US2559787A

US2559787A - Colored cellulose esters and ethers

Info

Publication number: US2559787A
Application number: US682588A
Authority: US
Inventors: Olpin Henry Charles; House Kenneth Ronald; Wright John
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1945-07-20
Filing date: 1946-07-10
Publication date: 1951-07-10
Anticipated expiration: 1968-07-10

Description

Patented July 10, 1951 COLORED CELLULOS E ESTERS AND ETHERS Henry Charles Olpin, Kenneth Ronald House,

and John Wright, Spondon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application July 10, 1946, Serial No. 682,588. In Great Britain July 20, 1945 8 Claims. 1 This invention relates to the production of new dyes and the production of coloured fibres, foils, films and the like of cellulose acetate or other cellulose esters or ethers or of other fibreforming or film-forming materials which are,

soluble in organic liquids.

U. S. Patent 2,420,008 and U. S. Patent No. 2,393,652 describe the spinning of coloured fibres from solutions of fibre-forming materials, the said solutions being coloured with a dye having there-;

in a monovalent aliphatic radiele free from sulphonic and carboxylic groups, the said aliphatic radicle containing at least 8 carbon atoms united by carbon to carbon linkages, and particularly a monovalent aliphatic hydrocarbon radicle con-..

latter feature seems to be due to the fact that the dye is largely or Wholly in solution in the spinning solution and not merely suspended therein as in the case of a pigment. Solubility of the dye in the spinning solution is also of great advantage from the point of view of preparing homogeneous spinning solutions containing a definite and predetermined proportion of dye. Moreover when the dye is in solution the spinning solution is not likely to lose dye, as does a solution containing apigment, on passage through the filters which must usually precede v the spinning nozzles.

We have now found that coloured fibres,'foils, films and the like of fibreor film-forming materials soluble in organic liquids are very advan v tageously prepared with the aid of dyes having two or more aliphatic radicles containing a considerable number of carbon atoms for example 4 but preferably at least 6, 8 or more, united by carbon to carbon linkages. Dyes of thisseries possess high solubility in organic. liquids, notably in acetone, so greatly facilitating the preparation of coloured spinning solutions, e. g. of cellulose acetate. Further, fibres which are of exceptionally clear shade (and free from greasy appearance) can be obtained. Moreover coloured fibres possessing the excellent fastness to washing and like hot aqueous treatments of fibres coloured with the dyes specifically described in the above- 2 mentioned U. S. Patent No. 2,420,008 and U. S. Patent No. 2,393,652 can be produced.

The two aliphatic radicles are preferably attached directly to the same atom, for example a nitrogen atom or a carbon atom, though they may be attached directly to difierent atoms themselves attached to or forming part of the aryl dye nucleus. The aliphatic radicles may be attached to the same or different benzene rings of the aryl dye nucleus in the same or different ways and in any of the ways specified in U. S. Patent 2,420,008, and -U; S. Patent No. 2,393,652 for the attachment of the aliphatic radicle containing at least 8 carbon atoms. The following formulae indicate some of the ways in Which the two aliphatic radicles R1 and R2 may be attached to an aryl dye nucleus X.

Various saturated and unsaturated aliphatic radicles, preferably hydrocarbon radicles, may be present. Advantageously the suin of the carbon atoms in the two aliphatic radicles is at least 10 or 12 and preferably at least one of the radicles contains at least 8 carbon atoms. The radicles can be either primary, secondary, or tertiary, that is the carbon atom of the radicle at which attachment to the aryl dye nucleus is effected may be attached directly to 1, 2 or 3 other carbon atoms of the aliphatic radicle. Further the chains of carbon atoms in the aliphatic radicles may be straight or branched. Advantageously at least one of the aliphatic radicles contains a chain of at least 6 carbon atoms and preferably at least 8 carbon atoms.

