GB2249104A

GB2249104A - Bleach activators

Info

Publication number: GB2249104A
Application number: GB9121773A
Authority: GB
Inventors: Walter Edward Paget
Original assignee: BP Chemicals Ltd
Current assignee: BP Chemicals Ltd
Priority date: 1990-10-23
Filing date: 1991-10-14
Publication date: 1992-04-29
Anticipated expiration: 2011-10-14
Also published as: GB9121773D0; GB2249104B; GB9023006D0

Abstract

This invention relates to a composition comprising bleach activators deposited on an aluminosilicate support. The supports are preferably clays having a lattice-type structure. Such supported bleach activators give superior bleaching performance when used in detergent formulations.

Description

BLEACH ACTIVATORS The present invention relates to bleach activators releasably impregnated on an aluminosilicate support and the use of such supported bleach activators in detergent formulations.

The use of bleach activators such as tetraacetyl ethylenediamine (hereafter "TAED"), sodium nonanoyl oxybenzene sulphonate (hereafter"SNOBS") and the like to enhance the performance of bleaches, especially peroxy bleaches such as sodium perborate, is well known. Such bleach activators readily undergo perhydrolysis in the presence of alkaline hydrogen peroxide to generate the more reactive bleaching species. The general effect of such bleach activators is to bring about significant reduction in the wash temperatures. However, the performance of such activators generally declines with a reduction in wash temperatures. Some attempts to mitigate this problem have been made by using the more reactive preformed peracids as the bleaching species. However, peracids have limited stability and present safety hazards during storage and handling.

More recently, cyclic anhydrides and related compounds have been proposed as active precursors for the generation of the desired active bleaching species during the wash. Such compounds are described in our prior published EP-A-331300 and EP-A-332294.

It has now been found that the rate of perhydrolysis of the bleach activators to generate the desired bleaching species can be enhanced by depositing the activator on a support.

Accordingly, the present invention relates to a composition comprising a perhydrolysable bleach activator releasably deposited on an aluminosilicate support.

The bleach activators which can be deposited on a support include TAED, SNOBS, sodium isononanoyl benzene sulphonate (hereafter "ISONOBS"), and compounds of the formulae (I), (II), (III), or (IV) below:

R1-CO-N(R5)-R2-CO-L (III) R1-N(R5)-CO-R2-CO-L (IV) wherein: a) the notations Q in formulae (I) and (II) represent a divalent organic grouping such that Q and N together with the carbonyl and oxygen functions form one or more cyclic structures and in (I) R is H, an alkyl, aryl, halogen, a carboxylic or a carbonyl containing function, and in (II) R is a C2 or higher alkyl, alkaryl, aralkyl, alkoxyl, haloalkyl, alkylamino, dialkylamino, carboxylic or a carbonyl-containing function; b) in formulae (III) and (IV) R1 is an alkyl, aryl, alkyloxy or an aryoxy group, R2 is an alkylene or an arylene group, R5 is H, an alkyl, aryl, halogen, a carboxylic or a carbonyl containing function, and L is a leaving group such that when the bleach activator is in an aqueous alkaline medium and in the presence of a bleach precursor capable of giving rise to peroxy compound in an aqueous medium, the compounds (III) and (IV) are transformed into the corresponding percarboxylic acids.

Of these, compounds of the formula (I) above are described in our prior published EP-A-331300. A specific example of such a compound is isatoic anhydride.

Compounds of the formula (II) above are described in our prior published EP-A-332294. Specific examples of compounds of this type include the 2-alkyl, 2-dialkylamino and the 2-aryl derivatives of 3,1-H benzoxazin-4-one.

Compounds of the formulae (III) and (IV) are described in the prior published EP-A-170386. Specific examples of such compounds include N-lauroyl aminocaproic acid, 6-decylamino-6-oxo caproic acid and 6-benzoyl aminocaproic acid.

The bleach activators falling within the formulae (I)-(IV) above and described in three published European patents referred to above are incorporated herein by reference.

The support is an aluminosilicate, preferably a zeolite or a clay. These may be amorphous or crystalline. The supports which may be used in the present invention include the bentonite clays such as the grades ASB-60, -60S, -350 (all ex English China Clays), montmorillonites whether or not acid washed, kaolinite, hectorite, and Veegum (ex Steetley Minerals, UK) and zeolites such as Wesselith P (ex Degussa). Clays which have a lattice-type structure are most preferred.

The amount of bleach activator deposited on the support is suitably from 5-95Z w/w of the total including the support.

