CA1316790C

CA1316790C - Non-phosphorus detergent bleach compositions

Info

Publication number: CA1316790C
Application number: CA000580630A
Authority: CA
Inventors: William D. Emery; Stephen G. Barnes; Peter S. Sims
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1987-10-23
Filing date: 1988-10-19
Publication date: 1993-04-27
Anticipated expiration: 2010-04-27
Also published as: JPH01146997A; NO884700L; BR8805450A; EP0313144A2; KR920002085B1; KR890006803A; AU612711B2; GB8724900D0; NO884700D0; EP0313144A3; AU2400788A

Abstract

ABSTRACT

Non-phosphorus aluminosilicate built detergent bleach composition having really effective cleaning and stain removal performances at low wash temperatures of 40°C and below, comprising at least one detergent-active material selected from anionic, nonionic, amphoteric, zwitterionic detergent compounds and soaps and mixtures thereof, and (a) from about 15% to about 40% by weight of a water-insoluble aluminosilicate cation-exchange material;
(b) from about 1% to about 15% by weight of citric acid or an alkali metal citrate;
(c) from about 5% to about 35% by weight of an inorganic peroxide compound; and (d) from about 1% to about 10% by weight of a peroxybenzoic acid bleach precursor.

Description

13~7~
1 C 7106 (R) MON-PHOSPHORUS DETERGENT BLEACH COMPOSITIONS

This invention relates to non-pho~phoru~ detergent bleach compositions. In particular it rela~es to aluminosilicate built laundry detergent bleach compositions having improved cleaning and stain-removal performances.

The role and value of phosphate deter~ency builders in laundry detergent composition~ are well-known. In recent ~_ years, however, the use of phosphate builders, such ac the alkali metal triphosphates, has come under scrutiny because of the suspicion that soluble phosphzte species accelerate the eutrophication of water bodies. In a number of countries phosphate legislations have already ~orced detergent manufac-turers to radically reduce the phosphate level of detergent compositions down to substantially zero. The need exists, therefore, for a built laundry detergent composition with zero or reduced phosphate levels but which i8 comparable to a conventional triphosphate built composition in overall detergency effectiveness.

Furthermore, with the present trend to lower fabric washing temperatures, there is an incentive to improve on the formulations of detergent compo~itions so as to be ef~ectlve at lower washing temperatures of e.g. 40C and below.

Water-insoluble aluminosilicates, commonly known as zeolites, have been usQd in detergent compo~itions a~ important alternative builders to phosphates (~ee, for example, GB-A-1429143; GB-A-1470250; GB-A-1504211; GB-A-1529454 and US-A-4064062). Bleaching experiments have indicated, however, that the bleach performances of aluminosilicate built formulations are well below thcse of phosphate built products.

7 ~ ~

2 C 7106 (~

In EP-8-0001853 aluminosilicate built detergent compo6itions are disclosed which contain 0.01-4~ by weight o~ a polyphosphonate sequestering agent and 5-25% by weight of citri~ acid or citrates as pH-regulating agent. These compo~itions are unsatis~actory when used for washing at the low wash temperature region of 40C and below.

It is an object oP the pre~ent invention to provide an improved aluminosilicate built detergent compoaition having really effective cleaning and stain-removal per~ormances at low wash temperatures of 40C and below.
-It has now been found that the above object can be achievedby having incorporated therein an inorganic peroxide compound and a peroxybenzoic acid bleach precur~or as the principal bleach system together with citric acid or an alkali metal citrate.

Thus, accordin~ to the invention, there is provided a non-phosphorus detergent bleach composition comprising at least one detergent-active material and :
(a) from about 15% to about 40% by weight of a water-insoluble aluminosilicate cation-exchange.material;
(b) from about 1% to about 15% by weight of citric acid or an alkali metal citrate;
(c) from about 5% to about 35% by weight of an inorganic peroxide compound; and (d) from about 1% to about 10% of a peroxybenzoic acid bleach precursor.
The detergent composition of the invention necessarily contains a peroxybenzoic acid bleach precursor as the bleach activator, which on perhydrolysis generate~ a peroxybenzoic acid. Other bleach precursors, such as the most commonly u~ed tetraacetylene diamine (TAED), which generates perac~tic acid, are much less effective and hence unsuitable for use in 1 3 ~ ~ ~ J I~

3 c 7106 ~R) the present invention.

