Glass for chemical tempering

Abstract

The invention relates to glass used for chemical strengthening, the weight percentage component of the glass comprises 60 to 70 percent of SiO2, 3 to 8 percent of Al2O3, 4 to 8 percent of B2O3, 10 to 15 percent of Na2O, 3 to 8 percent of MgO, 1 to 5 percent of ZnO, 1 to 5 percent of Li2O, 1 to 5 percent of K2O. The melting temperature of the invention is lower than 1450 DEG C, the surface compressive stress is higher than 750 MPa, and the liquidus temperature is lower than 900 DEG C. The invention has good devitrification performance and is easy to be produced through down-draw process. The transformation temperature of the invention is lower than 500 DEG C, thereby being applicable for the low-temperature ion transformation. The invention has good ion transformation performance, the ion transformation layer of the chemical strengthened glass obtained by transformation in short time is 20 to 35 microns, the buckling strength is 550 to 650 MPa, and the hardness is 6000 to 7000 MPa, so the invention can be widely used in windows such as a watchcase and a cell phone faceplate.

Description

technical field [0001] The invention relates to a glass, in particular to a glass for chemical tempering. Background technique [0002] Chemical toughening is ion exchange enhancement, which is mainly divided into two types. The first type is low-temperature ion exchange, which is characterized in that it is lower than the glass strain temperature. Large ions in molten salt are used to exchange small ions in glass, resulting in a crowding effect. A compressive stress layer is formed on the surface of the glass, and the compressive stress layer is preserved after cooling to room temperature; the second type is high-temperature ion exchange, which is characterized by being higher than the strain point of the glass, generally above the annealing temperature, using small ions in molten salt Exchange the large ions in the glass to form a low-expansion layer on the glass surface. During the exchange process, the glass surface undergoes structural relaxation, but when the temperatu...

AI Technical Summary

Problems solved by technology

[0004] The chemical toughening glass disclosed in the above-mentioned Japanese Patent Laid-Open No. 5-3243 and US4156755 introduces more Al in the glass. 2 o 3 and ZrO 2 , resulting in too high melting temperature and forming temperature of the glass, which is not suitable for down-draw production; the ion exchange speed of the third tempered glass is slow, and the ion exchange layer of the glass obtained in a short time is shallow, and the bending strength is not good. Good, poor impact resistance

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