Specific examples of aliphtaic radicles which may be present are:

n-Butyl, isobutyl, secondary butyl, n-amyl, isoamyl (CH3)2.CH.CH2.CH2-=, *n-heiiyl, n-octyl, 2-ethyl-n-hexyl, n-undecyl, n dodecyl, secondary dodecyl, n-pentadecyl-, n-hexadecyl, n-heptadecyl-, heptadecyl (9)-(din-octyl-methyl) noctadecyl, decylenyl CH2=CH.(CH2)8-, undecylnyl CH2=CI-I.(CH2)9-, heptadecylenyl CH3(CH2) 7.CI-I=CH.(CH2) v,

octadecylenyl CH3.(C1-Iz) 7.CH=CH(CH2) 3-, 8 9- dibrom-heptadecyL, 9 1 IO-dibrom-octadeoyl.

It is preferred that one of the aliphatic radicles should contain at least 4 carbon atoms and the otherat least 6 or 8 carbon atoms. Further it is desirable that the aliphatic radicles should be 1 free from sulphonic and carboxylic groups.

If desired the two aliphatic radicles can be attached directly to the same carbon atom and the latter attached to the dye nucleus. In this case the two aliphatic radicles and the carbon f atom to which they are attached may together be (Cal-I17) 2CH.CO.NH-

The following are examples of radicles comprising the two aliphatic radicles attached to the same carbon atom:

Di (n-o ctyl) -methyl n-Dodecyl-n-butyl-methyl One combination of the aliphatic radicles which has been found to give very good results consists of the two aliphatic radicles, preferably each containing at least 6 carbon atoms and advantageously at least 8 carbon atoms, for example 2 octyl radicles (e. g. n-octyl radicles) or two decyl or dodecyl radicles united directly to a nitrogen atom, for example a nitrogen atom of a sulphonamide group or of a carboxylic amide group. The presence of such a combination of aliphatic radicles leads to dyes of exceptionally high solubility in acetone, e. g. 5% or more, and with the aid of dyes containing such a combination of aliphatic radicles, coloured fibres can be produced which withstand very severe hot soaping treatments without material loss of the dye. A specific example of such a dye is l-aminoi-p-anisidinoanthraquinone-Z-carboxylic acid di-octyl-amide.

The dyes can be of various types, for example they can be azo dyes containing one, two or more azo groups, anthraquinone dyes, or dyes of the nitro-diarylamine series. The following are examples of dyes which can be made and used in accordance with the invention:

(1) 4-diethylamino-azobenzene 4' carboxylic acid di-octyl-amide (golden orange) (2) 4 (alpha alpha-di-n-octyl-acetylamino) -4'- dimethylamino-azo-benzene (yellow) (3) -stearoylamino-Z -hydr0xy-5' -dodecylazobenzene (yellow) (4) 4 (alpha: alpha-di-n-octyl-acetylamino) -2- hydroxy-5 -phenyl-azo -benzene yellow) (5) 2:6-dichlor 4 nitro 4' diethylamino-2- (alphazalpha di n octyl-acetylamino) -azobenzene (rubine) (6) 4-nitro-4' -diethy1amino-2 (alpha: alpha-din-octyl-acetylamino) -azo-benzene (red) (7) 4.- nitro-4-diethylamino-2'-(alpha-n-butylalpha n dodecyl acetylamino) -azo-benzene (red) (8) 4 (benzeneazo) -4-diethylamino-2'-(alpha:

