US3640881A - Procedure for dry cleaning - Google Patents

Abstract

DRY CLEANING COMPOSITIONS CONTAINING HYDROPHILIC OPTICAL BRIGHTENER AND DETERGENT MATERIAL COMPATIBLE THEREWITH CAN BE USED IN CONVENTIONAL COIN-OPERATED, PROFESSIONAL AND, PREFERABLY, INDUSTRIAL DRY CLEANING SYSTEMS TO SIMULTANEOUSLY CLEAN AND BRIGHTEN TEXTILE STRUCTURES AND PARTICULARLY WHITE GARMENTS CONTAINING A SIGNIFICANT MANMADE FIBER CONTENT.

Description

United States Patent 3,640,881 PROCEDURE FOR DRY CLEANING Francis Selim Moussalli, Charlotte, N.C., assignor to Celanese Corporation, New York, N.Y. No Drawing. Filed July 24, 1968, Ser. No. 747,074 Int. Cl. C09d 9/04; (311d 7/52; C23g /02 U.S. Cl. 252171 11 Claims ABSTRACT OF THE DISCLOSURE Dry cleaning compositions containing hydrophilic optical brightener and detergent material compatible therewith can be'used in conventional coin-operated, profes sional and, preferably, industrial dry cleaning systems to simultaneously clean and brighten textile structures and particularly white garments containing a significant manmade fiber content.

BACKGROUND OF THE INVENTION This invention relates to the dry cleaning arts. More particularly, this invention relates to dry cleaning systems containing uniquely compatible cleansing agents and optical brighteners in which textiles, and particularly white fabrics, whether made of natural fibers, man-made fibers or blends thereof, can be quickly, conveniently and repeatedly thoroughly cleansed in conventional dry cleaning equipment with excellent removal of lipophilic and hydrophilic as well as non-soluble soiling materials without causing the material to fade or discolor, yellow, degrade, pill or develop other highly undesirable characteristics.

As used within this specification and the appended claims, dry cleaning refers to numerous and varied cleansing processes normally considered to be encompassed by the term as used by those skilled in the art and, generally, refers to the employment of fluid, and particularly liquid, hydrophobic, organic cleaning solvents in systems in which the textile articles remain dry only in the sense that the solvent does not extensively penetrate individual fiber filaments causing them to become wet or swollen as cotton becomes in aqueous media. Conventional dry cleaning systems in wide use today generally employ either a halogenated hydrocarbon solvent, such as carbon tetrachloride, trichloroethylene rand perchloroethylene, or a petroleum naphtha cut such as Stoddards solvent as the predominant solvent-cleaner.

The dry cleaning solvents of choice are characterized by their non-flammability, short drying times, and excellent dispersion and solvation properties for hydrophobic soiling substances. However, such solvents due to their organic nature are not capable of thoroughly cleaning textile materials exhibiting hydrophilic surfaces or heavily soiled with water-soluble contaminants. Particularly critical problems have developed with attempts to dry clean white or other light, e.g., pastel colored, garment fabrics, and in particular, white fabrics having a man-made fiber content, due to the natural tendency of white textiles to yellow during prolonged exposure to light and the inability of conventional dry cleaning systems to arrest this progressive fading or color change during the dry cleaning process. Additionally, water-soluble stains and soils tend to become permanently embedded or set in fabrics during dry cleaning and subsequent pressing. Thus, in addition to designing a dry cleaning system capable of removing both water and organic solvent-dispersible soils as well as non-soluble particulates from the material, it is a necessary and essential requirement that the dry cleaning procedure retain, and, if required, restore the treated articles to a condition closely approximating the characteristics and appearance of the material when new. The above is especially crucial for white light weight and heavy weight garments containing synthetic fibers, whether intimately blended with natural fibers or not, which are subjected to frequent soiling necessitating cleaning following only one or two wearings, such as shirts, blouses, work pants, uniforms and the like. These fabrics exhibit color, luster, hand, wrinkle resistance, abrasion resistance, dimensional stability and other highly desirable properties which must be maintained throughout numerous cleaning cycles over the normal expected life of the garment. As examples of synthetic or man-made fibers used in wearing apparel and other textiles, there may be mentioned polyesters, acetates, both secondary and triacetate, polyamides, polyolefins and the like, which may be utilized in interwoven fabric constructions comprising percent synthetic or may be present in blends of e.g. 35 to 65 percent cotton or the like.

