US3578600A - Stabilization of n-chloro-imides - Google Patents

Abstract

R-S-S-R1

WHEREIN R AND R1 ARE INDEPENDENTLY SELECTED FROM THE GROUP CONSISTING OF ALKYL, ARYL, ARALKYL, AND ALKARYL THE COMBINED CARBON CONTENT OF SUCH GROUPS FALLING WITHIN THE RANGE OF FROM 4-14.
CLEANSING COMPOSITIONS CONTAINING AN N-CHLORO-IMIDE AND A STABILIZING AMOUNT OF A DISULFIDE COMPOUND OF THE FOLLOWING STRUCTURAL FORMULA:

Description

United States Patent 3,578,600 STABILIZATION OF N-CHLORO-lllVIIDES Richard L. Burke, Madison, N.J., assignor to Colgate- Palmolive Company, New York, N.Y. No Drawing. Filed May 29, 1968, Ser. No. 732,87ii

Int. Cl. Clld 7/54 US. Cl. 252-102 11 Claims ABSTRACT OF THE DISCLOSURE Cleansing compositions containing an N-chloro-imide and a stabilizing amount of a disulfide compound of the following structural formula:

R-SSR wherein R and R are independently selected from the group consisting of alkyl, aryl, aralkyl, and alkaryl the combined carbon content of such groups falling within the range of from 4-14.

The present invention relates in general to the stabilization of compositions adapted to perform in use primarily an oxidizing function and, in particular, to the provision of improved stabilizing agents for such purposes.

The utilization of bleaching agents of the hypochloriteliberating type in the formulation of compositions adapted to perform an oxidizing function, e.g., bleaching and detergent compositions, scouring cleansers, etc., is well known in the art being extensively described in the published literature both patent and otherwise. Hypochlorite type bleaching agents, i.e., those bleaching agents which on contact with aqueous media are capable of literating hypochlorite comprise a relatively preferred class of oxidizing agents in view of the comparatively high bleaching levels, i.e., oxidation rates, obtainable therewith. Particularly beneficial results as regards bleaching activity are purportedly obtained with bleaching agents of the N- chlorodmide type. The latter materials, although possessed of a relatively high order of oxidizing efiiciency nevertheless prove somewhat objectionable in view of the manifold problems encountered in connection with attempts to stabilize such compounds against loss of chlorine. As is well known, trichlorocyanuric acid, a powerful oxidizing agent, possesses three labile positive chlorine atoms held only by a nitrogen-chlorine or oxygen-chlorine bond.

In view of the relatively high reactivity characterizing The chlorine atoms present in the trichlorocyanuric acid material as well as the comparativey weak bond of attachment to the trichlorocyanuric acid molecule, there exists a pronounced tendency for reaction with other composition ingredients or with other trichlorocyanuric acid molecules resulting in self decomposition. As will be readily recognized, occurrence of such phenomena to any substantial extent tends to vitiate any possibility of obtaining the favorable bleaching properties normally characterizing such compounds.

In an effort to overcome or otherwise mitigate the foregoing and related problems, considerable industrial activity has centered around the research and development of means whereby to render bleaching agents of the N- chloro-imide type in general adequately stable against chlorine loss with particular emphasis on the isocyanurates. Although much in the Way of meritorious achievement has been accomplished, many of the stabilizing agents thus far promulgated in the art for such purposes are found to be subject to one or more serious disadvantages. As examples of problems frequently encountered in connection with the use of stabilizing agents of the type heretofore provided, there may be mentioned, for exice ample, the failure of such compounds to impart to the oxidizing or bleaching composition the desired level of stabilization for periods of time eonsonate with eflicacious and convenient use. Thus, it is found that the stabilizing capacity of a given compound dissipates rather markedly over relatively short periods of standing, e.g., in periods of time ranging from approximately one to two days under relatively mild conditions of temperature, humidity, etc. Moreover, many of the stabilizer compounds heretofore recommended present serious problems as regards facility of incorporation into the oxidizing composition. Thus, many of such materials may be handled only with difficulty; in addition, in many cases it becomes necessary to resort to the use of additional ingredients for purposes of promoting or augmenting compatibility of the stabilizer compound in the particular oxidizing composition relationship. As Will be recognized, any one of the aforementioned factors may be of such import as to militate against the propriety of using a given stabilizer compound which might otherwise recommend itself.

