CS200099B1 - Passivating agent for the protection of metals - Google Patents

Description

(54) Passivating agent for metal protection

The present invention relates to a passivating agent for the protection of metals in the form of a melt, emulsion solutions.

At present, metallic materials exposed to the combined effects of atmospheric corrosion are protected by various coatings, organic and inorganic coatings, eventually by metallization. Particularly used are lead pigments, which, while providing sufficient and long-term protection of the metallic material, but due to the toxicity of the lead compounds, tend to limit their use.

In the case of protection of metal parts against atmospheric corrosion by means of common organic coatings and coatings, blisters and flaking often occur, most often caused by imperfect treatment of the base material. Most of the organic coatings used are at least partially permeable to gases and water, often causing corrosive attack on the parent metal and again leading to peeling and degradation of the protective layer. Sometimes the above-mentioned deficiencies can be stimulated by various bacteria and microorganisms depending on the nature of the aggressive environment.

In the case of metallization of steel materials, the high consumption of deficit metal is often a defect.

These drawbacks are overcome by the passive metal preservative according to the invention, which comprises 5 to 98 wt. aliphatic amines, preferably octadecylamine,

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0.5 to 20 wt. % metal dust, in particular metal oxide of zinc, aluminum, cadmium, tin, lead and lead, 0.1 to 1 wt. % imidazoline derivatives, 0.1 to 1 wt. salts of higher fatty acids with a carbon content of C _{12 22} or naphthenic acids, preferably zinc or aluminum, and / or esters of higher fatty acids with a carbon content of ≤ 5 ⁱⁿ an amount of 1-10% t HMO.

For the application of the passivating agent in the form of an emulsion, it additionally contains an emulsifier, preferably a condensation product of higher alcohols or acids with ethylene oxide. For the application of the passivating agent in the form of a solution, it additionally contains a solvent, preferably alcohols, chlorinated hydrocarbons or esters of lower alcohols and lower acids, optionally contains an inorganic passivator, preferably nitrite, silicate, phosphate in an amount of 0.1 to 3% by weight.

The passivating agent of the invention may also be applied in the form of a melt.

The passivating agent according to the invention has a number of advantages over other methods of protection against atmospheric corrosion. It utilizes primarily the synergistic anticorrosive effect of aliphatic amine and metal dust or metal oxide dusts, whereby the free electron pair of the amine group -NHg interacts with the active surface of the protected metal and on the other hand electrochemical protection with scattered metal or its oxide.

The application of the composition according to the invention does not require a perfect surface treatment, for example by phosphating, as with conventional coatings. The surface of the formed film is hydrophobic and thus ensures safe isolation of the base metal surface from moisture.

Another advantage is the bactericidal effects of higher aliphatic amines, which greatly reduces the adverse effects of bacteria and microorganisms on the base metal surface and on the protective coating. Due to the favorable melting point, the composition according to the invention also adheres to sharp edges and thus guarantees their protection.

The invention is illustrated by the following examples.

Example 1

Octadecylamine melt is used to protect the bridge structure at a temperature of 60 ° C with the addition of 10% 2n of spray dust.

Example 2

Common metal parts exposed to aggressive atmospheres are protected by painting or spraying with the following composition:

up to 30 wt. octadecylamine,% aluminum dust and

0.5 wt. imidazoline derivatives, a chlorinated hydrocarbon residue, 1,1,2 trichlorethylene or an alcohol.

Example 3

Less accessible areas are sprayed with an aqueous emulsion of composition:

% wt. % octadecylamine, wt. cadmium dust 1 wt. % zinc stearate, wt. esters of higher fatty acids with higher alcohols; and

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0.1 wt. emulsifier, polyethylene glycol, the rest water

Claims (3)

SUBJECT OF THE INVENTION Ϊ. A passive metal preservative comprising 5 to 98 wt. % higher aliphatic amines, preferably octadecylamine, 0.5 to 20 wt. % metal dust, in particular metal oxide of zinc, aluminum, cadmium, tin, chromium and lead, 0.1 to 1 wt. imidazoline derivatives, salts of higher fatty acids with a carbon content _and gg g naphthenic acids, preferably zinc or aluminum in an amount of 0.1 to 1 wt.%, and / or esters mastnýoh acids with higher alcohols having a carbon content _and ^G-5 % of 1 to 10 wt. Passivating agent according to claim 1, characterized in that it comprises an emulsifier, preferably a condensation product of higher alcohols and / or acids with ethylene oxide. Passivating agent according to claim 1, characterized in that it contains a solvent, preferably alcohols, chlorinated hydrocarbons or esters of lower alcohols and lower acids, optionally with an inorganic passivator, preferably nitrite, silicate, phosphate, in an amount of 0.1 to 3% by weight. .