Therefore, it is an object of the present invention to provide dry cleaning compositions and processes for thoroughly cleaning textiles of all types of soiling substances without deleteriously affecting their highly desirable characteristics such as dimensional stability, abrasion resistance, hand, color and the like. It is still another object of the present invention to provide dry cleaning compositions and processes for cleaning highly soiled white garments, particularly white garments containing fabrics formed from intimate synthetic fiber/natural fiber blends, which in addition to substantially completely removing all soil material from the fabric, restore the fabric to its original white color without adversely affecting other Wanted fabric properties. It is another object of the present invention to provide dry cleaning systems containing uniquely compatible cleansing agents and optical brighteners dispersed throughout conventional dry cleaning solvents particularly suitable for simultaneously cleaning and brightening highly soiled white polyester/cotton wearing apparel without lower abrasion resistance or in any other manner decreasing the normal life span of the garment. Other objects of the invention will appear obvious to those skilled in the art from the detailed description of the invention hereinafter.

THE INVENTION The present invention eliminates the problems existent in conventional dry cleaning processes preventing their employment in the dry cleaning of many types of textile materials such as white fabrics of 100 percent natural and man-made fiber content and man-made fiber/natural fiber blends, by providing a dry cleaning solvent system formulated with a water-dispersible, and preferably water soluble, optical brightener and a compatible detergent material contained within a conventional dry cleaning solvent admixed with a small quantity of water. Additionally, the present invention provides a process for formulating a dry cleaning system comprising a dry cleaning solvent containing an intimate dispersion of water, detergent and optical brightener and a process for using the formulation so prepared for thoroughly cleaning and brightening white fabrics.

It is to be understood that the designations textile, fabric, and the like are used herein throughout the specification and appended claims interchangeably and include within their scope every type of textile structure regardless of precise technical classification as woven, knitted, non-woven, and the like.

In accordance with the present invention, dry cleaning systems for cleaning textiles while maintaining and improving their desirable properties such as luster and finish are provided comprising a conventional dry clean: ing solvent such as perchloroethylene and Stoddards solvent containing an ionic or nonionic cleansing agent, a water dispersible, hydrophilic optical brightening agent physically and chemically compatible with the detergent and a small quantity of finely-dispersed water. In a preferred embodiment of the invention, the cleaning agent is an amphoteric detergent and the optical brightener is a water soluble, anionic, stilbene brightener.

Another aspect of the invention is described to a method for preparing the above-disclosed dry cleaning formulation which comprises injecting and thoroughly admixing an aqueous dispersion, preferably a solution of an optical brightener, optionally containing an amphoteric detergent, in a dry cleaning solvent. In another aspect of the present invention, which may be considered as another preferred embodiment thereof, there is disclosed a sequential multistep process for dry cleaning textile materials, specifically white fabrics containing cotton fibers blended with a synthetic fiber such as a polyester, polyamide, acetate, polyolefin and the like, usable in conventional dry cleaning equipment. This process, which results in clean, bright articles, is described in detail hereinafter.

DETAILED DESCRIPTION OF THE INVENTION This invention is based in part upon the discovery that in conventional organic dry cleaning systems a waterdispersible optical brightener in the presence of a small volume of water can function as a brightness restorer preventing the textile structures being dry cleaned from dullin-g, fading, yellowing or acquiring other undesirable characteristics. In addition, it has been found that the employment of a detergent material, especially those of the amphoteric type, enhances the brightening efiect produced by the optical brightener. The brightener is dispersed, or preferably, dissolved in a predetermined quantity of water which is then added to the dry cleaning solvent by means of conventional dry cleaning injection equipment. To assure uniform dispersion and mixing of the aqueous phase throughout the hydrophobic organic solvent, the water system is injected into the cleaning vessel containing the solvent over a period of two to three minutes prior to or during rotation of the dry cleaning drum.

