USRE22983E - Manufacture of dyestuffs - Google Patents

Manufacture of dyestuffs Download PDF

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USRE22983E
USRE22983E US22983DE USRE22983E US RE22983 E USRE22983 E US RE22983E US 22983D E US22983D E US 22983DE US RE22983 E USRE22983 E US RE22983E
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azobenzene
methylbenzthiazyl
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B49/00—Sulfur dyes
    • C09B49/06—Sulfur dyes from azines, oxazines, thiazines or thiazoles

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  • the present invention relates to the manufacture of dyestuils and intermediates therefor.
  • the invention also comprises the step of hydrolysing a dixanthatoor dithiocyano-p:p-di- (fi-methylbenzthiazyl) azobenzene obtained in the above manner, to the corresponding dimercaptop:p'-d1-(6 methylbenzthiazyl) azobenzene and oxidising the latter to the corresponding polydisulphide.
  • the present polydisulphides represent sulphurc-ontaining dyestufis which may be applied to cellulosic material from sodium sulphide according to the usual practice with sulphur dyestufis. By this means there are obtained bright orange-yellow shades possessing excellent fastness to severe washing, chemick and light.
  • the dixanthato and dithiocyano derivatives of p:p'-di-(6 methylbenzthiazyl) azobenzene referred to above not only constitute intermediates in the described manufacture of sulphur-containing dyestuffs, but may themselves be applied to cellulosic material from sodium sulphide solution according to the usual practice with sulphur dyestufi's.
  • the dixanthato and dithiocyano derivatives become hydrolysed in the sodium sulphide solution to the corresponding dimercapto derivatives. The latter subsequently become oxidised to polydisulphides on the fibre.
  • this invention is to be regarded as relating not only to the manufacture by the aforesaid processes of sulphur-containing dyestuffs in substance, but also to their production on the fibre, that is on the cellulosic material directly, by employing in the technique usual in dyeing with sulphur dyestuffs, the above intermediate products, namely the dixanthato and dithiocyano derivatives of p:p-di-(6-methylbenzthiazyl) azobenzene.
  • the starting material which is a diamino p:p' di-(fi-methylbenzthiazyl) azobenzene is made either (a) by oxidising nitro-dehydrothio-pto1uidine (nitro 6 methyl-Z-p-aminophenylbenzthiazole see German specification No. 81,711) for example, in solution in ethylene glycol monoethyl ether with sodium hypochlorite, and reducing the resulting dinitro-p :p-di- (G-methylbenzthiazyl) azobenzene with e. g.
  • alkyl xanthate (also tobe referred to as alkyl xanthogenate or alkoxy dithioformate) I mean a salt of an alkyl derivative of xanthic or xanthegenic acid, for example, the ethyl derivative. The latter itself is often called more briefly xanthic or xanthogenic acid.
  • I may employ, for instance, as alkyl xanthate, potassium ethyl xanthate or xanthogenate or potassium isopropylxanthate.
  • an alkali metal thiocyanate there may be used in accordance with the invention, for example, sodium or potassium thiccyanate.
  • Example 1 16 parts of diamino-p1p-di-(6-methylbenzthiazyDazobenzene (made as described below) are dissolved in 230 parts of concentrated sulphuric acid at 29 C. A solution of 4.8 parts of sodium nitrite in parts of concentrated sulphuric acid is added and the mixture stirred at 20 C. for hour. The resulting solution is now poured on to 950 parts of a mixture of ice and Water, 10 parts of sodium thiocyanate dissolved in the minimum quantity of water are added and the mixture is stirred and heated up to C. during hour. The temperature is maintained at 80-90 C. for a further hour. The yellow product in suspension is then filtered ofi and washed free from acid.
  • the dithiocyano-p p -di- (6 -methylbenzthiazyl) azobenzene so obtained forms a yeilow powder which is insoluble in water but dissolves in sulphuric acid with a red color. It may be used to dye cotton in a similar manner to the polydisulphide described below.
