US3363969A - Dyeing and light stabilizing nylon yarns with sulfonated dyes; sterically hindered phenols, and alkylnaphthalene sulfonates with or without other ultraviolet light absorbers - Google Patents

Description

United States Patent M DYEING AND LIGHT STABILIZING NYLGN YARNS WlTH SULFONATED DYES; STERI- CALLY HHNDERED PHENGLS, AND ALKYL- NAEHTHALENE SULFONATES WITH OR WITHUUT OTHER ULTRAVIOLET LIGHT ABSURBERS Joseph Aloysius Brooks, Wilmington, DeL, assignor to E. I. du Pont de Nemours and Company, Wilmington,

DeL, a corporation of Delaware No Drawing. Filed Feb. 12, 1964, Ser. No. 344,204

11 Claims. (Cl. 817) ABSTRACT OF THE DISCLQSURE Nylon yarns are dyed with a solution of a water soluble sulfonated acid dye, a 2,6-dialkyl-4-phenyl phenol, an alkylor aralkyl-substitute naphthalene sulfonic acid ammonium or alkali metal salt. In addition, ultraviolet light absorbers, such as hydroxyphenyl-benzotriazole, hydroxybenzophenone, or aromatic substituted acrylonitrile can be used in the solution.

This invention relates generally to textile fibers and, more particularly, to a process for dyeing nylon yarns.

It is well known that streaking occurs in acid-dyed fabrics constructed with synthetic linear polyamide yarns, especially with continuous filament polyarnide yarns. Therefore, the level-dyeing disperse dyes are broadly used for nylon fabrics; but not all disperse dyes have acceptable lightfastness. With those disperse dyes that provide acceptable dye lightfastness, a severe problem in fading results because of the N0 and the O conventionally in the air. Level dyeing can be accomplished with acid dyes that are chemically stable to N0 and 0 by using anionic leveling agents, but such acid dyeing processes do not produce lightfast fabrics. In the acid dyeing of carpets, an additional problem exists in the fugitive stain from the jute backing, and this problem is evidenced by both streakiness and insufiicient lightfastness.

The principal object of this invention is to provide superior level-dyed polyamide yarns.

A further object of this invention is to provide nylon yarns that are level-dyed, lightfast, and stable to gaseous atmospheric conditions that are recognized to fade disperse-type dyes.

Other objects will appear hereinafter.

These and other objects are achieved in a process for dyeing polyamide yarn in a dye bath containing (1) sulfonated, water soluble, acid dyes with molecular weight less than 850; (2) an anti-oxidant which is a phenolic compound of the formula a naphthalene compound Patented Jan. 16, 1968 wherein R is a monovalent substituent radical selected from the group consisting of propyl, isopropyl, butyl (normal, secondary and tertiary), amyl (normal, secondary and tertiary), and aralkyl, m is 1-3 and R" is a monovalent radical selected from the group consisting of NH and alkali metal cations, each of the substituent radicals -R and -SO R" being attached at one of positions 1-8.

1n the preferred process embodiment, the aforementioned dye bath also contains (4) a p-hotostable, ultraviolet light absorber, said absorber being a member of one of the classes consisting of hydroxyphenylbenzotriazoles, hydroxybenzopheno-nes, and aromatic substituted acrylonitriles, and being readily absorbed by polyamide yarn.

The phenolic compound is readily absorbed by polyamide yarns, remains substantially colorless during the dyeing process, and remains color-stable after dyeing. The bulky alkyl groups, R and R have generally at least 3 to 8 carbon atoms and are branched at the carbon atom alpha to the phenol ring. The preferred compound is 2,6-di-tert-butyl-4-pheny1 phenol. The phenolic compound is preferably added as an emulsion.

The examples illustrate the advantages of the process in the dyeing of p-olyamide yarns, particularly in dyeing finished goods (such as carpets) containing nylon yarns and in dyeing polyethylene oxide (PEG) modified nylon yarns and fabrics. It is known that the tendency of filaments prepared from synthetic linear polyamides to ac quire undesirable static charges has been overcome and that soil resistance has been enhanced by blending with the polyamide at least 2% by weight of a polyethylene oxide (PEO), prior to forming filaments thereof. After dyeing, however, the color of yarns and fabrics prepared from PEG-modified nylon filaments still can weaken at process embodiment wherein the dyes, antioxidant, level ing agent and ultraviolet light absorber are combined in a dye bath. Examples I and VI show the preferred method of adding the antioxidant as an emulsion, resulting in unexpectedly superior level-dyed, lightfast, carpeting that is stable to atmospheric conditions. The second example shows the benefits of having only the acid dyes, leveling agent and phenyl-phenol in the dye bath. Example III shows unsatisfactory lightfastness obtained when the antioxidant is omitted. The fifth example shows the unsatisyarn is dyed by the process of this invention. All percentages, except Where otherwise noted, are based on carpet weight. Also, for convenience, the approximate Metric System equivalent of the English units have been given in parentheses.

