FR2610942A1 - LIQUID SULFUR DYE COMPOSITIONS AND THEIR PREPARATION - Google Patents

Abstract

THE INVENTION RELATES TO A LIQUID COLORING COMPOSITION COMPRISING AT LEAST ONE SULFUR COLOR IN LEUCO FORM AND A REDUCING AGENT FOR LEDIT COLORANT WHICH IS CHOSEN FROM A SULFIDE FORM IN SITUATED OR FROM THIONATION AND A REDUCING SUGAR, THE COMPOSITION HAVING A REDUCING SUGAR. TOTAL IN MINERAL SULPHIDES 3 BY WEIGHT IN RELATION TO THE TOTAL WEIGHT OF THE COMPOSITION.

Description

The present invention relates to liquid dye compositions

  sulfur in leuco form. The preparation of sulfur dyes in leuco form involves various stages and invariably, at least one of them causes the formation of one or more salts in the product. For example, sulfuric acid and hydrochloric acid are frequently used in condensation reactions to prepare the intermediate indophenols and also during the precipitation of certain dyes with

  sulfur from solutions obtained after thio-

  nation (sulfurization). Such acids can produce salts by reaction with sodium sulfide and / or sodium hydroxide which is commonly used for the preparation of sulfur dyes. Salts such as sodium sulfide, copper sulfate and sodium chloride are often used during the thionation step which is essential for the preparation of sulfur dyes and also sodium chloride to facilitate the precipitation of the dye. from the solution obtained. In addition, in the preparation of sulfur dyes in leuco form, sodium sulfide is often used as the reducing agent. Other salts, such as sodium thiosulfate, sodium nitrite and sodium thiocyanate, are introduced or produced in either stage of the preparation of the sulfur dyes under

leuco form.

  The Applicant has now found a way

  surprising that liquid compositions can be obtained

  sulfur dyes in leuco form containing a reduced amount of mineral sulfides and also preferably a small amount of all the mineral salts generally resulting from the preparation of

such dyes.

  The invention therefore relates to a liquid dye composition comprising at least one sulfur dye in leuco form and a reducing agent for said dye, which is chosen from a sulphide formed

  in situ or from thionation and a sugar

  conductor, the composition having a total content of mineral sulphides 4 3% by weight relative to the weight

total of the composition.

  The sulphide content of the liquid dye compositions according to the invention is determined according to known analysis techniques, for example

  iodometric method using thio-

  sodium sulfate and refers to the total amount of sodium sulfide and sodium hydrogen sulfide present. According to a preferred method, sodium sulfide and sodium hydrogen sulfide are first

  separated from the dye liquid with acetic acid

  tick according to the usual methods, for example by a stream of carbon dioxide, and are then

  treated with a 0.1N iodine solution and a solution

  0.1N sodium thiosulfate. There are other titration methods for determining the sulfur content; however, it should be noted that some methods interact with the dye at

  sulfur, for example the potentio-

  metric with the 0.2N solution of cupric ammonium sulphate which can give a sulfur content up to 13%. The liquid sulfur dye compositions of the invention preferably have a content of

  mineral sulfides not exceeding 2.5%, more preferably

  between i and 2.5%, in particular between 1.5 and 2.5% relative to the total weight of the composition. Relative to the weight of the sulfur dye in leuco form, the content of mineral sulfides is usually between 0 and 18.5%, in particular between 1

and 14%.

  By sulfur dyes is meant colo-

  known sulfur rants, soluble or insoluble in water, sulfur vat dyes, or mixtures

of these dyes.

  The liquid dye compositions of the invention preferably contain an alkali and,

  as a reducing agent, preferably a reducing sugar

  tor. The invention also relates to a method of

  preparation of such liquid colo compositions

  sulfur rants, process by which a sulfur dye is reduced in an alkaline aqueous medium containing, as a reducing agent for the sulfur dye, a reducing sugar and / or a sulfide formed in

situ or from thionation.

  The alkali used to prepare the alkaline medium is generally a hydroxide, a carbonate or

  an alkali metal phosphate (e.g. pyrophos-

  tetrasodium phate, trisodium phosphate or phos-

  disodium phate), preferably potassium hydroxide or sodium hydroxide, more preferably the latter. The amount of alkali must be sufficient to maintain an alkaline pH, usually between 9 and 14. Preferably enough alkali is used to obtain a pH initially between 10 and 12 and which can drop slightly when a reducing sugar is used , this is due to the transformation of certain reducing sugars into organic acids. The amount of alkali is normally between about 1 and about 17%, in particular between 2 and 13% per

  relative to the total weight of the reaction mixture.

