| 摘要 |
<p>Glass composition comprises (by wt.) 70-74 pref. 71-73% SiO2, 9-13 pref. 10-12% B2O3, 5-8 pref. 6-7% Al2O3 5-8 pref. 6-7% Na2O, 0-4 pref. 1-3% K2O, 0-3 pref. 0.2-2% CaO and 0-1 pref. 0.1-0.3% MgO, the glass has an annealing point of about 550-585 deg.C, a softening point of about 783-799 deg.C, a liquidus of about 1730-1760 deg.F and a log n at the liquidus of about 5.0-5.5 - The glass is a barium free type I, class B laboratory glass which meets the requirements of ASTME 438-80a, can be melted and fabricated economically, and is useful as laboratory ampuls or vials, the glass has a low linear coefficient of expansion between 0 and 300 deg.C of about 48 x 10 power -7 -56 x 10 power -7 cm/cm/deg.C, a chemical durability measured by a maximum titration equivalent of 0.02 N H2SO4/10g of glass. GBAB- GB2136413 B A barium-free Type I, Class B glass according to the standard specification set forth in ASTM E 438 - 80a having a linear coefficient of expansion (0 to 300 deg.C, cm/cm - deg.C x 10 power (-7)) of about 48 to 56 and having a chemical durability, maximum titration equivalent of: 0.02N H2SO4/10g of glass of 1.0 ml, the composition comprising the following ingredients in approximate percent by weight: SiO2 70-74%, B2O3 9.13%, Al2O3 5-8%, Na2O 5-8%, K2O 0.4%, CaO 0.3%, MgO 0.1% the glass composition having an annealing point of about 550 deg.C to 585 deg.C, a liquidus of about 1730 deg.F to 1760 deg.F (about 943 to 960 deg.C) and a Log n at the liquidus about 5.0 to 5.5.</p> |