EXAMPLE I Approximately 700 square yards (585 square meters), weighing 1340 pounds (600 kilograms), of jute-backed carpeting comprising 21 ounces per square yard (496 r grams/square meter) of face nylon is tufted with 3700- al. in U.S. Patent 3,005,251. Said carpeting is placed in a denier, 204-trilobal, continous-filament, jet bulked yarn, melt-spun from poly(hexamethylene adipamidefiiake. The yarn is jet bulked with the jet taught by Hallden ct nominally 15-foot-wide (4.56 meters) beck containing approximately 5500 gallons (21,000 liters) of a scouring bath which is an alkaline aqueous solution at 130 F. (54 C.) comprising 1) 0.1% Antifoam B (a silicone emulsion to reduce foaming), (2) 0.25% the condensation product of 15-25 mols of ethylene oxide with 1 mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, and 0.15% the sodium salt of the sulfate ester of either a long-chain, fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, (3) 0.75 NaOH, and (4) 1.5% of a solution of 30 weight parts H and 70 weight parts H O. This solution is raised to 140 F. (60 C.) and then 0.25% sodium dichromate is added and next, the temperature of this resultant dichromate solution is raised to 200 F. (90 C.) at a rate of 3 F. (1.66 C.) per minute. Then, the scouring bath is dropped, the beck is filled again with 5500 gallons (21,000 liters) of water at 130 F. (54 C), and this rinse bath is run for 10 minutes and then dropped.

The heck is refilled, this time with a bath of 5500 gallons (21,000 liters) of water and the carpeting is leveldyed in said beck according to the following procedure.

(1) Set the dye-bath at not more than about 80 F. (27 C.) and add 1.75 pounds (794 grams) of Antifoam B.

(2) In a separate piece of equipment, provide an aqueous solution of 11.2 pounds kilograms) the ocsodium sulfonate of disec-buty1 naphthalene, and 35 pounds (16 kilograms) of phosphoric acid; and then syphon this solution to the heck to attain a pH of about 3.3 in said beck.

(3) Dissolve in 50 gallons (189 liters) of water in another piece o-f equipment, a mixture of 0.25% CI. Acid Brown [sodium P-[4-(diethylarnino)hydroxy-l-naphthylazo]benzenesulfonate], 0.04% CI. Acid Red 57 [sodium 6 amino-5 [O-(ethylphenylsulfamoyl)phenylazo] 4-hydroxy-2-naphthalenesulfonate], and 0.041% C.I. Acid Blue 40 [0.1. 62125], to make a cocoa shade, and continuously add this solution to the heck over a period of minutes.

(4) Run this bath for 15 minutes at 80 F. (27 C.) and then raise the temperature to 140 F. (60 C.) at a rate of 3 F. (l.66 C.) per minute.

(5) Dissolve in about 12 gallons (45 liters) of water in a separate piece of equipment, 70 ounces (2 kilograms) of NaOH, 1.2 ounces (34 grams) of the condensation product of 15-25 mols of ethylene oxide with one mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, and 7 pounds (3.2 kilograms) of 2-(2-hydroxy-5'-metl1yl phenyl)benzotriazole. This solution is brought to a boil to form the sodium salt of the benzotriazole and then diluted to about 40 gallons (150 liters) of solution to reduce solution temperature to about 120 F. (49 C.).

(6) To the 140 F. (60 C.) bath (Step 4), continuously add the cooled solution of Step (5) to the heck over a period of 15 minutes. The pH of the dye bath in the beck is now about 3.7.

(7) Raise the dye-bath temperature to 180 F. (82 C.) at arate of 3 F. (1.66 C.) per minute.

