Liquid hydrogen peroxide bleach containing a peracid activator

DESCRIPTION

This invention relates to peroxidic bleaching compositions and in particular to formulated stable liquid for bleaching clothes, which contain activators in combination with liquid hydrogen peroxide.

Clothing bleaches can be classified by the chemical type: chlorinated bleaches and bleaches with active oxygen, that is, peroxygenated, and by the fossil form: solid and liquid.

Peroxygenated bleaches can use liquid hydrogen peroxide, solid orgabonic peroxyacids, or solid inorganic peroxisals and can have numerous advantages. Peroxygenated bleaches are safe for fabric colors and to some extent do not make white fabrics yellow. They are not destructive of the fossil resistance of the tissue and communicate a good touch and absorbency to it.

These peroxygen bleaching agents have been used to remove stains and dirtiness in two different types of washing conditions. In the first type, high washing temperatures are used, especially above 85 C and currently around 100 C, as frequently occurs in commercial laundries and with some European domestic washing machines. At these high temperatures, a peroxygenated material such as hydrogen peroxide or percarbonate or sodium perborate can be added to the wash mixture and effectively bleached. Low temperatures are usually used in domestic washing machines in the United States. For this application, hydrogen peroxide in combination with activators has been described and a number of materials have been proposed as activators for peroxygen bleach that increase the bleaching action at low to moderate temperatures.

The selection of peroxygenated-activating bleach combinations must respond to a complex equilibrium of two contradictory characteristics. The combination must be stable in storage and experience a loss of no more than 10-20% of its activity during a period of 90 days at 15-30 ^ C. On the other hand, the combination must be so reactive that when added to a cold water wash solution (1030 C), it reacts substantially in 1-2 minutes so that it is effective for most of the 10-12 minutes that The washing cycle of an automated washing machine lasts. Therefore, a combination of peroxygenated-activating compound must have a reaction rate in the washing machine 10,000 to 100,000 times greater than the tolerable decomposition rate during storage. With the solid or dry powder compositions, storage stability can be achieved by mixing the solid persalt and the solid activator in the form of dry powders and as long as they are kept dry during storage, no reaction or loss of significant activity occurred until The mixture is poured into the washing machine. In very humid environments, such as those that reign frequently in the washrooms, dry products can get wet and lose activity. When liquid hydrogen peroxide is used as a source of peroxide, it is not possible to obtain a dry powder product.

There have also been several proposals for liquid peroxidic bleaches. However, none of them has described how to incorporate activators and achieve a stable storage product.

Barrett, Jr., in US Patent 3,970,575, discloses a bleaching product based on hydrogen peroxide that was stabilized against acids but that is not seen to contain any activator.

Jones, in US Patent 3,956,159, describes a liquid bleach based on an orgaonic peroxyacid and its salts in an anhydrous ternary orgaonic solvent.

Edwards et al., In US Patent No. 3,996,152, discloses a fluid product that employs a suspension of a water-insoluble solid peroxygenated compound, a thickener other than starch and an acidifier in a liquid vehicle such as water. In view of the requirement that the peroxygenated compound be insoluble in water, hydrogen peroxide would not be applicable to this system.

Bradley, in US Patent 4,017,412, describes the same type of system as Edwards et al., But uses a starch thickener.

Kandathill, in US Patent 4,238,192, describes a bleaching liquid based on hydrogen peroxide. It does not appear to contain any activating but contains acid to give a pH of 2.8 to 5.5 and a nitrogen compound (specifically, an amino acid) to communicate stability.

Lutz et al., In US Patent 4,130,501, describe a bleaching liquid of hydrogen peroxide to which a surfactant and a thickening agent have been added, again without specifically pointing out that the mixture contains any activating noon.

Therefore, references that target stable but peroxygenated liquid bleaches do not mention the need for the presence of any activator while references dealing with activating systems do not indicate how to select or use the activator so that it acts in a stable liquid bleach. in the long term based on hydrogen peroxide.

With this background and in view of the particular problems posed by a liquid bleach based on hydrogen peroxide and which must be stable in storage, on the one hand, but must contain activators to produce a good bleaching effect at low wash temperatures at moderate, the present invention has been completed.