  • the above dithiocyano-p:p'-di- (6-methylbenzthiazyl) azobenzene is dissolved in e00 parts of alcohol containing 40 parts of sodium sulphide (crystals). The solution is boiled for hour and diluted with 600 parts of water. The dithic cyano compound becomes thereby hydrolysed to the corresponding dimercapto compound. 209 parts of sodium chloride are added and the also hol is then distilled ofi. An orange yellow preclpitate consisting of polydisulphide separates. The latter is formed by oxidation of the mercapto compound by dissolved atmospheric oxygen. The precipitate is filtered ofi and dried in air.
  • the diamino-p :p'-di- (6-methylbenzthiazy1) azobenzene employed above is made as follows. 20 parts of nitrodehydro-p-toluidine are dissolved in 700 parts of boiling ethylene glycol monoethyl ether. The solution is cooled to 40 C. and 100 parts of sodium hypochlorite solution (13% available chlorine) are slowly added with good agitation at 40-45 C. The yellowish brown precipitate of dinitro-p :p'-di- (G-methylbenzthiazyl) azobenzene is filtered off, washed with alcohol and dried.
  • the said dinitro compound is then stirred up with 600 parts of water containing 120 parts of sodium sulphide (crystals) and boiled for 2 hours.
  • the product in suspension is filtered off, washed with water and then with alcohol and dried to a brown powder consisting of diaminopzp' di (6 methylbenzthiazyl)azobenzene.
  • This compound is insoluble in water and mineral acids but dissolves in concentrated sulphuric acid to a red solution.
  • Example 2 3.3 parts of diamino-p:p-di-(6-methylbenzthiazyl) azobenzene (made as described in Example 1) (in the form of a 6.64% aqueous paste) and 110 parts of 10% aqueous sodium nitrite are cooled to 5 C. and added slowly with stirring to 50 parts of 36% hydrochloric acid at C. The temperature is maintained at 0 C. during the addition. The mixture is stirred at 0 C. for A1. hour and poured into an equal volume of a mixture of ice and water. The diazonium compound in suspension is now added slowly with good stirring to a solution of 10 parts of potassium ethyl xanthate and 20 parts of sodium carbonate in 200 parts of water at 60 C.
  • the above product (dixanthato-p:p'-(S-methylbenzthiazyl) azobenzene) is hydrolysed by boiling with 50 parts of alcohol and 5 parts of sodium sulphide (crystals) for hour.
  • the resulting brown solution of dimercapto-p:p'-di-(6- methylbenzthiazyl) azobenzene is diluted with 200 parts of water and filtered from a trace of insoluble material.
  • the solution is then boiled and the aforesaid dimercapto compound oxidised, by the addition of sodium m-nitrobenzene sulphohate, to give the corresponding polydisulphide.
  • Both the dixanthato compound and the polydisulphide derived from it dye cotton in yellowish orange shades from boiling aqueous sodium sulphide solutions.
  • the shades so-obtained possess very good fastness properties particularly in respect of severe washing and chemick.
  • Example 3 3.3 parts of diamino-p:p'-di- (G-methylbenzthiazyl) azobenzene (made as described in Example l) are diazotised with 11 parts of 10% aqueous sodium nitrite'as described in Example 2. The suspension of the diazonium compound soobtained is added slowly with stirring to a solution of 10 parts of potassium isopropyl xanthate and 20 parts of sodium carbonate in 200 parts of water at 60 C. Sodium carbonate is added as needed to keep the solution alkaline to Brilliant Yellow paper. The suspension is stirred at room temperature for 1 hour and then at C. for 4 hour.
  • the precipitate (di-isopropylxanthatop:p-di-(6-methylbenzthiazyl) azobenzene is fil tered off, washed with water and acetone and dried at 80 C. It is a brown powder soluble in boiling dilute sodium sulphide solution.
  • the above diisopropylxanthato compound is boiled with 50 parts of alcohol and 5 parts of sodium sulphide (crystals) for hour.