In accordance with the discovery forming the basis of the present invention, it has been ascertained that a rather specific and delimited class of compounds exhibits synergisti stabilizing action when incorporated into oxidizing compositions containing therein one or more bleaching agents of the N-chloro-imide type.

Thus, a primary object of the present invention resides in the provision of stabilizing agents advantageously adapted for use in connection with oxidizing compositions containing at least one N-chloro-imide bleaching agent wherein the foregoing and related disadvantages are eliminated or at least mitigated to a substantial extent.

Another object of the present invention resides in the provision of stabilizer compounds for bleaching compositions containing one or more N-chloro-imide bleaching agents, said stabilizer compound being capable of effectively stabilizing said N-chloro-imide compound against loss of chlorine.

A further object of the present invention resides in the provision of stabilizer compounds for oxidizing compositions containing at least one N-chloro-imide bleaching agents, said stabilizer compound being capable of effecing chlorine loss for relatively extended periods of time.

Other objects and advantages of the present invention will become more apparent hereinafter as the description proceeds.

The attainment of' the foregoing and related objects is made possible in accordance with the present invention which in its broader aspects includes the provision of compositions adapted to perform an oxidizing function, said compositions containing at least one N-chloro-imide bleaching agent and a stabilizer compound comprising a disulfide compound of the following structural formula:

wherein R and R independently represent alkyl, aryl, aralkyl and alkaryl, the combined carbon content of such groups falling within the range of from 4 to 14. Suitable substituents include, for example, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, phenyl, benzyl, etc.

The disulfide compounds encompansed by the above depicted structural formula are uniformly characterized in exhibiting a pronounced capability to stabilize oxidizing compositions containing an N-chloro-imide bleaching agent for extended periods of time under relatively extreme temperature conditions. Thus, and as will be made manifestly clear in the examples which follow, bleaching compositions containing the disulfide stabilizer exhibit minimal, if not negligible, loss of chlorine upon standing for extended periods of time despite subjection to temperatures on the order of F. By way of contrast, similar compositions, omitting the disulfide stabilizer, ex-

hibited an intolerable level of chlorine loss to the extent that such compositions proved highly inefiicient for even mild cleansing applications.

A further advantage characterizing the disulfide compounds described herein relates to the exceptionally high degree of stabilization against chlorine loss obtainable therewith despite their use in minimal concentrations. In this connection, it is found that concentrations of disulfide on the order of only about 0.001 to about 0.1% by weight of bleach composition sufiice to substantially eliminate any possibility of significant chlorine loss. Optimum concentrations of disulfide will vary somewhat depending upon, of course, the particular use contemplated for the composition being formulated. Thus, for example, in the case of fabric bleaching and washing operations, wherein the concentration of N-chloro-imide compound may fall within the lower ranges, the required concentration of disulfide is correspondingly reduced. In other applications wherein the soil-removal problem may be somewhat more severe,. e.g., as would be the case with scouring cleanser compositions, the concentration of disulfide employed would increase with increased quantities of a N-chloroimide compound. In any event, it is found that beneficial results as regards stabilization of N-chloro-imide bleachcontaining compositions regardless of the particular use contemplated therefor may be obtained when the use of the disulfide compound in amounts sufiicient to yield a mole ratio of disulfide to N-chloro-imide bleaching agent within the range of from about 1/1 to about 1/20 with a range of 1/2 to 1/10 being particularly preferred. Within the foregoing range, it is usually found that increased concentrations of disulfide lead to corresponding increases in chlorine stabilization.