' alpha di n-octyl-acetylamino) -azo-benzene (red) (9) 4 (benzeneazo) -4-diethy1amino-2-(alphan biityl alpha-n-dodecyl-acetylamino) -azo benzene (red) (10) Azo dye from diazotised p-nitraniline and 2 3-hydroxynaphthoic acid anilide-3 -sulphodioctyl amide (red) (11) I-amino 4 p-anisidino-anthraquinone-2- carboxylic di-octyl-amide (blue) (12) l-amino 4 o-anisidino-anthraquinone-2- carboxylic di-octyl-amide (blue) (13) l-amino-4-p-toluido-anthraquinone-2-carboxylic di-octyl amide (blue) (14.) 1phenylamino-anthraquinone-2-carboxylic di-octyl-amide (bluish red) (15) 1 cyclohexylamino anthraquinone-2-carboxylic di-octyl-amide (bright bluish red) (16) 1-methylamino-anthraquinone-2-carboxylic di-octyl-amide (bright bluish red) (17) 2-nitro-diphenylamine-4-carboxylic acid dioctyl-amide (clear yellow) (18) 2 nitro-4'-methoxy-diphenylamine-4-carboxylic acid di-octyl-amide (golden yellow) (19) 2:4-dinitro-diphenylamine 4 carboxylic acid di-octyl-amide (lemon yellow) (20) 2:4 dinitro a (alphatalpha-di-n-octylacetylamino) -diphenylamine (yellow) (2 1) 4 -cyclohexylamino -2 -nitro -benzene-4-carboxylic acid di-(n-octyl) -amide yellow) (22) 2 nitro diphenylamine 4 sulpho-di(noctyl) amide (pure yellow) (23) 2 nitro-4-methoxy-diphenylamine-4-sulpho-di(n-0ctyl) -amide (golden yellow) (greenish adequate to enable them to be used for colouring spinning solutions of cellulose acetate in acetone in such depth that the said solutions yield fibres of full shades when spun. In many cases it is possible to obtain acetone solutions of strength.

The dyes can be made in various ways. One method is to introduce the requisite aliphatic radicles into dyes containing amino groups, hy-

droxy groups or mercapto groups by-the action of appropriate alkylating or acidylating agents. Further, dyes containing carboxylic 0r sulphonic groups can be esterified with alcohols containing the requiste aliphatic radicles. Again a dye containing a reactive halogen atom can be subjected to the action of a secondary amine wherein the radicles attached to the nitrogen atom are aliphatic radicles of the required kind. In par-- ticular a dye containing a carboxylic chloride or sulphonic acid. chloride group may be allowed to react with a secondary amine of the kind indicated; for example the acid chloride of an azo dye containing a sulphonic or carboxylic group, or the acid chloride of a 1-amino-4-arylaminoanthraquinone-2-carboxylic acid or the acid chloride of a nitro-diarylamine carboxylic acid may so be allowed to react. The dyes numbered 1, 1'7, 18 19, and 21 are most conveniently made by this method which can also be used in the case of the dyes numbered 11, 12, and 13. In place of the acid chloride the acid bromide or a methyl, ethyl or other ester of the acid or even the acid itself can be used.

An alternative method is to make the dyes from appropriate components containing the requisite aliphatic radicles. For example, azo dyes can be obtained by coupling various coupling components (e. g. phenols, amines or pyrazolones) with diazo compounds of amines (including diazotized amino-azo-compounds), the coupling components and/or the diazotizable amines containing the requiste aliphatic radicles, for example in the form of a group -CO.NR1R2 of SO2.NR1R2 wherein R1 and R2 are the requisite aliphatic radicles. For instance azo dyes can be made by coupling a diazo compound with an N-dialkyl-aniline capable of coupling in paraposition to the amino group and having a dioctoyl-actyl-amino group as a substituent in meta position to the dialkyl amino group. The dyes numbered 5, 6, '7, 8, 9 and 10 in the above list are conveniently made in this manner.

Likewise, nitro-diarylamine dyes can be obtained by interaction of a halogen aryl compound and an amino-aryl compound at least one of which contains a nitro group and one or both of which carry the requisite aliphatic radicles, for example which carry the requisite aliphatic radicles attached to the nitrogen atom of a carboxylic amide or sulphonamide group.

Thus a nitro-halogen benzene carboxylic or sulphonic amide (particularly a 4-halogen-2- nitrobenzene carboxylic or sulphonic amide) of which the amide nitrogen carries the requisite substituents can be condensed with aniline or with a nuclear alkyl, alkoxy, halogen, amino, or acidylamino substitution product thereof, for example p-toluidine, p-octylaniline, p-anisidine, p-phenetidine, p-chloraniline, p-phenylene diamine, p-amino-acetanilide, p-(Z-ethylhexoylamino)-aniline, or mono-benzoyl-p-phenylene diamine. The dyes numbered 22 and 23 in the above list are very conveniently made in, this way and can also be used to produce the dyes numbered 17 and 18.

