CA2252497A1 - Alkaline peroxide liquid detergent composition - Google Patents

Abstract

Use of an alkali metal perborate or percarbonate salt as a buffering additive in the manufacture of an alkaline peroxide-containing liquid detergent composition, characterised in that the level of the persalt added, based on peroxide equivalent content, is less than 90 %, preferably less than 75 %, most preferably less than half of the total peroxide equivalent in the composition. Also a method of cleaning laundry comprising the direct application to the laundry or a selected part of the laundry of a composition according to any one of claims 5 to 8, optionally followed by a rubbing action.

Description

CA 022s2497 1998-10-16 ~T.TCAT.TNE PEROXrDE LIOUnn DETF.T~GE~rr CO~IPOSITION

This invention relates to alkaline pe~o~ide liquid detergent compositions for fabric washing.

To obtain effective de~ y from an alkaline liquid d~ composition across a range of use cnnAihnnc it needs to be buffered. Borax and sesquicarbonate are frequently incorporated into liquid det~ ent form~llq~innc Both help to ~ *; a high wash liquor pH We have found that each of these mqt~?riqle is incompqh~le with hydrogen peroxide.
10 Sesquicarbonate gives the required bl~ff~-rinE but it also gives rise to rapid decomposition of peroxide. Borax gives lower, but stiU lm cceptqbly high, levels of peroxide deco~osition.

Many publicqti~nc mention the possibility of nd~litinn of a persalt such as ~ I,ora~e or 15 percarbonate to an ~lk~lme detergent liquid. Usually it is sn~g~sted as a repl-q-c~mrnt for hydrogen peroxide which is the ~ f~,.r~,d form of yclu~ide. Tfit were to be used in this way then there would be solid persalt present in the composition. Such a use is descll~cd in EP-A-294 904 describing the fo....~ of sllcren~le~l sodium pc~l,olale cIystals by recrystallisation. There w~l be a minor amount of hydrogen peroxide and dissolved persalt in e~ ,. ;.. with the re~,~y~l ~lliced perborate held in slls[~n~ -n The reference teaches that this should be ...;..;...;~eA by use of a water miscible organic solvent to reduce the solllbil;ty of the p~,ll.ora~e i~ the liquid phase.

2 ~isrlose~C general ~ ose alkaline blea~ ing or .~ .r~ ~;.,g compûsitions co..~ lessthan 1% of optional amine oxide s~lrf~ nt, 0.5%borax, and 5 or 10%
Lùg~ peroxide, The pH of the formlll~tinnc tested is ~lcted with sodium hydroxide to the relatively low initial value of 8. 5 and the 12 week stability data for the 5% hydrogen peroxide forrmllptit)n with'out any sllrf~ nt stored at about 30~C shows low loss of ~, ~ ~.

peroxide, but it is clear that the b~ffenng is not ~qdeqllqte because the pH drops. There is no sll~çs~ion to use anything other than disodium tetraborate decahydrate (borax) as the bui~er.

WO 93/01270 discloses an alkaline aqueous liquid washing agent cO.. ~ ; ,g s~lrf~ctq~ t hydrogen peroxide and a water soluble borate chosen from borax and sodium borate, the mole ratio of peroxide: borate being greater than 1.5:1 and the composition having an initial pH of less than 8 in all the examples. The invention resides m the ability of the water soluble borate and other ingredients to give a pH rise to about 9 when the composition is 10 diluted. All form-llqtinn~ contain solvents such as ethanol and propylene glycol. Sodium perborate is not used or ~l~çste(l There is no disclosure or 5~l~g~ ;nll in the prior art that a mmor amount of persalt can be used in solution to bu~er a liquid Ch .~ hydrogen peroxide m solntinn According to the present invention there is provided use of an alkali metal perborate or percarbonate salt as a buffering additive in the mqT-lf~ re of an alkalme peroxide-c~.-- ~;..;..~ liquid d~ h~ composition, charactPn~ed in that the level of the persalt added, based on p~ ide equivalent content, is less than 90%, preferably less than 75% and most 20 preferably less than half of the total peroxide equi~alent in the composition.

