DE2207848A1 - SOLUTION FOR SIMULTANEOUS CLEANING, DEGREASING AND REMOVAL OF THE LUBRICANT CARRIER LAYER FROM WORKPIECES MADE OF IRON AND STEEL - Google Patents

Description

METALLGESELLSCPiAFT Frankfurt (M), January 28, 1972 Akti eng esells chafΐ DrBr / MKu
Frankfurt (M)

prov. No. 69ΟΟ M

Solution for the simultaneous cleaning, degreasing and removal of the lubricant carrier layer from workpieces made of iron and steel

Before deforming metallic workpieces, it is common to chemical coatings, in particular phosphate layers to apply their surfaces and to perform the deformation in the presence of lubricants »The after deformation Residues on the surfaces are for further processing or use of the 1 / pieces in general disturbing, so that their removal is required.

For the simultaneous removal of the lubricant carrier layers and the lubricant residues, aqueous alkaline solutions based on soluble phosphates are often used. as Phosphates are salts of orthophosphoric acid and / or those of condensed phosphoric acids. However, it was found that the treated workpieces after leaving the cleaning zone, there is a considerable risk of rusting, especially in the transition zones occurs. The susceptibility to rust is at least partly due to the deformation of the workpieces and thus the change the surface structure of the material. In cyclic systems there can be long overtaking times occur between the cleaning bath and the rinsing baths. the with the Phosphaticsum: cleaned parts rust easily at. However, this is undesirable and very troublesome for aftertreatments, in particular subsequent phosphating.

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It has now been found that this disadvantageous susceptibility to rust can be avoided in that the cleaning solution soluble compounds of nickel and / or cobalt, preferably cobalt, are added.

The rust-inhibiting effect is already achieved with one addition of 0.05 g / l of the metal compound, calculated as cobalt and / or nickel, is achieved. Bring quantities above 10 g / l no further Vortej. 1. Preferably 0.1 to 2 g / l of the metal or metals are added.

Suitable cobalt salts are, for example, cobalt nitrate, cobalt sulfate, cobalt acetate and cobalt chloride. Suitable nickel salts are e.g. nickel nitrate, nickel sulfate, nickel chloride, nickel acetate.

As phosphates in the cleaner according to the invention preferably mainly those of condensed Phosphoric acids, especially pyrophosphoric acid, are used. The phosphate content is expediently 5 to 80 g / l, preferably 15 to 50 g / l, calculated as Pp ^ 5 * The aqueous cleaning solution usually has one pH value of 8-13, preferably the pH value is kept in the range of 9-12. Surface-active substances can be used to increase the cleaning effect of the aqueous solution and / or organic solvents can also be used. Suitable surfactants are, for example, anion-active surfactants, such as alkyl benzene sulfonates, fatty alcohol sulfates, or non-ionic surfactants, v / ie e.g. ethylene oxide addition products of alkylphenols or fatty alcohols. When using non-ionic surfactants, please note that these surfactants at the application concentration and temperature a sufficient one Have solubility, preferably are anion-active Surfactants use up / ends. The addition is appropriate

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Ο » ¹ - 3 g / l wetting agent. Organic solvents such as higher-boiling hydrocarbons (kerosene, petroleum glycols or polyglycols) are expediently used in quantities of 0.5 ~ 10 g / l.

The cleaning solution according to the invention can advantageously be produced from a solid cleaning concentrate. Such a concentrate preferably has the following composition:

10-99% Ka ₄ P ₂ O ₇

0-10 % ^Na 5 ^P 3 ° io

1-10% Co (KO ₃ I _2. 6 H ₂ O

0 - 5 % surfactant (s)

0-20 % solvent

The use of the cleaner according to the invention is based on the following examples are explained in more detail:

Example 1;

Intermediate stages from a Topfdärapferrohrverbindang, which with a Residual phosphate and lubricant layer contaminated if / pren, were in a detergent solution that

46 g / l Na _{/ +} P _? 0 "calc.

2 g / l ^Na 5 ^P 3 ° io ^calc

1 g / l polyethylene glycol (molecular

weight approx 4000)

Contained, cleaned for 10 min. at 95 ° C. After this time the phosphate and lubricant residues were completely removed from the workpiece surface. At the start of the cleaning process, the parts were slowly transferred over the course of 60 seconds to a full rinsing bath, where they were vigorously rinsed.

W & .ad of transporting the workpieces from the cleaning bath to the

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A strong rust film was found in the water rinsing bath.

In a ParaJüel experiment, 1.25 g / l Co (N0-z) ₂ · 6 H ₂ O (corresponding to 0.25 g / l Co) were added to the cleaning bath. No flash rust formation occurred on the workpieces in this test.

During the subsequent phosphating, when the Co-free cleaning bath was used, uneven surfaces were found Phosphate layers interspersed with rust are retained in the subsequent Deformation process led to considerable disruptions. When using the Co-containing cleaning bath, the result was no phosphating or deformation difficulties whatsoever.

Example 2r

In order to determine the influence of the Co concentration on the prevention of the formation of flash rust, the cleaning bath was used accordingly Example 10-5 g / l Co added in the form of cobalt nitrate. In the various cleaning baths were with Residual phosphate layer and lubricant-provided drawing stages cleaned for 10 minutes at 95 ° C. The cleaned parts were subsequently kept in the steam atmosphere of the cleaning bath until the formation of elug rust begins. The received Test results are shown in the table below

Tabel

In addition, the formation of flash rust begins after approx.

/ ^Co minutes

0 0.2

0.02 0.2

0.05 1

0.1 3

1.0 10

2.0 15

5.0 15

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Example 31

Instead of cobalt nitrate, 0.25 g / l Ni was added as nickel sulfate to the cleaning bath according to Example 1. When cleaning pulling stages, the time between cleaning and No rust film observed in the rinsing bath.

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Claims (1)

Pat ent a η s ρ r ü c h e Alkaline phosphate-containing aqueous solution for the simultaneous cleaning, degreasing and removal of the Schraiermitteltragerschicht workpieces of iron and steel, characterized _Λ that it is at least added 0.05 g / l cobalt and / or nickel in the form of a soluble compound. 2) Solution according to claim 1, characterized in that the addition of cobalt and / or nickel is at most 10 g / l, preferably 0.1 to 2 g / l. 3) The solution of claim 1 is characterized by marked in to 3 "in that it contains surfactants, preferably anionic surfactants. 4) Concentrate for the preparation of a solution according to claim 1 to 3, by mixing with V / water, characterized by the following composition: 70-99 % Na ₄ P ₂ O ₇ 0-10% ^Na 5 ^P 3 ° OK 1 - 10 % Co (N0 ₃ ) ₂ . 6 H ₂ O O - 5 % surfactant (s) 0-20 % solvent 0 9 8 3 7/1115