US2624710A - Composition for laundering textiles and for imparting a whitening effect thereon - Google Patents

Description

Patented Jan. 6, 1953 COMPOSITION FOR LAUNDERING TEXTILES.-

AND FOR IMPARTIN'G A.WHITENING EF- FECTI THERE'ON' Richard Thomas, Bromborough', England, assignor to Lever Brothers Company, a. corporation of Maine No Drawing; Application April 10, 1946, Serial No. 661,070. In Great Britain April 12, 1945 6 Claims; 1 This invention relates to washing textiles and compositions adapted therefor. More particularly, it relates to Washing white textile materialswith a detergent composition comprising a substantive fluorescent stilbene derivative which does not darken upon exposure to air, sunlight; or bleaching agents, and to a-detergent composition comprising such a stilbene derivative.

It is well known that. white textile materials with the lapse of time andparticularly after repeated washings tend to lose. their original brightness and white appearance and gradually acquire a yellow tint or similar ofi-white shade. To suppress or counteract this progressive deterioration in color it is customary practice in laundering operationsto. subject the washedmaterial to a blueing treatment. by means.- of. a non-substantive; blueing. agent. such as ultram-arine which en.- hances the apparent: whitenessof' the; materials; It is usual to give the washed. material, after re-= moval ofvthe. detergent liquid, a plurality of rinses in water and the blueing agent isgeneral-ly added to the last rinse.

It has been proposed to eliminate the. yellowish or ofi-white tint of materials such: astextile iabrics, paper and. the like -by, treating. the. materials during manufactureor subsequently by'immer sion or otherwise with a solution of a compound of the. coumarin. group,-. preferably beta-methyl unbelliferone. While, however, beta-methyl umbelliferone and other fluorescent compounds: of the coumarin group are capable of achievinga whitening efiect, this. efiec-t. disappears when the treated fabrics are rinsed, washed, or otherwise treated in aqueoussolutions, due. to th-e non-sub stantive character of the coumarin type of compounds.

It has. been proposed to-treattextile materials, in order to impart colored. fluorescence thereto when illuminated by ultraviolet light, withrelatively large amounts of a stilbene derivative, suchas 4 4 dibenzoyldiaminostilbene-2 2 disulfonic acid, which is applied to the textile in an aqueous bath containing a largev amount of salt, for in.- stance, 20% of Glauber salt. This procedure is obviously notapplicable to laundering processes. Another type ofv stilbene derivative thathas been proposed as a fluorescence, imparting agent is typified by 4:4 -di-p-aminobenzoyldiaminostilbene- 2:2 -disu1ionic acid. This. type of compound is applied tothetextile in an aqueous bathcontaining a large amount of salt, or salt plus an acid. I. have/observed, howeven that. this type of com-- pound. when presenton. textile fibres, is. likely to. undergo; undesirable changes on; contact with air,.

especially in the presence of strong sunlight, and also with oxidising agents, for instance, bleaching agentsof the sodium hypochl-orite type, with the result that the textiles become gradually discolored. Therefore, this-agent is not suitable for imparting lasting whiteness to white textile materials, especially if the treated textile is subsequently subjected to a conventional bleaching treatment. The amount of the stilbene derivative in these particular materials which ar intended to be decorative or clearly visible in ultraviolet light mustbe such as to impart a brilliant colored fluorescence when subjected to ultraviolet light in the absence of light in the visible portion of the spectrum. The color or appearance imparted to. these textiles under ordinary daylight by the stilbene: derivatives is not of any great concern, and. there has been no proposal to use small amounts of stilbenefiuorescent compounds to obtain a whitening effect in ordinar daylight.

It has been proposed to treat textileswith a stilbene derivative containing at least one triazine nucleus in the molecule. in order to impart a whitened appearance to the textile. However, such materials as were obtainable from a commercial supplier showed unsatisfactory stability properties.

It: has: been found, and quite unexpectedly, that the above discussed disadvantages can be sub.- stantially eliminated and an improved whitening efiect of greater stability and durability can be obtained by using as a treating agent a combination of a detergent. and a blue-fluorescent compound which is a derivative of a di-aminobenzoylaminostilbene-sulfonic acid in which at least one of the hydrogen atoms in-each of the NI-Iz radicals attached to the terminal rings is substituted'by an organic radical which does not contain an NHz radical directly attached to an aromatic nucleus and which would not itself render the substituted compound formed unstable to light and oxygen. The improved whitening efi'ect and greater stability can be imparted to white textile materials, particularly cotton, linen, and other cellulosic materials.

In the-laundering of white articles, sodium hypochlorite and similar bleaching agents are often used in the wash or in the rinse to improve the color of the material or to remove fruit, tea, coffee and similar stains. We have found that the whitening efiect produced when using the specified stilbene derivatives of the invention is not impaired by such treatment, as contrasted with the. detrimental effect of such treatment on the stilbene derivatives mentioned earlier in this specification.