As specific examples of disulfide compounds found to provide particularly beneficial results in the compositions described herein, there may be mentioned in particular and without necessary limitation the following:

diisopropyl disulfide diphenyl disulfide di-n-propyl disulfide The N-chloro-imide bleaching agents contemplated for use in accordance with the present invention are preferably provided in particulate form in a substantially dry state, i.e., devoid of free water; the terminology devoid of free water" should not, however, be interpreted as excluding the presence of water of crystallization or hydration. In general, it is found that optimum realization of the improvements described herein attend those procedures wherein the N-chloro-imide compound is employed within certain particle size limitations; preferably the major portion of the N-chloro-imide compound (60 to 90%) should be that which passes through a 200 mesh screen. As specific examples of N-chloro-imide compounds found to be particularly suitable in the practice of the present invention, there may be mentioned without necessary limitation trichloroisocyanuric acid (TCCA), dichloroisocyanuric acid (DCCA), sodium dichloroisocyanurate, potassium dichloroisocyanurate, etc., as well as mixtures of two or more of such compounds.

The N-chloro-imide compound may be employed in concentrations varying over a relatively wide range, the specific concentration selected being dictated in large part by the severity of the cleaning problem likely to be encountered by the composition being formulated. In any event, it is found that satisfactory negotation of the broad spectrum of cleaning problems likely to be confronted can be attained by the use of the N-chloro-imide compound in amounts sufficient to yield a concentration within the range of 0.1 percent to 90 percent and higher and preferably from percent to 90 percent and higher by weight of total composition of laundry bleaching detergents and from 0.1 percent to 5 percent by weight of composition of cleansers.

The disulfide compound in combination with the N- chloro-imide bleaching agent comprise the critical components of the composition herein described. The exceptional stability of compositions prepared with same against decomposition on aging under relatively severe conditions of storage, i.e., conditions which would otherwise in the normal course of events give rise to inordinantly high levels of N-chloro-imide decomposition and corresponding loss of chlorine is highly advantageous from a fur ther standpoint. The decomposition products of many N- chloro-imide bleaching agents are highly corrosive; thus, considerable care must necessarily be exercised as regards storage of compositions which tend to decompose, The instant compositions tend to eliminate problems associated with corrosion of metallic containers in view of the significant reduction in chlorine loss. Moreover, the corresponding reduction in risk of handling is of paramount importance in connection with personal safety.

The N-chloro-imide compound stabilized in accordance with the present invention may be employed in any substantially dry composition in which the N-chloro-imide compound is otherwise suitable for use, such as washing, bleaching, sterilizing and disinfecting compositions. Thus, the N-chloro-imide bleaching agent/disulfide stabilizer systems may be utilized in admixture with detergent or surface active materials which exhibit substantial stability in the presence of the N-chloro-imide bleaching agent. Detergent materials contemplated for use in accordance with the present invention encompass a relatively Wide range of materials. The particular material selected may be of the soap or soapless variety. The latter materials may be designated as water-soluble salts of organic reaction products having in their molecular structure an anionic solubilizing group such as SO H, SO H, COOH and PO H and an alkyl or aralkyl radical having about 8 to 22 carbon atoms in the alkyl group. Suitable detergents are anionic detergent salts having alkyl substituents of 8 to 22 carbon atoms, such as: water-soluble sulfated and sulfonated anionic alkali metal and alkaline earth metal detergent salts containing a hydrophobic higher alkyl moiety, such as salts of higher alkyl-mono or polynuclear aryl sulfonates having from about 8 to 18 carbon atoms in the alkyl group which may have a straight or branched structure, e.g., sodium dodecylbenzene sulfonate, magnesium tridecylbenzene suufonate, lithium or potassium pentapropylene benzene sulfonate; alkali metal salts of sulfated condensation products of ethylene oxide (e.g., 3 to 20 and preferably 3-10 mols of ethylene oxide per mol of other compound) with aliphatic alcohols containing 8 to 18 carbon atoms, e.g., sodium nonyl phenol pentaethoxamer sulfate and sodium lauryl alcohol triethoxamer sulfate; alkali metal salts of sulfated alcohols containing from about 8 to 18 carbon atoms, e.g., sodium lauryl sulfate and sodium stearyl sulfate; alkali metal salts of higher fatty acid esters of low molecular Weight alkylol sulfonic acid, e.g., fatty acid esters of the sodium salt of isethionic acid; fatty ethanolamide sulfates; fatty acid amides of amino alkyl sulfonic acids, e.g. lauric acid amide of taurine; alkali metal salts of hydroxy alkane sulfonic acids having 8 to 18 carbon atoms in the alkyl group, e.g., hexadecyl alphahydroxy sodium sulfonate. Particularly preferred for use herein are the olefin sulfonates. In gen eral these organic surface active agents are employed in the form of their alkali metal salts or alkaline earth metal salts because such salts possess the requisite stability, water solubility, and slow cost essential to practical utility.