European Patent Application EP-A0.092.932 describes a useful composition for bleaching and disinfecting, which contains hydrogen peroxide and an activator, characterized in that it is constituted by an acidic aqueous solution of hydrogen peroxide in which a dispersion has been dispersed. organic phase with an emulsifying amount of an emulsifier, whose organic phase contains a

016 840 enol-ester. This enol-ester is an activator.

According to this invention, the activator that is used is a solid particulate activator containing a base ionizable group.

This invention provides a liquid bleaching composition for washing clothes, which is active at a low temperature and stable in storage, which is constituted by an aqueous acidic medium with a pH of 2.0 to 6.0 and contains from 1% to 25% by weight of hydrogen peroxide and the dispersion of 0, 10 moles per mole of hydrogen peroxide of a peroxidized activator, peraceid precursor solid, which is insoluble in said acidic aqueous medium but which is soluble in alkaline wash water, whose activator responds to a form selected from:

<img file="ES2016840B3_D0001.tif" />

where

Xeshydrogen, lower alkyl, lower acyl or lower alkoxy, where "lower" means 1 to 4 carbon atoms; an aryl of about 6 carbon atoms or an chlorine, bromine or iodine atom;

GS is a solubilizing group selected from aromatic and aliphatic acids and thioaacids and their alkali metal and alkaline-metal salts, aromatic alcohols, aromatic thiols, aromatic anhydrides, maleimides and sulfonamides;

GS 'is a COOM or COSH group; where M is hydrogen or an alkali metal or alkaline earth metal ion;

mes1o2;

R¹ and R are independently selected from H and C „z H2n '+ i;

n 'is a number 1 to 20 and n is a whole number from 1 to 20.

In another aspect, this invention provides an improved method for bleaching dirt and stains from washed clothes, which consists in contacting the clothes with an aqueous wash solution at 10-75 ° C, with a pH of 7.0 or higher, to which an effective bleaching amount of a liquid bleach according to this invention has been added.

In this specification and in the claims, several terms will be used which are defined below:

A solid is defined as "insoluble" in the bleached liquid liquid when its maximum solubility is less than 1.0% by weight in the liquid and preferably when its maximum solubility is less than 0.5% by weight in the liquid.

According to this invention, the activator must be at least 10 times more soluble in the washing liquid than in the bleached concentrated liquid. Preferably, the activator is at least 50 times more soluble in the washing liquid than in the concentrated liquid bleach and even better is at least 100 times more soluble.

The bleaching compositions of this invention are constituted by liquid hydrogen peroxide and an aqueous aqueous medium with a particulate activated solid dispersed or suspended in it.

The concentration of hydrogen peroxide in the composition is controlled between 1% and 25% by weight, with H2O2 concentrations of 2 to 20% being preferred and still better than 3 to 10%.

The pH of the composition remains weakly acidic, that is, between 2.0 and immediately below 6.0 and preferably between 2.0 and 5.0. Low pH values, although technically usable, present risks of corrosivity that may be unacceptable in a household wash product of great diffusion. These pH values ​​of 2.0 to 6.0 can be achieved by the addition of appropriate acidifiers such as organogenic or inorganic aids, acidic salts that buffer the pH at an acidic value or the activator itself that can release hydronium ions and produce a pH airy Examples of suitable acidifiers are inorganic acids such as sulfuric, sulphurous, hydrochloric and phosphatic; organogenic acids such as acetic, alkylsulfogenic and tartaric, and air salts such as seodic hydrogen phosphate, potassium hydrogen phosphate and the like. If desired, a combination of acidifiers can be used. Although it is not known with certainty, it seems that the aerial pH used in the composition exerts two synergistic functions: on the one hand, it stabilizes the peroxide by displacing the equilibrium of the perhydrolysis reaction in the direction of the

016 840 non-ionized RCOOH acid form and in the opposite direction to the active OOH form and on the other hand, remove the destabilizing activator from the solution by making it insoluble.

