DE1281217B - Bath for the electrolytic removal of galvanic deposits from ferrous basic bodies - Google Patents

Description

EDITORIAL

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P 12 81 217.8-45 (B 92263)

April 27, 1967

October 24, 1968

The invention relates to a bath for the electrolytic stripping of galvanic deposits iron-containing bodies, which from an aqueous solution of sodium, potassium, calcium or Ammonium nitrate.

When electroplating objects such. B. of car bumpers or camera housings, If the coatings are defective, these defective coatings must first be removed again before the objects can be electroplated again. A mechanical removal Defective coatings require a lot of work and high costs and are more complicated designed objects mostly not feasible. It is known to produce such coatings by dipping To remove the objects in a suitable chemical bath, however, require such chemical Baths very long removal times, which is why this process is uneconomical. Beyond that such chemical baths are used up very quickly and accordingly have to be replaced frequently.

Such defective coatings can be removed electrolytically more effectively and faster, the object to be treated being immersed in the bath as an anode. Of the many, for this one For the purpose already known baths are best those that contain an aqueous solution of sodium, Contain potassium, calcium or, in particular, ammonium nitrate (US Pat. No. 2,549,411). but Various deficiencies also occur when working with such baths. So is the spread or In-depth effect in the case of electrolytic stripping with the baths mentioned is poor. In practice it is always to observe again that the defective coatings at deeper corners and nooks and crannies of the objects not or at most very slowly. It can also be used with the well-known, nitrate containing baths only very slowly remove matt and semi-gloss nickel coatings.

The invention is based on the object of a bath for the electrolytic removal of galvanic coatings to create ferrous base bodies, which have the aforementioned disadvantages of the known Baths no longer has.

The invention consists in adding phenol and / or nitrophenol in an amount of 0.1 to 0.5 percent by volume to a bath consisting of an aqueous solution of sodium, potassium, calcium or ammonium nitrate. The bath can be used for electrolytic detachment
galvanic precipitation
of ferrous bodies

Applicant:

Bergische Metallwarenfabrik,

Dillenberg & Co. K. G.,

5601 Gruiten, Millratherstr. 36

Named as inventor:
Horst Dillenberg, 5657 Haan

Contain 50 to 200 grams of ammonium nitrate per liter of water.

As extensive practical tests have shown, the addition of such a phenol the scattering and depth effect in the electrolytic detachment improved very much, so that too in the case of very complex objects, complete detachment in all corners and angles the galvanic coatings is achieved. The added phenol or nitrophenol also has an effect as an accelerator, which is particularly evident when removing matt or semi-gloss nickel occurs. While matt or semi-gloss nickel coatings with one containing only ammonium nitrate Bath can only be removed for hours or days because of the clogged Phenol reduces the release time to 10 to 20 minutes.

A favorable degree of efficiency is achieved at a voltage of 15 V and a bath temperature of 60 ° C obtain.

Claims (1)

Claim: Bath for the electrolytic removal of galvanic coatings from ferrous base bodies, consisting from an aqueous solution of sodium, potassium, calcium or ammonium nitrate, thereby characterized in that it additionally contains phenol and / or nitrophenol in an amount of 0.1 to 0.5 percent by volume. Considered publications:
U.S. Patent No. 2,549,411.