Preferably the bnff~nn~ additive is dissolved ill the li~uid ~ .L composition as this avoids the y~ tn of 5~ ; g a solid co~one~l. This is e~e~iqlly advantageous if the composition is isulloyi The best combination of bllffPnng and peroxide stability is obt-q~ ed when the buffering additive is pell,o,ale, preferably sodium p~,~l,olale tetrahydrate or monohydrate.

Acc~d;..g to a second aspect ofthe present invention there is provided an alkal~ne peroxide , . ............ .

d detprgent cGllyO~ùlc~ g~lrf~Ctqnt~ a peroxygen bleach and a soluble buffer, characterised in that the peroxygen bleach is hydrogen peroxide and the buf~er is an inorganic persalt selected from alkali metal or alkaline earth salts of perborate and p~,..,~l,o~ate, wherein the available oxygen from the hydrogen pe,ox~de eYcee-ls that from 5 the persalt, plef.,.~bly by at least 2:1 and most preferably by at least 3:1.

~nrfac~t~ntc Compositions of the present invention cc,~lise 5-60% by weight sllrf~ct~ntc Peroxide 10 reacts with many sllrf~~t~tc to give reaction products which cause a lowering of the composition pH By using the buffers of the present invention a wide range of s~lrf~ct~ntc, which may be s~lected from anionic, cationic7 nnniQni~ zwttPrinni~ and amphoteric cllrf~ct~ntc and blends thereof, may be used. For example, they _ay be chosen from any ofthe classes, sub-classes and specific mqtPriqlc desc.;l,ed in "Surface Active Agents" VoL
15 I, by Schwartz & Perry, Interscience 1949 and "Surface Active Agents" Vol. II by Schwartz, Perry & Berch (lnterscience 1958), or in "McCutcheon's Fm~lcifiPrS &
Detergents" pub}ished by the McCulclleon drvi~on of M~n-lfa~lring ConfP~inn~rs Co~any or in Tensid-Taschenbuch", ~ Stache, 2nd Edn., Carl Hanser Verlag, Mlm~hPn &VVlen, 1981.
Suitable nn- inniç s~lrf~çtant~ inr~ e~ in p~ticular, the reaction products of coi~.you~ds having a hydrophobic group and a reactive hydrogen atom, for P ~ ~"~ kp-L~he alcohols, acids, amides or alkyl phenols with alkylene oxides, espe~qlly ethylene oxide either alone orwithpropylene oxide. Spe~ifie nonionic detergent co~uullds are alkyl (C~l8) primaIy 25 or secondary linear or branched ~ L-,Ic with ethylene oxide, and products made by cond~nc~tion of ethylene oxide with the reaction products of propylene oxide andethyl~ ~-e l;~ e Other so-called nnniQnir. detergent co~i~uuilds include long chain terhaIy amine oxides, long chain ter~ary phûsphine oxides and dialkyl sulphoxides.

Alco possible is the use of salting out ~e~l~t active nlqtPliqls such as des~i~ibcd in EP 328 117, especially the use of alkyl poly glycoside s~rfqctqnt.c such as disclosed in EP 70 0~4.

Su~able anionic ~ -- r;~ e are usually water-soluble alkali metal salts of organic slllrhqtPs 5 and sulphonates having alkyl radicals cr...~i.;..;..~ from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. F.~iln~rles of suitable synthetic anionic detergent compounds are sodium and potassium . lkyl elllph~tPc Pepe~qlly those obtained by sll1rhqting higher (C8-~8) alcohols produced for example from tallow or coconut oil, sodium and ~.~las~ alkyl (C9-20) be~enc slllrhclnP~PC particul. rly 10 sodium linear secondary alkyl (C~0-,5) b~ e sl~lrhonq-tes; sodium alkyl glyceryl ether sulphates, P~re~qlly those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium coconut oil fatty monoglyceride c llrhqtçs and ~ h~ t~--;, sodmm and ~olas~ salts of sulphuric acid esters of higher (C8-18) fatty alcohol-alkylene oxide, particularly ethylene oxide, reaction products; the reaction 15 products of fatty acids such as coconut fatty acids ectPrifiPd with icethionic acid and neutralised with sodium hydroxide; sodium and potqcrnlm salts of fatty acids amides of methyl ta mne; aLane mr noSlllrh~nqtpc such as those derived by reacting alpha olefins (C8-20) with sodium bicl~lph*e and those derived from reacting paraffins with SO2 and Cl 2 and then hydrolysing with a base to produce a random s~l~rh( n~te; and olefin ~-lrhonqt~Pc~ which 20 term is used to descnbe the mqtPriql made by r~z~ ole_ns, particularly Cl0-20 alpha-olef~s, u~ith SO3 and then neutralising and hydrolysing the reaction product. The p~ d aluonic det~g~t co~ o~ le are sodium (Cll-l5) alkyl b~ rSIllpl'~mq-teS and derivatives of amino acids, such as oleyl sarcosinates, may also be used.

