CA1111609A - Peroxygen bleaching and compositions therefor - Google Patents

Abstract

ABSTRACT:
A process of removing soil and/or stains from fabrics by immersing the fabrics in a peroxygen bleach bath containing as a peroxygen activator an aromatic sulfonic anhydride of the formula R1SO2-O-SO2R2, wherein each of R1 and R2, which may be alike or different, is an aliphatic radical selected from the class consisting of an alkyl radical of 1 to 18 carbon atoms; a cycloalkyl radical of 3 to 7 carbon atoms and a aromatic ring system selected from the class consisting of a phenyl group, taken together are an o-phenylene group, a naphthyl group, taken together are an o-napthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the class consisting of nitrogen, oxygen and sulfur, said aromatic groups optionally bearing 1 to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine.
Aromatic is used herein its modern sense to signify an organic ring system having aromatic character including both aromatic hydrocarbon and heterocyclic ring systems.
Also describe are dry blend composition containing the bleach bath components.

Description

PE_XYGEN BLEACHING AND COMPOSITIONS THEREFOR_ This invention relates to active oxygen compo-sitions, In particular, the invention is concerned with activated peroxygen compounds and their appli-cation to laundering operations.
The use of bleaching agents as laundering aidsis well known. In factr such entities are consid-ered necessary adjuncts for cleaning today's fabrics which embrace a wide spectrum of synthetic, natural and modified natural fiber systems, each differing in washing characteristics.
Laundry bleaches generally fall into one of two categories; active oxygen-releasing or peroxygen and active chlorine-releasingO Of the two, the chlorine ; 15 bleach is more likely to react with the various com-ponents of a detergent washing formulation than per-oxygen bleaches. Moreover, fabrics treated with chlor-ine bleaches exhibit significant loss of strength and depending on the frequency of bleaching, the useful 20 life of the cloth may be appreciably reduced; with dyed fabrics, colors are often degraded. Another objection to chlorine bleaches is their pronounced tendency to cause yellowing, particularly with synthetics and resin treated fabrics. Peroxygen bleaches are sub-~5 stantially free of such adverse side effects~
Despite their many advantages, bleachlng agentsof the active oxygen-releasing type are as a class not optimally effective until use temperatures ex-ceed about 85~C, usually 90C, or higher. This rather critical temperature-dependency of peroxygen bleaching agents and especially the persalt bleaches such as sodium perborate poses a rather serious drawback since many household washing machines are now being operated at 5 water temperatures less than about 60~C, well below those necessary to render bleaching agents such as the perbor-ates adequately effective. Althou~h the near boiling washing temperatures employed in Europe and some other countries favor the use of peroxygen bleaches, it can be 10 expected that such temperatures will be lowered in the interest of conserving energy. Conse~uently, where a comparatively high order of bleaching activity at reduced temperature is desired, resort must be had to chlorine bleaches despite their attendant disadvantages, that is, 15 impairment of fabric strength, fabric discoloration, and the like.
In an effort to realize the full potential of per-oxygen bleaches, such materials have been the focus of considerable research and development effort over the 20 yearsO One result of these investigations was the finding that certain substances, activators as they are usually called, have the capacity of amplifying the bleaching powder of peroxygen compounds below about 60C
where many home washing machines are commonly operated, 25 or preferably operated. Although the precise mechanism of peroxygen bleach activation is not known, it is believed that activator-peroxygen interaction leads to the formation of an intennediate species which consti-tutes the active bleaching entity. In a sense, then, the 30 activator-peroxygen component functions as a precursor system by which the in place generation of species providing ef~ective bleaching means is made possible.
Although numerous compounds have been proposed and tested as peroxygen bleach activators, a satisfactory 3~ candidate has thus far not been forthcoming. Perhaps the primary objection is the failure to provide the desired degree of bleaching activity within the limitations .

:

imposed by economically feasible practice. Thus, it is often necessary to utilize the activator compound in inordinately high concentrations in order to achieve satisfactory results; in other instances, it is found that a given activator is not generally applicable and thus may be used advantageously only in conjunction ~ith rather specific and delimited types of peroxygen bleach-ing agents. Other disadvantages characterizing many of the activator compounds thus far contemplated include, l0 for example, the difficulties associated with their incorporation into detergent powder compositions in-cluding stability problems and short shelf life. Since many of the activators are liquids under normal condi-tions, the blendin~ of such materials into solid products lS is not practical, at least so far as home application is concerned. Moreover, ancillary techniques specifically devised for purposes of facilitating activator-detergent powder blending in such instances are often economically prohibitive, the results obtained failing to justify the involved costs.
Classes of compounds which are representative of prior art activators for peroxygen bleaches include carboxylic acid anhydrides disclosed in U.S. Patents

