Abstract: Zinc-containing optical glass materials with a refractive index nd between 1.52 and 1.66, an Abbe number ?d of between 35 and 54 and a composition (in % by weight based on oxide) of: SiO2 38–58, ZnO 0.3–42, PbO 0–<30, ZnO+PbO 20–55, Li2O 0–<3, Na2O 0–14, K2O 0–12, Li2O+Na2O+K2O ?2, F 0–3, MgO 0–6, CaO 0–<5, SrO 0–6, BaO 0–<0.9, B2O3 0–<1, Al2O3 0–<1.5 and ZrO2 0–<2 and, if appropriate, refining agents in the customary amounts.

Abstract: Zinc-containing optical glass materials with a refractive index nd between 1.52 and 1.66, an Abbe number ?d of between 35 and 54 and a composition (in % by weight based on oxide) of: SiO2 38-58, ZnO 0.3-42, PbO 0-<30, ZnO+PbO 20-55, Li2O 0-<3, Na2O 0-14, K2O 0-12, Li2O+Na2O+K2O ?2, F 0-3, MgO 0-6, CaO 0-<5, SrO 0-6, BaO 0-<0.9, B2O3 0-<1, Al2O3 0-<1.5 and ZrO2 0-<2 and, if appropriate, refining agents in the customary amounts.

Abstract: Zinc-containing optical glass materials with a refractive index nd between 1.52 and 1.66, an Abbe number vd of between 35 and 54 and a composition (in % by weight based on oxide) of: SiO2 38-58, ZnO 0.3-42, PbO 0-<30, ZnO+PbO 20-55, Li2O 0-<3, Na2O 0-14, K2O 0-12, Li2O+Na2O+K2O≧2, F 0-3, MgO 0-6, CaO 0-<5, SrO 0-6, BaO 0-<0.9, B2O3 0-<1, Al2O3 0-<1.5 and ZrO2 0-<2 and, if appropriate, refining agents in the customary amounts.

Abstract: Zinc-containing optical glass materials with a refractive index nd between 1.52 and 1.66, an Abbe number &ngr;d of between 35 54 and a composition (in % by weight based on oxide) of: SiO2 38-58, ZnO 0.3-42, PbO 0-<30, ZnO+PbO 20-55, Li2O 0-<3, Na2O 0-14, K2O 0-12, Li2O+Na2O+K2O≧2, F 0-3, MgO 0-6, CaO 0-<5, SrO 0-6, BaO 0-<0.9, B2O3 0-<1, Al2O3 0-<1.5 and ZrO2 0-<2 and, if appropriate, refining agents in the customary amounts.

Abstract: The invention relates to a copper(II) oxide-containing aluminophosphate glass having good chemical resistance, very good devitrification stability, high transmission at wavelengths in the range from 350 to 550 nm and a refractive index n.sub.d of from 1.52 to 1.54. The glass has the following composition (in % by weight, based on oxide): Al.sub.2 O.sub.3 4-9; P.sub.2 O.sub.5 67-75; BaO 0.5-6; CaO 0.1-1; MgO 0-4; SrO 0-1; ZnO 0.2-1; .SIGMA.BaO+CaO+MgO+SrO+ZnO 3.5-7; Na.sub.2 O 1.5-5; K.sub.2 O 2.5-3.5; Li.sub.2 O 0.5-5; .SIGMA.Na.sub.2 O+K.sub.2 O+Li.sub.2 O 5-13; SiO.sub.2 0-1; B.sub.2 O.sub.3 1-2.5; AS.sub.2 O.sub.3 0.1-0.5; Cl.sup.- 0-0.3; F.sup.- O-1.3; CeO.sub.2 0.2-0.4; CuO 1-6; with K.sub.G =.SIGMA.Al.sub.2 O.sub.3 +SiO.sub.2 +CeO.sub.2 /.SIGMA.P.sub.2 O.sub.5 +B.sub.2 O.sub.3 0.06-0.125.

Abstract: Disclosed is a barium-free glass of good x-ray absorption, which has a composition (in wt.-% on the oxide basis) of SiO.sub.2 50-75; ZrO.sub.2 5-30; Li.sub.2 O 0-5; Na.sub.2 O 0-25; K.sub.2 O 0-25; .SIGMA. alkali oxides 0-25. Preferred is a dental glass of the composition of SiO.sub.2 55-70; ZrO.sub.2 10-25; Li.sub.2 O 0-15; Na.sub.2 O 10-25; K.sub.2 O 0-15; .SIGMA. alkaloids 15-25. The glass can furthermore contain also up to 3 wt.-% of fluorine, up to 5 wt.-% of MgO, up to 5 wt.-% of TiO.sub.2, and in each case up to 10 wt.-% of the oxides Al.sub.2 O.sub.3, GeO.sub.2, P.sub.2 O.sub.5, La.sub.2 O.sub.3, Y.sub.2 O.sub.3, Ta.sub.2 O.sub.3, Gd.sub.2 O.sub.3, ZnO and Nb.sub.2 O.sub.5. The glass finds its use in powder form with an average particle size of .ltoreq.10 .mu.m as filler for dental composites for filling teeth.