The activators used in the bleaching compositions of this invention can be characterized as "insoluble" at the storage pH values ​​and also as 10, 50 or 100 times more soluble at the pH values ​​used in the bleaching. The pH of the bleaching operation is 7 or more. The storage pH is less than 7. The activators that can exhibit this pH-dependent solubility are activators that contain weakly acidic groups such as free groups carboxylic acid, sulfonamido, thiocarboxylic acid, hydroxyls or aroamatic thiols, anhydrides and cacic amides, as solubilizers. At acidic pH, these groups are not ionized and contribute to insolubility. At basic pH, the groups become increasingly ionized and solubilize the activator. It seems that these groups are especially suitable as solubilizers in this situation. Sulfonate or phosphonate groups are not acceptable because they are too ionized and lead to excessive solubilization of the activator at acidic pH in which it is desired that no ionization occurs and insolubility occurs. Quaternary ammonium groups are not appropriate as they also tend to form ioan pairs with the anions present in the wash mixture. Therefore, the activators used herein can be classified as materials containing ionizable solubilizing groups that are practically non-ionized under storage conditions and subsequently ionized under the conditions of use and which do not contain any sulfonate, phosphonate or quaternary ammonium groups.

Therefore, the tactic activators that may be useful here due to their insolubility in storage and their solubility in use are those specified in the definition of the compositions according to this invention.

A preferred group of activators can be structurally described by the formula

R -C - O - R '- COOM II

Or where R is an alkyl group of 1 to 12 carbon atoms and R 'is an arylene group of 6 carbon atoms, optionally with a substituent X as described above, which will exert an electron accepting effect on the -CO cenI group

Or tral to promote substitution by perhydroxyl ions (OOH^-). M is hydrogen, an alkaline metal ion or an alkaline-metalic metal ian, usually K⁺ oNa⁺(If Metallic death, when the activator is placed in an acidic medium, the metal ion will immediately be substantially replaced by hydrogen.) This activator may experience the following reactions in an aqueous medium at pH 7 or more:

Solubilization

RCO-R'-COOM (s) + OH^- —&gt;

I

O -&gt; RCO-R'-COO^- + MOH I

OR

Activation

RCO-R'-COO^- + ^-OOH -&gt;

I

O -&gt; RC-OOH + ^-O-R'-COOI

OR

Preferred R groups contain 3 to 10 carbon atoms, and still better than 5-9 carbon atoms and the most preferred are C7 normal alkyls. R 'may preferably be selected from arylene groups of 6 to 10 carbon atoms, which optionally contain up to two alkyl substituents, totaling up to 8 carbon atoms. Phenylene is the most preferred R 'group in this activator class.

Taking into account the preferences we have defined, a more preferred group of formula activators can be defined

<img file="ES2016840B3_D0002.tif" />

Or where n is an integer from 2 to 8, especially from 4 to 8 m and preferably around 6 and M is hydrogen, Na⁺ okay⁺. The COOM group can be found in various positions within the aromatic ring, the position being preferred for the -O- link.

The activators described above can be produced by known methods. A generally applicable procedure for the training of activators

R -C - O - R '- COOM I

Or it consists in forming a formula anhydride first

RCOCR

II OO by condensation of two acid molecules

RC-OH

I

Or in the presence of an excess of acetic anhydride,

016 840 under conditions of dehydration and then reacting the roasted anhydride formed with a hydroxylated phosphorus acid

HO - R '- COOM generally in the presence of a strong acid. An alternative process takes place through the acid chlorides and is described here in the Preparations. The activators can be recovered in solids and are used as particulate solids in the bleaching products of this invention. They are generally ground or subdivided in some other way up to a size of 118.3 μm (mesh # 140) or less (preferably up to a size of 100 micrometers or less and even better up to a size of 50 micrometers or less) to facilitate its dispersion or suspension in the bleaching products.

The solid activator is added in proportions of 0.1 to 10.0 moles per mole of hydrogen peroxide. As the activator is more expensive than hydrogen peroxide, for economic reasons it is preferable not to use a large excess of activator so that ratios of 0.2 to 2 moles of activator per mole of hydrogen peroxide and especially 0 are preferred. , 3 to 1 mole of activator per mole of hydrogen peroxide.

The activated and stabilized bleaching and liquid compositions of this invention may contain other components such as fragrances, dyes, fluorescents, optical brighteners, cleaning agents and thickeners or suspending agents. Also, if desired, supplemental peroxodic stabilizers such as heavy metal chelating liquids, for example EDTA, can be added. When selecting these components, it is important not to choose materials that react with hydrogen peroxide and destabilize it during storage. It is also important to ensure that the product has an acidic pH, if necessary with acid additions if the other components produce a pH increase.

Fragrances and dyes can be chosen from materials known in this field, subject to the aforementioned conditions related to stability and pH.

