EP0106634A1

EP0106634A1 - Bodies containing bleach activators

Info

Publication number: EP0106634A1
Application number: EP83306046A
Authority: EP
Inventors: Stanley Yat-Ming Chung; Gianfranco Luigi Spadini
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1982-10-08
Filing date: 1983-10-05
Publication date: 1984-04-25
Also published as: ES526333A0; DE3364205D1; ES8504242A1; EP0106634B1

Abstract

The invention relates to bodies containing bleach activators. In particular, this invention relates to bodies containing bleach activators which comprise specific bleach activators and binder material. In such bodies said bleach activators have excellent storage stability and, yet, maintain excellent dispersibility in wash water.

Description

BACKGROUND TO THE INVENTION

The present invention relates to bodies containing bleach activators. In particular, this invention relates to bodies containing bleach activators which comprise specific bleach activators and binder material. In such bodies said bleach activators have excellent storage stability and, yet, maintain excellent dispersibility in wash water.
It has long been known that peroxygen bleaches provide a desirable level of bleaching performance, but that they are also extremely temperature dependent. Such bleaches are essentially only practicable and/or effective in bleaching solutions; i.e., a bleach and water mixture, wherein the solution temperature is above about 60°C. At bleach solution temperatures of about 60°C peroxygen bleaches are only partially effective, due to their low level of reactivity. Therefore, in order to obtain a desirable level of bleaching performance extremely high levels of peroxygen bleach must be added to the system. As the bleach solution temperature is lowered below 60°C, even higher levels of peroxygen bleach must be added to the system in order to obtain a desirable level of bleaching performance. The temperature dependence of peroxygen bleaches is significant because such bleaches are commonly used as a detergent adjuvant in textile wash processes that utilize an automatic household washing machine at wash water temperatures below 60°C. Such wash temperatures are utilized because of textile care and energy considerations. As a consequence of such wash processes, there has been much industrial research to develop substances, generally referred to as bleach activators, that render peroxygen bleaches effective at bleach solution temperatures below 60°C. Numerous substances have been disclosed in the art as effective bleach activators.
Carboxylic acid ester bleach activators are known. U. K. Patent 864,798, Hampson et al (April 6, 1961 ), discloses bleaching compositions comprising an inorganic persalt and an organic ester of an aliphatic carboxylic acid wherein the size of the carboxylic acid ester particles are such that at least 70% of them are retained on a 60 mesh British Standard sieve. It is stated that such bleaching compositions are stable during storage. It is preferred that the ester be derived from an aliphatic carboxylic acid having not more than 10, preferably less than 8 carbon atoms.
U.K. Patent 836,988, Davies et al (June 9,' 1960), discloses bleaching compositions containing hydrogen peroxide or inorganic persalt and organic carboxylic esters. A test is described to define the esters within the invention. It is stated that such esters provide improved bleaching at temperatures from 50°C to 60°C relative to that obtained with the persalt alone.
It is also known that peroxygen bleaches in combination with bleach activators that are believed to exhibit surface activity provide particularly effective bleaching performance. U.S. Patent 4,283,301, Diehl (August 11, 1981), discloses bleaching compositions comprising a peroxygen bleach and a bleach activator of the general formula:
wherein R is an alkyl chain containing from about 5 to about 13 carbon atoms, R² is an alkylene chain containing from about 4 to about 24 carbon atoms and each Z is a leaving group as defined therein.
It has also been long known that the function of a bleach activator can be significantly impaired during storage by interaction with the peroxygen bleach and/or moisture and, if the bleach activator is part of a detergent composition, interaction with other components of the detergent composition. Therefore, for the bleach activator to retain its efficacy, it must be protected from its environment during storage. However, any method of protecting the bleach activator from its environment must not substantially inhibit its ability to disperse in the wash water.
U.S. Patent 4,009,113 Green et al, February 22, 1977, discloses granular compositions comprising from about 40% to about 80% of a bleach activator and an inert carrier material such as a long chain fatty acids or esters wherein said precursor is substantially evenly distributed with said precursor compound to form a composite particle. The particle has an outer protective layer which can consist of, for example, polyvinyl alcohol. It is stated that such compositions have both good storage stability and dispersibility in the wash water.
U.S. Patent 4,399,049 Gray et al (Angust 16 1983)discloses a detergent additive composition comprising from about about 75% to about 95% of a particulate infusible solid having a particle size distribution such that at least about 50% thereof passes a 250 micrometer screen and comprising storage sensitive detergent additive materials, and from about 5% to about 25% of ethoxylated nonionic surfactants melting in the range from about 20°C to about 60°C wherein said composition is prepared via a radial extrusion process. It is stated that such compositions have improved storage stability together with excellent release and dispersibility characteristics in wash water.