  The aqueous alkaline medium is preferably heated to a temperature between 60 and 110 ° C., more preferably between 70 and 95 ° C., in order to increase

  the activity of the reducing agent. We heat preferably

  until a sufficient amount of the dye is reduced so that at least 90%, preferably at least 95%, more preferably at least 99% by weight of the

dye is dissolved.

  With some sulfur dyes, such as C.I. Sulfur Black 1 and 2, it has been found that sufficient reduction can be achieved without adding

  alkaline medium of any reducing agent.

  The alkali, such as sodium hydroxide, reacts with the sulfide associated with the dye to form, in situ,

  sulfides such as sodium sulfide and hydrogen

  sodium sulfide, which in turn reduces the dye and makes it soluble in an alkaline aqueous medium. As a reducing agent for the colorant

  sulfur, a reducing sugar is preferably used.

  As reducing sugars, any of the sugars or combinations thereof which reduce a Fehling solution can be used, e.g.

  monosaccharides such as aldopentoses such as ara-

  binose, ribose and xylose, hexoses such as glucose, fructose, mannose and galactose, and their deoxy, dideoxy and aminodeoxy derivatives, disaccharides, such as sucrose, lactose,

  maltose and cellobiose, and tri-, tetra- and penta-

  saccharides. Corn syrup, invert sugar and molasses products that contain reducing sugar can also be used, as well as glucose

  prepared in situ from sucrose. Sugar re-

  the conductor is preferably glucose.

  The amount of reducing sugar varies in

  function of the sulfur dye used and its concentration

  tration in the alkaline aqueous medium. The amount must be sufficient to reduce the dye so that it is completely dissolved or miscible at least 90% in the alkaline aqueous medium. Preferably, the amount of reducing sugar is sufficient to assure complete dissolution or miscibility of the dye in the liquid dye composition at any concentration and at any temperature at which the dye composition is capable of being stored. or transported. The amount of suitable reducing sugar is between 1 and 25%, preferably between 4 and 18% relative to the total weight of the reaction mixture. Based on the weight of the dye, the amount of reducing sugar, when used, is usually between 2 and 200%, preferably

  between 8 and 95%, more preferably between 25 and 85%.

  Preferably, no sodium sulfide or other reducing sulfide is added to the aqueous alkaline medium. The reducing sugars are more preferably the only reducing agents which are added during the preparation of the liquid dye compositions at the

  sulfur of the invention. However, due to the inter-

  action of sulfides, which may be present as elemental sulfur or linked to the chromophore of the dye as a polythio group, with the alkali, as indicated above, and / or with the electrons of the oxidation of the reducing agent which takes place during reduction of the dye, a small amount of sulphides may form in situ, for example sodium sulphide or sodium hydrogen sulphide. The amounts of elemental sulfur that may be present in the thionation product can be reduced according to the methods

  known, for example by treating the product of thio-

  nation oxidized by aqueous sodium sulfite to

  dissolve the sulfur, and then filter.

  If necessary, the total content of mineral sulphides in the liquid composition of dyes can be controlled by adjusting the amounts of alkali and particularly reducing sugar in the reaction mixture. The sulfur dyes used in the process of the invention can be any of the dyes obtained according to the conventional thionation method (sulphurization), either directly after the thionation, or after the precipitation process and

  possibly isolation as described below.

  As suitable dyes, mention may be made of the dyes CI Sulfur Black i (n 53 53 185), 2 (n 53 195), 11 (n 53 53 290) and 18, CI Sulfur Green 2 (n 53 531), 16 and 36, CI Vat Blue 43 (n 53 630), CI Sulfur Blue 7 and 13 (n 53 440 and 53 450), CI Sulfur Red 10 (n 53 228) and 14, CI Sulfur Brown 37, 10 (n "53 055), 96, 52 (no 53 320), CI Sulfur Orange 1

  (n053 050) and C.I. Sulfur Yellow 22.

  According to a preferred variant of the invention, the sulfur dye is a dye which has been washed to remove the salts which are generally associated with such thionation products. Another aspect of the process of the invention is therefore the step of washing a sulfur dye with water before introducing it into the aqueous alkaline medium for reduction. The washing water is preferably at a temperature allowing effective removal of the salts without it

  there is dissolution of a significant amount of colo-

  rant, for example at a temperature of 20 to 70 C, more preferably from 30 to 50 C. Washing is carried out

  preferably until the mineral sulphate content

  relative to the weight of solids in the

  filter cake is less than 6%, preferably

  less than 2%, especially less than 0.6%.

