US2067927A - Art of dyeing with vat dyes - Google Patents

Description

Patented Jan. 19, 1937 UNlTED STATES 2,067,927 ART OF Drama WITH VAT mYEs Jean G. Kern, Hamburg, N. Y., assignor to National Aniline & Chemical Company, Inc., New York, N. Y., a corporation of New York No Drawing. Application April 8, 1935, Serial No. 15,260. In Japan September 3, 1934 25 Claims.

This invention relates to the art of dyeing and to dyeing compositions and their application to textile fibers. It relates especially to a new class of assistants for the dyeing of textile fibers and especially those of the vegetable type such as cotton, regeneratedcellulose and the like, with vat dyes by a process in which a leuco compound of a vat dye is formed by the reduction of a vat dye in the presence of the fiber to be dyed, as for example a printing process or a pad-jig dyeing process.

As is well known, vat dyes are solid substances which are insoluble in water. them useful in the dyeing of textile fibers they are converted to a water soluble form, in which form they are taken up by the fiber, and then the fiber is subjected to an oxidizing or fixing treatment whereby'the vat dyestufi' is again rendered insoluble! One general method of application of vat dyes to the dyeing of textile fibers involves application of the ,dye in the unreduced iorm to the material to be dyed,- subjecting the resulting material to a reducing treatment whereby the dye is converted to the soluble form in the presence of the fiber and is taken up by the fiber, and then subjecting it to oxidation and/or other finishing treatments to fix the dye on the fiber and complete the finishing of the material. In dyeing with vat dyes by this general method one of two procedures is usually followed, it depending upon whether the textile material is to be dyed a uniform or so-lcalledsolid color, or is to be dyed in accordance with a pattern or design in one or more colors. ,If the material is to be dyed a solid color, the so-called pigment padding or pad-jig process may be employed. If the material is to be dyed in accordance with a pattern or design, the so-called printing process is generally utilized.

The pad-jig process of dyeing with vat dyes generally involves passing the textile material to be dyed through an aqueous suspension or socalled padding bath containing the unreduced vat dye in finely divided form suspended in a suitable suspension medium (such as water, which may or may not also contain a gum or thickener and other substances, such as an assistant, sodium sulfide, disodium phosphate, etc.) whereby the fiber mechanically picks up the particles of insoluble dye; subsequently working the textile material having the particles of dye mechanically attached thereto, in a reducing bath whereby the dye is reduced to the soluble form and is taken up (absorbed and/or adsorbed) by the fiber; and.

finally subjecting the material to oxidation and In order to render ble gums or thickener's.

finishing treatments to reconvert the dye to the insoluble form and fix it on the fiber, and further complete the finishing of the material. I

The printing process of dyeing textile fabrics generally involves applying a so-called printing paste to the fabric in the form of a design (for example, by means of a screen, a stencil or an engraved roll), and then subjecting the printed general, vat dye printing pastes contain, in addition to the unreduced vat dye, substances which mote the reduction of the dye and/or absorption of the reduced compound by the fiber, and suita- In some cases, as in printing with diflicultly reducible vat dyes, the vat dye in the printing paste is subjected to a preliminary. partial reduction before applying the printing paste to the fabric. The fixing treatment usually comprises subjecting the printed fabric to a short treatment with wet steam while excluding air (so-called steaming or aging) whereby the vat dye is reduced (for example, by the action of the sodium-formaldehyde-sulfoxylate and potassium carbonate), or its reduction is rendered more complete, and the reduced dye is taken up by the fiber, and then subjecting the fabric to oxidizing; washing and other finishing treatments.

Vat dyes, when applied to fabric by a padding process or when printed on fabrics with the aidfabric to further treatment to fix the dye. In

to improper fixation of the dye on the fiber because of variable aging conditions or variable physical conditions of the vat dye padding liquors or printing paste.

Various assistants heretofore have been proposed with the object of improving the dyeings obtained with vat dyes by pad-jig and printing processes but they are all subject to various disciently soluble in water, and especially in printing pastes, to yield good homogeneity, and they impair the good working properties of vat dyestuff printing pastes.- In general the assistants heretofore proposed further sufier from the fact that they produce little or no improvement in prints of light shades.

The use of dispersing agents has also been proposed in the dyeing with vat dyes by the pad-jig process, but they are open to the objection that they act mainly during the padding operation and do not assist in the absorption or adsorption of the leuco compound of the vat dye in the reducing or jigging step.

