Abstract: The present invention relates to a multilayer UV filter particle, comprising: an odd number of alternating layers of high and low refractive index materials, wherein each layer has a refractive index that differs from that of adjacent layers by at least 0.2, the total number of layers is at least 9, and the particle does not contain a substrate. The particle according to the present invention can have a good UV filtering effect.

Abstract: The present invention relates to a float glass for chemical strengthening, containing a bottom surface coming into contact with a molten metal at the time of forming and a top surface opposing the bottom surface, in which a difference ?(N—Na2O2) determined by subtracting a square of a normalized Na2O surface concentration of the bottom surface which is a value obtained by dividing an Na2O concentration in the bottom surface by an Na2O concentration at a depth position of 100 ?m therefrom, from a square of a normalized Na2O surface concentration of the top surface which is a value obtained by dividing an Na2O concentration in the top surface by an Na2O concentration at a depth position of 100 ?m therefrom, is 0.040 or less.

Abstract: A glass for chemical strengthening is a glass plate. The glass plate includes, as represented by mass percentage based on the following oxides, 65 to 72% of SiO2, 3.4 to 8.6% of Al2O3, 3.3 to 6% of MgO, 6.5 to 9% of CaO, 13 to 16% of Na2O, 0 to 1% of K2O, 0 to 0.2% of TiO2, 0.01 to 0.15% of Fe2O3 and 0.02 to 0.4% of SO3. In the glass plate, (Na2O+K2O)/Al2O3 is 1.8 to 5.

Abstract: The present invention relates to a float glass for chemical strengthening, containing a bottom surface coming into contact with a molten metal at the time of forming and a top surface opposing the bottom surface, in which a difference ?(N—Na2O2) determined by subtracting a square of a normalized Na2O surface concentration of the bottom surface which is a value obtained by dividing an Na2O concentration in the bottom surface by an Na2O concentration at a depth position of 100 ?M therefrom, from a square of a normalized Na2O surface concentration of the top surface which is a value obtained by dividing an Na2O concentration in the top surface by an Na2O concentration at a depth position of 100 ?m therefrom, is 0.040 or less.

Abstract: A front glass plate for a stacked structure includes greater than or equal to 5 mol % of Al2O3, in terms of an oxide, as a component, 50% crack initiation load of the front glass plate being greater than or equal to 0.5 kg.

Abstract: A method for producing a glass substrate includes (a) a step of forming molten glass having a temperature T2 less than or equal to 1500° C. on molten tin having an iron concentration greater than or equal to 100 ppm to produce a glass ribbon having a temperature T4 less than or equal to 1100° C. and a logarithm log ? greater than or equal to 8.8, and (b) a step of cooling the glass ribbon to room temperature to produce the glass substrate. The temperature T2 represents a temperature when a logarithm of a viscosity ? (dPa·s) is 2, the temperature T4 represents a temperature when the logarithm of the viscosity ? (dPa·s) is 4, and the logarithm log ? represents a logarithm of a volume resistivity ? (?·cm) at 150° C.

Abstract: Glasses are described which have characteristics that produce high visible transmittance, low solar transmittance, and high selectivity. The glasses can also preferably have a blue-green color. A number of advantageous formulations are described.

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: 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: To provide a production process capable of making the transmittance of an optical glass element obtainable by press-molding a TeO2-containing glass high. A process for producing an optical glass element, which comprises press-molding a TeO2-containing glass, wherein the press-molding is carried out in an atmosphere in which the nitrogen partial pressure is at most 102 Pa. The above process for producing an optical glass element, wherein the face of a mold for the press-molding to be in contact with the glass is made of carbon. The above process for producing an optical glass element, wherein the molded glass obtained by the press-molding is held in an oxygen-containing atmosphere at a temperature within a range of at least a temperature lower by 50° C. than the glass transition point of the TeO2-containing glass and at most the softening point of the glass.

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: The present invention has an object to provide an optical glass having excellent devitrification properties during high temperature forming and press moldability and capable of reducing weight and size of an optical system. The present invention relates to an optical glass comprising, in mass % on oxide basis; B2O3: 10 to 25%, SiO2: 0.5 to 12%, La2O3: 17 to 38%, Gd2O3: 5 to 25%, ZnO: 8 to 20%, Li2O: 0.5 to 3%, Ta2O5: 5 to 15% and WO3: 3 to 15, wherein (SiO2+B2O3)/(ZnO+Li2O) value which is a mass ratio of the total content of SiO2 and B2O3 to the total content of ZnO and Li2O is from 1.35 to 1.90.