The objects achieved in accordance with the invention include the provision of a laundering process for washing and imparting an improved whitening effect of great stability to textile materials; the provision of laundering compositions comprising a combination of a detergent suitable for washing textile materials and a small proportion of an aminostilbene derivative adapted to impart an improved whitening effect of great stability to textile materials; and other objects which will become apparent as the invention is described in more detail hereinafter.

The process aspects of the invention comprise the step of treating textile materials to be washed in an aqueous bath containing a small proportion of an aminostilbene derivative of the kind specified, in the presence of a detergent. This is preferred since it is more convenient to incorporate the aminostilbene derivative in the detergent and the presence of the detergent does not interfere in any way with the enhanced whitening effect of the specified stilbene derivatives.

Instead of adding the specified stilbene derivatives to the wash liquor, they may be applied during the preliminary treatment of the soiled I XN materials which usuall precedes the washing operation proper. It is a customary practice in domestic laundering to allow the soiled materials to soak for several hours, as this removes much of the soluble or loose dirt and facilitates subsequent washing. In commercial laundries a short preliminary soaking treatment is carried out by mechanically agitating the materials for a few minutes in water which is usually made slightly alkaline. This preliminary treatment is called the break. The specified stilbene derivatives may be added to the break.

The detergent promotes cleaning of .the soiled white textile materials by facilitating the removal of material adhering to the textile material. In the treating process of the invention, the whitening of the textile material with the aminostilbene derivative takes place either simultaneously with the washing-detergent action or is followed by the washing-detergent action. In either method, the textile is subjected to the effect of the combination of the detergent and the aminostilbene derivative.

It might be expected that the simultaneous or subsequent washing-detergent treatment would interfere with the absorption of the aminostilbene derivative by the textile, or that the subsequent washing-detergent treatment would remove any absorbed stilbene derivative. This is not the case, however. Instead, the presence of the detergent, along with the particular aminostilbene derivative used in accordance with the invention, results in an unexpected whitening action at the conclusion of the washing process, and this is not destroyed by rinsing or subsequent treatments.

The accumulation of the substantive whitening agents of the invention on the textile material, such as by repeated laundering treatments, is not harmful. It is not possible to over-blue the textile therewith. In this respect the new agents are distinctly different from substantive blue dyes. Any accumulation of the aminostilbene derivatives of the invention on the textile is harmless, not only from the standpoint of appearance immediately imparted to the textile but also from the standpoint of freedom from potential darkening. The stilbene derivatives of the invention do not darken on exposure to air, sunlight, or bleaching agents, such as sodium hypochlorite. Thus, the treated textile material can be laundered repeatedl in accordance with the invention without harmful efiects.

The above defined stilbene derivatives, for example, may be derived by substituting in a diaminobenzoylamino-stilbene sulfonic acid, such as 4:4-dip -aminobenzoylamino stilbene-2:2-disulfonic acid, 4:4-di-p-aminobenzoylamino-stilbene-3:3-disulfonic acid, 4:4-di-p-aminobenzoxylamino stilbene-2:2,6:6-tetrasulfonic acid, one or both amino hydrogen atoms by an organic radical which does not itself contain a terminal NHz radical attached to an aromatic nucleus such as a benzene ring. It is essential that the aminostilbene derivative contain no primary-amino aryl groups in the molecule.

At least some of the aminostilbene derivatives which may be used in accordance with the invention may be illustrated by the following formula:

SOaH SOsH Y CH=CH where X is alkyl, aryl, aroyl, acyl, or carbamyl, and Y is H, alkyl or aryl. In general, the lower aliphatic or aromatic groups are preferred as the X in the above formula. These may be typified by: methyl, ethyl, propyl, isopropyl, butyl, cyclohexyl, phenyl, methylphenyl, dimethylphenyl, benzoyl, methylbenzoyl, dimethylbenzoyl, acetyl, propionyl, butyryl and carbamyl (H2NCO-), methyl carbamyl (HzCNHCO), ethyl carbamyl (H5C2NHCO) and d i e t h y l carbamyl (HsCz) 2NCO) The stilbene derivatives may contain one or more sulfonic acid groups and these may be attached anywhere in the molecule. The stilbene derivative may be of the symmetrical type or nonsymmetrical type. The benzoyl group may be replaced by a corresponding polynuclear aroyl group. Thus, in the broader aspects of the invention, a (non-primary amin0)aroylaminostil- ,bene sulfonic acid is used as the whitening agent. The non-primary amino groups which are directly attached to an aryl group may be secondary (i. e. RNH) or tertiary (i. e. R2N), as long as R does not contain a primary amino (-NHz) group directly attached to any aryl group.