(8) Add 13.4 pounds (6 kilograms) of 2,6-di-tertbuty1-4-phenyl phenol as an emulsion. Said emulsion is made up by first preparing 61 parts by weight of A and 39 parts by weight of B. Part A consists of 24 parts by weight of 2,6-di-tert-butyl-4-phenyl phenol, 36 parts by weight of toluene, and 1 part by weight of oleic acid. Part B consists of parts by weight of a 10% ammonium caseinate solution in water, 1.2 parts by weight sodium salt of technical lauryl alcohol, 1 part by weight KOH, and 6.8 parts by weight water. Then A is added to B with high speed agitation to provide a stable, water-dispel-sable, antioxidant for the dye bath.

(9) Add approximately 4 pounds (1.8 kilograms) of phosphoric acid to attain a pH of approximately 3.7 in the dye bath.

(10) Raise the temperature of the dye bath to 205 F. (96 C.) at the rate of 3 F. (166 C.) per minute.

(11) Dye for 1 hour at a temperature as close as possible to 205 F. (96 C.).

(12) Drop the dye bath, rinse the carpeting well, extract the rinse water, and dry the carpeting at about 280 F. (138 G). Then latex-back the carpeting at 285-300 F. (140-150 C.).

This carpeting is observed to be attractively level-dyed, substantially streak-free, and desirably unstained by the jute-backing. Then it is tested for lightfastness by exposure to Florida sunlight for 45 sun hours. The Gray Scale rating, 4, resulting from such an exposure to sunlight, indicates a sufficiently small shade change to rate the carpeting to have good lightfastness. For an exposure to Florida sunlight for 65 sun hours, the Gray Scale rating is between 4 and 3. In the Gray Scale (described in Standard Methods for the Assessment of the Color Fastness of Textiles by the Society of Dyers & Colorists, 19 Picadilly, Bradford, Yorks, England) 5 denotes no shade change and 1 denotes the greatest (an unacceptable amount) shade change. A unit increase in the Gray Scale denotes a two-fold improvement in lightfastness.

The dyed carpetin of this example is also tested for chemical fading. For testing stability in 0 the dried and finished dyed carpeting is placed in a commerical ozone, oven maufactured by Ozone Research & Equipment Corporation, 3840 N. 40th Ave., Phoenix, Ariz. Said oven exposes the carpeting to 10 parts of O in one hundred million parts of air for 120 hours at 95 F. (35 C.) and between and relative humidity. The Gray Scale rating, 4, resulting from such an exposure to 0 indicates a sufiiciently small shade change to rate the dyed carpeting to be stable to atmospheric conditions wherein O is present. For testing stability to N0 the dried and finished dyed carpeting is tested following the American Association of Textile Chemists and Colorists Test No. 23-1962 for 2 cycles and then the Gray Scale rating is 4, to indicate sufficiently small shade change to rate the dyed carpeting to be stable to atmospheric conditions wherein N0 is present.

EXAMPLE II 152 grams of face nylon yarn is used to prepare jutebacked, tufted carpeting comprising 22 ounces per square yard 520 grams/square meter) of said face nylon. Said yarn is 3700-denier, 240 trilobal, continuous-filament, jetbulked yarn, melt-spun from poly(hexamethylene adipamide)flake. The yarn is jet-bulked with the jet taught by Hallden et al. in US. Patent 3,005,251. Said carpeting is placed in a laboratory beck containing an alkaline aqueous solution comprising 0.25% the condensation product of 15-25 mols of ethylene oxide with 1 mol of either a longchain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, and 0.15% the sodium salt of the sulfate ester of either a long-chain fatty alcohol or a mixture of fatty alcohols each containing 12-18 carbon atoms, and 0.75% NaOH. Said alkaline aqueous solution is heated to F. (54 C.) at a rate of about 3 F. (1.66 C.) per minute and then 1.5 of a solution 30 weight parts of H 0 and 70 weight parts H O is added to the laboratory beck. The resultant solution is now heated to F. (60 C.) at a rate of about 3 F. (1.66 C.) per minute. Optionally, 0.25 sodium dichromate is added at this point. Heating is continued at a rate of 3 F. (1.66 C.) per minute up to a temperature of 200 F. (93 C.). Then the scouring bath is dropped, and the carpeting is rinsed twice with water.

The laboratory heck is refilled with water, and the carpeting is level-dyed in said laboratory beck according to the following procedure:

(1) Set the dye bath at not more than 100 F. (38 C.)

and add 0.75% of the u-sodium sulfonate of di-sec-butyl naphthalene, and 1% 2,6-di-tert-butyl-4-phenyl phenol in 30 cc. acetone.