Representative fluorescent optic brighteners include naphtholtriazole, stilbene and diestyrylbiphenyl, sold by the Ciba-Geigy Corporation under the Tinopal brands^(R) RBS and Tinopal^(R) CBS-X, respectively. Other useful brighteners are described in columns 3, 4 and 5 of US Pat. No.^° 3,393,153 and also in publication D-553A of the ASTM "List of Fluorescent Whitening Agents for the Soap and Detergent Industry" Among the representative surface active agents are conventional non-ionic, amphoteric and zwitterionic surfactant materials, already described in this field. Examples of surfactants suitable for use in these formulations can be found in the work of Kirk-Othmer, Encyclopedia of Chemical Technology, 3^to Edition, Volume 22, págs. 247287 (1983) and in McCutcheon's, Detergents and Emulsifiers, North American Edition (1983).

These two descriptions are incorporated herein by reference. A generally preferred group of surfactants are non-ionic surfactants as described in the pages. 360-377 of the work of Kirt-Othmer. Nonionic materials include alcohol ethoxylates, alkylphenol ethoxylates, carboxylic acid oresters, glycerol oresters, polyoxyethyl oenic oresters, anhydrosorbitol oresters, ethoxylated anhydrosorbitol oresters, fatty acid and carboxylic fatty acid oxytolates, , diethanolamine condensates, monoalkanolamine condensates, polyoxyethylene fatty acid amides, block copolymers of polyalkylene oxides, non-ionic poly (oxyethylene-co-oxypropylene) surfactants and the like. A wide range of these materials is on the market, including Shell Chemical Neonol, Union Carbide Tergitol, ICI Tween and Span and the like.

Representative suspending agents or thickeners include the surfactants just described, preferably sorbitan oesters (anhydrosorbitol oresters) and ethoxylated sorbitan oresters, especially with mixtures of these materials. "Span" materials^(R) and "Tween"^(R) ICI's are of this type and give good results as suspending agents. Other generally preferred suspending agents are polyoxyethylene / polyoxypropylene block copolymers, such as those sold by BASF-Wyandotte as "Pluronic" surfactants^(R) and polyacrylic acids marketed by BF Goodrich under the brand "Carbopol"^(R).

Representative thickening agents are water-soluble gums such as seaweed gums that include araobic gum, guar gum and the like - cellulose derivatives, clays and colloidal silica, provided that heavy metal contamination is eliminated.

The bleaching formulations of this invention are prepared simply by mixing the hydrogen peroxide with the activator and with any of the optional ingredients described above and diluting to the appropriate concentration.

As already noted, the activator is in a finely divided form. It can be added as such or, if desired, can be formed in situ. This may mean that starting from the activator in solution, for example at pH 10, in the absence of peroxide and then the pH is reduced to an acid value by the addition of an acid, thereby creating the conditions under which the activator is insoluble and precipitates This can lead to the formation of fine particles of activator in situ. Then the peroxide is added. Generally the product is packaged in bottles but can also be sold in other liquid-tight containers such as bags or the like.

The liquid bleaching compositions of this invention are used in accordance with conventional washing practice. They are added in adequate quantities to achieve the effective removal of stains and dirt. This is

016 840 achieves with adequate amounts to generate about 5 to 30 parts per million by weight of peracid in the final wash mixture. For a normal wash water volume of 68 liters, this means 6 to 34 grams of activator and 0.72 to 5 grams of hydrogen peroxide. In accordance with normal washing practice, the liquid bleaching agents of this invention can be used in combination with soaps and detergents, fabric softeners and other materials conventionally used in the washing processes.

The bleaching liquid can be added directly to the fabric to remove stains and the like or it can be added to the washing liquid. In any case, the washing should be initiated shortly after the addition of the bleach, that is, within a period of 1 hour or roast and preferably within about 15 minutes, in order not to damage the colors due to prolonged contact with the bleach concentrated as well as to reduce the loss of active oxygen due to decomposition in washing conditions.

Since the bleaches of this invention require a basal pH to achieve solubilization of the activator, they work best when used together with a detergent or wash aid or the like that provides a wash liquid with a dubiously alkaline pH. Thus, detergents and the like can be advantageously chosen from the dubly alkaline materials such as sodium carbonate, sodium silicate, STPP phosphate and the like.

