DE1910475A1 - New disazo dyes - Google Patents

Description

The invention relates to new disazo dyes of the general formula

R ^ Jk ^ N »N - A- N = N

in which A denotes an optionally substituted benzidine radical, which is free of carboxyl and sulfonic acid groups, and R represents a hydrogen atom or a carbamoyl radical, and a method for the production of such dyes and their use as Pigments. ,.

Substituents for the radical A include, for example, chlorine, bromine, Alkyl, alkoxy, nitro or carboalkoxy are suitable.

In addition to the substituents mentioned, e.g. methyl, Ethyl,. Methoxy, ethoxy, carbomethoxy or carboethoxy called.

Dyes - the substituents are chlorine, methyl, ethyl, methoxy or ethoxy are preferred.

Residues Aj, which may be contained in the dyes according to the invention, are, for example, the residues of g -benzidine, ^^^ '- dichlorberiziäin, a ^ a ^ dichlorobenzidine, 3,3'- dibromobmzlüin _s 5,3 ^? -pimethyXbenzidin, a ^ '^ dimethylbenzidine, 3,3'-di-

_s 3,3'-dicarbomethyl

; D1 © la 3,3 ^ position-substituted boric acid are preferred.

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The new dyes are obtained, for example, by tetrazotizing Benzidines of the general formula II,

H ₂ NA-NH _{2 ττ} jfV ^R III

HO ^ N ^ OH

in which A has the meaning given for formula I, and coupling with dihydroxypyridines of the general formula III, in which R has the meaning given above. Tetrazotization and Coupling are preferably carried out in aqueous solution, but can Additions of solvents or dispersants or emulsifiers be beneficial.

The new dyes are suitable as pigments. In dependence of the substitution of the benzidine residue gives orange to blue connections. The properties of the pigments, in particular the fine distribution, depend on the production method and can be done through measures known from the literature, such as re-flow: Heating in solvents or grinding with grinding aids / influenced and adapted to the respective purpose *

The new pigments can be used, for example, in printing inks or paints or used to color plastics in bulk.

r The paints that can be used are, for example, acrylates, melamine resins, urea-formaldehyde condensation products, alkyd resins or also contain varnish. Printing inks with the new pigments can e.g. be used in letterpress or offset printing or in textile printing.

As synthetic materials 'which are colored with the' compounds of formula I. let, be e.g. * polyvinyl chloride ^, polystyrene or rubber called.

With the. new strong una -brillanten), Pigment® ». @ r-zi $ lt __ man. . ^; good Lioht-, Öl-, Überlaaicier-j: "" öberspritz- und Migrations® oht <=> ._-

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In the following examples, the details refer to parts and percentages on weight.

example 1

10.6 parts of 3,3'-dimethylbenzidine are tetrazotized in water as usual. The tetrazonium salt solution is gradually allowed to dissolve of 16.8 parts of 2,6-dihydroxy-4-methylnicotinamide in 5 percent Run in sodium hydroxide solution and stir for 2 hours. After this the pH value has been brought to 2, the mixture is stirred for a further 30 minutes, Then sucks off the precipitated dye and washes it with it hot water. The aqueous dye paste obtained is labeled 11 Stir alcohol for 2 hours, then suck off and wash again. The dye is then heated in 1 1 of toluene to Boiling, the water still contained in the dye paste being mixed with alcohol azeotropically distilled off with the toluene. The operation is finished when only toluene is distilled over. After the again Suction ,; Washing and drying give 23.5 parts of a violet pigment powder. _

Example 2 \

25.4 parts of dichlorobenzidine, which tetrazotize as usual in aqueous solution are allowed to gradually dissolve 26 parts of 2,6-dihydroxy-4-methylpyridine in 250 parts of a 10 percent Run in soda solution, keeping the reaction mixture alkaline during the coupling by adding more soda solution. Man stir for a further 2 hours, then carefully acidify with diluted Hydrochloric acid, stirred for 30 minutes, filtered off with suction and washed well Water after. The aqueous color paste obtained is mixed with 1 l of methanol boiled, vacuumed, washed and dried. 49.6 is obtained Parts of an orange-red pigment powder.

If you work analogously to Examples 1 and 2, use however instead of the benzidines indicated there 1/10 mol of that in the table below listed amines, pigments are obtained in the specified amounts and colors:

^; - -4 -00 9 8 36/1707

Example R H- Amine; hue yield Parts 3 H 2,2'-dichlorobenzidine yellow 43.6 Parts 4th H ■ 2,2'-dimethylbehzidine yellow 24 Parts .... 5 H 3,3'-dichlorobenzidine yellow 49.6 Parts 6th H 3,3'-dimethylbenzidine violet 47 * 6 Parts 7th H 3.3 ^f -dimethoxybenzidine violet 45.4 Parts 8th CONH ₂ 2,2 ', 5,5'-tetrachloro
benzidine yellow 46 Parts 9 CONH ₂ 2,2'-dichlorobenzidine orange 52 Parts 10 CONH ₂ 2,2'-dimethylbenzidine yellow 30.8 Parts 11th CONH ₂ 3,3'-dichlorobenzidine red-violet 38.2 Parts 12th CONH ₂ 3,3'-dimethylbenzidine violet 42 Parts 13th CONH ₂ 3,3'-dimethoxybenzidine violet 45.7 Parts 14th Use in 2,2 ', 5,5'-tetrachloro
benzidln yellow 52 .-ν, .-- ".-.- ■ - Printing inks

1 part of the pigment prepared according to Example 1 is given a '10 Parts of the linseed oil varnish rubbed on a three-roller mill. The on this Well-produced printing ink gives when used in letterpress printing blue-violet prints with excellent brilliance and good lightfastness. Similar results are obtained when using the pigments given in Examples 2 to 14, and prints with corresponding color shades are obtained.

Use in stoving enamels

95 parts stove enamel mixture, consisting of 67 parts coconut oil resin, 17 parts of urea-formaldehyde resin and 16 parts of ethylene glycol are mixed with 8 parts of the pigment described in Example 1 the funnel mill rubbed. The blue-violet paint obtained in this way, after stoving onto sheet metal, cardboard or aluminum foil, gives blue-violet colorations with excellent overspray fastness. Similar Results are obtained when using the other pigments prepared according to Examples 1 or 2, the in the color shades given in the table.

Use in plastics '

A mixture of 70 parts of polyvinyl chloride, 30 parts of DiisooktyΙΟ 0 9 8 3 6/1, 7 0 7 -5-

phthalate and 1 part of titanium dioxide is mixed with 0.5 parts of the pigment obtained according to Example 1 in a roller mill which is based on
heated to 160 °, colored in the usual way. A blue-violet mass is obtained from which, for example, films or profiles can be produced. The dyeing is characterized by high brilliance and good plasticizer fastness. Similar results are obtained when using the pigments described in Examples 2 to 1'4.

-6-

00 9836/1707

Claims (4)

Claims CH, CH, in which A denotes an optionally substituted benzidine radical which is free from carboxyl and sulfonic acid groups, and R represents a hydrogen atom or a carbamoyl radical. 2. Dyestuffs according to the formula in claim 1, in which A is optionally one benzidine radical substituted by chlorine, methyl, ethyl, methoxy or ethoxy and R has the meaning given Has. . . 3. The use of the dyes according to claim 1 as pigments. 4. Ein'Verfahren for the preparation of dyes according to claim 1, characterized in that tetrazo compounds of amines of the formula HpN - A - NHp with couplable 2,6-dihydroxypyridines of the general formula III. III clutch. Badische Anilin- & Soda-Fabrik AG