  These percentages more preferably represent the maximum percentages of the total of the mineral salts. To determine if the salt content is low enough, samples are taken from the wash water after washing and the electrical conductivity is checked. Washing is continued until a sample of the washing water has a sufficiently low conductivity after washing, that is to say that it is close to or more preferably identical to that of the washing water. wash before washing. For this purpose, a conductivity meter such as the Chemtrix type 700 can be used. By using this device and washing with water having a conductivity between 60 and 80 micromhos / cm, good results are obtained when the washing is carried out. until the used washing water has a conductivity between 60 and 200, preferably between 60 and 120 micromhos / cm. However, with some sulfur dyes which are slightly soluble in water in oxidized form, a somewhat higher conductivity can be obtained, for example up to 400 micromhos, due to the presence in the used washing water. , in addition to mineral salts, a small

amount of dye dissolved.

  Preferably, the sulfur dye is a dye which, in oxidized form, corresponds to the following test: 5.0 g of the filter cake are dispersed in ml of water at room temperature by vibration for 15 minutes in a Fischer apparatus Benchtop Ultrasonic Cleaner. The resulting dispersion is filtered through a Metrical Membrane Filter of 0.45 micron, 47 mm in diameter (from the firm Millipore

  corp.) at n1XX 1004700. The filtrate must be colorless.

  As indicated above, the steps of

  thionation and precipitation, allowing preparation

  tion of the sulfur dyes used in the process of the invention are conventional. For example, the thionation reaction can be carried out according to the method described in the Color Index, volume 4, 3rd edition (1971), pages 4475 & 4501. As clearly follows from this document, a large number of organic compounds can be used as starting materials. The thionating agent is usually sulfur or an alkali metal polysulfide and is preferably used in a minimum amount. The thionation can be carried out by heating or heating at reflux the reaction products in a liquid medium such as water or a lower alcohol, for example ethanol or butanol. If necessary, in particular when the thionation is carried out by heating, the product is dissolved in aqueous sodium sulfide or in caustic soda, preferably at elevated temperatures. The precipitation is carried out by treatment of the thionation product in a medium

  aqueous with a sufficient amount of an oxy-

  dation and optionally an acid or an alkali, to precipitate the dye with sulfur. Any oxidizing agent known to be useful in this field can be used, for example sodium nitrite, hydrogen peroxide, oxygen or air. As suitable acids

  include sulfuric acid and / or chlorine acid

  water. The amount of oxidizing agent and / or acid

  will depend on the nature of the particular thionation product

  of the particular dye prepared and the amount of sulfides present. This quantity

  should preferably be sufficient to make preci-

  completely dip the sulfur dye. When using an alkaline medium, it can contain up to 5%

  by weight of an alkali, as indicated above.

  Preferably, the colo-

  sulfur rants used according to the invention, by oxy-

  donation. The oxidation is carried out more preferably until the oxidation mass is free of sodium sulfide and sodium hydrogen sulfide, which can be determined according to known analysis methods, for example by iodometric titration with a

  sodium thiosulfate solution. The product of thio-

  nation is most preferably diluted with water or concentrated alkali metal hydroxide and treated with air between about 40 and 90 "C until precipitation

complete with dye.

  In some cases it may be advantageous to add a salt such as sodium chloride to cause precipitation of the dye, as indicated

  in the description of the dye C.I. Sulfur Blue 11

  (ne 53235) on page 4487 of the Color Index mentioned above. The precipitated sulfur dye is isolated according to known methods, for example by filtration, and is preferably washed as indicated above. In addition to the sulfur dye in the leuco form, alkali, reducing sugar and water, an agent can be added to the liquid dye composition which further increases the solubility of the dye.

  in leuco form. Once the dye that preci-

  pity has been separated from the residue of the thionation reaction mixture and it has been preferably washed, it is recommended to avoid adding ionic components to the dye. The agent increasing the solubility is therefore advantageously nonionic. For this purpose, the agents

  nonionic hydrotropes are suitable, such as ethyl

  lene glycol, diethylene glycol, polyethylene glycol, C1-C6 alkyl monoethers of diethylene glycol, preferably methyl or ethyl monoethylene of diethylene glycol, C1-C4 alkyl diethers of diethylene glycol, propylene glycol and urea, as well as triethanolamine. The preferred hydrotropic agent is diethylene glycol. The hydrotropic agent is used in

  an amount between about 2 and 35%, usual-

  between 4 and 22% relative to the total weight of the

liquid dye composition.