2,284,477, 3,532,634 and 3,298,775; carboxylic esters 25 disclosed in U.S. Patent No. 2,955,905; N-substituted, N-acylnitrobenzenesulfonamides disclosed in U.S. Patent No. 3,321,497; N benzoylsaccharin disclosed in U.S~
Patent No. 3,886,078; N-acyl compounds such as those described in U.S. Patent No. 3,912,648 and 3,919,102 and 30 aromatic s~lfonyl chlorides disclosed in Japanese Patent Publication No. 90980 of November 27, 1973.
While certain of these activators are effective in varying degrees, there is a continuing need for candidate compounds of improved performance and properties~
According to the process of the present invention the bleaching capacity oE pero%ygen bleaches at low temperatures is increased by contacting them with a sulfonic anhydride activator compoun~ and the provision of bleaching compositions containing such components and the use thereof alone or in conjunction with conventional laundering processes and materials to treat soiled and/or S stained fabrics constitutes the principal object and purpose of the invention. Other objects and purposes will become apparent subsequently herein.
The sulfonic anhydride activator compounds afore-said can be depicted by the following formula:
0 R S02~0--S02R
wherein each of R1 and R is an aliphatic radical which may be alike or different selected from the class consisting of an alkyl radical of 1 to 18 carbon atoms;
a cycloalkyl radical of 3 to 7 carbon atoms and an aro-15 matic ring system selected from the class consisting of a phenyl group, taken together are an o-phenylene group, a naphthyl group, taken together are an o-naphthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of 20 which 1 to 2 are heteroatoms selected from the class con-sisting of nitrogen, oxygen and sulfur, said aromatic groups optionally bearing 1 to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic 25 carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine. Aromatic is used herein in its modern sense to signify an organic ring system having aromatic charac-ter including both aromatic hydrocarbon and heterocyclic ring systems.
Another proviso attached to the characterization of the herein activators is that they exhibit sufficient solubility in the bleaching system in order to provide the requisite degree of activation for the active oxygen-releasing bleaching agent. For instance, filling up 35 the free positions in the aromatic ring system with bulky substituents could give rise to a derivative of low solubility. The particular type of substituent may also be a factor affecting the solubility factor.
~xemplary aromatic sulfonic anhydride activators falling within the ambit of the general formula and suitable for practicing the invention are:
Benzenesulfonic anhydri~e o-Toluenesul~onic anhydride p-Toluenesulfonic anhydride 2-Chlorobenzenesulfonic anhydride m-Toluenesulfonic anhydride 2-Mesitylenesulfonic anhydride Octadecylbenzenesulfonic anhydride Octylbenzenesulfonic anhydride p-Nitrobenzenesulfonic anhydride Anhydride of o-Benzenedisulfonic acid ~5 2,4-Dimethylbenzenesulfonic anhydride Anhydride of 1,2-Naphthalenedisulfonic acid p-Butoxybenzenesulfonic anhydride n-Butylbenzenesulfonic anhydride p-Bromobenzenesulfonic anhydride 2,4-Xylenesulfonic anhydride 4-bromo-3-nitrobenzenesulfonic anhydride p-Ethoxybenzenesulfonic anhydride 4-Chloro-3-nitrobenzenesulfonic anhydride 2,4-Diethylbenzenesulfonic anhydride 2,3,4-Trichlorobenzenesulfonic anhydride 2,3,5-Triisopropylbenzenesulfonic anhydride p-Undecylbenzenesulfonic anhydride Anhydride of 2,3-Naphthalenedisulfonic acid The herein sulfonic anhydrides belong to a known chemical class, the description of which is set forth in the technical literature. For instance, in Acta. Chem.
Scand. 15, 1507 (1961) there is described the preparation of arylsulfonic anhydrides by reaction of the requisite aromatic hydrocarbon with sulfur trioxide in accordance with the following scheme:
2RH -~ 3SO3 ~ (RSO~)2O ~ Fl2SO4 Another procedure is the reaction of an arylsulfonyl 6,~

