32results about How to "Excellent glass stability" patented technology

An optical glass has a low glass transition temperature (Tg) and optical constants in which a refractive index (nd) is in the range of from 1.70 to less than 1.74 and an Abbe number (νd) is between 40 and 45 (excluding 40 and 45), has a content of SiO2 is 17% by mass or less, a glass transition temperature (Tg) is 540° C. or less, and a weathering resistance (surface-method) in Class 1 or 2, and has excellent chemical durability, particularly weathering resistance (surface-method) and is appropriate for precision mold press forming.

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, and0 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 νd of (2.36−nd) / 0.014 or more but less than 38.

The present invention relates to an optical glass having optical constants in the form of a refractive index nd of 1.70 or higher and an Abbé number nud of 50 or higher, a preform for precision press molding comprised of this glass, an optical element comprised of this glass, and methods for manufacturing the preform and the optical element.

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(Σ)RE2O3=0.67 to 0.95(where SIGMA(Σ)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; andhaving a refractive index nd of not less than 1.87 andan 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.

The optical glass of the present invention has a refractive index nd of 1.70 or greater and an Abbé number of 50 or greater. Given as mole percentages, it comprises:B2O320 to 80 percent,SiO20 to 30 percent,Li2O1 to 25 percent;ZnO0 to 20 percent,La2O34 to 30 percent,Gd2O31 to 25 percent,Y2O30 to 20 percent,ZrO20 to 5 percent,MgO0 to 25 percent,CaO0 to 15 percent,SrO0 to 10 percent,with the combined quantity of the above components being 97 percent or greater. The molar ratio of {ZnO / (La2O3+Gd2O3+Y2O3)} is 0.8 or less and the molar ratio of {(CaO +SrO+BaO) / (La2O3+Gd2O3+Y2O3)} is 0.8 or less. Ta2O5 may be incorporated as an optional component, with the molar ratio {(ZrO2+Ta2O5) / (La2O3+Gd2O3+Y2O3)}being 0.4 or less. The present invention further relates to a preform for precision press molding comprised of this glass, an optical element comprised of this glass, and methods of manufacturing the same.

A glass for magnetic recording medium substrate is an amorphous oxide glass. In terms of mol %, SiO2 content ranges from 45 to 68%, Al2O3 from 5 to 20%, total content of SiO2 and Al2O3 60 to 80%, B2O3 from 0 to 5%, MgO from 3 to 28%, CaO from 0 to 18%, total content of BaO and SrO 0 to 2%, total content of alkali earth metal oxides from 12 to 30%, total content of alkali metal oxides from 3.5 to 15%, and at least one kind selected from the group made of Sn oxide and Ce oxide being included, a total content of Sn oxide and Ce oxide ranges from 0.05 to 2.00%, a glass transition temperature ≥625° C., a Young's modulus ≥83 GPa, a specific gravity ≤2.85, and an average linear expansion coefficient at 100 to 300° C.≥48×10−7 / ° C.

An optical glass having high-refractivity and low-dispersion properties and containing, by mol %, 0.1 to 40% of SiO2, 10 to 50% of B2O3, wherein the mass ratio of the content of SiO2 to the content of B2O3, SiO2 / B2O3, is 1 or less, 0.5 to 22% of ZnO, 5 to 50% of La2O3, and optionally other ingredients. The optical glass has a refractive index nd of 1.86 to 1.95 and an Abbe's number vd of (2.36−nd) / 0.014 or more but less than 38, and a glass transition temperature of equal to or greater than 640° C.