Anthraquinone dyes can be produced by subjecting a halogen anthraquinone containing a carboxylic amide or sulphonamide group of which the amide nitrogen carries the requisite aliphatic radicles to the action of ammonia or an alkyl, aryl, or aralkylamine so as to replace a halogen atom by an amino, alkylamino, cyclo-alkylaminoor arylamino group. Thus a 1-halogen-anthraquinone-2-carboxylic amide, or a 1 amino 4 halogen-anthraquinone-2-carboxylic amide, having the requisite aliphatic radicles attached to the amide nitrogen, may be caused to react with the ammonia or amine. The dyes numbered 11 to 16 in the above table are very conveniently made by this method.

The invention includes the dyes and their methods of manufacture.

The proportions in which the dyes are employed in the production of coloured fibres, foils, films, or the like can be within wide limits, for example from 0.5 to 2.5 percent based on the weight of the cellulose acetate or other fibreor film-forming material. Owing to the very high solubility in acetone cellulose acetate or other fibres or products containing very high proportions of the dyes can be produced via acetone solutions of the cellulose acetate or other materials, in which the whole of the requisite dye is in solution rather than in suspension.

Either wet or dry methods may be used for spinning into fibres the solutions of the fibreforming materials containing the dyes; thus fibres may be produced by spinning the solutions either into suitable evaporative atmospheres or into suitable coagulating baths. The invention is of special value in connection with the production of coloured cellulose acetate fibres by the spinning of acetone solutions of cellulose acetate.

The fibres may of course be assembled into yarns at the time of spinning as is commonly practised. Again the fibres may be out up into staple fibre and this, either alone or mixed with other textile fibres e. g. wool, silk, cotton or regenerated cellulose fibres, converted into yarn by the methods commonly employed for converting cotton or wool into yarns. Yarns consisting of or containing the coloured fibres of the invention can be formed into fabrics by weaving or knitting. The coloured materials produced in accordance with the invention may subsequently be topped with other dyes and particularly with direct dyeing dyes for cellulose esters or ethers, for example the water-insoluble dyestuffs of the nitrodiarylamine, azo, or amino-anthraquinone series, such as are extensively employed for the colouration of cellulose acetate materials. The topping colouring matter may be applied either uniformly or locally according to the eiTects it is desired to produce. The topping colours may be applied, for instance, in aqueous solution or dispersion according to their nature, or in solution in organic solvents. A single coloured material produced in accordance with the invention can thus be utilised to yield a range of materials of different shades.

The dyes of the present invention, like those of U. S. Patent 2,420,008, and U. S. Patent No. 2,393,652 have as a class little or no affinity for fibres of cellulose esters or ethers or other fibreforming materials when applied thereto in the ordinary way as aqueous dispersions. It has been be obtained: by' applying the. dyes. in: the form of.- The organic:

solutions in organic liquid media. liquid media can: be. those referred to in U'. S. Patent No; 23843001 inconnection. with the employment of arylamino-anthraquinones for colouring cellulose ester or ether materials. Again the dye liquids can beapplied to the; ma terials in any of the ways described in the said. patent.

The invention is of especial value in the production of coloured cellulose acetate fibres,.foils; films and the like. Similar coloured products. of other fibre-forming materials soluble. in organic liquids, particularly other cellulose esters or ethers, can be obtained likewise, for example of cellulose propionate, butyrate, aceto-propionat'e, aceto-butyrate, nitroacetate, and of methyl, ethyl and benzyl celluloses, and fibres and other products of polymerised vinyl compounds.

The invention is illustrated by the following examples the parts referred to being parts by weight.

