2O3, and has nd of 1.83 or higher and 1.86 or lower, vd of 43 or higher and 46 or lower and a liquidus temperature of 1300° C. or lower, and a preform and an optical element are formed from the optical glass composition.

Abstract: An optical glass contains as glass ingredients, by weight: 0-8% SiO2; 34.5-46% B2O3; 2.6-6% Li2O; 21-38% ZnO; 0-40% La2O3; 0-35% Gd2O3; and 0-15% Y2O3, with the total content of La2O3+Gd2O3+Y2O3 accounting for 10-40%. The optical glass also has a predetermined index of refraction and a predetermined dispersion.

Abstract: An optical glass which has an Abbe's number (?d) of 50 to 59, has the property of not easily reacting with a press mold, a low-temperature softening property, excellent glass stability and high refractivity, and is suitable for precision press-molding. The optical glass comprising B2O3 and SiO2 as essential components and having a B2O3 and SiO2 total content (B2O3+SiO2) of 45 to 70 by mol % and an SiO2 content/B2O3 content molar ratio (SiO2/B2O3) of from 0.1 to 0.5, the optical glass further comprising, by mol %, 5 to 15% of La2O3, 0.1 to 8% of Gd2O3, provided that the total content of La2O3 and Gd2O3 is 8% or more, 0 to 10% of Y2O3, 3 to 18% of Li2O, provided that the molar ratio of the content of Li2O to the total content of B2O3 and SiO2 [Li2O/(B2O3+SiO2)] is over 0 but not more than 0.2, 0.

Abstract: An optical glass contains as glass ingredients, by weight: 10-35% SiO2; 8-30% B2O3; 4-9% Li2O; 26-40% ZnO; 1-25% La2O3; and 6-22% Nb2O5.

Abstract: A high-refractivity low-dispersion optical glass that can be stably supplied and has excellent glass stability and that has coloring reduced, comprises, by mass %, 5 to 32% of total of SiO2 and B2O3, 45 to 65% of total of La2O3, Gd2O3 and Y2O3, 0.5 to 10% of ZnO, 1 to 20% of total of TiO2 and Nb2O5, 0 to 15% of ZrO2, 0 to 2% of WO3, 0 to 20% of Yb2O3, 0 to 10% of total of Li2O, Na2O and K2O, 0 to 10% of total of MgO, CaO, SrO and BaO, 0 to 12% of Ta2O5, 0 to 5% of GeO2, 0 to 10% of Bi2O3, and 0 to 10% of Al2O3, wherein the mass ratio of the content of SiO2 to the content of B2O3, (SiO2/B2O3), is from 0.3 to 1.0, and the mass ratio of the total content of Gd2O3 and Y2O3 to the total content of La2O3, Gd2O3 and Y2O3, (Gd2O3+Y2O3)/(La2O3+Gd2O3+Y2O3), is from 0.05 to 0.6, the optical glass having a refractive index nd of 1.89 to 2.0 and an Abbe's number ?d of 32 to 38 and having a coloring degree ?70 of 430 nm or less.

Abstract: A glass composition consisting essentially of, based on mole percent, 46-56% B2O3, 0.5-8.5% P2O5, SiO2 and mixtures thereof, 20-50% CaO, 2-15% Ln2O3 where Ln is selected from the group consisting of rare earth elements and mixtures thereof; 0-6% M?2O where M? is selected from the group consisting of alkali elements; and 0-10% Al2O3, with the proviso that the composition is water millable.

Abstract: Disclosed is an optical glass having a high refractive index and high moldability. An optical glass according to an embodiment of the invention includes Bi2O3, B2O3, SiO2, Al2O3, and ZnO and satisfies the following Conditional expressions 1 and 2: X+Y?75 ??(1), and 2.5<X/Y<13 ??(2) where X indicates the content (wt %) of Bi2O3 and Y indicates the content (wt %) of B2O3. When Conditional expression 1 is satisfied, it is possible to avoid crystallization and ensure high transparency. If the ratio is greater than the lower limit of Conditional expression 2, the refractive index nd of the optical glass with respect to the d-line is equal to or greater than 1.9. If the ratio is less than the upper limit of Conditional expression 2, it is easy to perform vitrification.

Abstract: The optical glass has a refractive index of equal to or greater than 1.65 and an Abbé number ranging from 50 to 60. In the optical glass, as molar basis, a ratio of SiO2 content to B2O3 content is greater than 0.5 and equal to or less than 0.90; a total content of SiO2 and B2O3 ranges from 50 to 70 percent; Li2O content ranges from 5 to 20 percent; La2O3 content ranges from 0.5 to 22 percent; a ratio of ZnO content to RO (MgO, CaO, SrO and BaO) is equal to or greater than 0.5; a total content of Gd2O3, Y2O3 and Yb2O3 ranges from 1 to 15 percent; Sb2O3 content ranges from 0 to 1 percent; and no BaO is comprised, or a ratio of the total content of La2O3, Gd2O3, Y2O3 and Yb2O3 to the content of BaO is equal to or greater than 10.

