Patent ID: 6551952
Filing Date: 2003-04-22
Classification: C03C,Y10S

Abstract:
A lead-free optical glass material with a refractive index nd of between 1.54 and 1.61 and an Abbe number &ngr;d of between 38 and 45, said glass material consisting, based on oxide content, ofSiO2from 52 to 62% by weight,Al2O3from 3 to 8% by weight,Na2Ofrom 7 to 14% by weight,K2Ofrom 8 to 14% by weight,TiO2from 13 to 18% by weight,ZrO2from 0 to 5% by weight,and from 0.1 to 0.5% by weight of Sb2O3 as refining agent; and with the proviso that a sum total of said Na2O and said K2O present is greater than 18% by weight.