Patent ID: 6709998
Filing Date: 2004-03-23
Classification: C03C

Abstract:
A lead-free optical glass having a refractive index nd of 1.65 to 1.80 and an Abbe number &ngr;d of 21 to 33 comprising in % by weight, based on oxideSiO227-40B2O3â€ƒâ€‰0-<0.5Al2O30-6Na2Oâ€‚7-18K2Oâ€‚1-10BaOâ€‚1-10SrO0-3CaO0.5-5â€‚â€‰MgO0-3with BaO + SrO + CaO + MgO<15TiO221-37ZrO20-7Nb2O5â€‚5-17WO30.1-7â€‚â€‰and optionally one or more refining agents.