US2236236A - Direct brown azo dyes and processes of manufacturing the same - Google Patents

Description

l atented Mar. 25, 1941 UNITED STATES PATENT OFFICE DIRECT BROWN AZO DYES AND PROCESSES OF-MANUFACTURING THE SAME No Drawing. Application August 2, 1939, Serial No. 287,902

4 Claims.

This invention relates to direct azo colors suitable for dyeing cotton fibres, and especially to a type of such direct tetrakisazo dyes and to methods of manufacturing the same.

5 Numerous direct azo colors for cotton are known which are in general substantive to other cellulosic fibres, such as regenerated cellulose. The dyeings on cellulose and regenerated cellulose, such as cotton fibres and regenerated cellu- 10 lose rayon fibres have bright shades and moderate fastness to light. When these dyes are applied to cellulosic fibres which are associated with non-cellulosic fibres the non-cellulosic fibres are badly stained. Such staining is im- 5 parted to cellulose acetate fibres and other uncolored and differently colored non-cellulosic fibres. Because of their brightness, low-cost and ease of application, direct azo dyes for cellulosic fibres, such as cellulose and regenerated cellulose 2 are in great demand by the art but it is desirable to provide such dyes that do not have afiinity for or deleteriously stain cellulose acetate fibres so that the cellulosic portions of mixtures which contain cellulose acetate can be dyed without deleteriously staining the cellulose acetate portions, and for other reasons.

It is an object of the present invention to provide improved direct azo dyes for cellulosic fibres 30 which do not have the objectionable property of deleteriously staining associated uncolored or differently colored cellulose acetate fibres. Another object of the invention is to provide meth ods of preparing the improved dyes. Other 5 objects of the invention will be apparent from the following description.

The objects of the invention are. attained in general by providing azo compounds of the type X Y Z w u and dyeing the fibres directly 40 from solutions of these compounds. In the type formula, X represents an aniline, a naphthylamine, an aniline monoor di-sulfonic acid, a naphthylamine monoor di-sulfonic acid, an aniline monoor di-carboxylic acid or a naphthylamine monoor di-carboxylic acid, in which any of the aryl nuclei may be unsubstituted or substituted once or more than once by alkyl, alkoxy, aryl, aralkyl, halogen or nitro; Y is an 50 unsubstituted amino-naphthol mono or (Ii-sulfonic acid; Z is a meta-diamino benzene represented by the formula R: III-H:

HiN 5 wherein at least one of the Rs is hydrogen and the other two are at least one of a group consisting of hydrogen, alkyl, alkoxy and hydroxy and wherein one of the groups R1 and R3 is hydrogen; w is benzidine or tolidine; and u is a coupling component of the group'consisting of hydroxy benzene carboxylic acids and coupling components which are devoid of sulfonic acid groups consisting of phenyl pyrazolones, acetoacetarylides of the benzene and naphthalene series which may be unsubstituted or substituted once or more by alkyl and alkoxy groups and mono-hydroxy benzenes. In the making of these compounds the monazo compound X Y is diazotized'and coupled to Z in a basic medium containing an excess of Z over that which couples with the diazo of X Y. This excess of Z in association with X Y- Z constitutes an undesirable constituent in the mixture and it is deleterious to the final product when it is present in the free state and subsequent couplings are made. The coupling medium containing X Y Z and the excess of Z is treated with an extraneous diazotized arylamine containing at least one sulfonic acid group which couples with the excess of Z and forms combinations which are either removed in subsequent operations or are nondeleterious to the coupling medium and to combinations subsequently to be made. When the excess of the compound Z is thus disposed of by coupling, the compound X Y Z is coupled in basic medium with the diazo of the monazo compound w u. The compound X Y Z+w u is then separated from the mixture.

The invention will be more fully set forth in the following moredetailed description which includes examples that are given as illustrative 5 embodiments of the invention and not as limitations thereof.