  The order of addition of the components is not

  determining. All the components, i.e. the colo-

  rant, reducing sugar, alkali, water and possible-

  The solubility enhancing agent can be mixed together and then heated. However, the components other than the reducing sugar are preferably mixed and the mixture is heated to a temperature between 60 and 110 ° C., preferably between 80 and 950 ° C., and the reducing sugar is then added. Heating is continued, preferably under agitation,

  until all components go into solution.

  According to another preferred aspect of the invention

  tion, the reduction according to the invention of the sulfur dye is carried out under an inert atmosphere, for example under nitrogen. Avoiding contact of the liquid dye composition with oxygen increases the efficiency of the reduction and reduces the need for reducing sugar and alkali, thereby allowing higher concentrations of dye in

the final product.

  In some cases it may be necessary to control the reduction conditions in order to avoid the simultaneous production of an excessive amount of sulfides such as sodium sulfide. This may result in a small portion of dye, for example less than 10%, preferably not more than 5% by weight, remaining undissolved. In this case, it is advantageous to subject the liquid dye composition to sulfur in leuco form at a final stage.

  clarification. This can be done by filtra-

  tion of the liquid, preferably when it is still at the same temperature as that at which it was

  performed the reduction, or at a close temperature.

  More preferably, a filtration aid such as diatomaceous earth or activated carbon is added to the liquid composition, with stirring, and filtered. The amount of filter aid can vary widely but is generally between 1 and 12%, preferably between 2 and 6% by weight per

  relative to the weight of the liquid dye composition.

  The preferred liquid compositions of the invention have, in addition to their low content of mineral sulfides, also a low content of mineral salts. Preferably, they contain less than 3%, in particular less than 1.5%, especially less than 0.4%, in particular less than 0.1% by weight of sulphates

  minerals, more preferably less of said percent

  total mineral salts other than sulphides.

  The content of the sulfur dye compositions in leuco form is preferably greater than 8% by weight and is more preferably between 8.5 and 40%, especially between 15 and 36% by weight. The compositions of the invention also contain from 1 to

  %, in particular from 4 to 18% by weight of sugar

  conductor and / or its oxidized derivatives, from 1 to 17%,

  particular from 2 to 13% by weight of hydroxide, carbon

  nate or alkali metal phosphate (or an amount sufficient to give a pH of about 9 to 14), from 22 to%, in particular from 22 to 55% by weight of water and,

  when present, approximately 2 to 35%, in part

  4 to 22% by weight of an agent increasing the solubility. The liquid dye compositions of the invention have many advantages. Their low content of mineral sulphides, for example sodium sulphide, sodium hydrogen sulphide and sodium polysulphides, reduces unpleasant odors, reduces the danger of hydrogen sulphide formation, reduces the need to treat waste water and loss of tensile strength (breaking) of cotton fabrics dyed with black sulfur dyes. Since sulfur dyes have high molecular weights and contain only thiol groups as solubilizing groups, their solubility in water is limited. Therefore, the presence of salt produces a strong release effect on the dye. The low mineral salt content of the compositions of the invention increases their stability during storage and transport. They are stable for at least 24 hours and preferably for more than 48 hours at -6 C. Since the compositions of the invention contain limited amounts of mineral sulphides, it is believed that the low sulphide contents can cause more high stability of these compositions by improving the reducing power

sugar.

  Whereas all the ionic components, except the dye and the necessary quantity of alkali to obtain a satisfactory pH, are either

  greatly reduced or completely eliminated, the formu-

  lation above gives a particular liquid dye composition in which the ionic character of the dye solution is significantly reduced and a nonionic character (or organic liquid) prevails when such a composition is

applied to the fabric.

  Their low salt content also allows the compositions of the invention to have a content

high in color.

  Due to the reduced release tendency, the dyes of these compositions have a

  increased penetration. During the initial penetration phase

  In the exhaustion dyeing process, the dyes are distributed more evenly over the fiber before the addition of salt which causes them to rise on the fiber. This reduces the possibility of precipitation

  premature dye on the fibers, causing

  would be a less good distribution of the dye and a

unwanted tanning effect.

