US3120508A - Process for the manufacture of waterinsoluble azo-dyestuffs - Google Patents

Description

'idine, piperazine or pyridine.

United States Patent ()filice 3,120,508 Patented Feb. 4, 1964 3,12%,508 PROtJESS FOR TEE MANUFACTURE F WATER- llNSULUliLE AZO-DYESTUFFS @sltar Braun, Rudolf Frank, and Fritz fisterloh, all of Frankfurt am Main, Germany, assignors to Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt am Main, Germany, a corporation of Germany No Drawing. Filed Aug. 16., 1960, Ser. No. 49,827 (llaims priority, application Germany Aug. 20, 1959 Claims. (Cl, 260-161) From German Patents 889,042 and 930,998 it is known to use surface-active substances as emulsifiers together with oils in the manufacture of water-insoluble aZo-dyestuffs having a soft grain.

Now, we have found that water-insoluble azo-dyestuifs having a particularly high tinctorial strength can be prepared by adding during the coupling cationic surfaceactive compounds without simultaneously using oils. It was not to be expected that by the mere addition of relatively small quantities of cation-active compounds such an increase in the tinctorial strength of up to 40% would be achieved. The cationic surface-active compounds are generally added in quantities of about 1 to about preferably 1 to about 3%, referred to the dry dyestuff.

As cationic surface-active compounds there enter into consideration practically all such substances known, for example, all the substances of this kind described in the book Surface-Active Agents and Detergents by A. M. Schwartz, J. W. Perry and l. Berch, vol. II (1958), pages 103 to 119.

Suitable cationic surface-active substances are, for example, amino compounds that contain long-chained aliphatic rests of about 10 to 18 carbon atoms, or also the salts of such nitrogen compounds with carboxylic acids, such, for example, as formic acid, acetic acid, oleic acid, tallow fatty acid, lactic acid or mineral acids, for example, hydrochloric acid. In the first instance there enter into consideration: fatty amines, for example, coconut oil amine, oleyl amine, stearyl amine, and tallow fat amine, as well as the secondary and tertiary amines or quaternary ammonium compounds derived therefrom that may carry as substituents aliphatic, aromatic or oxethylated radicals, for example, alkyldimethyloxethylammonium chloride. Suitable are also oxethylated fatty amines in their secondary, tertiary or quaternary form. There are further mentioned by way of example: the condensation products of long-chained, in case also unsaturated, carboxylic acids with amines, in particular alkylenediarnines, alkylenetriamines, or alkylenepolyamines containing alkylene radicals of low molecular weight, for example, ethylene diamine, diethylene triamine, etc., as well as the secondary, tertiary or quaternary amines formed by alkylation of the mentioned condensation products, especially in the form of their Water-soluble salts with the above-mentioned acids. Further, there may be used fatty acid amides and esters of long-chained carboxylic acids With alkylol amines, for example, triethanolaminoleate, -stearate, and the like, further also cyclical, nitrogencontaining compounds, for example, long-chained rests containing derivatives of morpholine, imidazoline, piper- The above-mentioned amino compounds are used preferably in the. form of their carboxylic or hydrochloric salts.

The mentioned surface-active salts of amines may be added to the diazo component or they may be added together with the acidic diazo solution to the coupling component. It is, however, also possible to add the surfaceactive salts of amines to the suspended coupling component or to the alkaline solution thereof, to the precipitating acid, or even in the course of the coupling.

The process of the present invention can be applied without any restriction to all known insoluble azo-dyestuffs. By insoluble azo-dyestufi are meant such dyestuffs as are obtained by the coupling of diazo or tetra-azo compounds of amines that do not contain groups imparting Water-solubility with the coupling components usually employed in the pigment chemistry. As coupling components, there may be used, for example: naphthols, hydroxynaphthoic acid arylides, pyrazolones, acetoacetic acid arylides, and the like.

By the addition of surface-active salts of amines according to the invention, the dyestuff being formed is influenced with regard to its particle size in surprisingly favorable manner so that substantial gains in tinctorial strength are achieved and in many cases also purer shades are obtained. By the reduction of the particle size the dry content of the press cakes is increased up to 40%. This saves pressing space and reduces the drying cost. The reduced particle size becomes apparent in a remarkable increase of the density of the dyestufi' powder which, due to the reduction of the space required, brings obvious advantages in packing, transportation and storage.

