US3667898A - Process for dyeing textile materials from organic solvent media - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS A METHOD OF DYEING TEXTILE FIBERS, PARTICULARLY IN THEIR WOVEN, YARN OR LOOSE MAT STATE, EMPLOYING DYESTUFFS DISSOLVED OR DISPERSED IN ORGANIC SOLVENTS, PARTICULARLY CHLORINATED HYDROCARBON SOLVENTS, FOR FIXING THE DYESTUFF INTO THE FIBER DURING THE PROCESS AND FOR RECOVERING SUBSTANTIALLY COMPLETELY THE SOLVENT FROM THE DYED FABRIC. THE TECHNIQUE OF THE PRESENT INVENTION EMPLOYS COMPOSITIONS COMPRISING HYDROPHOBIC ORGANIC SOLVENTS ALONE AND/OR IN ADMIXTURE WITH COSOLVENTS, SWELLING AGENTS AND FIXATIVES WHICH ARE COMPATIBLE WITH THE SOLVENT AND THE SOLUBLE AND/OR DISPERSIBLE ORGANIC DYESTUFFS. THE NOVEL METHOD COMPRISES APPLYING SOLVENT COMPOSITIONS OF DYESTUFFS TO TEXTILES, DIFFUSING

AND FIXING THE DYESTUFF INTO THE TEXTILE FIBERS WHILE MAINTAINING THE TEXTILE FIBER IN A ZONE FILLED WITH THE VAPORS OF A SOLVENT BOILING BETWEEN ABOUT 40*C. AND THE SOFTENING POINT OF THE FIBER, AND RECOVERING THE SOLVENT EITHER CONTEMPORANEOUSULY WITH SAID FIXATION OR IN A RINSE STEP FOLLOWING SAID FIXATION.

Description

June 6, 1972 s. BERGMAN ErAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA Fi led May 26, 1969 5 Sheets-Sheet 1 INVENTORS. 1 Sy/ves/er fiery/n 0/) BY R055 R. Dawson 9 TOR/VEY June 6, 1972 s. BERGMAN ETAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA Filed May 26, 1969 3 Sheets-Shoot 2 INVENTORS. dy/ves /er 5 erg/nan BY R055 R. DOM/$0? HTTORNEY June 6, 1972 BERGMAN ETAL 3,667,898

PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA Filed May 26, 1969 5 Sheets-Shut 5 INVENTORS. Q Qy/vesver ergman Q BY R055 R. Dawson \Q Q 0 o United States Patent Office Patented June 6, 1972 3,667,898 PROCESS FOR DYEING TEXTILE MATERIALS FROM ORGANIC SOLVENT MEDIA Sylvester Bergman, Midland, Micln, and Ross R. Dawson,

Buifalo, N.Y., assignors to The Dow Chemical Company, Midland, Mich.

Continuation-impart of application Ser. No. 670,433, Sept. 25, 1967. This application May 26, 1969, Ser. No. 827,620

Int. Cl. D06p 1/68 U.S. Cl. 8-94 19 Claims ABSTRACT OF THE DISCLOSURE The present invention concerns a method for dyeing textile fibers, particularly in their woven, yarn or loose mat state, employing dyestuffs dissolved or dispersed in organic solvents, particularly chlorinated hydrocarbon solvents, for fixing the dyestufi into the fiber during the process and for recovering substantially completely the solvent from the dyed fabric. The technique of the present invention employs compositions comprising hydrophobic organic solvents alone and/or in admixture with cosolvents, swelling agents and fixatives which are compatible with the solvent and the soluble and/or dispersible organic dyestuffs. The novel method comprises applying solvent compositions of dyestufis to textiles, diffusing and fixing the dyestufi into the textile fibers while maintaining the textile fiber in a zone filled with the vapors of a solvent boiling between about 40 C. and the softening point of the fiber, and recovering the solvent either contemporaneosuly with said fixation or in a rinse step following said fixation.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of our earlier filed application Ser. No. 670,433, filed Sept, 25, 1967, now abandoned.

BACKGROUND OF INVENTION Dyeing of textile materials, especially continuous rapid dyeing of such materials, often presents difficulties arising from the rate of diffusion of, and aflinity between dyestufi and fiber in an aqueous medium. Variations are noted among the several fibers, the dyestuffs, and the dyeing media.

Many of these difiiculties can be overcome by employploying special dyeing techniques to control diffusion of dye into the material. For example, linear polyester fibers can be dyed with dispersed dyes by application of superatmospheric pressure (pressure dyeing) or more rapidly and effectively by application of extreme temperatures, above 200 C. (Thermosol Process). The rapidity of the latter dyeing method makes it particularly Well adapted to continuous dyeing of polyester fiber. However, the

foregoing procedures have the disadvantage of requiring complex and costly dyeing equipment.