  • the resulting brown solution of the corresponding dimercapto compound is diluted with 200 parts of water, and oxidised with sodium m-nitrobenzene sulphonate and the polydisulphide isolated in the manner described in Example 2.
  • Example 4 4.15 parts of diamino-p:p'-di-(6-methylbenzthiazyl) azobenzene (made as described below) in the form of an 8.3% aqueous paste are diazotised with 10% aqueous sodium nitrite as described in Example 1 and the mixture then diluted with an equal volume of a mixture of ice and water. 10 parts of sodium thiocyanate dissolved in 10 parts of water are added and the mixture is stirred at 80 C. for half an hour and at 80-90 C. for a further half hour. The brownish yellow precipitate of dithiocyano-p:p'-di-(6- methylbenzthiazyl)azobenzene is filtered '05 and washed with water until free from acid. It dyes cotton in yellow shades from aqueous sodium sulphide solution, the shades having excellent fastness to washing and chemick.
  • the diamino-p:p-di- (G-methylbenzthiazyl) azobenzene employed above is made as follows: 9.7 parts of ptpf-di-(S-methyibenzthiazyl)azobenzene are dissolved in 55 parts of sulphuric acid (monohydrate) at 25-30 C. and 6.8 parts of potassium nitrate added slowlyin small quantities, the temperature being maintained at 25-30" C. After stirring for 2 hours the temperature is raised to 60-65 C. and maintained for 2 hours. The solution is then poured onto ice and the precipitated dinitro' compound filtered off andwashed with water.
  • the so-obtained dinitrop:p'-di- (B-methylbenzthiazyl) azobenzene is reduced to the corresponding diamino compound by boiling with 300 parts of water and '60 parts of sodium sulphide (crystals) for 2 hours. When cool the brown product in suspension is filtered off, washed well with water and dried.
  • Example 5 4.15 parts of diamino-p:p'-di-(G-methylbenzthiazyl) azobenzene made as in Example 4 in the form of an 8.3% aqueous paste are diazotised with 11 parts of aqueous sodium nitrite as described in Example 2. The mixture is diluted with an equal volume of a mixture of ice and water and added slowly with stirring to a solution of 10 parts of potassium ethyl xanthate and parts of sodium carbonate in 200 parts of water at 60 C. Sodium carbonate is added as needed to keep the mixture alkaline to Brilliant Yellow paper. After stirring for 1 hour, the suspension is heated at 70 C. for 10 minutes, filtered and washed with water.
  • the product (dixanthatoin which X is one of a group consisting of thincyano and alkali-metal alkyl-xanthato, with sodium sulfide and water in an inert liquid organic 10 wherein X is alkali-metal isopropyl-xanthato.

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Description

Reissued Mar. 9, 1948 MANUFACTURE OF DYESTUFFS Norman Hulton Haddock, Blackley, Manchester,
England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Original No. 2,368,658, dated February 6, 1945, Serial No. 443,670, May 19, 1942. Application for reissue September 17, 1947, Serial No. 774,663. In Great Britain May 23, 1941 8 Claims. 1
The present invention relates to the manufacture of dyestuils and intermediates therefor.
According to the invention I tetrazotise a diamino-p p'- di- (fi-methylbenzthiazyl) azobenzene which has been made as described below, and cause the resulting tetrazo compound to react with an alkyl xanthate or an alkali metal thiccyanate, thereby obtaining the corresponding dixanthatoor dithiocyano-p:p'-di-(6-methylbenzthiazyl) azobenzene.
The invention also comprises the step of hydrolysing a dixanthatoor dithiocyano-p:p-di- (fi-methylbenzthiazyl) azobenzene obtained in the above manner, to the corresponding dimercaptop:p'-d1-(6 methylbenzthiazyl) azobenzene and oxidising the latter to the corresponding polydisulphide.