chloride with moisture free oxalic acid as disclosed in J. Org~ Chem. 12, 275 (1947). This reaction using benzenesulfonyl chloride proceeds as follows:
2C6~5SO2Cl+(COOH)2 -~ (C6H5SO2)2O+2HCl~COfCO2 5 The aforecited reaction schemes are generally applicable to the synthesis of symmetrical aromatic sulfonyl anhy-drides of the invention.
A stil] further method of synthesis consists in re-acting the requisite sulfonyl chloride and silver sulfo-~0 nate in accordance with the following equation:
R so2R~-+ AqlOSO2R + R1SO20SO2R2 + AgCl In carrying out the preparation, the acid chloride and silver salt are placed in a solvent and the mixture al-lowed to react. Stirring or other agitation means is 15 employed to aid dissolution and maintain the reaction in a homogeneous state. Reaction temperatures are desirably restricted to about room temperature although tempera-tures up to about 100C can be employed. After the reaction i5 complete, the silver chloride is removed 20 using any of the typical separation techniques, for example filtration, centrifugation or the like. The filtrate is evaporated leaving a solid residue of the sulfonic anhydride which is normally of sufficient purity whereby it can be used directly in peroxygen bleaching.
Examples of solvents for carrying out the reaction include any of the usually liquid, relatively inert organic liquids and in this connection the aliphatic chlorinated hydrocarbons are especially suitable, the chlorinated lower alkanes such as dichloromethane being 30 preferred. For further details and information on the preparation of the sulfonic anhydrides as above de-scribed, reference is made to J. Prakt. Chem. [27], 128 65 (1930).
The condensation of a sulfonyl chloride with a 35 silver sulfonate to produce sulfonic anhydrides is an organic synthesis reaction o~ remarkable scope and general applicabi]ity. In fact, it appears to be limited only with respect to the availability of reactants.
There are, however, disclosed in the chemical journals, the description and preparation of a veritable host of organic sulfonyl chlorides and organic sulfonates and since their functions ar~ readily interconvertible, the disclosure of one reactant is in effect a disclosure of the other. Accordingly, a great many anhydrides includ-ing both symmetrical and unsymmetrical types, can be prepared falling within the scope of the formula wherein 10 Rl and R2 can be varied extensively not only as regards the basic hydrocarbon and heterocyclic radicals but also as regards substituents attached thereto such as for instance chlorine, bromine, fluorine, alkoxyl, alkyl, nitro, cyano, carboxamido, hydroxyl, sulfol or any substituent which does not interfere with the novel and basic characteristics of the sulfonic anhydride as an activator for peroxygen. Where there are C12-C1~
alkyl groups present, the resulting sulfonic anhydride will not only function as a peroxygen activator but also 20 exhibit detergent properties owing to the presence of the surface active higher alkyl radicals. Examples of sulfonic anhydrides herein which can be synthesized by the aforedescribed reaction from known sulfonyl chlorides and/or silver salts of sulfonic acids are listed below.
Symmetrical Alkyl Sulfonic Anhydrides (CH3S02)20 (Iso-C3H7S02)20 (n C4HgS02)2 (CF3S02)20 (C6H13s02)2 (C7H15S02)2 (C10H21S2)2 (CgH19CHN02S02)20 (C12H25s02)2o ( 16 33 2)2 (C2H5CHClcH2s02)2 (c3H7cBr~lo2so2)2o (CHC12CH2CHClCH2S02)2o (C4FgS02)2O
(C2H5CHOHCH2S02)20 (C2H5CF2CF2S02)20 (CF3CBrFSO2)2O
(CH3CHClSO2)2O
(CH2MeOCH2SO2)2O
(CF3CHFSO2)2O
(CH2Phc~2so2)2 (C8F17SO2)2O
Unsymmetrical Alkyl Sulfonic Anhydrides CH3So20So2c3H7 C4HgCHClCH2S020S02C2H5 CHC12CH2CHClCH2CHClCH2S020S02C3H7 C5H11CBrNO2so2o~o2c4H9-n CloH2lso2oso2c7H15 C2H5S020S02CBrFCF3 nC4HgS020S02CHFCF3 cH2Brso2oso2c2H5 CF3So20So2c 1 oH2 1 C7H5S020S02CH2Br C 8 F 1 7S2 os 2 CH 3 C8F17so2o~o2c2 5 C2H5CF2cF2s02oso2c4H9 Cycloalkane Sulfonic Anhydrides (C3H5SO2)20 (C5HgSO2)2O
( 6 11S2)2 CsH9so2oso2c6Hl 1 (4-MeC6H10SO2)2 4-MeC6Hl oS2S2CSH1 1 (2-ClC6HloSO2)2O
( 7 13 2)2 C7H13so2oso2c6Hl1 1-OHc7Hl2sO2oso2c6H1l Unsym~etrical Aryl and Other Sulfonic AnhydrideS
CH3So20S02c6H5 C2H5SO2Oso2c6H4 P C2H5 n-C3H7SO2O~o2c6H4 P CF3 m-Cl-C6H4S2S2C6H4 P CH3 C~2H25-c6H4sO2oso2c6 5 2~4-cl2-c6H3so2oso2c6 4 P 3 ( ~so~o (IGL so ~o ( ~ 50 ~ O ~ 50205~
.20 C16H3~S020S0 Sulfonic anhydrides of the invention which have given excellent results as a peroxygen activator are those members of the formula wherein each of R1 and R2 is lower alkyl and fluorinated lower alkyl, phenyl, 30 lower alkylated phenyl and chlorinated phenyl. By lower alkyl is meant an alkyl radical of from 1 to about 4 carbon atoms.
The sulfonic anhydrides herein are characterized by comparison of melting points with the literature in 35 the case of the known compounds and in general by ele-mental analysis and NMR and IR spectroscopy.
In accordance with the :invention, ].ow temperature bleaching, (that is below about 60~C) of stained and/or soiled fabrics is effected by contacting them with a solution containing a sulfonic anhydride activator herein and an active oxygen-releasing compound. The active ox~gen-releasing compounds include such peroxygen compounds as hydrogen peroxide or those peroxygen com-pounds that liberate hydrogen peroxide in aqueous media.
Examples of such peroxygen compounds are urea peroxide, alkali metal perborates, percarbonates, perphosphates, 0 persulfates, monopersulfates and the like. Combinations of two or more peroxygen bleaches can be used where desired. The same holds true in the case of the acti-vators. Although any number of peroxygen compounds are suitable in carrying out the invention, a preferred compound is sodium perborate tetrahydrate, since it is a readily available commercial product. Another suitable persalt is sodium carbonate peroxide.
Sufficient peroxygen compounds to provide from about 2 parts per million ~ppm) to 2,000 ppm active oxygen in solution are used. For home bleaching appli-cations, the concentration of active oxygen in the wash water is desirably from about 5 to 100 ppm, preferably about 15 to 60 ppm. Sodium perborate tetrahydrate, the preferred peroxygen compound, contains 10.4~ active oxygen. The actual concentration employed in a given bleaching solution can be varied widely, depending on the intended use of the solution.
The concentration of the sulfonic anhydrides in the bleaching solution depends to a large extent on the concentration of the peroxygen compound which, in turn, depends on the particular use for which a given compo-sition is formulated. Higher or lower levels can be selected according to the needs of the formulator. Over-all, increased bleaching results are realized when the active oxygen of the peroxygen compound and sulfonic an~
hydride are present in a mole ratio in the range of from about 20:1 to 1:3, preferably from about 10:1 to lol~

