DE1147457B - Wetting agent for galvanic baths - Google Patents

Description

The subject of patent 1133 957 is the use of acidic, halogen-free alkyl and alkaryl phosphoric acid esters with at least 8 carbon atoms in the molecule or their water-soluble salts as wetting agents in electroplating baths.

It has now been found in a further development of the subject matter of the main patent that halogen-free, acidic, from straight or branched acyclic or cyclic hydrocarbon radicals with at least Phosphonic acids derived from 6 carbon atoms or their water-soluble salts as wetting agents in galvanic baths, in particular chrome baths, are ideally suited, with primary alkyl and cycloalkylphosphonic acids with a terminal phosphonic acid group have proven particularly advantageous to have.

Examples of such phosphonic acids that are to be used as wetting agents are: n-Octylphosphonic acid-1, n-Dodecylphosphonic acid-1, n-Hexadecylphosphonic acid-1,2-ethylhexylphosphonic acid-1, n-Octylphosphonic acid-3, n-decylphosphonic acid-4 or mixtures of such alkylphosphonic acids in which the phosphonic acid group is on any Carbon atom of the chain sits, di-n-octyl, ethyl-n-decyl, methyl-n-undecyl, iso-octyl-n-dodecyl, Cyclohexylphosphonic acid, methylcyclohexylphosphonic acids or their water-soluble alkali, Ammonium, mono- or dialkylamine or mono- or dialkylolamine salts. The phosphonic acids used and their production are known.

The wetting agents according to the invention can be used in the known acidic nickel, copper, zinc and chromium baths as well as the alkaline, especially cyanidic copper, zinc, cadmium, tin, silver, Gold, brass or bronze baths are used. They are preferably used in these baths Amounts of 0.01 to 5 g / l added. The phosphonic acids are subject to a remarkably low level Consumption. In chrome baths in particular, they prevent the formation of annoying fog through formation a foam blanket. They behave indifferently towards gloss agents used at the same time let the shine-giving properties of these substances take full effect. Compared to the Phosphoric acid esters of the main patent have an even higher resistance in the baths mentioned above.

example 1

1 g / l of n-dodecylphosphonic acid-1 are dissolved in a bright chrome bath containing 300 g / l CrO _3. When chrome-plating bright nickel-plated objects with a wetting agent for galvanic baths

Addendum to patent 1133 957

Applicant:

Dehydag Deutsche Hydrierwerke G.m.b.H., Düsseldorf, Henkelstr. 67

Dr. Wennemar Strauss, Düsseldorf-Holthausen,

Dipl.-Ing. Gregor Michael

and Dr. Karl-Heinz Worms, Düsseldorf,

have been named as inventors

With a current density of 15 Amp./dm ² at 35 ° C, a foam layer about 1 cm high forms on the chrome bath, which completely prevents the occurrence of chromic acid mist. The bright chrome plating is not affected by the addition of dodecylphosphonic acid.

Example 2

In a hard chrome bath containing 250 g / l CrO ₃ , 0.2 g / l n-hexadecylphosphonic acid-1 and 2.5 g / l cyclohexylphosphonic acid are dissolved. The hard chrome plating carried out at 55 ° C on steel objects with 35Amp./dm ^{2 is high-gloss.} Due to the mixture of organic phosphonic acids used, the occurrence of chromic acid mist is completely suppressed as a result of the formation of a foam layer on the chrome bath.

Claims (1)

Claim. Use of acidic, halogen-free phosphoric acid derivatives as wetting agents in galvanic Baths, according to patent 1133 957, characterized in that acidic, halogen-free, differs from straight or branched acyclic or cyclic hydrocarbon radicals with at least Phosphonic acids derived from 6 carbon atoms or their water-soluble salts are used will. Considered publications:
Petroleum and Coal, August 1953, p. 455.