The present polydisulphides represent sulphurc-ontaining dyestufis which may be applied to cellulosic material from sodium sulphide according to the usual practice with sulphur dyestufis. By this means there are obtained bright orange-yellow shades possessing excellent fastness to severe washing, chemick and light.
The dixanthato and dithiocyano derivatives of p:p'-di-(6 methylbenzthiazyl) azobenzene referred to above, not only constitute intermediates in the described manufacture of sulphur-containing dyestuffs, but may themselves be applied to cellulosic material from sodium sulphide solution according to the usual practice with sulphur dyestufi's. By this procedure the dixanthato and dithiocyano derivatives become hydrolysed in the sodium sulphide solution to the corresponding dimercapto derivatives. The latter subsequently become oxidised to polydisulphides on the fibre. Thus by the dyeing technique commonly employed with sulphur dyestuifs there are produced on the fibre the same sulphur dyestulis, to the production in substance of which the above-men tioned processes relate. In this way also, dyeings are obtained having the properties already described.
Accordlngly, this invention is to be regarded as relating not only to the manufacture by the aforesaid processes of sulphur-containing dyestuffs in substance, but also to their production on the fibre, that is on the cellulosic material directly, by employing in the technique usual in dyeing with sulphur dyestuffs, the above intermediate products, namely the dixanthato and dithiocyano derivatives of p:p-di-(6-methylbenzthiazyl) azobenzene.
The starting material which is a diamino p:p' di-(fi-methylbenzthiazyl) azobenzene, is made either (a) by oxidising nitro-dehydrothio-pto1uidine (nitro 6 methyl-Z-p-aminophenylbenzthiazole see German specification No. 81,711) for example, in solution in ethylene glycol monoethyl ether with sodium hypochlorite, and reducing the resulting dinitro-p :p-di- (G-methylbenzthiazyl) azobenzene with e. g. sodium sulphide, or (b) by nitrating p p -di- (ii-methylbenzthiazyl) 'azobenzene, obtained by the oxidation of dehydrothio-ptoluidine, and reducing the dinitro-p:p'-di-(6- methylbenzthiazyl) azobenzene thus obtained.
By alkyl xanthate (also tobe referred to as alkyl xanthogenate or alkoxy dithioformate) I mean a salt of an alkyl derivative of xanthic or xanthegenic acid, for example, the ethyl derivative. The latter itself is often called more briefly xanthic or xanthogenic acid. Thus, I may employ, for instance, as alkyl xanthate, potassium ethyl xanthate or xanthogenate or potassium isopropylxanthate. As an alkali metal thiocyanate there may be used in accordance with the invention, for example, sodium or potassium thiccyanate.
The following examples in which the parts are by weight illustrate but do not limit the invention.
Example 1 16 parts of diamino-p1p-di-(6-methylbenzthiazyDazobenzene (made as described below) are dissolved in 230 parts of concentrated sulphuric acid at 29 C. A solution of 4.8 parts of sodium nitrite in parts of concentrated sulphuric acid is added and the mixture stirred at 20 C. for hour. The resulting solution is now poured on to 950 parts of a mixture of ice and Water, 10 parts of sodium thiocyanate dissolved in the minimum quantity of water are added and the mixture is stirred and heated up to C. during hour. The temperature is maintained at 80-90 C. for a further hour. The yellow product in suspension is then filtered ofi and washed free from acid. When dry, the dithiocyano-p p -di- (6 -methylbenzthiazyl) azobenzene so obtained forms a yeilow powder which is insoluble in water but dissolves in sulphuric acid with a red color. It may be used to dye cotton in a similar manner to the polydisulphide described below.
