WO2002083829A1

WO2002083829A1 - Mixed bleach activator compositions and methods of bleaching

Info

Publication number: WO2002083829A1
Application number: PCT/GB2002/001641
Authority: WO
Inventors: Ekram Haque; Carol A. Sheane
Original assignee: Warwick International Group Ltd
Current assignee: Warwick International Group Ltd
Priority date: 2001-04-11
Filing date: 2002-04-08
Publication date: 2002-10-24
Anticipated expiration: 2003-10-11
Also published as: GB0109137D0

Abstract

The present invention provides a bleaching composition comprising a carbonate bleach activator compound of the general structural formula (I) wherein R is selected from the group consisting of C6-24 alkyl, C6-24 alkyl, C6-24 alkenyl, C6-24 alkynyl and C7-24 aralkyl: R1 is a C¿1-12? alkyl group, n is an integer of 0 to 4, M is a cation and m is 1 or 2; and a hydrophilic acyl organoamide bleach activator. The present invention additionally provides a detergent composition and method of bleaching a substrate utilising the above mentioned mixture of bleach activators.

Description

MIXED BLEACH ACTIVATOR COMPOSITIONS AND METHODS OF

BLEACHING

Field of Invention This invention relates to improved bleach activator and bleaching compositions. In particular, the invention relates to novel bleaching and detergent compositions which provide an effective overall bleaching performance on textiles and fabrics over a wide variety of stains.

Background of the Invention

Detergent bleach compositions for washing at higher temperatures are well known in the art. As bleaching agents they normally contain a peroxide compound which liberates hydrogen peroxide in aqueous solution, such as the peroxyhydrates, including alkali metal perborates, percarbonates, perphosphates and persilicates, urea peroxide and the like. These bleaching agents are only effective at higher temperatures of the bleaching solution, i.e. from 80°C up to the boil.

It is known that the bleach activity of peroxide bleach compounds can be improved so as to become effective at lower wash temperatures, e.g. 40- 60°C, by the use of peroxyacid precursors, often also referred to as bleach activators.

Numerous substances have been disclosed in the art as effective bleach activators.

GB patent 855,735, which discloses the broad class of "acyl organoamides", to which the currently most widely used N,N,N'N'-tetraacetyl ethylene diamine (TAED) belongs.

Typically, the substances that have been proposed and utilised as bleach activators are organic compounds which react with the perhydroxide anion (OOH^") of the hydrogen peroxide yielded by the peroxide bleach in the bleaching solution, to form a peroxyacid which is more reactive than the peroxide bleach alone, to effect bleaching at bleach solution temperatures of below 60°C. A particular type of stain which is effectively removed by one specific peroxyacid precursor-hydrogen peroxide combination, may not be as effectively removed by another peroxyacid precursor/H₂0₂ system. Since many classes of soiling are encountered in household and industrial practice, there is not one single bleach activator which is effective on all sorts of bleachable soiling and stains. Domestic soils contain hydrophilic and hydrophobic components.

Various attempts have been made to improve the overall bleaching performance on fabrics over a wide range of stains and soilings by bleach system combinations, but such attempts have in general met with only limited success and/or specific drawbacks.

A continuing trend towards even lower wash temperatures has furthermore presented a constant need for peroxide bleaches with real efficacy at temperatures of 40 °C and therebelow. EP-A-0257700 (Unilever) discloses the use of a bleach system comprising a percompound and a mixture of TAED and sodium nonanoyloxy benzene sulphonate.

EP-A-0202698 discloses a novel p-sulphophenyl alkyl carbonate, having an alkyl group containing 6 to 10 carbon atoms. Detergent compositions containing this type of activator are disclosed.

Summary of Invention

The present invention provides a bleaching composition comprising a carbonate bleach activator compound of the general structural formula (I)

wherein R is selected from the group consisting of C₆.₂₄ alkyl, C₆.₂₄ alkenyl, C₆.₂ alkynyl and C₇.₂₄ aralkyl; R¹ is a ₂ alkyl group, n is an integer of 0 to 4, M is a cation and m is 1 or 2; and a hydrophilic acyl organoamide bleach activator.