Further, it has been suggested to dye polyester fibers with dispersed dyestuffs in the presence of an organic solvent as a carrier, in an effort to shorten the time for dyeing and lower the temperature. The contention advanced being that the organic solvent swells the fiber or acts to decrease the intermolecular attraction forces of the fiber molecules and thus accelerates the dyeing. Use of such carrriers as solvents for the dye, a non-aqueous system, is generally not feasible commercially due to the large amounts of relatively expensive carrier required and lack of suitable recovery technology. On the other hand, use of a relatively small charge of such carriers in an aqueous bath containing a dispersed dye gives a relatively Weak dyeing or requires an excessively long dyeing time. Some of the disadvantages of the foregoing procedures have been overcome by dyeing linear polyester fibers in a dyebath composed of an aqueous emulsion of a solvent solution of dye stabilized by an emulsifying agent (Peirent et al., American Dyestutf Reporter, 49, 72 (1960)). This process, commonly referred to as the Solvent Emulsion Technique, requires only a relatively small quantity of costly solvent, since the external aqueous phase of the emulsion acts as a vehicle to distribute the small amount of dye-carrier solution among the fibers.

Numerous carrier compositions have been developed by the prior art but these, in general, have objectionable features which restrict their use in carrier dyeing of polyester fibers and especially as dye solvents in dyeing according to the Solvent Emulsion Technique. Some Wellknown effective carriers, e.g., diand trichlorobenzene are relatively poor solvents for dispersed dyestuffs. Because of the low solubility of these dyes in such carriers, large amounts of these carriers must be employed in Solvent Emulsion dyeing to dissolve the quantity of dyestufi required for deep dyeings. Inasmuch as dye absorption by a polyester fiber diminishes as the concentration of carrier in the Solvent Emulsion dyebath passes above a certain level, the depth of shade obtainable is severely limited. Moreover, the high concentrations of carrier required are prohibitively costly, adversely afiect the levelness of the .dyeing periods required for continuous dyeing were achieved only at temperatures of to 200 C.

Prolonged treatment in the dyebath is obviously unsuitable for continuous dyeing (for instance, dyeing of piece goods) and is costly from the viewpoint of time and energy consumed, while the higher dyeing temperatures have a degrading elfect both on the dye and the fiber.

Attempts to improve the dyeing of the aforementioned fiber with assistants and carriers often give unsatisfactory results, either through altering the properties of the fibers or by degrading the fastness of the dyes. Several processes using non-aqueous solvent media have been proposed for the purpose of decreasing the dyeing time, but the temperatures required in these process are high, in the range of 130 to 200 C. At these temperatures, many dispersed dyes decompose and it has been necessary to add a dye stabilizer to the dyebath. Also, these methods introduce the problem and cost of removing the solvent from the dyed fiber.

According to US. Pat. No. 3,098,691, the aforenoted problems were eliminated and the dyeing of polyester fiber with water-insoluble dyes free of ionogenic substituents was elfected neatly and rapidly by employing a dioxane dyebath at a temperature between 80 to 105 C. (preferably 95 to 100 C.) for a short period (usually less than minutes), whereupon the fiber is removed from the dyebath, rinsed with Water and dried.

An improvement in the known dyeing process is described in US. Pat. No. 2,999,002 in which textile materials are padded with aqueous suspensions of dispersed dyes and dried and thereafter treated with vapors of a chlorinated aliphatic hydrocarbon, notably trichloroethylene, and then rinsed in hot water and scoured with soap.

BRIEF DESCRIPTION OF INVENTION It has now been found that a fibrous material, either naturally occurring or man-made, can be dyed by treating the fibrous material whether it be in its woven, loose mat I or yarn state with a dye formulation (which may contain water) dissolved or dispersed in a vehicle consisting essentially of a volatile organic solvent; dilfusing the dyestutf into the fibrous material; simultaneously removing the solvent from the fibrous material and fixing the dyestulf into the fibers while maintaining the fibrous material in a zone composed primarily of the vapors, which may be superheated, of the solvent. Alternatively, the dyestulf is infused and fixed in the vapor zone of a solvent, the dyestufi solvent removed by scouring and the scouring liquor removed by introduction into a zone of vapors of the rinse liquor which may be superheated.