The bleach activator can be suitably deposited on the support by any of the conventional methods such as impregnating the support with a solution or a fine emulsion or dispersion of the activator in a carrier solvent. The solvent used should preferably be such that it is readily removed from the support after impregnation so that the activator is readily deposited on the support. Specific examples of the solvents include alcohols, ethers, ketones and esters which are preferably aliphatic; hydrocarbons which may be aliphatic or aromatic; or mixtures thereof. Thus, typically, the bleach activator may be dissolved or dispersed in a compatible solvent (i.e. the solvent is inert and does not alter the chemical or physical characteristics of the activator) and the aluminosilicate support e.g. clay or zeolite is uniformly dispersed into the solution of the activator.After impregnation, the solvent/carrier can be removed from the support e.g. by evaporation or distillation to leave behind a dry solid which is the bleach activator deposited on the support. This dry solid can then be ground to the desired particle size at the same time removing any coarse lumps or agglomerates.

Specific examples of the solvents that may be used include C1-C4 alcohols such as ethanol or methanol, aromatic hydrocarbons such as toluene or xylene or mixtures thereof.

The supported activator so produced can be mixed with conventional detergent powder bases containing detergents, builders, alkaline washing agents, and a source of hydrogen peroxide such as e.g. sodium perborate or percarbonate. The mixture thus formulated can be used for washing clothes and fabrics.

Thus according to a further embodiment the present invention is a detergent formulation comprising: (a) a surfactant selected from anionic, nonionic, zwitterionic and mixtures thereof, (b) a precursor compound capable of giving rise to a peroxygen compound in the presence of water, (c) a bleach activator capable of enhancing the bleaching activity of the peroxygen compound so formed, (d) a suds suppressing agent and (e) a detergent builder, characterised in that the bleach activator is releasably deposited on an aluminosilicate support prior to incorporation in said formulation.

The supported bleach activator used in the detergent formulations of the present invention has an average particle size in the range from 35 to 420 micrometers, preferably from 60 to 250 micrometers.

A surprising feature of this invention is that using the bleach activator and the aluminosilicate support separately in the formulation is relatively ineffective when compared with the high performance of the supported activators of the present invention.

Specific examples of conventional activators which can be used in the present invention include SNOBS, ISONOBS, and the compounds of formulae (I), (II), (III) and (IV) described above. In particular, the performance of the 2-substituted 3,1(4H)-benzoxazinone derivatives of formula (II) in which the 2-position is substituted by a hydrocarbyl group containing at least three carbon atoms whether attached directly as in the case of 2-alkyl or 2-aryl benzoxazinones or through a heterocyclic atom, which maybe nitrogen or oxygen, such as e.g. the 2-N,N-dialkylamino group, which contain at least three carbon atoms of the alkyl substituents is significantly improved.Similarly, the bleach activators of the isatoic anhydride type which fall within and formula (I) in which the 5- or 6- positions are substituted by a hydrocarbyl group containing at least 3 carbon atoms whether attached directly or through a hetero-atom, e.g. nitrogen or oxygen, can show improved in performance.

In the detergent formulations of the present invention, the concentration of the various components (a) to (e) and the method of formulating the same are conventional and are specifically claimed and described in our prior published EP-A-331300 and EP-A-332294.

Thus in respect of the detergent formulations of the present invention, the matter disclosed in these prior publications are incorporated herein by reference to these European patent specifications. In this context the amount of bleach activator specified in these prior publications should be construed as such in the present invention and that amount of the supported activator should be used which will represent the desired concentration of the bleach activator (excluding the support).

The present invention is further illustrated with reference to the following Examples: A. Preparation of the supported activator according to the invention: 3.0g of ASB-60S clay (ex English China Clays), 0.5g of 2PB4 were weighed in and mixed together as dry powder and to this was added 18g of ethanol and 5g of toluene. This was stirred and heated on a boiling water bath until a homogeneous dispersion was achieved. This mixture was evaporated to dryness in a Bucchi rotary evaporator distillation unit under reduced pressure using a boiling water bath. This took about 20 minutes. The resultant solid was ground into a fine powder using a pestle and mortar. The ground sample was used fresh for their activity.

B. Preparation of Activator and support mixture (not according to the invention): The mixture was prepared by adding separately to the formulation the equivalent amounts of the clay support used in (A) above and the activator and formulated as before.

C. Detergent formulations containing the activators and support: Formulation of the detergents in each case was done exactly in the same manner for all the tests and examples and the following supports were tested at ambient temperature: ASB-60S, ASB-60 and ASB-350 (the latter two are calcium exchanged bentonite, ex English China Clays), kaolinite (Polestar 400, ex English China Clays), acid washed montmorillonite (ex BP International, internal sample), Veegum (ex R T Vanderbilt Co Inc), Hectorite 200M (ex Steetley Minerals, UK).