The present invention additionally provides a detergent composition and a method of bleaching a substrate utilising the above mentioned mixture of bleach activators.

Detailed Description of the Invention

In compound (I), group R is preferably a C₆.₁₂, more preferably C₆.₁₀, most preferably C₈ alkyl group. R may be branched or linear, preferably linear. Where R is branched, R is preferably 2-ethylhexyl. In any aralkyl group R the aryl part may be substitute, for instance by C.,_₁₈ alkyl, preferably

Ce-12 ^a'^y'' ^but '^s P^ref^erab'y unsubstituted.

R¹ is preferably a C,.₆ alkyl group, most preferably a methyl or ethyl group. n is preferably an integer of 0 or 1 , most preferably 0. M is selected from the group consisting of alkali metals, alkaline earth metals and ammonium groups, more preferably alkali metals, most preferably sodium.

Preferred compounds of formula (I) are sodium or potassium p-(sulphophenyl n-octyl) carbonate, sodium or potassium p-(sulphophenyl n- nonyl) carbonate, and sodium or potassium p-(sulphophenyl n-decyl) carbonate.

Most preferably, compound (I) is sodium p- (sulphophenyl /7-octyl) carbonate.

The hydrophilic acyl organoamide is an amide derived from an organic carboxylic acid and an organic group substituted amine compound containing at least one acyl group attached to the nitrogen atom.

By hydrophilic acyl organoamide is meant that it is the peracid of the acyl group which is hydrophilic.

Examples of peroxyacid precursor compounds falling under this group are:

(a) N,N-diacetylaniline and N-acetylphthalimide;

(b) N-acylhydantoins, such as N,N'-diacetyl-5,5-dimethylhydantoin; (c) Polyacylated alkylene diamines, such as N,N,N',N'-tetraacetyl ethylene diamine (TAED) and N,N,N',N'-tetraacetyl methylene diamine (TAMD) as disclosed in British Patent No. 907,356;

(d) Acylated glycolurils, such as tetraacetyl glycoluril (TAGU) as disclosed in British Patent No. 1 ,246,338;

(e) alpha-Acyloxy-(N,N')-polyacyl malonamides, such as alpha-acetoxy-(N,N')diacetyl malonamide as disclosed in U.S. Patent No. 3,183,266.

The acyl organoamide generally has the structural formula R²CONR³R⁴, in which R² is selected from Q, ₂ alkyl, C₂.₁₂ alkenyl and C₂.₁₂ alkynyl groups, R³ is a second acyl radical and R⁴ is selected from C^ alkyl, C₂.₁₂ alkenyl and C₂.₁₂ alkynyl groups, any of which may be substituted with one or more mono-or di- acyl amino groups.

Preferably, the acyl organoamide comprises two amide groups linked through an alkanediyl group.

In a particularly preferred embodiment, the acyl organoamide has the structural formula (II)

wherein R⁵ is a C,^ alkanediyl group, preferably an ethanediyl group, and each R⁶is individually selected from a C,_₆ alkyl group, preferably methyl, ethyl or propyl. Preferably all R⁶are the same. Most preferably, the acyl organoamide is N,N,N',N'-tetracetylethylene diamine (TAED).

The above mentioned compounds are advantageously incorporated into a detergent composition which, in addition to the bleach activators, contains a bleaching agent, which under alkaline conditions generates hydrogen peroxide.

Examples of suitable, commonly used bleaching agents include alkali metal percarbonate, perborate, persilicate, perphosphate, persulphate and perpyrophosphate, herein after "percompounds". A preferred bleaching agent is sodium percarbonate.

The bleaching agent can be present in the detergent composition in amounts of from 5-99% by weight. The detergent composition of the invention may consist solely of a percompound and the bleach activator mixture when used as a pure bleach product or as a bleach additive to detergent compositions. In that case the composition will comprise from 50-99% percompound and from 50-1 % of the bleach activators, and optional diluents. Generally, compound (I) is present in a detergent composition in an amount of 0.1 to 50% by weight, preferably 0.5 to 10% by weight, most preferably 1 to 2% by weight.

Generally, the organoamide is present in a detergent composition in an amount of 0.1 to 50% by weight, preferably 0.5 to 10% by weight, most preferably 3 to 5% by weight.