The present invention is based upon the discovery that the soluble salts of the acid reaction products resulting from the interaction of an aliphatic alcohol containing less than 6 carbon atoms with a polybasic inorganic acid or suitable derivative thereof possess a combination of properties which render them of particular value for use as assistants in the dyeing of textile fibers, and especially those of the vegetable type, such as cotton, rayon (regenerated cellulose) and the like, by a process in which a leuco compound of a vat dye is formed by reduction in the presence of the fiber to be dyed, and especially by pad-jig and printing processes, as well as in the preparation of printing pastes and padding liquors for dyeing textile fibers with vat dyes. Thus the soluble salts of the acid reaction products of sulfuric acid or chlorsulfonic acid upon the aliphatic monohydric alcohols which contain 5 or less carbon atoms, which products are considered to be acid alkyl sulfates corresponding with the formula ROSO3H (in which R is a hydrocarbon radical containing not more than 5 carbon atoms), as well as others of the hereinafterdescribed soluble'salts of acid alkyl esters of inorganic polybasic acids, have the faculty of rapidly entering into solution in water and other aqueous suspension media usually employed in dyeing with vat dyes. They furthermore have no tendency to cause the pastes to foam or lather. In addition they act as assistants in the absorption or adsorption of the reduced compounds of the vat dyes by the fiber, and in the penetration of woven fabric by the reduced compounds of the vat dyes during the developing, steaming or aging operations.

While most of the known vat dye printing assistants exert a very definite action, for example catalytic, dissolving, or enolyzing, on the vat dye, the alkyl ester salts of the present invention apparently act on both the vat dye and the fiber itself, causing more effective absorption of the leuco-compound of the dyestuff and greatly increasing the printing strength of printing pastes.

Although I do not wish to'be limited to any theory of reaction involved in using the assistants of the present invention, it is possible that the alkyl sulfates referred to are partially saponified by the alkaline reagents present in the printing paste so that during the aging operation these materials are slowly acted upon to liberate the corresponding alcohol, and that therefore the alkyl sulfates behave not only as sulfates but as alcohols, serving to more efiectively dissolve or disperse the leuco form of the vat dyestuff. This is further borne out by the fact that other materials which are capable of saponification to produce free alcohols such as the acid alkyl phos- .phates, phosphites, boro-sulfates, boro-.phosphates, borates and silicates, also yield improved results in pad-jig dyeing and printing with vat dyes.

The acid alkyl esters, the soluble salts of which may be employed in accordance with the present invention, include the partial esters of polybasic inorganic acids (as for example, of sulfuric, phosphoric, boro-sulfuric,bore-phosphoric, boric, silicic, etc., acids) and especially those of sulfuric and phosphoric acids containing at least one aliphatic hydrocarbon radical (straightchain, branched-chain, saturated or unsaturated) which contains not more than 5 carbon atoms, as the organic (ester) radical or radicals. These partial esters (which are herein designated as acid alkyl esters) may be represented by the formula (RO)x--A-(oH)nx in which R represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms,

A represents the residue of the inorganic acid (as for example, the radical S02, the radical PC. the radical SiO, the radical B, etc.)

n represents the number of hydrogen atoms, in the uncombined polybasic acid from which the ester is derivable, which are replaceable by a metal (herein designated as replaceable hydrogen atoms), and

a: is 1 or more but not greater than n-l. As is well known a partial ester, or acid alkyl ester,

of a polybasic inorganic acid is an ester in which i at least one of the replaceable hydrogen atoms of the parent polybasic inorganic acid has not been replaced.

It is to be noted, in the case of acid alkyl esters which are derivatives of polybasic acids containing 3 or more replaceable hydrogen atoms in which more than one of said hydrogen atoms have been replaced by organicradicals, the said organic radicals (represented by R in the above formula) may be the same or different.

The alkyl ester salts employed in accordance with the present invention comprise especially the soluble salts of the herein described acid alkyl esters, e. g. those resulting from the combination of any suitable metal or base, including the organic bases, with the said acid alkyl esters. It is particularly advantageous, however, to use the alkali metal salts of the acid alkyl sulfates, phosphates, bore-sulfates and boro-phosphates or the salts formed by the interaction of the acid alkyl sulfates, phosphates, boro-sulfates and boro-phosphates with aliphatic or aromatic amines, for example, the alkylol amines. Thus the potassium and sodium salts of the said acid alkyl esters, or the salts of the acid alkyl esters with diethanolamine, triethanolamine, pyridine, or other salt-forming ammonium bases, may be used.' The sodium salts, in view of their extremely high solubility in water and alkaline printing pastes (which permits their incorporation into such printing pastes in almost any desired amount), are of especial value.