  The compositions of the invention also have a more moderate affinity or substantivity for cellulosic materials. They can therefore be used for the continuous dyeing of cotton and cotton / polyester blends to give

  solid dyes characterized by the absence of different

  shade nuance across the width of the edges-

  center and by the lack of difference in shade in the

  sense of length (tailing effect).

  The liquid dye compositions of the invention can be used for dyeing or printing substrates capable of being dyed with sulfur dyes in leuco form, such as cellulose fibers and their mixtures with other fibers, such as polyester. , according to the usual methods for dyeing and printing with known sulfur dyes (in leuco form), such as those described for example in the Color Index, volume 3, 3rd edition (1971) page 3649. The liquid compositions of dyes of the invention can be used for discontinuous or continuous dyeing as well as for printing, for example dyeing on a beam, with a jigger, on a crossed reel, on a boat, with a jet, by padding-spraying (pad- steam),

  by padding-drying-padding-spraying (pad-dry-

  pad-steam) or padding-drying-thermosolage-

  padding-spraying (pad-dry-thermosol-pad-steam).

  They can be mixed with the dye bath or

  printing paste by simple dilution.

  The amount of liquid composition of colo-

  rants & add to the dye bath or printing paste depends on the dye content of the particular liquid used and the characteristics desired

  dyeing or printing and can be deter-

  undermined by the skilled person. In general, between about 7 and 350, preferably between about 25 and 200 g of liquid dye composition per liter, are added.

dye bath.

  While the amount of reducing agent included in the liquid dye composition during its preparation is usually sufficient to ensure good dissolution of the dye in the dye bath, it is sometimes advantageous to add an additional portion of reducing agent to the bath of dye. Such reducing agents include the compounds commonly used for this purpose, such as sodium sulfide, sodium hydrogen sulfide, sodium polysulfide, sodium hydrosulfite or sodium formaldehyde sulfoxylate. However, the preferred additional reducing agents are the reducing sugars noted above, especially glucose. The quantity of additional reducing agent must be sufficient to ensure complete dissolution of the dye in the dye bath and uniform and reproducible dyes. Man's

  trade can determine the appropriate quantity, depending on

  tion of the particular dye and reducing agent used and the dyeing conditions. The appropriate amount is between 7 and 120 g, preferably

  between 15 and 60 g per liter of dye bath.

  Preferably, with the reducing agent, a portion is also added to the dye bath.

  additional alkali, such as carbonate, hydro-

  xyde or sodium or potassium phosphate, for example an amount between approximately 3.5 and 60,

  preferably between 5 and 30 g per liter.

  The dyeing or printing baths may contain other dyeing aids, for example a wetting agent, in an amount included

  for example between 1.0 and 15 g per liter.

  After the application of the dye, the substrate is subjected to a usual oxidation step in the dyeing with sulfur dyes or sulfur vat dyes. Although some dyes may be sufficiently oxidized by the rinse step

  the water that normally follows dyeing, it is preferred-

  able to carry out chemical oxidation. Suitable oxidizing agents include the combination of hydrogen peroxide and acetic acid or the system

catalyzed with sodium bromate.

  The following examples illustrate the present invention without in any way limiting its scope. In these examples, the parts and percentages are by weight and the temperatures are expressed in degrees Celsius.

Example 1

  In 800 g of water, 382 g of the gross thionation mass of the dye CI Sulfur Blue 13 (CI No. 53450) obtained according to the usual thionation technique are dissolved, and a current is passed to 68 700 air for 6 hours, which causes the dye to completely precipitate. The precipitated dye is filtered and the filter cake is washed at room temperature with running water until a sample of the wash water shows no

  increase in conductivity compared to conductivity

  initial activity of the water used. 349.4 g of filter cake having a solids content are obtained

25.4%. 57 g of the filter cake obtained above are mixed with 18 g of

  diethylene glycol, 10 g of water and 16 g of a 50% solution of sodium hydroxide and the mixture is heated to 800. The mixture is then heated to 850 under a nitrogen atmosphere and gradually added with stirring 11 g glucose. Heating is stopped after 25 minutes. 110.3 g of a stable liquid dye composition are obtained having a sulphide content of

  6.5% (determined by potentiometric titration with a solution

  0.2N cupric ammonium sulfate) and a pH of 6.9.

Example 2

  In 3000 g of water, about 500 400 g of the gross thionation mass of the dye C.I. Sulfur are dissolved.