This invention will also be described by the following preparations and examples that are included as illustrations and should not be considered as limiting the scope of this invention. Preparation 1

A round bottom flask with 4 mouths and 2 l capacity is provided with a vane stirrer and a refrigerant with a desiccant tube. To this flask is added 500 ml of tetrahydrofuran (THF), followed by 150 g (1.1 mol) of phidroxybenzoic acid. After a few minutes of stirring, all the solids have dissolved. To this solution, 180 ml (2.2 moles) of pyridine are added from a decant funnel followed by 19 ml (1.1 moles) of octanoolo chloride over half an hour. The white solid pyridine hydrochloride begins to precipitate from the solution as soon as the acid chloride is added. This suspension is stirred at room temperature for approximately 3 hours.

The solid is separated by filtration and the transparent filtrate is introduced into a rotary evaporator to remove the solvent, forming a suspension. To this suspension about 300 ml of hexane is added, the mixture is stirred for half an hour and filtered to give a white solid.

This white solid is dissolved in 11 distilled water and adjusted to pH 1.0 approximately with dilute hydrochloric acid; now a large amount of white solid precipitates from the solution. The solid is isolated by filtration and dried in a vacuum oven. The dried solid gives 184.5 g (yield

64%) of white solid with a melting point of 150-151.5 ^ C. An infrared spectrum of the material has a defined peak at 1768 cm^-1 for an aromatic oester and a peak at 1690 cm^-1 for an aromatic carboxylic acid. The spectrum of¹³CRMN (CDCl3, downstream of TMS) presents the acid carbonyl at 171.6 ppm, the carbonyl of the ester at 171.5, the aromatic carbon attached to the oxygen to

155.3, the aromatic carbon bonded to the carbonyl at 126.8, the aromatic carbons adjacent to the oester at 121.7, the aromatic carbons adjacent to the carbonyl at 131.9 and the aliphatic carbons in the range of 14.0 to 34, Four. No other line is present, except those of the desired compound, indicating that this solid is of high purity.

The product is insoluble in distilled water (pH 7) but soluble in alkaline water (pH 9.5, 10.5). Preparation 2

Following the methods indicated in Preparation 1 but replacing the noctanool chloride with n-nonanool chloride, the corresponding ester of the activating n-nonanoic acid is obtained.

Preparation 3

Following the methods indicated in Preparation 1 but replacing the noctanole chloride with n-heptanool chloride, the corresponding activating n-heptanoic acid oester is obtained.

Example 1

Two liquid bleaching agents are prepared according to this invention, with the following formulations:

<td></td><td>Formulated 1</td><td>Formulated 2</td>

<td>H2O2 (6%) P- (n-octanoyloxy) benzoic acid (solid activator</td><td> 87%</td><td> 67%</td>

<td>particulate) Arlacel^(R) 83 (ester</td><td> 13%</td><td> 13%</td>

<td>of anhydrosorbitol) Tween^(R) 40 (sorbitan and acid ester</td><td> 0%</td><td> 12%</td>

<td>ethoxylated palmitic)</td><td> 0%</td><td> 8%</td>

In Formula 1, the molar ratio of H2O2 to activator is 3: 1. In Formula 2, the molar ratio is 2.4: 1. Both Formulas 1 and 2 contain a three-fold excess of hydrogen peroxide and enough benzoic acid oester to theoretically generate 14 ppm of peroxide (as active oxygen) in 68 l of washing liquid when half a beaker is used. The pH of each of the formulations is buffered at 4 with phosphoric acid. In Formulation 2, Arlacel and Tween surfactants produce a spillable thickened liquid suspension.

Comparative formulations

Three comparative formulations (A, B and C) were prepared with the following compositions:

016 840

<td rowspan="2"></td><td colspan="3">Formulated</td>

<td>TO</td><td>B</td><td>C</td>

<td>H2O2 (6%)</td><td> 87%</td><td> 87%</td><td> 67%</td>

<td>Acid p- (n-octa-</td><td></td><td></td><td></td>

<td>noyloxy) benzoic</td><td> 0</td><td> 0</td><td> 0</td>

<td>Acid p- (n-octa-</td><td></td><td></td><td></td>

<td>noyloxy) benzene-</td><td></td><td></td><td></td>

<td>sulfonic</td><td> 0</td><td> 13</td><td> 0</td>

<td>Water</td><td> 13</td><td> 0</td><td> 13</td>

<td>Arlacel 83</td><td> 0</td><td> 0</td><td> 12</td>

<td>Tween 40</td><td> 0</td><td> 0</td><td> 8</td>

<td>pH</td><td> 4</td><td> 4</td><td> 4</td>

Formulation B is a duplicate of Formulation 1 except that instead of an insoluble activator, as this invention requires, a solubilized sulfonic acid already described is used as activator (US Patent 4,412,934). Formulas A and B do not contain activators but they are also ideal for Formulas 1 and

2.

