CA2010442C - Liquid detergent composition - Google Patents

Abstract

An aqueous structured liquid detergent composition comprising detergents active materials and a peroxygen bleach compound, said detergent composition showing less than 25%, preferably less than 10 %, more preferably less than 5 % volume increase while stored at a temperature between 20 and 37°C for three months after preparation.

Description

20 1 0442 C7151(R) LIQUrr~ DETEl~GEl~T COMPOSITION
The present invention relates to liquid detergent compositions which contain a pt lV;~yZ~ bleach compound.

It has been proposed in EP 293 040, published November 30,1988 and EP
294 904, published December 14,1988 to incorporate solid, water-soluble p~ Ay~ll bleach compounds m liquid detergent compositions. The compositions as disclosed in these patent application comprise substantial amounts of water miscible solvents for ensuring that the amount of available oxygen dissolved in the liquid phase is not greater than 0.5%.
These high amounts of solvents are however i~",~l;",~ disadvantageous in that they tend to decrease the solid-suspending properties of the detergent composition, because they are believed to prevent the internal structuring of the liquid detergent composition.
It has now surprisingly been found that stable aqueous liquid bleach ; l lg detergent compositions can be f~rm ~ t~fl, which are structured.
These ~ osili~ s do not need to contain high -structure destabilizing-amounts of solvents for bleach stabilisation. Lower amount of solvents are especially preferred, because it is believed that the absence of high levels of solvents renders it possible to make detergent-structured compositions having good solid-suspending properties.
A~uldil~,ly the present invention relates to an aqueous structured liquid detergent composition comprising one or more detergent active materials and a ~ y~ll bleach compound, said detergent composition having a pH above 6.5, being structural and showing less than 25% volume increase, preferably less than 10%, more preferred less than 5% while stored at a temperature of between 20 and 37C for three months after preparation.
Preferably the detergent composition comprises less than a *
structure destabilizing amount, more preferably less 20~ 0442 2 C 7151 (R) than 10% by weight Or a water m;cr~hlf- organic solvent.
The present invention is cnnl Prn~t with LLU~ LuLed liquid detergent compositions, such c~Lu- LULed liquids 5 can be "internally structured" whereby the ~LLu-;LuLe is formed by primary ingredients and/or they can be ~Luu~uL~d by seonftAry additives such as certain cros6-linked polyacrylates or clays, which can be added as "external c,LLuuLuL,~ s'' to compositions of the 10 invention.
Such structuring is very well known in the art and may be deliberatQly brought about to endow properties such as cu.,~ preferred flow properties and/or turbid 15 appearance. Many ~.LLuuLuL~d liquids are also capable of sllcp~-nrt~n~ particulate solids such as detergency builders and abrasive particles.
Some of the di~ferent kinds o~ active-structuring which 20 are possible are described in the reference ~.A. Barnes, "Detergents" , Ch. 2 . in R. Walters (Ed), " h~ LL~:
Industrial Applications", J. Wiley & Sons, Letchworth 1980. In general, the degree of ordering o~ such systems increases with increasing surfactant and/or electrolyte 25 u~ t ~.Lions. At very low c~,l.cel.LL~Itions, the surfactant can exist as a molecular solution, or as a solution of spherical micclles, both of these being isotropic. With the addition of further surfactant and/or electrolyte, ~LLuu~uLed (antisotropic) systems 30 can form. They are referred to respectively, by various terms such as rod-micelles, planar 1 ~ r D~LU~;~ULeS~
1 -llAr droplets and liquid crystalline phases. Often, different workers have used dlfferent t~rm1nnlogy to refer to the ~.LLuuLuLes which are really the same. For 5 instance, in European patent specil'tn?.tion EP-A-151 884, l Ar droplets are called "spherulites" . The presence and identity of a surfactant structuring system in a liquid may be det~-rmtn--cl by means known to those skilled in the art for example, optical techni~ues, various -` ~ Z0~10442 3 C 7151 tR) _~ ~tLlcal mea-,uL. ~, x-ray or neutron diffraction, and 8 ' ~ , electron mi~;Lusuu~y.
Electrolyte may be only dissolved in the aqueous 5 continuous phase or may also be present as g -~pPn~
solid particles. Particles of solid matQrials which are ~n~slllhle in the aqueous phase may be s~rPn~P~
alternatively or in addition to any solid electrolyte particles .
mree common product forms in this type are liquids for heavy duty fabrics washing and liquid abrasivQ and general purpose cleaners. In the first class, the ~ ~L~ P~l solid can comprise suspended solids which are 15 substAnt;Ally the same as the dissolved electrolyte, being an eYCeSs o~ same beyond the solubility limit.
miS solid is usually present as a ~ LU~I~Cy builder, i.~. to counteract the effects of calcium ion water hardness in the wash. In the second class, the sl~pc~n~Pd 20 solid usually comprises a particulate abrasive, insoluble in the system. In that case the electrolyte, present to contribute to the structuring o~ the active material in the dispersed phase, is generally dif~erent ~rom the abrasive ~ . In certain cases, the 25 abrasive can however comprise partially soluble salts which dissolve when the product is diluted. In the third class, the structure is usually used for ~hirkPn~n~ the product to give uu~ preferred flow properties, and sometimes to suspend pigment particles.
Compositions of the f irst kind are described in for example our patent specification EP-A-38,101 whilst _ le~ of those in the second u~.Le~uLy are described in our spPn~ cAtion EP-104,452. Those in the third 35 category are for example, described in lJS 4,244,840.
The dispersed :~Lu~;~uLlng phase in these liquids is generally believed to consist of an onion-like configuration comprising Cullc6ll~Lic bilayers of Z~)1044Z