  Red 10 (CI No. 53228) obtained using the thio- technique

  usual nation, the solution is heated to 70-75 and a stream of air is passed through it at this temperature for 6 hours. The sulphide content of the oxidation mass

  result is equal to 0 (determined by iodome titration -

  with a 0.1N solution of cupric sodium thiosulfate). The precipitated dye is filtered off and the filter cake is washed with running water having a conductivity of about 60 micromhos / cm until the washing water has a conductivity

  about 95 micromhos / cm. The filter cake results

  both weighs 273.5 g and has a solids content of

63.0%.

  44.9 g of the filter cake obtained above are mixed with 30.0 g of diethylene glycol and 23.0 g of a 50% solution of sodium hydroxide and the mixture is heated to 85 under a nitrogen atmosphere, all by gradually adding with stirring 4 g of glucose. After 30 minutes, 2 g of Filter Aid 4200 FW50 (a diatomaceous earth filter aid) are added, the liquid is stirred for 2 minutes and filtered through 11 cm Fischer filter paper. 100 g of a stable liquid composition are obtained

dye having a pH of 11.1.

Example 3

  To a mixture of 180 g of water and 330 g of a

  50% solution of sodium hydroxide is added, in es

  pace 20 minutes and while heating to a temperature of 115-120, 192 g of the gross thionation mass of the dye C.I. Sulfur Yellow 22. We continue to heat for 2 hours at 120, while maintaining at constant volume. The resulting mixture is diluted to 1500 ml with water and 200 g of sodium chloride are added thereto. In the

  resulting mixture maintained at 85, pass a

  rant of air for 58 hours until the sulfur content is equal to 0 and it is then cooled to room temperature. The pH is adjusted to 6.0 by adding 36.4 g of a 75% solution of sulfuric acid and the mixture is stirred

  the resulting mixture overnight at room temperature

  biante. It is then filtered and the wire cake is washed.

  tration with 14 liters of running water at 400 until

  the conductivity of the wash water is 82 micromhos / -

  cm. 666 g of filter cake having a

  solids content of 11.2%.

  Heated to 75 under a nitrogen atmosphere a

  lange of 84 g of the filter cake obtained above and 12 g of a 50% solution of sodium hydroxide. 6 g of glucose are then added and heating is continued at 850 for 30 minutes. The resulting solution is filtered on 11 cm Fisher filter paper, which gives 101.0 g of

  liquid dye composition having a sulfur content

  1.18% fures (determined by potentiometric titration with a 0.2N solution of cupric ammonium sulfate) and

a pH of 11.6.

Example 4

  Stir at room temperature for 30

  minutes, 200 g of the C.I.

  Sulfur Black 2 (CI 53195) in 2 liters of water, then filtered. The filtrate is washed with 16 liters of running water at 500. The final wash water has a conductivity of 300

  micromhos / cm due to the presence of a low quan-

  dye dissolved therein. We obtain

  , 9 g of filter cake having a ma-

solid thirds of 60.1%.

  46.6 g of the filter cake obtained are mixed

  above with 20 g of a 50% aqueous solution of hydro-

  sodium xyde and 15 g of water and the mixture is heated to 900 for minutes under a nitrogen atmosphere. 80 g of a stable liquid dye composition are obtained having a sulphide content of 7.94% (determined by potentiometric titration with a 0.2N solution of cupric ammonium sulphate) and

a pH of 11.4.

Example 5

  In a mixture of 963 g of the mass of thiona-

  tion of the dye CI Sulfur Blue 7 (CI 53440) and 2000 g of water, an air stream is passed to 85 for 14 hours until the sulfur content is equal to 0. The dye is filtered. which has completely precipitated, the filter cake is washed with 3 liters of water at 500 and

  100 g of sodium sulfite are added. We heat the

  lange resulting for 2 hours at 720 to perform additional desulfurization and filtered. We wash the

  filter cake with 10 liters of water at 50. We ob-

  holds 533 g of filter cake having a content of

91.7% solids.

  77 g of the filter cake obtained are mixed

  above with 30 g of diethylene glycol, 25 g of a so-

  aqueous solution at 50% sodium hydroxide and 50 g of water and the mixture is heated to 880 under a nitrogen atmosphere. 20 g of glucose are then added and heating is continued for minutes. 200 g of a liquid dye composition are obtained having a sulphide content of 5.15% (determined by potentiometric titration with a 0.2N solution of

  ammonium sulfate) and a pH of 11.1.