Example 1 20 parts of 1-amino-i-brom-anthraquinone Z-carboxylic chloride is boiled for 8 hours: with 200 parts of benzene, parts of potassium-acetate, and 14.5 parts of dioctylamine. The benzene is distilled off and the residue stirred at 130 C. for 3 hours with 125 parts of para-anisidine, 15.6 parts ofpotassium acetate, and 3. parts of copper acetate. The l-amino--p-anisidinoanthraquinone-Z-carboxylic acid di-octyl amide is isolated by pouring into a mixture of 210 parts of concentratedhydrochloric acid and 250 parts of ice and boiling the oily precipitate first with a mixture of 60 parts of concentrated hydrochloric acid and 1000 parts of Water and then with a solution of 10 parts of sodium carbonate in 1000 parts of water; the product is finally-washed with water; Itis very soluble in acetone. By substituting o-anisidine or aniline for-the p-anisidine tl1e2corresponding' o-anisidinoand anilido-derivatives can be obtained;

By dry-spinning an acetone solution of cellulose acetate (25 percent strength) containing 1.5% of anyof the dyes based on the weight of the cellulose acetate, blue fibres of very good fastness tosoap scouring are obtained. A mixture of about equal; parts of the p-anisidino and o-anisidino compounds can be employed With'advantage, such a mixture having a remarkably high solubility in acetone.

1-phenylamino-anthraquinone 2 carboxylic aciddi-octyl amide and the corresponding l-cyclohexyla-mino compound can similarly be obtained from I-chlor-anthraquinone-2- carboxylic chloride, di-octylamine and aniline and cyclohexylamine respectively.

The 1-amino-4-p-anisidino anthraquinone- 2-carboxylic di-octylamideand the corresponding'o-anisidino and anilido compounds can likewise be obtained'though less advantageously by the action of di-octylamine on 1-amino-4-panisidino anthraquinone-Z-carboxylic chloride or the corresponding o-anisidino or anilido-derivative asrthe case may be.

In this example the di-n-octylaminecan be replaced by an equivalent amount of di-dodecylamine or of di-(2-ethylhexyl) -amine.

Example 2 6.1 parts ofi1-chloranthraquinone-2-carboxylic chloride is boiled for 2 hours with 50 parts: of benzene and 4;82"partsof di-octylamine. After distilling off the benzene, the residue is boiled under reflux with 60 parts of methylated spirit, 20 parts of aqueous methylamine solution (20%. strength), 5 parts of'potassium acetate and 0.1 part of copper acetate. The product is cooled, diluted with 400 parts water and the precipitated oil washed first with a little 10% sodiumcarbonate solution and then with water. The. oily 1-methylamino-anthraquinone-2-carboxylic aciddi-octylamide can then be dissolved in acetone and thesolution incorporated in a cellulose acetate spinning solution from which bluish-red fibres can be spun.

Example '3 27.4 parts of finely ground Z-nitro-i-carboxy- 4'-methoxy-di-phenylamine aremixed with 100. parts of toluene and 13 parts of thionyl chloride and the mixture-boiled under reflux until the nitro carboxy methoxy di phenylamine has passed into solution and no further acid fumes are evolved (usually about 1 hour) 24.1 partsof di-octylamine are then added and. the mixture refluxed for a further hour. After filtering, the tolueneis removed from the filtrate by distillation whereupon the 2-nitro-di-phenylaminee4- carboxylic acid di-octylamide remains as a thick oil which is extremely soluble in acetone.

2 :4-dinitro-diphenylamine -4' -carboxylic acid, and 2-nitro-di-phenylamine-2'-carboxylic acid can be converted into their di-octylamides in a similar manner; The di-octylamides are all very soluble-in acetone.

Example 4 parts. of 2-nitro-di-phenylamine-4-carboxylic acid is refluxed for 8 hours with 1000 parts of benzene and 58 partsof thionyl chloride; About three-quarters of the benzene is distilled off. through. a fractionating column at ordinary pressure. and the remainingbenzene distilled ofi under reduced pressure at a temperature below 100 C. The remaining carboxylic chloride is taken up in 500 parts of benzene, 100 parts of din-octylamine and 60 parts of potassium acetate added,.and the mixture refluxed for 8 to 1.0 hours; The. mixture is filtered and benzene removed from the filtrate by distillation under reduced pressure at a temperature below 100. C. 2-nitrodi-phenylamine-4-carboxylic acid di-octylamide remains as an orange oil,.very solublein acetone. By. dry spinning a 25% acetone solution of cellulose acetate. containing 1.5% of the dye (based on.the weight of the cellulose acetate) filaments ofa clear yellow shade are obtained. The coloured filaments are of very good fastness to light andare very resistant to hot soaping treatments, including the very vigorous treatments necessary to remove the gum from natural silk.