(2) Run this bath for 5 minutes; then slowly add as a mixture 0.5% CI. Acid Brown 10, 0.06% CI. Acid Red 57, and 0.05% CI. Acid Blue 40.

(3) Run this bath for an additional 5 minutes at 100 F. (38 C.) and then add diluted phosphoric acid dropwise for about 15 minutes to attain a pH of 4.0 and then bring the bath to a boil at a rate of about 2-3 F. (1.1 1-1.66 C.) per minute.

(4) Run this bath for 45 minutes and then add cc. of a 10% phosphoric acid solution to obtain a pH of about 3.1.

(5) Complete the dyeing for one hour at a temperature as close to the boil as possible.

(6) Drop the dye bath, rinse the carpeting twice with warm water, extract, and finally dry the carpeting at about 275 F. (135 C.).

This carpeting is observed to be substantially streakfree and is tested for lightfastness by exposure to the light of a Xenon arc in air in an Atlas Xenon Weather- Ometer (Model 60-WR) to simulate 80 sun hours. The Gray Scale rating for the carpeting of this Example II is 2.

EXAMPLE III Example II is repeated except that in Step 1 of the leveldyeing procedure, instead of 2,6-di-tert-butyl-4-phenyl phenol, 0.15% the condensation product of -25 mols of ethylene oxide and 1 mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms is added. The Gary Scale rating observed in the carpeting of this Example III is 1 for simulated 80 sun hours.

EXAMPLE IV Example II is repeated except that no 2,6-di-tert-butyl- 4-phenyl phenol is added in Step (1), and instead in Step (5 of the level-dyeing procedure, 1.5 on weight of yarn of 2,6-di-tert-butyl-4-phenyl phenol in 30 cc. of acetone is added dropwise and then 0.5% 2-(2'hydroxy-5'-methyl phenyl)benzotriazole in 30 cc. acetone is also added dropwise. Also, in Step (5 the dyeing is 30 minutes. The Gray Scale rating observed in the carpeting of this Example IV is 3 for 80 simulated sun hours.

EXAMPLE V Example II is repeated except that instead of 2,6-ditert-butyl-4-phenyl phenol, 1% on weight of yarn of 2,6- di-tert-butyl-4-methyl phenol is added in Step (1). Fur thermore, the dyeing in Step (5) is completed in only 30 minutes. The Gray Scale rating observed in the carpet of this Example V is 1 for 80 simulated sun hours.

EXAMPLE VI 159 Grams of face nylon are used to prepare carpeting similar to the carpeting prepared for Example I1, and this carpeting is scoured and rinsed in a laboratory beck in the same manner as is the carpeting for Example II. Then the laboratory beck is refilled with water, and the carpeting is level-dyed in said laboratory beck according to the following procedure:

(1) Set the dye bath at not more than 100 F. (38 C.), add 0.15% the condensation product of 15-25 mols of ethylene oxide with 1 mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, and then add 18 grams of dispersed emulsion in 20 parts of water at 170 F. (77 C.). Said dispersed emulsion is made as follows:

A melt at 221 F. (105 C.) is made of a mixture of 24 grams of 2,6-di-tert butyl-4-phenyl phenol, 12 grams of 2-(2-hydroxy-5'-methyl phenyl)benzotriazole, and 12 grams of the condensation product of l-S mols of ethylene oxide with 1 mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty 6 alcohols each containing 12-18 carbon atoms. Twelve grams of said melt is added, with mixing, to 48 grams of a 15% Water solution (cooled in water to 50 F. (10 C.)) of the a-sodium sulfonate of di-sec-butyl naphthalene to form a thick creamy dispersed emulsion.

(2) Run this bath for 10 minutes; then add slowly as a mixture 0.5% CI. Acid Brown 10, 0.06% CI. Acid Red 57, and 0.05% CI. Acid Blue 40.

(3) Run this bath for an additional 10 minutes at F. (38 C.) and then add 2% acetic acid to attain a pH of 4.5 and then bring the bath to a boil.

(4) Boil for 45 minutes and then add phosphoric acid solution to obtain a pH of about 3.0.

(5) Continue the dyeing for about 30 minutes more at a temperature as close to boil as possible. The pH is then about 3.2.