Abstract: A chemically resistant glass which can be produced at relatively low melting temperatures and has anomalous negative partial dispersion P.sub.g,F, a refractive index n.sub.d of from 1.73 to 1.83 and an Abbe coefficient v.sub.d of from 31 to 38 preferably contains (in % by weight, based on oxides):______________________________________ 0-4 SiO.sub.2 + GeO.sub.2 0-2 GeO.sub.2 0-10 MgO 26-33 B.sub.2 O.sub.3 0-1 Li.sub.2 O 0-16 CaO 19-50 PbO 0-1 Na.sub.2 O 0-16 BaO 1-6 ZrO.sub.2 0-1 K.sub.2 O 0-16 SrO 4-16 Ta.sub.2 O.sub.5 0-2 .SIGMA. alkaline earth 0-6 Al.sub.2 O.sub.3 metal oxides 0-16 ZnO 0-4 TiO.sub.2 1.5-20 .SIGMA. alkaline earth metal oxides + ZnO 0-1 WO.sub.3 0-11 La.sub.2 O.sub.3 0-7 Nb.sub.2 O.sub.5 0-5.5 Y.sub.2 O.sub.3 0-5.5 Gd.sub.2 O.sub.3 4-11 .SIGMA. La.sub.2 O.sub.3 + Y.sub.2 O.sub.3 + Gd.sub.2 O.sub.3 ______________________________________with the proviso that the .SIGMA.(SiO.sub.2 +GeO.sub.2 +B.sub.2 O.sub.3)/.SIGMA.(ta.sub.2 O.sub.5 +ZrO.sub.2 +HfO.sub.2) ratio is less than 5 and the PbO/.

Abstract: Silicate glasses are provided which when exposed to a silver ion exchange surface treatment are writable with electron beams. These glasses contain OD agents and do not require elements having 1-4 d-electrons in the atomic state.

Abstract: A glass having a negative anomalous partial dispersion .DELTA.P.sub.g,F, an index of refraction of n.sub.d .gtoreq.1.67 and an Abbe number of .nu..sub.d >36 has the following composition, in % by weight, 3-11 of SiO.sub.2, 0-3 of GeO.sub.2, .SIGMA. SiO.sub.2 +GeO.sub.2, 4.5-11; B.sub.2 O.sub.3, 29-35; 5-13 of Al.sub.2 O.sub.3 ; 1-3 of ZrO.sub.2 ; 0.2-3 of TiO.sub.2 ; 0.2-1.5 of Ta.sub.2 O.sub.5 ; 30-45 of PbO; 0-3 each of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Rb.sub.2 O, Cs.sub.2 O, .SIGMA. alkali metal oxide 0-3; 0-3.5 each of MgO, CaO, BaO, SrO, .SIGMA. alkaline-earth oxide 0-6, if .SIGMA. SiO.sub.2 and GeO.sub.2 .gtoreq.9; .SIGMA. alkaline-earth oxide 0-3.5, if .SIGMA. SiO.sub.2 and GeO.sub.2 <9; 0-14 of ZnO, 0-3 of La.sub.2 O.sub.3 ; 0-7 of Nb.sub.2 O.sub.3 ; 0-1 of Sb.sub.2 O.sub.3 ; 0-0.3 of As.sub.2 O.sub.3 ; 0-1.5 of WO.sub.3 ; 0-1 of F. This glass is inexpensive and can be produced in high quality, and has a high crystalization stability and good transmission values.

Abstract: A new, CdO-and ThO.sub.2 -free optical glass with refractive indices of 1.73-1.78 and Abbe numbers of 30-34 and with particularly good devitrification stability comprises (in weight %):______________________________________ SiO.sub.2 12-20, B.sub.2 O.sub.3 10-18, PbO 50-60 Al.sub.2 O.sub.3 2-7, ZnO 0-4, ZrO.sub.2 0.5-3 La.sub.2 O.sub.3 2-10, Cs.sub.2 O 0-5, M.sub.2 O 0-1 (M.sub.2 O.dbd. Na.sub.2 O, K.sub.2 O, Li.sub.2 O) TiO.sub.2 0-5 with the SiO.sub.2 /B.sub.2 O.sub.3 -ratio being about 1.0 to ______________________________________ 1.5.