The above defined stilbene sulfonic acids may be used in the form of their salts (i. e. sodium salt) and it is intended that the term acid" appearing herein include the acid itself and also derivatives such as the salts which contain the anion of the acid.

The aminostilbene derivative must be water soluble or dispersible in the presence of a detergent and this will exclude groups which impart thereto non-dispersibility in water.

The aminostilbene derivatives used in accordance with the invention should not contain a group or radical which imparts tinctorial properties (i. e. an actual color producing or chromophorous group) or groups which tend'to discolor upon exposure to light, air, or bleaching agents rivatives which may be used in accordance with I l the invention are:

1. 4:4-di-p-benzoylaminobenzoylamino stilbene-Z :2. -disulfonic acid;

soar

CH=CH 2. 4'z4"-di p acetylaminobenzoylamino-stilbone-2: 2' -disulfonic acid;

SOsH

aswell as'the corresponding metaand ortho com.- pounds, and salts of. the above acids.

The detergents that are used with. the stilbene compound or subsequent thereto or which are: combined with the stilbene compound ina composition, are of the kind suitable for and customarily used in textile laundering practice. The suitable detergents are generally of the organic detergent type.

Thezorganic detergents are regardedby'the art as falling into the soapy and the non-soapy-types; The water dispersible soapy organic detergents are salts ofsoap-forming carboxylic acids such as the fatty acids, rosin acids, and the like. The cation of the water dispersible soap is usually monovalent and usually an alkali metal cation such as sodium.

The non-soapy organic detergents generally are not carboxylate salts. In general, they have in the molecule a. group having hydrophobic properties, such as a long chain alkyl radical, and a group having hydrophillicproperties, such as: a sulfonic group. The non-soapy organic detergents comprise, for example, sulfonated or sulfated high molecular fatty compounds, which are known in the art as a group of non-soapy higher fatty detergents. Some of the various compounds of this type include sodium fatty a1- cohol sulfates known as Gardinols, isethionic acid, hydroxy ethyl sulfonic acid and sarcosine condensation compounds of fatty acid radicals having 8 carbon atoms or more, such as Igepon A; amides of various types, such as Igepon T and. Emco, and Nacconols which are alkali metal alkyl aryl sulfonates.

The expressions soap product and detergent product refer to products in a commercial marketable form comprising primarily soap or the non-soapy organic detergents, or both as the active organic detergent, in admixture with appropriate proportions of water, glycerine, filler, antioxidant, coloring matter, and other soap adjuncts present in large or. small amounts as impurities or additives for special purposes. The fillers or builders which may be included in the soap product or the detergent product are typified by sodium carbonate, sodium silicate, various phosphates, and other well known soap adjuncts.

A preferred embodiment of the invention comprises a composition comprising a detergent,

6 preferably ordinary laundry soap, and; a small amount of: the above. aminostilbenederivative; Thev proportions: of. the; detergent. and aminostilbene derivativev in the composition are determined by various factors such as the particular aminostilbene derivative employed, the nature of the textile material, the nature of the detergent, and the concentration of the detergentv composition which is to be used in the aqueous dispersion or washing solution. As a general rule, less than about 1% of the aminostilbene is required, based on the Weight of the detergent, and proportions ranging from about 0.001% to 0.1% have been found suitable for usualtextile washing procedures;

The. compositions may be in any convenient form, such as tablets or cakes of framed, milled or. convertedsoap; flakes, and powder or granules,- such as spray dried soaps, comprising the amino.- stilbenederivative. In general, the powder or granule-form. is convenient for. general. launderingv purposes.

In; the preparation of the compositions, in accordancewith-the invention, the. aminostilbenederivative may be incorporated with the deter-- gent atany'suitable stage of manufacturing, for example-,in-the final stage in the soap kettle, or. during the crutching or milling of soap. The aminostilbene compound may be added in the formof a solution or suspension in water, or in admixture with other ingredients, such. as perfumes, antioxidants, or any other adjunct to be included in the finalsoap product.

The requisite amounts of aminostilbene compounds in the washing liquor or in the preliminary laundering treatment may vary within' wid'e limits. In general, it is preferred to express this in terms of the amount of textile to be treated, and usually not over about 0.01'% \is necessary,- based on the dry weight of the textile material to be washed. Propertions ranging from 010025 to 0.000175 have been found sufficient to impart an appreciable whitened effect. There is no advantage in using more than is necessary to obtain the White effect and, of course, the amounts used should be less than sufficient to impart a colored effect thereto. The amount need not be larger than 0.05%, based onthe textile: material to achieve a satisfactory whitening. effect. However, since the use: of. excessive quantities of blue-fluorescent sub.- stances does notin general produce over-blueing, which is an objectionable feature of. the commonly used blueing agents, higher amounts,.say upto one per. cent. or-more, maybe used without detriment to the effect produced. Such higher amounts, however, usually serve no useful purpose once the quantity producing maximum whitening effect for a given case has been reached.