Commercially acceptable dyed fabrics have been obtained when the dyestuff is dissolved or dispersed in a volatile organic solvent having a boiling point above about C. but below the softening point of the fibrous material and below the decomposition point of the dyestulf. It may be advantageous to employ as a part of the dye formulation a fiber swelling agent which may be a cosolvent or a special agent. The process of the present invention can readily treat the fibrous material directly from the loom or weaving without the usual clean-up or scouring to remove lubricants and the like, with a dye formulation, infuse the dyestuff into the fiber, remove the solvent and fix the dyestuff when the fibrous material, treated with the dye formulation, is maintained in a zone of the vapors of the solvent for from about 10 to about 180 seconds, or longer. The vapor zone can conveniently be established by various means such as boiling solvent at the bottom of the zone, employing heated drums or cans within the vapor zone over which the fibrous material is passed, or the zone can be supplied with vapors, which may be superheated, from a source external of the zone. The escape of vapors from the vapor zone is prevented by providing a vapor condensing means which establishes the upper limit of the vapors and removes vapor in excess of that required to fill said zone. The condensed vapors may be re-used in the dye formulations and/or to generate the vapor in said zone. The fiber, after fixation of the dye and removal of excess solvent, may be rinsed to remove undesirable materials remaining after dyeing, such as dyeing assistants, etc., and dried in a vapor zone of a solvent of the character aforedescribed.

Alternatively, the process of the present invention can treat a fibrous material with a dye formulation which contains a solvent vehicle which has a boiling point above the boiling point of the volatile organic solvents. When such a solvent is employed, either as the principal or as the co-solvent, the steps to produce a satisfactorily dyed fiber consist of treating the fiber with the dye formulation, passing the wetted fiber into a zone of vapors of a solvent which has a boiling point between about 40 C. and the softening point of the fiber to diffuse the dye into the fiber. The so-treated fiber is then scoured in a solvent to remove the residual higher boiling solvent. The scouring solvent having a boiling point between about 40 C. and the softening point of the fiber, remaining on the fiber, is removed by passing the fiber into the vapors, preferably superheated, of a" solvent having a boiling point between about 40 C. and the softening point of the fiber. The higher boiling solvent is of course recoverable from the scouring solvent.

It is to be understood that substantially any fibrous material, commercially available, whether natural or manmade, or blends thereof, can be dyed in accordance with the present invention. Thus, the naturally-occurring fiber (such as wool and cotton) and the synthetic fibers (such as the polyarnides, the polyesters, the cellulose acetates, regenerated cellulose, the acrylics, polypropylenes and polyethylenes) can be dyed, as well as blends of these fibers, with a wide range of typical dyestuffs.

Exemplary of the dyes and suitable formulations for use in the present invention are adequately disclosed below.

Dispersed dye is intended to encompass the class of substantially water-insoluble dyes, this class having been originally introduced for the dyeing of cellulose acetate and usually applied from fine aqueous suspension.

C.I. Disperse Yellow 1 (C.I. 10345) C.I. Disperse Yellow 3 (C.I. 11855) C.I. Disperse Red 11 (C.I. 62015) C.I. Disperse Blue 26 (C.I. 63305 C.I. Disperse Blue 7 (C.I. 62500) C.I. Disperse Yellow (C.I.)

C.I. Dispersel Yellow 9 (C.I. 10375) C.I. Disperse Orange 11 (C.I. 60700) C.I. Disperse Red 19 (C.I. 11130) C.I. Dispersed Red 1 (C.I. 11110) C.I. Disperse Red 13 (C.I. 11115) C.I. Dispersed Red 3 (C.I.)

C.I. Disperse Blue 14 (C.I. 61500) C.I. Disperse Blue 19 (C.I. 61110) C.I. Disperse Blue 27 (C.I.)

C.I. Disperse Red 35 (C.I.)

C.I. Disperse Yellow 37 (C.I.)

C.I. Basic Orange 21 (C.I.)

C.I. Direct Red 31 (C.I. 29100) C.I. Acid Orange 86 (C.I.)

C.I. Acid Blue 40 (CI. 62125) C.I. Acid Blue 25 (C.I. 62055 C.I. Acid Red 209 (C.I.)

C.I. Acid Red 114 (CI. 23635) C.I. Basic Blue 21 (C.I.)

C.I. Basic Green 4 (C.I. 42000) C.I. Basic Red 13 (C.I. 48015 C.I. Basie Violet l4 (C.I. 42510) C.I. Basic Yellow 11 (C.I. 48055) C.I. Direct Yellow 12 (C.I. 24895 C.I. Direct Green 12 (C.I. 30290) C.I. Direct Blue 55 (C.I. 27940) Colour Index-The Society of Dyers and Colourists, The American Association of Textile Chemists and Colorists, 2nd ed., 1957.

Although the above classes of dyes, e.g.,, dispersed and solvent-soluble, are a preferred class, other known dyestuffs such as acid, basic metal containing and metalizable dyestuffs, can be employed equally well when the organic solvent is a chlorinated solvent, and/or the cosolvent employed is, for example, a dialkyl formamide, dialkyl acetamide, dialkyl sulphoxide, a glycol, a polyol, an alcohol or esters and ethers thereof. The dyestufi is employed in from about 0.1 to about 10 parts by weight and preferably from about 0.1 to about parts by weight, per 100 parts of solution.

