US3762859A - Enhancing the apparent whiteness of fabrics by applying an effective amount of an alkali and heat stable water soluble disazo blue dyestuff fabric softening and detergent composition therefor - Google Patents

Abstract

The apparent whiteness of fabrics is enhanced by a method of treating the fabrics with an effective amount of an alkali and heat stable water-soluble disazo dyestuff using a sulfonated disazo dyestuff of the diphenyl, dinaphthyl type. A fabric softening and laundry detergent composition are disclosed therefor.

Description

United States Patent Wixon et al.

Oct. 2, 1973 ENHANCING THE APPARENT WHITENESS OF FABRICS BY APPLYING AN EFFECTIVE AMOUNT OF AN ALKALI AND HEAT STABLE WATER-SOLUBLE DISAZO BLUE DYESTUFF, FABRIC SOFTENING AND DETERGENT COMPOSITION THEREFOR Inventors: Harold Eugene Wixon, New

Brunswick; Robert Henry Trimmer,

Edison, both ofNJ.

Assignee: Colgate-Palmolive Company, New

York, N.Y.

Filed: Mar. 15, 1971 Appl, No.: 124,510

US. Cl 8/18, 8/26, 8/41 R, 8/41 B, 8/41 C, 8/41 A, 8/77, 252/875,

Int. Cl...... D06p 5/02, C09b 35/16, D06p 1/02 Field of Search 8/18, 26, 41, 77; 252/875, 545, 110, 117; 260/2075 Primary Examiner-Harold Ansher Assistant Examiner-Patricia C. Ives Attorney-Herbert S. Sylvester, Murray M. Grill, Norman Blumenkopf, Thomas J. Corum, Richard N.

Miller, Robert L. Stone and Kenneth A. Koch [57] ABSTRACT The apparent whiteness of fabrics is enhanced by a method of treating the fabrics with an effective amount of an alkali and heat stable water-soluble disazo dyestuff using a sulfonated disazo dyestuff of the diphenyl, dinaphthyl type. A fabric softening and laundry detergent composition are disclosed therefor.

17 Claims, No Drawings 1 2 ENHANCING THE APPARENT WHITENESS OF The disazo blue dyestuffs of the invention are alkali FABRICS BY APPLYING AN EFFECTIVE AMOUNT and heat stable and water-soluble and are sulfonated OF AN ALKALI AND HEAT STABLE with at least one and preferably two or more alkali WATER-SOLUBLE DISAZO BLUE DYESTUFF, metal sulfonate radicals. The compounds will also pref- FABRIC SOFTENING AND DETERGENT 5 erably contain two naphthyl rings and two phenyl rings.

COMPOSITION THEREFOR Highly desirable disazo dyestuffs are those of the phen- This invention relates to compositions for, and a yl-azo-naphthyl-azo-phenyl type and the phenyl-azomethod of, enhancing the apparent whiteness of fabrics naphthyl-azo-naphthyl type. Such compounds will prefby treating the fabrics with a disazo dyestuff, and more erably have the following structural formulas:

R e. R. R. Ri i e,

50 M SOzIHCH: S OaM a SOQVHCH:

and

.. R2. R3. WET. o o A 63 SOaM l Rs particularly to the use of a sulfonated disazo dyestuff of and include compounds having such formulas them the diphenyl, dinaphthyl type. selves and the metal complexes (for example the coplt has been found that the use of alkali and heat sta- P nickel and a t complexes) of those compounds. 1 ble, water-soluble disazo blue dyes in relatively small the above formulas each f R, 1 a a 4 and R5 amounts makes i ibl to enhance h apparent represents a moiety selected from the group consisting whiteness of fabrics regardless of when it is applied. It of y g halogen, y y lower a o y f 1-3 is possible to use these materials either as an after rinse, Carbon atoms and lower alkyl of Carbon atoms, M in a f b i Softener, in a pre soak, or when used in is an alkali or alkaline earth metal, such as sodium, pobination with a liquid or solid detergent composition. [855mm, calcium magnesium or the like (with sodium The such compounds of the invention are so effective being the Preferred cation) and A is that, when used in combination with other materials 'Y such as in a laundering composition, there need not be A highly desirable specific disazo dyestuff of the pheso much dyestuff used that the composition itself benyl-azo-naphthyl-azo naphthyl type is C.i. Acid Blue comes colored. In fact, many particulate laundry deterl 13 which has the structural formula:

Naoas gents appear to be even whiter with these color materi- A specific dyestuff material of the phenyl-azo-naphtals than when they are omitted. Furthermore, the use hyl-azo-pnenyl type is the bis-copper complex of 0H OH (Int H0 0 -N=N- N=N@ CHJNH'OQIS Niloas @NEH 0 SO3N21 soz-NHcHa of such small quantities of bluing agent can be used that which is formed by the reaction of 2 moles of 2-aminoit becomes economically desirable to incorporate the N-methyl, l-phenol-4-sulfonamide with 1 mole of 6,6- material into ordinary laundry detergent compositions. iminobis-l-naphthol-3-sulfonic acid and converted to The use of the bluing agents heretofore known in the the bis-copper complex by treatment with ammoniacal art has often resulted in an undesirable build-up of blue copper sulfate. This compound is known as C I. Dire t color on the fabrics treated in those instances where Vi let 48 and is ld as Sirius Supra Violet BL by Vethe compositions have been repeatedly applied over a rona Dyestuff. period of time. The resulting residual color is not con- Mix ur s of the blue dyestuffs disclosed herein can sidered desirable. It has been discovered that any residalso be used, an p ia ly desirable mixture being the [33] color that is imparted by the compounds of the inmixture OfC.l. AClCl Blue 1 l3 and Cl. Direct Violet 48 vention can readily be removed simply by bleaching the a Fall) of 91l l0 fabrics with commonly used bleaching compositions. In a preferred embodiment of this invention it is con- The fabrics can then again be treated with a disazo dye templated that the blue disazo dyestuffs disclosed of the invention to provide desirable whitening. herein will be incorporated into a laundering composiphate so as to form a water-soluble detergent.