Peroxybenzoic acid precur~ors are known in the art, e.g. from GB-A~836988. Examples thereof are phenylbenzoate; phenyl p nitrobenzoate; o-nitroph~nyl benzoate; o-carboxyphenyl benzoate; p bromophenyl benzoate; sodium or potassium benzoyloxybenzenesulphonate; and benzoic anhydride.

The compounds have the general formula :
1 0 ~ O
~ 0 >-~-L
wherein R i~ ~ a substituent selected from -N02 and halogens, and L i~ a leaving group, the con~ugate acid of which has a pKa in the range of from about 6 to about 13.
L can be essentLally any ~uitable leaving group that is displaced from the bleach precursor as a consequence of the nucleophilic attack on the bleach precursor by the perhydroxide anion, H00-. ~hi~ perhydroly~i~ reaction results in the formation of the peroxybenzoic acid. Generally, for a group to be a suitable leaving group, it must exert an electron-attracting effect, which facllitAte~ the nuclaophilic attack by the perhydroxide anion. Leaving groups that exhibit such behaviour are those in which their con~ugate acid has a pKa in the range of from 6 to 13, preferably from about 7 to about 11, and most preferably from 8 to ll.

Example~ of suitable L are :
RlY ~__VR2 0 -0- ~ ; -0- ~ ; -N-C-R3 ~ 3 ~ ~ 7 ~f~

4 5 7106 (R) O O
-o-C-R3 ;~ CH2 ~ C ~
-N ~ ~ NH
C
o -O--CH=C--CH=CH2 , --O--C=CHR

wherein Rl i~ an alkylene chain containing from 1 to 8 carbon atoms; R2 is H or an alkyl chain containing from 1 to 8 ~_ carbon atoms; R3 is phenyl or an alkyl chain containing from 5 to 18 carbon atoms; and Y is a solubilizing group, preferably selected from -S03-M+, -C00-M~ or -S04-M~.
A preferred peroxybenzoic acid bleach precursor i8 sodium p-benzoyloxybenzene sulphonate of the formula :

~ -C - 0 - ~ -S03Na The inorganic peroxide compounds usable in the present invention can be true persalt~ or perhydrates, which liberate hydrogen peroxide in aqueous solution. Examples or inorganic peroxide compounds are the alkali metal perborates, percarbonates, and persilicates, the perborates, particularly sodium perborate tetra- and monohydrate being preferred because of their commercial availability.

Within the above ranges of weight percentages the inorganic peroxide compound and the peroxybenzoic acid bleach precursor in the composition of the invention may be pre6ent in a molar ratio of between 0.5:1 and about 20:1, pre~erably from 1:1 to 10:1. Under certain wash conditions a molar ratio of about 2:1 may be of advantage.

7 ~
C 7106 (R) The composition of the invention contain~ at least one detergent-active material which can be an organic ~oap or synthetic detergent surfactant material. Generally, from about 5% to 40% by weight of an organic, anionic, nonionic, amphoteric or zwitterionic detergent compound, soap, or mixtures thereof 18 included. Many suitable detergent-active compounds are com~ercially available and are fully described in literature, for example in US-A-4222905 and US-A-4239659 and in "Surface Active Agents and Detergents", Vol. I and II, by Schwartz, Perry and Berch.