Activation of the peroxygen ble~ches is generally carried out in aqueous solution at a pH of from about 6 to about 12, most preferably 8.0 to 10.5. Since an aqueous solution of persalts or peracids is generally 5 acidic, it is necessary to maintain the requisite pH
conditions by means of buffering agents. suffering agents suitable for use herein include any non-inter-fering compound which can alter and/or maintain the solution pH within the desired range, and the selection l0 of such buffers can be made by referring to a standard text.
For instance, phosphates, carbonates, or bicarbo-nates, which buffer within the pH range of 6 to 12 are useful. Examples of suitable buffering agents 15 include sodium bicarbonate, sodium carbonate, sodium silicate, disodium hydrogen phosphate, sodium dihydrogen phosphate. The bleach solution may also contain a detergent agent where bleaching and laundering of the fabric is carried out simultaneously. The strength of 20 the detergent agent is commonly about 0.05% to 0.80 (wt.) in the wash water.
Although the activator, buffer and peroxygen com-pound can be employed individually in formulating the bleach solutions of the invention, it is generally more 25 convenient to prepare a dry blend of these components and the resulting composition added to water to produce the bleach solution. A soap or organic detergent can be incorporated into the composition to give a solution having both washing and bleaching properties. Organic 30 detergents suitable for use in accordance with the present invention encompass a relatively wide range of materials and may be of the anionic, non-ionic, cationic or amphoteric types.
The anionic surface active agents include ~hose 35 surface active or detergent compounds which contain an organic hydrophobic group and an anionic solubilizing group. Typical examples of anionic solubilizing groups ~ 12 -are sulfonate, sulfate, carboxylate, phosphonate and phosphate. Examples of suitable anionic detergents which fall within the scope of the invention include the soaps, such as the water-soluble salts of higher fatty acids or 5 rosin acids, such as may be derived from fats, oils, and waxes of animal, vegetable or marine oriyin, for example/
the sodium soaps of tallow, grease, coconut oil, tall oil and mixtures thereof and the sulfated and sulfonated synthetic detergents, particularly those having about 8 10 to 26, and preferably about 12 to 22, carbon atoms to the molecule.
As examples of suitable synthetic anionic detergents the higher alkyl mononuclear aromatic sulfonates are preferred particularly the LAS type such as the higher 15 alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the alkyl group, for example, the sodium salts such as decyl, undecyl, dodecyl (lauryl), tridecyl, tetradecyl, pentadecyl, or hexadecyl benzene sulfonate and the higher alkyl toluene, xylene and phenol sulfo-20 nates; alkyl naphthalene sulfonate, ammonium diamylnaphthalene su~fonate, and sodium dinonyl naphthalene sulfonate.
Other anionic detergents are the olefin sulfonates including long chain alkene sulfonates, long chain 25 hydroxy-alkane sulfonates or mixtures of alkenesulfonates and hydroxyalkanesulfonates. These olefin sulfonate detergents may be prepared, in known manner, by the reaction of SO3 with long chain olefins (of 8~25 pref-erably 12-21 carbon atoms) of the formula RCH-CHR , where 30 R is alkyl and R1 is alkyl or hydrogen, to produce a mix-ture of sultones and alkenesulfonic acids, which mixture is then treated to convert the sultones to sulfonates.
Examples of other sulfate or sulfonate detergents are paraffin sulfonates, such as the reaction products of 3S alpha olefins and bisulfites (for example, sodium bi-sulfite), primary paraffin sulfonates of about 10-20, preferably about 15-20 carbon atoms; sulfates of higher alcohols; salts of ~-sul~ofatt~ esters (for example, o~
about 10 to 20 carbon atoms, such as methyl,~-sulfomyri-state or ~-sulfotallowate).
Examples of sulfates of higher alcohols are sodium 5 lauryl sulfate, sodium tallow alcohol sulfate; Turkey ~ed Oil or other sulfated oils, or sulfates of mono- or diglycerides of fatty acids (for example, stearic ~ono-glyceride monosul~ate), alkyl poly(ethenoxy; ether sulfa~es such as the sulfates of the condensation pro-10 ducts of ethylene oxide and lauryl alcohol (usuallyhaving 1 to 5 ethenoxy groups per molecule); lauryl or other higher alkyl glyceryl ether sulfonates; aromatic poly(ethenoxy) ether sulfates such as the sulfates of the condensation products of ethylene oxide and nonyl phenol ~5 (usually having 1 to 20 oxyethylene groups per molecule, preferably 2-12).
The suitable anionic detergents include also the acyl sarcosinates (for example, sodium lauroylsarcos-inate) the acyl ester (for example, oleic acid ester) of 20 isethionates, and the acyl N-methyl taurides (for ex-ample, potassium N-methyl lauroyl or oleyl tauride).
Other highly preferred water soluble anionic deter-gent compounds are the ammonium and substituted ammonium (such as mono-, di- and triethanolamine), alkali metal 25 (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of the higher alkyl sulfates, and the higher fatty acid monoglyceride sul-fates. The particular salt will be suitably selected de-pending upon the particular formulation and the propor-~o tions therein.
Nonionic surface active agents include those surfaceactive or detergent compounds which contain an organic hydrophobic group and a hydrophilic group which is a re-action product of a solubilizing group such as carboxy-35 late, hydroxyl, amido or amino with ethylene oxide orwith the polyhydration product thèreof, polyethylel~e glycol.

As examples of nonionic surface active agents which may be used there may be noted the condensation products of alkyl phenols with ethylene oxide, for example, the reaction product of octyl phenol with about 6 to 30 ethylene oxide units; condensation products of alkyl thiophenols with 10 to 15 ethylene oxide units;
condensation products of higher fatty alcohols such as tridecyl alcohol with ethylene oxide; ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitol monolaurate, sorbitol mono-oleate and mannitol monopalmitate, and the conden-sation products of polypropylene glycol with ethylene oxide.
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.
As examples of suitable synthetic cationic deter-gents there may be noted the diamines such as those ofthe type RNHC2H4NH2 wherein R is an alkyl group of about 12 to 22 carbon atoms, such as N 2-aminoethyl stearyl amine and N-2 aminoethyl myristyl amine; amide-linked amines such as those of the type R CONHC2H4NH2 wherein R is an alkyl group of about 9 to 20 carbon atoms, such as N-2-amino ethyl stearyl amide and N-amino ethyl myristyl amide; quaternary ammonium compounds wherein typically one of the groups linked to the nitrogen atom are alkyl groups which contain 1 to 3 carbon atoms, including such 1 to 3 carbon alkyl groups bearing inert substituents, such as phenyl groups, and there is present an anion such as halide, acetate, methosulfate, and the like. Typical quaternary ammonium detergents are ethyl-dimethyl-stearyl ammonium chloride, benzyl-dimethyl-stearyl ammonium chloride, benzyl-diethyl stearyl am-monium chloride, trimethyl .stearyl ammonium chloride, trimethyl~ce~yl ammonium bromide, dimethylethyl dilauryl 15 ~
ammonium chloride~ dimethylpropyl-myristyl ammonium chloride, and the corresponding methosulfates and ace-tates.
Examples of suitable amphoteric detergents are those containing both an anionic and a cationic group and a hydrophobic organic group, which is advantageously a higher aliphatic radical, for example, of 10-20 carbon atoms. Among these are the N-long chain alkyl aminocar-boxylic acids, for example, of the formula R - N - R' - COOH;
the N-long chain alkyl iminodicarboxylic acids (for example, of the formula RN(R'COOHj2) and the N-long chain alkyl betaines, for example, of the formula R - N R' - COOH