Examples of suitable anionic detergents which fall within the scope of the anionic detergent class includethe water-soluble salts, e.g., the sodium, ammonium, and alkylolammonium salts, of higher fatty acids or resin salts containing about 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms. Suitable fatty acids can be obtained from oils and waxes of animal or vegetable origin, e.g., tallow, grease, coconut oil, tall oil and inn tures thereof. Particularly useful are the sodium and potassium salts of the fatty acid mixtures derived from coconut oil and tallow, e.g., sodium coconut soap and potassium tallow soap. 7

The anionic class of detergents also includes the water-soluble sulfated and sulfonated synthetic detergents having an alkyl radical of 8 to 26, and preferably about 12 to 22 carbon atoms, in their molecular structure. (The term alkyl includes the. alkyl portion of higher acyl radicals.)

Examples of sulfonated anionic detergents include higher alkyl aromatic sulfonates such as the higher alkyl benzene sulfonates containing from l'to 16 carbon-atoms in the higher alkyl group in a straight or branched chain, e.g., the sodium, potassium and ammonium salts of higher alkyl benzene sulfonates, higher alkyl toluene sulfonates, higher alkyl phenol sulfonates, and higher naphthalene sulfonates. A preferred sulfonate'is linear alkyl benzene sulfonate having a high content of 3 (or higher) phenyl isomers and a correspondingly low content (well below 50 per cent) of 2- (or lower) phenyl isomers, i.e., wherein the benzene ring is preferably attached in large part at the 3 or higher (e.g., 4, S, 6 or 7) position of the alkyl group and the content of isomers in which the benzene ring is attached at the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U.S.

Pat. No. 3,320,174. I m

Other suitable anionic detergents are the olefin sulfo nates, including long-chain alkene sulfonates, longchain hydroxyalkane sulfonates or mixtures of allcenesulfonates and hydroxyalkane-sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of SO with long-chain olefins containing 8 to 25, preferably 12-21, carbon atoms and having the formula RCH=CHR where R is a higher alkylgroup of 6 to 23 carbons and R, is an alkyl group of l to 17 carbons or hydrogen to form a mixture of sultones and alkene-sulfonic acids which is then treated to convert the sultones to sulfonates.

Further examples of sulfate or sulfonate detergents are paraffin sulfonates containing about -20, preferably about -20, carbon atoms, e.g., the primary parafiin sulfonates made by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates havingthe sulfonate groups distributed along the paraffin chain as shown in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,741; 3,372,188 and German Pat. No. 735,096;

sodium and potassium sulfates of higher alcohols containing 8 to 18 carbon atoms such as sodium lauryl sulfate and sodium tallow alcohol sulfate; sodium and potassium salts of a -sulfofatty acid esters containing about 10 to 20 carbon atoms in the acyl group, e.g., methyl 0 -sulfomyristate and methyl or :sulfo-tallowate, ammonium sulfates of monoor diglycerides of higher (C C fatty acids, e.g., stearic monoglyceride monosulfate; sodium and alkylolammonium salts of alkyl polyethenoxy ether sulfates produced by condensing l to 5 moles of ethylene oxide with one mole of higher (C -C alcohol; sodium higher alkyl (C -C glyceryl ether sulfonates; and sodium or potassium alkyl phenol polyethenoxy ether sulfates with about 1 to 6 oxyethylene groups per molecule and in which the alkyl radicals contain about 8 to about l2 carbon atoms.

Paraffin sulfonates useful in the present invention are usually mixed secondary alkyl sulfonates having from 10 to 20 carbon atoms per molecule, preferably they willhave at least percent, usually at least percent, of from lO-17 carbon atoms per molecule. Where the major proportion has 14-15 carbon atoms per molecule, optimum foaming performance appears to be obtained at varying concentrations and water hardnesses. These sulfonates are preferably prepared by subjecting a cut of paraffin, corresponding to the chain lengths specified above, to the action of sulfur dioxide and oxygen in accordance with the well known sulfoxidation process. The product of this reaction is a secondary sulfonic acid which is then neutralized with a suitable base to provide thewater soluble secondary alkyl sulfonate for use in the present invention. Similar useful secondary alkyl sulfonate may be obtained by other methods, e.g., by the sulfochlorination method in which chlorine and sulfur dioxide are reacted with paraffins in the presence of actinic light, the resulting sulforyl chlorides being hydrolyzed and neutralized to form the secondary alkyl sulfonates. These compounds are particularly useful in heavy duty liquid detergent formulations containing the bluing agents of the invention.

The suitable anionic detergents include also the C,,-C, acyl sarcosinates (e.g., sodium lauroyl sarcosinate), sodium and potassium salts of the reaction prod uct of higher fatty acids containing 8 to 18 carbon atoms in the molecule esterified with isethionic acid, and sodium and potassium salts of the C -C acyl N- methyl taurides, e.g., sodium cocoyl methyl taurate and potassium stearoyl methyl taurate. I

Anionic phosphate surfactants in which the anionic solubilizing group attached to the hydrophobic group is an oxyacid of phosphorous are also useful in the de-' tergcnt compositions. Suitable phosphate surfactants are the sodium potassium and ammonium alkyl phosphate esters such as (R-O) PO,M and ROPO M in which R represents an alkylchain containing from about 8 to about 20 carbon atoms or an alkyl phenyl group having 8 to 20 carbon atoms and M represents a soluble cation. The compounds formed by including about one to 40 moles of ethylene oxide in the foregoing esters, e.g., [R-O(Et0)n1,PO,M,' are also satisfactory.

sulfonates, olefin sulfonates, higher alkyl sulfates, higher fatty acid monoglyceride sulfates, and higher acyl sarcosinatcs. Particularly desirable salts of this type include the ammonium, triethanolammonium, sodium and potassium salts of the higher alkyl sulfates and the C C acyl sarcosinates.

The nonionic synthetic organic detergents are generally the condensation product of an organic aliphatic or alkyl aromatic hydrophobic compound and hydrophilic alkylene oxide groups. Practically any hydrophobic compound having a carboxy, hydroxy, amido, or amino group with a free hydrogen attached to the nitrogen can be condensed with an alkylene oxide such as ethylene oxide or with the polyhydration products thereof, e.g., polyethylene glycol, to form a nonionic detergent. Further, the length of the polyalkyleneoxy chain can be adjusted to achieve the desired balance between the hydrophobic and hydrophilic elements.