A dyestuff press cake prepared according to this invention is advantageously distinguished from the usual press cakes by substantially better temperature stability during the drying, which also entails a greater storability of the dyestuff powder. Furthermore, a dyestulf powder prepared according to the invention is distinctly less electrostatically charged than an ordinary azo-dyestuff, which again entails a favorable result in that the dyestuff has a reduced tendency to dusting during manufacture.

The fact is also very surprising that a clear acceleration of the reaction during the coupling is caused by the addition of the surface-active salts of amines. The products prepared according to the present invention exhibit also the advantage, which is of importance for the technical use, that the surface-active compounds added protect the dyestuff grains during grinding and triturating. Thus, for example, in a conventional trituration with a barytes lake the tinctorial strength remains the same, Whereas it is reduced with the usual pigments. With the dyestuif preparations of the present invention, the well-known deadrubbing of the pigment does not occur. The dyestuff powders are less sensible to higher temperatures since they maintain their original tinctorial strength even after a four weeks heating to 60 0, whereas powders prepared in ordinary manner then distinctly lose their tinctorial strength.

The increase of the tinctorial strength achieved by the new process further entails the advantage that such pigments, compared with ordinary aZo-dyestuffs, can be blended in higher ratios. Thus, for example, there can be prepared 40% blends with substrata that have alfinity to varnish, for example, metal salts of organic soaps, resins and fatty acids, as well as fatty oils or mineral oils in emulsified form, which have tinctorial strengths corresponding to that of an unblended pigment prepared by the conventional coupling methods. For the blend there are suitably used in general water-soluble salts, for example, sodium, potassium or ammonium salts, which are then transformed into the corresponding difficultly-soluble heavy metal salts, for example, calcium, barium, nickel, strontium, magnesium, iron, chromium or aluminum salts. There may, of course, also be directly used the diificultly soluble salts formed previously. The blending may be effected either in the coupling solution or even later in the press cake.

The following examples illustrate the invention but they are not intended to limit it thereto Example 1 A water-insoluble aZo-dyestuff is prepared by diazotiz ing 91.2 parts by weight of 1-amino-2-nitro-4-methy1-benzene and coupling with 108 parts by weight of acetoacetylaminobenzene, by well stirring the coupling component into a weakly acetic medium before introduction of the diazo-solution and then adding 5 parts by weight of oleylaminacetate dissolved in hot water. The coupling is effected at 20 C. and at a pH between 4.5 and 5.5. After having terminated the addition of diazo-solution, the whole is stirred for minutes, then filtered and washed neutral. A press cake is obtained which has a dry content of 24.3%, whereas a press cake prepared under equal conditions but without the addition of oleylaminoacetate, has a dry content of 18.6% only. The press cake is dried at 60 C. There are obtained 204 parts by weight of a yellow pigment dyestutf which, when tirturated with oil, dyes a standard white pigment about 40% stronger and with a distinctly purer shade than a dyestutf coupled in the same maner but without oleylaminoacetate.

The dyestuff powder obtained after the grinding process distinguishes advantageously from a powder prepared without the addition of cationic compounds by an essentially higher density. Thus, for example, a quantity of about 72 kg. of dyestuff powder can be placed in a drum of 400 liters capacity compared to about only 54 kg. of a dyestulf powder prepared in conventional manner.

This advantageous change of the structural state of the dyestuff pastes and powders obtained by the process of the present invention becomes also apparent in a comparison of the specific surfaces and the mean particle size of a dyestuif powder according to the present invention with those of conventional powders. Whereas the latter exhibits a specific surface of about 17.3 m. g. and a mean particle size of about 0.23311. the dyestuif powder prepared by the above described process exhibits a specific surface of 27.4 m. /g. and a mean particle size of the primary and secondary particles of 0.147

Instead of oleylaminacetate there may be used in the above working method with the same result other fatty amino salts, for example, coconut oil amine, tallow fat amine and stearylamino-acetate, or the corresponding formic or lactic salts. Furthermore, the acetoacetylaminobenzene may also first be dissolved in an alkali hydroxide solution, and then precipitated with acid, for example, formic acid, in which the cation-active additives are dissolved. The cation-active additives may also be added to the alkaline solution of the coupling component either before precipitation with an acid or dissolved in the diazo solution, or simultaneously with the diazo-solution or in a later stage of the coupling process in dissolved form.