where R is a long chain alkyl group, for example, of about 10-2Q carbons, R' is a divalent radical joining the 20 amino and carboxyl portions of an amino acid (for ex-ample, an alkylene radical of 1-4 carbon atoms), H is hydrogen or a salt-forming metal, R2 is a hydrogen or another monovalent substituent (for example, methyl or other lower alkyl), and R3 and R4 are monovalent sub-25 stituents joined to the nitrogen by carbon-to-nitrogen bonds (for example, methyl or other lower alkyl sub-stituents). Examples of specific amphoteric detergents are N-alkyl-heta-aminopropionic acid; N-alkyl-beta~imino-dipropionic acid, and N-alkyl, N,N-dimethyl glycine; the 30 alkyl group may be, for example, that derived from coco fatty alcohol~ lauryl alcohol, myristyl alcohol (or a lauryl-myristyl mixture), hydrogenated tallow alcohol, cetyl, stearyl, or blends of such alcohols. The substi-tuted aminopropionic and iminodipropionic acids are often 35 supplied in the sodium or other salt forms, which may likewise be used in the practice oE this invention.
Examples of other amphoteric detergents are the fatty imidazolines such as those made by reacting a long chain fatty acid (for example, of 10 to 20 carbon atoms) with diethylene triamine and monohalocarboxylic acids having 2 to 6 carbon atoms, for example, 1-coco-5-hydroxyethyl-5-carboxymethylimidazoline; betaines containing a sulfonicgroup instead of the carboxylic group; betaines in which the long chain substituent is joined to the carboxylic group without an intervening nitrogen atom, for example, inner salts of 2-trimethylamino fatty acids such as 2-trimethylaminolauric acid, and compounds of any of the previously mentioned types but in which the nitrogen atom is replaced by phosphorus.
The instant compositions optionally contain a detergency builder of the type commonly added to deter-gent formulations. Useful builders herein include any ofthe conventional inorganic and organic water-soluble builder salts. Inorganic detergency builders useful herein include, for example, water-soluble salts of phosphates, pyrophosphates, orthophosphates, polyphos-phates, silicates, carbonates, zeolites, including natural and synthetic and the like. Organic builders include various water-soluble phosphonates, polyphos-phonates, polyhydroxysulfonates, polyacetates, car-boxylates, polycarboxylatesl succinates, and the like.
Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, phos-phates, and hexametaphosphates. The organic polyphos-phates specifically include, for example, the sodium and potassium salts of ethane 1-hydroxy-1,1-diphosphonic acid and the sodium and potassium salts of ethane-1,1,2-tri-phosphonic acid. Examples of these and other phosphorus builder compounds are disclosed in U.S~ Patent ~os.

3,159,581, 3,213,030, 3,422,021, 3,422,137, 3,400,176 and 3,400,148. Sodium tripolyphosphate is an especially preferred, water-soluble inorganic builder herein.
Non-phosphorus containing sequestrants can also be selected for use herein as detergency builder3.

Specific examples of non-phosphorus, inorganic builder ingredients include water-soluble inorganic ~arbonate, bicarbonate, and silicate salts. The alkali metal, for example, sodium and potassium, carbonates, bicarbonates, and silicates are particularly useful herein.
Water-soluble, organic builders are also useful herein. For example, the alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, poly-l0 carboxylates and polyhydroxysulfonates are useful buil-ders in the present compositions and processes. Specific examples of the polyacetate and polycarboxylate builder salts include sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylenediaminetetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic (that is, penta- and tetra-) acids, carboxymethoxysuccinic acid and citric acid.
Highly preferred non-phosphorus builder materials (both organic and inorganic) herein include sodium carbo-20 nate, sodium bicarbonate, sodium silicate, sodium citrate,sodium oxydisuccinate, sodium mellitate, sodium nitrilo-triacetate, and sodium ethylenediaminetetraacetate, and mixtures thereof.
Other preferred organic builders herein are the 25 polycarboxylate builders set forth in U~S. Patent No.
3,308,067. Examples of such materials include the water-soluble salts of homo- and copolymers of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, aconitic acid, citraconic 30 aci~ and methylenemalonic acid.
The builders aforesaid, particularly the inorganic types, can function as buffers to provide the requisite alkalinity for the bleaching solution. Where the builder does not exhibit such buffer activity~ an alkaline re-acting salt can be incorporated in the formulation.
The dry blend compositions of the invention containabout 0.1 to 50% (wt.), prefera~ly 0.5 to 20% (~t.) of the herein sulf~nic anhydride activator. It will be appreciated that ~he concentration of activator will depend on the concentration of the peroxygen bleach compound which is governed by the particular degree of bleaching desired. Higher or lower levels within the range will be selected to meet the requirement of the formulator. As to the peroxygen bleaching agent, this is present to the extent of about 1 to 75% (wt.) of the composition, depending on the degree of bleaching activi-lQ ty desired. Generally speaking, optimal bleaching isobtained when the compositions are formulated with a peroxygen/sulfonic anhydride mole ratio in the range of from about 20:1 to 1:3, preferably about 10:1 to about 1:1. The composition will contain a buffering agent in ~S sufficient ~uantity to maintain a pH of about 6 to 12 when the composition is dissolved in water. The buf-fering agent can constitute from about 1% to about 95%
(wt.) of the dry blended composition.
The herein activated bleach compositions can be provided for use in combination with a detergent agent or as a fully-formulated built detergent. Such compo-sitions will comprise from about 5 to 50% of the acti vated bleach system, from about 5 to 50% (wt.) of the detergent agent and optionally from about 1 to 60% ~wt.) of a detergency builder which can also function as a buffer to provide the requisite pH range when the compo-- sition is added to water.
The compositions herein can include detergent adjunct materials and carriers commonly found in laun-dering and cleaning compositions. For example, variousperfumes, optical brighteners, fillers, anti-caking agents, fabric softeners, and the like can be present to provide the usual benefits occasioned by the use of such materials in detergent compositions. Enzymes, especially the thermally stable proteolytic and lipolytic enzymes used in laundry detergents, also can be dry-mixed in the compositions herein.