Useful for the nonionic compound types of hydrophobes are higher aliphatic alcohols and alkyl phenols, although others may be used such as carboxylic acids, carboxamides, mercaptans, sulphonamides, etc. The ethylene oxide condensates with higher-alkyl phenols represent a preferred class of nonionic compounds. Usually the hydrophobic moiety should contain at least about 6 carbon atoms, and preferably at least about 8 carbon atoms, and may contain as many as about 50 carbon atoms or more. The amount of alkylene oxide will vary considerably depending upon the hydrophobe, but as a general guide and rule, at least about 5 moles of alkylene oxide per mole of hydrophobe should be used. The upper limit of alkylene oxide will vary, also, but no particular criticality can be ascribed thereto. As much as 200 or more moles of alkylene oxide per mole of hydrophobe may be employed. While ethylene oxide is the preferred and predominating oxyalkylating reagent, other lower alkylene oxides such as propylene oxide, butylene oxide, and the like may also be used or substituted in part for the ethylene oxide.

Other nonionic compounds which are suitable are the polyoxyalkylene esters of the organic acids such as the higher fatty acids, the rosin acids, tall oil acids, acids from petroleum oxidation products, etc. These esters will usually contain from about 10 to about 22 carbon atoms in the acid moiety and from about 12 to about 30 moles of ethylene oxide or its equivalent.

Still other nonionic surfactants are the alkylene oxide condensates with the higher fatty acid amides. The fatty acid group will generally contain from about 8 to about 22 carbon atoms and this will be condensed with about 10 to about 50 moles of ethylene oxide. The corresponding carboxamides and sulphonamides may also be used as substantial equivalents.

Still another class of nonionic products are the oxyalkylated higher aliphatic alcohols. The fatty alcohols should contain at least 6 carbon atoms, and preferably at least about 8 carbon atoms. The most preferred alcohols are lauryl, myristyl, cetyl, stearyl and oleyl alcohols and the said alcohols should be condensed with at least about 6 moles of ethylene oxide and, preferably, about 10 to 30 moles of ethylene oxide. A typical nonionic product is oleyl alcohol condensed with 15 moles of ethylene oxide. The corresponding alkyl mercaptans when condensed with ethylene oxide are also admirably suitable in the compositions of the present invention.

Still other suitable nonionics are the polyoxyethylene polyoxypropylene adducts of l-butanol. The hydrophobe of these nonionics has a minimum molecular weight of 1,000 and consists of an aliphatic monohydric alcohol containing from 1 to 8 carbon atoms to which is attached a heteric chain of oxyethylene and oxypropylene. The weight ratio of oxypropylene to oxyethylene covers the range of 95:5 to 85:15. Attached to this is the hydrophilic polyoxyethylene chain which is from 44.4 to 54.6 per cent of the total molecular weight of 1,400 to 4,000.

A particularly useful group of nonionics is marketed under the trade name Pluronics. The compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The molecular weight of the hydrophobic portion of the molecule is of the order of 950 to 4,000 preferably 1,200 to 2,500. The addition of polyoxyethylene radicals to the hydrophobic portion tends to increase the solubility of the molecule as a whole. The molecular weight of the block copolymers varies from 1,100 to 15,000 and the polyethylene oxide content may comprise 20 to per cent by weight.

Suitable nonionics may be derived by the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. The molecular weight varies from 500 to 4,500.

Other nonionic detergents include the ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof with higher fatty acids containing about 10 to 20 carbon atoms, e.g., sorbitan monolaurate, sorbitan mono-oleate, and mannitan monopalmitate.

The amphoteric detergents which can be used in the compositions of this invention are generally watersoluble salts of derivatives of aliphatic amines which contain at least one cationic group, e.g., nonquaternary nitrogen, quaternary ammonium, or quaternary phosphonium group, at least one alkyl group of about 8 to 18 carbon atoms and an anionic watersolubilizing carboxyl, sulfo, sulfato, phosphato or phophono group in their molecular structure. The alkyl group may be straight chain or branched and the specific cationic atom may be part of a heterocyclic ring.

Examples of suitable ampholytic detergents include the alkyl beta-aminopropionates, RN(H)C H,COOM; the alkyl betaiminodiproprionates, RN(C H.,COOM) the alkyl and hydroxy alkyl taurinates, RN(CH )C H SO M; and the long-chain imidazole derivatives having the following formulas:

wherein R is an acyclic group of about 7 to 17 carbon atoms, W is selected from the group of R OH, R COOM, and R OR COOM, Y is selected from the group consisting of 01-1, R OSO R is an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms, R is selected from the group consisting of alkyl, alkyl aryl and fatty acyl glyceride groups having 6 to 18 carbon atoms in the alkyl or an acyl group; and M is a water-soluble cation, e.g., sodium potassium, ammonium or alkylolammonium.

Formula 1 detergents are disclosed in Volume 11 of Surface Active Agents and Detergents" and in French Pat. No. 1,412,921 and Formula 11 detergents are de- Zwitterionic detergents such as the betaines and sulfobetaines having the following formula are also useful:

wherein R is an alkyl group containing about 10 to 18 carbon atoms, R and R are each C,-C alkyl, R, is an alkylene or hydroxyalkylene group containing about 1 to 4 carbon atoms, and X is C or 8:0. The alkyl group can contain one or more intermediate linkages such as amido, either or polyether linkages or non-functional substituents such as hydroxyl or halogen which do not substantially affect the hydrophobic character of the group. When X is C, the detergent is called a betaine; and when X is S10, the detergent is called a sulfobetaine or sultaine. Preferred betaine and sulfobetaine detergents are l-(lauryl dimethylammonio) acetate, l-(myristyl dimethylammonio) propane-3- sulfonate, and l-(myristyl dimethylammonio)-2- hydroxy-propane-3-sulfonate.

The polar nonionic detergents are those in which the hydrophilic group contains a semi-polar bond directly between two atoms, for example, N O; P As 0; and S 0. There is charge separation between the two directly bonded atoms, but the detergent molecule bears no net charge and does not dissociate into ions.

The polar nonionic detergents of this invention include open-chain aliphatic amine oxides of the general formula R,R,R -,N 0. For the purpose of this invention R, is an alkyl, alkenyl, or monohydroxy'alkyl radical having about l0 to 20 carbon atoms. R and R are each selected from the group consisting of methyl, ethyl, propyl, ethanol, and propanol radicals.

