US2436059A - Discharge printing of colored cellulose acetate fabrics with the aid of an intermediate thiocyanate treatment - Google Patents

Description

Patented Feb. 17, 1948 DISCHARGE PRINTING OF COLORED CELLU-.

LOSE ACETATE FABRICS WITH THE AID- OF .AN INTERMEDIATE THIOCYANATE TREATMENT :Herbert G. Scull and James G. McNally, Rochester, N. Y.', assignors to Eastman Kodak Company, Rochester, N. 2.,

Jersey a corporation of New No Drawing. Application March 4, 1943,

Serial No. 478,005

8 Claims. (01. 8-64) This invention or discovery relates to the discharge-printing of colored textile fabrics made of or containing an organicderivative of cellulose yarn. More particularly, ourinvention or disally similar to the discharge style described above except that thedischarge'paste used to destroy the color of the coloredfabric'contams a dye which colors the area of the fabric which is discovery is directed to the discharge printing of charged by the discharge print paste. The dye colored textile fabrics 'made from an organic used in the discharging paste, of course, must derivative of cellulose yarnor yarns or made not be unduly affected by the discharge paste. from an organic derivative of cellulose yarn or In both types of discharge printing the color or yarns in admixture with yarn from materials dye wlthwhich the textile fabric is colored must such as. viscose, cotton, cuprammonium silk and 10 be one capable of being discharged. 4 The disregenerated cellulose. Our invention or discovcharge paste, by like token, must be one which ery is particularly directed tothe discharge printis capable of destroying the color of the textile ing of coloredtextile fabrics made of or containfabric when appropriatelyapplied thereto. ing cellulose acetate. Generally speakinggthe' discharging of colored .It is an object of our invention or discovery textile fabrics is efiected through the use Of reto provide a process for improving the sharpness ducing agents. As is well known to those skilled 0 i ndt e clearnes's of the discharged area in the art of textile printing, the reduction disof colored organic derivative of cellulose textile charge process based on sodium formaldehydefabrics subjected to discharge printing operasulfoxylate or potassium formaldehyde-sulfoxy; tions. A particular object of our invention or late, in general use for the'discharging of colored discovery is to provide a satisfactory commercial cotton, viscose rayon, cuprammonium silk, silk process for the production of. white and color and wool textile fabrics, has not proven satisfacdischarges in the same pattern on colored textory for producing clear cut designs on colored tile fabrics containinganorgan'ic derivative of organic derivative of cellulose textile fabrics, cellulose yarn. Another object is to provide a such as cellulose acetate.- With certain coloring process for producing white and color discharges matters, regardless of the concentration of dye on colored organic derivative of cellulose tex used on the ground shade,'the discharged areas tile fabrics by the use of an acid; reducing dishave a tendency to bleed out or halo around the charge printing paste and an alkaline vat dye edges of the printed desi n- Th 1 m noticecolor paste. Other objects will appear hereinable when the fabricis' aged in. sufficient moist after. steam to give good resultswith'vat' colors em- Typical organic derivatives of cellulose include ployed i frp tt s as il um nathe hydrolyzed as we'll as'the 'unhydrolyzed celtion colors, where both' white and colored. oblulose organic acidesters such as cellulose ace- 'J'm S are de n e a 'PE tate, cellulose formate, cellulose propionate or 'It'has been proposed heretofore to overcome cellulose u y ate a d t hyd o yzed as well the above-mentioned difiiculty ofjspreading or as the unhydrolyzed mixed organic acid esters haloing ofthe' discharge'fareas and to increase of cellulose such as cellulose acetate-propionate, the clearness and sharpness of the discharged cellulose acetatc butyrate and the cellulose ethers areas by incorporati g n t discharge paste such as methyl cellulose, ethyl cellulose or benzyl 40 various acids and swelling agents of an acid nacellulose. ture. These methods have met with some suc- Discharge printing processes can be classified cess when the disch'arged dyed style of printunder two types known as discharged dyed ing has been carried out and also where a loose style and color oncolor discharge printing. style of color on color discharge has been em- In the first mentioned type the textile fabric is ,5 ployed. By a loose style is meant a type of colored with a coloring matter capable of being printing known to those skilled in the art as the discharged and -a discharge paste is applied in use of colors which are fugitive to light or washthe areas where it is desired to decolorize the coling and which are, therefore, limited in their ored material. By appropriate treatment the application. V Y areas where the discharge paste has been ap- In an efiort to secure satisfactory discharges plied are left either white or a lighter shade on colored cellulose acetate textile fabrics, the than the original coloring or dyeing while the use of calcium thiocyanate or barium thiocyanate areas where no discharge paste has been applied (U. S. Patent 1,651,639), zinc thiocyanate (U. S. are'left-unchanged. ,1 I Patent 1,981,907) or guanidine thiocyanate (U. Color on color dischargecprintln'g. is'gener- 5 8. Patent 1,931,108) in the'discharge paste-to produce pastes of an acid character, have been proposed. These pastes apparently give the best results of the prior art discharge printing pastes. However, in producing fast colors with dyes, such as the vat dye'colorsj which require an alkaline medium, on colored textile fabrics which are to have a pattern containing both white and colthe medium of a printing paste alone.

