| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject glass having excellent chemical durability, low expansion and not generating deposition of a crystal in glass when molding even in molding by a Danner method, by constituting a specific composition and imparting prescribed physical properties thereto. SOLUTION: This glass is composed of 70.0-75.0wt.% SiO2 , 13.1-15.0wt.% B2 O3 , 5.0-6.5wt.% Al2 O3 , 0.1-1.0wt.% CaO, 5.5-7.5wt.% Na2 O, 0.5-2.5wt.% K2 O and 0.01-0.5wt.% of a clarifying agent (e.g.; Sb2 O3 ) and has (45-53)×10<-7> / deg.C linear expansion coefficient at 30-380 deg.C, >=0.30ml alkali elution amount according to the 12th improved Japanese pharmacopoeia, a glass vessel test method for injections, the first method of alkali elution test and a viscosity at a liquid phase temperature, logη>=5.2.
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