Other operable polar nonionic detergents are the open-chain aliphatic phosphine oxides having the general formula R,R,R;,P 0 wherein R, is an alkyl, alkenyl, or monohydroxyalkyl radical ranging in chain length from 10 to 18 carbon atoms, and R and R are each alkyl and monohydroxyalkyl radicals containing from 1 to 3 carbon atoms.

Cationic surface active agents may also be employed. Such agents are those surface active detergent compounds which contain an organic hydrophobic group and a cationic solubilizing group. Typical cationic solubilizing groups are amine and quaternary groups.

Examples of suitable synthetic cationic detergents are normal primary amines RNH, wherein R is C,,-C,,,; the diamines such as those of the type RNHC, l-l,l-ll-l wherein R is an alkyl group of about 12 to 22 carbon atoms, such as N-Z-arninoethyl stearyl amine and N-2- aminoethyl myristyl amine; amide-linked amines such as those of the type R,CONHC,H,NH wherein R, is an alkyl group of about 8 to 20 carbon atoms, such as N-2- amino ethyl-stearyl amide and N-amino ethylmyristyl amide; quaternary ammonium compounds wherein typically one of the groups linked to the nitrogen atom is an alkyl group of about 8 to 22 carbon atoms and three of the groups linked to the nitrogen atom are alkyl groups which contain 1 to 3 carbon atoms, including alkyl groups bearing inert substituents, such as phenyl groups, and there is present an anion such as halogen, acetate, methosulfate, etc. The alkyl group may contain intermediate linkages such as amido which do not substantially affect the hydrophobic character of the group, e.g., stearyl amido propyl quaternary ammonium chloride. Typical quaternary ammonium detergents are ethyl-dimethyl-stearyl ammonium chloride, benzyldimethyl-stearyl ammonium chloride, trimethylstearyl ammonium chloride, trimethyl-cetyl ammonium bromide, dimethyl-ethyl-lauryl ammonium chloride, dimethyl-propyl-myristyl ammonium chloride, and the corresponding methosulfates and acetates.

The concentration of water-soluble organic detergent in the detergent compositions of the invention varies with the nature and form of the product, that is, usually from about 5 to per cent by weight of detergent can be used. Preferably 8 to 35 per cent by weight is used in solid products, such as spray-dried powders; soap based products will normally contain 30-95 and preferably 50-90 per cent of soap, and from 5 to 30 per cent, preferably 8 to 20 per cent, by weight of detergent is used in liquid products.

Builder salts useful in the detergent formulations of the invention may be of any type well known in the detergent art generally and may be any suitable watersoluble, organic or inorganic builder salt. Useful builder salts include salts of alkali metal, alkaline earth metal, or heavy metals or combinations thereof. Ammonium or an ethanolammonium salt in a suitable amount may be added also, but generally, the sodium, potassium, or similar salts are preferred.

Preferred inorganic hydratable builder salts are the alkali metal polyphosphate salts which have the property of inhibiting precipitation of calcium and magnesium material in aqueous solution and of contributing to the heavy-duty performance of the detergent product. They may be considered as derived from orthophosphoric acid or the like by the removal of molecularly-bound water, though any suitable means of manufacture may be employed if desired. Such complex or molecularly dehydrated polyphosphate salts may be used in the form of the normal or completely neutralized salt, e.g., pentapotassium tripolyphosphate, pentasodium tripolyphosphate, and potassium acid tripolyphosphate. The alkali metal salts of tetraphosphoric acid may be used also. The alkali metal polyphosphate salts may be used in either anhydrous form or partially hydrated form.

Typical examples of hydratable organic builder salts which may be employed alone or in the aforementioned admixtures include the water-soluble aminopolycarboxylates such as the trisodium salt of nitrilotriacetic acid and the di-, tri-, and tetrasodium salts of ethylene-diamine tetraacetic acid.

Other hydratable alkaline builder salts may be employed also, such as the soluble alkali metal borates, sulfates, carbonates, bicarbonates and silicates. Suitable silicates are sodium silicates having an Na,0 to SiO ratio of 12.35, 12.5, 1:32 and so forth. Other suitable materials include citrates, diglycolates, nitrates chlorides, perborates and percarbonates.

Mixtures of two or more inorganic or organic salts can be used, as can mixtures of inorganic salts with inorganic salts. The proportion of builder salts is preferably, for example, in the range of about I to 20 parts per part of the active detergent.

Various other materials may be added in suitable amounts. Materials such as the higher fatty acids amides may be added to improve detergency and modify the foaming properties in a desirable manner. Examples thereof are the higher fatty acid alkanolamides, preferably having 2-3 carbons in each alkanol group and a fatty acyl radical within the range of l-l8 carbons, preferably I0-l4 carbons, such as lauric or myristic monoethanolamides, diethanolamides and isopropanolamides. Tertiary higher alkyl amine oxides such as having about -18 carbons in one alkyl group, e.g., lauryl or myristyl dimethylamine oxide, may be added also. Fatty alcohols of 10-18 carbons such as lauryl or coconut fatty alcohols, or cetyl alcohol are suitable additives also. A hydrotropic material such as the lower alkyl aryl sulfonates, e.g., sodium tolueneor xylene-sulfonates, also can assist processing. In general, these materials are added in minor amounts, usually from about is to 10 percent, preferably 1 to 6 percent based on the total solids.

The mixtures may also contain optical brightening agents or fluorescent dyes (e.g., in amounts in the range of about l/ to 3 percent); germicidal ingredients such as halogenated carbanilides, e.g., trichlorocarbanilide, halogenated salicylanilide, e.g., tribromosalicylanilide, halogenated bis-phenols, e.g., hexachlorophene; halogenated trifluoromethyldiphenyl urea; the zinc salt of l-hydroxy-2-pyridinethione and the like (e.g., in amounts in the range of about 1/50 to 2 percent).

