Schott Glaswerke

Jenaer Glaswerk Schott & Gen.

Other

Volkmar Geiler

Georg Gliemeroth

Ludwig Ross

Karl Mennemann

Burkhard Speit

Danuta Grabowski

Marc Clement

Hans-Georg Krolla

Lothar Meckel

Marga Faulstich

Guster Schumacher

Burkhart Speit

Mario Dalle Donne

Uwe Eichhorn

Danuta Grabowski Geb Marszalek

Hans-Jurgen Hoffmann

Eva Holzel

Substantially spherical particles of lithium silicates with improved mechanical properties and improved surface quality are provided, which are particularly suited for use as breeding material for tritium. The particles are characterised in that they contain additions of tellurium and/or tellurium compounds.

Substantially spherical particles of lithium silicates with improved

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):

Optical glass of negative anomalous partial dispersion in the blue region

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 &gt;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 &lt;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.

Optical glass with negative anomalous partial dispersion

An optical glass, n.sub.d .gtoreq.1.60 and v.sub.d .gtoreq.58, having a high chemical stability as well as resistance to phase separation and crystallization, comprises in percent by weight:

Optical glass with refractive index 1.60, an abbe number 58, with high

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.

Highly refractive optical glass with refractive indices &gt;1.83 and Abbe

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.

High PbO-content glasses in the system SiO.sub.2 --PbO--M.sub.2 O with

An optical and ophthalmic glass with high refractive index, high Abbe number and low density, which is distinguished by good chemical stability, good crystallization behavior and capability of chemical hardening, comprises (in % by weight):

Optical and ophthalmic glass with refractive indices greater than or

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%.

Optical glass with refractive indices&gt;1.90, Abbe numbers&gt;25 and high

An optical and ophthalmic glass with high refractive index, high Abbe number and low density, which is distinguished by good chemical stability, good crystallization behavior and capability for chemical hardening, comprises (in % by weight):

An optical glass with the familiar optical position of n.sub.d &gt;1.70 and v.sub.d &gt;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.

Optical light weight glass with a refractive index of &gt;1.70, an Abbe

A spectacle glass which is colorless in the visible spectrum range, not transmissive in the ultraviolet spectrum range below 350 nm, has a refractive index n.sub.d higher than 1.56 and an Abbe number of more than 45, and which has an extremely low density, has the following composition (in % by weight):

Spectacle glass with increased refractive index

A new phototropic glass in which the phototropic properties arise from precipitations of silver halide and which in the unirradiated condition is slightly tinted or completely colorless while showing a brown color in the light-exposed condition, comprises, in known phototropic glass compositions, an additional content of at least 0.001 wt % of TeO.sub.2 and/or Yb.sub.2 O.sub.3.

Phototropic glass with a brown tint in the irradiated state

CdO- and ThO-free, highly refractive optical glass having a refractive index of 1.85-2.05 and an Abbe index of 25-43, characterized by the following composition (in percent by weight):

CdO-ThO.sub.2 -Free, highly refractive optical glass

A borosilicate glass composition suitable for use as an eyeglass lens, characterized by having a refractive index nd.gtoreq.1.58, an Abbe number vd.gtoreq.45, a density .rho..ltoreq.2.75 g/cm.sup.3, and an excellent aptitude for chemical hardening, consisting essentially of the following composition, in weight percent:

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Mainz-Finthen, Germany

Volkmar Geiler