SU933825A1 - Steel-degreasing composition - Google Patents

Description

I

The invention relates to the electrochemical treatment of metals, in particular, to the pretreatment (degreasing) of steel products before electroplating.

A known solution for the electrochemical degreasing of steel products 1 containing potassium hydroxide and polyethylene polyamine. Degreasing in this solution is carried out at 70-10 ° C and a cathode current density of 3-5 A / dm for 15-20 minutes. The indicated solution and process conditions ensure high quality of processing: the degree of dewatering is 97, which leads to an increase in the adhesion of the subsequent coating to the steel base (peeling of the coating does not occur until the sample breaks).

However, a high degree of purification is achieved in a known solution in 15–20 min, and at the currently operating automatic and semi-automatic galvanic lines, the electrochemical purification time is 2–6 min, in some cases the purification time is reduced to 1–0.5–0, 3 min. For 3 minutes in an electrolyte containing 350-500 g / l KOH and 0.5-1 g / l PEPA, the degree of degreasing is only 8c-85%. In addition, the service life of the known solution is insufficient 10 180 a / h / l.

The closest to the invention in terms of the composition of the solution is the known solution for the chemical degreasing of steel 2, containing sodium hydroxide (NaOH), sodium silicate (Na-SiOvSHjO), pyro- or orthophosphate sodium (Nadr Na-SiOn O or Ma PO 12H taline condensation product of sulfonic acids Formaldehyde sdispergator NF) and ethoxylated primary fatty alcohols of fraction С С; (sintanol DS-10). 39 However, the solutions used for degreasing steel and containing non-ionic antioxidants (Csintanol DS-10) have a stable performance in the temperature range of 60–75 ° C. At the site of this, some contaminants start to soften at temperatures above 75–80 ° C (fatty and synthetic greases, etc. The use of chemical degreasing only in a number of cases (black grease, mineral oils, pastes with a dropping point, greater than 90, and others) does not lead to a complete cleaning of the treated surface. the nature of the bond that occurs between the contaminant particles and the metal surface. To destroy them, an energy greater than the energy of the colloid-chemical interaction is required. Full cleaning in these cases is provided only by applying an electric field neither at the metal – solution interface due to polarization of the electrode, or due to mechanical separation of the contaminants by the gas evolved by the bubbles. The disadvantages of the known solution include the decrease in its efficiency (stability) at temperatures higher, due to a decrease in solubility and release of non-ionic surfactant from the volume of the solution to the air-to-PLV interface to the surface at 80 ° C, and the turbidity of the solution occurs already at 68 ° C). Surfacing of the surfactant leads to a decrease in the concentration of the organic additive in the solution, deterioration of the degreasing properties of the latter, the degree of purification is only 2 |) and, as a consequence, the adhesive and anti-corrosion properties of the coatings applied on the insufficiently cleaned surface (when tested in bending, the coating exfoliates after 1 3 bends). The aim of the invention is to increase the degree of surface degreasing and solution stability during electrochemical processing. This goal is achieved by the fact that the solution for steel degreasing containing sodium hydroxide, sodium silicate, pyro or orthophosphate sodium condensation product of naphthalene sulfonic acids with formaldehyde (disperser Nf) and ethoxylated primary fatty alcohols of fraction C, - (DS-10 sintanol) additionally contains organosilicate KE-10-01 type emulsion and N-alkyl (M-succinato) -succinamine sulfonate derivative in the following ratio of components, g / l: Sodium hydroxide 20-MO Sodium silicate 10-30 Pyro- or sodium orthophosphate 10-20 Disperser NF, 7 Sintanol DS-10 0.4-0.5 Derived N-alkyl (M-succinate) -succinamine sulfonate 0.1-0.6 Organosilicon Silicone Liquid, type KE-10-010.03-0.05 In this case, as a derivative of N-alkyl- {N-succinate} -succinamine sulfonate, the solution contains tetrasodium Z- (H-alkyl) - (M-succinato) -succinamine sulfonate (aspar F) in an amount of 0.1-0.3 g / l or disodium 3 -M (-3-decyloxypr1epil-M-diethylsuccinato) -succinamine sulfonate (wetting agent CB-lf 7) in an amount of 0.2-0.6 g / l. Electrochemical degreasing can be carried out both at the cathode and at the anode at a current density of 5–10 with a solution temperature of 80 using steel anodes and cathodes. The boiling point of this solution (depending on the concentration of inorganic salts in it) is in the range of 101-5 10.5 ° C. The introduction of asparala F or wetter CB-11 7 into the solution provides an increase in the degree of degreasing and the efficiency of the solution in the temperature range from to the boiling point of the solution. The presence of CE-10-01 does not affect the quality of surface cleaning, but is associated only with the need to lower the height of the foam layer on the bath mirror, which forms during electrochemical cleaning due to the intense evolution of gaseous hydrogen and oxygen. If the height of the foam exceeds 50-70 mm, this may lead to the formation of an explosive mixture of these gases (the height of the foam in this