Soil-suspending agents can also be included. These are generally water-soluble or hydrophilic polymeric substances such as the lower alkyl cellulose ethers, e.g., methyl cellulose and ethyl cellulose, hydroxyalkyl cellulose ethers, e.g., hydroxyethyl cellulose, cellulose ethane sulphonic acid, cellulose glycollic acid, carboxy lower alkyl cellulose compounds, e.g., sodium carboxy methyl cellulose, potassium carboxy methyl cellulose, sodium carboxy ethyl cellulose, sodium carboxy propyl cellulose, and the like, water-soluble or dispersible synthetic polymeric materials which may be homopolymers, copolymers, graft copolymers, terpolymers, interpolymers, and the like and are illustrated by polyvinyl pyrrolidone, polyvinyl alcohol, hydrolyzed polyvinyl acetate, polyacrylic acid, polyacrylamide, maleic anhydride copolymers with alkyl vinyl ethers, e.g., methyl vinyl ether, natural products such as starch, and the like. These agents generally present in an amount, for example, in the range of about [/20 to 6 percent).

Other additives include antioxidants such as 2,6-ditertbutylphenol, or other phenolic antioxidant material (e.g., in amounts in the range of about 0.001 to 0.1 percent); bleaching agents; corrosion inhibitors; sequestrants, e.g., ethylene diamine tetraacetic acid, sodium gluconate, and the like; alcohols to improve the compatibility of the various components such as ethanol, propanol and isopropanol; tarnish inhibitors such as ethylene thiourea; perfumes; and thickening agents.

As stated above, the bluing agents are useful when applied from presoak products as well as from regular laundry detergent compositions. Presoak products are similar to the laundry detergent compositions and generally contain a surface active agent and a builder salt such as those described above. The presoak product also often will contain an enzyme of the proteoiytic type (e.g., pepsin, subtilisin, trypsin, papain, bromelin, and the like). The surface active agent is typically present in an amount of 3-95 percent by weight of the presoak composition, preferably about 5-25 percent by weight. Generally the builder salt, when present is employed in the amount of 30-90 percent by weight, and, W6 EEHHEG, the enzyme is present in amounts of 0.001 to 4.0 per cent preferably 0.05 to 2.0 per cent by weight. As in the use of the ordinary laundry detergent various other additives can be included to alter or enhance the effectiveness and the esthetics of the composition.

The bluing agents can also be applied to fabrics when incorporated into a fabric softener composition. Fabric softeners are of any suitable type known to have the de sired conditioning effects. Thus, cationic, amphoteric, nonionic and anionic surface active agents are useful. Included in this group are the quaternary ammonium halides such as the mixed higher and lower alkyl ammonium chlorides and bromides wherein there are present one or two higher alkyls of 8 to 20 carbon atoms, preferably l2 to 18 carbon atoms, and two or three lower alkyls of 1 to 4 carbon atoms, preferably of l or 2 carbon atoms. Instead of a higher alkyl radical an aryl alkyl radical such as benzyl may be used.

Exemplary of useful cationic compounds are distearyl dimethyl ammonium chloride, lauryl trimethyl ammonium bromide and stearyl dimethyl benzyl ammonium chloride. Also useful are various other cationics, such as alkyl pyridine salts, alkyl imidazolines, higher alkyl amines, of the primary, secondary, or tertiary types and higher alkyl guanidine salts, e.g., l-methyl-lstearyl aminoethyl-Z-stearyl imidazolinium methosulfate, Z-heptadecyl-l-methyl-l(2-stearoylamido)ethyl imidazolinium methyl sulfate, stearyl pyridinium ha lides, cetyl isoquinolinium bromide and alkyl morpholinium chlorides. In the aforementioned cases, lower alkyl is of l to 5 carbon atoms, preferably 1 or 2, and higher alkyl is of about 8 to 20 carbon atoms, preferably 12 to 18.

Of the amphoteric materials those sold as Soromines, Deriphats, Miranols, etc., are good conditioners. The Soromines, AL and AT, are complex fatty amido softeners which have been found to be excellent for the intended purpose. Of the nonionics, the preferred products are polyoxyethylene (4) lauryl ether, sold as Brij 30; myristyl dimethyl amine oxide, sold as Textamine Oxide TA; nonylphenoxy polyethoxy ethanol, sold as Igepal CO-880; and polyoxyethylene sorbitan monostearate, sold as Tween 61.

Among the anionic softeners the ones that are most useful are the water-soluble higher fatty acid soaps and the synthetic organic surface active agents of the sulfuric reaction type. The soaps include the alkali metal, amine, ammonium, and alkanolamine soaps. The higher fatty acids are of 8 to 20 carbon atoms, preferably mostly of 12 to 18 carbon atoms and are those that occur naturally in vegetable and animal oils and fats, usually in mixtures in triglycerides. The amines and alkanolamines are of lower alkyls and alkanols such as those of I to 4 carbon atoms, preferably of 2 to 3 carbon atoms. The sulfuric reaction products are balanced compounds having lipophilic and hydrophilic groups, with the lipophile portion usually being a higher alkyl or alkyl aryl, e.g., alkyl phenyl wherein the alkyl is of 12 to 15 carbon atoms. The higher alkyls may be of 8 to 20 carbon atoms, preferably of 12 to 18. Alternatively, the lipophile portion may be made of polymerization of lower alkylene oxide(s) to a suitable chain length, usually of 10 to 40 oxyalkylene groups of 2 to 4 carbon atoms each. The lipophile balancing group, the hydrophilic moiety, will usually be a water-soluble sulfate or sulfonate of an alkali metal, an alkaline earth metal, ammonium, amine or alkanolamine of the type previously described in conjunction with the nonionic softener exposition.

Lengthy descriptions of the softeners are not given herein because all such compounds are generally applicable to the present invention and are known to those of skill in the art. For example, descriptions of softeners can be found in the reference work Detergents and Emulsifiers 1969 Annual, by John W. McCutcheon, wherein those surface active agents that are especially useful as softeners are so characterized. Also, see the text SYNTHETIC DETERGENTS, by Schwartz, Perry and Berch, published in 1958 by lnterscience Publishers.

Fabric softener compositions may also contain various adjuvants to impart desirable properties in addition to softening and bluing to the fabrics treated. Thus, they may contain bactericides, fungicides, fluorescent or optical brighteners, e.g., aminostilbenes, triazines, ozazoles, pyrazolines, etc., perfumes, deodorants and lubricants.

