| 摘要 |
The lead-free optical light flint glass material has a refractive index nd between 1.54 and 1.61 and an Abbe number nud 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.
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