If the detergent composition contains 0.01 to 0.075% by weight of the aminostilbene compound and the washing liquor contains 0.25 to 0.75% of the detergent composition, the concentration in the liquor of the aminostilbene compound can be readily calculated.

7 The manner -of applying. the invention in tiles and for imparting a whitening eflect thereto practice is illustrated in the following examples. comprising a detergent suitable for laundering The detergent employed wa ordinary laundry [textiles and from about 0.001% to 1% by weight soap and the aminostilbene derivative was the of an aminoaroylaminostilbene sulfonic acid sodium salt of 4:4 -di-p-acetylamino-benzoylwhich has the following general formula:

S0111 SOaH Y Y 21-1 CH=CH N-X amino-stilbene-2:2 -di-sulfonic acid. Laundry where X is a radical selected from the group compositions were made up therefrom, compris- M consisting of aroyl and acyl radicals and Y is a ing various proportions of the aminostilbene deradical selected from the group consisting of hyrivative. This compound was incorporated in drogen, alkyl radicals of not over four carbon the soap in proportions varying from about atoms, phenyl, methylphenyl and dimethylphenyl 0.003% to 0.06% of the weight of the soap, and radicals.

the resulting soap products were used for wash- 2o 3. A composition suitable for laundering texing white cotton and linen materials in a series tiles and for imparting a whitening effect thereto of comparative tests. The wash liquor was made comprising soap and from about 0.001% to 1% by up by dissolving about 0.4% of each soap prodweight of a benzoylaminobenzoylamino-stilbene uct in hard water. The materials were washed sulfonic acid free from terminal NHz groups atboth at about 40 C. and at the boil, rinsed three tached to an aryl group.

times in clean water and then dried and ironed. 4. A laundering composition comprising soap It was found that in every case the finished maand from about 0.001% to 1% by weight of an terials were of a brilliant white appearance and acetyla n be y o-St 1bcne SulfOnic acid that the whiteness was not noticeably impaired e m terminal z o ps tached to an when the materials were exposed to sunlight for aryl groupprolonged periods. The higher proportions of 5- A c mpo i n i l for la nd rin texthe blue-fluorescent compound gave the best retiles and for imparting a Whitening efiec e o, sults, but even the lowest proportions showed a p s ng Soap and from about 0.001% to 0.1% marked improvement. subjecting the above by W i h of -P- z yl mi z yl miwashed materials to a. sodium hypochlorite bleach ti1be e-2I2 -disulfonic acid. treatment did not darken the color thereof. A COmDOSitiOII Suitable for laundering te The foregoing descriptions of specific embodi- $1165 and for imparting a Whitening effect thereto. ments of the invention are for illustrative pur- Comprising p and from about ii-001% to 0.1% poses only and are not to be construed as limiy W ht o 4I4 -d -pacetylaminobenzoylaminotations of the invention as it is otherwise dis- -diSulfonic acid. closed and claimed herein. In view of the fore- RICHARD THOMAS. going disclosure, variations and modifications thereof will be apparent to one skilled in the art. REFERENCES CITED The invention contemplates all such variations The following references are of record in the and modifications as come within the scope of file of this patent: the appended clalms- UNITED STATES PATENTS I clam: Number Name B g 1. A composition suitable for laundering texe tiles and for imparting a whitening effect thereto 2089413 Fame et a1 1937 comprising soap and from about 0.001% to 1% by FOREIGN PATENTS weight of an aminoaroylaminostilbene sulfonic Number Country D te acid which has the following general formula: 731,558 Germany Feb, 11, 1943 S0311 SOsH X-I l CH=CH I l-X U where X is a radical selected from the group con- OTHER REFERENCES sisting of benzoyl and acetyl radicals and Y is a radical selected from the group consisting of hy- 5 Wench; (3-), publlshed drogen, alkyl radicals of not over four carbon atoms, phenylmethylphenyl and dimethylphenyl pagilililgcal Formulary-Bennett. Vol. 6 (1943) radicals.

2. A composition suitable for laundering tex-

Claims (1)

1. 2. A COMPOSITION SUITABLE FOR LAUNDERING TEXTILES AND FOR IMPARTING A WHITENING EFFECT THERETO COMPRISING A DETERGENT SUITABLE FOR LAUNDERING TEXTILES AND FROM ABOUT 0.001% TO 1% BY WEIGHT OF AN AMINOAROYLAMINOSTIBENE SULFONIC ACID WHICH HAS THE FOLLOWING GENERAL FORMULA: