Nano hydrated silicon dioxide super-hydrophobic modification preparation method

Abstract

The invention relates to the technical field of white carbon black modification methods, in particular to a super-hydrophobic modification preparation method of nano hydrated silicon dioxide, which is characterized in that more than two preferably selected silane coupling agents are compounded and are subjected to gas-solid reaction with nano hydrated silicon dioxide, so that hydroxyl in the nano hydrated silicon dioxide is eliminated, and the nano hydrated silicon dioxide is changed into lipophilicity; in order to enlarge and deepen the application and field of preparation of high-temperature-resistant oil paint and environment-friendly waste oil absorption products, in the invention, after modification reaction is completed, a reaction kettle is subjected to primary pressure relief to remove most ammonia gas, then a pressure relief valve is closed, nitrogen is introduced into the reaction kettle to pressurize the reaction kettle again, pores are filled with the nitrogen, and the nitrogen is introduced into the reaction kettle to fill the pores; the residual ammonia gas is thoroughly removed through pressure relief and vacuumizing again, so that the purpose of preparing the super-hydrophobic nano hydrated silicon dioxide product is achieved, and the acid-base balance of a using system is not influenced.

Description

technical field [0001] The invention relates to the technical field of silica modification methods, in particular to a preparation method for superhydrophobic modification of nanometer hydrated silica. Background technique [0002] Nano-hydrated silica, also known as nano-silica, is widely used in rubber reinforcing agent, ink thickener, spray material, matting agent and other fields. Due to the existence of a large number of active hydroxyl groups in nano-hydrated silica, it has It is hydrophilic and has poor compatibility with organic substances, which limits its scope of use. When used in the fields of room temperature vulcanized silicone rubber, inks, paints, coatings, adhesives, high-efficiency thermal insulation materials, defoaming agents, and dry powder fire extinguishing agents, most of them require hydrophobic treatment. At present, there are various production methods for hydrophobic modification of nano-hydrated silica, most of which use a single additive treatm...

AI Technical Summary

Problems solved by technology

At present, there are many production methods for the hydrophobic modification of nano-hydrated silica, most of which use a single additive treatment process, the amount of treatment agent is large, the time is long, the energy consumption is high, and the efficiency is low. It is difficult to prepare methanol with a value greater than 70. superhydrophobic products

At the same time, because there are a large number of pores between the nano-hydrated silica particles, the adsorption is very strong, and the by-products of the modification reaction tend to remain in the pores, which are difficult to completely remove and affect the pH of the prepared hydrophobic silica. Silicon is used in the organic phase of the polysiloxane system, partial acid or partial alkali will affect the acid-base balance of the organic phase, and even cause polycondensation or decomposition of polysiloxane

Seriously affect product performance

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