In many instances, it is advantageous to employ fiber swelling or infusing agents to aid in the introduction and absorption of the dyestuff into the fiber as taught in the foregoing copending application of Ross R. Dawson. When such agents are deemed necessary as, for example, in dyeing the synthetic fibers, such agents which act to swell the fibers as ethylene carbonate and/or dialkyl acylamides can conveniently be employed. The fiber swelling or infusing agent is employed in amounts up to 0.1 part on the weight of fiber (OWF) equivalent up to parts by weight of agent per 100 parts by weight of dye formulation. Preferably this agent is employed in amounts of 0.01 to about 0.05 OWF (equivalent to about 0.1 to 5 parts per 100 parts by weight of dye liquor).

The organic solvents which can be. employed in accordance with the present invention are the aliphatic hydrocarbons, the aromatic hydrocarbons, and the chlorinated, brominated and fluorinated and mixed hologenated lower aliphatic hydrocarbons having from 1 to 4 carbon atoms, chlorinated aromatic hydrocarbons, lower alcohols, glycols and polyols, esters and ethers thereof and blends thereof, said polyols having average molecular weights from about 62 to 5000, the dialkyl formamides, dialkyl acetamides and dialkyl sulfamides, such as dimethyl formamide, dimethyl acetamide, and dimethyl sulfoxide, and mixtures thereof, both within the same class and among the classes. These solvents are liquid at room temperature and some will vaporize at above about 40 C. to just below the softening temperature of the fiber being dyed, the others, the higher boiling solvents, those nonvolatile at temperatures at or above fiber softening temperature, are removable in the scouring step. The pre ferred class of solvents are the aryl and alkaryl hydrocarbons, halogenated aromatic hydrocarbons, the petroleum naphthas, and the C to C chlorinated and fluorinated saturated aliphatic and olefinic hydrocarbons. Representative of the preferred class of solvents are benzene, toluene, trichlorobenzene, naphtha, carbon tetrachloride, methylene chloride, 1,1,l-trichloroethane, trichloroethylene, tetrachloroethylene (perchloroethylene), hexane, and mixtures of two or more of these. The solvent is employed in quantities sufiicient to dissolve or disperse the dyestuff, generally 90 to 99 parts by weight based on the total weight of the composition being preferred.

Included among these solvents are materials which in certain instances facilitate the dispersion, solution and/or infusion of the dyestulf. These materials are hereafter known as co-solvents. The materials which are suitable co-solvents are the alcohols, glycols, polyols (said glycols and polyols having an average molecular weight of from 62 to about 5000), the esters and ethers thereof, the aromatic and halogenated aromatic hydrocarbons, and the dialkyl formamides. While these co-solvents are also good principal solvents, they are more economically and advantageously employed as co-solvents. When so employed they are conveniently employed in amounts from 1 to 50 parts by weight based on the total composition. The cosolvents are either removed during primary solvent removal or in the scouring step which is generally employed although not critical if a co-solvent of high boiling character is not employed.

Dyestuff compositions which have been found useful in accordance with the present invention are those containing from about 0.001 to about 10 parts by weight of a dyestuff, about 99 to about 80 parts by weight organic solvent (which may contain 0 to about 50 parts by weight of a co-solvent) 0 to about 10 parts by weight swelling or infusing agent all based on 100 parts by weight of dyestuff composition. The preferred compositions contain about 0.1 to about 5 parts by weight of dyestuff, about to about parts solvent of which about 5 to about 10 parts is a co-solvent, and from about 0.0 to about 5 parts of swelling or infusing agent.

It is to be understood that other agents known to the dye industry and textile industry can be added to the dye solution to achieve recognized advantages and properties such as leveling in the finished fiber or textile Without departing from the spirit of the present invention.

It is to be further understood that dye formulations containing from about 2 to about 20%, preferably about 10% by weight water can also be employed in accordance with the present invention.

It is to be further understood that the same precautions known to those skilled in the art of dyeing should be taken relative to relating dyes to fibers.

DETAILED DESCRIPTION OF INVENTION The method of the present invention comprises padding, spraying, dipping, flooding or otherwise applying a dyestuff composition, which is a dye dissolved or dispersed in an organic solvent, of the character aforedescribed, preferably a chlorinated hydrocarbon solvent, onto a textile fabric, e.g., rug, carpet, upholstery fabric, thread, cloth or the like, and introducing the thus wetted textile into a zone of vapors of a volatile organic solvent, preferably the same solvent as employed in the dyestuif composition. While still within the zone of vapors, the textile is subjected to heat, introduced either by passing the textile over heated rolls, using microwave heating or introducing vapors, preferably superheated, into the vapor zone to contact the textile, or both, sufficient to raise the temperature of the fibers above that of the boiling point of the solvent. Any one or a combination of two or more methods may be employed. As a result of this operation, the solvent present on the fibers, if boiling at or below the temperature applied, is volatilized. Further, during and simultaneously with the passage of the textile material through the vapor zone the dye is diffused and fixed into the fiber. Thereafter, the textile is brought out of the vapors into the ambient atmosphere if the solvent is volatilizable, or may be scoured in a clean solvent, which is removed in like manner.

If it is advantageous to employ a solvent either as the principal solvent or as a co-solvent which boils above the softening point of the fiber, the solvent of course will not be removed during passage through the vapor zone, It is thus essential, after diffusion and fixation, to scour the high boiling solvent from the fiber with a solvent boiling below the softening point of the fiber and then remove the lower boiling solvent by passing the scoured fiber through a vapor zone of a like solvent.

Following this general technique, the examples set out in detail illustrate the present invention both as regards the dyestuff compositions and method which have been employed to successfully dye textile fabrics and fibers.

A textile cloth woven from a natural fiber, e.g., mohair or a synthetic fiber, e.g., a polyester blend'or an acrylic blend, was passed through a padding device by which means a dyestuif-solvent composition was introduced onto and into the textile. The so-wetted textile was passed into a zone filled with vapors of the solvent employed until fixation of the dyestulf had taken place and the textile was freed of solvent. The nature of the textile, the bath composition, time periods, etc., are given in the table below. The apparatus employed to carry out the process of the present invention to obtain the data below is described in the drawing and in particular detail in US. patent applications Ser. Nos. 505,520, filed Oct. 28, 1965, and 585,893, filed Oct. 11, 1966 both now abandoned, Method and Apparatus for Treating Fabric and the Like, by K. S. Surprenant, which description of apparatus and drawings are incorporated by reference into this description.

Dye Liquor, parts by weight total composition Dyestufi I (Josolvent Solvent and/or Amt., dyeing Temp Time, Type of fiber Kind OWF 1 Dyestufi Amt. Kind assistant sec.

Polyester. 0.1. disperse blue 27-..-- 0.5 0.5 89.5 perchloroethylene..-

} 1 1 4 Do.-. do 0. 5 50. 0 trlchloroethylene 5 37 45 Acrylic do 0. 6 0. 5 69. 5 perchloroethylene.. 2-3 121 35 Polyester. do.. o. 5 o. 5 se 5 '.--do 121 45 Nylon ()1. acid red #182. 0.2 0. 2 90 -.do o 2 i0 130 0 45. 0 RBY0ll. Direct red 8 0. 1 0. 1 0 hi hl m ylenen; J 5 130 5D 5 I4 45. 0 Mohair Basic yellow 13- 0.1 0.1 40. 0 -:;'..d0-... 28 145 50 8 I4 7 a 10. 0 Polyester. Dispersed violet #42 0. 8 0. 8 89. 2 do.... 1 Q 4 143 60 l 0. 4 Acryllc Basic yellow l3... 0. 4 0. 4 85. 0 do 121 0 1 OWF dye based on weight of fabric. 2 Parts ethylene glycol phenyl ether. 3 Dlmethyl formamlde. Ethylene carbonate. 6 Armjd O, a mixture of stearoylamide 6%, oleylnmide 91%, linoylamlde 3.0%. 5 Water.

1 Alkylphenoxypolyethyleneoxyethanol (Igepal DM 5230) Ethylene glycol ethyl ether.

Another apparatus suitable for use in accordance with the present invention is described in US. Pat. 3,408,748.

Another embodiment of an apparatus for carrying out the present invention, as illustrated in FIG. 1, a structure is provided having three distinct chambers, each associated with the others for passage of a base material, e.g., floor covering, from the ambient environment into and out of each chamber and return to the ambient environment. The description of the embodiment of the apparatus of FIG. 1 will have specific reference to its use to dye floor covering; however, it is to be understood that change in size and line speeds may be made to enable the dyeing of lighter weight fabrics.

FIG. 1 has been divided into four sections, the first section 10 being the dye applicator which is not a part of the present invention or apparatus since existing commercial dye applicators can be employed. The second section .11 is the dye diffusion and fixation chamber. The third section 12 is the rinse chamber and the fourth section 13 depicts the final drying section.

Dye diifusion and fixation section 11 The dye diffusion and fixation section 11 comprises a chamber .14 having side walls 15 and 16, a bottom 17 and a top 18. The bottom :17 has, as illustrated, a well 19 which is provided with heating means 20. The heating means may be electrical, steam, or flame systems, commercially available and operative under the conditions here employed, e.g., nature of solvent to be heated, etc.

Along the side wall 15 is an opening 21 which is located near the upper extent of the side wall 15. This opening 21 provides ingress into the interior of the chamber 14 of a base material 22, e.g., floor covering to which a dye formulation has been applied. Located within the chamber 14 extending peripherally around the interior walls at a point just below the opening 21 in side wall 15 is a series of coils 23 which serve as condensing surfaces (for vapors which are generated within chamber 14. These coils 23 establish the upper extent of the vapor zone 27 within chamber 14.

Located directly below said coils 23 is a trough 24 to collect the condensate from coils 23. The trough 24 is in (fluid communication with a storage tank not shown and/ or the well 19 supplying liquid vaporizable solvent to the well 19 as well as solvent for preparation of dye formulations.

The interior of the chamber 14 is provided with idler rolls 25 located in a manner to direct the base material 22 into chamber 14 in a path 26 to maintain the base material 22 within the zone of vapors 27 established 8 Ethofat C 15, coco acids esters of polyoxyethylene glycol.

between the condensing coils 23 and the bottom 17 of the chamber 14. Positioned along the path 26 of the base material 21 through zone 27 of chamber 14 are a series of superheatcrs 2 8. These superheaters 2-8 are illustrated as steam heated finned radiators, although other means such as electrical heaters, gas fired radiators and microwave generators as well as provisions for introducing superheated vapors as shown in FIG. 2 are suitable in their stead.

The location of the condensing coils 23 is such that above the vapor level 27a established thereby is a substantially vapor-free zone 29 which is essentially quiescent in nature. This zone 29 extends across and above each of the other units 12 and 13.

A series of idler rolls 30 are located within unit 12 to direct material 21 into chamber '31 which is the scour unit 12. Located within rinse unit 12, chamber 31 are a series of nozzles 32 which are connected to a pressurized source of rinse liquid. The lower portion of chamber 31 is designed to hold a quantity of scouring liquid 33 suflicient to engulf the base material 21 during its passage through chamber 31. The nozzles are positioned in a manner such that their force is directed against the normal flow of liquid down the base material thus offsetting to some extent the cii'ect of cascading created by liquid flowing downwardly over the heavy nap of the floor covering causing the nap to bend with the flow. The chamber 31 has been provided with a series of condensing coils 34 to condense vapors which might be generated within chamber 33 and a trough 35 to collect the condensed vapor thus preventing vapors from escaping into zone 29. 1 7

Unit 13 is similar in construction to unit 11 but is somewhat of a mirror image thereof. Unit 11 provides a means for removing scouring solvent from the base material and recovering the so-remo'ved solvent.

oftentimes it will not be economical or desirable to employ radiators 28 such as shown in FIG. 1. When such is not desired, it will be expedient to employ zones defined by plates traversing the path 26 of the fabric as illustrated in FIG. 2 at 22-8. When such is employed, the well 19 and its associated heating coils 20 may be dispensed with. When employing the plates 228, it is of course necessary to provide a solvent vaporizer 236 and a solvent vapor superheater 237.

Further, even the plates 228 illustrated in FIG. 2 are not always essential. As shown in FIG. 3, a vaporizer 336 and superheater 337 are supplied with liquid and vapors and open directly to the interior of chamber 14.

Other modifications will become apparent to those skilled in the art.

The operation of the apparatus illustrated in the figures is self-evident and is readily seen to permit conducting the novel method of dyeing hereinbefore described. The dyeing process of the present invention has been carried out employing a prototype of the apparatus described in FIG. 1 on a laboratory scale with good results.

In the operation of the apparatus described hereinabove, the loss of solvent was about five (5%) percent of that introduced into the apparatus either in the dye formation or as vapor and/or scouring liquor.

It is to be understood that when scouring is not necessary to remove dye assistants, etc., the rinse section 12 and the drying unit :13 need not be employed. Thus one can dye a fabric satisfactorily in an apparatus such as illustrated in FIG. 3.

Another embodiment of an apparatus for carrying out the present invention, as illustrated in FIG. 4, comprises a structure having three distinct chambers, each associated with the others for passage of a base material, e.g., floor covering, from the ambient environment into and out of each chamber and return to the ambient environment. The description of the embodiment of the apparatus of FIG. 4 will have specific reference to its use to dye floor covering; however, it is to be understood that change in size and line speeds may be made to enable the dyeing of lighter weight fabrics.

FIG. 4 has been divided into four sections, the first section 410 being the dye applicator which is not a part of the present invention or apparatus since existing commercial dye applicators can be employed. The second section 411 is the dye diffusion and fixation chamber. The third section 412 is the rinse chamber and the fourth section 413 depicts the final drying section.

