The invention discloses a
silicon dioxide anti-blocking agent and a preparation method thereof, and relates to the technical field of
chemical preparation. Comprising the following steps: taking a water glass solution and a dilute sulphuric acid solution as raw materials, and carrying out parallel flow mixing reaction to prepare
silica gel; the method comprises the following steps: crushing
silica gel, transferring the crushed
silica gel into a reaction kettle, adding an aprotic
organic solvent, adding a pH
buffer solution and organic alkali into the reaction kettle to adjust the pH value of the solution, carrying out heating
reflux to carry out an aging reaction, stopping heating after the reaction is completed, opening a filter valve, and filtering the liquid into an alkaline
recovery tank; continuously adding an aprotic
organic solvent and an
organic acid acidification
system into the reaction kettle to adjust the pH value of the solution, aging, opening a filter valve to filter the liquid into an acidic
recovery tank, washing gel to be neutral, and filtering washing water into a
water recovery tank; and adding high-purity water into the reaction kettle, homogenizing and emulsifying to prepare
slurry,
drying and crushing to obtain the
silicon dioxide anti-blocking agent product. The preparation cost is reasonable, the treatment method is simple, and the obtained product is fine and smooth in hand feeling, high in transparency and high in yield.