Ion exchange process for thin glass chemical tempering and fused salt

Abstract

The invention relates to a thin glass tempering treatment technology, and in particular relates to fused salt for thin glass chemical tempering and a production process thereof. The main component of the fused salt is KNO3, and the auxiliary component is KCl, K2CO3, KSb(OH)6 and gamma-Al2O3, the warming speed of a pre-heating furnace in the production process is 5+ / -0.5 DEG C per minute, heat preservation is performed for 30+ / -5 minutes after the temperature is raised to 350+ / -5 DEG C, and then the glass is placed in the fused salt so as to be subjected to the ion exchange; the glass subjected to the ion exchange is placed in an annealing furnace so as to be cooled, and the temperature of the annealing furnace is 300+ / -5 DEG.C; a power source is turned off after the glass is placed therein, so as to slowly cool to 50+ / -5 DEG.C, and then the glass is taken out so as to be cleaned, dried and packaged. The surface stress of the normal soda lime silica glass produced by the invention can achieve 650MPa and more, the stress layer depth can achieve 23microns and more; the surface stress of alkaline alumina silicate glass can achieve 850MPa and more, and the stress layer depth can achieve 40 microns and more.

Description

technical field [0001] The invention relates to a thin glass strengthening treatment technology, in particular to an ion exchange process and molten salt for chemical toughening of thin glass. Background technique [0002] With the development of information industry and optoelectronics industry, the application of ultra-thin flat glass is becoming more and more extensive, from traditional watch covers, instrumentation covers, etc. to plasma display protection screens, liquid crystal display protection screens, solar glass covers and mobile phone protection. It can effectively prevent impact and scratch damage on the screen surface of display products and prolong the service life of products. However, the strength of flat glass decreases sharply with the decrease of thickness, so the improvement of the strength of thin glass becomes more and more important. The physical tempering of glass was invented in the 1930s. After decades of development, it has played an important ro...

AI Technical Summary

Problems solved by technology

However, in the process of ion exchange, a certain proportion of KOH is introduced, and OH- is highly corrosive, and its corrosion on the glass surface can lead to a decrease in the light transmittance of the glass

[0010] In the patents published above, the components in the auxiliary salt that play a role in purification (protection) can only react with impurity ions such as Mg2+ and Ca2+ in the molten salt , produce precipitates, but can do nothing about the increasing Na + in the molten salt after the ion exchange reaction, and the enrichment of Na + can also affect the ion exchange, so that it affects the service life of the molten salt

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