Preparation method of double-particle-size-distribution polybutadiene latex

The invention provides a preparation method of double-particle-size-distribution polybutadiene latex. According to the method, self-made mixed solid acid (carbon-based solid acid and SO4 < 2->/TiO2/Al2O3) is adopted as agglomerating agents, the agglomerating agents are prepared into regular-shaped fillers to be filled in a fixed bed type agglomerating reactor, and polybutadiene latex with the small particle size of 80-120nm is agglomerated under the action of the two agglomerating agents with different acid strengths to obtain the double-particle-size distribution polybutadiene latex with the particle size of 250-350nm and the particle size of 450-600nm. The method provided by the invention is simple in process, a continuous process for simultaneously preparing the double-particle-size-distribution polybutadiene latex from a single material is realized, and the uniform pore structure of the carbon-based solid acid effectively avoids emulsion instability caused by collision of large-particle-size latex at an a