APPLICATION OF PHOSPHATE-POLYMER COATING ON CARTRIDGE CASE SURFACE Russian patent published in 2015 - IPC C23C28/00 C23C22/07 

FIELD: process engineering.

SUBSTANCE: invention relates to production of cartridges and can be used for application of protective polymer coating of steel cartridge case surface. This process comprises cartridge case degreasing and etching, flushing with hot and cold water, making of phosphate film on its surface, passivation and application of coating with subsequent drying. Note here that phosphate film is formed on cartridge case surface in at least two baths. Nuclei of centre are created on cartridge case surface in said first bath in aqueous mix of Foscon-26 concentrate while phosphate film is created in produced in the next baths. Thereafter, cartridge case is passivated in the solution of potassium bichromate and subjected to air drying. Passivated phosphate film is impregnated with water mix of polyorganosiloxane butadiene copolymer with styrene. Excess composition is removed by turning over in air. Additionally, cartridge case coating is compacted and thermally processed. First, said coating is dewatered and, the, polymerised.

EFFECT: reliable, long-life coating.

2 cl, 4 dwg, 1 ex