Preferably the detergent composition will contain at least one surface-active agent selected from the group consisting of soaps, synthetic anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof, in an amount of from about 2 to 40% by weight of the composition.

Generally, mixtures of the above surface-active agents are used; mixtures of synthetic anionic, synthetic nonionic surfactants and soap are commonly used.

Suitable anionic surfactants are alkali metal soaps of fatty acids, fatty acid-protein condensation products, primary or secondary alkyl sulphates, fatty-acid alkanolamide sulphates, sulphated alkyl- or alkylphenol-polyglycolethers, fatty acid isethionates, fatty acid taurides, alkylbenzene sulphonates, alkane sulphonates, olefin sulphonates, salts of alpha-sulpho fatty acids and esters thereof, and other known surface-active compounds of the sulphate and sulphonate type.

Suitable examples of nonionic surfactants are alkyl and acyl polyglycolethers, alkylphenol polyglycolether, fatty acid alkanolamides and their ethoxylated products, ethoxylated polypropylene glycolethers, amine oxides and fatty acid sugar esters.

The bleach activators according to the present invention commonly are presented in a detergent matrix. Alternatively, the bleach activators according to the invention may be used perse in a detergent composition. Usually the total amount of detergency matrix in a detergent composition of the invention will be from about 5% to about 70% by weight of the detergent composition.

Examples of known detergent matrices are based on sodium tripolyphosphate, sodium orthophosphate, sodium pyrophosphate, sodium trimetaphosphate, sodium ethane-1-hydroxy-1 ,1-diphosphonate, sodium carbonate, sodium silicate, sodium citrate, sodium oxydiacetate, sodium nitrilotriacetate, sodium ethylenediaminetetraacetate, sodium salts of long-chain dicarboxylic acids, for instance straight-chain (C₁₀ to C₂₀) succinic acids and malonic acids, sodium salts of alpha-sulphonated long-chain monocarboxylic acids, sodium salts of polycarboxylic acids, i.e. acids derived from the polymerization or copolymerization of unsaturated carboxylic acids and unsaturated carboxy acid anhydrides such as maleic acid, acrylic acid, itaconic acid, methacrylic acid, crotonic acid and aconitic acid, and the anhydrides of these acids, and also from the copolymerization of the above acids and anhydrides with minor amounts of other monomers, such as vinyl chloride, vinyl acetate, methyl methacrylate, methyl acrylate and styrene, polyacetal carboxylates, and, modified starches such as starches oxidized, for example, using sodium hypochlorite, in which some anhydroglucose units have been opened to give dicarboxyl units.

Another type of detergent matrix which can be used, either alone or in admixture in the detergent composition with other materials useful as builders, is a cation-exchange material, especially a sodium aluminosilicate such as described in GB Patent No. 1 ,429,143 or in Netherlands Patent Application No. 7403381.

Preferred materials of this type have the formula: (Na₂0) o_{/ Λ}Λ\₂0₃(S\0₂) ^ ₃.₃.₃ and may be amorphous or crystalline, with some bound water usually in an amount of about 10-30% depending on the drying conditions used. Such water-insoluble aluminosilicate cation-exchange materials are available as very finely divided powder, commercially known under various grades of zeolites, e.g. Zeolite A and Zeolite B.

Furthermore, any other non-interfering ingredients normally used in detergent compositions in minor amounts, which serve to improve the bleaching and laundering characteristics of the composition or which add aesthetic appeal to the composition, may also be incorporated.

One such important minor ingredient serving to improve the bleaching and laundering characteristics is a peroxide stabilising agent usually a heavy metal sequestrant such as ethylene diamine tetra(methylene phosphonic acid) or its alkali metal salts as disclosed in GB Patent No. 1 ,392,284, and other selected types of compounds as disclosed in GB Patent No. 2,033,937.

Other minor ingredients can include washing alkalis and buffering agents, sequestering agents such as EDTA, polymeric co-builders, suds-controlling agents, soil-suspending agents and anti-redeposition agents, enzymes, particularly proteolytic enzymes, corrosion inhibitors, optical brighteners, colouring agents, heavy metal catalysts, perfumes, bacteriostats and filler materials.