' Exam'plei A solution of 24.5. parts b weight. of sodium 59 naphthionate was made in 300 parts by weight of water, 11 parts by weight of hydrochloric acid were added in the form of a 30% solution and the mixture was cooled to 10-l2 C. by adding ice. A 30% solution of sodium nitrite was added to the mixture as fast as the nitrite was absorbed until 6.9 parts have been added. The mixture was diazotized at 15 C. for about forty-five minutes. The final mixture containing a yellow suspended solid was acid to Congo red paper.

A basic solution giving a permanent light test on brilliant yellow paper was made by adding a 30% solution of sodium hydroxide to a slurry composed of 34 parts by weight of the monosodium-salt of Z-amino 8 naphthol 3,6 disulfonic acid in 300 parts by weight of water. This solution was made more basic by'adding- 32 parts by weight of sodium carbonate and was cooled to 0 C. by adding ice.

The first coupling was made by running about 95% of the above described diazo mixture into the basic solution of the sodium salt of Z-amino- 8-naphthol-3,6-disulfonic acid with stirring during 15 to 20 minutes. The balance of the solution was then added to the mixture giving a slight excess of the salt over that required for coupling with all the diazo present. The mixture was then stirred another 15 to 20 minutes whilst maintaining the temperature at 0 to 5 C.

The resulting monazo combination in the mixture is represented by the formula NaO as N=N NH2 NaO S SOaNa The above monazo compound was prepared for diazotization by adding a 30% solution of hydrochloric acid until 27.5 parts of hydrochloric acid had been added and the mixture was cooled to 0 C. by adding ice. The monazo compound was diazotized by adding to the acidified mixture a 30% solution of sodium nitrite until 6.9 parts of sodium nitrite had been added and a slight excess of nitrite was present over that required for diazotization. Diazotization was completed in about one-half hour whilst maintaining the temperature at 0 to 5 C. When completed the excess of nitrous acid was neutralized by adding a small amount of aniline-2,5-disulfonic acid in solution.

The second coupling was made at 0 to 5 C. by adding the above diazo to a basic solution of 1,3-diaminobenzene With agitation of the mixture. The basic solution of the coupling component was made by mixing 11 parts of 1,3- diaminobenzene with parts of water and heating to 50 to 55 C. until complete solution was attained. This solution was then cooled to 0 C. by adding ice and 75 parts of sodium carbonate were added. The mixture containing the cooled diazotized monazo compound described above was slowly added to the cooled basic solution of 1,3-diaminobenzene and coupling was allowed to proceed with vigorous agitation whilst maintaining the temperature at about 0 to 5 C. The coupling medium should give a strong test for alkalinity on brilliant yellow paper and a distinct excess of 1,3-diamino benzene over that required to couple with the monazo compound SOaNa NaO aS- N=N NaOaS The excess of 1,3-diamino benzene was next removed by coupling the excess with diazotized aniline-2,5-disulfonic acid in a medium of regulated pH value as follows:

Firstly, the solution of diazotized aniline2,5- disulfonic acid was made by stirring 7.5 parts of the sulfonic acid in parts of water, cooling to 0 C. with ice, adding 2.15 parts of hydrochloric acid as a 30% solution thereof and then slowly adding a 30% sodium nitrite solution as rapidly as the nitrite was absorbed over a period of about one-quarter hour until a slight excess of nitrite over that required for diazotization was present and the compound was diazotized. The temperature was maintained at 0 to 5 C. Finall the excess of nitrite was removed by adding a small amount of aniline-2,5-disulfonic acid.

The mixture containing the product of the second coupling was now made neutral to brilliant yellow paper and acid to blue litmus paper by adding about 47 parts by weight of hydrochloric acid as a 30% solution thereof, and 12.3 parts of crystalline sodium acetate were dissolved in the mixture. This mixture was then violently agitated and one-half of the above described solution of diazotized aniline-2,5- disulfonic acid was added. At this point the medium gave no test for free 1-3-diaminobenzene when spotted with tetrazo dianisidine but a further addition of the diazo was required. The end point was indicated by the following control test for cellulose acetate stain.