Suitable water-soluble, higher fatty acid salts which are used in conjunction with the foregoing anionic detergents include alkali metal salts of saturated, unsaturated, or mixtures of unsaturated and saturated, fatty acids containing from about 8 to about 18 carbon atoms in the molecule such as: sodium caprate, sodium laurate, sodium myristate, sodium palmitate, potassium oleate, sodium stearate, sodium and potassium salts of tallow fatty acids,

sodium and potassium salts of coconut oil fatty acids, and the like.

Generally, a water-soluble higher fatty acid salt will be added to compositions of the invention as a salt. However, a water-soluble higher fatty acid salt can also be formed in situ by adding stoichiometric amounts of the desired fatty acid and the desired alkaline hydroxide directly to a composition; or alternatively, by adding a desired fatty acid or fatty acid mixture directly to a heavyduty detergent composition where the normal alkalinity desirable in such compositions is sufficient to form the water-soluble, higher fatty acid salt.

It is essential, of course, that the stabilized, N-chloroimide bleach material be maintained in substantially dry condition. Accordingly, it is recommended that such compositions be packaged in moisture impermeable containers such as containers fabricated from glass, metal, metal foil, metal foil-covered paper board, etc. The latter material proves particularly effective in view of its light weight and resilient character.

The compositions of the present invention are preferably provided in particular form, the particles having an average particle size of less than about mesh. Within this range optimum particle size depends for the most part upon the use contemplated for the product formulated. For example, in the case of abrasive cleansers, the particle size is preferably less than about 200 mesh. In contradistinction, in the preparation of spray-dried compositions, the recommended particle size is such that substantially the entire product passes through a 10 mesh sieve being retained on a 100 mesh sieve.

The nature of the auxiliary ingredients included in the basic composition, i.e., the disulfide stabilizer and N- chloroimide bleaching agent depends to a great extent upon the ultimate use contemplated for such compositions. Typically, a substantially dry abrasive cleanser prepared in accordance with the present invention would comprise the N-chloro-imide compound, the disulfide stabilizer, and a major proportion of finely divided, water insoluble siliceous abrasive such as silica, feldspar, pumice, volcanic ash, diatomecous earth, bentonite, talc, etc., as well as mixtures of two or more of the foregoing materials.

In the preparation of water soluble bleaching and detergent compositions, it is found that particularly beneficial results are obtained with the employment of the detergent compound in amounts ranging up to about 60%, i.e., from 060% and preferably from about to about 40% by weight of the composition. Any of the conventional adj'uvants customarily employed in the preparation of bleaching and detergent compositions may likewise be included such as fluorescent brighteners, water soluble inorganic and organic builder salts, the latter being employed in amounts ranging up to about 95%, i.e., 095% with a range of from about 50 to about 95% by weight of the composition being preferred. Suitable builders include, for example,

Trisodium phosphate,

Tetrasodium pyrophosphate,

Sodium acid pyrophosphate,

Sodium tripolyphosphate,

Sodium monobasic phsophate,

Sodium dibasic phosphate,

Sodium hexametaphosphate,

Sodium silicates, SiO /Na O of 1/ 1 to 3.2/1 Sodium carbonate,

Sodium sulfate,

Borax,

Nitriloacetic acid trisodium salt,

Ethylene diamino tetraacetic acid tetrasodium salts, etc.

Mixtures of two or more inorganic or organic salts can be used, as can mixtures of inorganic and organic salts.

Particularly preferred herein are water-soluble, alkali metal polyphosphate builder salts. These salts form watersoluble complexes with calcium and magnesium ions found in hard water and thereby prevent the formation of insoluble salts which tend to deposit upon textiles during a Washing cycle. Further, such phosphates enhance the detersive efficiency of anionic detergents, aid in controlling sudsing and powders and aid in keeping soil suspended in the washing bath after its removal from the soiled textiles.