Generally, such minor components comprise no more than about 20% by weight of the bleach composition. The detergent composition according to the invention may be in a form-varying from-powdered to granular and may be prepared by methods known in the art, such as crystallisation or spray drying of an aqueous slurry or mechanical mixing of the substances.

The invention is not confined to solid detergent compositions but also comprises liquid detergent compositions containing the present bleaching activators. The present bleaching activators may also be added separately, in the form of a detergent additive containing the bleach activators, to aqueous wash liquor containing at least a surfactant and a hydrogen peroxide generating bleaching agent. To this end the bleach activators may be applied in the form of powder, granule preferably provided in a matrix, such as described above or in the form of a solution or dispersion. The bleaching activator may also be used in the form or a coated particle. Examples of suitable coating materials are ethoxylated fatty acids and poly(ethylene oxide). The present invention also includes methods of bleaching fabrics and textiles in which the bleach composition and a bleaching agent are dissolved into the water to form a detergent liquor, which is then contacted with the fabric or textiles.

The present invention has particular utility in the fields of laundry and textile bleaching and cleaning. In particular, the invention has been shown to be particularly effective in the bleaching and cleaning of laundry and textiles comprising both hydrophilic and hydrophobic stains. This is due to the hydrophobic nature of the carbonate bleach activator and the hydrophilic nature of the acyl organoamide. The present invention will now be described with reference to the examples.

Example 1

A4% TAED/1 % SC905 (sodium-4-(sulphophenyl octyl) carbonate) mixed system was tested to investigate wash benefits are obtained at 40°C under European conditions (8 g/l concentration of wash components).

A blank formulation containing WMP base detergent formulation and sodium percarbonate PCS was carried out. The % stain removal results of this wash were deducted from that of the mixed activator systems and also from those of the individual components. These results were used to assess the actual benefits seen from each formulation. Washes were carried out using a Miele domestic laundry washing machine at 40°C, using the short wash, cotton cycle. Details of swatches used follows the tables. Graphical results can be found in Figures 1 , 2 and 3.

Formulation Details

Swatch details Bleachable Stains:

CS15 - tomato Detergency Responsive Stains:

AS9 - pigment / oil (<60°C)

AS12 - an overall performance monitor for all temperatures. Has a low concentration of milkpowder and therefore also has a small (proteolytic) enzyme response. AS12 also responds to builder/water hardness, oxidising bleaches (slightly), wash time and product concentration.

E101 - olive oil / carbon black stains.

E116 - blood / milk / carbon black stains. Fixing of this stain can, in some circumstances, be used as a measure of bleach performance.

WFK10C - soiled cotton, WFK soil

WFK10P - red pepper

Stain removal was assessed by %Z Brightness using the Spectraflash 500. The results of the 4% TAED/1 % SC905 mixed system confirmed the complimentary effects seen during evaluations. This will be due to the presence of hydrophilic (TAED) and hydrophobic (SC905) activators, which will work over a wide range of stains. The mixed system also showed improved overall performance over the sum of the individual components.

The 4% SNOBS/1% SC905 mixed system did not show any overall complementary effects.

Example 2 Following on from the evaluation of mixed activator systems under

European conditions for patent data, tests of SC905 (sodium-4-(sulphophenyl octyl) carbonate) plus TAED under Asia Pacific conditions were carried out. The testing was carried out using two different levels of activator, 2.5%/2.5% and 4%/1 % TAED/SC905 to ensure that a full performance profile was completed.

A blank formulation containing Maxkleen 9 base detergent formulation and sodium percarbonate (PCS) was tested and used as the baseline stain removal to determine whether any improvements were seen.

Washes were carried out using a Japanese domestic laundry washing machine at 30°C, using the soak normal cycle, medium fill. Details of swatches used follows the tables. Graphical results can be found in Figures 4, 5, 6 and 7.