The conventional detergent formulations in which the above supported activators and mixtures were tested had the following composition (quantities wiw approximate): Surfactants (alkyl benzene sulphonates) 14.76Z Builders (clay and sodium carbonate/sulphate) 53.65% Bleach precursor (sodium perborate tetrahydrate) 20.87% Water 11.32% 5.85g of the above formulation was mixed with 1.0g of 14.3% mixture/supported activator (remainder support). The activator alone (based on all ingredients i.e. the detergent, activator and support) was 2.09%. In each of these cases tested, the amount of activator and support was the same in order to enable strict comparison except that in the case of the Examples according to the invention, the activator was deposited on the support prior to incorporation in the formulation.

Test conditions : The washes were carried out in a Terg-o-tometer over a period of 20 minutes.

Substrate Cloths: EMPA 114 Red wine stain and BCI tea stain Measurements : Reflectance measurements were taken with ICS-Texacan Micromatch spectrometer. Results are expressed as percentage stain removal (%SR) calculated from the following expression: L(final)-L(initial) ZSR = ------------------- x 100 L(standard)-L(final) L(final)= final reflectance value L(initial)= initial reflectance value L(standard)= standard reflectance value L value is reflectance value as defined in Committee Internationale D'Eclarage LAB system (CIELAB).

The results of these experiments are tabulated below: Percent Stain Removal

Stain Examples Comparative Tests 2FB4/ASB-60S (Preformed) 2PB4+ASB-60S (Mixture) TAED+ASB-60S (Mixture) 1 Red Wine 46.9 35.4 35.9 Tea 23.1 14.0 14.2 4M-2PO/ASB60S (Preformed) 4M-2PO+ASB-60S (Mixture) TAED+ASB-60S (Mixture) 2 Red Wine 28.3 21.7 25.9 Tea 8.0 1.3 4.2 2TB-B/ASB-60S (Preformed) 2TB-B+ASB-60S (Mixture) TAED+ASB-60S (Mixture) 3 Red Wine 28.3 21.2 24.9 Tea 5.36 0.24 2.9 2NNDEB/ASB-60S (Preformed) 2NNDEB+ASB-60S (Mixture) TAED+ASB-60S (Mixture) 4 Red Wine* 57.1 52.5 51.4 Tea* 23.5 21.7 19.6 Notes: 2PB4 is 2-phenyl benzoxazin-4-one 4M-2PO is 4,5-dihydro-4-methyl-2-phenyl-[1,3]-oxazin-4-one 2TB-B is 2-tertiary butyl benzoxazin-4-one 2NNDEB is 2-N,N-diethyl benzoxazin-4-one ASB-60S is a type of bentonite * These experiments were done at 40 C; others at 20 C.

Percent Stain Removal

Stain Examples Comparative Tests 20B/ASB-60S (Preformed) 20B+ASB-60S (Mixture) TAED+ASB-60S (Mixture) 5 Red Wine 27.8 23.8 24.9 Tea 8.2 3.9 2.9 SNOBS/ASB-60S (Preformed) SNOBS+ASB-60S 6 Red Wine 26.1 25.1 Tea 4.98 4.35 Notes: Both these experiments were done at 20 C.

20B is 2-octyl benzoxazin-4-one SNOBS is sodium nonanoyl benzene sulphonate The following experiments show the effect of various supports used to form a preformed supported 2PB4 activator and the percentage stain removal observed during wash at 20 C in each case for red wine and tea is tabulated below.

ASB-60 ASB-350 Polestar-400 Montmorillonite* Hectorite Veegum TAED 7 Red Wine 36.1 40.8 38.8 35.8 36.9 33.5 23.9 Tea 14.3 18.0 14.1 12.2 13.8 10.78 2.8 Notes: ASB-60 is a variety of bentonite ASB-350 is a further variety of bentonite Polestar-400 is a kaolinite clay ex English China Clays * The monmorillonite used was acid washed Veegum is the trade name of a clay which is a proprietary product of Steetley Minerals UK Examples using ECE Detergent Base The examples for 2-phenyl benzoxazin-4-one (2PB4) and 2-octyl benzoxazin-4-one (20B4) were repeated using ECE reference detergent base (British Standard BS 1006:C05:1981; ISO-05:C06:1981) according to the following method.

Bleach activator (0.75g) and clay (ASB60S, 4.25g) were weighed into a round bottomed flask. Toluene (6g) and ethanol (18g) were added and heated on a near boiling hot water bath with stirring until the bleach activator had dissolved and dispersed. The solvents were then removed by vacuum distillation on a Bucchi rotary evaporator using a boiling water bath over a 10 minuted period. The residue was removed and ground with a motar and pestle to a fine powder.