Abstract: An optical glass is provided that includes a refractive index (nd) of no less than 1.75 and an Abbe number (vd) of no less than 10 as optical constants. A Bi2O3 content is no less than 10% by weight to no more than 80% by weight. The content of SiO2 is lower than the content of B2O3. The total content of SiO2+B2O3 is from no less than 1% by weight to no more than 60% by weight. The content of RO is from no less than 0.1% by weight to no more than 50% by weight. R represents one or more elements selected from the group consisting of Zn, Ba, Sr, Ca, and Mg. The optical glass has at least one of the properties of being substantially free from opacification and/or being substantially devitrified within the glass body under the conditions of a reheating testing.

Abstract: Provided is an optical glass having high-refractivity low-dispersion properties, having a low glass transition temperature and having the property of being softened at a low temperature so that a preform therefrom is precision press-moldable, and the optical glass comprises, as essential components, B2O3, La2O3, Gd2O3 and ZnO and has a refractive index (nd) of over 1.86, an Abbe's number (vd) of less than 35 and a glass transition temperature (Tg) of 630° C. or lower.

Abstract: An optical glass comprising SiO2, B2O3 and La2O3 and one or more oxides selected from the group consisting of ZrO2, Nb2O5 and Ta2O5, having a refractive index of 1.83 or over and an Abbe number of 35 or over and being free of F.

Abstract: An optical glass includes a substance A generating light of a wavelength ?2 when irradiated with light of a wavelength ?1 and a substance B generating light of a wavelength ?3 when irradiated with light of the wavelength ?1 in the case where the optical glass includes 5-50 ppm Fe with respect to a 100% basic glass composition containing at least, 2-10% SiO2, 5-45% B2O3, and 30-60% La2O3, by weight, or the relation of the wavelength ?1, the wavelength ?2, and the wavelength ?3 is assumed to be ?1<?2<?3 with respect to a 100% basic glass composition containing; at least, 2-10% SiO2, 5-45% B2O3, 30-60% La2O3, 0-15% RO (R—Zn, Sr, Ba), 0-40% Ln2O3 (Ln=Y, Gd), and 0-30% total of ZrO2+Nb2O5+Ta2O5, by weight.

Abstract: [Problems to be Solved] To provide an optical glass having a very high refractive index in spite of its low-dispersion property, having excellent glass stability and having less susceptibility to coloring. [Means to Solve the Problem] An optical glass that is an oxide glass and that comprises, by cationic %, 0 to 30% of Si4+, 10 to 55% of B3+, less than 5% of total of Li+, Na+ and K+, less than 5% of total of Mg2+, Ca2+ and Sr2+, 0 to 8% of Ba2+, 0.1 to 15% of Zn2+, 10 to 50% of La3+, 0 to 20% of Gd3+, 0 to 15% of Y3+, 0 to 10% of Yb3+, 0 to 20% of Zr4+, 0.1 to 22% of Ti4+, 0 to 20% of Nb5+, 0 to 8% of Ta5+, 0 to 5% of W6+, 0 to 8% of Ge4+, 0 to 10% of Bi3+, and 0 to 10% of Ai3+, the cationic ratio of the content of Si4+ to the content of B3+, Si4+/B3+, being less than 1.0, the total content of Nb2O5 and Ta2O5 as oxides being less than 14 mass %, the optical glass having a refractive index nd of 1.92 to 2.2 and an Abbe's number ?d of 25 to 45.

Abstract: The lead-free, fluorine-free and arsenic-free optical glass, which is useful in mapping, projection, telecommunication, optical communication engineering, and mobile drive and laser technology, has a refractive index of 1.75?nd?1.83, an Abbe number of 34?Vd?44, and Tg?560° C. The glass is free of WO3 and TeO2and has a composition in percent by weight based on oxide content of: SiO2, 0.5-8; B2O3, 10-25; ZnO, 10-22; La2O3, 23-34; Ta2O5, >15-25; Nb2O5, 0.5-15; Al2O3, 0-2; and can include optional ingredients, e.g. alkali and/or alkaline-earth oxides. In addition, a sum of B2O3 and ZnO is 33 to 41% by weight and preferably a sum of La2O3+Ta2O5+Nb2O5+Y2O3+ZrO2 is greater than 50% by weight.