Formulation Details

Action Plan 3 Washes - Stain Removal as % Z Brightness

Difference in Stain Removal Compared to Base & PCS Formulation

Action plan 4 Washes - Stain Removal as % Z Brightness

Difference in Stain Removal Compared to Base & PCS Formulation

Swatch details - as Example 1 , plus Bleachable Stains: CS11 Redcurrant Juice

CS14 Morello Juice

CS15 Bilberry Juice

The results of the 2.5% TAED/2.5% SC905 mixed system confirmed the improvement in bleachable stain removal, compared to the sum of the individual activators as seen during the European evaluation.

The 4% TAED/1% SC905 mixed system did not show any overall complimentary effects, although there was a slight improvement in stain removal when compared to TAED alone. This was the ratio of SC905 and TAED which showed benefits under European conditions (Example 1 ). In conclusion, the mixed activator system consisting of 2.5% SC905 plus 2.5% TAED showed improved stain removal under Asia Pacific conditions compared with the sum of the individual activators.

Claims

1. A bleaching composition comprising a bleach activator compound of the general structural formula (I)

wherein R is selected from the group consisting of C₆.₂₄ alkyl, C₆.₂₄ alkenyl, C₆.₂₄ o alkynyl and C₇.₂₄ aralkyl; R¹ is a C ₂ ^a' group, n is an integer of 0 to 4; M is a cation and m is 1 or 2; and a hydrophilic acyl organoamide bleach activator.

2. A bleaching composition according to claim 1 , wherein group R is a C₆.₁₂, more preferably C₆.₁₀, most preferably C₈ alkyl group. 5

3. A bleaching composition according to claim 1 or 2, wherein R is linear.

4. A bleaching composition according to claims 1 , 2 or 3, wherein R¹ is a C^e alkyl group, most preferably a methyl or ethyl group.

5. A bleaching composition according to any preceding claim, o wherein n is an integer of 0 or 1 , preferably 0.

6. A bleaching composition according to any preceding claim, wherein M⁺ is sodium or potassium, preferably sodium.

7. A bleaching composition according to any preceding claim, wherein compound (I) is sodium p-(sulphophenyl "octyl) carbonate. 5

8. A bleaching composition according to any preceding claim, wherein the hydrophilic acryl organoamide has the structural formula R²CONR³R⁴, in which R² is selected from 0 _A2 alkyl, C₂.₁₂ alkenyl and C₂.₁₂ alkynyl groups, R³ is a second acyl radical and R⁴ is selected from C,_₁₂ alkyl, C₂.₁₂ alkenyl and C₂.₁₂ alkynyl groups, any of which may be substituted with one 0 or more acyl organoamide groups.

9. A bleaching composition according to claim 8, wherein the hydrophilic acyl organoamide has the structural formula (II)

5 wherein R⁵ is a C,._e alkanediyl group, preferably an ethanediyl group, and each R⁶ is individually selected from a C,.₆ alkyl group, preferably methyl, ethyl or propyl.

10. A bleaching composition according to claim 8 or 9, wherein the hydrophilic acyl organoamide is N, N, N^', N^'-tetracetyl ethylenediamine. o

11. A detergent composition comprising a bleaching composition as defined in any preceding claim and a bleaching agent.

12. A detergent composition according to claim 11 , wherein the bleaching agent is selected from alkali metal percarbonate, perborate, persilicate, persulphate, perphosphate and perpyrophosphate preferably 5 sodium parcarbonate.

13. A detergent composition according to claim 11 or 12, additionally comprising a surfactant.

14. A detergent composition according to any of claims 11 to 13, wherein the surfactant is selected from the group consisting of soap, synthetic o anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof, in an amount of from about 2 to 40% by weight of the composition.

15. A detergent composition according to any of claims 11 to 14, wherein mixtures of surfactants are used.

16. A detergent composition according to any of claims 11 to 15, 5 additionally comprising a detergency builder.

17.. A method of bleaching laundry or textiles in which a bleach composition according to any of claims 1 to 10 and a bleaching agent are dissolved into water to form an aqueous detergent liquor and the liquor is then contacted with the laundry or textiles. 0

18. A method according to claim 17, additionally comprising the addition of a surfactant to the wash liquor, the surfactant optionally being presented in the same composition as the bleach activators and/or the bleaching agent.

19. A method according to claim 17 or 18, wherein the laundry/textiles have hydrophilic and hydrophobic stains.