The said salts of alkyl esters employed in accordance with the present invention may be pre pared in any manner well known to the art; as for example, by the treatment of the corresponding alcohol, in the presence or absence of a solvent of diluent, with a suitable inorganic reagen" (such as phosphoric acid, phosphorus chloride or oxychloride, concentrated sulfuric acid,

and/or chlorsulfonic acid, and/or one or more of these in the presence of boric acid, etc.) and neutralization of the resulting acid alkyl ester with an inorganic or organic base which forms a readily soluble salt with said acid alkyl ester.

It may be noted that the alkyl sulfuric acids and the alkyl bore-sulfuric acids resulting from the I use of sulfuric acid or chlorsulfonic acid in the absence or presence of boric acid, may contain varying amounts of sulfonic acids which are sometimes produced due to secondaryreactions;

. the presence of such sulfonic acids, however, does 'not impair the usefulness of the alkyl sulfuric acids and alkyl hero-sulfuric acids in accordance with the present invention.

As illustrating acid alkyl esters, the solublev ethyl, propyl, butyl and amyl boro-phosphoric acids; etc.

Of special interest in connection with the-present invention are the various soluble'salts, and particularly the alkali metal and organic amine salts, of the sulfuric acid monoesters of the various monohydric alcohols which contain not more than 5 carbon atoms, including those which contain single or multiple bonds, straight chains and branched chains; as for example,the sodium or potassium salts of the following: ethyl sulfuric acid; normal and isopropyl sulfuric acids; the mono sulfuric acid ester of methyl ethyl carbinol; normal-, iso-, and tertiarybutyl sulfuric acids; the mono sulfuric acid esters of pentasol, of secondary butyl carbinol, and of methyl-n-propyl carbinol; pentene-2-sulfuric acid; normal amyl sulfuric acid; tertiary amyl sulfuric acid; amylene sulfuric acid; etc. The salts of the monoalkyl sulfuric acids which contain from 3 to 5 carbon atoms in the alkyl group are' of especial value in the pad-jig dyeing and printing with vatdyes in accordance with the present invention. Those, in which the alkyl group comprises an iso-alkyl radical (as for excorresponding alcohol, in the presence or absence of a solvent or diluent, with a suitable sulan isobutyl radical:

.fonating agent (such as concentrated sulfuric acid and/or chlorsulfonic acid or the like), or by-the interaction of sulfuric acid or the like with the corresponding unsaturated hydrocarbon. Thus, a suitable alcohol dissolved in an inert organic solvent may be reacted with the necessary.amount of sulfonic acid to form the sulfuric acid mono ester of the alcohol, the mixture then may be blown with air to remove hydrogen chloride formed, and subsequently stirred with water.

Mixtures of salts of the said acid alkyl esters may also be employed in accordance with the present invention. For example the salts of suitable inorganic or organic bases with the commercially available and cheap mixtures of alkyl sulfuric acids resulting from the sulfuric acid treatment of mixed gaseous and lighter liquid unsaturated hydrocarbons, such as the mixtures produced in the recovery and removal of unsaturated hydrocarbons in the production and purification of gasoline in the so-called cracking proces of petroleum distillation.

The percentage of assistant of the present invention that may be employed is not critical and 7 advantageous action may be secured by subjecting the cloth to be dyed or printed to a preliminary treatment with the solution of the said alkyl ester salt, as for example, impregnation. In

copending application Serial No. 673,030, filed May.

26, 1933, vat dye compositions in the form of powders are described containing vat dyestufis and alkyl ester salts of the type her'ein disclosed.

Such compositions, in view of their content of said alkyl ester. salts, may be employed in accordance with the present invention merely by mixing them with the usual thickener, alkali (potassium carbonate), reducing agent (sodium formaldehyde sulfoxylate), water and/or other usual ingredients of printing pastes, and employed for printing in the ordinary manner. The acid alkyl esters may also be employed as such in preparing printing pastes and padding liquors .containing .alkali inasmuch as the salts of said acid alkyl esters will be formed in the resulting compositions and there exert their advantageous action.

In dyeing by the printing process the printing paste may contain printing catalysts or boosters, reduction accelerators, hydrotropic and/or enolyzing substances, and the like.