ored discharges, it has been found that a carryover from the above-mentioned acid thiocyanate discharge printing pastes gets on the printing roller applying the vat dye color in an alkaline medium. When the carry-over from the acid print paste comes in contact with: the; alkaline vat dye color, a scum forms ontheprinting roller applying the vat color. This scum, which is apparently due to the formation of carbonates and oxides by interaction between the acid discharge,

paste and the alkaline vat dye color, causes smearing of the pattern because the doctor blade is unable to clean properly. Be cause smearing occurs after; he-immune en ra i n n s n as e in.eperatie ut-are et y l how me. t m th d ha Re r e ed ommer i y p actical.

While our imprgvcddlfifihfirge printing process is c b e enerall o the: disch e in i g of colored textile fabrics made of or containing anorganic derivative of; cellulose yarn, it is of greatest utility, for the productio of both white and. colored discharges; on such colored textile fabrics wherein. the; discharging is eifectedunder acid conditions one rollenprintingmachine. The textile fabrics, for. example, can-be prepared-from one or more organicderivativeof cellulose yarns, or they can-be prepared fromone or. more organic derivative-of cellulose y'arnsin admixture with viscose, cotton or cuprammonium silk yarns, for example.

We have discovered thatthe objects'of our invention ordiscoverycanbe accomplished by incorporating an inorganic thiocyanate into the textile fabric prior to the printing operation. Ordinarily the-inorganic thiocyanate will be incorporated in thetex'tlle fabric after the fabric has been colored but prior to'tl'le printing operation. The manner of-incorporatingthe inorganic thiocyanate or the time of its incorporation are immaterial so long as the inorganic thiocyanate is present the colored textile, fabric prior to the printing operation. Thus, the inorganic thiocyanate maybe incorporated inthe textile fabric by immersion padding or spraying, for example. That is, the colored textile fabric may be immersed inasq utifiii pifthe inorganic thiocyanate, padded with the solution or sprayed with the solution. Thecol'ore'dtextile fabric co'ntaine ing the inorganic thiocyanate i'ssdriedor substantially dried prior to the printing operation.

Inorganic thiocyanates that can be employed include, for example, calcium thiocyanate, zinc thiocyanate, aluminum-,thiocyanate, manganous thiocyanate, magnesium thiocyanate, barium thiocyanate, sodium thiocyanate and potassium thiocyanate/ For purposes of clarityit is here noted that the thiocyanates-are also known as sulfocyanides. Thus, calciu rn' thiocyanate and calcium s l flfi amde ar one and the same compound. The use of an acid thiocyanate, such as the first sixthiocyanates named above. is genml a an a eous.