In the preferred embodiments of the invention, the detergent, which may be a chemical entity or a mixture of two or more compositions exhibiting the necessary polar nature and/ or ionic distribution for classification as a detergent substance, may be admixed with the dry cleannig solvent either prior or subsequent to the injection of the water dispersion of brightener into the dry cleaning solvent. If sufficiently compatible with the optical brightener- Water system due to judicious selection of ingredients, the detergent may be admixed with the brightener prior to injection of the aqueous system into the dry cleaning solvent. Preferably, the detergent is charged to the solvent through an injector and thoroughly dispersed throughout the system prior to the addition of the optical brightener.

The terms water-dispersible optical brightener, nonionic detergen ionic detergent, cationic detergent, anionic detergent and amphoteric detergent as used herein and in the appended claims refer to compositions of matter, whether individual compounds or mixtures of two or more compounds, which possess the desired chemical and physical characteristics which enable them to function respectively as textile optical brighteners orv detergents, as those terms are generally used in the art, in the particular dry cleaning solvent system being used.

Accordingly, the term water-dispersible optical brightener includes within its scope any of a number of known water-dispersible compounds which improve color brightness, and particularly whiteness of textile materials. Optical brighteners exhibit various degrees of solubility in water depending upon the number and type of hydrophobic substituent groups attached to the central organic moiety. In choosing an optical brightener the essential consideration is that the brightener will remain substantially in the water phase under the existing conditions of usage. (Although it may, of course, be preferentially disposed about the water-organic solvent interface.) Therefore, due to the various physical chemical changes possible in commercial and particularly industrial dry cleaning techniques, i.e. temperature, pressure, choice of organic solvent, percentage water and the like, a rigid rule for selection of brightener component need not be stated. As examples of stilbene optical brighteners which should function satisfactorily under most of the environmental conditions found in industrial laundries, there may be mentioned certain of the bis-triazinyl derivatives of 4,4'-diaminostilbene- 2,2'-disulfonic acid prepared from one mole of the reaction product of two moles of cyanuric chloride and one mole of the disodium salt of diaminostilbene disulfonic acid with two moles of aniline. To enhance water solubility of the compound, the two remaining chlorine groups on the triazine rings are replaced by amine groups containing hydrophilic substituents such as N-methylethanolamine and diethanolamine. Other examples of stilbene optical brighteners having a good degree of water solubility are naphthotriazolyl stilbene sulfonic acid and other fully sulfonated, amine substituted cyanuric chloride-disodium diaminostilbene disulfonate reaction products.

Optical brighteners function by absorbing invisible ultraviolet radiation and emitting the same in the visible spectrum, preferably as blue-White light. Thus, the optical brightening agent actually generates white visible light which is seen as part of the total light reflectance of the material containing the brightener. When used with fabrics having a natural tendency to yellow, the additional reflected light, particularly if blue-white, mask any yel low discoloration, decelerates the yellowing process and gives a pronounced whitening effect to the fabric. At the present time, no one has adequately explained in what manner optical brighteners associate with textile materials. It is believed that the factors involved are those probably accounting for dye uptake, namely, a combination of hydrogen bonding, Van der Waals forces and aggregation. While all three factors are probably involved with hydrophilic substrates, the main attractive force with synthetic fibers such as polyester, polyamide, and polyolefin is probably that of Van der Waals forces.

In a like manner, the dry cleaning detergent materials may be selected from many of the vast number of cleaning agents currently available to the dry cleaning industry. As examples of these, there may be mentioned amine sulfonates, such as isopropylamine dodecyl benzene sulfonate, sorbitan fatty acid esters, petroleum sulfonates, phosphate esters such as sodium dodecyl phosphate, ethoxylated alkyl phenols such as ethoxylated nonyl phenol and nonylphenoxy-poly(ethyleneoxy) ethanol succinates such as sodium di(ethyl hexyl) sulfosuccinate and combinations thereof. The most important property which the detergent, whether cationic, anionic, or nonionic, must possess is that of compatibility with the optical br ghtener. For instance, with the employment of an anionic optical brightener, such as a stilbene brightening agent, the detergent material should be either nonionic or anionic to avoid possible chemical inter-action, precipitation, or neutralization of ingredients.