It is to be noted that under the term hydrotropic substances are to be understood not only the substances specifically enumerated by Neuberg and Tamba (compare Carl Neuberg, Biochemische Zeitschrift, vol. 76, 1916, page I01 ff.,

and Tamba, Biochemische Zeitschrift, 'vol. 145,

1924, page 415; Carl Neuberg, Sitzungsberichte der Koengl. Preussischen Akademie der Wissenschafter, 1916, page 1034), but all of those substances, which comply with the definition of the word fhydrotr'opic as given by Neuberg. As examples of such substances the following may be mentioned: urea, substituted ureas, thiourea, hexamethylenetetramine, the potassium salt of ethyl'sufonic acid, potassium or sodium isovalerate, the alkali metal salts of the following acids: isobutyric acid, phenylacetic acid, benzoic acid, o-toluene-carboxylic acid, salicylic acid, the henzene sulfonic acids, p-toluene-sulfonic acid, the benzene sulphinic acids, 1.4-toluene sulphinic acid, naphthalene sulfonic acids,aniline sulfonic acids and substitution products thereof, naphthylamine sulfonic acids (as for example, 1-aminonaphthalene 3.6.8 trisulfonic acid), pico- The said alkyl ester salts are in National '70 linic acid, hydroaromatic carboxylic or sulfonic acids, and the like. It will be further noted that substances which are not, strictly speaking, hydrotropic substances but which possess enolyzing properties are included, as for example, l-naphthalene sulfonic acid (sodium salt).

The presence of enolyzing substances in vat dye printing pastes prepared in accordance with the present invention is of particular advantage in connection with vat dyes of the indigoid and mmindigoid series, inasmuch as they tend to minimize or prevent isomerization of the reduced vat dye to the keto form.

If desired, foam breaking or foam-preventingv agents may also be included in the compositions of the present invention in connection with vat dyes which have a tendency to produce foaming.

'I'he invention may be employed in connection with vat dyes of all types including those derived from anthraquinone, indophenols, various indigoid, thioindigoid and indirubin compounds, etc.; as for example, indanthrones, pyranthrones, fiavanthrones, dibenzanthrones, isodibenzanthrones, perylene quinones, anthanthrones, dibenzpyrene quinones, anthrimidocarbazols, naphthacridones, indigo, thioindigo, indirubin, etc., including derivatives thereof, such as their halogen, nitro, sulfur, and/or alkoxy derivatives. The term vat dye compound is intended to cover specifically the vat dye in the insoluble form and in the form of the free leuco compound c. a soluble metal (or organic ammonium base) salt thereof (in the presence of alkaline compounds.) Ordinarily a vat dye printing paste contains the vat dye in the insoluble form.

It may also contain the vat dye in the leuco form either alone or in addition to the vat dye, as when the vat dye is prereduced.

Examples of vat dyestuffs with which the present invention may be employed are such indigoid and thioindigoid dyestufis as the following:

National Vat Pink (6,6f-dichlor-4A' dimethyl-2,2'-bisthio-naphthenindigo) National Vat Pink BG Color Index No. 1210 National Vat Yellow G Color Index No.1196 National Vat Yellow R Color Index No. 1170 and such anthraquinone vat dyesas the following:

National Carbanthrene Blue RS Color Index No.

National Carbanthrene Blue 3G Color Index No. 1109 National Carbanthrene Blue GCD Color Index No. 1113 National Carbanthrene Yellow G--- Color Index No. 1118 National Carbanthrene G o l d e 11 Orange 2RT Color Index No. 1097 National Carbanthrene G o l d e 11 Orange G Color Index No.-1096 National Carbanthrene Blue Green FFB Color Index No. 1173 National Carbanthrene Violet 2R Color Index No. National Carbantlirene Dark Blue DR Color Iiidex No. National Carbanthrene Flavine GC Color Index No. National Carbanthrene Red Violet :ZRNX Color Index No.

Carbanthren Brilliant Green supra Color Index No. National Carbanthrene Green B Color Index No. National Carbnnthrene Brown AR Color Index No. National Carbanthrene Olive R Color Index No. National Carbanthrene Red BN Color Index No. NationalCarbanthrene Red AFF Color Index No. National Cai-banthrene Black J Furthermore, mixtures of two or more vat dyes may be employed, for example when it is desired to produce compound shades such as scarlets, navy blues, blacks and browns.

Other assistants may be used together with the assistants of the present invention, as their effectiveness is not impaired by the use of any of the usual assistants; for example, suitable monoor polyhydric alcohols (f. 1., glycerine) hydroxyalkyl ethers, alkylol amines, etc.

, The invention is not restricted to any particular method of'applying the vat-dyes but includes the dyeing of piece goods (cotton, rayon, etc.) by the pad-jig process and the printing of piece goods by' the various printing processes (including discharge printing and color discharge print- 'ing as well as ordinary types of vat dye printing),

in which various methods of applying the padding liquor or printing paste are employed.