The preferred detergent-active compounds which can be used are synthetic anionic, soap and nonionic compounds. The first-mentioned are usually water-soluble alkall metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher aryl radicals. Exa~ples of suitable synthetic, anionic detergent compounds are sodiu~ and potassium alkyl sulphates, ospecia-lly those obtained by sulphating higher (C8-C18) alcohols produced, for example, from tallow or coconut oil; sodium and potassium alkyl (Cg-C20) benzene sulphonates, particularly 80dium linear secondary alkyl (ClO-c15) benzene sulphonates;
_ sodium alkyl glyceryl ether sulphates, especially those esters of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petrolaum; sodium coconut oil fatty acid monoglyceride sulphates and sulphonates; sodium and potassium salts of sulphuric acid esters of higher (Cg-Cl8) fatty alcohol-alkylene oxide, particularly ethylene oxide, reaction products; the reaction products of fatty acids such as coconut fatty acids esterified with i~ethionic acid and neutralized with ~odium hydroxide; sodium and potas ium salts of ~atty acid amides of methyl taurine; alkane monosulphates such as those derived by reacting alpha-olefins (C8-C2Q) with sodium bisulphate and those derived by reacting paraffins with S02 and C12 and then 1 3 ~

6 c 7106 (~) hydrolyzing with a base to produce a random culphonate:
olefin sulphonates, which term is used to describe the material made by reacting olefins, particularly C10-C2~
alpha-olefins, with S03 and then n~utralizing and hydrolyzing the reaction product. Suitable soaps are the alkali metal salts of long chain C8-C22 fatty acids such a~ the sodium soap~ of tallow, coconut oil, palmkernel oil, palm oil or hardened rapeseed oil fatty acid or mixture~ thereof. The preferred anionic detergent compounds are ~odium (Cll-C
lo alkyl benzene sulphonate3 and sodium (C16-C18) alkyl sulphates.
.~
Examples of suitable nonionic detergent compounds which may be used include the reaction products of alkylene oxides, usually ethylene oxide, with alkyl (C6-C22) phenol~, genera-lly 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule; the condensation products of aliphatic (C8-C183 primary or secondary linear or branched alcohols with ethylene oxide, generally 6 to 30 EO, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylene diamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxide~, long chain tertiary phosphine oxides and dialkyl sulphoxide6.
Mixtures of detergent-active compounds, ~or example mixed anionic or mixed anionic and nonionic compounds, may be used in the detergent compositions, particularly in the latter case to provide controlled low sudsing properties. This i8 beneficial for compositions intended for use in suds-intolerant automatic waRhing machine6.

Amounts of amphoteric or zwitterionic detergent-active compounds can also be u~ed in the co~position~ of th~
~5 invention, but this i8 not normally desired owing to their relatively high cost. If any amphoteric or zwitterionic, ~ 3 ~ ~ d3 v~

7 C 7106 (R) detergent-active compoundg are u ed, it i8 generally in emall amounts in the compo~itions based on the ~uch more commonly used ~ynthetic anionic and/or nonionic detergent-active compounds.
The detergent composition o~ the invention al80 contain~ a water-insoluble aluminosilicate cation-exchange material in an amount of from 15% to about 40% by weight, preferably from 20% to 35~ by weight.
The aluminosilicate can be crystalline or amorphous in character, preferred materials having the unit cell formula I

Mz [(AlO2)Z (SiO2)y] xH2O
wherein M is a calcium-exchange cation, z and y are at least 6: the molar ratio of z to y is from about 1.0 to about 0.5 snd x 16 at least 5, preferably from about 7.5 to a~out 276, more preferably from about 10 to about 26~. ~he aluminosilic-at~ materials are in hydrated form and are preferablycrystalline containing from about 10% to about 28%, more pre~erably from about 18% to about 22% water.

The aluminosilicate ion-exchange material~ are further characterized by a particle size diameter of from about 0.1 micron to about lO microns, preferably from about 0.2 micron to about 4 microns. The term "partlcle size diameter" herein repre~ents the average part~cle size diameter of a given ion-exchange material as determined by conventional analytical techniques uch as, for example, microscopic determination utilizing a ~canning electron microocope. The aluminosilicate ion-exchange materials herein are usually further characteri-zed by their calcium ion-exchange capacity, which is at least about 200 mg. equivalent of CaCO3 water hardness/g of aluminosilicate, calculated on an anhydrous basis/ and which generally is in the range Or from about 300 mg eq./g to about 1 3 ~

8 C 7106 (R) 352 mg eq./g. The aluminosilicate ion- exchange materials herein are still further characterized by their calciu~ ion-exchange rate which i~ at least about 2 grain~ Ca~+/gallon/
minute/gallon of alumino~ilicate (anhydrou~ ba~is), and generally lie~ within the range of from about 2 grain~/
gallon/minute/gram/gallon to about 6 grain~/gallon/minute/
gram/gallon, based on calcium ion hardness. Optimum aluminosilicates for builder purposes exhibit a calcium ion-exchange rate of at least about 4 grains/gallon/minute/gram/
lo gallon.

