US Patent 9012343 Glass for chemical strengthening

There is provided a glass for chemical strengthening having a black color tone and excelling in characteristics preferred for the purposes of housing or decoration of an electronic device, that is, bubble quality, strength, and light transmittance characteristics. A glass for chemical strengthening contains, in mole percentage based on following oxides, 55% to 80% of SiO2, 3% to 16% of Al2O3, 0% to 12% of B2O3, 5% to 16% of Na2O, 0% to 4% of K2O, 0% to 15% of MgO, 0% to 3% of CaO, 0% to 18% of ΣRO (where R represents Mg, Ca, Sr, Ba or Zn), 0% to 1% of ZrO2, and 0.1% to 7% of a coloring component having at least one metal oxide selected from the group consisting of oxides of Co, Mn, Fe, Ni, Cu, Cr, V and Bi.