SUMMARY OF THE INVENTION

The present invention comprises a body containing bleach activators comprising:

(a) from 50% to . 98% of a bleach activator having the general formula:
wherein R is an alkyl group containing from 5 to 18 carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from 6 to 10 carbon atoms and L is a leaving group containing an anionic moiety, wherein the conjugate acid of the anion formed on L has a pK a in the range of from 4 to 13; and
(b) from - 2% to 50% of a binder material selected from the group consisting of nonionic surfactants, polyethylene glycols, anionic surfactants, film forming polymers, fatty acids and mixtures thereof wherein said binder does not melt below 40°C;

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to a body containing bleach activators which comprise specific bleach activators and binder material, both of which are defined hereinafter. The bleach activators in the body have excellent storage stability and, yet, readily disperse in the wash water. Also when the bodies arc-utilized as disclosed in the Applicants pending European patent Application No. 83200938.5.
a superior level of bleaching performance on textiles is obtained. It is essential that the bleach activator and binder material are substantially evenly distributed throughout the body and that the body has the proper density. Experimental evidence indicates that compacting the bleach activator particles to form a body with a density within the invention and then coating it with the binder material does not provide the desired level of storage stability. Only when the bleach activator and binder material are substantially evenly distributed throughout the body is the storage stability excellent. However, it is also essential that the density of the body be above 1.06 grams /cubic centimeter (g/cc), preferably above 1.08 g/cc, most preferably from 1.10 g/cc to 1.30 g/cc. Experimental evidence also indicates that though the bleach activator and binder material are substantially evenly distributed throughout the body, densities below 1.06 g/cc do not provide the desired level of storage stability. It should be noted that the specific densities were measured by a mercury displacement method in which air is removed from a vessel containing a weighed sample of the particles (bodies), mercury is introduced, and the pressure increased in increments. The rate of volume decrease (or density increase) is typically one value when interparticulate spaces are being filled, which occurs first, and a different value when the voids in the particle are being filled. The inflection point on the volume- pressure curve is taken as indicating the specific density of the particles.
The body must also be essentially free of moisture. The presence of excess free moisture will result in very poor storage stability because of the bleach activator's susceptability to hydrolysis. Thus, the body must contain less than 3% water and preferably less than 1.5% water.
Control of the particle size of the body is also of some importance for securing optimum storage stability and dispersibility in the wash water. It is preferred that the bodies have a particle size distribution from 0.05mm to 2.5 millimeters wherein no more than 5% of the bodies are greater than 2 millimeters and more preferably from 0.30 mm to 1.5 millimeters.
The body can be made by essentially any apparatus that is suitable to substantially evenly distribute the bleach activator and binder material throughout the. body and compact the body in order to obtain the required density. For example, powder blenders can be utilized to mix the bleach activator and binder material and then the mixture can be passed through a radial or axial extruder or a compaction press to form the body. Radial or axial extruders are preferred because it is believed that they produce a body in which the bleach activator has both superior storage stability and dispersibility in the wash water. It should be noted that when the bleach activator and binder material are mixed, the binder material should be in fluid form. This can be accomplished by either heating the mixture until the binder material melts or, especially with binder materials that decompose rather than melt upon heating, forming an aqueous solution.
The following is a detailed description of the essential components of the body containing bleach activators within the invention. All percentages, parts and ratios are by weight unless otherwise indicated.

The Bleach Activator

The bleach activators that can be utilized in the bodies within the invention have the general formula:
wherein R is an alkyl group containing from 5 to 18 carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from 6 to
10 carbon atoms and L is a leaving group that contains an anionic moiety, the conjugate acid of which has. a pK a in the range of from 6 to 13.
L can be essentially any suitable leaving group that contains an anionic moiety. A leaving group is any group that is displaced from the bleach activator as a consequence of the nucleophilic attack on the bleach activator by the perhydroxide anion. Generally, for a group to be a suitable leaving group it must exert an electron attracting effect. This facilitates the nucleophilic attack by the perhydroxide anion yielded by the peroxygen bleach which is believed to be essential in order to obtain a superior level of bleaching performance. Leaving groups that exhibit such behavior are those in which their conjugate acid has a pK a in the range of from 6 to 13, preferably from 7 to 11 and most preferably from about 8 to about 11. Also, in order for the body to have the desired level of dispersibility in the wash water it is essential that the leaving group contain an anionic moiety. A leaving group that does not contain an anionic moiety does not provide the desired level of dispersibility in the wash water. Nonlimiting examples of suitable anionic moieties are
-COO M and
wherein M is a compatible cation.
Preferred bleach activators are those of the above general formula wherein R is as defined in the general formula and L is selected from

wherein R is as defined above, R is an alkyl chain containing from 1 to 8 carbon atoms, R is H or R², and Y is selected from
-COO^-M⁺ and
and most preferably
and -COO^-M⁺, M is selected from alkali metals, ammonium and substituted ammonium cations, with sodium and potassium being most preferred.
Preferred bleach activators are also those of the above general formula wherein L is as defined in the general formula and R is an alkyl group containing from 5 to 12 carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from 6 to 10 carbon atoms.
Even more preferred are bleach activators of the above general formula wherein L is as defined in the general formula and R is a linear alkyl chain containing from 5 to 9 and preferably from 7 to 9 carbon atoms.
More preferred bleach activators are those of the above general formula wherein R is a linear alkyl chain containing from 5 to 9 and preferably from 7 to 9 carbon atoms and L is selected from
wherein R, R², R and Y are as defined above.
Particularly preferred bleach activators are those of the above general formula wherein R is an alkyl group containing from 5 to 12 carbon atoms wherein the longest linear portion of the alkyl chain extending from and including the carbonyl carbon is from 6 to 10 carbon atoms and L is selected from
wherein R is as defined above and Y is
or -COO M wherein M is as defined above.
Especially preferred bleach activators are those of the above general formula wherein R is a linear alkyl chain containing from 5 to 9 and preferably from about 7 to about 9 carbon atoms and L is selected from
wherein R² is as defined above and Y is -
or -COO^-M⁺. wherein M is as defined above.
The most preferred bleach activators have the formula:
wherein R is a linear alkyl chain containing from 5 to 9 and preferably from 7 to 9 carbon atoms and M is sodium or potassium.
The level of bleach activator within the bodies of the invention is from . 50% to 98% and preferably from 85% to 96%. It is also preferred that the bleach activator particle size distribution is from 5 microns to 2.5 millimeters wherein no more than 2% of the particles are greater than 2 millimeters and more preferably from 25 microns to 150 microns.

The Binder

The materials that can be utilized as binders are nonionic surfactants, polyethylene glycols, fatty acids, anionic surfactants, film forming polymers and mixtures thereof. It is believed that such binder materials are not reactive with the bleach activator and, if in a detergent composition, not reactive with the components of the detergent composition upon storage. Also, they have low hygroscopicity upon storage and, yet, are soluble and, therefore, dispersible in the wash water. However, it is essential that such binder materials do not melt below about 40°C. Otherwise, the binder is likely to melt upon storage because often the storage temperature is as high as 40°C. Naturally, the melting of the binder material results in the bleach activator being quite unstable. It should be noted that some of the binder materials within the invention will decompose rather than melt upon the application of heat energy. However, the temperature at - which such binder materials decompose is well beyond any temperature at which the bodies will be stored.
Nonionic surfactants are the least preferred binder materials because it is believed that they have an inimical effect on cleaning performance on textiles when the bodies are utilized as disclosed in the Applicants pending European patent Application No. 83200938.5.
Examples of nonionic surfactants that can be utilized as a binder material are the condensation product of primary or secondary aliphatic alcohols having from 8 to 24 carbon atoms, in either straight chain or branched chain configuration, with from 35 to 100 moles, preferably 40 to about 80 moles of ethylene oxide per mole of alcohol. Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms and is ethoxylated with between 35 and 100, desirably between 40 and 80 moles of ethylene oxide per mole of aliphatic alcohol. The preferred nonionic surfactants are prepared from primary alcohols which are either linear (such as those derived from natural fats or, prepared by the Ziegler process from ethylene, e.g., myristyl, cetyl, stearyl alcohols), or partly branched such as the Dobanols and Neodols which have about 25% 2-methyl branching (Dobanol and Neodol being Trade Names of Shell or Synperonics, which are understood to have about 50% 2-methyl branching (Synperonic is a Trade Name of I.C.I.) or the primary alcohols having more than 50% branched chain structure sold under the Trade Name Lial by Liquichimica.
Other suitable nonionic surfactants are the polyethylene oxide condensates of alkyl phenol, e.g., the condensation products of alkyl phenols having an alkyl group containing from 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 35 to 100, preferably
40 to 80 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived, for example, from polymerised propylene, di-isobutylene, octene and nonene.
Still further nonionic surfactants suitable for use herein are the compounds formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The molecular weight of the hydrophobic portion generally falls in the range of 1500 to 1800. Such synthetic nonionic detergents are available on the market under the Trade Name of "Pluronic" supplied by Wyandotte Chemicals Corporation.
Suitable polyethylene glycols, which are homopolymers of ethylene oxide having the general formula HO(C₂H₄O)_nH, have an average molecular weight of from 2,000 to 15,000, preferably from 3,000 to 10,000 and most preferably from 4,000 .to 8,000.
The fatty acids that are suitable for use herein are higher fatty acids containing from 8 to 24 carbon atoms and preferably from 12 to 18 carbon atoms. It has also been observed that mixtures of fatty acids and nonionic binder materials,. e.g., polyethylene glycols or nonionic surfactants, provide the bleach activator with particularly good storage stability and dispersibility in the wash water. It is believed that fatty acids reduce the hygroscopicity of the nonionic binder materials and that the nonionic binder materials improve the dispersibility of the fatty acids.
Suitable anionic surfactants are the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from 8 to 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. (lncluded in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates,_ especially those obtained by sulfating the higher alcohols (C8-C18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the sodium and potassium alkylbenzene sulfonates in . which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099 and 2,477,383. The preferred anionic surfactants are linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from 11 to 13, abbreviated as C_11-13LAS.
Other anionic surfactants herein are the water-soluble salts of the higher fatty acids, i.e., "soaps", are useful anionic surfactants in the compositions herein. This includes alkali metal soaps such as the sodium, potassium, ammonium, and alkylolammonium salts of higher fatty acids containing from 8 to
24 carbon atoms, and preferably from 12 to 18 carbon atoms. Soaps can be made by direct saponification of fats and oils or by the neutralization of free fatty acids.
Other anionic surfactants for use herein are the sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfates containing from 1 to 10 units of ethylene oxide per molecule and wherein the alkyl groups contain from 8 to 12 carbon atoms; and sodium or potassium salts of alkyl ethylene oxide ether sulfates containing 1 to 10 units. of ethylene oxide per molecule and wherein the alkyl group contains from 10 to 20 carbon atoms.
Other useful anionic surfactants herein include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from 6 to 20 carbon atoms in the fatty acid group and from
1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-l-sulfonic acids containing from 2 to 9 carbon atoms in the acyl group and from 9 to 23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing from 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group and from 8 to 20 carbon atoms in the alkane moiety.
Suitable film forming polymers are the polymers derived from the monomers such as vinyl chloride, vinyl alcohol, furan, acrylonitrile, vinyl acetate, methyl acrylate, methyl methacrylate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, acrylamide, ethylene, propylene and 3-butenoic acid.
Preferred polymers of the above group are the homopolymers and copolymers of acrylic acid, hydroxyacrylic acid, or methacrylic acid, which in the case of the copolymers contain at least 50%, and preferably at least 80%, by weight of units derived from the acid. The particularly preferred polymer is sodium polyacrylate. Other specific preferred polymers are the homopolymers and copolymers of maleic anhydride, especially the copolymers with ethylene, styrene and vinyl methyl ether. These polymers are commercially available under the trade names Versicol and Gantrez.
Other film-forming polymers useful herein include the 'cellulose sulfate esters such as cellulose acetate sulfate, cellulose sulfate, hydroxyethyl cellulose sulfate, methylcellulose sulfate and hydroxypropylcellulose sulfate.
Surprisingly, very small levels of binder material within the body are required. The level of binder material within the bodies within the invention is from 2% to 50% and preferably from 4% to 15%.

Optional Components

The bodies of the present invention can also contain all of the usual components of detergent compositions including the ingredients set forth in U.S. Patent 3,936,537, Baskerville et af, so long as they are inert with respect to the bleach activator and binder material. Such components include color speckles, suds boosters, suds suppressors, antitarnish and/or anticorrosion agents, soil-suspending agents, soil-release agents, dyes, fillers, optical brighteners, germicides, alkalinity sources, hydrotropes, antioxidants, enzymes, enzyme stabilizing agents, perfumes, etc.
The following examples are given to illustrate the parameters of-and compositions within the invention. All percentages, parts and ratios are by weight unless otherwise indicated.

EXAMPLE I

The following granular detergent composition was prepared:
^*stripped of unreacted alcohol and monoethoxylate
600 parts of the bleach activator powdered sodium linear octanoyloxybenzene sulfonate which passes through a 0.149 mm screen and 180 parts of a binder material consisting of 50% water, 32% C₁₃ linear alkylbenzene sulfonate and 18% sodium sulfate were utilized in a fluidized bed to produce bodies containing the bleach activator of particle sizes that passed through a 0.595mm screen onto a 0.21mm screen. The bodies were then dried to remove all the water. The density of the bodies was then determined via mercury intrusion.
A composition consisting of 86% of the above granular detergent composition, 6% sodium perborate monohydrate and 8% of the bodies was prepared. The composition was placed in a glass jar and stored for four weeks wherein the storage room temperature ranged from 27°C to 32°C and room humidity ranged from 60% to 80%.
10 Grams of the composition was then added to a beaker containing 500 cc. of 37°C water. The water contained 120ppm Ca water hardness. The water was continuously stirred for about 10 minutes and then the amount of available oxygen from percarboxylic acid was measured utilizing an iodometric titration procedure. This measurement was compared to the maximum theoretical amount of available oxygen from percarboxylic acid to determine the percent of the retained reactivity of the bleach activator.
The entire above procedure was repeated but with bodies consisting of 100 parts of the above bleach activator and 18 parts of the above binder material prepared via radial extrusion. The noodle like extrudates were then dried and granulated. The size of the bodies was such that they passed through a 1.68mm screen onto a 0.42mm screen.
Once again the entire above procedure was repeated, but the bodies were prepared by placing 50 parts of the above bleach activator in a mixer and then spraying them with 4 parts water. The bodies were then dried. The size of the bodies was such that they passed through a 1.68nm screen onto a 0.42mn screen. The bodies then were coated with a C₁₃ linear alkylbenzene sulfonate paste binder material.
The results were as follows:
The bodies prepared via the fluid bed have the binder paste substantially evenly distributed throughout the bodies containing the bleach activator, but have a density outside the invention provided poor storage stability for the bleach activator. The bodies prepared via the mixer have a density within the invention, but do not have the binder material substantially evenly distributed throughout the bodies containing the bleach activator did not provide the desired level of storage stability of the bleach activator. Only the bodies prepared via extrusion, which have both a density within the invention and the binder material substantially evenly distributed throughout, the body, provided excellent storage stability for the bleach activator.

EXAMPLE II

A sample of the bodies prepared via radial extrusion in Example I were admixed with the granular detergent composition of Example I. A quantity of sodium perborate monohydrate corresponding to a molar ratio of sodium perborate monohydrate to bleach activator of 3.3 was added to the system. The entire system was then placed in a beaker containing 37°C water.
The amount of available oxygen from percarboxylic acid was measured as in Example 1, 3 minutes, 5 minutes and then 15 minutes after the system was placed in the beaker. Then the percent conversion of sodium linear octanoyloxybenzene sulfonate to percarboxylic acid was calculated for each time period.
The above procedure was repeated with sodium linear octanoyloxybenzene sulfonate powder, tetracetylethylenediamine (TAED) powder and TAED prepared with the same binder material via radial extrusion as i.n Example 1.
The results were as follows:
Bleach Activator System I, which is within the invention, produced higher percentage conversion of activator to percarboxylic acid in a shorter period of time than Bleach Activator System III, which is outside the invention because it did not contain a bleach activator within the invention. It should be noted that though Bleach Activator System III achieved 100% conversion after 15 minutes, that this level of dispersibility would not be sufficient in a textile wash process because .it would not allow enough time for the bleaching process to occur.

EXAMPLE fit

Ten sets of four 12.5 x 12.5 cm swatches consisting of standard textiles and five sets of four terry cloth towels were preconditioned by adding artificial body soils to them so as to simulate the condition of household laundry that has been subjected to routine wear. Each set of four swatches was then stained with a different bleachable stain. The swatches were then cut in half to produce 20 sets of half swatches with half of the stain being on each half of the swatch. One terry cloth towel from each set of terry cloth towels was then soiled with a mixture of artificial body soil and vacuum cleaner soil.
A laundry load consisting of one of the sets of terry cloth towels and four of the sets of half swatches was placed in each of five mini-wash systems. The four sets of half swatches placed in each mini-wash system were chosen so that no half swatch was placed in the same mini-wash system as its original other half.
The laundry load in the first mini-wash system was washed with a quantity of the detergent composition of Example I that corresponds to 1500 ppm in the wash water which is typical of conventional automatic wash processes. The mini-wash system with such a load simulates a conventional automatic wash process. The wash water temperature was 37°C and the rinse water temperature was 22°C and both contained 12Oppm Ca⁺⁺ water hardness.
This wash process was carried out in the other four mini-wash systems, but with each mini-wash system also containing one of the four Bleach Activator Systems of Example II and sodium perborate monohydrate wherein the molar ratio of sodium perborate monohydrate to bleach activator was 3.3.
Each of the swatches was then comparison graded with its original other half to determine relative stain removal. A grading scale of -4 to 4 was used, with -4 indicating much less stain removal, 0 indicating no difference and 4 indicating much more stain removal. The average of the grades for each stain of each mini-wash system was calculated.
The entire above procedure was repeated. The average of the two determinations of each of the above described averages was calculated. Finally, the average of all such averages for each mini-wash system was calculated. The average for each system was then scaled from 0 to 100, with 0 being the mini-wash system that provided the least stain, removal and 100 being the mini-wash system that provided the most stain removal. This number is known as the Bleaching Index.
The results were as follows:
Bleach Activator System 11, which has bodies containing a bleach activator within the invention, not only provided significantly better bleaching performance than Bleach Activator System IV, which has bodies containing bleach activators outside the invention, but significantly better bleaching performance than Bleach Activator System V, which contains a powdered bleaching system.

Claims

1. A body containing a bleach activator comprising:

(a) from 50% to 98% of a bleach activator having the general formula:

wherein R is an alkyl group containing from 5 to 18 carbon atoms wherein the longest linear alkyl chain extending from and including the carbonyl carbon contains from 6 to 10 carbon atoms and L is a leaving group containing an anionic moiety, wherein the conjugate acid of the anion formed on L has a pK_a in the range of from 4 to 13; and

(b) from 2% to 50% of a binder material selected from nonionic surfactants, polyethylene glycols, anionic surfactants, film forming polymers, fatty acids and mixtures thereof wherein said binder does not melt below 40°C;

wherein (a) and (b) are substantially evenly distributed throughout said body, the density of said body is above 1.06 g/cc and said body contains less than 3% water.

2. A body according to Claim 1 wherein said body has a particle . size lying in the range from 0.05mm to 2.5mm wherein no more than 5% of the bodies are greater than 2 millimetres, said particle size range preferably extending from 0.3mn to 1.5mm.

3. A body according to either one of claims 1 and 2 wherein the binder material is selected from water-soluble C_11-13 linear alkylbenzene sulfonates; aliphatic alcohols containing between 9 and 18 carbon atoms ethoxylated with between 40 and 80 moles of ethylene oxide; sodium polyacrylate; polyethylene glycols having a molecular weight of from 2,000 to 15,000, preferably from 4,000 to 8,000; fatty acids containing from 12 to 18 carbon atoms; and mixtures thereof.

4. A body according to any one of claims 1-3 wherein the bleach activator comprises from 85% to 96% of the body and the binder comprises from 4% to 15% of the body.

5. A body according to any one of claims 1 to 4 wherein the density of said body is above 1.08 g/cc, preferably from 1.10 g/cc to 1.30 g/cc.

6. A body according to any one of claims 1-5 wherein the bleach activator has the general formula:

wherein R is a linear alkyl chain containing from 7 to 9 carbon atoms and M is sodium or potassium wherein the bleach activator particle size distribution is from 0.025mm to 0.15mm; and wherein said body contains less than 1.5% water.

7. A body according to any one of claims 1-6 prepared by radial or axial extrusion.