As-previouslydndicated; the advantages of our invention or discovery, are. greatest when both white andcoloredidischargespn the colored dyed textile fabricate-desired .andzthe. discharging is effected under acid conditions. However, we have found that material advantages are obtained by incorporatingan inorganic .thiocyanate into the dyed textile fabric prior to printing, rather than applying the thiocyanate through Specifically, the clearness of the discharged area as well asthe sharpness-of the discharged area is ordinarily improved't; wo very important advantages. Again, in, the case of screen printing, our

invention or discovery possesses the added advantage that considerably more pieces of goods (-rough1y,- 2 to 3. times more) may be printed before thescreit-is rendered unsuitable for use.

This advantage is'obtained because the thiocyanatein; the usual printing pastes attacks the screen, which is ordinarily made from pure silk,

nylon or vinyl acetate-vinyl chloride copolymers, whereas if the thiocyanate is incorporated in the colored textile fabric it has little or no effect on the screen, The use of an acid inorganic thiocyanate-is'- preferred; by us'be'cause we have found that'theresults obtained using the acid inorganic thiocyanates are, generally speaking, superior to the results obtained when a neutral thiocyanate such as sodium thiocyanate or potassium thiocyanate is used.

Advantageously,when a colored organic derivative of cellulose textile fabric is treated in accordance with out inventionv or discovery the inorganic thiocyanate is incorporated into the colored textile fabric in conjunction with an appropriate swelling agent. Theuse of asuitable swelling agentaidsinsecuring gooddischa'rge of the color fromjcolored organic derivative of cellulose textilefabrics. Suitable swelling gents, include, for examplaorganic polyhydric alcohols such as glycerol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol and thiodiglycol. The high-boiling water-soluble organic swelling agents named areindicated to be illustrative and not limitative as other sub. stances which effctswelling, such as mono-N -n-butyrylethanola'mine and disalicylethanolamine' in the order named appear to-be best swelling agents'for celluloseacetate.

The amounts of the inorganic thiocyanate which should be incorporated into the colored textile fabric vary so widely that definite limits cannot be given. The amount to be'used depends, for example, upon. the nature of the fabric, the weave of the cloth,the size of the filaments, the dyestuff employed, the depth of the dyeing the speed of the printing machine, the depth of the engraving and the amount of padding liquor left in the fabric after padding and before drying. For the foregoing reasons it will be apparent that definite limits on the amount of the inorganic thiocyanate to use cannot be given. However, for each specific case the proper amount can be readily determined by those skilled in the art. The examples given hereinafter illustrate suitable amounts of the inorganic thiocyanates.

Similarly n0 definite limits on the amount of the swelling agent that can be used can be given. The amount to be used will vary, for example, depending on the factors named in connection with the inorganic thiocyanates. However, the proper amount to use in a given case can be readily determined by those skilled in the art and is illustrated by the examples given hereinafter.

The present invention or discovery fills a definite need in the printin art. By means of it organic derivative of cellulose (especially cellulose acetate) textile fabrics, colored-with dischargeable dyes, can be successfully discharge printed commercially. Again color on color discharge printing of cellulose acetate textile fabrics, so far as we are aware, is made commercially possible for the first time. Also in the case of discharged dyed style printing clearer and sharper defined patterns are obtained. Likewise, where screen printing is employed the use of our invention or discovery also permits considerably more pieces of goods to be printed before thescreen is rendered unsuitable for use. The following-examples illustrate the invention or discovery:

EXAMPLE 1 A fabric composed approximately of 50% cellulose acetate and 50% viscose rayon by weight was dyed by the single bath method in the customary manner with /3% of 2,4-dinitro-fi-monoethyl. sulfoneamidebenzeneazo (1,6') 1' ,Bn dihydroxypropyl-7-methyl-1,2,3,4 tetrahydroquinoline having the formula:

(based on. the weight of the acetate content) and 17 of a commercial preparation of Colour Index Dye 406 (based on the weight of the viscose rayon) dried and impregnated with a solution of the following proportions:

Ounces Zinc thiocyanate solution (sp. gr. 1.30) con- The textile fabric was then passed straight thr'oughithe nipof a two-roll padding machine 6. with the pressure on the squeeze rollers adjusted so as to allow the textile fabric to retain about 96%of its weight of the above solution. The textile fabric was then carefully dried in a net drier and then printed on a roller printing ma.- chine with the discharge pastes made up in the proportions indicated hereinafter. The discharge pastes are applied by separate rollers, the White Discharge Paste being applied first.

White discharge paste Ounces Textile gum, solubilized Gum Karaya containing 20% solids 5 Sodium formaldehyde-sulfoxylate 100%.. 3 Thiodiglycol 1.6 Water '3 Vat color discharge paste Ounces Colour Index Dye 1217 (commercial prep- After printing the textile fabric was dried in the usual manner and then padded on a regular printing machine with a milled stippled roller with a solution containing 3 oz, of 100 volume hydrogen peroxide per gallon of 4% gum tragacanth paste (this mixture was freshly made up) The padding solution was applied only to the face of the printed material in the usual manner and the adjustment of the engraving and set of the machine were made so as to allow not over a 12.5% pick-up on the weight of the textile fabric. The material was thencarefully dried in the usual manner and aged in a vat ager for a period of 6 to 8 minutes; The printed and aged textile fabric was then developed in the usual manner for vat colors and then dried. A sharp White and orange discharge was obtained on a bright blue ground.

Example 1. A sharp white and orange discharge was similarly obtained on a bright blue ground.

EXAMPLE 3 A fabric composed approximately of 50% cellu lose and 50% cuprammonium silk by weight was treated in accordance with the procedure described in Example 1. A sharp white and orange discharge waslikewise obtained on a bright-blue ground. 1

A fabric composed of 50% by weight of cellu lose acetate and 50% by weight of regenerated cellulose can similarly be treated'in accordance with the procedure described in Example 1 to ob tain a sharp white and-orange discharge on a blue-ground. Cellulose acetate -propionate or' dellulosie' acetate butyrate; for. exafiip1e,"can be substituted for the cellulose acetate' of the fabrics bf 'Example 1, 2' a'nd 3 and the procedurede scrib'edin Examble 1 carried out to obtain sharp white and orange dischargeson a bright blue ground. It 'will be understood, of course; that cellulose acetate propidnate oe' cellulo'se acetate butylate, for example, can alsobe Substituted for cellulose acetate in the examples which follow EXAMPLE 4 A fabric containing approximately 50%:-by weight of cellulose-acetate and 50 -;byweight viscose rayon is dyed a tomato red: shade iwith of d-nitrobenzeneazofld')-2-methyl-4' -difl-hydroxyethylaminobenzene having the formula:

CHzCHzOH and /4a% of 2-methoxy=5 ehlorobenzeneazo- (1,2')-5'-monomethy1-1',3'-cyclohexadione havme the-formula:

based onthe weight of thecellulo'se acetate con tent, and /g% of a commercial preparation of Prototype "D'ye' -79, /64%' a commerc al preparatibrrof Prototype- Dye'24-and- /s'2% oifa-ooinniercial preparation of Prototype Dyef '19 based; on 'theweight of theviscose rayomcontent; The textile fabric was dyeddireetlybythe usual single bathmethod; dried and then impr gnat d with asolution having the following proportions:

7 Ounces Aluminum thiocyanate solution "containing 22% "or aluminum thlocyan'ate by "weight tspgg'r. 1.18); 6.98 frriiodigiycoi Water 112 After printing the textile fabric'with the printing paste just described, the textile fabric- -was dried in the usual manner,- then aged for 8-10 minutes in-a' chimney ager at 1101-106" C rinsed and'dried. White objects which arever-ysharp in-detail are obtained on a redground.

The aboveprocedure was carried out without EXAMPLE Fabrics containing approximately 50% weight 'ofcellulos'eacetat'e and 50% by -w'ei'ght cotton: 50%by weight of cellulose a'cetat'e and 60% by weight cupramnion'iuinsilk canf be substitutedfor the fabric of Example 4'and the procedure'of Example 4"car ried'out to'obtain white objects which -are verysharpin detail-on a-red l5 ground'i'n each instance.