4 C 7151 (R) detergent active molecules, between which i5 trapped water (aclueous phase) . ~hese conflguratio ls of active material are somQtimes referred to as 1; -11 ;'lr droplets.
It i8 believed that the close-packing of these droplets 5 enables the solid materials to be kept in suspension.
The 1 -llAr droplets are themselves a sub-set of 11 11 Ar ~sLLu-;LuLe_3 which are capable of being formed in detergent active/aqueous electrolyte systems. For the purpose of the present invention, detergent compositions 10 of the 1~ -11 Ar droplet type are preferred.
The ~eroxYqen bleach The compositions according to the present invention 15 comprise a peroxygen bleach. ~his bleach L may be present in the system in solubilized form, but also possible is that only part of the peroxygen bleach is 5~ h71770d, the L~ 7n;n~ part being present as solid p~u~y~el~ particles which are Sll~r~n~7Pd in the system.
Examples of suitable p~LU~y~7~ include l~y-lL~ peroxide, the pel. uL~tes, persulfates, peroxy disulfates, peLI~ho~,,hates and the crystalline pl:Lu,~ylLy-lL~-tes rormed by reacting hydLuc7dll peroxide with 25urea or alkali metal carbonate. Also ~nrArAI71 ;-ted 7,~1DArh~A may be u8ed. Preferred hlPArh~A are only partially soluble in the system such as for example diperoxy~ rAn~'~ oic acid (DPDA) or other peracid crystals and perboratetetrahydrate. The bleach . _ L
30 is preferably added in an amount CULL~ .ng to 0.1 to 15% by weight Or active oxygen, more prererred from o . 5 to 596 active oxygen, typically from 1. 0 to 3. 0 9~ active oxygen .
35 The bleach ingredients may for example be added to the composition as a dry particulate material or as a predispersion o~ ble~ch particles. Ir peLbuLe.te-tetrahydrate bleaches are used, a suitable - ~ial available bleach dispersion is Proxsol (ex ICI), -5 2 0 1 0 4 4 2 C 7151 (R) altQrnatlvely perborat~-tetrahydratu crystals may b~
~ormed in-sltu ~or example as d~nrihed ln EP 294 904.
Deteraent active r~aterials In the wldest deflnltlon the detergent actlve materlals in general, may comprlss one or more sur~actants, and may be selected from anlonic, catlonlc, nonlonic, zwitt~r10n~c and amphoteric species, and (provided 10 mutually compatible) mixtures thereo~. For example, they may be chosen from any o~ the classes, sub-clas3es and specif ic materials described in "Sur~ace Activ~ Agents"
Vol. ~, by Schwartz & Perry, Interscience 1949 and "Sur~ace Active Agents" Vol. II by Schwartz, Perry 15 Berch (Interscience 1958), in the current edition o~
"2IcC~ I,eol,'s Emulsi~lers & Detergents" pl~hl~h~-d by the McCutcheon division of MAm~f~ctllring Confectioners Company or in Tensid-~ hPnh~lrch", H. Stache, 2nd }5dn., Carl Hanser VerlAg, Munchen & Wien, 1981.
Suitable n~n~on~c surfactants include, in particular, the reaction pLvd~.~;L~ of ~ _ - having a l.~dLv~hobic group and a reactive 1~ydL~-.~ atom, ~or example aliphatic Al.~nhnl~, acids, amides or alkyl phenols with 25 alkylene oxides, e~peci~l ly ethylene oxide either alone or with propylene oxidQ. Spee~c nnn~nn1c detergent are alkyl (C6-Clg) primary or seCon~Ary linear or hrAn- h~-cl AlcnhnlF~ with ethylene oxide, and products made by ennAQn~ation o~ ethylene oxide with the reaction 30 products oi~ propylene oxide and ethyl~n~ m~ne. other so-called non~nn~n detergent ~ _ '~ include long chain tertiary amine oxides, long chain tertiary rhn8rh~n~ oxideg and dialkyl 8ll1rhnY1~
35 Also possible is the use of saltin~-out resistant active materials, such as for example described in EP
328 177, pllhl;~h,~-l August 16, 1989, especially the use o~ alkyl polyglycoside surfactants, such as for example disclosed in EP 70 074, published January 19, 1983 X