25 It is also possible to include an alkali metal soap of a fatty acid, eere~iqlly a soap of an acid avmg from 12 to 18 carbon atoms, for eYqmplP, oleic acid, ricinoleic acid, and fatty acids derived from castor oil, alkyl~c~ acid"~peseed oil, groundnut oil, coconut oil, pqlmkPmPI oil or ~lu~es thereof. The sodium or potassium soaps of these acids can be used.

The total detergent active mqt~nql may be present at from 0. 5% to 60% by weight of the total composition, for example from 1% to 40% and typically from 2% to 20% by weight.
- However, one pl~fell~d class of compositions compric~Ps from 3-12% of detergent active material based on the weight ofthe total co~o~io~ The actual amount of sll~fq-ct-q-nt used 5 w~l depend on the ~pli ~ n, a hard surface cleaner will have a low amount, a fabric pre-treatment composition a rather higher amount and a concentrated detergent a high amount.

Optional T~, ~L~ls 10 Compositions of the invention may be isotropic (unstIuctured) or structured. Structured liquids ofthe invention may be intp~qlly structured whereby the stIucture is formed by the detergent active mqtPnole in the composition or exte~nally structured. F~-f~ublycompositions of the invention are iSOll'OpiC.

15 VlSCoSl~y may be ~ 1 by use of one or more h~d~ol~opcs. It is pref~lled to avoid use of l,2diols.

Compositions of the invention may also co...l,. ;ee mqtPriqlc for a~leting the p~ For lowenng the pH it is pn~ d to use weak acids, e~er;qlly organic acids, most pl~ ,d 20 is the use of Cl~ carboxylic acids, the pl~f~lled carboxylic acid is CitIiC acid. The use of these pH lowering agents is ee~e~ally prefe.l~,d when the co~o~L;~s of the invention ca~ain enz~,rmes such as ...ylasei, pl~C ~ S and l~ola~s. For raising the pH it is plef~ ,d to use sodium hydroxide, preferably pre-sequestered.

25 Apart from the ..,~,L,~LS already ... 1;~ P~1 a llumbcr of other optional ing~ may also be present at levels below 5%, for ~A~le lather boosters such as alkanola-mi~l~e particularly the monoethanr~lamides derived from palm kernel fatty acids and cocomlt fatty acids, fabric sofLeners such as clays, amines and amine oxides, lather d~ss~ls, s~ds regulators, inorganic salts, and, usually present in very minor amounts, op3~ifiP~s~

... . . .... . . ..

~o.~ ~ agents, and optical brighteners, pPrfilm~c, germ~ s, colorants and dyes, and enzymes and enzymatic stabilising agents.

Other additives that may be incorporated are soil release agents such as Carbo~~ ~yl 5 c~lh~l~ sç, also known as anti-redeposition agents; dye transfer mhih~nE polymers such as polyvinylpyrrolidone and optical br-&htPnmE additives (OBAs) such as distyryl b;~yl denvatives.

Cc~o~ns of the invention preferably co...l.. ;.ce from 10-93% by weight of water, more preferably from 15-90%, most prefefably from 40-88%.