The solid peroxygen bleaching compositions herein are prepared by simply admixing the ingredients. When preparing mixed detergent/bleaches, the peroxygen and activator can be mixed either directly with the deter-gent compound, builder, and the like, or the peroxygenand activator can be separately or collectively coated with a water-soluble coating material to prevent pre-mature activation of the bleaching agent. The coating process is conducted according to known procedures in the art utilizing known coating materials. Suitable coating materials include compounds such as magnesium sulfate hydrate, polyvinyl alcohol, or the like.
The following examples are illustrative of the com-pounds of the invention:
Example 1 p-Toluenesulfonic Anhydride This specimen of p-toluenesulfonic anhydride was prepared by the method of Christensen, Acta Chem. Scand.
15, 1507 (1961) by reacting 93.6 g t1.7 mole) of sulfur trioxide with 49.7 g (0.54 mole) of toluene in 250 ml of nitromethane at 0C. The precipitated solids were recovered by filtration, washed sequentially with cold nitromethane, anhydrous ether and pentane and dried under vacuum; yield 29.8 g (33% yield) of product with mp 25 119-12704-C (lit. 129.5-131.5-C Field~ J. Am. Chem. Soc., 74, 394 (1952)~ Analysis of a similarly prepared ma-terial with mp 119.0-125-C gave the following:
C/ 51.57; H, 4.6~; S, 19.45. Theory for Cl4H14O5S2:
C, 51.54; H, 4.33; S, 19.62.
Example 2 Benzenesulfonic Anhydride A mixture of 46.8 g (0.585 mole) of sulfur trioxide and 21.1 g (0.27 mole) of benzene was dissolved in 125 ml of nitromethane. After one hour at O C, the nitromethane 35 was removed by vacuum distillation at 30-45-C/2 mm. The residue was taken up in 200 ml of dichloromethane and then stirred vigorously with ice water for 0.5 hour. The or-.

ganic phase was separated, washed with cold 5% sodium car-bonate solution and dried over anhydrous sodium sulfate.
After removal of solvent on a rotary evaporator, there re-mained 19O6 g of crude product which was dissolved in a 10:1 (volume) ether/benzene mixture at room temperature and the solution cooled in an ice bath to promote crystal-lization. The melting point of the purified material was 76.5-90 C (lit. 88-91C) with softening at about 75C~
Example 3 2,4,6-Trimethylbenzenesulfonic Anhydride Following the procedures of the previous examples, 2,4,6-trimethylbenzenesulfonic anhydride was prepared from 46~8 g (0.59 mole) of sulfur trioxide and 32.5 g (0.27 mole) of 1,3,5-trimethylbenzene (mesitylene) in 156 ml of nitromethane. Reaction time and temperature were one hour and O C, respectively. The precipitated material was recovered and washed as described in Example 1, giving 36.8 g (71% crude yield) of 2,4/6-trimethylben-zenesulfonic anhydride with mp 194.5-198-C. From NMR
20 data and elemental analysis, it was determined that the product contained approximately 28% mesitylene disulfonic acid.
Example 4 Dichlorobenzenesulfonic Anhydride Dichlorobenzenesulfonic anhydride was prepared from o-dichlorobenzene and sulfur trioxide following the pro-cedure of Example 3. There was obtained 38.2 g (65%
yield) of dichlorobenzenesulfonic anhydride having a melting range of 104-115.5 C; NMR and elemental analysis indicated the product contained about 50% free acid.
Example 5 Dimethylbenzenesulfonic Anhydride Dimethylbenzenesulfonic anhydride was prepared from o-xylene and sulfur trioxide, as described in the pre-35 vious example. There was obtained 18.6 g (39% yield)of dimethylbenzenesulfonic anhydride melting at 115.0-130.5-C. The NMR spectral data indicated that a small quantity of free acid was present in this sample.
Example 6 p-Chlorobenzenesulfonic ~nhydride p-Chlorobenzenesulfonic anhydride was prepared, as 5 described in the previous examplep by reacting 9~4 g (0.12 mole) of sulfur trioxide with 6.0 g (0.054 mole) of chlorobenzene. There was obtained 5.7 g (57.2%
yield) of product with mp 140.0-147.3C (lit. 130-141C
Christensen, Acta Chem. Scand. 15, 1507 (1961); lit. mp 0 for p-chlorobenzenesulfonic acid =50.5-C, Dictionary of Cpds., Vol. 2, 4th Edition, Oxford Univ. Press, N.Y., p. 601~.
Anal: Calc d for C12H8O5S2Cl2: C, Found: C, 39~20; H, 2.50 S, 17.61.
Example 7 p-Iodobenzenesulfonic Anhydride p-Iodobenzenesulfonic anhydride was prepared as described in the previous example from 46.8 g (0.59 mole) of sulfur trioxide and 55.1 ~ (0.27 mole) of 20 iodobenzene in 156 ml of nitromethane. There was ob-tained 65.8 g (85.7% yield) of product with mp 207-214-C
(lit. 220-221-C, Christensen, Acta Chem. Scand. 15, 1507, 1961).
Anal: Calc d for C12H8O5S2I2 C, 26-19;
25 Found: C, 26.02; E~, 1.49; S, 11.75.
Example 8 p-Methoxybenzenesulfonic Anhydride p-Methoxybenzenesulfonic anhydride was prepared by adding dropwise, 4.2 g (0.052 mole) of sulfur trioxide, 30 dissolved in 35 ml of nitromethane to a stirred and chil~
led solution of 2.7 g (0.025 mole) of anisole (phenyl methyl ether) in 25 ml of nitromethane. The novel product was recovered by filtration, washed and dried, as described in the previous examples, giving 1.9 g (42%
35 yield) of product melting at 126.5-131.0'C. The proton NMR and elemental analytical data indicated that some free acid, probably anisole sulfonic acid, was present in , the product.
Anal: Calc'd for C14H14O7S~: C, 46.92; H, 3.94; S, 17-89-Found: C, 45.59; H, 4.03; S, 17.70 (Theory for anisole sulfonic acid: S, 17.04).
Example 9 CI~3S020S02C6H5 1.76 g (0,01 mole) of benzenesulfonyl chloride and 2.03 y (0.01 mole) of silver methanesulfonate were com-bined in 15 ml of dichloromethane. The mixture was stir-10 red for three days and filtered to remove silver chloride.The filtrate was evaporated to dryness, giving 1.45 g of a viscous liquid product.
Example 10 CH3S~2S2 ~ C1 This sulfonic anhydride was prepared in the same man-ner as the previous example by combining 8.4 g (0.04 mole) of 4~chlorobenzenesulfonyl chloride and 8.12 g (0.04 mole) of silver methanesulfonate in 50 ml of dichloromethaneO
25 The solid product weighed 5.3 g; 49% yield.
Example 11 CH3so2oso;~cH3 Following the procedure of the previous examples, this sulfonic anhydride was prepared by combining 7.62 g (0.04 mole) of p-toluenesulfonyl chloride with 8.12 g (0.04 mole) of silver methanesulfonate in 50 ml of dichloromethane. There was ob~ained 5.2 g (52% yield) of product.
. .