The two formulations of the invention and the three comparative formulations were tested as bleach in washings at room temperature at pH values ​​from neutral to basic. It was observed that Formulas 1 and 2 dissolved completely in the washing liquid and together with Formulation B gave positive bleaching results while Formulas A and C, which lacked activators, did not produce acceptable bleaching at low temperatures.

The stability of the formulations was then determined. Formulated B, which contains the activator provided with soluble sulfonate groups, gives off rapidly (5 days at 21 ° C, 70 ° F), (1 day at 38 ° C, 100 ° F), an intense peroxide odor and develops a objectionable layer of oil rich in peraid. Formulated B also swells its plastic container, indicating that oxygen gas has been generated. Obviously, the system is unstable.

Surprisingly, Formulas 1 and 2 of the invention have been apparently stable. Formulas A and C, which have unacceptable results as bleaching, have no visible indications of instability.

The stability of the hydrogen peroxide was measured by titrations with citric sulfate, with the results shown in Table II. The peroxide concentration was measured by titration with cold thiosulfate. The stability of the benzoic acid ester was determined directly by measuring the generation of peracid by those formulated when added to a solution at high pH (pH = 10.5). The amount of peroctanoic acid generated by addition of 2 g of Formulas 1 and 2 to 500 ml of tampoin at pH 10.5 is found in Table III.

TABLE II

H stability₂OR₂

<td rowspan="2"></td><td>Formulated 1</td><td colspan="4">Formulated two</td>

<td> 21^or C</td><td colspan="2"> 21^or C</td><td colspan="2"> 38^or C</td>

<td>Weather</td><td>Exp.</td><td>Exp.</td><td>With-</td><td>Exp.</td><td>With-</td>

<td></td><td></td><td></td><td>troll</td><td></td><td>troll</td>

<td>(days)</td><td></td><td colspan="2">(ml H2O2)</td><td></td><td></td>

<td> 0</td><td> 1,85</td><td> 1,24</td><td> 1,37</td><td> 1,27</td><td> 1,41</td>

<td> 5</td><td></td><td> 1,26</td><td> 1,39</td><td> 1,23</td><td> 1,36</td>

<td> 7</td><td> 1,82</td><td></td><td></td><td></td><td></td>

<td> 9</td><td></td><td></td><td> 1,41</td><td> 1,16</td><td></td>

<td> 14</td><td></td><td> 1,16</td><td> 1,41</td><td> 1,16</td><td> 1,32</td>

<td> 20</td><td> 1,74</td><td></td><td></td><td></td><td></td>

<td> 24</td><td></td><td> 1,18</td><td> 1,37</td><td> 1,08</td><td> 1,32</td>

TABLE III

Peraidic generation after 14 days of storage

<td rowspan="2"></td><td>Formulated 1</td><td colspan="2">Formulated two</td>

<td> 21^orC</td><td> 21^or C</td><td> 38^or C</td>

<td>Peroxide generated (ml)</td><td>1.93x 10^-3</td><td>1.72x10^-3</td><td>1.26x10^-3</td>

<td>Peroxide theoretical generable (ml)</td><td>1.97x10^-3</td><td>1.97x10^-3</td><td>1.97x10^-3</td>

<td>% of the theoretical generated</td><td> 98</td><td> 87</td><td> 64</td>

The half-lives (semi-decomposition periods) extrapolated approximately H2O2 for the Formulated1 to 21^°C (70^°F) and for Formulated 2 to 21^°C (70^°F) and 38^°C (100^°F) are, respectively, 325, 325 and 150 days. The efficient generation of peroctanoic acid after storage of the formulates of this invention demonstrates that the ester does not decompose rapidly in the acid solution.

The rapid generation of peracid from the soluble precursor used in Comparative Formulation B has shown that insolubility of the benzoic acid ester is a primary factor involved in the stabilization of Formulas 1 and 2.

The bleaching agents of this invention can be used to remove stains and dirt from washed clothes and have a good oxygenating bleaching behavior in these applications.

016 840