Dye difiusion and fixation section 411 The dye dilfusion and fixation section 411 comprises a chamber 414 having side walls 415 and 416, a bottom 417 and a top 418. The side wall 415 is provided with heating means 428e. The heating means may be electrical, steam, or flame systems, commercially available and operative under the conditions here employed, e.g., nature of solvent to be heated, etc. Along the side wall 415 is an opening 421 which is located near the upper extent of the side wall 415. This opening 421 provides ingress into the interior of the chamber 414 of a base material 422, e.'g., floor covering to which a dye formulation has been applied. Located within the chamber 414 extending peripherally around the interior walls at a point just below the opening 421 in side wall 415 is a series of coils 423 which serve as condensing surfaces for vapors which are generated within chamber 414. These coils 423 establish the upper extent of the vapor zone 427 within chamber 414.

Located directly below said coils 423 is a trough 424 to collect the condensate from coils 423. The trough 424 is in fluid communication with a storage tank not shown and/or the well 419 supplying liquid vaporizable solvent to the well 419 as well as solvent for preparation of dye formulations.

The interior of the chamber 414 is provided with idler rolls 425 located in a manner to direct the base material 422 into chamber 414 in a path 426 to maintain the base material 422 within the zone of vapors 427 established between the condensing coils 423 and the bottom 417 of the chamber 414. Positioned along the path 426 of the base material 421 through zone 427 of chamber 414 are a series of nozzles 428. These nozzles 428 are supplied with superheated vapors of a solvent through header 428a which is connected to the exterior piping 428b, a superheater section 428e, a pipe 428d, a fan or blower 428e and a pipe 428 which is connected through the side wall 415 of section 411.

The location of the condensing coils 423 is such that above the vapor level 427a established thereby is a sub- ,stantially vapor-free zone 429 which is essentially quies- 10 cent in nature. This zone 429 extends across and above each of the other units 412 and 413.

A series of idler rolls 430 are located within unit 412 to direct material 421 into chamber 431 which is the scouring unit 421. Located within scouring unit 412 chamber 431 are a series of nozzles 432 which are connected to a pressurized source of rinse liquid. The lower portion of chamber 431 is resignated to hold a quantity of scour liquid 433 sufficient to engulf the base material 421 during its passage through chamber 431. The nozzles are positioned in a manner such that their force is directed against the normal flow of liquid down the base material thus offsetting to some extent the efiect of cascading created by liquid flowing downwardly over the heavy nap of the floor covering causing the nap to bend with the flow. The chamber 431 has been provided with a series of condensing coils 434 to condense vapors which might be generated within chamber 433 and a trough 435 to collect the condensed vapor thus preventing vapors from escaping into zone 429.

Unit 413 is similar in construction to unit 411 but is somewhat of a mirror image thereof. Unit 411 provides a means for removing scouring solvent from the base material and recovering the so-removed solvent.

Other modifications will become apparent to those skilled in the art.

The operation of the apparatus illustrated in the figures is self-evident and is readily seen to permit conducting the novel method of dyeing hereinbefore described. The dyeing process of the present invention has been carried out employing a prototype of the apparatus described in FIG. 4 on a pilot plant scale with good results.

In the operation of the apparatus described hereinabove, the loss of solvent was about five (5%) percent of that introduced into the apparatus either in the dye formulation or as vapor and/or scouring liquor.

It is to be understood that when rinsing is not necessary to remove dye assists, etc., the scouring section 412 and the drying unit 413 need not be employed. Thus one can dye a fabric satisfactorily in an apparatus such as illustrated in FIG. 3.

We claim:

1. An improved method for dyeing natural and synthetic textile materials which comprises:

(a) contacting said textile material with a dyestuff dissolved or dispersed in at least one organic solvent which is a vehicle for said dyestufi;

(b) passing said dyestutf wet textile material through a zone of vapors of a volatile organic solvent, having a boiling point between about 40 C. and the softening point of the textile material, which may be the same or different from said vehicle, said zone being at a temperature suflicient to fix the dyestuff; and,

(c) withdrawing from said vapor zone said textile material with said dye fixed therein.

2. The method of claim 1 wherein the textile material is passed through step (b) in from about 10 to seconds.

3. The method of claim 2 wherein subsequent to withdrawal of the dyed textile material from the vapors of step (c) the textile material is scoured with a liquid organic solvent having a boiling point between about 40 C. and the softening point of the textile material, then passed through a zone of the vapors of said solvent for a time sufiicient to raise the temperature of the textile to at least the boiling point of the solvent to remove the solvent, and finally passing the textile material to an atmosphere substantially free of solvent.

4. The method of claim 3 wherein the solvent removed from the textile materials is recovered by condensing the vapors which form in the vapor zone in excess of those vapors necessary to maintain the zone.

5. The method of claim 1 wherein the organic solvent which is a vehicle for the dyestuif and the vapors within the vapor zone are the same.

6. The method of claim wherein the organic solvent is a halogenated organic solvent.

7. The method of claim 5 wherein subsequent to withdrawal of the dyed textile material from the vapor zone of step (c) the textile material is scoured with a liquid organic solvent having a boiling point between about 40 C. and the softening point of the textile material, then passed through a zone of the vapors of said solvent for a time sufficient to raise the temperature of the textile to at least the boiling point of the solvent to remove the solvent, and finally passing the textile material to an atmosphere substantially free of solvent.

