Method for preparing modified micro granules

Abstract

The invention discloses a method for preparing modified micro granules. Co-precipitation reaction is performed in aqueous solution and between the freezing point and the boiling point of reaction mother solution to generate the micro granules or mixed sediment of micro granule precursor and inorganic sediment. The problems of contradiction between granule micronization and surface modification and difficult separation of the micro granules and the reaction mother solution in the conventional method for preparing the modified micro granules are solved, and the brand-new industrialized production method for modified micro, submicron or nano granules is provided.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a preparation method of modified micronized particles. Background technique [0002] During the chemical reaction process of nucleation and growth, the water-insoluble micronized particles tend to have strong adhesion with each other, so that the micronized particles can only be used in the subsequent use with a particle size of several microns or even tens of microns. The size distribution in the filled substrate has extremely poor monodispersity (secondary particle size), and there is a significant gap in application performance compared with submicron or even nanoscale distribution of micronized particles. [0003] In order to obtain modified micronized particles with good secondary particle size, in the current industrial production, the preparation of such monodisperse micronized particles is generally achieved by adding small molecule dispersants under aqueous con...

AI Technical Summary

Problems solved by technology

However, since the active adsorption sites on the surface of the micronized particles prepared by this method have basically been occupied by the previous small-molecule dispersant and cannot be removed, this re-modification will become extremely difficult at this time. In other words, no matter how the micronized particles are treated, it is difficult to achieve the most ideal modification effect on the surface of the particles, which will inevitably be subject to many constraints in the next application.

For example, calcium carbonate prepared with sodium polyacrylate dispersant is difficult to be directly applied to polypropylene plastics. Even if it is re-modified by corresponding coupling agents, the interface fusion between it and polypropylene plastics will never reach the optimum level. Excellent results, resulting in an unavoidable considerable gap between it and in-situ polymerized nano-calcium carbonate in application performance

[0009] Secondly, in the traditional preparation process, the enrichment of the above micronized particles is also extremely difficult

Since the surface of the micronized particles is modified by a small molecule dispersant to be highly hydrophilic, and the small size of the particles makes it difficult to filter, it is difficult to separate the micronized particles from the reaction mother liquor, and there is a problem of micronized particle loss during the separation process