A test sample of about 3 cubic centimeters of the coupling medium was diluted to 50 c. c. with water and 1 c. c. of 2 normal sodium carbonate was added. 4 drops of a solution of para-nitroaniline diazo (.1 mol per liter) were added with stirring and the mixture was heated to 50 C. A 4 inch piece of cellulose acetate skein was added and the mixture was slowly heated to 90 C. After removing the skein and washing, the skein had a heavy pink to red stain. This test was applied after successive subsequent additions of diazotized aniline-2,5-disulfonic acid and small additions of diazotized aniline-2,5-disulfonic acid were made successively until there was no decrease in the depth of the cellulose acetate stain as affected by the last small addition.

In this case one-third of the remaining solution of aniline-2,5-disulfonic diazo was added very slowly over one-quarter hour to the coupling medium. The cellulose acetate stain test was applied and then other small portions of the diazo solution were added with testing for cellulose acetate stain after each addition. This was continued until all the excess of 1-3-diaminobenzene was coupled with diazotized aniline-2,5-disulfonic acid and the last two tests showed like stains.

During the latter additions the coupling medium was repeatedly tested for pH value and was maintained at a pH value of about 5.

After the addition of the last portion of diazotized aniline-2,5-disulfonic acid the coupling mixture was stirred about one-half hour.

The disazo combination contained in the coupling medium was next coupled with the diazotized monazo compound obtained by coupling tetrazotized benzidine with salicylic acid. The coupling medium containing the described disazo combination and with the excess of 1,3-diamino- 'benzene rendered inactive was made basic by adding 22 parts of sodium carbonate and cooled to 01 C. A previously and freshly prepared suspension o-f benzidinesa1icylic acid diazo was cooled'to 0 to 5 C. with stirring until the coupling was completed which required about 5 hours.

The tetrakisazo compound was separated from the coupling medium by heating to C. to 0., adding about 15% by weight of the medium of sodium chloride, stirring 30 to 40 minutes, adding hydrochloric acid until thesolution was acid to litmus and then stirring one-half hour. The dye which was practically all out of solution, was filtered oil and dried at C. .to C. in an oven.

The product was a dark brown powder, soluble in water, giving a deep brown direct dyeing on cotton and rayon. The product is represented by the formula 0 E 17111 NaO3S N=N N=N-ONH2 NaOzS SOaNa I C O ONa The solution of diazotized benzidinesalicylic acid which was used in the final'coupling was prepared as follows. An alkaline solution of sodium salt of salicylic acid was first made by mixing 12.5 parts of salicylic acid in 300 parts of water, adding 3.6 parts of sodium hydroxide and stirring until a clear solution was formed. The solution was then made distinctly basic by adding 9 parts of sodium carbonate. A solution of tetrazotized, benzidine was also prepared as follows. A mixture of 14.8 parts of benzidine hydrochloride and 350 parts of water was made into a slurry,

acid solution was then added to the tetrazo solu-' tion as rapidly as possible and then parts of a sodium carbonate solution containing 11 parts of sodium carbonate per parts of water are added. The mixture was maintained at a temperature of 0 C. to 5 C. and strongly alkaline t brilliant yellow paper until coupling was complete. The couplin was considered complete when a spot test with alkaline 1,8-amino-naphthol-3,6-disulfonic acid solution showed a faint pink. This required about 30 to 40' minutes. There was present a slight excess of salicylic acid as shown by testing with ferric chloride solution.

The dye describedin the foregoing example was dissolved in water in the proportion of 0.25 gram per 200 cubic centimeters of water and heated to F. A 10 g. cotton skein and a 2 g. cellulose acetate skein were tied together and entered into the bath. To 200 c. c. of bath 2 g. of Glaubers salt were added. The bath was heatedto l t- F. and held at this temperature for 45 minutes.

The skeins were removed, washed well in water and dried. The cotton skein was dyed a true deep brown shade whereas the cellulose acetate skein remained practically white.

Another disazo compound was prepared from the same materials as were used for preparing the compound of Example'l. The compound was prepared in exactly the same way as the compound of Example 1 was prepared except that the coupling medium containing the disazo dye was not treated to dispose of the excess of free compound Z. A dyebath made with this compound gave a distinct deleterious brown stain to a cellulose acetate skein.