Similarly the term amphoteric detergent encompasses cleansing agents broadly regardless of technical classification as a naturally-occurring detergent, synthetically produced material, saponified material and the like. The critical determination to be made in the selection of this preferred type of cleansing agent is to be certain that it exhibits amphoteric properties, that is, the detergent material has both acid and basic properties, or the capacity to simultaneously react as an acid orbase. A secondary consideration, of course, is that the selected detergent must be compatible with the solvent system containing minute suspended droplets of Water. One class of amphoteric compounds, the ampholytic surface active detergents, are particularly useful in the present invention.

Considering the selection of an amphoteric detergent material in greater detail, a cursory examination of a struc- .5 g tural formula withres'pect to apparent potential reactivity for both acids and bases is oftenlmisleading and inconclusive as to the possible amphoteric properties of the compound in question. A perfunctory determination based upon chemical formulae can be especially misleading in determining the possible amphoteric nature of surface activematerials due to their general complex chemical structure; the-presence of a number of groups within the complex molecule possessing various degrees of basicity and acidity as measured by' proton donation or acceptance, Lewis acid and base determination and the like factors; and thepresence of positively and'negativelycharged groups. A fairly reliable test to determine amphoterism is to measure the acid and base dissociation constants of the compound in question. In general, if the values are small and about the same, the compound is likely to possess true amphoterism.

As examples of amphoteric'detergents, there may be mentioned the alkyl amino-carboxylic acids of the formula RR'NR"COOH wherein R is a high alkyl group of over 8 carbon atoms, R is lower alkyl or substituted lower alkyl and R" is an alkylene radical of up to about 4 carbon atoms. Many of the amino carboxylic amphoteric detergents will contain two or more substituted amino groups such as compounds of the general formula 1 wherein R is long chain alkyl ranging up to 12 or more carbon atoms and R, R and R are selected from H or short chain alkyl. Other examples of amino carboxylic acid amphoteric surface active agents, all of which are well known in the art, are the halogenated reaction products of amino carboxylic acids with the condensation products of 3 to 30 molesethylene oxide with alcohols, including phenols containing about 6 carbon atoms, and the condensation products of naturally-occurring fatty acids such as coconut oil fatty acids with hydroxy amines such as diethanolamine and diis'opropanolamine.

Another large group of amphoteric detergents are sulfonic acids of the general formula wherein R is a long chain alkyl group of over carbon atoms and R and R are low molecular weight alkyl and cycloalkyl groups.

Other amphoteric detergents are the condensation products of glycidyl ethers and di-lower alkyl amino sulfonates.

As additional examples of the above amphoteric compounds, there may be mentioned:

Na-( l-dodecyloxy-2-hydroxypropyl) N-rnethylaminoethanesulfonate, N-dodecyl-N-methyltaurine, N-dodecyl-N-ethyltaurine, 4-octodecyl-4-amino butyric acid, 4-pentodecyl-4-amino butyric acid With the employment of the compositions and process of the present invention, textiles, particularly if containing a synthetic fiber such as polyester, may be repeatedly dry cleaned without concern as to modification of the fabric color, hand, finish, texture, overall appearance and other properties. With the practice of the present invention, polyester-containing garments heavily soiled by water and/or oil dispersible agents can be thoroughly cleansed in an inexpensive manner with conventional coin-operated, professional and industrial dry cleaning equipment without danger of fading and yellowing. Garments and other textile articles of all colors remain at least as bright after cleaning as they were before undergoing the cleaning process. Although the invention is described with reference to one of its preferred embodiments in the dry cleaning of polyester-cotton garments, it

is to -be understood, of course, that the system may be employed with any type of article not deleteriously affected by the dry cleaning process.

Without wishing to be bound by one particular theory or explanation for the unexpected results flowing from the use of the invention, it is believed that the invention is dependent upon the employment in conventional dry cleaning systems of a particular combination of waterdetergent-brightener as disclosed hereinbefore. The water phase containing the hydrophilic optical brightener would normally be expected to be uniformly dispersed in finely suspended droplets throughout the organic dry cleaning solvent phase. However, with the addition of the detergent, and particularly an amphoteric detergent, to the dry cleaning system, it'is hypothesized that the detergent, due to its polar nature, ionic distribution, combination of positive and negative charges and/or other intrinsic factors concentrates near the fabric surfaces dnawing the water droplets containing the brightening agent thereto. Consequently the detergent and optical brightener remain highly concentrated in the immediate vicinity of the soiled fabric surfaces instead of being uniformly dispersed throughout the dry cleaning solvent. For this reason, other water-attnacting material such as inorganic salts should not ordinarily be added to the system. However, various compatible adjunctive agents such as additional cleansing agents, wetting agents, anti-foaming agents, buffering agents, viscosity regulators and the like normally soluble or dispersible in the organic or aqueous phase may be readily used during the cleaning operation.