Co~o~ion s ofthe present invention may col.,pllse one or more bleach ~.~ eulsor agents.
A well-known example of such an agent is TAED. ~ef~,.ably the bleach p~ or agentis present in the system in at least partly lm~ solved for~
In use the ~letP~nt compositions of the invention will be diluted with wash water to form a wash liquor for instance for use in a washing -~hine The cnn~Pntration of liquid d~L~ L composition in the wash liquor is preferably from 0.05 to 10%, more p~eîel~ d from 0.1 to 3% by weight. The co.~'1'~~ ns can also be applied neat to a soiled g~....l ..l 20 as a pre-h~" h.. ~ The b ~ff~me makes them particularly beneficial for such use becrll~e they retain alkal~ in storage and use: and have a higher ~let~.g~r,y against oily stains than an ~...~..-~r. -~.d or acid liquid. Hard surface cleaners and general ~ ose r.~ rs are also used neat; but may be diluted if ~ d.

25 Bni~ rs The present compositions may contain a builder, pfeîe.ably at a level no more than 50%, more preferably at a level of from 5% to 40% of the total composition.

... . . -- .

lf present, such builders can consist of inorg~nic or organic types, organic builders are p~ ed.

The liquid dete~ t compositions herein optionally may cc-nt~in as a builder, a fatty acid CG ~olle.-t. P~efe.~bly, however, the amount of fatty acid is less than 10% by weight of the co~po~ion, more preferably less than 4%. P~.,fc,led saturated fatty acids have from 10 to 16, more p~e~e.ably 12 to 14 carbon atoms. F'~rtll~d 1m~ ed fatty acids are oleic acid and palmitoleic acid.

10 Examples of organic builders are polyacids such as citric acid, nitrilol ~-eti~ acid, and llfi~ es of tartrate monos 1crn~te with tartrate ~ic~lc~te I~. fell~ d builders for use heranareCitIiCacidandCl0.16alk(en)y-l-a~ e~ls~c~i~acidco.~ u~ds. Ane~ le ofthis group of c-,...l.u~ ~lc is do~ nyl succinic acid. Polymeric carboxylate builders such as polyacrylates, polyhydroxy acrylates and polyacrylates/polym71~tes copolymers can also be used.

Sequestr~ntc The compositions herein may also contain other components and/or additives at a level 20 preferably less than about 5%. Non-limiting ~,~ rl ~s of such add*ives, which can more preferably be used at levels from 0.03% to 2%, include poly~min~ca~boxylate additives suchasethy1~ P~ inotetraceticacid,diethyl-~ I-h;~ ino-p~nt cetiCacid,ethylene~ -o r~ir acid or the water soluble alkali metals thereo~ Other add*ives useful at these levels include organo-pho~ph~ni~ acids; particularly pr~f~ ,d are ethylf ~PAi-~-~mo 25 t~L~- elllylenephospholuc acid, diethy1r~c~ . ,no ~ .y1f~nsphosp~ nic acid amino~imethy1~ne~hosphnnic acid, and hydroxyethylidene diphos~honil~- acid. Bleach stabilisers such as dipicolinic acid, sodium ct~nn~teS and 8-hydroxyqnino~in~o can also be included in these cu~o~hions at these levels, ~l~,f~ably at levels from between 0.0l to 1%.

pqrh~llq~ly yl~;Ç~ d combinqtinnc of sequestrants are disclosed in PCT/GB95/01537 and comprise sodium diethylene triamine pen~a(methylene phosphonate) such as is sold as Dequest 2066 by ~ nQq-lto (and referred to hereinaflter as D2066) and 2,2'-dipyridylamme (hereinafter l~f~.l, d to as DPA) and D2066 and 1,2-~liqminncyclohexyl tetra (methylene 5 phosphonic acid) and salts thereof (hereina~er l~r~ d to as DACH).

The combination of seqllPctpring agents gives a universal seqlleet~ng p~ r(~ e on trqn~inn metal ions. In general these can be separated into two groups, Group A and Group B.
The Group A seque~et~ing agent preferably cn..~l.. .ses one or a mixture of more than one seqneste~ng agents which is effective for ~labili~g peroxide against decomposition by cobalt II ions under alkaline c~ -~itinnc They may also be effective for sequestP~ing the other t q l~inn metal ions. The Group B seqllest~nn~ agent Cb...l,. ;eeS one or a ~Lu~e of 15 more than one seq~leete~i~ agent which is effective for stabilising peroxide against iron, copper or mqng~qnese under alkaline cl~n~liti~ne but subet-qntiqlly ineffective in stabilising peroxide against deco~osition by cobalt.