8. The method of claim 1 wherein at least a part of the organic solvent which is a vehicle for the dyestufi is different from and boils higher than the solvent from which the vapors in the vapor zone are generated.

9. The method of claim 8 wherein subsequent to withdrawal of the dyed textile material from the vapors of step (c) the textile material is scoured with a liquid organic solvent having a boiling point between about 40 C. and the softening point of the textile material, then passed through a zone of the vapors of said solvent for a time suflicient to raise the temperature of the textile to at least the boiling point of the solvent to remove the solvent, and finally passing the textile material to an atmosphere substantially free of solvent.

10. The method of claim 9 wherein the textile material is maintained in the solvent vapors of step (b) for from 10 to 180 seconds.

11. An improved method for dyeing textile materials which comprises:

(a) contacting said textile material with a dyestufif for said textile material, said dyestuff being dissolved or dispersed in at least one organic vehicle for said dyestufi, said organic vehicle being selected from at least one of the classes (1) solvents boiling between about 40 C. and the decomposition temperature of the dyestuft" or textile material whichever is lower,

(2) solvents boiling above the decomposition point of the dyestuff and/or the textile material,

thereby to wet the textile material with said dyestutf and said solvent,

' (b) passing said so-wetted textile material through a zone of vapors of an organic solvent of the class (a) (1), said zone being maintained at a temperature sufficient to fix the dyestuif and said zone being maintained at a temperature substantially above that at which the textile material is contacted in step (a);

(c) subsequently introducing the textile material through a liquid bath of solvents of class (a)(1) thereby to remove unfixed dyestuif and any solvent having a boiling point above that of the solvent of (b), if any, as well as any other solvent-soluble materials which are employed along with the dye- Stuff;

(d) passing said so-rinsed textile material through a zone of vapors of a solvent of class (a) (1) which are at a temperature that the textile material is substantially free of all solvents; and

(e) removing the textile material to an atmosphere substantially free of solvent and in a dyed state.

12. The method of claim 11 wherein at least a part of the vehicle of step (a) and the solvent of the vapor zone of step (b) and the solvent of step (c) each is a halogenated hydrocarbon solvent having from 1 to 4 carbon atoms and from 2 to 4 halogen atoms having an atomic number from 9 to 35, and said vapors in the zone of steps (b) and (d) are superheated vapors.

13. The method of claim 11 wherein said organic vehicle and said vapor zone solvent are the same and are selected from the group of halogenated hydrocarbons having from 1 to 4 carbon atoms and 2 to 4 halogen atoms having atomic numbers 9 to 35.

14. The method of claim 11 wherein said textile material is in the form of fibers formed in a loose stock, yarn, fabric or carpet.

15. The method of claim 13 wherein said halogenated hydrocarbon is perchloroethylene.

16. The method of claim 13 wherein said halogenated hydrocarbon is trichloroethylene.

17. The method of claim 13 wherein said halogenated hydrocarbon is 1,1,l-trichloroethane.

18. The method of claim 13 wherein said halogenated hydrocarbon is methylene chloride.

19. An improved method for dyeing natural and synthetic textile materials comprising contacting the material with a dye dissolved or dispersed in an organic solvent, passing the thus wetted fibers through a zone containing Vapors of an organic solvent which boils between about 40 C. and below the decomposition point of the dye and the fibers, said passage through said zone of vapors being accomplished in between about 10 and about seconds, withdrawing the dyed fibers therefrom, scouring excess dye and non-volatile dye assistants from the fibers and drying the fibers.

References Cited UNITED STATES PATENTS 2,274,751 3/1942 Sowter et al. 894 X 2,828,180 3/1958 Sertorio- 8-62 2,999,002 9/1961 Dayvault et al. 8165 X 3,098,691 7/1963 Pascal 8179 X 3,313,590 4/1967 Delano et al. 8-94 X GEORGE F. LESMES, Primary Examiner T. J. HERBERT, 1a., Assistant Examiner U.S. Cl. X.R. 8-174 I mg o UNITED STATES PATENT OFFICE f CERTIFICATE OF CORRECTION Patent No. 3,667 898 Dated 6 June 1972 Inventofls) Sylvester Bergman and Ross R. Dawson It is certified that-error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 9, line 10, change "-fnation" to mulation. Q

Column 10, line 5, change "421." to --412-.

line 8, change resignated" to ilesig:r1 ed-.

Signed and sealed this 12th day or December 1972.

(SEAL) Attest:

EDWARD M-.FLETCHER,JR. ROBERT GOTISCHALK Attesting Officer Commissioner of Patents

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