摘要 |
The invention discloses boron-free neutral glasses having the composition (in % by weight, based on oxide) 65-72 SiO2, 11-17 Al2O3, 0.1-8 Na2O, 3-8 MgO, 4-12 CaO and 0-10 ZnO, a ratio CaO/MgO of 1.4 to 1.6, and having a hydrolytic resistance in accordance with DIN ISO 719 in class 1 and an acid resistance in accordance with DIN 12116 and an alkali resistance in accordance with DIN ISO 695 at least in class 2.
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