~ 20 1 0442 6 C 7151 (R) Preferably thQ levQl of nonionic surfactants is more than 1 % by weight of the composition, preferably from 2.0 to 20.0 %.
5 Suitable anionic surfactants are usually ~-ter-noluble alkali metal salts of organic sulphates and 5~lrhnn~tes having alkyl radicals containing ~rom about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples o~
10 suitable synthetic anionic detergent ~ .ds are sodium and potassium alkyl sulphates, ~cppc~l ly those obtained by sulphating higher (C8-cl8) Al cnhnl A
produced for example from tallow or coconut oil, sodium and pota6sium alkyl (Cg-C20) benzene sl~lrhnnAtes~
15 particularly sodium llnear sC~r~nAAry alkyl (C10-C15) benzene Slll rhn"Ates; sodium alkyl glyceryl ether sulphates, ~-cpe~;Ally those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium 20 coconut oil fatty monoglyceride sulphates and sulphonates; sodium and potassium salts of sulphuric acid esters of higher (C8-C18) ~atty alcohol-alkylene oxide, particularly ethylene oxide, reaction pL~ldU~;~S;
the reaction PL~I1U~ S of fatty acids such as coconut 25 fatty acids esteri~ied with ~ceth~onl~ acid and neut--Al ~ A with sodium hydroxlde; sodium and potassium salts of fatty acid amides of methyl taurine; alkane - 1 rhnnAtes such as those derived by reacting alpha-olefins (C8-C20) with sodium bisulphite and those 30 derived from reacting para~ins with S02 and C12 and then hydrolysing with a ba~e to produce a random sulponate; and ole~in slllrhnnAtes~ which term is used to describe the material made by reacting olefins, particularly C10-C20 alpha-olefins, with S03 and then 35 neutralising and hydrolysing the reaction product. The preferred anionic detergent, -c are sodium (cll-cl5) alkyl benzene sulphonates and sodium (C16-Clg) alkyl sulphates.

