METHOD TO APPLY PROTECTIVE POLYMER COATING ONTO SURFACE OF STEEL CARTRIDGE CASE Russian patent published in 2011 - IPC C23C28/04 

FIELD: weapons and ammunition.

SUBSTANCE: method includes formation of phosphate layer used as ground, application of a polymer layer by means of the case treatment in an aqueous solution of a polymer composition and thermal treatment of the polymer coating. After the phosphate layer formation it is passivated in the aqueous solution of a passivating-stabilising additive with concentration of 10-15 g per litre of a working solution. The polymer layer is applied by means of the case treatment in the aqueous solution of a mix that contains 180-220 g of the polymer composition CKN-26 and 7-10 g of the passivating-stabilising additive with concentrations per litre of the working solution with provision of the pH values index for the whole working solution equal to 8.5-9.5. A mixture of the following solutions, wt %, is used as a passivating-stabilising additive: 1.8-2% solution of 2-mercaptobenzothiazole, dissolved in 12-15% aqueous solution of potassium carbonate or sodium carbonate - 90-93.5, 15% aqueous solution of the mixture of sodium hexametaphosphate and trisodium phosphate dihydrate salts taken at the ratio of 1:(1-2) - 6.5-10.

EFFECT: increased corrosion resistance of steel cartridge cases with polymer coating as a result of high stability of formed polymer coating.

6 cl, 1 ex