EXAMPLE '5 6 Mean; ert l ,ia r c ose w 'nsrpr cellulose acetate was dyeda light brown color emplaying .the'single bath method-in the customary r' annerjwitharnixture (by weight on the fabric) of 0.5%' of 4-nitrobenzeneazo (1,1 -3-ch1o ro,-

fl' rnono-bhydroxyethylaminobenzene, 0.5% of {2;4 -dinitro 6' xnonoethylsulfone-amidebenaene- 57): M 1 h d QX y t 1 2 ,3,l tetrahydroquinolineand 0.25% of 4-nitroben z ene'azo (L 1') -2-n1ethyl-4-di-- p 'hydroxye ethylaminobenzene. Following the dyeing operationifthetextile fabric was dried and then treated with a solution made up in-the following proportions: 1

zine th i'dcyanate solution containingfl44% thiocyanate by weightls'p. gr. 1.30)

I ounces" 6 Irithyle ne g1ycol do 4 water; "quarts" 3.5

l v v O s odiui'n formaldehyde sulfoxylate 3 Water. v s: Textile gum solubilized Gum Karaya containing 20% solids 10 After printing the textile'f'abiic with the printing paste just described the textila'fabric was dried in the usual manrier, then aged far 8-10 minutes in a chimney ager at 101 166 0., rinsed and dried. A white object which'was very sharp in detail was obtained on a light brown ground.

The textile fabric of the example dyed as dee r ewb a a o be subi t 0 rlri lie wn eti n in ac o d wi th r cedure described in Example 1,; except that the pine thiocyanate znixture described 'above is employed instead of that of'theexample. A white and orange discharge on a brown ground is obtained.

EXAMPLE '7 A taffeta textile fabric composed wholly of 'cellulo'se'acetatewas dyed 'a light brown color employingthe dye mixture of Example fi. Fol lowing: the d'yeing operation; the textile fabric .was dried and then treated with a solution made up inthe following proportions:

Zinc thiocyanate solution containing 44% zinc thiocyanate by weight (sp. gr. 1.30)

textile fabric was then carefully dried in a net drier and simultaneously printed on a roller printing machine with the discharge paste made up in the proportions indicated hereinafter,

White discharge paste Ounces Textile gum solubilized Gum Karaya containing 20% solids Sodium formaldehyde sulfoxylate 100% 3 Thiodiglycol 1.6' Water 3' After printing, the textile fabric was dried-in the usual manner and then padded ona regular printing machine with a milled stippled roller' with a solution containing 3 oz. of 100 volume hydrogen peroxide per gallon of 4% gum tragacanth paste (this mixture was freshly made up). The padding solution was applied only to the face of the printed material in the usual manner and the adjustment of the engraving and set of the machine were made so as to allow not over a 12.5% pick-upon the weight of the textile fabric. The material was then carefully dried in the usual manner and aged in a vat a'ger for a period of 6 to 8 minutes. The printed and aged textile fabric was then developed in the usual manner for vat colors and then dried. Av

white discharge was obtained'on a light brown ground. I 1

The colored cellulose acetate textile fabric of the example can also be screen printed in'ac-j cordance with the procedure described in Exampie 6 to obtain white objects which are sharp in detail on .a light brown ground.

Exaurm 8 A textile fabric containing approximately by weight of cellulose acetate propionate and 50% by weight cotton and a textile fabric con-' A white object which was very sharp taining approximately 50% by weight of cellulose acetate propionate and 50% by weight cupram-- monium silk can be substituted for the textile fabric of the example and subjected to the idenamounts of various inorganic thiocyanates which.v

.110 can be used to treat the colored textile fabrics indicated herein in accordance with the process "of our invention or discovery.

Percrntr l11111- organ 0 0- Inorganic thiocyanate Spr. Gr. Oz. cyanate By Weight Mauganous thiocyanate solid) 4.68 66 Bar1um thiocyanate solid) 3. 78v 81 Magnesium thiocyanate l. 28 6.18 41 alcium thiocyanatel. 22 6. 60 34 Sodium thiocyanate..- solid :1. 22 C. P. Potassium thiocyanate' solid 1.46 O. P.