Example 12 C~3SO~OSO2-~CH3 Following the procedure of the previous examples, this sulfonic anhydride was prepared by combining 4.4 g (0.02 mole) of mesitylenesulfonyl chloride (~,4,6-tri-methylbenzenesulfonyl chloride) with 4.06 g (0.02 mole)of silver methanesulfonate in 25 ml of dichloromethane.
After reacting overnight at room temperature, the mixture was filtered. Evaporation of the ~iltrate gave 3.99 g :~. (72% yield) of product.
Example 13 Cyclohexanesulfonic Anhydride To a stirred solution of 35 ml of phosphorus tri-chloride in 300 ml of cyclohexane was bubbled (room temp.) 167 ml/minute of $ulfur dioxide and 83 ml/minO of oxygen. After several hours, an additional 25 ml portion of phosphorus trichloride was added, followed by anoth~r portion. The solution was evaporated to a total volume of 100 ml in a rotary evaporator; on chilling, yielded 14.~ g of white crystals with mp 90-93 C was deposited.
Crystallization from cyclohexane gave 12.4 g of solid with mp 97-100-C (lit 106-107~C~. The procedure of this Example was patterned after that disclosed in Ann. Vol.
57~, pg. 79, ~1952).
Anal Calc d for C12H22S25 C~ 46-73; ~ ;
Found: C, 46.70; H, 7.24; S, 20.29.
This example illustrates another synthesis route for preparing sulfonic anhydrides~ The procedure is prac-tical only ~or symmetrical membersO
Evaluation of Compounds as Bîeach Activators Compounds of the invention were evaluated for bleach activating efficacy by determining the increase in ~- percent tea stain removal ~%TSR) achieved by use of both .
`" ; ' .
. -~ ``' " ~"`
' 5Q~

the peroxygen source and activator compared with that obtained by use of the peroxygen source alone. Both tests were performed under otherwise identical low temperature laundering conditions. The increase in %TSR is called ~%TSR. The evaluation was carried out in the presence of a detergent formulation and sodium perborate tetrahydrate as the source of peroxygen com-pound, ;;jTea-stained cotton and 65% dacron/35% cotton swatches, 12.7 x 12.7 cm~ (5" x 5"), used in these tests were prepared as follows: For each 50 swat~hes, 2000 ml ~f tap water was heated to boiling in a four-liter beaker. Reflectance readings were made on each swatch, using a Hunter Model D-40 Reflectometer before staining.
Two family size tea bags were added to each beaker and boiling was continued for five minutes. The tea bags were ;then removed and 50 fabric swatches were added to each beaker. The dacron/cotton and 100~ cotton swatches were boiled in the tea solution for seven and five minutes respectively, after which the entire content of each beaker was transferred to a centrifuge and rotated for about 0.5 minutes.
The swatches were then dried or thirty minutes in a standard household laundry drier. One hundred dry swatches were rinsed four times by agitating manually in 2000 ml portions of cold tap water. The swatches were dried in the household drier for approximately 40 min-utes; they were allowed to age f~r at least three days before use. Reflectance readings ~or each swatch were taken prior to bleaching tests, using a Hunter Model D-40 Reflectometer.
Three stained cotton and polyester/cotton swatches were added to each of several stainless steel Terg-O-To-meter vessels containing 1000 ml of 0.15~ detergent solution, maintained at a constant temperature of 40-C
(105 F). The Terg-O-Tometer is a test washing device manufactured by the U.S. Testing Company. The detergent ~ : ~ . . .: . . .
; . ~. : :. .

-solution was prepared from a detergent formulation having the following composition ~by weight):
25.0% - Sodium tripolyphosphate 7.5% - Sodium dodecylbenzenesulfonate (anionic surfactant)

4.0% - Alcohol ether sulfate (o~tained from 1 mole of C16-C18 alcohol with 1 mole ethylene oxide ~anionic surfactant) 6.5% Alcohol (C16 C18) sulfate ( lQ factant) 1.3% - Polyethylene glycol of about 6000 molecular wt.
35.4% - Sodium sulfate 11.0% - Sodium silicate 8.0% - Moisture 0.8% - Optical brightener 0.5~ - Carboxymethylcellulose Measured quantities of sodium perborate tetrahydrate were added to each vessel to provide the desired quantity of active oxygen (A.O.) followed by an amount of activator compound to give the bleaching A.O. levels. In each test run, the activator was excluded from at least one Terg-O-Tometer vessel. The pH of each solution was adjusted to about 10.0 with 5% sodium hydroxide solution. The Terg-O-Tometer was operated at 100 cycles per minute for 15 or 30 minutes at the desired temperature. The swatches were then removed, rinsed under cold tap water and dried in a household clothing drier. Reflectance readings were taken on each swatch and percent tea stain removal (%TSR) was calculated as follows~
(Reflectance (Reflectance %TSR _ After ~leaching) - Before Bleaching) X 1 0 0 (Reflectance - (Reflectance Before Staining) Before Bleaching) The increase of %TSR, termed ~%TSR, was calculated by subtracting the average ~TSR in runs where the perborate was present alone, from the average %TSR obtained in runs .
.:
.

where both the act ivator and the perborate were present.
The test results ~re given in Tables I and II. As the ~TSR values clearly demonstrate, the activator compounds of the invention markedly improve the percentage of stain

5 removal compared to the peroxygen bleach compound alone.