5933825 6

case after 1 h of operation of the bath some additives and the danger of contamination

exceeds 25 mm). Adjustment of the plant-environment by the waste of the production is carried out on the basis of the station, and also allows to expand

methods for determining the containing-working temperature range and how

neither its components and the magnitude of the 5

surface tension at the boundary of the removal of various contaminants with the mixture - air. In addition, the processing results for examples of, the reduction of the foam layer provided 1 - 6 are presented in the table (reduces the consumption of organic

fattening is derived from a solid-Odavidov mixture. The invention can be isla with lube oil 1: 1). Used in preparation processes

The invention allows practically metals to apply treated and other types of coatings to galvanic coating.

surface (degree of degreasing soy-as applied to the factories of Minavtoproma,

is 97-98, versus tt2% in the past 5

nominal solution). When providing you, solutions containing surfactants that are supplied with a working capacity are soluble in import.

stable at transmission up to 400 A / h / l Expected technical and economic

surface-active additives, the non-effect of the replacement of imported surfactants, are sprayed up to the temperature with a high-quality degreasing composition

solution penalties, which in turn does not amount to 30,000 rubles per 1 mpn.

allows to reduce the consumption of an organic-treated surface.

Anode and (or) cathode - on current density. A / dm

Bath voltage, V

Duration of cleaning, min

5 6.5 8 5 6.5 8 2.8 2.5 2.2 2.8 2.5 2.2

1.5 0.3

1.5 0.3 3

Claims (3)

Claim 1. A solution for degreasing steel, contents of sodium hydroxide, sodium silicate, pyro- or phosphate sodium phosphate, the condensation product of naphthalene sulfonic acids with formaldehyde (dispersant NF) and ethoxylated primary fatty alcohols fraction C ₄₀ - C ^ ₀ (syntanol DS-10), due to the fact that, in order to increase the degree of degreasing of the surface and the stability of the solution during electrochemical treatment, it additionally contains an organosilicon emulsion of the type KE-10-01 and a derivative of N-alkyl- (Y-succinate) -succinaminosulfonate at next the ratio of components, g / l: " Sodium hydroxide 20-40 * · Sodium silicate yoo Pyro or ortho sodium phosphate 10-20 ⁵⁰ Dispersant NF oh, 5th, r Sintanol DS-10 0.4-0.6 Derived N-alkyl- (N-succinate) succinaminosulfonate. 0.1-0.6 Kremniyor Gani type liquid KE-10-01 0.03-0.05 2. The solution according to claim 1, with the exception that, as a derivative of N-alkyl- (L-succinate) -succinaminosulfonate, it contains 3 “tetrasodium (N-alkyl) - (N- succinate) succinaminosulfonate (Aspart F) in an amount of 0.1-0.3 g / l. ₍ 3. A solution of pop. ^ Characterized in that, as a derivative of N-alkyl- (N-succinate) succinate ^ aminosulfonate, it contains disodium 3 (M-Z'-decyloxypropyl-N-diethyl succinate) -succinaminosulfonate (wetting agent CB-1147) in an amount of 0.2 - 0.6 g / l.