The invention is further illustrated by the following compounds which were prepared similarly to the compound described in Example 1. These compounds did not harmfully stain cellulose acetate when prepared by the above described method as they did when prepared by the methods disclosed'in the prior art.

Example Combination Shade 2 2-amino-naphthalone-6,8-disulphonic-acid 2-amino-5-naphthol-7-s11lionic acid 1,3-diamino- Brown.

benzene benzidine salicylic acid.

3 aniline-2,5-disulfonic acid 2-amino-8-naphthol-3,ti-disulfonic-acid 1,3-diamino-benzene Do.

benzidine salicylic acid.

4 3methyl-6-methoxy-aniline 2-amino-8-naphthol-3,(i-disulfonic-acid 1,3-diamino-benzene Do.

benzidine salicylic acid.

5 4-chloro-aniline-3-sulfonic-acid Z-amino-B-naphthol-B,fi-dilsufonic-acid 1,3-diamino-benzcne Do.

(- be zidine salicylic acid. I

6 Naphthlonic acid 2-amino-8-naphthol-3,6-d1sulfonic-ac1d 1,3-d1amino-4-methyl-benzene D0.

benzidine salicylic acid. 7

7 l-naphthyllamine1 2amino8-naphthol-3,6-disulfonic-acid 1,3-diam1no-benzene benzidine Do.

) sa lcy 1c aci 8 Naphthionic acid 2-amino-8-naphthol-3,fi-disulionic-acid 1,3-diamino-benzene benzidine Do.

salicylic acid.

9 Naphthionic acid 2-amino-8-naphthol-3,6,disl11f0ni0-ac1d 1,3-diammo-bcnzene ebenzidine Do.

cresotinic-acid.

10.". Nap1hth1ipnic geld 2-amino-5-naphtho1-7-suli'onic-ac1d 1,3-diamino-benzene benzidine Do.

sa my 10 am l1 sulanillic acidi 2-amino-8-naphtho1-3,fi-disulfonic-acid 1,3-diamino-benzene benzidine Do.

s icy 10 am l2 Aniljle 2-amino-8-naphthol-3,6-disulfonic-acid 1,3-diamino-benzene benzidine salicylic Do.

' acl In preparing the compounds of the present invention other diazotized compounds can be used as the extraneous reagent instead of diazotized aniline-2,5-disulfonio acid and to the same effect in removing the excess of uncoupled com-' pound Z from the mixture containing the disazo compound X Y Z. The aniline, 2-, 3- and 4- sulfonic acids, aniline-2,5-disulfonic acids, 1- naphthylamine-iand G-sulfonic acids, l-naphthylamine3,6-disulfonic acids and Z-naphthylamine-6,8-disulfonic acids, any of which are either unsubstituted or are substituted by other groups can be used. In the specification and claims reference to such sulfonic acids means the substituted as well as the unsubstituted acids, unless otherwise denoted. As illustrations of such other compounds are mentioned sulfanilic acid, metanilic acid, 4-ch1oro-aniline-3-sulfonic acid, naphthionic acid, l-amino-naphthalene-6- sulfonic acid, 2-amino-naphthalene-6,8-disulfonic acid, 1-amino-naphthalene-3,6,8-trisulfonic acid, 4-amino-3-methyl-benzene-sulfonicacid, Z-amino 3,5 dimethyl-benzene-sulf0nicacid, 2-aminoi-methyl-5-chloro-benzene-su1- ionic-acid, 2-methoxy-5-amino-benzene-sulfonicacid, 2-amino-5-nitro-benzene-sulfonic-acid, 2- amino-4-nitro-S-methyl-benzene-sulfonic acid, Z-amino -5- methyl-benzene -1,4- disulfonic-acid, 2-bromo-5-amino benzene 1,3 disulfonic-acid and l-amino-Z-methoxy-naphthalene-6-su1fonicacid. In this operation the pH value of the medium is preferably maintained at about 5 but pH values over a range of about 4 to about 9 is generally convenient. However, the extraneous reagent can be used in any acidic or basic medium which is not so acidic as to prevent the coupling with the excess of component Z, and is not so basic as to cause appreciable coupling with the compound X Y Z. The pH value may be adjusted if necessary after each addition of the diazo by adding a base, such as sodium carbonate.