Any of the above thiocyanates can be added to 112 oz. of water and 2 oz. of thiodiglycol to form suitable mixtures for treating the colored textile fabric prior to the discharge printing operation. The inorganic thiocyanate padding solution or mixture can be made up to contain only the inorganic thiocyanate compound as indicated above but generally a swelling agent is included. Suitable amounts ofthe swelling agent to be incorporated intc'the padding solution have been indicated in the examples. It will be clearly understood that the thiocyanates tabulated above can be substituted for the thiocyanates of the examples toobtain the same or substantially equivalent results. Also it is to be clearly understood that the process of our inven--' tion or discovery is not limitedto the use of the particular swelling agents disclosed in the examples as. generally similar amounts of the other swelling agents indicated herein can be employed.

'Other inorganic thiocyanate solutions that can be employed fortreating or padding the colored textile fabric prior to the discharge printing op eration are listed hereinafter. j

EXAMPLI'A .Ouncesj 1 Aluminum thiocyanate "solution (sp. gr.

i 7-; Water a Y 112 mm: B

. p Ounces Magnesium thiocyanate solution (sp. gr. 1.28)' r 61 Water .4 112 Y ,Exmmc 5 I Ounces Calcium thiocyanate solution (sp. gr. 1.22) I I Sulfated fatty alcohol I 0. @Water v 112 Exmnn D i m j i Ounces Manganou's thiocyar'i'ate a Triethyleneglycol ..1 5 Salicylic acid 1 ater i l 112 l .EXMIPLEE Ounces Magnesium thiocyanate solution (sp. gr. 1.28) 6 Citric acid 3 Water v .112

' ExmLsF i I Ounces Aluminum thiocyanate "solution (sp. gr.-

,1.30). Magnesium thiocyanate solution (sp. gr. --j-....-'- '.-.;.-A----'----- -i 3 Water. 1 112 anemone The amounts of the' lnorganic thiocyanates and swelling agents indicated above are'not'critical as greater or lesser amounts "canbe employed. In the claims the expression a sub- 'stantialamount has been used with reference itothe amount of the inorganic thiocyanate or swelling agent incorporated into the colored textile fabric. This expression means onlythat an efi'ective amount, that is, .an amount sufficient to exert a jperceptible beneficial effect is employed-as compared to the result obtained withj out the use of'ei-ther an inorganic thiocyanate or example. .As the combinations which canbe employed are obvious additional combinations have .been omitted as unnecessary. Similarly, one or more swelling agents can be employed in conjunction with the inorganic thiocyanates. To illustrate, thiodiglycoland'triethyleneglycol, triethylene glycol and diethylene glycol or thiodiglycol, glyceryol and tetraethyleneglyccl can be employed. Other combinations that can be em- .ployed are readilyapparent.

, As will be apparent to those skilled in the art to which this invention or discovery is directed and asindicated hereinbefore, any dischargeable dye for the colored textile fabric can be employed in the process of the invention or discovery. Additionaldyes whose .dyeings can be discharged from cellulose acetate include, for'example, l-nitrobenzeneazo (1,1") -4-N-ethyl-4'- N-,8-hydroxyethylaminobenzene (Prototype Dye 244), 2,4-dinitrobenzeneazo (1,1')-2'-methyl-5'- methoxy 4'-N o dihydroxypropylaminobenzene, Prototype Dye 236 (4-nitrobenzeneazo -(1,'1') -2' -methyl-4-N,N-di-,s hydroxyethylami nobenzene) Prototype [Dye 238 (2-chloro-4-nitrobenzeneazo (1,1') -2 -rnethyl-4'-N,N-dip hy droxyethylaminobenzene) and Prototype Dye 242 (4-acetylaminobenzeneazo (1,1') -2'-hydroxy- 5'- methylbenzene). Similarly, many other dyes in addition to those specifically indicated can be used in the color on color" discharging op- =eration. To illustrate, Colour Index Dye 1217,

