US2450773A - Dyeing of wool with indigo dyestuffs - Google Patents

Description

Patented Oct. 5, 1948 'DYEING OF'WOOL WITH INDIGO 'DYESTUFFS Edward- Weber,.-VVinchester, Mass, assignorto Allied Chemical 8;- Dye Corporation, New York, 'N...,,a.c0rporation of New York NoDrawing; Application March 30, 1944, Serial'No. 528,772

Claims.

This inventionrelates't'o the dyeing of: animal fibers.- and especially wool, withindigoid vatidyestuil:s-..v Itrelates more. particularly to, an: improved method. of. exhausting an: ammoniahydrosulfite vat of an .indigoid vat-.dyestufi; or related: dye-liquor, employed in' the: dyeing of animalfi-bers.

The dyeing of animal fibers withzindigo-id'vat dyestuffs, and=especially indigo, presentsa number-of: difiicultie which ordinarily, are not en'- countered in the; dyeing of cotton and other-vegetable fibers. Thus,,.beoause of the. chemical nature of the animal fibers, it is-necessar-y; to avoid theme of strongly alkaline-vatsorrelated dye liquors. ticetodyewoolen stock, yarn, slubbing. or piece-- goods in a weakly alkaline vat;. or with a circulating-liquor, containing a leuco-compound of an indigoid vat dyestui'l, aqueous odiurnhydrosulfite and. aweak. alkali (such as ammonium hydroxide, sodium. carbonate, or the like): and preferably also containing a dispersion assistant (such asa-protective colloid or anorganic dispersing agent; for example, glue; gelatin, syn-- thetic organic compounds of the. alkyl aryl sulfonate type,.and the like) Priorito' thepresent invention, in thedyeing. of animalfibers with indigoid vat d'yestufis, it. wasknown to exhaust. an ammonia-hydrosulfite vat ofan' indigoid vat dyestuff, or related dye liquor; by' adding. thereto ammonium sulfate or other acidic substance; such. as. an. acid. (e. g.,.

avneutral salt, whereas for'the. dyeing of animal fiber it was considered: necessary, priort'o' the present invention, to" neutralizethei vat by. means ofan acidic substance in'order' to exhaust it..

(See, for example, American Dyestufii Reporter, vol. XIX-A930, page 241.)

. It. has been discovered in accordance with' thev present inventionrthati. the neutral; alkali metal sulfates and the alkali metal chlorides not only are: efiective as exhausting agents for ammonia hydrosulfit'e-vats in the-dyeing of animal fibers It has accordingly been the-.prac

2. with indigoid vat dyestuffs, but in some cases produce superior dyeings. For example, in the dyeing of woolen piece-goods with indigo from an ammonia-hydrosulfite-glue vat; it has been found, in accordancewiththe. present invention, if sodium sulfate (e.- g., Glaubers salt) is added to the vat as an exhausting agent, the resulting dyeings' are about 10% stronger than 'dyeings obtained under-similar c0nditions-with the same materials but with ammonium sulfate as the exhausting agent, and thesdyeings are otherwise substantially identical.

Thus, in accordance with the present. invention, dyeings whichraraof squalor greater tinctorial strength, as compared with those obtained with the use of. ammoniumsulfate, can be. ob-

I tained without sacrificing any of the important qualities of the dyeings' (especially uniformity, penetration, andfastness to" crocking) by the use of'such' readily; available and cheap salts as sodium sulfate and sodium chloride. (It. will'be understood that where sodium sulfate isreferrcd to hereirrand' in the claims, the neutral; sulfate, NazSO4, with or withoutwater of crystallization, isintendedfi' The neutral alkali rnetal sulfate or alkali.- metal "chloride (for example; sodium sulfate, potassium sulfate, sodium "chloride, potassium chloride; lithium chloride, 'etc;) 'is' preferably addedto the 'vat' or other dye liquor in small amounts during the course of thetdyeing, to effect a gradual precipitation of" the leuco cornpound and thereby promote even dyeings characterized by good penetration and fastness .to' crocking. It i preferably"'added' to the' dye. liquor: after dyeing has progressed to a substantial degree, inaccordance with the usual pram tioe in theart in exhausting indigoid" vat'dyestuff liquors; it maybe added earlier, however,.

if desired.-

The invention will be illustrated bythe following specific-example, but it isto'beunderstood that the invention is'not limitedto the" cletailsthereof an'dthat' changes maybe made without departing from the scope; of" theinven tion.