The Group A seql-~oet~ agent is p,cf~ably sPlP~,lc~l from co~o~ds having ~ 06.
20 donors as ligands, such as tr~acycloa~ne eC.~ eeqre~q1ly l~4~7~ yGlnnnn-q-~es (TACN), or DPA, as well as some phosphonate cnn~ro~ln~ls wherein the mnle~fle has limited fl~ ~Il.;l;ly and ..~op,~e spacing of the ligands such as DACE DACH and/or DPA are p~ iul~ly pl~f~ .d. The group B seq~est~in~ agent is pl~f~.dbly a non-cyclic alkylene amino poly(methylene pho~l.h-~ ~iç acid) or other ~ n~ acid co~uund or salt 25 t_ereof, especially the following agents under the tradename Dequest: such as Dequest 2006 (aminotris(methylene ~hosrhoni~ acid)) sodm,m salt; ethylene diamine tetra (methylene pho~erhnnir acid) or the sodium or pot-q-c~lm salt (e.g. Dequest 2046 which is the sodmm salt) and diethylL ~ .ninepenta (methylene phoslrhnnir acid) (Dequest 2060) or l-hydroxyet~ne~ rh-~srhonir acid sold as Dequest 201û or qnq1o~es with higher CA 02252497 l998-l0-l6 alkylidene groups. D2060 and its sodium salt D2066 are particularly l)refelled. Other Group B useful sequestering agents are those sold under the trad~n~me Briquest from Albright and Wilson.

The composition is preferably ethanol-free, more preferably free of all volatile monohydric alcohols (i e. having flash point about the same as or lower than isoyr~yyl alcohol). The con~ntr~te composition is ~lk~line Preferably, the composition will have an i~ial pH of at least 9, preferably 9 to 11 and most prer~lably 9.5 to 10. The pH of the composition a~er 6 weeks storage at 37~C is plereldbly still greater than 9 and after 12 weeks storage it is still greater than 8.5.

The amount of the Group B sequçstern~ agent to be incorporated into the oxidising composition of the invention is at least 0.005% by weight, preferably at least 0.01% by weight. (~.r~lly, it will be no greater than 2% by weight, preferably no greater than 1%
by weight and most yrer~rably no greâter than 0.5% by weight ofthe total composition.

The amount of the Group A sequçstçrmg agent to be incûlyurated into the oxi~ g composition of the invention is at least 0.005% by weight, preferably at least 0.01% by weight, y~f~lably no greater than 2% by weight or no greater than 1% by weight or, more particularly from 0.02 to 0.6% by weight.

Further optional Se~luR~ e agents may also be incolyoi~led in the oxi~li~g composition.
Where present, such fu~ther optional seq..est~ agents are preferably added in amounts of at least 0.0005% by weight, pr~fer~bly no greater than 2% by weight, more particularly in the range of from 0.01% to 1.0%, most preferably in the range from 0.02 to 0.6%, by weight.

The invention will now be d~ ed with reference to the following non-lim~ng e~mrlec .

CA 022F,2497 1998- lo- 16 Ex~ les 1-2 ~n~l Co-~ative F,xamyle A

Test fo~ tinnc were pr~p~ed using 0.3% sodium percarbonate (Example 1) and 0.5%
sodium yc;llJol~te tetrahydrate (Example 2). They were co~ed against a control without 5 buffer and coll,y&l~live e ~ le A which contained 2% ses~luic~l,onate. Table 1 shows the results. Sodium ,I,c,~ ,nate does not give such effective peroxide l~t~ as the sodium perborate. Nevertheless the p~,rc~l,~ate buffering system could be used either aloneorin a 1...; ~.~ e withp~ olalefor~let~ swithshortshelf-lifele.~ e.~ s. Thesesquicarbonate gave good buffering but the peroxide loss is l~n~ccept~le. Further 10 ~ e showed that borax gave buffermg which was marginally worse than Exa,l.~lcs 1 and 2, but the peroxide loss was much worse.