Prototype Dye 1'07, Flavanthrone, ColourIndex DyellSLColour-Index Dye 1101 and Colourindex Dye 1104 can be employed. The dyeslisted herein are merely illustrative as other dyes are known to those skilled in the art that can be employed. Finally, dyes (such as Prototype Dye 20, for example) other than those specifically disclosed can be used to produce dischargeable dyeings on viscose, cotton and cuprammonium 511k, for example. The particular dye or dyes employed constitute little or no part of the invention as any suitable 'known dyes orany suitable dyes developed in the future can be em: ployed. Colour Index or prototype numbers given" are those'given in the'l941 Year Book of-the American Association of TextileChem'ists and Coloris'tsf? In a few cases the prototype number does not appear in the book just referred to -and in those cases, the number appears, for example, in the 1941'Yearl3ook of the American Association of Textile Chemists and Colorists, Vol. XXI.

' The dischargeprintingpastes disclosed are .intended to-be illustrative and not limitative since,

12 within the teachingsof the invention, considerable variation can 'be :made in these-printing pastes as .is well known to those skilled in the art. The printing-pastes disclosed, however, have been found to be quite satisfactory.

The term dry as used in the claims is not intended to mean that the textile fabric must be entirely moisture-free. All that is required is :that .thefabric be relatively or substantially .dry. That is the fabric need be just dry enough that the printing operation or operations can be satisfactorily carried'out. Normally the fabric is quite dry. The amount of drying required for satisfactory operation in any given case can'be readily determined.

While our invention or discovery has been .described more particularly in connection with the discharge printing of .cellulose acetate-the most important member of the organic derivative of celluloseclass-it is applicable to the discharge printing of other organic derivatives of cellulose such as those named hereinbefcre. vAgain, while all regenerated celluloses have not been tested, it would appear that this general class of substances illustrated by viscose and cuprammonium silk, for example, can be present in the textile fabric.

The single bath method of dyeing referred to in the examples is well knownto thoseskilled in the art to which this invention or discoveryis directed. One satisfactory way of carrying out this method of dyeing is'to prepare a paste from an intimate admixture of the dye .or dyes to be employed with a dispersing or 'solubilizingagent and to add this paste to the dyebath. The dye paste can be prepared :from water and the mixture of dye and dispersing agent. We have found that a dyebath containing .25 parts by weight of-water to 1 part "by weight of cloth is very sat is'factory. Preferably a small amount of a wetting agent is also present in-the dyebath during the dyeing operation. 1% of 1% (by weight on the cloth) of sodium lauryl sulfate has been found satisfactory for this purpose. The dyeing operation is completed by subjecting the cloth to treatment in the dyebath at a temperature of 190 F. for 2 hours. It is to be 'clearlyunderstood, howeven that the single dye bath method of dyeing just described is illustrative and not limitative as many variations are possible.

We claim:

1. The process of discharge printing a colored organic derivative of cellulose textile fabric which comprises treating the colored textile fabric with an-acid inorganic thiocyanate whereby a substantial-amount of the acid inorganic thiocyanate is impregnated in the fabric, passing the textile fabric in dried condition to a roller printing machineand discharge printing the colored textile fabric containing the thiocyanate with an alkali metal .formaldehyde-sulfoxylate white discharge printing paste and an alkali metal formaldehydesulfoxylate vat color discharge printing paste whereby white and colored objects, wherein the color of the colored objects difiers from that of the colored textile fabric, are obtained'on the colored textile fabric.

2. The process of discharge printing a colored organic derivative of cellulose textile fabric which comprises treating the colored textile fabric with a solution of an acid inorganic thiocyanate and thiodiglycol, whereby a substantial amount of the acid inorganic thiocyanate and thiodiglycol is impregnated in the textile fabric, drying the textile fabric passlng the dried textile fabric to 13 a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate with an alkali metal formaldehyde-sulfoxylate white discharge printing paste and an al kali metal formaldehyde-sulfoxylate vat color discharge printing paste whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric. 3. The process of discharge printing a colored cellulose acetate textile fabric which comprises treating the colored textile fabric with an acid inorganic thiocyanate whereby a substantial amount of the acid inorganic thiocyanate is impregnated in the fabric, passing the textile fabric in dried condition to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate with an alkali metal formaldehyde-sulfoxylate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric.

