Abstract: A glass for substrate, which consists, as represented by mass percentage, essentially of: SiO2 40 to 59%, Al2O3 ?5 to 20%, B2O3 ?0 to 8%, MgO ?0 to 10%, CaO ?0 to 12%, SrO ?2 to 20%, BaO ?0 to 2%, ZnO ?0 to 4%, Li2O ?0 to 2%, Na2O ?0 to 10%, K2O ?0 to 12%, TiO2 ?0 to 10%, and ZrO2 ?0 to 5%, wherein MgO+CaO+SrO+BaO is at least 15%.

Abstract: A glass substrate for a display with a thickness of from 0.3 to 6 mm, which has an average WCA (filtered center line waviness: JIS B0651) of from 0.03 to 0.5 &mgr;m measured with a contact-type surface roughness measuring instrument using a phase compensation 2RC zone filter with a cutoff value of 0.8 to 25 mm over a measuring length of 200 mm.

Abstract: An alkali-free glass consisting essentially of: SiO2 64 to 76 mol %,  Al2O3 5 to 14 mol %, B2O3 5 to 16 mol %, MgO 1 to 16.5 mol %, CaO 0 to 14 mol %, SrO 0 to 6 mol %, and BaO 0 to 2 mol %.

Abstract: A glass substrate for a display, which has a strain point of at least 550° C., an average linear expansion coefficient of from 65×10−7 to 100×10−7/°C. within a range of from 50 to 350° C. and a ratio KIC/d of at least 280 Pa·kg·m7/2 where KIC is the fracture toughness and d is the density.

Abstract: A glass for a data storage medium substrate, which consists essentially of the following components as represented by mol %: SiO2 60 to 72, Al2O3  2 to 9 MgO  3 to 9, CaO  2 to 10, SrO  0 to 15, ZnO  0 to 4, TiO2  0 to 8, ZrO2  0 to 4, Li2O  1 to 12, Na2O  0 to 8, K2O  0 to 5, Y2O3  0 to 5, La2O3  0 to 5, and Li2O + Na2O + K2O  4 to 15, and which has a Young's modulus of at least 85 GPa.

Abstract: A glass substrate for a display with a thickness of from 0.3 to 6 mm, which has an average WCA (filtered center line waviness: JIS B0651) of from 0.03 to 0.5 &mgr;m measured with a contact-type surface roughness measuring instrument using a phase compensation 2RC zone filter with a cutoff value of 0.8 to 25 mm over a measuring length of 200 mm.

Abstract: A glass for substrate, which consists, as represented by mass percentage, essentially of: 1 SiO2 40 to 59%, Al2O3  5 to 20%, B2O3  0 to 8%, MgO  0 to 10%, CaO  0 to 12%, SrO  2 to 20%, BaO  0 to 2%, ZnO  0 to 4%, Li2O  0 to 2%, Na2O  0 to 10%, K2O  0 to 12%, TiO2  0 to 10%, and ZrO2  0 to 5%,

Abstract: A hollow glass microsphere having an average particle size of at most 15 &mgr;m based on volume, a maximum particle size of at most 30 &mgr;m and an average particle density of from 0.1 to 1.5 g/cm3, which has a glass composition consisting essentially of the following components by mass %: 1 SiO2 50.0-90.0%,   Al2O3 10.0-50.0%,   B2O3 0-12.0%, Na2O + K2O + Li2O 0-1.0%,  CaO 0-10.0%, MgO 0-10.0%, BaO + SrO 0-30.0%.

Abstract: A glass for a substrate, having an average thermal expansion coefficient in the range of from 60×10−7 to 75×10−7/° C. at 50 to 350° C., which consists essentially of the following composition expressed by wt %: wt % SiO2 more than 62 to 74, Al2O3  1 to 15, MgO  0 to 9, CaO  0 to 14, Na2O  0 to 12, K2O  0 to 13, SiO2 + Al2O3 72 to 82, MgO + CaO  5 to 24, Na2O + K2O  1 to 15, MgO + CaO + Na2O + K2O 18 to 28.

Abstract: A glass for a substrate consisting essentially of: SiO2 45 to 65 wt %, Al2O3 6 to 20 wt %, B2O3 0.5 to 6 wt %, MgO 2 to 5 wt %, CaO 1 to 10 wt %, SrO 0 to 6.5 wt %, BaO 0 to 2 wt %, MgO + CaO + SrO + BaO 10 to 17 wt %, ZrO2 0 to 7 wt %, and Na2O + K2O 7 to 15 wt %.

Abstract: A plate glass containing B2O3, having a total content of Li2O, Na2O and K2O of from 0 to 13 mol %, a content of BaO of from 0 to 0.8 mol % and a content of SiO2 of from 50 to 75 mol %, and having an average linear thermal expansion coefficient of from 75×10−7 to 120×10−7/° C. in a range of from 50 to 350° C., a strain point of at least 550° C., a density of at most 2.65 g/cm3 at 20° C. and an oxygen atom density of from 7.2×10−2 to 9.0×10−2 mol/cm3 at 20° C.

Abstract: An alkali-free glass consisting essentially of, by wt %, from 58.4 to 66.0% of SiO2, from 15.3 to 22.0% of Al2O3, from 5.0 to 12.0% of B2O3, from 0 to 8.0% of MgO, from 0 to 9.0% of CaO, from 3.0 to 12.5% of SrO, from 0 to less than 2.0% of BaO, and from 9.0 to 18.0% of MgO+CaO+SrO+BaO and having a strain point of at least 640° C.

