SYSTEM FOR PRETREATMENT OF ZINC PHOSPHATE, WHICH DOES NOT CONTAIN NICKEL Russian patent published in 2020 - IPC C23C22/12 C23C22/78 

FIELD: metallurgy.

SUBSTANCE: invention relates to preliminary treatment of metal substrate. Disclosed is a system for pretreating a metal substrate, comprising an activating washing liquid for treating at least part of a substrate, which contains a dispersion of metal phosphate particles, having D90 particle size of not more than 10 mcm, wherein the metal phosphate contains bivalent or trivalent metals or combinations thereof and a dispersant comprising non-ionic polymers obtained from monomers comprising propylene oxide, ethylene oxide or a combination thereof, and also comprising a pretreatment composition for treating a substrate treated with said activating washing liquid containing zinc ions and phosphate ions. Pre-treatment composition contains practically no nickel, and D90 particle size relates to a volume-weighted distribution of particles, in which 90 % of particles have a diameter less than the value of D90. Also disclosed is a method of processing a substrate using said substrate pretreatment system and a substrate treated with a substrate pretreatment system.

EFFECT: invention provides more complete coating of substrate surface with centres of nucleation, which leads to more complete coating of substrate surface with subsequently applied preliminary treatment composition containing metal phosphate without nickel.

14 cl, 5 tbl