The above dithiocyano-p:p'-di- (6-methylbenzthiazyl) azobenzene is dissolved in e00 parts of alcohol containing 40 parts of sodium sulphide (crystals). The solution is boiled for hour and diluted with 600 parts of water. The dithic cyano compound becomes thereby hydrolysed to the corresponding dimercapto compound. 209 parts of sodium chloride are added and the also hol is then distilled ofi. An orange yellow preclpitate consisting of polydisulphide separates. The latter is formed by oxidation of the mercapto compound by dissolved atmospheric oxygen. The precipitate is filtered ofi and dried in air. It forms an orange-yellow powder which is insoluble in water but dissolves in aqueous sodium sulphide, preferably containing a little alcohol or glycerol, to yield a yellowish brown solution. Cotton is dyed by this solution in shades which, after exposure to the air, are bright orange yellow and possess excellent fastness to severe washing, chemick and light.
The diamino-p :p'-di- (6-methylbenzthiazy1) azobenzene employed above, is made as follows. 20 parts of nitrodehydro-p-toluidine are dissolved in 700 parts of boiling ethylene glycol monoethyl ether. The solution is cooled to 40 C. and 100 parts of sodium hypochlorite solution (13% available chlorine) are slowly added with good agitation at 40-45 C. The yellowish brown precipitate of dinitro-p :p'-di- (G-methylbenzthiazyl) azobenzene is filtered off, washed with alcohol and dried. The said dinitro compound is then stirred up with 600 parts of water containing 120 parts of sodium sulphide (crystals) and boiled for 2 hours. The product in suspension is filtered off, washed with water and then with alcohol and dried to a brown powder consisting of diaminopzp' di (6 methylbenzthiazyl)azobenzene. This compound is insoluble in water and mineral acids but dissolves in concentrated sulphuric acid to a red solution.
Example 2 3.3 parts of diamino-p:p-di-(6-methylbenzthiazyl) azobenzene (made as described in Example 1) (in the form of a 6.64% aqueous paste) and 110 parts of 10% aqueous sodium nitrite are cooled to 5 C. and added slowly with stirring to 50 parts of 36% hydrochloric acid at C. The temperature is maintained at 0 C. during the addition. The mixture is stirred at 0 C. for A1. hour and poured into an equal volume of a mixture of ice and water. The diazonium compound in suspension is now added slowly with good stirring to a solution of 10 parts of potassium ethyl xanthate and 20 parts of sodium carbonate in 200 parts of water at 60 C. During the addition, further amounts of sodium carbonate are added as needed in order to keep the solution alkaline to Brilliant Yellow paper. The suspension is stirred at room temperature for 1 hour and then at 80 C. for hour. The precipitate is filtered ,ofi', washed with water and acetone and dried at 80 C. It is a brown powder soluble in dilute sodium sulphide solution.
The above product (dixanthato-p:p'-(S-methylbenzthiazyl) azobenzene) is hydrolysed by boiling with 50 parts of alcohol and 5 parts of sodium sulphide (crystals) for hour. The resulting brown solution of dimercapto-p:p'-di-(6- methylbenzthiazyl) azobenzene is diluted with 200 parts of water and filtered from a trace of insoluble material. The solution is then boiled and the aforesaid dimercapto compound oxidised, by the addition of sodium m-nitrobenzene sulphohate, to give the corresponding polydisulphide. The latter is thrown down as a brown precipitate, the remaining liquor, when sufiicient sodium m-nitrobenzene has been added to complete the oxidation, having turned from brown to pale yellow. (The color of the liquor is conveniently seen by spotting on filter paper and examining the runout.) The brown precipitate is then filtered off and washed with water.
Both the dixanthato compound and the polydisulphide derived from it dye cotton in yellowish orange shades from boiling aqueous sodium sulphide solutions. The shades so-obtained possess very good fastness properties particularly in respect of severe washing and chemick.
