PROBLEM TO BE SOLVED: To provide a glass tube for a medical container which is a borosilicate glass containing no BaO and can maintain excellent chemical durability or hydrolysis resistance even after various heat treatment in a processing process.SOLUTION: A glass tube for a medical container is formed of borosilicate glass containing, by mass%, SiO2 of 65 to 80%, Al2O3 of 5 to 15%, B2O3 of 2 to 12%, Na2O of 3 to 10%, K2O of 0 to 5%, Li2O of 0 to 5%, MgO of 0 to 5%, CaO of 0 to 5%, SrO of 0 to 5% with a value of Al2O3/(Na2O+K2O+Li2O+MgO+CaO+SrO+B2O3) of 0.35 to 0.60 by mass ratio, practically has no BaO, and has a value of (atomic concentration of Na)/(atomic concentration of Na+atomic concentration of Si) in a region by 200 nm depth from an inner surface of the glass tube of 0.01 to less than 0.5.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2017,JPO&INPIT【課題】BaOを含有しないホウケイ酸ガラスであって、加工工程での種々の熱処理後も優れた化学的耐久性や加水分解抵抗性を維持できる医薬容器用ガラス管を提供することである。【解決手段】質量%でSiO2 65~80%、Al2O3 5~15%、B2O3 2~12%、Na2O 3~10%、K2O 0~5%、Li2O 0~5%、MgO 0~5%、CaO 0~5%、SrO 0~5%含有し、質量比でAl2O3/(Na2O+K2O+Li2O+MgO+CaO+SrO+B2O3)の値が、0.35~0.60であり、BaOを実質的に含まないホウケイ酸ガラスからなるとともに、ガラス管の内表面から200nmの深さまでの領域における(Naの原子濃度)/(Naの原子濃度+Siの原子濃度)の値が0.01~0.5未満であることを特徴とする。【選択図】図2