Example 6

  In a mixture of 250 parts of the gross thionation mass of the green sulfur dye prepared according to Example 1 of American Patent No. 3,338,918 and 488 parts of water, a stream of air is passed for 2 hours at 88, then cooled to 45 and filtered. The filter cake is washed with 12,000 parts of running water until the washing water is clear and has a conductivity of 110 micromhos / cm. 55 parts of a filter cake having a content of

43.2% solids.

  6.5 parts of the filter cake are mixed

  obtained above with 2 parts of water, 2 parts of di-

* thylene glycol and 2.2 parts of a 50% solution of hy-

  sodium hydroxide and the mixture is heated to 780 cents

  nitrogen atmosphere. Then 1.2 parts of glu-

  cose and stir the mixture for 30 minutes at 85. The resulting solution is then filtered on filter paper

  Fischer 11 cm, which gives 13.7 parts of a composite

  liquid green dye having a pH of 11.5 and a

  4.2% sulphide content (determined by poten- tial titration

  tiometric with a 0.2N solution of cupric ammonium sulfate).

Example 7

  React to 0-5 78 g of diphenylamine with

  71 g of p-nitrosophenol, which gives the corresponding indophenol

  laying which is reacted to boiling at 110 with 67 g of sodium sulfide at 60% and 100 g of sulfur. In

  1250 g of water, dilute the dye with the resulting blue sulfur

  both (CI Sulfur Blue 13, no. 53,450) with 180 g of a 50% solution of sodium hydroxide and 215 g of glucose and the resulting mixture is heated for 15 minutes to 700. A stable composition of sulfur dye in leuco form, having a sulfur content of

  sodium from 1.5 to 2.5% (determined by iodometric titration).

Example 8

  120 325 g of p-hydroxy-diphyde are reacted

  nylamine with 383 g of 60% sodium sulfide and 490 g of sulfur, which gives a reddish-brown sulfur dye (CI Sulfur Brown 96). The thionation reaction finished,

  770 g of water, 268 g of a 50% solution of hydro-

  sodium xyde and 156 g of glucose, and the metal is heated

  swaddle at 80-85 for 30 minutes; there is a reduction

  total dye. The resulting liquid composition has a sulfide content of 2-3% (determined by iodometric titration).

Example 9

  A mixture of 73.5 g of pphenylenediamine, 43.5 g of m-toluenediamine and 12 g of paminophenol is reacted for 26 hours at 250-300 with 242 g of sulfur, which gives an olive green dye ( CI Sulfur

  Green 16). The dye is dissolved in 366 g of a solution.

  50% sodium hydroxide and desulfurized by passing an air stream through the solution

  until the sodium sulfide content is lower

  less than 2%. After adding, under heating to 80, 110 g of glucose and 163 g of a 50% solution of sodium hydroxide, a liquid composition of the dye is obtained.

  reduced with low sulfur content.

Application example A

  10 g of the liquid colo composition are stirred

  rant prepared according to Example 1 and 50 g of water, until a clear solution is obtained. To this solution are added 10 g of glucose, 4 g of a 50% NaOH solution, g of water and 0.5 g of Penetrant EH (phosphoric ester

  anionic). The resulting mixture is stirred for 5 min.

  nutes and diluted with 133 ml of water.

  The dye solution prepared above is heated to 430 and poured into a dye tank. A previously bleached cotton twill fabric is fouled in the dye solution to an expression level of 70-80%, steam treated for 60 seconds at

  101-1030 and then rinsed with warm running water.

  An oxidizing solution is prepared by adding 7.5 g of a 35% solution of hydrogen peroxide, 7.5 g of glacial acetic acid and enough water to obtain a total volume of 1 liter. This solution is heated to 60, the substrate which has been dyed above is added and stirred for 30 seconds. Then rinse the substrate under hot running water until it is clean and

the dryer.

  Example of application B (The following percentages are given relative to the weight of the textile material) A cotton fabric is introduced into a dye bath containing 1% of a commercial wetting agent, 5% of a 50% solution. % sodium hydroxide, 6% glucose and 4% of the liquid dye composition of the example

  7. The bath ratio is 1:10. We increase the temperature

  scratch off the bath at 90-95 and then add in 3 portions

  and within 15 minutes 20 to 40% sodium sulfate. The dyeing is then continued for 45 minutes at 90-95. The dye bath is then cooled to 70 and the dyed fabric is rinsed until the washing water

be crystal clear.