Abstract: A glass composition for a substrate consisting essentially of from 56 to 72 wt % of SiO.sub.2, from 1 to less than 14 wt % of Al.sub.2 O.sub.3, from 0 to 9 wt % of MgO, from 0.5 to 11 wt % of CaO, from 0 to 4 wt % of SrO, from 0 to 3 wt % of BaO, from 6 to less than 14 wt % of MgO+CaO+SrO+BaO, from 0 to 9 wt % of Na.sub.2 O, from 6 to 20 wt % of K.sub.2 O, and from 6 to 20 wt % of Na.sub.2 O+K.sub.2 O.

Abstract: An alkali-free glass consisting essentially of from 60 to 74 mol % of SiO.sub.2, from 10 to 16 mol % of Al.sub.2 O.sub.3, from 10 to 12 mol % of B.sub.2 O.sub.3, the molar ratio of Al.sub.2 O.sub.3 /B.sub.2 O.sub.3 being from 1.0 to 1.5, from 0 to 5 mol % of MgO, from 0 to 5 mol % of CaO, from 0 to 12 mol % of SrO, from 0 to 12 mol % of BaO, and from 6 to 12 mol % of SrO+BaO, which contains substantially no alkali metal oxide and has a strain point exceeding 650.degree. C. and an average thermal expansion coefficient of at most 40.times.10.sup.-7 /.degree.C. within a range of from 50.degree. to 300.degree. C., and of which the weight loss per unit area after immersion at 25.degree. C. for 20 minutes in a liquid prepared by mixing a 40 wt % ammonium fluoride aqueous solution and a 50 wt % hydrofluoric acid aqueous solution in a volume ratio of 9:1, is less than 0.60 mg/cm.sup.2, the weight loss per unit area after immersion at 95.degree. C. for 20 hours in 0.1N HCl, is less than 0.20 mg/cm.sup.

Abstract: A glass composition for a substrate consisting essentially of from 59 to 72 wt % of SiO.sub.2, from 1 to 15 wt % of Al.sub.2 O.sub.3, from 0.5 to 9 wt % of MgO, from 0.5 to 11 wt % of CaO, from 0 to 6 wt % of SrO, from 0 to 5 wt % of BaO, from 4 to 19 wt % of MgO+CaO+SrO+BaO, from 0 to 9 wt % of Na.sub.2 O , from 4 to 21 wt % of K.sub.2 O, from 10 to 22 wt % of Na.sub.2 O+K.sub.2 O, and from 0.5 to 10.5 wt % of ZrO.sub.2, wherein the difference between the SiO.sub.2 content and the Al.sub.2 O.sub.3 content is from 50 to 71 wt %, and the specific gravity of the composition is less than 2.6.

Abstract: An alkali-free glass consisting essentially of from 60 to 73 mol % of SiO.sub.2, from 5 to 16 mol % of Al.sub.2 O.sub.3, from 5 to 12 mol % of B.sub.2 O.sub.3, from 0 to 6 mol % of MgO, from 0 to 9 mol % of CaO, from 1 to 9 mol % of SrO, from 0 to less than 1 mol % of BaO, and from 7 to 18 mol % of MgO+CaO+SrO+BaO and having a strain point of at least 640.degree. C.

Abstract: Abrasion resistant glass, which consists essentially of the following components:______________________________________ SiO.sub.2 75.5 to 85.5 (wt %), RO 1 to 8 (wt %), R'.sub.2 O 10 to 23.5 (wt %), RO + R'.sub.2 O 11 to 24.5 (wt %), Al.sub.2 O.sub.3 0 to 5 (wt %), ______________________________________ RO/R'.sub.2 O (weight ratio) at most 0.5,provided that R is at least one member selected from Mg and Ca, and R' is at least one member selected from Li, Na and K, and of which the density measured at room temperature is at most 2.41 g/cc.

Abstract: Abrasion resistant glass, which consists essentially of the following components:______________________________________ SiO.sub.2 74 to 85.5 (wt %), B.sub.2 O.sub.3 0.5 to 5 (wt %), SiO.sub.2 + B.sub.2 O.sub.3 76 to 88 (wt %), RO 1 to 9 (wt %), R'.sub.2 O 10 to 23 (wt %), RO + R'.sub.2 O 11 to 24 (wt %), Al.sub.2 O.sub.3 0 to 5 (wt %), RO/R'.sub.2 O (weight ratio) at most 0.6, ______________________________________provided that R is at least one member selected from Mg and Ca, and R' is at least one member selected from Li, Na and K, and of which the density measured at room temperature is at most 2.43 g/cc.

Abstract: A glass composition for a substrate consisting essentially of from 52 to 62 wt % of SiO.sub.2, from 5 to 12 wt % of Al.sub.2 O.sub.3, from 0 to 4 wt % of MgO, from 3 to 5.5 wt % of CaO, from 6 to 9 wt % of SrO, from 0 to 13 wt % of BaO, from 17 to 27 wt % of MgO+CaO+SrO+BaO, from 7 to 14 wt % of Li.sub.2 O+Na.sub.2 O+K.sub.2 O, from 0.2 to 6 wt % of ZrO.sub.2, and from 0 to 0.6 wt % of SO.sub.3.

Abstract: An alkali free glass consisting essentially of from 50 to 60 wt % of SiO.sub.2, from 8 to 16 wt % of Al.sub.2 O.sub.3, from 4 to 10 wt % of B.sub.2 O.sub.3, from 1.5 to 5 wt % of MgO, from 0 to 7 wt % of CaO, from 0 to 10 wt % of SrO, from 10 to 20 wt % of BaO and from 0 to 3 wt % of ZnO and essentially free from alkali metal oxides.