The alkyl ester salts of the present invention yield especially beneficial results. Because of their non-volatility, there is no danger of their evaporation prior to the ageing process; hence the uniformity of the vat dye printing pastes is retained and a proper drying of the printed material is secured. While formerly known assistants produce little or no improvement in prints of light shades, the compounds of the present invention are especially distinguished by the noticeable increase in printing strength obtainable by their use, even with very light shades. The alkyl ester salts of the present invention are particularly valuable in pad-jig dyeing and printing of socalled' gray-goods (unbleached cotton fabrics, raw regenerated cellulose fabrics and the like) with vat dyes, inasmuch as the dyeings and prints obtained with the aid of such alkyl ester salts have exceedingly high tinctorial value and excellent penetration as compared with dyeings and prints made in the absence of said .alkyl ester salts.

The salts of the acid alkyl esters of the present invention are further of particular benefit in dyeing and printing with vat dye compositions which contain heavy metal compounds as printing catalysts or boosters or reduction accelerators. It

has heretofore been suggested to employ compounds of heavy metals (and metalloids) which are capable of exhibiting more than one valency, as for example, the salts (halides, sulfates, acetates, etc.), oxides or hydroxides of iron, copper, tin, zinc, titanium, chromium, nickel, mercury, arsenic, etc., for this purpose. Many compounds of this type do not exhibit, however, the desired catalytic or boosting-" action when employed in the usual printnig pastes. In accordance with the present invention, such heavy metal compounds are employed in conjunction with the acid alkyl esters herein described, whereby an efiective catalytic reducing action on the vat dyes is secured. Thus, when the alkyl ester salts herein described are employed in connection with heavy metal salts of said type exhibiting catalytic or boosting? action when present, for example, in proportion to about 0.05 to about 3 per cent by weight of the vat dye printing pastes, an increase in the catalytic or boosting action of said heavy metal salts is obtained. Further, when the hereindescribed acid alkyl esters are employed in conjunction withheavy metal compounds of the said type not exhibiting catalytic or boosting action in the usual vat dyestuff printing pastes, catalytic or boosting" action is secured. This "combined advantageous effect may be secured by employing the said heavy metal compound in the presence of a soluble salt of an acid alkyl ester,

printing thickener of this example to, for

i for example, one of those hereindescribed, or by employing the heavy metal compound and acid alkyl ester in combination, as for example, in the form of a salt of the heavy metal with the acid alkyl ester (as for example, the iron, nickel, cobalt, manganese or chromium salts of the acid alkyl sulfates, phosphates, hora-sulfates and hora-phosphates hereinbefore mentioned). Of particular value in this connection are the salts and other compounds containing nickel, cobalt or manganese.

The following examples, in which the parts are by weight, will serve to illustrate the invention.

Textile printing A standard starch-tragacanth thickener is prepared by mixing together and boiling the following ingredients, any loss of water being replace after boiling:

1 part cornstarch 3 parts British gum 1 part 5% tragacanth solution 5 parts water.

Example 1 Part 1.A'stock printing thickener is made up 20 parts of National Vat Orange R paste (containing about 13% of dye solids).

'70 parts of the stock printing thickener of' Part 1, and

parts of dry isobutyl sodium sulfate are thoroughly mixed to insure a paste of uniform composition. The resulting vat dye' printing paste is printed, for example by means of an engraved roll, upon a cotton fabric, the printed fabric is dried, and then subjected to the aging action of air-free, saturated steam at 102 C. for 3 to 5 minutes. After this aging treatment the fabric is rinsed ina streamfof cold water and is then soaped at boiling temperature in the presence of air until the dye-is fully developed. The resulting printed fabric exhibits full penetration and a strength of print 20% to 30% greater than is obtained by the same printing method and printing paste but with the isobutyl sodium sulfate omitted.

Similar improved results may be obtained by mixing 20 parts of the vat dye powder described in Example '7 of copending application Serial No. 673,030, :6 ed May 26, 1933 (which contains isobutyl sodium sulfate as a part thereof) with 80 parts of the stock thickener of Part 1 of the present example and employing the resulting paste in the printing process of this example.

Prints of lighterjshade may be obtained by cutting the printing paste as given in Part 2 of the present example with a thickener for reduction containing a considerably lower percentage of potassium carbonate and sodium formaldehyde I sulfoxylate, for example a thickener obtained by reducing the amounts of potassium carbonate and sodium formaldehyde sulfoxylate in the stock pie, about 7% potassium carbonate and 5% sodium formaldehyde sulfoxylate.