Abstract: A highly refractive optical glass (n.sub.d .gtoreq.1.83) with high dispersion (v.sub.d .ltoreq.25) and very good chemical stability at relatively low density (.delta..ltoreq.3.5 g/cm.sup.3) consists of (in weight percent) SiO.sub.2 19-25, Na.sub.2 O 7-10, K.sub.2 O 4-7, Cs.sub.2 O 0-12, Cao 0.5-2.0, BaO 9-15, TiO.sub.2 25-30, ZrO.sub.2 0-6, Nb.sub.2 O.sub.5 16-20, WO.sub.3 0-3, with Nb.sub.2 O.sub.5 :TiO.sub.2 =0.6-0.71.

Abstract: High PbO-content glass in the optical range of flint and heavy flint glasses from the system SiO.sub.2 --PbO--M.sub.2 O wherein M.sub.2 O=alkali metal oxides, said glass having a minimum PbO content of 30 wt. % and a minimum M.sub.2 O content of 0.5 wt. %, are provided with enhanced chemical stability without loss of the desired optical position by replacing a portion of the SiO.sub.2 and PbO such that the glass contains 1.5-6 wt. % (TiO.sub.2 +ZrO.sub.2) and the ratio of TiO.sub.2 :ZrO.sub.2 is about 0.3-2.0.

Abstract: Optical glass compositions having refractive indexes of 1.60-1.69 and Abbe numbers higher than 54 as well as with a density of less than 3.4 g/cm.sup.3, and which are distinguished in that they have good chemical stability, comprising (in percent by weight): 5-30 percent SiO.sub.2 ; 20-55 percent B.sub.2 O.sub.3 ; 13-40 percent CaO; 3-25 percent La.sub.2 O.sub.3 ; and optionally one or more of the following: up to 7 percent ZrO.sub.2, up to 2 percent TiO.sub.2, up to 9 percent Al.sub.2 O.sub.3, up to 11 percent MgO, up to 10 percent ZnO, up to 10 percent SrO, and up to 12 percent BaO.

Abstract: Optical glass with refractive indicies.gtoreq.1.90, Abbe numbers.gtoreq.25 consisting essentially of, in weight percent; 0-10 SiO.sub.2, 2-20 B.sub.2 O.sub.3, 0-2 Al.sub.2 O.sub.3, the sum of SiO.sub.2, B.sub.2 O.sub.3, and Al.sub.2 O.sub.3 being 7.5-25, 1-16 TiO.sub.2, 0-10 ZrO.sub.2, 35-55 La.sub.2 O.sub.3, 0.5-10 Y.sub.2 O.sub.5, 0.5-15 Nb.sub.2 O.sub.5, 0-10 Gd.sub.2 O.sub.3, 0-15 Ta.sub.2 O.sub.5, 0-3 P.sub.2 O.sub.5 wherein the ratio of SiO.sub.2 to B.sub.2 O.sub.3 is between 0.1 and 1.6, and the sum of Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5 is from 9 to 20%.

Abstract: An optical glass with the familiar optical position of n.sub.d >1.70 and v.sub.d >22, which differs from the familiar optical glasses of the optical position due to its lower density and good chemical stability, and is composed of (in percent by weight): SiO.sub.2 25-42, TiO.sub.2 15-35, B.sub.2 O.sub.3 0.5-7, BaO 3-13, CaO 1-3, Nb.sub.2 O.sub.5 1-20, GeO.sub.2 0-2, Al.sub.2 O.sub.3 0-4, Na.sub.2 O 7.5-15, Li.sub.2 O 0-9, K.sub.2 O 2-10, SrO 0-6, ZnO 0-5, ZrO.sub.2 0-3, and WO.sub.3 0-3.

Abstract: Highly refractive, ThO.sub.2 -free optical glasses having refractive indices of 1.86-1.94 and Abbe-index numbers greater than or equal to 30, comprise:______________________________________ B.sub.2 O.sub.3 17-24 SiO.sub.2 0.5-6 B.sub.2 O.sub.3 + SiO.sub.2 19-27 La.sub.2 O.sub.3 40.1-51 ZrO.sub.2 5-9 Nb.sub.2 O.sub.5 0.5-25 Ta.sub.2 O.sub.5 0-27 Nb.sub.2 O.sub.5 + Ta.sub.2 O.sub.5 14-27 TiO.sub.2 0-8 PbO 0-12 ZnO 0-4 Al.sub.2 O.sub.