Study On Aging And Kinetics Of Chemical Masking Liquid For Cover Glass

Glass has excellent mechanical properties and chemical stability,and is widely used as the protective cover of electronic display screen.However,raw glass surfaces have a high reflectivity to light,resulting in glare problems that can be harmful to users and the environment.This paper,based on the citric acid,ammonium bifluoride and a variety of additives,had been formulated to conduct anti-glare treatment on glass.The change of physical and chemical properties and its influence on the effect of glass chemical masking were studied.Meanwhile,the dynamics and mechanism of glass masking had been explored,providing guidance for the formulation design of glass masking and the process optimization.The main contents are as follows:The prepared masking powder was prepared by adding water and aging at high temperature,and the chemical masking of glass was carried out by immersion method under constant temperature.XRD,EDS,Raman,Zeta potential,viscosity and acidity were used to characterize and analyze the masking liquid at different aging times.The results showed that there was a strong correlation between the acidity and viscosity of the masking solution and its properties,which could be used as a reference index to judge the masking solution’s aging.The aging time is 36 h,the effect of the glass treated at 30℃with masking solution for 5 min was better,its surface roughness was 254 nm,transmittance was 92.4%,haze was 82.9%,glossiness was 11.1 Gu,which had reached the control index of the enterprise masking processing requirements.The results showed that the aging of the masking liquid was primarily a citric acid process,in which ammonium bifluoride and a variety of additives interact to form stable fluorine-containing particles with etching activity.From the point of view of kinetics,the relationship between time,temperature,concentration of reactant and reaction rate was investigated.The results showed that the rate of glass masking could be significantly increased by increasing temperature and concentration of reactants except for masking time.The apparent activation energy E_a was 41.08 k J/mol,and the reaction order n is 0.4698.According to the experimental data,a mathematical model suitable for the shallow etching of glass was established by using power-law model,and its expression wasδ=1194.3261e^-4941.06/T C_t^0.4698?t（δis the etching depth.T is the reaction temperature.C_t is the reactant concentration,and t is the reaction time）.The results showed that the error between the results and the experimental data was small,and the chemical masking of glass could be accurately predicted in a short reaction time.The mechanism of glass masking was analyzed by measuring the composition of different concentrations of masking liquid in different time periods.The results showed that except F^-,H⁺,HF₂^-and（HF）₂ were the main active components in the chemical masking process.HF₂^-and（HF）₂ will nucleophilic erosion of Si atoms by H⁺catalysis,resulting in Si-O bond fracture,and the product would react with alkali metal ions in the glass to transform into fluorosilicate,and adhered to the glass.