The isobutyl sodium sulfate may be prepared,

for example, by reacting 516 parts of isobutyl al-c,

cohol with 813 parts of chlorsulfonic acid at a temperature of about 14 to 16 (7.; adding the resulting reaction mixture slowly to 8100 parts of water to which 418 parts of hydrated lime, Ca(0H)2, have been added, while cooling the resuiting mass to a temperature of about 20 0.;

filtering ofl calcium sulfate; converting the calcium isobutyl sulfate, contained in the filtrate, to sodium isobutyl sulfate, for example, by treating with sodium carbonate and removing calcium carbonate, and recovering the sodium isobutyl sulfate in the form of a dry solid.

Example 2 20 parts of National Vata Red Violet RH paste (containing about 18% of dye solids) 68 parts of the stock printing thickener of ample 1, rt 1, and

12 parts of isopropyl sodium sulfate areintimately mixed to produce a uniform printing paste, and the paste is printed and developed as in Example 1. A strength of printis obtained which is 25% greater than tt obtained without isopropyl sodium sulfate.

Example 3 20 parts of National VatPink Paste (cont' .1 1:."

% of solids),

68 parts of the stock-printing thickener of pie 1, Part 1, and

12 parts of sodium ethyl sulfate are intimately mixed to form a uniform printing paste. When printed and developed as in ample Lthe resulting prints are brighter-and 15 to 20% stronger than those obtained without the addition of sodium ethyl sate.

Enample d 1 I of 5,5-dior=7,i'-dibrom indigo (20% 70 parts of the stock printing thickener ample 1, Part 1, and

iil parts of n-amyl sodl sulfate are mixed,

printed and developed as in the preceding examples. A print of improved streh and brightness is obtained.

' Example 5 1 indigo may be replaced by 20 parts of Natio v Vat pinkFF paste (containing 15% of dye solids).

Emmpie 6 20 parts of National Vat Pink FF paste (containing 15% of dye solids) 68 parts of the stock printing thickener of Example 1, Part 1, and 12 parts of sodium isobutyl boro-sulfate are intimately mixed to form a uniform printing paste. When printed and developed as in Example 1, the resulting prints are brighter and from 20 to stronger than those obtained without the addition of the sodium isobutyl boro-sulfate. (The sodium isobutyl boro-sulfate may be prepared, for example, by stirring 918 parts 01: 100% sulfuric acid with 200 parts of boric acid at a temperature of 75 C. until a uniform solution results; then adding 320 parts of isobutyl alcohol in a slow stream with agitation, while keeping the temperature at to (3.; after stirring this solution two hours, running it into a mixture of 2000 parts of caustic soda and 1000 parts of isobutyl alcohol while stirring and cooling; permitting the resulting mixture to stratify; drawing off the aqueous layer; neutralizing the remaining isobutyl alcohol layer with sodium carbonate or caustic soda, heating it to boiling and filtering hot; and drying the filtrate on a. rotary drum drier.)

Example 7 Part 1.A printing thickener is prepared by mixing 52 parts of the above standard starch tragacanth thickener, 17 parts of potassium carbonate, 14 parts of sodium formaldehyde sulfoxylate,

5 parts of glycerine, and 12 parts of water.

A printing paste is formedby mixing produced.

PAD-J16 DYEING Example 8 A padding liquor is prepared containing the following ingredients in the following approximate amounts:

National Carbanthrene Blue GCIQ in the form of the double paste (Color Index No. 1113) grams 30 n-Amyl sodium sulfate d0 5 Gum Tragacanth do 3.6 Gum Arabic do 6.8 Water sumcient to make up volume to approximately cc. 1700 for example, by mixing the dyestufi paste with the n-amyl sodium sulfate, which is preferably employed in the form of an aqueous solution, adding the gum arabic and gum tragacanth in the ,form of water solution, bringing the total volume up to the said volume with additional water, and straining the mixture through a cloth of fine mesh. Cotton piece goods are padded or printed with the liquor in any suitable manner (for example, by passing the cloth between rolls through a vessel containing the padding liquor which is preferably at a temperature of about F.). The padded or printed cloth is then treated on the jig in the well known manner, for example, in an alkaline hydrosulfite bath preferably maintained at a temperature of about to F., wherein the color rapidly develops, and is then finished in any convenient known way.

The dyeings thus obtained are of an increased brightness and fullness of shade and are better penetrated as compared with those obtained by the same process but with the employment of 2. padding liquor containing no n-amyl sodium sulfate.

