| 摘要 |
A scale-like glass (10) having improved heat resistance and chemical resistance is formed from a glass base material satisfying, in mass%, 60‰¤SiO 2 ‰¤75, 5<Al 2 O 3 ‰¤15, 3‰¤CaO‰¤20, 6‰¤Na 2 O‰¤20 and 9‰¤(Li 2 O+Na 2 O+K 2 O)‰¤13. When 9‰¤(Li 2 O+Na 2 O+K 2 O)‰¤13 is satisfied in mass%, the CaO content and the Na 2 O content are preferably set within the ranges of 5‰¤CaO‰¤20 and 6‰¤Na 2 O‰¤13, respectively. When 13‰¤(Li 2 O+Na 2 O+K 2 O)‰¤20 is satisfied in mass%, the CaO content and the Na20 content are preferably set within the ranges of 3‰¤CaO‰¤15 and 9‰¤5Na 2 O‰¤2O, respectively. The working temperature of the glass base material is preferably 1180°C-1300°C. The temperature difference ”T obtained by taking the devitrification temperature of the glass base material from the working temperature of the glass base material is preferably 0°C-200°C. The glass transition temperature of the glass base material is preferably 550°C-700°C. The acid resistance index ”W of the glass base material is preferably 0.05-1.5 mass%. |
