The invention relates to the technical field of nano material preparation, in particular to a hydrophobing agent and a method for preparing hydrophobic white
carbon black at low temperature by adopting the hydrophobing agent. Comprising the following steps that 1, 3-divinyl-1, 1, 3, 3-tetramethyldisilazane and 1, 1, 1, 3, 5, 5, 5-heptamethyltrisiloxane are mixed, a Pt catalyst is added, the mixture enters a micro-channel reactor, a heating reaction is carried out, the mixture enters a reaction kettle to continue a stirring reaction, reaction heat in the micro-channel reactor is used for heating the reaction kettle, and unreacted components are removed; distilling to obtain a
water repellent agent, and recycling a kettle substrate as a catalyst; the preparation method comprises the following steps: mixing white
carbon black and a hydrophobic agent under the protection of
nitrogen or
inert gas, and heating and stirring to obtain the hydrophobic white
carbon black. The hydrophobic agent disclosed by the invention contains a
silicon-
nitrogen bond with good reaction activity and is rich in lipophilic trimethylsiloxy. The
silicon-
nitrogen bonds can be effectively reacted and grafted with the surface of the white carbon black to form stable chemical bonding.