The invention provides optical glass for precision compression, a preformed unit for precision compression and an optical element, wherein the nd is between 1.65 and 1.75, vd is between 50 and 60 and the transformation temperature Tg is less than 540 DEG C. The optical glass comprises the following compositions by weight percentage: 0 to 15 percent of SiO2, 28 to 43 percent of B2O3, 21 to 35 percent of La2O3, 0 to 15 percent of Gd2O3, Y2O3 and Yb2O3, 3 to 13 percent of ZnO, 1 to 8 percent of Li2O, Na2O and K2O, 1 to 20 percent of MgO, CaO, SrO and BaO, 0 to 8 percent of ZrO2, 0 to 0.1 percent of Sb2O3, 0 to 0.5 percent of SnO2, and 0 to 3 percent of Ta2O5, WO3, Nb2O5 and TiO2. The optical glass prolongs the service life of a mould, realizes high-efficiency production, and simultaneously can also reduce the production cost of the optical element.

An optical glass that is an oxide glass having a very high refractive index in spite of its low-dispersion property, having excellent glass stability and having less susceptibility to coloring.

An optical glass which has an Abbe's number (νd) 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, 0.1 to 15% of ZnO, 2 to 20% of CaO, 0 to 5% of BaO, provided that the content of BaO is smaller than the content of ZnO, 0 to 5% of SrO, 0 to 5% of MgO, provided that the molar ratio of the total content of MgO, CaO, SrO and BaO to the total content of B2O3 and SiO2 [(MgO+CaO+SrO+BaO) / (B2O3+SiO2) is from 0.1 to 0.4, and 0 to 5% of ZrO2, and having a refractive index (nd) and an Abbe's number (νd) which satisfy the equation (1),νd≧308.5−150×nd (in which 50≦νd≦59)  (1).

The invention provides 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. An optical glass is an oxide glass and is characterized in that the optical glass comprises, by cationic %, 0 to 30% of Si<4>, 10 to 55% of B<3>, less than 5% of total of Li<>, Na<> and K<>, less than 5% of total of Mg<2>, Ca<2> and Sr<2>, 0 to 8% of Ba<2>, 0.1 to 15% of Zn<2>, 10 to 50% of La<3>, 0 to 20% of Gd<3>, 0 to 15% of Y<3>, 0 to 10% of Yb<3>, 0 to 20% of Zr<4>, 0.1 to 22% of Ti<4>, 0 to 20% of Nb<5>, 0 to 8% of Ta<5>, 0 to 5% of W<6>, 0 to 8% of Ge<4>, 0 to 10% of Bi<3>, and 0 to 10% of Ai<3>, the cationic ratio of the content of Si<4> to the content of B<3>, Si<4> / B<3>, 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 nud of 25 to 45.

Provided is a near-infrared light absorbing glass with a near-infrared light absorbing element and a near-infrared light absorbing filter. When the length of the near-infrared light absorbing glass is 1 mm, transmissivity is more than 80% at the wavelength of 400 nm, and more than 85% at the wavelength of 500 nm. The near-infrared light absorbing glass contains P5+, Al3+, Li+, R2+ and Cu2+ represented by positive ions, wherein R2+ represents Mg2+, Ca2+, Sr2+ and Ba2+. Meanwhile, the near-infrared light absorbing glass contains O2− and F− represented by negative ions. Water durability (DW) of the near-infrared light absorbing glass reaches Class 1 and acid durability (DA) reaches above Class 4. In this invention, fluorphosphate glass is used as the matrix glass and the components are designed specially, so that the melting temperature of glass can be effectively lowered and the chemical stability of the glass can be excellent.

An optical glass that is an oxide glass and comprises, by cationic %,20 to 40% of a total of Si4+ and B3+,15 to 40% of a total of Nb5+, Ti4+, W6+ and Zr4+,0.2 to 20% of a total of Zn2+, Ba2+, Sr2+ and Ca2+, and15 to 55% of a total of Li+, Na+ and K+,the cationic ratio of the content of B3+ to the total content of B3+ and Si4+ being 0.01-0.5,the cationic ratio of the content of Zr4+ to the total content of Nb5+, Ti4+, W6+ and Zr4+ being 0.05 or less,the molar ratio of the total content of Zn2+ and Ba2+ to the total content of Zn2+, Ba2+, Sr2+ and Ca2+ being 0.8-1,the optical glass having a refractive index nd of 1.815 or more and an Abbe's number νd of 29 or less.