Jenaer Glaswerk Schott & Gen.

Schott Glaswerke

Deutsche Spezialglas Ag

Georg Gliemeroth

Volkmar Geiler

Lothar Meckel

Burkhard Speit

Karl Mennemann

Ludwig Ross

Hans-Georg Krolla

Marga Faulstich

Uwe Eichhorn

Danuta Grabowski

Werner Behr

Hans-Jurgen Hoffmann

Peter Heinemann

Eva Holzel

Klaus-Peter Hanke

Eva G Hoelzel

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

A phototropic glass with the optical characteristics of n.sub.d greater than to or equal to 1.59 and v.sub.d greater than or equal to 44, and with a density less than or equal to 3.0 g/cm.sup.-3 is provided having a composition comprising:

Phototropic glass with a refractive index greater than or equal to 1.59,

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

A colorless, cerium-and phosphorous-containing barium silicate glass, with a density of &gt;3.3 g/cm.sup.2, a radiation length &lt;43.5 mm, with strong fluorescence at 415-430 nm and with good scintillation properties, consisting essentially of (in percent by weight):

Scintillation glass

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):

These objects have been attained by providing highly absorbent lead containing alkali metal silicate glasses for cathode ray tube image screens, having a linear absorption coefficient .mu. of &gt;30 cm.sup.-1 (0.6 .ANG.) and with a high resistance to discoloration by X-ray and electron radiation, comprises, in weight percent:

High absorbance Pb-containing glass for cathode ray tube picture screen

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

A phototropic multilayered glass sheet incorporating at least two interfacially laminated layers, one layer consisting of a nonphototropic carrier glass, and at least one other layer consisting of a phototropic glass. In manufacture, at least one of the glass streams is characterized by having a viscosity of less than 10.sup.7.6 d PAS at the location where the streams are brought together.

Flashed 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:

Optical and ophthalmic glass with refractive indices nd&gt;1.58, Abbe

An improved optical glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.38, and a density of .ltoreq.3.25 g/cm.sup.3, represents a further development of another optical glass recently provided by the same inventors. The new glass has improved suitability for continuous-tank manufacture and increased acidproofness and differs from the other glass in its content of 0.5-4.0% by weight of P.sub.2 O.sub.5 ; its sum total of SiO.sub.2 +B.sub.2 O.sub.3 +Al.sub.2 O.sub.3 +P.sub.2 O.sub.5 being 38.5-41.5% by weight; and its sum total of MgO+CaO being 13-17.5% by weight. The full glass composition, e.g. is in % by weight:

Acidproof, hydrolysis-resistant optical and ophathalmic glass of low

An optical and ophthalmic glass having an index of refraction of .gtoreq.1.69, an Abbe number of .gtoreq.37, and a density of .ltoreq.3.30 g/cm.sup.3, consists essentially of (in % by weight):

Acidproof, hydrolysis-resistant optical and ophthalmic glass of low

An optical fiber comprising a light-conducting core and a borosilicate glass optical insulation cladding thereon is stabilized against the effects of nuclear radiation by incorporating in the core and the cladding an amount of Sb.sub.2 O.sub.3 effective to harden the fiber against nuclear radiation. Amounts of 0.002-6 wt. % Sb.sub.2 O.sub.3 are generally useful.

Optical fibers for communication transmission having high stability to

Optical glasses having high refractive indexes and low specific gravities are provided for use as both distant and near vision spectacle lenses. The glasses consist essentially of low molecular weight cationic oxides, alkali metal oxides and divalent oxides to promote the crystallization stability of the glass. They have good chemical resistance, chemical hardenability and a thermal expansion coefficient between 93 and 99.times.10.sup.-7 /.degree. C. in the range of 20.degree.-300.degree. C. Optical lenses can be continuously produced due to the high crystallization stability of the glasses and the resultant spectacle lenses have high dioptric values even with thinner edge or center thicknesses.

High refractive index glasses of limited specific gravity for distance

A glass having a high refractive index, preferably &gt;1.77, and a low specific gravity, preferable .ltoreq.3.8, is provided for utilization as spectacle lenses. The glass consists essentially of 80 mol percent or more of light cationic oxides with the remainder being cationic oxides having a greater molecular weight. It has a high crystallization stability in a viscosity range &gt;200 poises and an expansion coefficient .alpha..times.10.sup.7 between 20.degree.-300.degree. C. of .ltoreq.100. Sufficiently light in weight to be well-suited for use as spectacle lenses, the glass can be continuously produced, as it has no pronounced tendency toward crystallization. The resulting corrective optical lenses have relatively high dioptric values, even with small center and edge thicknesses.

Growing community of inventors

Mainz-Finthen, Germany

Georg Gliemeroth