Molten salt for glass chemistry toughening and chemical toughening method using the same

Abstract

The invention discloses a molten salt used in glass chemical toughening. The components comprise at least one of KNO3 and KNO2, at least one of 15% of Al2O3 and 0.5%-10% of SiO2, 0.3%-6% of KCl, at least one of 0.3%-6% of K2SO4 and 0.3%-6% of K2SiO3 and at least one of 0.2%-5% K2CrO4 and 0.2%-5% of K2CO3. The invention also discloses a chemical toughening method to conduct ion-exchange treatment for the glass by the molten salt after pre-heating treatment. The molten salt and the chemical toughening glass prepared by the invention can have shock resistance of the glass with consideration to the cutting property and warp degree.

Description

technical field [0001] The invention relates to a molten salt used for chemical tempering of glass, in particular to a molten salt capable of taking into account the impact resistance, cuttability, warpage and other properties of glass. Background technique [0002] Glass chemical tempering forms compressive stress on the glass surface through ion exchange, which can achieve the effect of glass strengthening. Chemical tempering can be divided into two categories: [0003] 1. High-temperature chemical toughening, the reaction temperature is above the strain temperature of the glass (the temperature at which the glass begins to soften), and small ions (Li + ) to replace large ions in the glass (Na + ), generating β-eucryptite (Li 2 O·Al 2 o 3 2SiO2 2 ), so that the expansion coefficient of the glass surface is lower than the internal expansion coefficient of the glass. When the glass is cooled, the internal shrinkage deformation is greater than the surface shrinkage defo...

AI Technical Summary

Problems solved by technology

However, for ultra-thin flat glass with a thickness of 0.3-1.1mm and a size of more than 12 inches, the current low-temperature chemical tempering technology (using KNO 3 Molten salt) is difficult to meet the use requirements of ultra-thin flat glass, mainly in the performance of cutting performance, warpage and impact resistance are difficult to meet the standards at the same time

This is because after the glass is treated with the existing low-temperature chemical tempering technology, the impact resistance performance index of the glass is contradictory to the cuttability, warpage and other performance indexes, that is, the impact resistance of chemically tempered glass is good. That is to say, the anti-destructive performance under the action of external force is good, but the warpage of the glass is easy to exceed the standard, and it is difficult to cut

However, in the usual application fields of ultra-thin flat glass (such as LCD substrates, touch screen substrates, etc.), there are strict requirements on the impact resistance, cuttability and warpage of the glass, and the untreated original glass obviously cannot meet the requirements. The use of impact resistance is required, and the existing low-temperature chemical tempering technology can not take into account the impact resistance, cutability, and warpage of glass at the same time.