  An oxidizing solution is prepared by adding 2% of a solution & 35% of hydrogen peroxide and 2% of acetic acid & 80% to enough water to obtain a bath ratio of 1:10. We introduce the fabric in this bath and we

milks for 20 minutes to 50.

  After rinsing, the fabric is soaped for 15 minutes at 80 with 2% of a commercial soaping agent

  based on polyacrylate then rinsed and dried.

26 1 0942

Claims (24)

  1.- A liquid dye composition, character-   terized in that it comprises at least one sulfur dye in leuco form and a reducing agent for said dye which is chosen from a sulphide formed in situ or   from thionation and a reducing sugar, the   sition having a total content of mineral sulfides $ 3% by weight relative to the total weight of the composition, 2.- A composition according to claim 1,   characterized in that the total content of mineral sulfides   between 1 and 2.5% by weight relative to the total weight of the composition.   3.- A composition according to claim 1 or   2, characterized in that it contains an alkali.   4. A composition according to claim 3,   characterized in that the alkali is a hydroxide, a car-   bonate or an alkali metal phosphate.   5.- A composition according to any one of   Claims 1 to 4, characterized in that it contains   more than 8% by weight of colorant sulfur in leuco form.   6. A composition according to claim 5, characterized in that it comprises from 8.5 to 40% by weight   sulfur dye in leuco form.   7. A composition according to claim 5 or 6, characterized in that the content of mineral sulfides is between 0 and 18.5% relative to the weight of the   sulfur dye in leuco form.   8.- A composition according to any one of   Claims 1 to 7, characterized in that the content of   mineral sulfates is less than 3% by weight.   9.- A composition according to any one of   claims i to 8, characterized in that the content   total in mineral salts other than sulfides, is less less than 3% by weight.   10.- A composition according to claim 9, characterized in that it is essentially free of   mineral salts other than sulphides.   11.- A composition according to any one of   Claims 1 to 10, characterized in that it contains 1 & 17% by weight of alkali.   12.- A composition according to any one of   claims 1 to 11, characterized in that it is free of reducing sugars.   13.- A composition according to any one of   Claims 1 to 11, characterized in that it contains   a reducing sugar as a reducing agent.   14.- A composition according to claim 13, characterized in that the reducing sugar is present in an amount between 1 and 25% by weight relative to the total weight of the composition.   15.- A composition according to claim 13, characterized in that it contains from 2 to 200% by weight   reducing sugar relative to the weight of the dye.   16.- A composition according to any one of   claims 13 to 15, characterized in that the sugar   reducing agent is chosen from mono-saccharides, di-,   reducing tri-, tetra- and pentasaccharides.   17. A composition according to claim 16, characterized in that the reducing sugar is chosen from   arabinose, ribose, xylose, glucose, fruc-   tose, mannose, galactose, sucrose, lactose, maltose and cellobiose.   18.- A composition according to any one of   claims 1 to 17, characterized in that it con-   holds a nonionic hydrotropic agent which increases the solubility of the dye in the leuco form present in the composition. 19. A composition according to claim 18, characterized in that it contains from 2 to 35% by weight of nonionic hydrotropic agent.   20.- A process for the preparation of a liquid composition of a sulfur dye in leuco form according to   any one of claims 1 to 19, characterized in   what a sulfur dye is reduced in an alkaline aqueous medium containing, as reducing agent for the sulfur dye, a reducing sugar and / or a sulfide   formed in situ or from thionation.   21. A method according to claim 20, charac-   terized in that it is not added to the alkaline aqueous medium, no reducing sulfide.   22.- A method according to claim 20, charac-   that a reducing sugar is present in the alkaline aqueous medium.   23.- A method according to any one of the res-   Dications 20 to 22, characterized in that the sulfur dye is obtained by oxidizing in an aqueous medium or in an alkaline medium the product obtained by thionation of an organic compound.   24.- A process according to any one of the res-   dications 20 to 23, characterized in that the colo-   rant with sulfur to remove mineral salts, before   adding said dye to the aqueous alkaline medium.   25.- A method according to claim 24, charac-   terized in that the sulfur dye is washed until   that it contains less than 6% of mineral sulfates compared to   weight of the total solids.   26.- The use of liquid compositions of   dyes specified in any one of the claims   1 to 19, for dyeing or printing textile substrates. 27.- Textile substrates, characterized in that   they have been dyed or printed using a composite   dye liquid specified in any of claims 1 to 19.