As disclosed hereinbefore, an important feature of the present invention resides in the discovery that water dispersible optical brighteners can be used aduantageously in hydrophobic dry cleaning systems. To this end, it is critical that a small quantity of water, at times less than 1 volume percent based on the volume of dry cleaning solvent, be present in the cleaning system. 'Usually the quantity of water containing the optical brightener which is injected into the solventwill suifice to form a relatively stable dispersion of water droplets which will supply the necessary amount of water. If for some reason a substantial proportion of the water should be removed from the solvent system during the cleaning cycle, such as from absorption by dry, hydrophilic materials being cleaned, additional water may be injected into the system.

Generally, the ingredients used in the present invention may be employed in a broad range of about 1,000 p.p.m. to 0.01 p.p.m. (w./v.) for the optical brightener, about 5 to 0.04 percent (W./v.) for the detergent and about 7.0 to 0.04 percent (v./v.) for the water, all based upon the dry cleaning solvent, and prefenably the formulation will consist of 10 to 0.1 p.p.m. (w./v.) optical brightener, 2 to 0.3 percent (w./v.) detergent and 4.0 to 0.5 percent water, with the balance being solvent. Most preferably, the dry cleaning system will contain 2 p.p.m. (W./v.) brightening agent, 0.375 percent (w./v.) detergent and 0.75 percent (v.'/v.) water based on the organic solvent.

Of course, the above general percentages of ingredients in the formulation can vary widely depending upon the relative strengths of the particular optical brightener and detergent employed and type of material being treated. For instance, many of the newer entirely synthetic detergent materials are operable at low concentrations while amphoteric detergents prepared from, for example, naturally occurring fatty acids will often be required in higher concentrations approaching percent (w./v.) and above based on the dry cleaning solvent.

At times, particularly when the optical brightener is a stilbene-containing compound and the brightener formulation is to be prepared in bulk quantities for use over a period of 3 or 4 days or longer, the large molecules of the optical brightener may begin to precipitate out of solution and collect at the bottom of the storage vessel as a fine powder. Although redispersion and agitation of brightener in the water prior to usage would appear toredissolve the 7 compound, it may be desired to incorporate an inert, adjunctive solvent in the brightener formulation to assure stable solvation over long periods of time. The particular solvent system employed will not be critical as long as the formulation will provide the necessary quantities of brightener and water when added to the dry cleaning system and the additional solvent remains inert throughout the cleaning process. The solvent system must retain its hydrophili-c character and will usually contain a substan- Although this exampleillustrates one preferred embodiment of the invention it will be obvious to those of ordinary skill'in the art to modify the overall process in various ways such as by manipulating' the' order of process steps; adding conventional dispersion, anti-foam and the like agents to the system; substituting other compatible non-ionic, anionic and cationic detergents for the Emerbrite 75.15 and Emerbrite 3723; and substituting other optical brighteners ,for the one specified in the example.

y 5 percent q y of water- As'examples Additionally, one cleaningcycle may be preferable in of such ad unctive solvents, there may be mentioned celsome instances i g" upon the type and o f losolve, methylceuosolve and methylethylkeiomi' textile being cleaned 'de'gr'ee of soiling present andthe The following examples are Presented lnustrate like, all of which is within the skill of those working in min Preferred F PW of the invent1n and not the art. Usually, the percentage ofwater used in the dry to be consumed as llmltmg P Scope of the mventlol} as cleaning system is sufficient to raise the solvent pressure defined by aPPerfded clalms- All Parts are by Welght in the filter above a reasonably safelevel in conventional unless Otherwlse mdlcatedperchloroethylene industrial dry cleaning systems if the EXAMPLEI solvent containing .the Water is. subjected to filtration. Therefore, in the preferred process the solvent from the (a) first cleaning cycle is'distilled and not filtered. Of course,