Example 3 3.3 parts of diamino-p:p'-di- (G-methylbenzthiazyl) azobenzene (made as described in Example l) are diazotised with 11 parts of 10% aqueous sodium nitrite'as described in Example 2. The suspension of the diazonium compound soobtained is added slowly with stirring to a solution of 10 parts of potassium isopropyl xanthate and 20 parts of sodium carbonate in 200 parts of water at 60 C. Sodium carbonate is added as needed to keep the solution alkaline to Brilliant Yellow paper. The suspension is stirred at room temperature for 1 hour and then at C. for 4 hour. The precipitate (di-isopropylxanthatop:p-di-(6-methylbenzthiazyl) azobenzene is fil tered off, washed with water and acetone and dried at 80 C. It is a brown powder soluble in boiling dilute sodium sulphide solution.
The above diisopropylxanthato compound is boiled with 50 parts of alcohol and 5 parts of sodium sulphide (crystals) for hour. The resulting brown solution of the corresponding dimercapto compound is diluted with 200 parts of water, and oxidised with sodium m-nitrobenzene sulphonate and the polydisulphide isolated in the manner described in Example 2.
Both the diisopropylxanthato compound and the polydisulphide dye cotton in yellow shades from sodium sulphide solutions, of very good fastness properties.
Example 4 4.15 parts of diamino-p:p'-di-(6-methylbenzthiazyl) azobenzene (made as described below) in the form of an 8.3% aqueous paste are diazotised with 10% aqueous sodium nitrite as described in Example 1 and the mixture then diluted with an equal volume of a mixture of ice and water. 10 parts of sodium thiocyanate dissolved in 10 parts of water are added and the mixture is stirred at 80 C. for half an hour and at 80-90 C. for a further half hour. The brownish yellow precipitate of dithiocyano-p:p'-di-(6- methylbenzthiazyl)azobenzene is filtered '05 and washed with water until free from acid. It dyes cotton in yellow shades from aqueous sodium sulphide solution, the shades having excellent fastness to washing and chemick.
The diamino-p:p-di- (G-methylbenzthiazyl) azobenzene employed above is made as follows: 9.7 parts of ptpf-di-(S-methyibenzthiazyl)azobenzene are dissolved in 55 parts of sulphuric acid (monohydrate) at 25-30 C. and 6.8 parts of potassium nitrate added slowlyin small quantities, the temperature being maintained at 25-30" C. After stirring for 2 hours the temperature is raised to 60-65 C. and maintained for 2 hours. The solution is then poured onto ice and the precipitated dinitro' compound filtered off andwashed with water. The so-obtained dinitrop:p'-di- (B-methylbenzthiazyl) azobenzene is reduced to the corresponding diamino compound by boiling with 300 parts of water and '60 parts of sodium sulphide (crystals) for 2 hours. When cool the brown product in suspension is filtered off, washed well with water and dried.
Example 5 4.15 parts of diamino-p:p'-di-(G-methylbenzthiazyl) azobenzene made as in Example 4 in the form of an 8.3% aqueous paste are diazotised with 11 parts of aqueous sodium nitrite as described in Example 2. The mixtureis diluted with an equal volume of a mixture of ice and water and added slowly with stirring to a solution of 10 parts of potassium ethyl xanthate and parts of sodium carbonate in 200 parts of water at 60 C. Sodium carbonate is added as needed to keep the mixture alkaline to Brilliant Yellow paper. After stirring for 1 hour, the suspension is heated at 70 C. for 10 minutes, filtered and washed with water. The product (dixanthatoin which X is one of a group consisting of thincyano and alkali-metal alkyl-xanthato, with sodium sulfide and water in an inert liquid organic 10 wherein X is alkali-metal isopropyl-xanthato.
5. The process of making sulfur dyes which comprises heating a symmetrical compound represented by the formula in which X is one of a group consisting of thio- 20 cyano and alkali-metal alkyl-xanthato wherein pound in aqueous medium with an oxidizing agent until the corresponding polydisulfide is formed.
6. The process in accordance with claim 5 in which the organic solvent is alcohol.
'7. The process in accordance with claim 5 in which oxygen is the oxidizing agent.
8. The process in accordance with claim 5 in CHI 40 which m-nitrobenzene sulfonate is the oxidizing agent.
NORMAN HULTON HADDOCK.
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