(6) Drop the dye 'bath, rinse the carpeting twice with Warm water, extract, and finally dry the carpeting at about 275 F. C.).

This carpeting is observed to be substantially streakfree, and is tested for lightfastness as is the dyed carpeting of Example II. The Gray Scale rating for the carpeting of this Example V1 is 3.

EXAMPLE VII Three griege skeins of 3700 denier, 204 trilobal, crosssection filaments, zero twist, semi-dull luster, bulked yarn constructed of filaments spun from a 95/5 melt blend of poly(hexamethylene adipamide)/polyethylene oxide ether glycol of 20,000 molecular weight are scoured for 20 minutes at F. (60 C.) in a 30:1 aqueous bath previously set at 80 F. (27 C.) with 0.06% of the condensation product of 15-25 mols of ethylene oxide with one mol of either a long-chain fatty alcohol containing 12-18 carbon atoms or a mixture of fatty alcohols each containing 12-18 carbon atoms, and 0.2.5 tetrasodium pyrophosphate. After rinsing, one of the skeins is leveldyed in a dye-bath according to the following procedures:

(1) Set the dye bath, containing the skein, at not more than 80 F. (27 C.) with 0.75% the OL-SOdlllIn sulfonate of di-sec-butyl naphthalene, and 0.75% Lyocol HW, a leveling agent which is an anionic, aromatic sulfonate.

(2) Run this bath for 10 minutes and then add 0.5% of 2-(2-hydroxy-5-methyl phenyl)benzotriazole, and 1% 2,6-di-tert-butyl-4-phenyl phenol dissolved in 30 cc. acetone.

(3) Run this bath for 10 minutes and then slowly add, as a mixture, 1% Cl. Acid Brown 1 0, 0.12% CI. Acid Red 57 and 0.08% Ct. Acid Blue 58 [0.1. 62125] dyes.

(4) Run this bath for an additional 10 minutes at 80 F. (27 C.).

(5 Slowly add sufiicient acetic acid (concentrated) to give a pH of about 4.5.

(6) Raise the bath temperature to 130 F. (54 C.) at the rate of about 1 F. C.) per minute and then run this bath again for 10 minutes.

(7) Raise the bath temperature to F. (71 C.) at the rate of about 1 F. C.) per minute.

(8) Raise the bath temperature to 200 F. (93 C.) at the rate of about 2 F. (1.11 C.) per minute, adding 1.5% phosphoric acid at the end of 30 minutes.

(9) Dye for 1 hour at a temperature as close to 200 F. (93 C.) as possible.

(10) Cool back to 180 F. (822 C.) slowly, rinse well, extract, and then dry the yarn at 280 F. (138 0).

Another skein is similarly dyed except that no ultraviolet light absorber is added in Step (2), although the phenyl phenol is present. The third skein is similarly dyed except that Step (2) is omitted.

These three dyed and dried skeins are tested for dye light-fastness by exposure to the light of a Xenon arc in air in an Atlas Xenon Weather-Ometer (Model 60- WR) to simulate 80 sun hours. They are then compared with otherwise identical, unexposed skeins. The results are shown in the table below with a numerical rating according to the Gray Scale:

ultraviolet light absorber 2 Dyed with neither the ultraviolet light absorber nor the phenyl phenol 1 The above example indicates that the effect of the phenolic antioxidant and the ultraviolet light absorber is more than additive because, when they are both present, the improvement is more than twice the improvement due to the presence of the phenolic antioxidant alone.

As hereinbefore indicated, Example I specifies the preferred process embodiment wherein the ultraviolet light absorber is added to the dye bath in the form of a sodium salt with subsequent regeneration to the free phenol. The temperature is raised, and then 2,6-ditert-buty1-4-phenyl phenol is added as an oil-in-Water emulsion. Finally, the carpeting is rinsed, dried and latex-backed. Example VI illustrates another process wherein the antioxidant is in the form of an emulsion.

Examples II, IV and VII indicate that the process is likewise operable when the antioxidant is added in acetone. Example VII further illustrates the beneficial results obtained on PEO-modified yarns.

The process of this invention has utility for fabrics as well as for yarn, for bulked, as Well as for unbulked, yarn, for round, as well as for unround, filaments, and is particularly useful in dyeing carpets, rugs and upholstery, Whether or not the yarn is FED-modified.