4. The process of discharge printing a colored cellulose acetate textile fabric which comprises treating the colored textile fabric with a solution of an acid inorganic thiocyanate and thiodiglycol, whereby a substantial amount of the acid inorganic thiocyanate and thiodiglycol are pregnated in the textile fabric, drying the textile fabric and passing the dried textile fabric to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate with an alkali metal formaldehyde sulfoxylate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric.

5. The process of discharge printing a colored organic derivative of cellulose textile fabric which comprises treating the colored textile fabric with an acid inorganic thiocyanate and an organic swelling agent for the textile fabric, whereby a substantial amount of the acid inorganic thiocyanate and the organic swelling agent is impregnated in the fabric, passing the textile fabric in dried condition to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate and the organic swelling agent with an alkali metal formaldehyde-sulfoxylate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste, whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textil fabric, are obtained on the colored textile fabric.

6. The process of discharge printing a colored organic derivative of cellulose textile fabric which comprises treating the colored textile fabric with a solution of an acid inorganic thiocyanate and an organic polyhydric-alcohol swelling agent, whereby a substantial amount of the acid inorganic thiocyanate and the organic polyhydricalcohol swelling agent is impregnated in the fabric, drying the textile fabric and passing the dried textile fabric to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate and the swelling agent with an alkali metal formaldehyde-sulfoxyl ate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste, whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric.

7. The process of discharge printing a colored cellulose acetate textile fabric which comprises treating the colored textile fabric with an acid inorganic thiocyanate and an organic swelling agent for the textile fabric, whereby a substan tial amount of the acid inorganic thiocyanate and the organic swelling agent is impregnated in the fabric, passing the textile fabric in dried condition to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate and the organic swelling agent with an alkali metal formaldehyde-sulfoxylate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste, whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric.

8. The process of discharge printing a colored cellulose acetate textile fabric which comprises treating the colored textile fabric with a solution of an acid inorganic thiocyanate and an organic polyhydric-alcohol swelling agent, whereby a a substantial amount of the acid inorganic thiocyanate and the organic polyhydric-alcohol swelling agent is impregnated in the fabric, drying the textile fabric and passing the dried textile fabric to a roller printing machine and discharge printing the colored textile fabric containing the thiocyanate and the swelling agent with an alkali metal formaldehyde-sulfoxylate white discharge printing paste and an alkali metal formaldehyde-sulfoxylate vat color discharge printing paste, whereby white and colored objects, wherein the color of the colored objects differs from that of the colored textile fabric, are obtained on the colored textile fabric.

HERBERT G. SCULL. JAMES G. McNALLY.

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

UNITED STATES PATENTS Number Name Date 1,398,357 Briggs Nov. 29, 1921 r 1,651,639 Smith Dec. 6, 1927 1,874,176 Ellis Aug. 30, 1932 1,898,211 Penche Feb. 21, 1933 1,912,008 Powers May 30, 1933 1,931,108 Downing Oct. 17, 1933 1,957,491 Dreyfus May 8, 1934 1,963,121 Ellis June 19, 1934 1,972,137 Ellis Sept. 4, 1934 1,981,907 Downing Nov. 27, 1934 2,031,594 Dreyfus Feb. 25, 1936 2,037,013 Dreyfus Apr. 14, 1936 2,065,125 Dreyfus Dec. 22, 1936 2,289,461 Salvin July 14, 1942 FOREIGN PATENTS Number Country Date 285,942 Great Britain Feb. 23, 1928 Certificate of Correction February 17, 1948.

HERBERT G. SGULL ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 4, line 30, for the word out read our; line 41, for the word indicated read intended; column 7, line 4, for Example read Examples; column 11, line 71, for 1941 read 1944; 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 Ofiice.

Signed and sealed this 27th day of April, A. D. 1948.

THOMAS F. MURPHY,

lleg'atrmt Qommiasiager of Patents.