HOT MELT ADHESIVE POLYMER COMPOSITION Russian patent published in 2024 - IPC C09J123/26 C09D123/26 

FIELD: chemistry.

SUBSTANCE: invention relates to adhesive compositions based on ethylene copolymers, which can be used as coatings for protecting steel pipes from corrosion. Polymer composition of the hot melt adhesive contains two random ethylene copolymers, an inorganic filler, a modifying additive and a graft copolymer of ethylene and maleic anhydride with maleic anhydride content of 0.5–2.0 wt.%. First ethylene copolymer used is a copolymer of ethylene with vinyl acetate containing 5–30 wt.% of vinyl acetate groups, second ethylene copolymer is a ternary copolymer of ethylene, alkyl acrylate and maleic anhydride with content of 5–15 wt.% alkyl acrylate groups and 2.8–3.6 wt.% of maleic anhydride groups with melt flow index of 3–40 g/10 min and melting point of not less than 80°C. Inorganic filler is selected from ground mica, chalk or talc. Modifying additive used is a polyisocyanate, or a high-molecular weight aromatic amine, or γ-aminopropyltriethoxysilane.

EFFECT: invention increases adhesion strength at high temperature of the hot melt adhesive to metal and epoxy primer, as well as reduces the rate of cathode peeling of the coating.

1 cl, 2 tbl, 12 ex