Various other materials may be included in compositions of the invention. Examples thereof are the higher fatty acid amides such as coconut or lauric monoethanolamide, isopropanolamide and the like; hydrotropic solubilizing agents such as xylene or toluene sulfonates; organic solubilizing agents such as ethanol, ethylene glycol and hexylene glycol; sodium carboxymethylcellulose and polyvinyl alcohol antiredeposition agents; optical and fiuorescent brightener materials; coloring agents; corrosion inhibiting agents; germicides; perfumes, bluing agents; and the like.

Preferred compositions advantageously contain a hydrophobic colloidal cellulosic soil-suspending agent which is soluble or dispersible in water also. The joint use of the combination of the cellulosic compound and polyvinyl alcohol is particularly effective for soil-suspension properties during the washing of a variety of fabrics, including both cotton and synthetic fibers such as nylon, Dacron and resin-treated cottons. The mixture is used preferably in a total amount of 0.1 to 2 percent by weight of the solids. Preferred cellulosic compounds are the alkali metal salts of a carboxy lower alkyl cellulose having up to 3 carbons in the alkyl group, such as the sodium and potassium salt of carboxymethylcellulose. Suitable salts are sodium carboxyethylcellulose; the cellulose sulfates and lower alkyl and hydroxyalkylcellulose ethers such as methyl-, ethl-, and hydroxyethylcellulose.

The compositions described herein are particularly and advantageously adapted for use in connection with the bleaching and washing of stained and/or soiled fibrous products, the latter including fabrics, garments, household laundry and the like. In actual use, the stabilized composition is dissolved in aqueous media whereby to achieve uniform dispersion of the involved ingredients. The aqueous solution thus obtained may be then contacted with the material to be bleached. The provision of the bleach ing composition in aqueous form affords the advantage that any possibility of uneven or localized bleaching and possibly fiber damage is minimized, if not avoided, whereas the use of the bleaching composition in dry form presents significant risk of injury to the fabric under treatment. Thus, effectuation of oxidative bleaching and washing in accordance with the present invention preferably comprises comrningling the stabilized N-chloro composition with Water in amounts consonant with efiicacious bleaching action and thereafter contacting the resulting aqueous mixture with the material to be bleached. Moreover, optimum bleaching action obtains in those instances wherein the bleaching treatment is carried out within a short time following formulation of the aqueous bleaching solution, e.g., within about 3 minutes thereafter. Alternatively, the oxidative treatment prescribed by the present invention may also be accomplished by first immersing the textile in an aqueous medium and thereafter introducing the composition comprising the disulfide stabilizer and N-chloro-imide bleaching agent.

It will be understood, of course, that the concentration of bleaching composition employed may be varied within relatively wide limits depending upon the nature of the oxidation problem encountered. Thus, rather concentrated solutions are permitted when treating stained ceramics since the possibility of damage to the ceramic material is highly remote. In such instances, the bleaching composition may be applied as such to the selected surface to be treated and thereafter adding water in amounts sufficient to form a paste or slurry of the desired consistency. As will be recognized in such procedures, formation of the aqueous bleaching medium occurs in the presence of the material to be treated.

The following examples are given for purposes of illustration only and are not to be considered as necessarily constituting a limitation of the present invention.

A series of cleanser compositions having the following compositions is prepared Example N0.

Ingredients 1 2 3 Trichloroisocyanuric acid (TC CA), [)Ql'L'0llt 0. 50 0. 50 0. 50 Sodium bromide 0. 70 O. 70 0. 70 Trisodium phosphate, anhydrous. 3. J5 3. H5 3. J5 Detax, 55% A l 5. 45 5. 45 5. 45 IIeliogen dye. 0. .25 0. l5 0. .25 Silex I 89.15 88. J5 88. 80

Diisopropyl disulfide l l 0. Ht, Isobornyl acetate l U. 20 0. 2t)

1A composition consisting of, by weight: on, linear alkylbenzen sulfonate, sodium; sodium Silicate; .0149; lphol (mixture of orthocresol, isopropyl alcohol, IIaPOi and soda ash); 2.0", water; balance sodium sulfate.

