Abstract: The glass or glass-ceramic has the following composition (in % by weight based on oxide content): SiO2, 25 to 50; B2O3, >5 to 16; Al2O3, 10 to 17; P2O5, 0 to 8; Li2O,5 to 15; Na2O, 0 to 10; K2O, 0 to 10; MgO, 10 to 30; CaO, 0 to 10; SrO, 0 to 8; ZnO, 0 to 8; TiO2, 0.1 to 10; ZrO2, 0 to 8; and at least one refining agent, in an amount as needed according to its purpose. The sum total amount of divalent metal oxides (RO) present is less or equal to than 45% by weight based on oxide content and the sum total amount of alkali metal oxides (R2O) present is less than or equal to 30% by weight based on oxide content. The glass or glass-ceramic material generally has elasticity modulus values (E)>90×103 N/mm2 and <125×103 N/mm2, specific elasticity modulus values (E/&rgr;)>30×105 N cm/g and <45×105 N cm/g and thermal expansion coefficient values (&agr;20/300)>7.0×10−6/K and <11.0×10−6/K.

Abstract: The lead-free bismuth-containing silicate glasses, which are particularly suitable for use as funnel glass or neck glass for cathode ray tubes and as soldering glass, have the following respective compositions (in % by weight, based on oxide): SiO2 40-60; Bi2O3, 10-30; ZrO2, 0-3; Al2O3, 0.5-5; MgO, 0-6; CaO, 0.5-5; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li2O, 0-10; Na2O, 1-10; K2O, 2-10; Cs2O, 0-3, sum of the alkali metal oxides, 5-20; CeO2, 0-8; WO3, 0.5-5; MoO3, 0-5 and Sb2O3, 0-0.6; and SiO2 30-50; Bi2O3, 20-40; ZrO2, 0-3; Al2O3, 0.5-5; MgO, 0-4; CaO, 0.5-4; SrO, 1-15; BaO, 0-15; sum of the alkaline earth metal oxides, 2-20; ZnO, 0-2; Li2O, 0-5; Na2O, 1-12; K2O, 2-15; Cs2O, 0-3, sum of the alkali metal oxides, 5-20; CeO2, 0-8; WO3, 0.5-5; MoO3, 0-5 and Sb2O3, 0-0.6.

Abstract: The lead-free optical light flint glass material has a refractive index nd between 1.54 and 1.61 and an Abbe number &ngr;d of between 38 and 45. It has a composition, based on oxide content, of SiO2 from 52 to 62% by weight, Al2O3 from 3 to 8% by weight, Na2O from 7 to 14% by weight, K2O from 8 to 14% by weight, TiO2 from 13 to 18% by weight, ZrO2 from 0 to 5% by weight, with at least one refining agent, if needed, in an amount suitable for the purposes of refining; and with the proviso that a sum total of Na2O and K2O present is greater than 18% by weight.