This example illustrates one of the preferred embodiwith the use of improvedfiltration equipment, one cleanments of the invention for dry cleaning heavily soiled ining cycle could suflice. dustrial garments by means of a multi-step dry cleaning process applicable for use in conventional industrial dry EXAMPLE cleaning equipment. (a)

Initially, a stable optical brightener solution is prepared Example I is repeated fi '8 the fbllowin'g dry d e ani n by dissolving two parts stilbene optical brightener Tinopal t Y g 4BM/ 154 available from Geigy Chemical Corporation in iggg g m the first cleanmg cycle with equally good 80 parts boiling water, allowing the solution to cool to Y i p v about 80 degrees centigradeand then adding 18 parts Nonylphenoxy-poly(ethyleneoxy) ethanol noneionic de- Cellosolve with agitation to produce a stable solution of 2 tergent0.5 percent (w./v.) percent optical brightener which may be stored in a light Tinopal BHS water soluble optical brightener available impervious container until needed. from Geigy Chemical Corporation- 6 p.p.r n.

Thirty pounds of white work uniforms of 65 percent Water-2 percent (v./v.) polyester/ percent cotton fiber content heavily soiled 35 Perchloroethylene-- gallons with dirt, grease, oil and perspiration are placed in a b conventional rotatable dry cleaning basket of standard construction containing 40 gallons of perchloroethylene. Part (a) of this example is repeated with Tinopal 4 Utilizing conventional injection dry cleaning equipment, 40 BM/154 optical brightener with equally good results.

24 ounces of the 2 percent optical brightener solution and 12 ounces of Emerbrite 7515 amphoteric detergent avail- EXAMPLE HI able from Emery Industries, Inc., are charged to the clean- This example illustrates the superior results and particuing vessel over a period of 2-4 minutes. After 7 minut larly enhanced whiteness achievedthrough-the practice of of cleaning time have elapsed the cleaning system is the presentinventiom.

charged to the still to separate water and distillable Individual shirts of 65/35 polyester/cotton are cleaned organic contaminates from the perchloroethylene and the using the process of Example I modified as indicated begarments are centrifuged to a wet weight of about 60 low in the sample identification with relative whiteness pounds. Following the centrifugation step, 40 gallons determined on a Hunter Reflectometer.

Hunter rating 1 2 3 4 5 6 G(E) green reflectance excluding UV 79.9 75.6 73.5 78.9 81.6 80.5 B(I) blue reflectance including UV '91.7 82.9 81.9 89.8 93.1 90.8 B(E) bluereflectauce excluding UV 77.6 71.3 70.7 776.5, 79.3 78.0 B(I)-B(E) ercent blue reflectance due to optical brightener) 14.1 11.6 11.2 13.3 13.8 12.8

4B (I)3G(E (equation for relative whiteness) perchloroethylene containing 12 ounces of Emerbrite 3723 non-ionic detergent, also available from Emery Industries, Inc., is charged to the cleaning vessel and the garments are treated in a second cleaning cycle for an additional seven minutes with the solvent being continuously filtered for removal of insoluble soils from the system. With the completion of the second cleaning cycle, solvent is discharged and the garments are centrifuged to a weight of about pounds. Residual solvent is evaporated and the clothes are aerated and dried.

The white garments removed from the dry cleaning cylinder have been thoroughly cleaned and are as and bright as comparable new garments.

The dry cleaning process of part (a)'of this example is repeated using N-dodecyl-N-methyltaurine and naphthotriazolyl stilbene sulfonic acid as the respective detergent and opticalbrightening materials with equally good results.

White SAMPLE IDENTIFICATION (1) New control shirt I (2) 1 wearingthen dry cleaned once in first cycle of Example I without brightener (3) 3 wearingsdry cleaned after each wearing in only the second cycle 'of Example I with no added brightener (4) 1 wearing-then dry'cleaned twice (5) '1' wearing-then' dry cleaned once (6) 1 wearing-then dry cleaned once' Samples dry cleaned up to 25 times have not shown suflicient brightener accumulation in the test fabrics to adversely affect other desired garment characteristics.