EXAMPLE Elevenounce woolen ,piecagoods were processed and dyed .in rope form inTan ordinary piece-dye kettle (which machine) open. toQthe;

atmosphere in. the following..manner, .theratiO of the goods to the dyebath or liquor beingal- Ways maintained at about 1:20. Eire amount 3 Washing The goods were first washed by circulating them for 30 minutes in a bath at 180 F. and

composed of water, 2 lbs. of Nacconol NP. (9. commercial surface-active agent comprising a mixture of alkyl benzene sodium sulfonate derived from kerosene) and 4 lbs. of 26% ammonium hydroxide. The goods were then washed free from alkali with water.

Bottoming with chrome dyes A dye-bath was prepared by warming the water in the kettle to 110 F. and adding:

2 oz. of Alizarol Azurine ECA 3 lbs. 8 oz. of Superchrome Blue BC 1 lb. 3 oz. of Superchrome Blue B High Conc.

2 lbs. 8 oz. of Superchrome Red E03 3 oz. of Superchrome Yellow RN (C. I. 197) 10 lbs. of calcined Glaubers salt (NELZSOQ 6 lbs. of 56% acetic acid.

The winch was set in motion, and the dyebath was heated'to boiling during one hour. The bath was boiled for an additional hour and then cooled to 160 F. (by displacing part of the exhausted dyebath with cold water) at which point 3 lbs. of sodium bichromate, dissolved in water, were introduced. The bath was reheated to boiling during 15 minutes, and boiled for 45 minutes,

after which it-was displaced with water. The goods were rinsed until a clear rinse liquor was obtained. I

Topping ,with indigo A stock vat of indigo was prepared by pasting 10 lbs. of indigo NAC 20% Paste (Color Index 117'?) with a solution of 1 1b. of caustic soda flakes in 5 lbs. of cold water, sprinkling in 1 lb. 11 oz. of sodium hydrosulfite powder, and heating the resulting mixture to 125 F. until reduction of the indigo to the leuco compound was complete.

A bath was prepared by adding to the water in the kettle:

6 lbs. of 26% ammonium hydroxide, 2 lbs. of animal glue, and 3 lbs. of sodium hydrosulfite. The resulting mixture. was heated to 125 F. and the goods were circulated for 10 minutes. The stock vat of indigo was quickly added to the bath, and dyeing was carried out at 125 F. for 20 minutes. Then 10 lbs. of calcined Glaubers salt (Na2SO4), dissolved in 100 lbs. of water, were added slowly during 10 minutes to exhaust the dyebath. The goods were then rinsed and circulated through cold running water until the leuco-indigo was oxidized substantially completely.

Thedyed goods thus obtained were scoured with soap in the conventional manner to remove loosely-held indigo, rinsed and dried.

The goods were dyed full and well-penetrated navy blue shades possessing good evenness (levelness) and fastness to cracking.

In the above examples, sodium sulfate is used as an exhausting agent for' an ammonia-hydrosulfite-glue vat in connection with the dyeing of chrome-bottomed woolen piece-goods in rope form with indigo, which is claimed in my application Serial No. 528,711, filed March 20, 1944, now

abandoned. The invention is not limited thereto,

however, 7

Thus, the invention may be applied to the dyeing of wool which has not been predyed with another dyestuff; for example, it may be employed in th dyeing of carbonized or uncarbonized wool in an ammoniacal indigo vat.