Abstract: The present invention provides an optical glass including, by mass %: 46 to 70 of B2O3; 3 to 10 of Li2O; 5 to 15 of Y2O3; 0 to 46 of SiO2: 0 to 20 of Al2O3: 0 to 40 of MgO+CaO+SrO+BaO; 0 to 30 of La2O3; and 0 to 10 of ZrO2+TiO2+Gd2O3.

Abstract: An optical glass which has an internal transmittance to a light having a wavelength of 400 nm being at least 90% as calculated in a thickness of 1 mm and which contains at least 25 mol % of B2O3 and from 0.1 to 20 mol % of TeO2. The above optical glass which contains La2O3. The above optical glass wherein the glass transition point ?650° C. and the refractive index at 633 nm?1.70. A process for producing an optical element made of the above optical glass, which comprises dropping the optical glass in a molten state from a flow outlet of a flow out pipe made of a platinum alloy to form a preform and subjecting it to precision press-molding.

Abstract: The invention provides: an optical glass which comprises, in terms of % by mass on the basis of oxides, 13-27% of B2O3, 20-35% of La2O3, 5-25% of Gd2O3, 5-20% of ZnO, 0.5-3% of Li2O, 0.5-15% of Ta2O5 and 0.5-10% of WO3, wherein the value of (SiO2+B2O3)/(ZnO+Li2O), which is the mass ratio of the total content of SiO2 and B2O3 to the total content of ZnO and Li2O, is 1.35-1.65; and a lens comprising the optical glass.

Abstract: To provide an optical glass which has a high transmittance and a high refractive index and shows little decrease in the transmitted light intensity when continuously irradiated with a blue-violet laser diode light, and which is less prone to a higher melting temperature and exhibits chemical durability being not low. An optical glass consisting essentially of, as represented by mol %, from 35 to 54% of TeO2, from 0 to 10% of GeO2, from 5 to 30% of B2O3, from 0 to 15% of Ga2O3, from 0 to 8% of Bi2O3, from 3 to 20% of ZnO, from 0 to 10% of MgO+CaO+SrO+BaO, from 1 to 10% of Y2O3+La2O3+Gd2O3, from 0 to 5% of Ta2O5+Nb2O5, from 0 to 1.8% of TiO2, and from 0 to 6% of Li2O+Na2O+K2O+Rb2O+Cs2O. A lens made of such an optical glass.

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: The invention provides an optical glass comprising, by mass % on the oxide basis; 25 to 50% of B2O3; 5 to 25% of ZnO: 13 to 25% of La2O3; 10 to 28% of Gd2O3; and 1.5 to 4% of Li2O, the optical glass having: a refractive index (nd) of 1.65 to 1.76; an Abbe number (?d) of 45 to 60; and a molding temperature (Tp), as defined with the glass transition temperature (Tg) and the yield point (At) by the expression At+(At?Tg)/2, of 650° C. or less; the optical glass substantially containing neither an arsenic nor a lead nor a fluorine.

Abstract: The present invention provides an optical glass including, by mass %: 46 to 70 of B2O3; 3 to 10 of Li2O; 5 to 15 of Y2O3; 0 to 46 of SiO2: 0 to 20 of Al2O3: 0 to 40 of MgO+CaO+SrO+BaO; 0 to 30 of La2O3; and 0 to 10 of ZrO2+TiO2+Gd2O3.

Abstract: To provide a production process capable of making the transmittance of an optical glass element obtainable by press-molding a TeO2-containing glass high. A process for producing an optical glass element, which comprises press-molding a TeO2-containing glass, wherein the press-molding is carried out in an atmosphere in which the nitrogen partial pressure is at most 102 Pa. The above process for producing an optical glass element, wherein the face of a mold for the press-molding to be in contact with the glass is made of carbon. The above process for producing an optical glass element, wherein the molded glass obtained by the press-molding is held in an oxygen-containing atmosphere at a temperature within a range of at least a temperature lower by 50° C. than the glass transition point of the TeO2-containing glass and at most the softening point of the glass.