In this example any one of the acid alkyl ester salts hereinbefore referred to, and especially the sodium and potassium salts of the acid alkyl sulfates may be used instead of n-amyl sodium sulfate. Similar improved dyeings may be obtained by replacing the vat dye paste and n-amyl sodium sulfate of the present example by 30 grams of the powder produced in Example 10 of copending application Serial No. 673,030, filed May 26, 1933, and containing isobutyl sodium sulfate as a part thereof.

The action of the acid alkyl ester salts as penetrating agents and surface tension lowering agents may be enhanced by adding to the padding liquor a small amount of caustic alkali, a1- kali metal carbonate, trisodium phosphate, sodium silicate, etc. For example, 1 to 3 parts of said substances may be added to the padding liquor of this example.

As above indicated, the advantageous action of the salts of the acid alkyl esters as assistants in pad-jig dyeing and printing also may be secured by pretreating the fiber with the salt of the acid alkyl ester. The following example illustrates such pretreatment.

Example 9 Bleached or unbleached cotton cloth is padded with a solution containing, for example, about 5 to about 30 parts of sodium isobutyl sulfate or any of the other salts of acid alkyl esters herein described, per 1000 parts of water, for example by passing the cloth through the solution contained in a padding box equipped with squeeze rolls. Preferably, the padding liquor also contains .about 2 to about 5 parts of gum tragacanth or such as caustic alkalies, alkali metal carbonates, H

trisodium phosphate, etc. may also be added to the padding liquor.

This application is a continuation-in-part of applications Serial Nos. 673,030 and 673,031, filed May 26, 1933.

I claim:

1. In the dyeing of textile fibers by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye compound, the improvement which comprises carrying out the dyeing with the aid of a soluble salt of an acid alkyl ester containing not more than 5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol containing notmore than 5' carbon atoms.

2. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye, the improvement which comprises carrying out the absorption of the leuco-compound by the fiber in the presence of a soluble salt of an acid alkyl-ester containing not more than'5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol containing not more than 5 carbon atoms.

3. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye isformed in the presence of the fiber by reduction of a vat dye, the iniprovement which comprises carrying out said reduction in the presence of an alkali metal salt of an acid alkyl ester having the formula P0, 11 represents the number of replaceable hy- I drogen atoms in the uncombined acid from which the ester is derivable, and .1: represents a whole number not greater than n-l? v 4. In the dyeing of textile fibers of the vegetable type by a-process in which a leuco-compound of a vat dye is formed in the presence of the fiber by'reduction of a .vat dye, the improvement which comprises carrying out said reduction in the presence of an organic amine salt of an acid'alkyl.

ester having the formula (RO)x A--(OH)n-x in which R. represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S0: or the radical PO, nrepresents the number of replaceable hydrogen atoms in the uncombined polybasic acid from which the ester is derivable, and a: represents a whole number not greater than n1.'

5. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye is formed in the presence or the fiber by reduction of a vat dye, the improvement which comprises applying to the fiber a vat dye composition containing a vat dye in the unreduced form and a soluble salt of an acid alkyl estervhaving the formula RmPA-(omnq in which R represents an aliphatic Hydrocarbon radicalwhich contains not more than 5 carbon atoms, A represents the radical S0: or the radical P0, 11 represents the number of replaceable hydrogen atoms in the uncombined polybasic acid from which the ester is derivable, and a: represents a whole number not greater than n-1.

6. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye is formed in the presence ofthe fiber by reduction of a vat dye, the improvement which comprises applying to the fiber a vat dya composition containing a vat dye in the unreduced form and a soluble salt of an acid alkyl sulfate containing not more than 5 carbon atoms in the alkyl group.

I. In the dyeing of textile fabrics of the vegetable type by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye compound,

an alkali, a reducing agent, a thickener and an e;

- alkali metal salt of an acid alkyl ester having the formula (R0) xA(OH) n-x drogen atoms in the uncombined polybasic' acid H from which the ester is derivable, and 1: represents a whole number not greater than n'1.

' 8. In the dyeing of textile fabrics of the vegetable type by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye compound, a reducing agent, an alkali and an aikali metal salt of an acid alkyl sulfate containing 2 to 5 carbon atoms,

9. In the dyeing of textile fabrics of the vegetable type by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye in the unreduced form, a reducing agent, an alkali and isobutyl sodium sulfate.

' 10. In the dyeing of textile fibers of the vegetable type by the pad-jig process, the mprovement which comprises padding the textile fiber .with a padding liquor containing a vat dye in the unreduced form and a soluble salt of an. acid alkyl ester having the formula L a in which R represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S02 or the radical.

acid alkyl sulfate containing 3 to 5 carbon atoms.

12. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye is-formed in the p esence of the fiber by reduction of a vat dye compound, the improvement which comprises treating the fiber to be dyed with a solution of a salt of an acid alkyl ester containing not more than 5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol, containing not more than 5 carbon atoms, and subjecting the treated fiber to the dyeing process.

13. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat. ye is formed in the presence of the fiber by reduction of a vat dye compound, the improyement which comprises treating the fiber to be dyed with a solution of a salt of an acid alkyl ester having the formula in'which R represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S02 or the radical PO, n represents the number of replaceable hydrogen atoms in the uncombined polybasic acid from which the ester is derivable, and a: represents a whole number not greater than u-l, and subjecting the treated fiber to the dyeing process.

14. In the dyeing of textile fibers of the vegetable type by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye compound, the improvement which comprises treating the fiber to be dyed with a solution of an alkali metal salt of an acid alkyl sulfate containing 3 to 5 carbon atoms.

15. A vat dye paste for direct application to textile fibers, comprising a vat dye in the unreduced form, a thickener, water and a soluble salt of an acid alkyl ester containing not more than 5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol containing not more than 5 carbon atoms.

16. A vat dye paste for direct application to textile fibers comprising a vat dye in the unreduced form, a thickener, water and a soluble salt of an acid alkyl ester having the formula in which R represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S: or the radical PO, 1!. represents the number of replaceable hydrogen atoms in the 'uncombined polybasic acid from which the ester is derivable, and a: represents a whole number not greater than n-l.

1'7. A vat dye paste for direct application to textile fibers comprising a vat dye in the unreduced form, a thickener, water and an alkali metal salt of an acid alkyl sulfate containing 2 to carbon atoms.

18. A vat dye paste for direct application to textile fibers comprising a vat dye in the unreduced form, a, thickener, water and isobutyl sodium sulfate.

19. In the dyeing of textile fibers by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye compound, the improvement which comprises carrying out the dyeing with the aid of a compound of a heavy metal capable of exhibiting more than one valency and a soluble salt of an acid alkyl ester containing not more than 5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol containing not more than 5 carbon atoms.

20. In the dyeing of textile fibers by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye compound, the improvement which comprises carrying out the dyeing with the aid of a salt of one of the metals nickel, cobalt and manganese, and a soluble salt of an acid alkyl ester having the formula (R0) x- -A(OH) 11-1: in which R represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S0: or the radical PO, n represents the number of replaceable hydrogen atoms in the uncombined acid from which the ester is derivable, and :1: represents a whole number not greater than n1.

21. In the dyeing of textile fibers of the vege table type by a process in, which a leuco compound of a vat dye is formed in thepresence of the fiber by reduction of a vat dye, the improvement which comprises applying to the fiber a vat dye composition containing a vat dye in the unreduced form, a soluble salt of an acid alkyl ester containing not more than 5 carbon atoms in the alkyl group and derivable from a polybasic inorganic acid and an aliphatic alcohol containing not more than 5 carbon atoms, and a salt of a heavy metal capable of exhibiting more than one valency.

22. In the dyeing of textile fibers by a process in which a leuco-compound of a vat dye is formed in the presence of the fiber by reduction of a vat dye compound, the improvement which comprises carrying out the dyeing with the aid of a compound of a heavy metal capable of exhibiting more than one valency and a soluble salt of an acid alkyl ester having the formula in which R. represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radicalSO: or the radical PO, n represents the number of replaceable hydrogen atoms in the uncombined polybasic acid from which the ester isderivable and a: represents a whole number not greater than n-l.

23. In the dyeing of textile fabrics by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye in the unreduced form, an alkali, a reducing agent, a thickener, an alkali metal salt of an acid alkyl sulfate containing 3 to 5 carbon atoms, and a sulfate of a heavy metal capable of exhibiting more than one valency.

24. In the dyeing of textile fabrics by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye in the unreduced form, a salt of one of the metals nickel, cobalt and manganese, and an alkali metal-salt of an acid alkyl ester having the formula in which It represents an aliphatic hydrocarbon radical which contains not more than 5 carbon atoms, A represents the radical S0: or the radical P0, 11. represents the number of replaceable hydrogen atoms in the uncombined polybasic acid from which the ester is derivable and 1: represents awhole number not greater than n -1.

25. In the dyeing of textile fabrics by a printing process, the improvement which comprises applying to the textile fabric a printing paste containing a vat dye in the unreduced form, a salt of one of the metals nickel, cobalt and manganese, and an alkali metal salt of an acid alkyl sulfate containing 2 to 5 carbon atoms.

JEAN G. KERN.