THIN SAFETY GLASS HAVING IMPROVED MECHANICAL CHARACTERISTICS

摘要

A strengthened glass sheet product along with a process and an apparatus for strengthening a glass sheet are provided. The process comprises cooling the glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened glass sheets having improved breakage properties.

主权项

1. A thermally strengthened glass sheet:
the glass sheet having a thickness, expressed in millimeters, of t, a length, expressed in millimeters, of l, and a width, expressed in millimeters, of w, t being less than l and less than w; the glass sheet having a first major surface and a second major surface separated by the thickness t, the first major surface of the sheet being flat to 100 μm total indicator run-out (TIR) along any 50 mm or less profile of the first major surface; the glass sheet comprising a glass having a low temperature linear CTE, expressed in 1/° C., of αSCTE, a high temperature linear CTE, expressed in 1/° C., of αLCTE, an elastic modulus, expressed in GPa, of E, a strain temperature, expressed in units of ° C., of Tstrain, and a softening temperature, expressed in units of ° C., of Tsoft; the glass sheet having a thermally induced central tension of less than 300 MPa and greater thanP1CT(hCT)*t(2P2CT(hCT)+t)·E·[Tstrain·αCTEs+αCTEL·(Tsoft-Tstrain)]; in units of MPa; wherein P1CT is given by910.2-259.2·exp(-hCT0.143); P2CT is given by2.53+23.65(1+(hCT0.00738)1.58); and hCT is greater than or equal to 0.020 cal/s·cm2·° C.