LUSTRE FORMING ADMIXTURE INTO SEMI-LUSTROUS NICKEL PLATING BATHES

摘要

The brightening admixture is composed of salts of carboxyl acids with alkaline metals, derivates of the acetylenic compounds, water and pyridine derivates of the general formula 1, where R1, R2, R3 - -H, aliphatic alkyl with C1 to C8, aliphatic alkenyl with C1 to C8, formula 2, formula3, n - 1 to 8, -COOH, CONH2, -SO3H, -OH. It always contains at least one substance of the above-mentioned groups of compounds. It is able to suppress catalytic effect of the organic compounds residue deposited on the surface of objects with the deposited half-lustre zinc layer and thus efficiently prevent the passive oxidized layers from depositing. The active substances are contained directly in the nickel bath; it is unnecessary to activate the deposited coatings before further nickel plating. This admixture significantly reduces inter-layer flaking hence the level of defects in galvanic metallizing by multiplayer nickel coatings.<IMAGE>