The preferred leveling agent is the aforementioned asodium sulfonate of di-sec-butyl naphthalene. Also operable are the B-sodium sulfonate of disec-butyl naphthalene, the a-sodium sulfonate or" di-isopropyl naphthalene, the ,B-sodium sulfonate of di-isopropyl naphthalene, the u-sodium sulfonate of diamyl naphthalene, the aor 6- sodium sulfonate of triamyl naphthalene, the B-sodium sulfonate of diamyl naphthalene, the (X.- or fi-sodium sulfonate of tributyl naphthalene, the lx-sodium sulfonate of dibenzyl naphthalene, the fl-sodium sulfonate of dibenzyl naphthalene, and 2,6-di-tert-butyl-4-phenyl phenol sulfonate. The operable range of leveling agents for the purpose of this invention is (based on yarn weight) from 0.25% to 2%, and 0.75% is the preferred concentration.

The operable range of antioxidants for the purpose of this invention is 0.25% to 2% (preferably 1%) based on yarn weight. The preferred antioxidant is 2,6-di-tert-butyl- 4 phenyl phenol.

2-(2'-hydroxy-5-methyl phenyl)benzotriazole is the preferred ultraviolet light absorber for the process of this invention, and it has an absorption maxima on nylon of 350-360 m Other ultraviolet light absorbers which are also operable with nylon in the dye bath, are those that are also photostable, also have a useful absorption maxima on nylon, and are members of the classes comprising hydroxyphenylbenzotriazoles, hydroxybenzophenones, and aromatic substituted acrylonitriles. Examples of such other operable light absorbers are 2,4-dihydroxybenzophenone and the ethyl ester of 2-cyano-3,3-diphenyl acrylic acid. Ultraviolet light absorbers for this invention are operable in the range of 0.25 to 1.5% (preferably 0.5 to 0.75%) based on the yarn Weight.

The operable acid dyes for this invention include C.I. Acid Yellow 29 [01. 18900], C.I. Acid Brown 10, Cl. Acid Red 57, Cl. Acid Blue 23 [CI 61125], C.I. Acid Blue 40, Cl. Acid Blue 41 [01. 62130], 0.1. Acid Blue 58, Cl. Acid Yellow 17 [C.I. 18965], and C.I. Acid Red 37 [C.I. 17045]. The concentration of dyes is not critical, but a practical operating range is about 0.05 to 3.00%, based on yarn weight. It has been found that acid dyes with molecular weights more than about 850 do not disperse to a satisfactory degree of uniformity.

The polyamides comprehended by this invention are synthetic, linear polyamides characterized by recurring amide linkages as an integral part of the polymer chain. These polyamides are produced by condensation of monoamino, monocarboxylic acids or their amide-forming derivatives, or of diamine and dicarboxylic acids or their amide-forming derivatives. Examples of the first group are polycaprolactam and polyaminoundecanoamide. Examples of the second grou are poly(hexamethylene adiparnide), poly(hexamethylene sebacamide), poly(m-xylylene adipamide), poly(p-xylylene sebacamide), poly(2-methylhexamethylene adipamide), and the polyamide from bis(p-aminocyclohexyl)methane and sebacic acid. Copolyamides within or among these groups may also be employed. With these polyamides, there may be melt-blended 2% or more by weight of a polyethylene oxide. The polyethylene oxide ether glycols having a molecular Weight of at least 1000 are particularly suitable. Alternatively the polyethylene oxide may have, as end caps, either one or two radicals of oxyhydrocarbon such as methoxy, ethoxy, phenoxy, dodecyl phenoxy, nonyl phenoxy, and the like. The capped polyethylene oxides, especially when capped by aromatic radicals, should have a molecular weight of 600 or more. The molecular weight and concentration requirements are imposed by the necessity that enough of the oxide be added to provide a two-phase conductive system, i.e., to render the fiber antistatic. PEO compounds which have ends reactive with the polyamide are excluded since they do not form such a two-phase system. These polyamides, with or without polyethylene oxide, may also contain conventional polyamide additives such as delusterants, pigments, plasticizers, adjuvants to increase dye ability, etc. Typical additives are disclosed in US. Patent Nos. 2,205,722, 2,510,777, 2,887,462, and 2,345,533.

This application is a continuation-in-part of application Ser. No, 315,362, filed Oct. 10, 1963.