As illustrative of other compounds which can be used for the X component are mentioned 1)- nitro-aniline, para-amino-benzoic acid, aniline-2, 5-carboxylic acid, l-amino-naphthalene-7-carboxylic acid, 2-amino-naphthalene-6,8-dicarboxylic acid and any of the extraneous agents hereinbefore mentioned. These compounds can be unsubstituted or they may be substituted by groups, such as alkyl, alkoxy or halogen.

As other Y compounds l-amino-5-naphthol-7- sulfonic acid, 2-amino-8-naphthol-6-sulfonic acid, and 1-amino-8-naphthol-4,6-disulfonic acid are mentioned as illustrative, but any 1- or 2-arnino-naphthol sulfonic acid can be used as the Y component which has hydroxy in the 5 or 8 position. A second sulfonic acid group may be in any unoccupied position of the ring which is substituted by amino when this component is an amino-naphthol disulfonic acid.

The preferred embodiments of the combination X+Y contains at least two sulfonic acid groups.

As illustrations of other Z compounds ,2-4-diamino-toluene, 2-4-diamino-anisole, 2 6 diamino-toluene, 2,6-diamino -4- methoxy-toluene, 2-4diamino-phenol and 2-methoxy-3,5-diamino toluene are mentioned but any other meta-diamino benzene as indicated by the general formula can be used.

Illustrations of other coupling components, u are 1-phenyl-3-methyl-5-pyrazolone, 1-phenyl-5- pyrazo1one-3-carboxylic acid, aceto-acetanilide, p-methyl-aceto-aoetanilide, alpha-aceto-aceticnaphthanilide, phenol and o-cresol.

'The terms alkyl and alkoxy as used in the specification and claims refer to straight and branched chain aliphatic groups having 1 to 4 carbons and the corresponding alkoxy groups. Aralkyl refers to alkyl-aryl groups of which alkyl is the bridging group and aryl is benzene, such as benzyl. The substituent aryl refers to benzene and naphthalene and halogen refers to chlorine, bromine, iodine and fluorine. The indicated substituents of the aryl nuclei may be substituted in any position or positions which do not interfere with diazotization or coupling.

While some of the improved compounds of the invention give a slight stain on cellulose acetate fibres, the stain is so slight as to be non-deleterious. The invention imparts utility to the dyes which was non-existent in prior art types since the dyes can be used in many combinations of fibres where dyes prepared by prior art methods were unsatisfactory.

From the foregoing disclosure it will be recognized that the invention is susceptible of modification without departing from the spirit and scope thereof and it is to be understood that the invention is not restricted to the specific illustrations herein set forth.

We claim:

1. In the process of manufacturing an azo compound represented by the formula in which X is one of a group consisting of an aniline, a naphthylamine, the monoand disulfonic acids of said anilines and naphthylamines, aniline monoand di-carboxylic acids, naphthylamine monoand di-carboxylic acids, and the derivatives of said compounds of the benzene and naphthalene series in which any aryl nuclei is substituted by at least one of a group consisting of hydrogen, alkyl, alkoxy, aralkyl, halogen and nitro; Y is one of a group consisting of amino-naphthol monoand di-sulfonic acids; Z is a meta-diamino-benzene represented by the formula wherein at least one of the E5 is hydrogen, the other Rs are at least one of a group consisting of hydrogen, alkyl, alkoxy and hydroxy, and wherein one of the groups R1 and R3 is hydrogen; w is one of a group consisting of benzidine and tolidine; and u is one of a group of coupling components consisting of hydroxy benzene carboxylic acids and coupling components which are devoid of sulfonic acid groups from the group consisting of phenyl pyrazolones, aceto-acetarylides of the benzene and naphthalene series, and mono-hydroxy benzenes; the steps which comprise diazotizing a compound X-+Y and coupling with Z in alkaline medium; adding to the coupling medium a diazotized primary arylamine of the benzene and naphthalene series which contains at least one sulfonic acid group, said addition being made until the excess of free compound Z in said mixture is coupled to the added diazo and the medium will give no test for uncoupled compound Z; making the coupling medium basic; and then coupling the compound X Y Z with a diazotized product of coupling w u.