The di-n-octylamine in this example-can be replaced by an equivalent amount of di-dodecyl amine, di-(Z-ethylhexyD-amine or butyl-dodecylamine.

The 2e-nitro-di-phenylamine-4-carboxylic acid dioctylamide can also be obtained, though less advantageously, by heating the dioctylamide of3- nitro-4-chlor-benzoic acid with about6 times its weight of aniline at for 10 hours and isolating the product by cooling; to 70 C. andpouring into a mixture of 2 parts of concentrated hydro.- chloric acid and 3 parts of crushed ice. The product is then freed from traces of aniline by boiling with dilute hydrochloric acid (1 part of concentrated acid to 10 of water) and then with 1 percent sodium carbonate solution, finally be ing washed with water and dried.

Example 29.7 parts of the azo dye 4-diethylamino-azobenzene-4'-carboXylic acid (obtainable by coupling diazotised p-amino-benzoic acid with dieth-- ylaniline in dilute hydrochloric acid) is mixed with 100 to 150 parts of toluene and 13 parts of thionyl chloride and the mixture boiled under reflux, while stirring, until evolution of, hydrochloric acid ceases (usually about an hour). To the red solution is added 24.1 parts of dioctylamine and refluxing continued for a further hour, the liquid becoming more yellow in colour. The reaction mixture is filtered hot and the toluene removed from the filtrate by distillation, at first at ordinary pressure and finally under reduced pressure at a temperature not exceeding 120 C. The dye remaining is a dark orange viscous fluid, very soluble in acetone. By dry spinning a 25% acetone solution of cellulose acetate containing 1.5% of the dye (based on the cellulose acetate) filaments are obtained which are of a golden orange shade very resistant to hot soaping treatments.

Example 6 42 parts of 4-chlor-3-nitroben2ene-sulphonic' acid (ii-octylamide (obtainable by the action of dioctylamine on 4-chlor-3-nitrobenzene sulphochloride) is boiled for 5 hours with parts of aniline, 6 parts of sodium carbonate (anhydrous) and 250 parts of water. The red oil obtained is separated from the aqueous liquid and washed, first with water, then with dilute hydrochloric acid and finally with water. It is very soluble in acetone (more than 10%). By dry spinning a 25% acetone solution of cellulose acetate containing 1.5% of the dye (based on the weight of the cellulose acetate) filaments are obtained which are of a pure yellow shade very resistant to hot soaping treatments.

By replacing the aniline with an equivalent amount of p-anisidine the corresponding 4'-meth oxy-2-nitro-diphenylamine-4-sulphonic acid dioctylamide is obtained. By dry spinning a 25% acetone solution of cellulose acetate containing 1.5% of the dye filaments are obtained which are of a golden yellow shade very resistant to hot soaping treatments.

The dioctylamide compounds used in this example can be replaced by the corresponding didodecylamide compounds or the butyl-dodecylamide compounds with the production of dyes of very similar properties.

Having described our invention, what we desire to secure by Letters Patent is:

l. Fiber-forming materials, selected from the group consisting of cellulose ester and cellulose ethers, soluble in organic liquids, said fiber-formmg materials being colored with a dye which contains two monovalent aliphatic hydrocarbon radicles each of which contains from 8 to 18 carbon atoms united by carbon to carbon linkages, the chromophoric nucleus of said dye being free from sulphonic acid and carboxylic acid groups and being selected from the group consisting of the anthraquincne nucleus, the azo-benzene nucleus and the nitro-diphenylamine nucleus.