It is apparent that many variations and modifications of the disclosed process may be accomplished without departing from the spirit of the present invention which is accordingly intended to be limited only by the scope of the appended claims.

What is claimed is:

1. A process including the steps of dyeing, rinsing and drying nylon yarns, said dyeing step comprising heating said yarn in a bath containing (1) sulfonated, water-soluble, acid dyes with molecular weight less than 850; (2) 0.25 to 2.00% by Weight, based on yarn Weight, of a phenolic compound of the formula wherein R and R are alkyl groups of sufficient bulkiness to sterically hinder the phenol group; (3) 0.25 to 2.00% by weight, based on yarn weight, of a member of the class of leveling agents consisting of 2,6-di-tert-butyl-4-phenyl phenol sulfonate and a naphthalene compound of the formula wherein R is a monovalent substituent radical selected from the group consisting of propyl, isopropyl, normal butyl, secondary butyl, tertiary butyl, normal amyl, sec ondary amyl, tertiary amyl, and aralkyl, m is 1-3 and R" is a monovalent radical selected from the group consisting of NH,+ and alkali metal cations, each of the sub- 9 stituent radicals -R and SO R" being attached at one of positions 1-8; and (4) 0.25 to 1.50% by weight, based on yarn weight, of a photostable, ultraviolet light absorber, said absorber being a member of one of the classes consisting of hydroxyphenylbenzotriazoles, hydroxybenzophenones, and aromatic substituted acrylonitriles.

2. The process of claim 1 wherein the phenolic compound is added as an emulsion.

3. The process of claim 1 Where the nylon yarn is a PEO-modified nylon yarn.

4. The process of claim 1 wherein the phenolic compound is 2,6-di-tert-butyl-4-phenyl phenol.

5. The process of claim 4 wherein the 2,6-di-tert-butyl- 4-phenyl phenol is added as an emulsion.

6. A process including the steps of dyeing, rinsing and drying nylon yarns, said dyeing step comprising heating said yarn in a bath containing (1) sulfonated, water-soluble, acid dyes with molecular weight less than 850; (2) 0.25 to 2.00% by Weight, based on yarn Weight, of an emulsion of a phenolic compound of the formula wherein R is a monovalent substituent radical selected from the group consisting of propyl, isopropyl (normal butyl, secondary butyl, tertiary butyl, normal amyl, secondary amyl, tertiary amyl), and aralkyl, m is l-3 and R" is a monovalent radical selected from the group consisting of NH4+ and alkali metal cations, each of the sub- It) stituent radicals R' and -SO R" being attached at one of positions 1-8.

7. The process of claim 6 wherein said phenolic compound is 2,6-di-tertbutyl-4-phenyl phenol.

8. A process including the steps of dyeing, rinsing and drying nylon yarns, said dyeing step comprising heating said yarn in a bath containing (1) sulfonated, water-sold ble, acid dyes with molecular weight less than 850; (2) 0.25 to 2.00% by weight, based on yarn weight, of an emulsion of 2,6-di-tert-butyl-4-phenyl phenol; (3) 0.25 to 2.00% by weight, based on yarn weight, of the a-sodium sulfonate of di-sec-butyl naphthalene; and (4) 0.25 to 1.50% by Weight, based on yarn weight, of 2-(2-hydroxy- 5 -methyl phenyl)benzotriazole.

9. The process of claim 8 wherein the nylon yarn is a PEO-modified nylon yarn.

10. A process including the steps of dyeing, rinsing and drying nylon yarns, said dyeing step comprising heating said yarn in a bath containing (1) sulfonated, water-soluble, acid dyes with molecular weight less than 850; (2) 0.25 to 2.00% by weight, based on yarn Weight, of an emulsion of 2,6-di-tert-butyl-4-pl1enyl phenol; (3) 0.25 to 2.00% by Weight, based on yarn Weight, of the a-sodium sulfonate of di-sec-butyl naphthalene.

11. The process of claim 10 wherein the nylon yarn is a PEO-modified nylon yarn.

References Cited UNITED STATES PATENTS Oct. 15, 1961.

D. Schmidlin, The Preparation and Dyeing of Synthetic Fibres, pp. 152-159, 163 and 227-232, pub. Apr. 1, 1963 by Chapman and Hall, Ltd., London England.

Strobel, American Dyestuif Reporter, pp. 583-588, Aug. 7, 1961.

DONALD LEVY, Primary Examiner.