DE574674C - Process for the production of cobalt-containing azo dyes - Google Patents

Description

Process for the preparation of cobalt-containing azo dyes It has been found that valuable cobalt-containing dyes are obtained if o-oxyazo dyes of the general formula are used where R1 denotes an aryl radical which is not substituted by any group containing the SO2 group or by any carboxyl group, treated in a non-caustic or ammoniacal medium with cobalt-releasing agents.

Organic cobalt compounds in Presence or absence of organic or inorganic additives or inorganic Cobalt compounds in the presence or absence of organic or inorganic Additives are used.

It has also been found that similar metal-containing dyes can be obtained If the finished dyes are not converted into cobalt compounds by the above process transferred, but the complex cobalt compounds for the present process suitable o-oxydiazo compounds and these cobalt compounds combined with resorcinol to form the cobalt-containing o-oxyazo dyes.

The cobalt-containing dyes obtainable by the present process can be used to produce lightfast paints that are made up of cellulose esters and - derived from ethers, artificial and natural resins. ' Example r 2.74. Parts of the dye from diazotized 4-nitro-2-amino-z-oxyb? Nzol and Resorcinol are dissolved in 250 parts of hot water and 0.65 parts of cobalt appropriate amount of formic cobalt to boil for some time in the reflux condenser heated. After the reaction solution has cooled, the precipitated one is filtered off Dye off; washes out and dries at a moderate temperature Cobalt compound of the above-mentioned dye is a green-black powder which difficult in water, easy in caustic soda or concentrated sulfuric acid dissolves deep red or brownish yellow color. From a deep red colored solution in Za, ponlak vivid scarlet coatings of very good lightfastness are obtained.

The treatment with the cobalt-releasing agent can also be carried out in the presence of sodium formate, Alkali salts of other organic mono- and polycarboxylic acids, like sodium acetate, potassium tartaric acid, malonic acid, citric acid, succinic acid Sodium or mixtures of such alkali salts, e.g. B. from sodium acetate and sodium oxalate, be performed.

With formic acid cobalt with the addition of inorganic salts such as sodium sulfate, sodium chloride, secondary and tertiary sodium phosphate; similar cobalt lacquers are created. "Example e 7.2 parts of 4-chloro-2-amino @ -i-oxybenzene are diazotized in the usual way. The diazo compound is then neutralized in the cold and converted into a cobalt-containing diazo compound with an amount of cobalt chloride corresponding to 3 parts of cobalt coupled with resorcinol in an alkaline solution. The cobalt lacquer of the dye is formed directly, which is dried at a moderate temperature after separation and washing. The dye shows the same properties as those produced in the normal way by treating the finished dye with the cobalt-releasing agents Cobalt compound of the azo dye from diazotized 4-chloro-2-amino-i-oxybenzene and resorcinol. EXAMPLE 3 5.5 parts of the dye from diazotized 5-nitro-2-amino-i-oxybenzene and resorcinol are boiled in 40o parts of water and mixed with 4, 76 parts of crystalline cobalt chloride (Co Cl, # CH = O) and 5.44 parts of crystalline sodium acetate are heated to boiling for 5 hours The cobalt compound formed was deposited by sodium chloride, filtered and dried at a moderate temperature. It dissolves in water with wine-red, in 'caustic soda with violet and in concentrated sulfuric acid with orange color ..- It dissolves in "organic solvents. A solution of the cobalt compounds." In - commercially available zapon lacquers, on suitable substrates, lightfast bordea'.u # red coatings are obtained.

Claims (1)

PATENIA CLAIMS: i. Process for the preparation of cold-containing azo dyes, characterized in that o-oxyazo dyes of the general formula where R1 is an aryl radical which is not substituted by any group containing the S 02 group or by any carboxyl group, treated with cobalt-releasing agents in a non-caustic or ammoniacal medium. 2nd embodiment of the process according to claim i, characterized in that the diazo components converted into the complex cobalt compounds are combined with resorcinol.