During the coupling the dyestuif can be blended in the following manner: The coupling liquor is added with 106 cc. of a calcium chloride solution of strength (prepared from commercial, anhydrous calcium chloride). To this liquor is then added within 30 minutes a solution of 239 parts by weight of sodium colophonate of 50% in 1.5 litres of water, the whole is stirred for 30 minutes, then filtered and washed neutral. After drying and grinding, ther is obtained a dyestufif containing 59.0 parts by weight of pure dyestuff, 40 parts by weight of calciumcolophonate and 1 part by weight of oleylaminacetate. Despite the large quantity of extenders, the tinctorial strength of this dyestuif powder corresponds to that of an unblended dyestuif prepared according to conventional processes.

The blending may, of course, also be effected by directly adding to the coupling solution the previously prepared calcium-colophonate. The press cakes may as well also be blended by kneading with resin soap.

Instead of the calcium colophonate, there may also be used for the blending the corresponding barium, magnesium, strontium, zinc, cadmium, nickel, aluminum, iron or chromium salts of resinous acids or also the diflicultly soluble free resinous acids. Furthermore, there may also be used fatty acids or the diflicultly soluble salts thereof, for example, stearic, palmitic, coconut-oil fatty acid as well as fatty oils or mineral oils, suitably in emulsified form.

Example 2 A water-insoluble azo-dyestuff is prepared by diazotizing in conventional manner 86.5 parts by weight of 1- amino-2-nitro-4-chloro-benzene and coupling with 109 parts by weight of 1-acetoacetylamino-2-chlorobenzene. The coupling component is dissolved in water that has been added with one part by weight of the disodium salt of the ethylene diamine-tetraacetic acid. Shortly before adding the diazo solution, 2.5 parts by weight of tallow fat aminacetate in form of an aqueous solution of 5% strength are added. The coupling proceeds at 10-15 C. and in a pH range of 3.8 to 5.5. After having terminated the addition of the diazo-solution, the whole is stirred for 15 minutes, filtered, washed and dried at 60 C. The yield is 196 parts by weight.

With a small addition of about 1.25% referred to the dry dyestui'f, there is already obtained a yellow pigment that exhibits in normal white blends a tinctorial strength stronger by about 25% and a purer shade than a pigment prepared without addition of tallow fat aminacetate.

Example 3 A water-insoluble orange pigment is prepared by tetraazotizing 76 parts by weight of 3,3-dichloro-4,4-diamidodiphenyl. The tetra-azo solution is added at 25 C. to an alkaline coupling solution consisting of 110 parts by weight of 1-phenyl-3-methyl-5-pyrazolone, 75 parts by weight of chalk and 12.0 parts by weight of oleylaminacetate, which is added in the form of an aqueous solution of 10% strength. After the introduction of the tetra-azo solution is terminated, the coupling liquor is adjusted by means of hydrochloric acid to a weakly acid value of pH 1-2. The coupling solution is then heated to the boil, boiled for one hour, filtered, washed, and the press cake is dried at 60 C.

The above working method yields a soft pigment which, after having been incorporated on the roller with rubber together with the required additives and after vulcanization of the mixture gives a substantially stronger shade than a pigment prepared without the cation-active coupling additive. Instead of the oleylaminacetate there may also be used equal or smaller quantities of the following compounds: coconut oil aminacetate, tallow fat aminacetate or stearyl-aminacetate. Instead of the acetic salts there may also be used with the same result the lactates thereof.