Still another method for applying the bluing agents of this invention to fabrics simply involves the addition of a premeasured amount of bluing agent in an aqueous medium to a given quantity of fabric to be blued. Regardless of the method used, the disazo dye will nor mally be used in an amount by weight of the disazo blue dyestyff of not greater than 1.5 parts per million parts by weight of the fabric to be treated, and preferably will be less than 1.0 part per million. The lower limit on the amount of disazo blue dye to be added is that amount necessary to effectively whiten the fabrics. Generally at least about 0.03 part per million will be used, and preferably at least about 0.1 part per million is used. When incorporating the dyestuff into a conventional type solid particulate laundering composition in which approximately 100 grams of detergent will be employed for a single load, an amount of dyestuff not more than 0.005 percent by weight, based upon the weight of the detergent composition, will be employed, and desirably not more than 0.003 percent will be employed. Even smaller amounts are generally adequate. For example, when using the preferred C.l. Direct Violet 48 (C.l. 29125) the amount used will normally not exceed that amount necessary to equal 0.5 part per million parts of fabric (0.0015 percent of a conventional granular laundry detergent), and preferably only from 0.1 to 0.4 part per million is used. Accordingly, it will be seen that for a normal wash load it will only be necessary to utilize amounts of blue dye on the order of about U 1000 of a gram. In formulating detergent compositions containing the disazo blue dyestuffs of the invention they may be added in the crutcher before spray drying of a spraydried particulate detergent, or they may be mixed into the composition after spray drying or added at any other time during the formulation of the liquid detergents. They may also be post-added to the detergent composition either alone or on a suitable carrier. The compounds of the invention are both alkali and heat stable and therefore lend themselves to widely varied formulating techniques.

When used in a liquid detergent, a presoak, or a fabric softener composition the per cent of disazo dye used will be approximately twice the amount described above for use in a granular or spray-dried composition. This is because an amount by weight of roughly half of these compositions is used for a normal load of wash compared to the amount of granular detergent used. Thus, for example, a fabric softener composition may contain the disazo blue dye in an amount up to about 0.01% by weight.

The following examples are given to further illustrate the invention. In the examples as throughout the specification all parts or percentages given are by weight unless otherwise specified.

EXAMPLE 1 A spray-dried laundry detergent having the following composition was prepared:

Amount (Wtfk) Llnear tridecyl benzene sulfonate 16.0 Neodol4S-11' 2.0 Sodium tripolyphosphate 35.0 Sodium Silicate (122.35 Na,O:SiO,) 7.0 (Carboxymethyl cellulose 0.5 Optical brighteners 1.0 Polyvinyl alcohol 0.2 Sirius Supra Violet BL 0.0005 Water 10.0 Sodium sulfate 28.0495 Perfume 0.25

a nonionic surface active agent which is a polyethoxylated long chain alkanol, specifically the reaction product of l 1 mols of ethylene oxide with one mol of a blend of 14 and 15 carbon atoms primary alltanols described hereinabove The spray-dried product had a white color, a cup weight of about grams and a density of about 0.35.

A plurality of swatches of cotton, Dacron, Arnel, Orlon, Creslan, nylon and blends of these fabrics together with cleaned cotton towels to form a full load (8 pounds) is washed in an automatic washing machine in ordinary tap water (New Brunswick, New Jersey hardness of about PPM), containing approximately 100 grams of the spray-dried detergent composition equivalent to approximately 0.15 percent of detergent. The wash water temperature is F. and has a pH of approximately 9.5. The washing is continued for 10 minutes after which the load is thoroughly rinsed in the same tap water at a temperature about 90l00 F.

The resulting cleaned and whitened fabrics were evaluated against a similarly constituted batch of fabrics washed with a detergent composition that was the same except that it did not contain the Sirius Supra Violet BL. The evaluation was made by ten panelists under both incandescent light and north daylight. The panelists showed a strong preference for the fabrics that were washed in the composition containing Sirius Supra Violet BL.

The detergent composition itself was considerably whiter looking than a control without the bluing agent. Readings were taken of the detergent and the control on a Hunter D-25 Color Difference Meter and the detergent with the dyestuff was considerably less yellow. The results of the Difference Meter Readings are shown in the chart below wherein Rd is the Reflectance value, -a is the greenness indication, and +b is the yellowness indication.

Rd 0 b Detergent Control 83.2 1 .0 +7.4 Detergnet +Sirius BL dye 78.1 0.1 +4.8

EXAMPLE 2 A spray-dried composition similar to that described above was formulated using 0.002 percent of C.I. Acid Blue 113 instead of the Sirius Supra Violet BL (i.e., C.I. Direct Violet 48).

Again a detergent product was formed which had the ability to enhance the apparent whiteness of the fabrics treated.

EXAMPLE 3 EXAMPLE 4 A spray-dried granular laundry detergent composition can be prepared from the following components:

Amounts (Wt.%) Neodol 45-11 10.0 Sodium Carbonate 45.0 Sodium Silicate (1:2.35. Na,O:SiO,) 18.4 Carboxymethyl cellulose 0.5 Brighteners 0.84 Water 10.0 C.1. Direct Violet 48 0.002 Sodium Sulfate 15.258

The spray-dried product had an 80 gram cup weight and a density of about 0.35.

A load comprising swatches of various fabrics washed in the same way as described above with respect to the fabrics of Example 1 is compared to a control batch. The fabrics treated with the control composition were considerably less white than those treated in accordance with the invention.

EXAMPLE 5 A spray-dried composition similar to that described in Example 4 was formulated using 0.001 percent of C.I. Direct Violet 48 instead of C.I. Acid Blue 113. A substantially white detergent product was obtained. The product clearly enhanced the apparent whiteness of the fabrics treated therewith.

EXAMPLE 6 A composition similar to that described in Examples 4 and 5 above was formulated with the exception that the bluing agent constituted a mixture of 60 percent C.I. Direct Violet 48 and 40 percent C.I. Acid Blue 1 13. The total amount of blue dyestufi' was 0.001 percent.

EXAMPLE 7 A spray-dried laundry composition was formed having the following composition:

Amounts (Wt.%) Linear Tridecyl benzene sulfonate 10.0 Primary C Alcohol with 11 mols ethylene oxide 2.0 Sodium Soap of a mixture of tallow and 2.0 fatty acids Sodium Tripolyphosphate 45.0

9. auto carom To 91 parts of the above formula there was added 9 parts of a 0.0075 percent solution of C.I. Acid Blue 1 13. The blue solution was stirred into the spray-dried powder to form a product of having a cup weight of grams.

