CHEMICALLY TOUGHENED GLASS ARTICLE WITH LOW COEFFICIENT OF THERMAL EXPANSION

摘要

The invention provides a lithium-free boron alumino-silicate glass composition which is chemically toughened and a glass article manufactured thereof. The glass article has a CTE lower than 7.5 ppm/K-1 at a temperature of 20 to 300°C, a Dol higher than 10 μm and a CS higher than 500 MPa. The glass article comprises a glass composition in accordance to the invention with the ratio R'O/R2O equal to or lower than 0.7 and wherein R' is at least one of Mg, Ca, Sr, Ba and wherein R is at least 10 one of Na and K. The non-bridge oxygen produced by alkali earth oxides can be controlled and the good chemical toughening properties (CS>500 MPa, Dol>10 μm) can be got. The glass has high thermal 15 shock resistance, high heat conductive coefficient and high surface tension. The chemical toughening low CTE glass article can be used as a cover for cellphones, smart phones, tablet PC, notebooks, PDA;20 or it can be used for flexible cover on folding screening display, OLED and the like.