~- Aluminosilicate ion-exchange materials useful in the practice of thi~ invention are commercially available and can be naturally occurring aluminosilicates or synthetically derived. A method for producing aluminosilicate ion-exchange materials is discussed in US-A-3985669. Preferred synthstic crystalline aluminosilicate ion-exchange materials useful herein are available under the designations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion-exchange material is Zeolite A and has the formula Nal2[Al02)12 (SiO2)12] X~2 wherein x is from about 20 to about 30, especially about 27.
Zeolite X of formula Na86 [(Al2)86)(si2)l06] 276 H20 i~
also suitable, as well as Zeolite HS of formula Na6 ~(Al02)6 tsi2)6] 7-5 H20)-30The detergent composition of the invention further contains an alkali metal citrate or citric acid in an amount of from about 1% to about 15%, preferably from 2 to 10%, by weight of the composition. A preferred alkali metal citrate i8 sodium citrate, particularly trissdium citrate, i.e.
CSH507 Na3 2H2 -13 ~ 6 ~

9 C 7106 (R) Apart from the component~ already menti~ned, the detergent compo~ition herein can contain any of the conventional additive~ and adjuncte in the amounts in which ~uch materials are normally employed in ~abric washing compositions.
Examples of ~uch additives include lather boo~ters ~uch as alkanolamides, particularly the monoethanolamides derived from palmkernel and coconut fatty acid~; lather depre~sants such as alkyl phosphates, silicones and waxes; anti-redeposition agents such as sodium carboxymethyl cellulose (SCMC), polyvinyl pyrrolidone (PVP) and the cellulose ethers, such as methyl¢ellulose and ethyl hydroxyethyl cellulose;
_ stabilizers such as ethylene diamine tetraacetate3 fabric softening agents inorganic salts such as sodium sulphate and sodium carbonate: and - usually pre~ent in very minor amounts - fluorescent agents, perfume~, enzymes such as proteases, amylas~s and lipases: germicides and colourants.

Polycarboxylate polymers, though not es~ential, may also be included as desired in amounts of e.g. from about 0.5% to 6%
by weight of the total composition. The polycarboxylate polymer6 herein are preferably selected from co-polymeric polycarboxylic acids and their ~alts derived from an unsaturated polycarboxylic acid ~uch as maleic acid, citraconic acid, itaconic acid or mesaconic acid as a first monomer and ethylene, methyl vinyl sther, acrylic acid or metacrylic acid as a second monomer, the co-polymer comprising at least about 10 mole%, preferably at least about 20 mole% of polycarboxylic acid units and having weight average molecular weight~ of at lea~t about 10,000, preferably at least about 30,000; homopolyacrylates and homopolymethacrylates having a weight average molecular weight of from about 1000 to about 100,000, preferably from about 5000 to about 50,000; and mixtures thereof.

The detergent blea¢h compositions of the invention are alkaline and will advantageou~ly have a solution pH (2-10 ~ 3 ~ 0 C 7106 (R) g/l) of from 8-11, with an optimal pH of between 8 and 9. A
wash pH of, say, 8.5 appears to give the best compromise for achieving good bleaching, detergency and enzymatic soil removal. In order to adjust the p~, buffering agents, such as horax, may be necessary.

~he detergent compositions of ~he invention are preferably presented in free-flowing particulate, e.g. powdered or granular form, and can be produced by any of the known techniques commonly employed in the manufacture of such washing compositions, but preferably by spray-drying an aqueous slurry comprising the surfactant(s), the alumino-silicate and the alkali metal citrate to form a detergent base powder, to which the heat-sensitive ingredients, including the peroxybenzoic acid bleach precursor, the inorganic percompound, enzymes and optionally some other ingredients as conveniently desirable are added.
Alternatively, the alkali metal citrate can be separately dry-mixed with the spray-dried base powder. The bleach precursor and enzymes are preferably added as granulated particle6. It i8 preferred that the process used to form the compositions should result in a product having a moisture content of up to about 15%, more preferably from about 7% to about 14% by weight.
The invention will now be illustrated by the following non-limiting Examples.