This powdered product comprising clay (85%) and bleach activator (15x) was used fresh in the following tests.

All weights in grams

Formulation: ECE base Sodium Perborate Bleach Activator (wt) Support Dose in terg-o-tomater Tetrahydrate 8 8.25 1.5 2PB4/clay (1.67) 0 6.85 C.T.7 8.25 1.5 2PB4 (0.25) 1.42 6.85 9 8.25 1.5 20B4/clay (1.67) 0 6.85 C.T.8 8.25 1.5 20B4 (0.25) 1.42 6.85 C.T.9 8.25 1.5 TAED (0.25) 1.42 6.85 Test Results

8 C.T.7 9 C.T.8 C.T.9 Red Wine (EMPA) 43.69 27.68 30.6 25.29 29.93 Tea 17.99 4.3 8.64 4.23 4.35 Note: C.T. = Comparative Test

Claims

Claims: 1. A composition comprising a perhydrolysable bleach activator releasably deposited on an aluminosilicate support.
2. A composition according to Claim 1 wherein the bleach activator is selected from the group consisting of: tetracetyl ethylene diamine (hereafter "TAED"), sodium nonanoyl benzene sulphonate (hereafter "SNOBS"), sodium iononanoyl benzene sulphonate (hereafter "ISONOBS"), a cyclic anhydride of the formula (I), a lactone of the formula, (II),

a compound of the formula Rl-Co-N(R5)-R2-Co-L (III) and a compound of the formula R1-N(R5)-CO-R2-CO-L (IV) wherein: a) the notations Q in formulae (I) and (II) represent a divalent organic grouping such that Q and N together with the carbonyl and oxygen functions form one or more cyclic structures and in (I) R is H, an alkyl, aryl, halogen, a carboxylic or a carbonyl containing function, and in (Il) R is a C2 or higher alkyl, alkaryl, aralkyl, alkoxyl, haloalkyl, alkylamino, dialkylamino, carboxylic or a carbonyl-containing function; b) in formulae (III) and (IV) R1 is an alkyl, aryl, alkyloxy or an aryoxy group, R2 is an alkylene or an arylene group, R5 is H, an alkyl, aryl, halogen, a carboxylic or a carbonyl containing function, and L is a leaving group such that when the bleach activator is in an aqueous alkaline medium and in the presence of a bleach precursor capable of giving rise to a peroxy compound in an aqueous medium* the compounds (III) and (IV) are transformed into the corresponding percarboxylic acids.
3. A composition according to Claim 1 ro 2 wherein the bleach activator is selected from the group consisting of: a) isatoic anhydride; b) 2-alkyl-, 2-aryl- and 2-dialkylamino derivatives of 3,1(4H)-benzoxazin-4-one; c) N-lauroylamino caproic acid, 6-decylamino-6-oxo caproic acid and 6-benzoylamino caproic acid.
4. A composition according to any one of the preceding Claims wherein the aluminosilicate support is a crystalline or amorphous zeolite or a clay.
5. A composition according to any one of the preceding Claims wherein the support is selected from the group consisting of bentonite clay, montmorillonite, kaolinite, hectorite, Veegum and Wesselith P.
6. A composition according to any one of the preceding Claims wherein the support is a clay which has a lattice-type structure.
7. A composition according to any one of the preceding Claims wherein the amount of bleach activator deposited on the support is from 5-95% w/w of the total including the support
8. A composition according to any one of the preceding Claims wherein the supported bleach activator has an average particle size in the range from 35-420 micrometers.
9. A detergent formulation comprising: a) a surfactant selected from anionic, nonionic, zwitterionic surfactants and mixtures thereof, b) a precursor compound capable of giving rise to a peroxygen compound in the presence of water, c) a bleach activator capable of enhancing the bleaching activity of the peroxygen compound so formed, d) a suds suppressing agent and d) a detergent builder, characterised in that the bleach activator is releasable deposited on an aluminosilicate support as claimed in any one of the preceding Claims prior to incorporation thereof in said formulation.
10. A detergent formulation according to Claim 8 wherein the bleach activator is a 2-substituted 3,1(4H) benzoxazin-4-one in which the 2-position is substituted either directly or through a hetero atom by a hydrocarbyl group containing at least 3 carbon atoms.
11. A detergent formulation according to Claim 8 wherein the bleach activator is a cyclic anhydride of isatoic anhydride type in which the 5- or 6- position is substituted either directly or through a heteroatom by a hydrocarbyl group which contains at least 3 carbon atoms.