2. In the process of manufacturing an azo compound represented by the formula in which X is one of a group consisting of an aniline, a nap-hthylamine, the monoand disulfonic acids of said anilines andnaphthylamines, aniline monoand di-carboxylic acids, naphthylamine monoand di-carboxylic acids, and the derivatives of said compounds of the benzene and naphthalene series in which any aryl nuclei is substituted by at least one of a group consisting of hydrogen, alkyl, alkoxy, aralkyl, halogen and nitro; Y is one of a group consisting of aminonaphthol monoand di-sulfonic acids; Z is a meta-diamino-benzene represented by the formula i 7 C} I R; Ra

wherein at least one of the Rs is hydrogen, the other Rs are at least one of a group consisting of hydrogen, alkyl, alkoxy, and hydroxy, and wherein one of the groups R1 and Re is hydrogen; w is one of a group consisting of benzidine and tolidine; and u is one of a group of coupling components consisting of hydroxy benzene carboxylic' acids and coupling components which are devoid of sulfonic acid group from the group consisting of phenyl pyrazolones, aceto-acetarylides of the benzene and naphthalene series, and mono-hydroxy benzenes; the steps which comprise diazotizing a compound X Y which contains at least two sulfonic acid groups and coupling with Z in alkaline medium; adding to the coupling medium a diazotized compound of the group consisting of aniline 2-, 3-, and 4-sulfonic acids, aniline 2,5-disulfonic acids, l-naphthylamine-- and -6-sulfonic acids, 1-naphthy1amine-3,6-disulfonic acids and Z-naphthylamine-6,8-disulfonic acids, said addition being made until the excess of free compound Z in said mixture is coupled to the added diazo and the medium will give no test for uncoupled compound Z; making the coupling medium basic; and then coupling the compound X Y Z with a diazotized product of coupling w u.

3. In the process of manufacturing an azo compound represented by the formula in which X is one of a group consisting of an aniline, a naphthylamine, the monoand disulfonic acids of said anilines and naphthylamines, aniline monoand di-carboxylic acids, naphthylamine monoand di-carboxylic acids, and the derivatives of said compounds or the benzene and naphthalene series in which any aryl nuclei is substituted by at least One of a group consisting of hydrogen, alkyl, alkoxy,

aralkyl, halogen and nitro; Y is one of a group consisting of amino-naphthol monoand di-sulfonic acids; Z is a meta-diamino-benzene represented by the formula wherein at least one of the Rs is hydrogen and the other Rs are at least one of a group consisting of hydrogen, alkyl, alkoxy, and hydroxy, and wherein one of the groups R1 and R3 is hydrogen; w is one of a group consisting of benzidine and toli-dine; and u is one of a group of coupling components consisting of hydroxy benzene carboxylic acids and coupling components which are devoid of sulfonic acid groups from the group consisting of phenyl pyrazolones, acetoacetarylides of the benzene and naphthalene series, and mono-hydroxy benzenes; the steps which comprise diazotizing a compound X- Y which contains at least two sulfonic acid groups and coupling Z in alkaline medium containing an excess of Z over that required for coupling; adjusting the coupling medium to a pH value of at least 4 and not more than 9; adding diazotized aniline-2-5-disulfonic acid to the coupling medium until the excess of free compound Z is coupled to the added diazo and the medium will give no test for uncoupled compound Z; making the coupling medium basic; and then coupling the compound X Y Z with a diazotized product of coupling w u.

4. The process which comprises diazotizing the compound represented by the formula HO QNm M,

(JOONa EIVIMET 1". HITCH. SWANIE S ROSSANDER. CHILES E. SPARKS.