1 3 ~
11 C 7106 (R) Example ~

The following particulate non-phosphate detergent compo~ition was prepared by spray-drying an aqueous detergent slurry to form a detergent base powder composition (A~ which iB
combined with a particulate product composition (B).

Composition A P~rts by weiah~
Sodium linear alkylbenzene ~ulphonate 9.0 10 Fatty alcohol-7 ethoxylate 1.5 Maleic acid/acrylic acid copolymer ~- (Sokalan ~ CP5 ex BA~,F) 4.0 Sodium aluminosilicate (Zeolite A) 24.0 Sodium sulphate (anhydrous) 0.3 15 Sodium carboxymethyl cellulo~e0.5 Sodium ethylenediamine tetraacetate (ED~A) 0.2 Sodium carbonate ~Na2C03) 2.0 Water and fluorescer (0.13) 7.6 20 Composition ~B) Sodium perborate monohydrate13.0 Anti-foaming agent 2.5 Proteolytic enzyme (Savinase ~ ex NOV0) 0.5 Sodium p-benzoyloxy benzene ~ulphonate 5.0 25 Sodium sulphate 29.9 Washing experiments were carried out with this combined composition without and with added trisodium citrate at levels of 0%, 1%, 2%, 3%, 5%, 10% b~ weight in 30 minutes' Tergotom~ter washe~ using a do~age o~ 8 gram/litre in 240FH
water at 40C, buffered at pH 8.5.

The bleaching properties on tea and red-win~ stains wers mea~ured; the results are given in ~able I.

1 3 ~
12 C 7106 (R) Table I
~R v~
Tea wine Composition A/s + 0% ~itrate 6.4 20.1 " + 1% citrate 8.2 26.3 + 2% citrate 9.6 29.9 ~' + 3% citrate 11.7 32.0 lo ~ ~ s% citrate 13.2 33.9 " + 10% citrate 14.4 35.7 , Example ~

Similar comparative experiments were carried out on tea and red-wine stains, detergency and protein ~tain removal (enzyme action); the results are shown in Table 2.

TAB~E 2 ~ R-v~lues Tea Wine Deter- Protein gency ~tains Composition A/B + 0% citrate 8.1 24.5 25.6 34.2 ~~ 25" + 5% citrate 13.8 32.6 26.3 34.8 From the above results it can be seen that trisodium citrate boosts the bleach performances on tea and wine stains without a negative effect on detergency and enzyme action, i.e.
protein fioil removal.

Claims

1. A non-phosphorus detergent bleach composition comprising at least one detergent-active material and (a) from about 15% to 40% by weight of a water-insoluble aluminosilicate cation-exchange material;
(b) from about 1% to 15% by weight of citric acid or an alkali metal citrate;
(c) from about 5% to 35% by weight of an inorganic peroxide compound; and (d) from about 1% to 10% by weight of a peroxybenzoic acid bleach precursor.

2. A composition according to Claim 1, comprising :
- from 5 to 40% by weight of said detergent-active material selected from the group consisting of anionic, nonionic, amphoteric, zwitterionic detergent compounds, and soaps and mixtures thereof;
- from 20 to 35% by weight of said aluminosilicate cation-exchange material; and - from 2 to 10% by weight of said citric acid or alkali metal citrate.

3. A composition according to Claim 1, wherein said peroxybenzoic acid precursor is sodium-p-benzoyloxybenzene sulphonate of the formula :

4. A composition according to Claim 1, wherein said alkali metal citrate is trisodium citrate.

5. A composition according to Claim 1, wherein said composition has a solution pH (at 2-10 g/l) of 8-11.

6. A composition according to Claim 5, wherein said solution pH is between 8 and 9.