METHOD OF OBTAINING PROTECTIVE COMPOSITE THERMOPLASTIC COATING AND METHOD OF THEREOF APPLICATION Russian patent published in 2015 - IPC C09D151/00 

FIELD: chemistry.

SUBSTANCE: method of obtaining protective composite thermoplastic coating includes melting mixture of homo- or copolymer of propylene and ethylene and/or ethylenepropylene cauotchouc, as well as ethylene, grafted with functional monomer, such as carboxylic acid and its derivative, such as maleic acid, which includes grafting of monomer in quantity, controlled by infrared spectroscopy and sufficient for obtaining in final composition of 0.1-0.5 wt. p. of maleic anhydride, by heating of polymers at 150-280°C in presence of radical initiator, selected from the group - tertbutyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-tert-butyl peroxide, tert-butylcumene peroxide, methylethylketone peroxide, following mixing of components with addition of dye and complex of stabilisers, such as pentaerythritol tetrakis -3-(3,5-ditertbutyl-4-hydroxyphenyl)propionate; 2,6-di-tert-butyl-para-cresol; tris(2.4-di-tert-butylphenyl)phosphite; disteryl thiodipropionate, temperature of melt must be 100-250°C. Also claimed is method of applying protective thermoplastic coating by extrusion, which includes processing external surface of tubes from fat pollutions by jet-abrasive method, and purified surface of pipes is subjected to preliminary chemical processing, such as chromating, pipes are heated to temperature not higher than 250°C and epoxy primer is applied, after that layer of thermoplastic coating, obtained by method in accordance with i.1 is applied by extrusion at melt temperature at output from extruder 240-250°C.

EFFECT: invention makes it possible to obtain composition, which has high adhesion and protective qualities.

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