A plurality of terry cloth hand towels were washed in grams of the above composition together with 17 gallons of tap water, and control towels were treated with the identical composition without the blue dye. A look-and-see" test clearly showed that the towels treated in the composition with the blue dye are visually whiter than the control towels.

EXAMPLE 8 A product similar to that described in Example 7 above was formulated except that an equivalent amount of C.I. Direct Violet 48 was substituted for the C.I. Acid Blue 113. The resulting product was equally efficacious in enhancing the visual whiteness of test towels.

EXAMPLE 9 A composition similar to that described in Example 7 above was formulated using a detergent having the same composition described therein but wherein the cup weight was grams rather than 80 grams and the amount of C.I. Acid Blue 113 used was sufficient to form a laundry detergent composition containing 0.0013 percent of the dyestuff. A visual examination following a five wash bundle test showed that the composition containing the dye-stuff was again preferred over the control.

When the identical composition was similarly tested with one cup of about five per cent aqueous sodium hypochlorite bleach solution present, the efi'ect of the dyestuff was eliminated and the product as compared to the control was close to parity. The results of the test are shown in the following table.

PANELREFERENCEUM Blue Control No pref. No Bleach 66 23 l 1 With Bleach 41 50 9 EXAMPLE 10 A spray-dried detergent was formulated having the formula:

The above formulation was spray-dried with the C.I. Direct Violet 48 having been added in the crutcher prior to the spray-drying operation. The product powder had enhanced whiteness when visually compared to a control without the bluing agent.

The composition was used to wash test fabrics in a similar manner similar to that described in Example 1 above with the result that panelists judged the fabrics treated with the detergent containing the blue dye to be preferred to a significant degree over a control composition not containing blue dyestuff.

EXAMPLE 11 A laundry soap powder composition was formed having the following composition:

Amount (Wtfk) Sodium Soap of mixed tallow and coconut fatty acids 65.0 Sodium carbonate 1 1.279 Sodium Silicate 10.0 Sodium chloride 2.5 Brighteners 1.07 Perfume 0.15 Water 10.0 C.l. Acid Blue 113 0.001

A load of fabrics of varying composition was washed in 100 grams of the above composition together with 17 gallons of tap water, and control fabric was treated with the identical composition without the blue dye. A visual test showed that the fabrics that were treated in the compositionwith the blue dye were visually whiter than the control fabrics.

EXAMPLE l2 5 A heavy-duty liquid laundry detergent composition was prepared from the following components:

Amounts (Wtfk) Neodol 25-38 (60% A.l.; 14% ethyl alcohol; remainder water) 25.0 Sodium Citrate 20.0 Sodium Xylene Sulfonate (40% A.l.) 10.0 Brighteners 3.3 Perfume 0.25 C.l. Direct Violet 48 0.0025 Water 41.4475

The Neodol 25-38 is an anionic surfactant comprising the reaction product of three mols of ethylene oxide with one mol of a blend of 12 to 15 carbon atoms primary alkanols subsequently sulfated and non-- tralized to form'the sodium salt.

The liquid product had a density of about 1.14 and was designed to be used in an amount of about onethird of a cup in a normal laundry wash load.

A load comprising swatches of mixed natural and synthetic fabrics was washed in the same way as described above with respect to the fabrics of Example 1. When compared to a control batch in which the fabrics were treated with a composition that was the same except for the absence of bluing agent it was found that the batch treated in accordance with the invention appeared to be considerably whiter than those treated by the control.

SOzNHCHJ EXAMPLE 13 A liquid laundry composition similar to that described in Example 12 was formulated using 0.003 percent of C.l. Acid Blue 1 13 instead of C.l. Direct Violet 48. Fabrics treated with the product made in accordance with the invention had enhanced apparent whiteness when compared to a control made without the disazo dye.

EXAMPLE 14 A composition similar to that described in Examples 12 and 13 above was formulated with the exception that the bluing agent constituted a mixture of 50 percent C.l. Direct Violet 48 and 50 percent C.l. Acid Blue 1 13. The total amount of blue dyestuff was 0.0025 percent. Fabrics treated with this composition also had improved apparent whiteness.

EXAMPLE 15 A fabric softener composition was formed having the following composition:

Wtfk Z-Heptadecyl-l-methyl-l [(2-stearoylamido)ethyl] imidazolinium methyl sulfate, A.l. Benzyl Fast Blue 5R (C.l. Acid Blue 113) 1% Solution Aqueous Brightener Solution, 23% A.l. Perfume Water In a 5-wash clean load test, this composition was superior to a control composition in whiteness preference under three lights incandescent, north daylight and fluorescent.

EXAMPLE 16 A laundry pre-soak composition was formuiated from:

Amount (Wt.%) 6.0

Linear tridecyl benzene sulfonate Sodium tripolyphosphate Sodium sulfate Sodium silicate Benzyl Fast Blue 5R (C.l. Acid Blue 113) Brighteners Protease Enzyme (Alcalase, Novo) Moisture S OgNHCH t and those having the formula and the metal complexes thereof, and wherein each of R, R R R R and R is selected from the group consisting of hydrogen, halogen, hydroxyl, lower alkoxy and lower alkyl groups; M is alkali or alkaline earth metal and A is NH, NH-CONH or NHaryl-NH.

2. Method of claim 1 wherein said disazo blue dyestuff is of the diphenyl-dinaphthyl type.

3. A method in accordance with claim 1 wherein said disazo blue dyestuff is present in an amount of from about 0.1 to 0.4 parts by weight per million parts by weight of said fabric.

4. A laundry detergent composition comprising an organic surface active compound selected from the group consisting of a water-soluble alkali metal soap, anionic, nonionic, amphoteric, zwitterionic, polar nonionic and cationic detergents and an effective amount of an alkali and heat stable water-soluble disazo blue dyestuff containing at least one alkali metal sulfonate radical, said composition being adapted to be applied to substantially all commonly used fabrics whereby enhanced apparent whiteness thereof is obtained said dyestuff being selected from the group consisting of compounds having the formula and those having the formula and the metal complexes thereof, and wherein each of R, R R R R and R is selected from the group consisting of hydrogen, halogen, hydroxyl, lower alkoxy and lower alkyl groups; M is alkali or alkaline metal and A is NH, NH'CO'NH or NHarylNH.

S. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff is C]. Direct Violet 48 (CI. 29125).

6. A laundry detergent composition in accordance with claim 5 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.0015 per cent by weight based upon the weight of the total laundry detergent composition.

7. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff is C.l. Acid Blue ll3 (CI. 26360).

8. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff comprises a mixture of C.I. Acid Blue 113 (CI. 26360) and CI. Direct Violet 48 (C.l. 29125).

9. A laundry detergent composition in accordance with claim 4 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.005 per cent by weight based upon the weight of the total laundry detergent composition.

10. A laundry detergent composition in accordance with claim 4 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.003 per cent by weight based upon the weight of the total laundry detergent composition.

11. A laundry detergent composition in accordance with claim 4 wherein said composition is a heavy-duty liquid and said disazo blue dyestuff is present in an amount of up to about 0.01 per centby weight of said composition.

12. A laundry detergent in accordance with claim 4, wherein said surface active compound is selected from the group consisting of linear tridecyl benzene sulfonate, sodium soap of mixed tallow and coconut fatty acids and mixtures thereof.

13. A laundry detergent in accordance with claim 4, further containing water-soluble, organic or inorganic builder salt.

14. A laundry detergent in accordance with claim l3, wherein said builder is an alkali metal polyphosphate.

15. A laundry detergent in accordance with claim 13, wherein said builder is sodium silicate having an Na O to SiO ratio of at least 122.35.

16. A laundry detergent in accordance with claim 4, comprising from an effective amount up to 0.005 percent by weight of disazo dyestuff, from about 5 to 95 percent by weight of organic surface active compound and from about 1 to 20 parts of builder per part of organic surface active compound said dyestuff being selected from the group consisting of compounds having the formula sO S and the metal complexes thereof, and wherein each of R, R,, R,, R R and R is selected from the group consisting of hydrogen, halogen, hydroxyl, lower alkoxy and lower alkyl groups; M is alkali or alkaline earth metal and A is NH, NH-CO'NH or NH-aryl-NH.

17. A fabric softening composition comprising an organic surface active compound and an effective amount up to about 0.0L percent by weight of said composition of an alkali and heat stable water-soluble disazo blue dyestuff containing at least one lakali metal sulfonate radical, said composition being adapted to be applied to all commonly used fabrics whereby enhanced apparent whiteness is obtained and wherein said dyestuff is selected from the group consisting of compounds having the formula R R: R R5 R3 R1 =N A N=N+a $03M SOZNHCHJ SOaM SO2NHCH3 and those having the formula A E V g SOaM and the metal complexes thereof, and wherein each of R, R R R R and R is selected from the group consisting of hydrogen, halogen, hydroxyl, lower alkoxy and lower alkyl groups; M is alkali or alkaline earth metal and A is NH, NH-CO-NH or NH-aryl-NH.

Claims (16)

1. 2. Method of claim 1 wherein said disazo blue dyestuff is of the diphenyl-dinaphthyl type.
2. 3. A method in accordance with claim 1 wherein said disazo blue dyestuff is present in an amount of from about 0.1 to 0.4 parts by weight per million parts by weight of said fabric.
3. 4. A laundry detergent composition comprising an organic surface active compound selected from the group consisting of a water-soluble alkali metal soap, anionic, nonionic, amphoteric, zwitterionic, polar nonionic and cationic detergents and an effective amount of an alkali and heat stable water-soluble disazo blue dyestuff containing at least one alkali metal sulfonate radical, said composition being adapted to be applied to substantially all commonly used fabrics whereby enhanced apparent whiteness thereof is obtained said dyestuff being selected from the group consisting of compounds having the formula
4. 5. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff is C.I. Direct Violet 48 (C.I. 29125).
5. 6. A laundry detergent composition in accordance with claim 5 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.0015 per cent by weight based upon the weight of the total laundry detergent composition.
6. 7. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff is C.I. Acid Blue 113 (C.I. 26360).
7. 8. A laundry detergent composition in accordance with claim 4 wherein said disazo blue dyestuff comprises a mixture of C.I. Acid Blue 113 (C.I. 26360) and C.I. Direct Violet 48 (C.I. 29125).
8. 9. A laundry detergent composition in accordance with claim 4 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.005 per cent by weight based upon the weight of the total laundry detergent composition.
9. 10. A laundry detergent composition in accordance with claim 4 wherein said composition is a granular solid and said disazo dyestuff is present in an amount of up to about 0.003 per cent by weight based upon the weight of the total laundry detergent composition.
10. 11. A laundry detergent composition in accordance with Claim 4 wherein said composition is a heavy-duty liquid and said disazo blue dyestuff is present in an amount of up to about 0.01 per cent by weight of said composition.
11. 12. A laundry detergent in accordance with claim 4, wherein said surface active compound is selected from the group consisting of linear tridecyl benzene sulfonate, sodium soap of mixed tallow and coconut fatty acids and mixtures thereof.
12. 13. A laundry detergent in accordance with claim 4, further containing water-soluble, organic or inorganic builder salt.
13. 14. A laundry detergent in accordance with claim 13, wherein said builder is an alkali metal polyphosphate.
14. 15. A laundry detergent in accordance with claim 13, wherein said builder is sodium silicate having an Na2O to SiO2 ratio of at least 1:2.35.
15. 16. A laundry detergent in accordance with claim 4, comprising from an effective amount up to 0.005 percent by weight of disazo dyestuff, from about 5 to 95 percent by weight of organic surface active compound and from about 1 to 20 parts of builder per part of organic surface active compound said dyestuff being selected from the group consisting of compounds having the formula
16. 17. A fabric softening composition comprising an organic surface active compound and an effective amount up to about 0.01 percent by weight of said composition of an alkali and heat stable water-soluble disazo blue dyestuff containing at least one lakali metal sulfonate radical, said composition being adapted to be applied to all commonly used fabrics whereby enhanced apparent whiteness is obtained and wherein said dyestuff is selected from the group consisting of compounds having the formula