Table 1 15 E~ample % Pero~de loss 37~C

Week Weeks Weeks Weeks Control 0 2.91 0.97 9.71 1.08 8.6 6.45 9.68 2 1.01 3.03 2.02 5.05 A 34.29 66.67 74.29 92.38 E~ample pH 37~C

Week Weeks Weeks Weeks Control 9.55 9.35 9.34 8.88 9.81 9.7 9.69 9.47 2 9.65 9.51 9.52 9.37 A 9.91 10.00 10.02 9.96 F~ 1CS3 ~nd 4 ~hlonn~is added to mains water for .1;~ .r~ So...~ ';...fs the level of chlorine is so high that it can lead to fabric dye damage when clothes are repeatedly washed in it. The use of 5 low levels of peroxide in a liquid deh.~ form~ t;rm should cause a reachon with the chlorine which will reduce chlonne ble2~hing Peroxide also provides enhanced ~l~~~hing in sohltion to give reduced damage from dye transfer during the wash. Such a "colour safe"
fo~ tinn ~ s the use of a buffer for pH stability on storage if it is to deliverc~iQf~r,tory removal of fatty soil in the wash.

Colour safe liquid cG.~ou~ions were pl~a~cd containing as sll~ct~nt a 10:2 ratio of a Primary alcohol (C13.15 ) ethoxylate, ethoxylated with 7 moles of ethylene oxide: linear alkyl (Cl~,3) b~n7~e sulphonic acid; giving a total of 12% actives. The composition also ;.~/h,~ 2%w/w sodium citrate as a builder, 0.02%w/w Acid Blue 80 dye as colorant and 15 0.20% Tinopal CBS-X a distyryl biphenyl derivative ex Ciba Geigy, as an optical brightening agent. All the chl.q.o- A ;~.lQ had a seqlles~nt system. Control 1 and Example 4 were sequestered with ~t 0.1% Dequest 2066 and Control 2, E~ les 3A and 3B were sequestered with 0.1% Dequest 2066 and 0.03% DPA. The initial pH of the liquids was a~lQted to 10 using 50%w/w sodium hydroxide (co..~ -g 0.5%w/w Dequest 2066).
r~oAide was added either as 60% wlw H2O2 sol ltinn alone (in the controls) or with 0.5%
wlw sodium perborate tetrahydrate as a buffer, to give 1% wlw total hydrogen peroxide equivalents in the cullhoL and the examples. The order of ad~ n of the cotnponPnts was perborate, then peroxide solution, then sodium hyd~o~,de. The composition of the le5 was as follows:
Control 1 - 1% H2O2 (no buf3~er) Control 2 - 1% H2O2 (no buffer) FY~mple 3A and 3B - 0.85% H2~2 + 0.5%w/w so~m p~.bûlale buf~er Example 4 - 0.85% H ~2+ 0.5%w/w sodnun pc~bolale buffier ... .. . . .

Ex~mples 3A and 3B were prepared as i~enti~ql ~ rli~tes to check the reproducl~ility of the l,u~ered syste~ Reproducible stability is a key re~luirc~n~ for a co~e~c;al system Many ofthe pnor art systems are capable of grving good stabil~ on a one offbasis but the e~ect is not reproducible.

The fonmll~ti-~n~ were stored at 25 and 37~C and the pH and available oxygen measured periodically. The results are given in Table 2.

Table 2 E~ample pH
l~tial pH 2 Week 4 Week 6 Week 37~C 37~C 25~C 37~C
Control 1 10.01 8.98 8.63 9.71 8.46 Control 2 10.01 8.65 8.04 8.86 7.71 3A 10.02 9.72 9.6 9.74 9.46 3B 10.01 9.81 9.61 9.78 9.48 4 10.01 9.69 9.53 9.78 9.31 E~ample % Pero~ide 1O9S
~al 2 Week 4 Week 6 Week % Pe~o,u~e 37~C 37~C 25~C 37~C
Added Control 1 1.05 2.86 5.71 0.00 5.71 Control 2 1.01 1.98 2.97 0.99 2.97 3A 0.99 5.05 5.05 1.01 6.06 3B 0.99 3.03 3.03 1.01 6.06 4 1.00 4.00 3.00 2.00 7.00 Rllff~ i~ifi~qntly improved in ~ pli~te~ s 3A and 3B CQ..t~ 0.5% w/w . .

sodium pt;ll,ol~e tetrahydrate in solution as a buffer. All e~-q-tnples show similar peroxide stability after 4 weeks storage at 37~C. It is known that peroxide is inherently more stable when the pH is lower. The stability of the two examples c~ ; g sodn~m perborate te~ahydrate is reproducible especially for longer test periods. The ben~fir~ql e fect of using 5 the soluble persalt as a buffier is obtained for both sequestr~q-nt systems.