TABLE I
Sodium Perbo~ate Tetrahydrate Example 1 To Give ~.O, Number ComE~und ~es~ed ppm 1p-Toluenesulfonic Anhydride 60 1 " " 60 1 " " 60 1 " " 60 1 " " 60 1 " " 60 1 " " 30 1 " " 30 1 ~ 11 30 1 11 " 30 2 Benzenesulfonic Anhydride 60 2 11 " 60 2 " "2 60 3 2,4,6-Trimethylbenzene-sulfonic Anhydride4 30 4 Dichlorobenzenesulfonic Anhydride 60 4-Chlorobenzenesulfonic Anhydride5 60

6 4-Iodobenzenesulfonic 60 . ~ ' 3~

TABLE I - CONTINUED
Mole Ratio f ~TSR
Example Perborate/ On bn Number Activator Cotton Dacron/Cotton 1 2 6~ 49 1 ~ 53 43 1 3.8 23 9 2 45 3~

f~

TABLE I - CONTINUED
~%TSR
Exarnple On On Final Number Cotton Dacron/Cotton pH
1 27 22 10.32 1 36 38 10.43 1 21 15 10,05 1 40 41 10.34 1 34 29 10.12 1 31 23 10.01 1 20 22 10.29 1 0 -2 g.73 1 -4 -3 9.50 1 1 1 9.92 1 4 0 9.75 2 33 31 10.15 2 ~3 25 --~ 49 33 10.19 2 46 46 10.13 4 15 11 9.93 ~6 20 --6 4 7 10.01 All tests were performed at 40C (105'F~ for 30 minutes.
Bleaching carried out at 21.1C (70-F).
Bleaching carried out at 30.9 C (37.5 F).
4Activator was blended with 20% (w/w) sodium phthalate to aid dissolutlon.
5Activator was stored in air at 21.1 C (70 F)/50% relative humidity for two weeks, then tested.

TAsLE I I :2 BLEACEI TEST1 RESULTS WITH SULFONIC ANHYDRIDES: RlS020S02R
Active Oxyg e n Compound R1 R2 , _ _ 1~ CH3 CH3 60 " 60 " 60 " 60 " 1 5 4 CH3 p-C6H4CH3- 60 " 60 " 60 54 CH3 2,4,6-(CH3)3- 604 " ,. ~U

7 cyclo cyclo 60 C6H~ 1 C6Hl ~

TABLE II - (CONTINUE~) Mole Ratio of Peroxygen Com- ~TSR
Com~ound pound/Activator_otton Blend 13 1.4 65 40 2.4 52 25 2.4 67 41 3~5 66 38 2.7 47 15 3 0.86 75 69 0.86 80 71 1.9 46 23 1.9 30 13 7 2 ~0 29 TABLE I I - ( CONTINUED ) ~%TSR
CompoundCotton Blend ~7 32 46 2~

5~ 38 40 1) All tests performed at 38-40~C (100-105-F) for thirty minutes.
2) Sodium perborate tetrahydrate used as active oxygen source, unless otherwise specified.
3) Purchased from Aldrich Chemical Co.
4) Sodium carbonate peroxide as active oygen source.
5) Purchased from Pfaltz & Bauer, Flushing, N.Y.

Claims (13)

Claims:

1. A process for the low temperature bleaching of stained and/or soiled fabrics characterized by treating them with an aqueous peroxygen bleaching solution having a pH of 6 to 12 and containing as a peroxygen activator therefor, an effective amount of a sulfonic anhydride having the formula:

wherein each of R1 and R2, which may be alike or dif-ferent, is an aliphatic radical selected from the class consisting of an alkyl radical of 1 to 18 carbon atoms; a cycloalkyl radical of 3 to 7 carbon atoms and an aromatic ring system selected from the class consisting of a phenyl group, taken together are an o-phenylene group, a naphthyl group, taken together are an o-naphthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the class consisting of nitrogen, oxygen and sulfur, said aromatic groups optionally bearing l to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine.

2. The process according to claim 1 characterized in that the mole ratio of peroxygen to activator is from 20:1 to 1:3.

3. The process according to claim 2 characterized in that the peroxygen is sodium perborate tetrahydrate.

4. The process according to claim 2 characterized in that the quantity of peroxygen is sufficient to provide from 2 parts per million (ppm) to 2000 ppm of active oxygen.

5. The process according to claim 1 characterized in that the bleach solution contains a detergent agent.

6. The process according to claim 1 characterized in that the pH of the bleach solution is maintained by means of a buffering agent.

7. The process according to claim 1 characterized in that the activator is selected from the class consisting of p-toluene-sulfonic anhydride, benzenesulfonic an-hydride, 2,4,6-trimethylbenzenesulfonic anhydride, di-chlorobenzenesulfonic anhydride, dimethylbenzenesulfonic anhydride, p-chlorobenzenesulfonic anhydride, p-iodo-benzenesulfonic anhydride, and p-methoxybenzenesulfonic anhydride.

8. A bleaching composition consisting essentially of a peroxygen bleaching compound and as a peroxygen acti-vator, an aromatic sulfonic anhydride of the formula:

wherein each of R1 and R2, which may be alike or dif-ferent, is an aliphatic radical selected from the class consisting of an alkyl radical of 1 to 18 carbon atoms; a cycloalkyl radical of 3 to 7 carbon atoms and an aro-matic ring system selected from the class consisting of a phenyl group, taken together are an o-phenylene group, a naphthyl group, taken together are an o-naphthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the class consisting of nitrogen, oxygen and sulfur, said aromatic groups optionally bearing 1 to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine.

9. The composition according to claim 8 charac-terized in that the peroxygen compound is sodium per-borate tetrahydrate.

10. A detergent composition consisting essentially of a detergent agent and the composition defined in claim 8.

11. A bleaching composition consisting essentially of a peroxygen bleaching compound, an aromatic sulfonic anhydride activator of the formula:

wherein each of R1 and R2, which may be alike or dif-ferent, is an aliphatic radical selected from the class consisting of an alkyl radical of 1 to 18 carbon atoms; a cycloalkyl radical of 3 to 7 carbon atoms and an aro-matic ring system selected from the class consisting of a phenyl group, taken together are an o-phenylene group, a naphthyl group, taken together are an o-naphthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the class consisting of nitrogen, oxygen and sulfur, said aromatic groups optionally bearing 1 to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine, and sufficient buffering agent to maintain a pH of 6 to 12 when the bleaching composition is dissolved in water.

12. The bleaching composition of claim 11 charac-terized in that the mole ratio of peroxygen to activator is from 20:1 to 1:3.

13. A detergent composition consisting essentially of (a) from 5% to 50% by weight of the bleaching composition of claim 11; (b) from 5% to 50% by weight of a detergent agent; and (c) from 1% to 60% by weight of a detergency builder.