It is contemplated within the scope of the invention that other compatible agents which affect the brightness of fabrics by operating through other mechanisms and therefore not technically classifiable as optical brighteners may be included in the dry cleaning formulation to enhance, modify or otherwise affect the appearance of the fabric. For instance, it has been found that dyes producing blue and violet tints on fabrics will enhance and at times synergize the effect produced by the optical brightener formulation without added dye. This result is unexpected since it would seem logical that the tint would reduce light reflection, thereby decreasing fabric brightness and causing the fabric to assume a grey appearance. As examples of other compositions which may be employed at various points in the process to augment brightness, there may be mentioned certain film-forming resins and finishes such as polyvinyl pyrrolidone.

As an example, a brightener formulation containing 15 p.p.m. Tinolite Brilliant Violet 41375 and 2 p.p.m. Tinolite Padding Brilliant Blue GL 23, both available from Geigy Chemical Corporation, in addition to the water-dispersible optical brightener produces a whiteness and brightness when used in the dry cleaning process of Example I surpassing that resulting from the use of the optical brightener without dye.

While various preferred embodiments of the present invention have been described, it is to be understood that the scope of the invention is to be limited solely by the appended claims in view of the specification.

What is claimed is:

1. A dry-cleaning composition consisting essentially of from about 0.01 to about 1000 parts per million of a Water soluble, anionic, stilbene optical brightener which is a bis-triazinyl derivative of 4,4'-diaminostilbene-2,2'- disulfonic acid prepared from one mole of the reaction product of two moles of cyanuric chloride and one mole of the disodium salt of diaminostilbene disulfonic acid with two moles of aniline; from about 0.04 to about 5 percent of a detergent selected from the group consisting of anionic, nonionic, and amphoteric detergents; from about 0.04 to about 7 percent of water; and a hydrophobic, organic dry-cleaning solvent.

2. The composition of claim 1, wherein the dry cleaning solvent is selected from the group consisting of halogenated hydrocarbon and petroleum naphtha solvents.

3. The composition of claim 2, wherein said detergent is an amphoteric detergent.

4. The composition of claim 3, wherein said composition is comprised of from about 0.1 to about 10 parts per million of said optical brightener, from about 0.3 to

about 2 percent of said detergent, and from about 0.5 to about 4 percent of water.

5. The composition of claim 4, wherein said dry cleaning solvent is selected from the group consisting of trichloroethylene, perchloroethylene, and Stoddards solvent.

6. The composition of claim 5, wherein said composition is comprised of about 2 parts per million of said optical brightener, about 0.375 percent of said amphoteric detergent, and about 0.75 percent of water.

7. A process for dry-cleaning a textile structure comprising the step of treating said textile structure with a dry cleaning composition consisting essentially of from about 0.01 to about 1000 parts per million of a water soluble, anionic, stilbene optical brightener which is a bis-triazinyl derivative of 4,4-diaminostilbene-2,2-disulfonic acid prepared from one mole of the reaction product of two moles of cyanuric chloride and one mole of the disodium salt of diaminostilbene disulfonic acid with two moles of aniline; from about 0.04 to about 5 percent of a detergent selected from the group consisting of anionic, nonionic, and amphoteric detergents; from about 0.04 to about 7 percent of water; and a hydrophobic, organic dry-cleaning solvent.

8. The process of claim 7, wherein said detergent is an amphoteric detergent.

9. The process of claim 8, wherein said composition is comprised of from about 0.1 to about 10 parts per million of said optical brightener, from about 0.3 to about 2 percent of said detergent, and from about 0.5 to about 4 percent of water.

10. The process of claim 9, wherein said dry cleaning solvent is selected from the group consisting of trichloroethylene, perchloroethylene, and Stoddards solvent.

11. The process of claim 10, wherein said composition is comprised of about 2 parts per million of said optical brightener, about 0.375 percent of said amphoteric detergent, and about 0.75 percent of water.

References Cited UNITED STATES PATENTS 1,948,045 2/1934 Parkhurst 252171 2,643,198 6/1953 Savidge et al. 8142 2,717,824 9/1955 Avery 8-142 3,177,207 4/1965 Siegel et al. 252899 3,335,091 8/1967 Gilbert 252153 3,392,122 7/1968 Obayashi et al. 25289 3,394,173 7/1968 Hausermann 25289 LEON D. ROSDOL, Primary Examiner W. E. SCHULZ, Assistant Examiner US. Cl. X.R.