The wide utility of the invention is further illllctrated by the following cornpos*ions w~ich may be fnrmnt~ell using the bllff~rine system which forrns the subject of the invention:

FYqm~le 5. K*~h~ Sl~r~y ClPqn~r %

D~ e~ Water To 100 IIy~ogen Peroxide (as 100%) 3.00 P13S4 O.S0 Dequest 2066 0.25 DPA 0.02 Sodium Hydroxide To pH 9.5 Synperonic A7 2.50 *Proglyde DMM 3.00 * Dipropylene glycol dimethyl ether . .

-1~

~xaTr~ple 6. Hard Surfa~P Cl~sner %

Deionised Water To 100 HydrogeD Peroxide(as 100%) 4.30 PBS4 1.00 S~ onic A7 3.00 DPA 0.03 Dequest 2066 0.25 SodiumHydroxide TopH9.5 FxaTr~ple 7 G~eral Purl~ose Cl~an~r %
Deionised Water To 100 Hydrogen Peroxide (as 100%) 3.70 C~ic Acid 3.00 PBS4 3.
Dequest 2066 0.25 DPA 0.02 Sodmm Hy~hu~dc To pH 9.50 Synperonic A7 7.00 W O 97/4SSl9 PCT/GB97/014S0 Fx~le 8 rh.~l Co~4~ t Fabric W~Chi~g Liquid . %

Deio-~ie.c,.l Water To 100 Secondary Alkane S~lrhl)n~te 8.00 S~l,ye~o~ic A7 2.00 Citric Acid 3.00 Dequest 2066 0.50 DPA 0.03 Silicone Oil 0.10 Hydrogen Peroxide (as 100%) 3.50 Sodium HyLu~dc To pH 9.50 PBS4 3.00 ,... ...

Claims (10)

1. Use of an alkali metal perborate or percarbonate salt as a buffering additive in the manufacture of an alkaline peroxide-containing liquid detergent composition, characterised in that the level of the persalt added, based on peroxide equivalent content, is less than 90%, preferably less than 75%, most preferably less than half of the total peroxide equivalent in the composition.

2. Use as claimed in claim 1 wherein the buffering additive is substantially fully dissolved in the liquid detergent composition.

3. Use as claimed in claim 1 wherein the buffering additive is a perborate salt.

4. Use as claimed in claim 3 wherein the buffering additive is sodium perborate tetrahydrate or monohydrate.

5. An alkaline peroxide liquid detergent composition comprising surfactant, a peroxygen bleach and a soluble buffer, characterised in that the peroxygen bleach is hydrogen peroxide and the buffer is an inorganic persalt selected from alkali salts of perborate and percarbonate, wherein the available oxygen from the hydrogen peroxide exceeds that from the persalt preferably by at least 2:1, most preferably by at least 3:1.

6. A composition according to claim 5 which further comprises a sequestrant system, preferably a combination of two sequestrants, one being a group A sequestrant and the other a group B sequestrant as defined herein.

7. A composition according to claim 5 or 6 in which the inorganic persalt in sodium perborate tetrahydrate or sodium perborate monohydrate.

8. An activated peroxygen bleaching system comprising a dispensing container with two compartments one of which contains a bleach activator and the other of whichcontains a composition as claimed in claims 1 to 7.

9. A method of cleaning laundry comprising the direct application to the laundry or a selected part of the laundry of a composition according to any one of claims 5 to 8, optionally followed by a rubbing action.

10. A method of cleaning laundry according to claim 9 in which the direct application is followed by washing the laundry in an automatic washing machine with the additional use of a conventional laundry detergent, optionally containing a bleach activator such as tetraacetyl ethylenediamine.