Example 4 A coupling solution consisting of 1800 parts by weight of water, 131 parts by weight of sodium hydroxide solution (45 volume percent) and 118 par-ts by Weight of acetoacetylamino-Z-methylbenzene is introduced into a mixture of 200 parts by weight of water, 1200 parts by weight of ice, 67 parts by weight of glacial acetic acid and 5 parts by weight of sodium alkylsulfamidoacetate. To this mixture is added a mixture of 56 parts by weight of glacial acetic acid and 106 parts by weight of sodium hydroxide solution (45 volume percent). Before introducing the tetra-azo solution, which was prepared by tetraazotization of 76 parts by weight of 3,3- dichloro-4,4'-diaminodipheny1 in usual manner, the coupling solution is added with 9.6 parts by weight of coconut fat aminoacetate in the form of an aqueous solution of 10% strength. After the coupling is complete, the mixture is boiled for one hour, filtered, well washed and the dyestufi press cake is dried at 60 C.

There is produced by the above working method a water-insoluble azo-pigment which, after incorporation with rubber with the additives required on the threeroller mill yields yellow dyeings of a distinctly stronger and more vivid shade than those obtained with a pigment prepared without addition of cation-active substances.

In the process described above, the coconut oil aminacetate may also advantageously be dissolved in the glacial acetic acid used or it may also be added separately to the coupling solution at the same time as the tetraazo-solution.

Example A water-insoluble =azo-dyeshufi is prepared by tetraazotization of 76 parts by weight of 3,3'-dich1-oro-4,4-diaminodiphenyl. The tetra-azo solution so obtained is added in the course of 1 /2 hours to the coupling component which was prepared by dissolving 112.5 parts by weight of acetoacetyl-ammobenzene in 1500 parts by weight of water and 76 parts by weight of sodium hy droxide solution (37.5 B.). To this alkaline solution of the coupling component are added, after dilution, further 1500 parts by weight of water and, after cooling with ice to 5 to 6 C., 10 parts by weight of coconut oil aminacetate dissolved in water and the acetoacetylaminobenzene is precipitated by adding parts by Weight of glacial acetic acid. After addition of 1 mole of sodium acetate, the solution is added at 12 C. with the tetra-azo solution. The whole is stirred for 30 minutes, filtered, washed neutral and dried at C.

There are obtained parts by weight of a yellow azo-dyestuif, which dyes a standard white pigment distinctly stronger shades than a similar dyestuff prepared without addition of coconut oil aminacetate.

When increasing the quantity of coconut oil aminacetate to, for example, 15 parts by weight, there is achieved a further gain in tinctorial strength.

Instead of the coconut oil aminacetate, there may be used with the same result, for example, oleyiaminacetate, tallow fat aminacetate and stearylaminacetate, or even the lactic salts thereof. I

Instead of being added to the alkaline coupling solution, the above-mentioned cationic additives may either be added to the precipitating vinegar or also after precipitation of the coupling component or they may be used together with the tetra-azo solution.

We claim:

1. In a process for preparing water-insoluble azo-dyestufis, the improvement of adding, to a coupling mixture, a surface active salt of a primary aliphatic amine of from 10 to 18 carbon atoms with a carboxylic acid of the group consisting of formic acid, acetic acid, and lactic acid in an amount of from 1 to 10% by weight referred to the final azo-dyestuff.

2. The process as defined in claim 1, wherein the surface active salt is oleylamino acetate.

3. The process as defined in claim 1, wherein the surface active salt is added to the diazo component before coupling.

4. The process as defined in claim 1, wherein the sur face active salt is added to the coupling component before coupling.

5. The process as defined in claim 1, wherein the surface active salt is added to the coupling mixture in the course of the coupling.

Schwartz et al.: Surface-Active Agents and Detergents, vol. II (1958), pp. 103 to 119, TP 149 S3 C7.

Claims (1)

1. IN A PROCESS FOR PREPARING WATER-INSOLUBLE AZO-DYESTUFFS, THE IMPROVEMENT OF ADDING, TO A COUPLING MIXTURE, A SURFACE ACTIVE SALT OF A PRIMARY ALIPHATIC AMINE OF FROM 10 TO 18 CARBON ATOMS WITH A CARBOXYLIC ACID OF THE GROUP CONSISTING OF FORMIC ACID, ACETIC ACID, AND LACTIC ACID IN AN AMOUNT OF FROM 1 TO 10% BY WEIGHT REFERRED TO THE FINAL AZO-DYESTUFF.