Abstract: This invention provides an optical glass including, by mass %: 30 to 40% of B2O3; 2.5 to 6% of Li2O; 10 to 17% of ZnO; 12 to 22% of La2O3; 15 to 25% of Gd2O3; 0 to 5% of SiO2; 0 to 5% of Bi2O3; 0 to 15% of Al2O3; 0 to 3% of ZrO2; 0 to 5% of WO3; 0 to 5% of Ta2O5; 0 to 3% of TiO2; 0 to 5% of Y2O3; and 0 to 5% of MgO+CaO+SrO+BaO.

Abstract: A glass material for mold pressing, comprising a core portion comprised of an optical glass with a degree of abrasion FA of 200 or higher and a covering portion comprised of a second glass covering at least a portion of the surface of said core portion. A method for manufacturing an optical glass element, wherein a glass material that has been preformed to a prescribed shape is heat softened and press molded with a pressing mold and the outer perimeter portion of the molded product obtained is removed by mechanical processing. The above-mentioned glass material for mold pressing is used as the glass material. To provide a means whereby an optical element does not bear scratches on optically functional surfaces through contact during handling after the press molding of press molded glass products despite being comprised of a glass material with a high degree of abrasion, and a means whereby even when scratched, the function of the optical element finally obtained is unaffected.

Abstract: A powder composition for forming a highly expansible crystallized glass substantially free of alkali metals is disclosed, which composition can provide, through its firing at a temperature of not more than 900° C., a seal between metal and ceramic. The powder composition is a powder composition for the formation of a sealing crystallized glass which is substantially free of alkali metals and consists of the powder of a glass containing, calculated as oxides, SiO2: 10-30% by mass, B2O3: 20-30% by mass, CaO: 10-40% by mass, MgO: 15-40% by mass, BaO+SrO+ZnO: 0-10% by mass, La2O3: 0-5% by mass, Al2O3: 0-5% by mass, and RO2: 0-3% by mass (wherein R represents Zr, Ti, or Sn), wherein the crystallized glass that is formed by firing the powder composition at 900±50° C. has a coefficient of thermal expansion of 90-120×10?7/° C. at 50-550 ° C.

Abstract: An optical glass suitable for precision molding glass preform having a low glass transition temperature and optical characteristics such as a high refractive index and low dispersion is provided. The optical glass contains, as essential components, cationic components of Si4+, B3+, Zn2+, La3+, Ta5+, Ga3+, and W6+ and has a refractive index (nd) of 1.8-1.9 and an abbe number (?d) of 35-42, thus less causing striae and devitrification during fusion discharge.

Abstract: Provided is an optical glass having high-refractivity low-dispersion properties, having a low glass transition temperature and having the property of being softened at a low temperature so that a preform therefrom is precision press-moldable, and the optical glass comprises, as essential components, B2O3, La2O3, Gd2O3 and ZnO and has a refractive index (nd) of over 1.86, an Abbe's number (vd) of less than 35 and a glass transition temperature (Tg) of 630° C. or lower.

Abstract: An optical glass having a remarkably high refractive index and excellent stability can be give without being based on PbO, and the optical glass contains, as essential components, at least one oxide selected from La2O3, Gd2O3, Y2O3, Yb2O3, TiO2, Nb2O5 or WO3, at least one oxide selected from MgO, CaO, SrO or BaO and B2O3 and optionally containing SiO2, wherein on the basis of mass, the total content of B2O3 and SiO2 is from 1 to 25%, the ratio of (B2O3+SiO2)/(La2O3+Gd2O3+Y2O3+Yb2O3+TiO2+Nb2O5+WO3) is from 0.05 to 0.3 and the ratio of (MgO+CaO+SrO+BaO)/(La2O3+Gd2O3+Y2O3+Yb2O3+TiO2+Nb2O5+WO3) is from 0.1 to 0.4, the optical glass having a refractive index (nd) of 2.000 or more and an Abbe's number (vd) of 27 or less.

Abstract: An optical glass having optical constants of a refractive index (nd) within a range from 1.50 to 1.65 and an Abbe number (? d) within a range from 50 to 65 and a glass transition temperature (Tg) of 400° C. or below wherein the shortest wavelength (? 80) at which transmittance is 80% is 370 nm or below.

Abstract: A family of glasses from the rare earth alumino-silicate (RE2O3—Al2O3—SiO2) ternary system exhibiting high strain point and low liquidus temperatures; preferably the La2O3—Al2O3—SiO2 ternary system. The glasses are excellent candidates for electronics applications and have the following composition, expressed in mole percent and calculated from the glass batch on an oxide basis: 60-85% SiO2, 10-25% Al2O3, and 4-15% RE2O3.

Abstract: The present invention relates to preparing an improved lithium silicate glass ceramic for the manufacture of blocks for dental appliance fabrication using a CAD/CAM process. The lithium silicate material has a chemical composition that is different from those reported in the prior art including 8 to 10% of germanium dioxide in the 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. The resulting material has improved castability and higher density.