Instead of sodiumsulfate, another neutral alkali-metal sulfate or alkali-metal chloride or a mixture thereof may be employed as-exhausting agent. The amount of exhausting agent which is required depends upon the conditions employed (e. g., amount of dye liquor, temperature, etc.) and can be easily determined in each case; for example, by slowly adding various amounts of the exhausting agent to the dye liquor, and noting the minimum amount of exhausting agent which produces dyeings of maximum tinctorial strength (corresponding for all practical purposes with optimum exhaustion of the dyebath). Thus, in the foregoing example, the use of substantially less than 10 pounds of sodium sulfate results in an incomplete exhaustion of the dyebath, while the addition of substantially more than 10 pounds of sodium sulfate does not noticeably improve the tinctorial strength of the dyeing. In general, at least per cent of sodium sulfate, based on the weight of the dye liquor, or equivalent weight of another neutral alkali metal sulfate or an alkali metal-chloride, is required to effect substantially complete exhaustion of the dyebath.

The dye liquor need not contain glue; but preferably it contains a dispersion assistant (such as glue and/or another protective colloid or organic dispersing agent).

The invention includes the dyeing of proteinous fibers of various kinds, including natural animal fibers (such as wool, silk, hair and the like) and artificial animal fibers (such as those derived from casein, soybean and the like), all of which are comprehended within the generic term ani- J mal fibers herein and in the claims.

Vat Orange R Color Index No. 1217 Vat Red Violet RII Color Index No. 1212 Vat Pink FF Am. Assoc. Textile Chemists and Colorists, Vol. XIX (1942), page 523. Brilliant Indigo 4BR. Color Index No. 1184 Brilliant Indigo KMR Color Index No. 1183 I claim:

1. In the dyeing of wool with an indigo by treating the wool with a dye liquor comprising an indigo in the leuco form, sodium hydrosulfite and ammonium hydroxide, the improvement which comprises exhausting the dye liquor by adding thereto an alkali-metal salt selected from the group consisting of the neutral alkali-metal sulfates and the alkali-metal chlorides.

2. In the dyeing of wool with indigo by treating the wool with a dye liquor comprising indigo in the leuco form, sodium hydrosulfite and ammonium hydroxide, the improvement which comprises exhausting the dye liquor by adding sodium sulfate thereto.

3. In the dyeing of wool with an indigo from an ammonia-hydrosulfite-glue vat, the improvement which comprises adding sodium sulfate to the vat in small amounts at a time, while continuing the dyeing, the total amount of sodium sulfate being at least sufficient to exhaust the vat substantially completely.

4. The method of dyeing wool with indigo which comprisessubjecting wool to a dyeing treatment with a weakly alkaline dye liquor containing leuco-indigo, sodium hydrosulfite, ammonium hydroxide and an organic dispersing assistant, then adding sodium sulfate to the dye liquor, as an exhausting agent, and continuing the dyeing treatment.

5. The method of dyeing wool with indigo which comprises dyeing woolen piece-goods in a weakly alkaline vat containing leuco-indigo, sodium hydrosulfite, ammonium hydroxide and glue, and adding sodium sulfate to the vat in small amounts at a time, as an exhausting agent, while continuing the dyeing, the total amount of sodium sulfate being at least sufiicient to exhaust the vat substantially completely.

EDWARD WEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 972,066 Deinet Oct. 4, 1910 1,148,966 Hebden Aug. 3, 1915 1,199,273 Iljinsky Sept. 26, 1916 1,431,136 Villiger Oct. 3, 1922 1,546,969 Clavel July 21, 1925 1,716,720 Ellis July 11, 1929 1,819,027 Hood Aug. 18, 1931 FOREIGN PATENTS Number Country Date 166,835 Germany Jan. 12, 1906 213,266 Great Britain Jan. 1, 1906 340,267 Great Birtain Dec. 19, 1930 419,061 Germany Sept. 19, 1925 OTHER REFERENCES Matthews: Application of Dyestuffs, N. Y., 1920,

20 pages 413, 415, 428, 429, 430, 449.

Certificate of Correction Patent N 0. 2,450,773. October 5, 1948. EDWARDQWEBER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 50, for the words which machine read winch machine column 3, lines 68 and 69, strike out Serial N 0. 528,711, filed March 20, 1944, now abandoned and insert instead Serial No. 528,771 filed March 30, 1944, now Patent No. 2,420,729; column 6, line 14, list of references cited, for Jan. 1, 1906 read Jan. 1, 1925;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 5th day of April, A. D. 1949.

THOMAS F. MURPHY,

Assistant Uommz'ssianer of Patents.