2. Fibers of an organic acid ester of cellulose soluble in organic liquids colored with a dye which contains two monovalent aliphatic hydrocarbon radicles each of which contains from 8 to 18 carbon atoms united by carbon to carbon linkages, the chromophoric nucleus of said dye being free from sulphonic acid and carboxylic acid groups and being selected from the group consisting of the anthraquinone nucleus, the ambenzene nucleus and the nitro-diphenylamine nucleus.

3. Cellulose acetate fibers colored with a dye which contains two monovalent aliphatic hydrocarbon radicles each of which contains from 8 to 18 carbon atoms united by carbon to carbon linkages, the chromophoric nucleus of said dye being free from sulphonic acid and carboxylic acid groups and being selected from the group consisting of the anthraquinone nucleus, the azobenzene nucleus and the nitro-diphenylamine nucleus.

4. Colored fibers according to claim 3 wherein the monovalent aliphatic hydrocarbon radicles are present in the dye in the form of a group -CO.NR1R2, wherein R1 and R2 are the aliphatic radicles.

5. Cellulose acetate fibers colored with an anthraquinone compound having an amino group in the 1-position, an arylamino group of the benzene series in the 4-position and in the 2- position a group CO.NR1R2, wherein R1 and R2 are monovalent aliphatic hydrocarbon radicles each of which contains from 8 to 18 carbon atoms linked by carbon to carbon linkages.

6. Cellulose acetate fibers colored with 2-nitrodiphenylamine having directly attached to a phenyl nucleus a group CO.NR1R2, wherein R1 and R2 are monovalent aliphatic hydrocarbon radicles each of which contains from 8 to 18 carbon atoms linked by carbon to carbon linkages.

7. Cellulose acetate fibers colored with 1- aminc-4-phenylamino-anthraquinone 2 carboxylic acid-dioctylamide.

8. Cellulose acetate fibers colored with 2-nitrodiphenylamino-4-carboxylic acid-dioctylamide.

HENRY CHARLES OLPIN. KENNETH RONALD HOUSE. JOHN WRIGHT.

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

UNITED STATES PATENTS Number Name Date 1,074,429 Gunther Sept. 30, 1913 1,903,600 Schweiter Apr. 11, 1933 2,083,308 Senn June 8, 1937 2,086,591 Whitehead July 13, 1937 2,101,323 Salzberg Dec. 7, 1937 2,105,519 Bodell Jan. 13, 1938 2,111,300 Senn Mar. 15, 1938 2,112,403 Krzikalla et al Mar. 29, 1938 2,145,580 Bley Jan. 31, 1939 2,193,151 Zerweck et a1 Mar. 12, 1940 2,241,251 Franklin May 6, 1941 2,288,531 Klarer June 30, 1942 2,294,968 Ellis et al Sept. 8, 1942 2,347,704 McNally et a1 May 2, 1944 2,388,663 Argyle Nov. 13, 1945 2,393,652 Olpin Jan. 29, 1946 2,420,008 Olpin May 6, 1947 2,420,453 Sutter May 13, 1947 FOREIGN PATENTS Number Country Date 501,913 Great Britain Mar. 8, 1939

Claims

1. FIBER-FORMING MATERIALS, SELECTED FROM THE GROUP CONSISTING OF CELLULOSE ESTER AND CELLULOSE ETHERS, SOLUBLE IN ORGANIC LIQUIDS, SAID FIBER-FORMING MATERIALS BEING COLORED WITH A DYE WHICH CONTAINS TWO MONOVALENT ALIPHATIC HYDROCARBON RADICALS EACH OF WHICH CONTAINS FROM 8 TO 18 CARBON ATOMS UNITED BY CARBON TO CARBON LINKAGES, THE CHROMOPHORIC NUCLEUS OF SAID DYE BEING FREE FROM SULPHONIC ACID AND CARBOXYLIC ACID GROUPS AND BEING SELECTED FROM THE GROUP CONSISTING OF THE ANTHRAQUINONE NUCLEUS, THE AZO-BENZENE NUCLEUS AND THE NITRO-DIPHENYLAMINE NUCLEUS.