The isobornyl acetate is not in itself a stabilizer but is added to expedite uniform and homogenous dispersion of the involved ingredients and particularly the disulfide stabiiizer. In order to determine the stability of the aboveidentified compositions against loss of chlorine upon standing each of such compositions is allowed to stand for predetermined periods of time at a temperature of 140 F. Measurements to determine chlorine content are taken at the intervals specified in the following table:

TABLE 1 Stability at 140 I ltl't'l'lll available chlorine Negligible Negligible 38 38 1 Determination of available chlorine content is determined via tWo tltiosulphate titrations which are effected by first storing the sample 10 minutes in Water before addition of pot .ium iodide or sulfuric acid. This method of determining the available chlorine content is somewhat more reliable sinec trichlorocyanuric acid (TCCA) exhibits a tendency to degrade to a. form comprising ineticctivc bleaching species. However, normal thiosulpbate titration \\'ill in most instances indicate stability of the trichloroisocyanuric acid despite such degradation. However, the titration method employed in these instances reflects quantatively only that proportion of trichloroisocynnuric acid which has not undergone decomposition.

As the data in the above table makes manifestly clear, the presence of the disulfide stabilizer imparts to the composition an exceptional level of chlorine stability. As will be apparent, upon lapse of a period of 3 days, the disulfide-stabilized composition exhibits a rather slight loss in available chlorine, i.e., on the order of about 9%. However, it is significant to note that the available chlorine level of 0.38. tabulated after a lapse of 3 days standing, remained constant thereafter. The net loss in available chlorine thus approximated 9%. In contradistinction, each of the cleanser compositions devoid of the disulfide stabilizer exhibits an intolerable loss of available chlorine after a period of only 3 days. In addition, the available chlorine level continued to dlminish significantly with increased standing periods. In view of the relatively severe testing conditions employed, i.e., temperature, the improved stabilization made possible via the use of the disulfide compounds is of the first order of significance.

EXAMPLES 4-6 Examples 1 to 3 are repeated except that in each case, 2.7% by weight of sodium sulfate decahydrate is added to the respective compositions, the addition being made for purposes of enabling evaluation of the stability of the compositions in question in the presence of significant quantities of moisture. Thus, under the conditions employed in the testing, the bound water content of the sodium sulfate is released. The results obtained establish til) 8 clearly the superior stabilizing action of the disulfide compound i.e., the chlorine loss of the disulfide-stabilized composition compared favorably with that summarized in connection with Example 3 despite the presence of significant quantities of moisture.

EXAMPLES 78 TABLE 2 Stability at 140 F.

Percent available chlorine Days 0 3 6 Example No;

7 tconttol) .50 l2 Negligible S .46 33 EXAMPLES 9-102 Examples 3 and 8 are repeated except that in each case, the concentration of disulfide stabilizer is increased to 0.1% by weight of total cleanser composition. In each instance, excellent results are obtained with respect to chlorine stability. Moreover, the diisopropyl disulfide exhibited a slight decrease in stabilizing efiiciency which may well have been attributable to experimental error inherent to a certain degree in the system employed. However, it may be more likely that the initial stage of limiting concentration values in the case of this particular species of stabilizer may have been reached. Thus, it is usually found that increased concentrations of stabilizer give rise to corresponding increases in stabilization efliciency within certain limitations. Thus, beyond particular concentration values, it may be found that stabilizing efiiciency is actually diminished or otherwise deleteriously affected.

In practical terms, the implications suggested by the above data cannot be overemphasized. As explained hereinbefore, it is of critical importance to the efficacy of a given bleach composition that exceptional stability against chlorine loss be obtainable despite protracted periods of storage under varying conditions of temperature, humidity, etc, Thus, it is inevitable that the cleanser composition during periods of transport, storage, and/or use, will be subjected to conditions conducive to moisture pickup. This situation obtains despite the precautionary matters observed as regards packaging, handling, etc. Thus, one of the particularly beneficial advantages made possible by the present invention becomes clearly evident namely, the exceptional stability against chlorine loss despite the presence of moisture. Improved stability against chlorine loss presents manifold advantages from an economic standpoint. Thus, the effectiveness of bleach compositions being critically dependent upon available chlorine content becomes seriously impaired when stored for even nioterately extended periods of time under relatively mild conditions of temperature and humidity in the absence of effective stabilizing agents. In order to compensate for the net loss in available chlorine content, it becomes necessary in practice to resort to the use of increased proportions of bleach compositions. In view of the lower volume efiiciency characterizing the nonstabilized cleanser materials, the added cost increment necessarily attending the use of such materials may be prohibitive.

