METHOD FOR SURFACE CROSS-LINKING OF POLYMER PARTICLES Russian patent published in 2018 - IPC C08G69/14 C08G73/14 C08J3/24 A61K8/88 

FIELD: chemistry.

SUBSTANCE: invention relates to a process for surface cross-linking of a polymer in the form of particles, to a process for polymerizing a polymer, to a composition, to a crosslinked particle of a polymer powder and its use. Said method for surface crosslinking of a polymer in the form of particles is that a crosslinking agent containing at least two functional groups interacts with functional groups of the polymer containing labile hydrogen atoms. And the crosslinking step is carried out at a temperature below the melting temperature of the polymer. Polyamide, polyamide imide or a mixture thereof is used as the polymer. As the cross-linking agent, compounds containing at least one isocyanate group are used. Above polymer’s polymerization process consists in that at first polymerization is carried out. Then, above step of crosslinking the polymer obtained in the form of a powder is carried out. And a polymer powder particle after crosslinking comprises one or more zones consisting of a polymer having one or more functional groups with labile hydrogen atoms and one or more zones containing the above polymer cross-linked with the cross-linking agent. Crosslinked powder particles are used to produce composite materials, structural adhesives, substrate coatings, carbon paper, for the manufacture of products by agglomeration of fusion powders caused by radiation, and are used as an additive in cosmetic compositions.

EFFECT: invention makes it possible to obtain polymer particles having good chemical resistance to solvents and low moisture absorption.

15 cl, 3 tbl, 3 ex