Results similar to those described in the foregoing examples are obtained when the procedures described therein are repeated but employing in lieu of the specific disulfide stabilizers exemplified, the following: diethyl disulfide; di'n-butyl disulfide; diisobutyl disulfide; di-n hexyl disulfide and dibenzyl disulfide. In each case, an exceptionally high order of chlorine stability obtains despite subjection to temperatures on the order of 140 F.

The improved chlorine stabilization result likewise obtains when the exemplified procedures are repeated but employing in lieu of trichloroisocyanuric acid (TCCA), one or more of dichloroisocyanuric acid, sodium dichloroisocyanurate and potassium dichloroisocyanurate. In each instance, superior stabilization against chlorine loss is obtained despite the use of the disulfide compound in minimal concentrations, i.e., concentrations falling within the range of 0.001% to 0.1% by weight of total composition. It should be emphasized that the concentration of disulfide employed is critical solely from the standpoint that it be present in amounts sufiicient to stabilize against loss of chlorine. Apart from this particular requirement, concentration selection may vary within relatively wide limits. Moreover, unusually excessive quantities, i.e., on the order of by weight of composition should be avoided in order to minimize any possibility of deleteriously affecting the N-chloro-imide compound.

The composition contemplated by the present invention may comprise simply a mixture of the N-chloroimide compound and disulfide stabilizer, the latter being employed within the mole ratio range hereinbefore specified. Thus, highly useful bleaching, disinfecting, etc., compositions may be so formulated. The superior stabilizing function of the disulfide compound is particularly manifest in such compositions, evaluative testing in connection therewith in the manner therein exemplified indicating chlorine losses of 10-12% and less after 6-9 days standing at temperature of 140 F.

The present invention has been described with respect to certain preferred embodiments thereof and there will become obvious to persons skilled in the art other variations, modifications and equivalents which are to be understood as coming within the scope of the present invention.

What is claimed is:

1. A cleansing composition stabilized against loss of chlorine consisting essentially of (a) an N-chloro-imide bleaching agent selected from the group consisting of dichloroisocyanuric acid, trichloroisocyanuric acid, alkali meal salts thereof, and mixtures thereof, and (b) a disulfide compound of the following structural formula:

wherein R and R are independently selected from the group consisting of alkyl, phenyl and benzyl, the combined carbon content of such group falling within the range of 4-14, and said disulfide being present in amounts sufiicient to stabilize said N-chloro-imide against loss of chlorine,

2. A composition according to claim 1 wherein said N-chloro-imide is trichloroisocyanuric acid.

3. A composition according to claim 1 wherein said N-chloro-imide is dichloroisocyanuric acid.

4. A composition according to claim 1 wherein N-chloro-imide is sodium dichloroisocyanurate.

5. A composition according to claim 1 wherein N-chloro-imide is potassium dichloroisocyanurate.

6. A composition according to claim 1 wherein disulfide is diisopropyl disulfide.

7. A composition according to claim 1 wherein disulfide is diphenyl disulfide.

8. A composition according to claim 1 wherein disulfide is di-n-butyl disulfide.

9. A composition according to claim 1 wherein disulfide is diisobutyl disulfide.

10. A composition according to claim 1 wherein said disulfide is dibenzyl disulfide.

11. A composition as defined in claim 1 wherein the mole ratio of disulfide compound to N-chloro-imide bleaching agent ranges from 1/1 to 1/20.

said

said

said

said

said

said

References Cited UNITED STATES PATENTS 3,278,443 10/1966 Bright et a1. 252-102X MAYER WEINBLATT, Primary Examiner US. Cl. X.R. 252-95, 99, 187