7 C 7151 (R) Generally the level of the above mentioned l~v.. 30ap anionic surractant meterials is rrom 1-40 % by weight of the composition.
5 Preferably the weight ratio Or synthetic anionic surfactants to nnn~nn1~ surractants is from 10: 1 to 1: 10.
It is also possible, and E t.~ preferred, to include 10 an alkali metal soap of a mono- or di-carboxylic acid, PCpQC~Al ly a soap of an acid having from 12 to 18 carbon atoms, for example oleic acid, ric~n~lP1~- acid, and fatty acids derived from castor oil, rapeseed oil, yLuu~ L oil, coconut oil, pAlmkP~nPl oil, alk(en)yl 15 s~rinAtec e.g. dodecyl succinates or mixtures thereof.
The sodium or potassium soaps of these acids can be used. Preferably the level of soap in compositions Or the invention is form 1 - 40 % by weight Or the composition, more ~LefelLed ~rom 5 - 25 %.
In many (but not all) cases, the total detergent active material may be present at from 2% to 60% by weight of the total composition, ror example from 5% to 40% and typically rrom 10% to 30% by weight. However, one 25 preferred class Or compositions comprises at least 20%, most prererably at least 25% and Pcpc~c~lly at least 30%
of detergent active material based on the weight of the total composition.
30 Compositions according to the invention are pre~erably physically stable in that they yield no more than 2% by volume phase separation when stored at 25-C for 21 days from the time of preparation. ~cppci~lly prererred are compositions which do not yield any phase separation 35 upon storage ror 21 days at 25 C.
Compositions according to the invention, preferably have solid-s~ rPn~ln~ properties in that they yield less th2n 5 % by volume of s~Ai- t after storage for 21 at 25-C, ~ 20'q 04a~2 8 C 7151 (R~
more preferably less than 2 % by volume se~ - L is formed, most preferably 6ub6tantially no visible seA~- ~ is formed.
5 Preferably composition6 according to the invention comprise less than a 6tructure de6tabilising amount o~
water m1~cihl~ solvent, preferably less than 10% by weight, for example less than 7.5%, more preferred less than 5%, P~p~clAlly preferred less than 2.0%, typically 10 less than 0 . 5% by weight of a water miscible solvent.
DPp~n~ln~J on the other ingredients of the composition, it is however sometimes possible to incvL~vLate low levels of water miscible solvents, say from 0.1 to 8 %
15 by weight, more pre~erred from 2 to 6 %, without the o. ~;uL~Ice of structure destabilisation. In particular it has been found that these low levels of water ml~c~hle solvent6 may adv~ vusly be u6ed in combination with relatively high levels of dissolved electrolyte, say 2 0 more than 2 2~ by weight, more pre eerred more than 5 % by weight, ~:pQr~i~l ly preferred between 10 and 50 % by wcight. Bleach containing compositlons comprlslng water m~:r~hle 60lventg at level6 whlch do not prevent the ~ormation of ~Lu~;~uLlng~ ln partlcular internal 25 structuring, are also embraced within the 6cope of the present invention.
Example6 of water-misclble solvents are lower allphatic monoalcohols, ethers of dlethylene glycol and lower 30 -- 1 lrhAtlc monoalcohols, and mixtures thereo~.
Vol - ,f :~hi 1 i tY
I lquid detergent composition6 according to the invention 35 are volume stable in that they show less than 25%
preferably less than 10%, more preferably less than 5%
volume increase during storage at a t~ CI~ULt between 20 and 37-C for a period of three months after preparation .

Z0~04~

9 C 7151 (R) Although the type Or container for storage is believed not to be critical, g~n~rAlly liquid detergent compositions according to the invention will be stored 5 in closed bottles, say of 1.5 litre, which optionally may include venting means, for rPl~ n~ generated oxygen.
When a solid pe~;~,..y~ bleach ~ _ L is present in an 10 aqueous system, generally part Or the bleach material will be solubilized in the form Or pQracid and/or ll~dL~ell peroxide in the aqueous phase. One of the problems o~ten obsel~,.d in such systems is the occurence Or oxygen evolution, due to the de ~nition Or this 15 peracid or llydLo5~ell peroxide into acid and/or water and oxygen. The oxygen bubbles rormed may either emerge rrom the liquid or be trapped in the liquid, thereby causing a volume increase. A similar oxygen evolution i8 obsorved when the bleach ~_ _ such as ror instance 20 llydLo~él~ peroxide i8 totally solubilized in the system.
The present invention provides liguid detergent compositions wherein the volume increase is kept at an acceptable level of less than 25%, pre~erably less than 25 10%, more ~L~areLLed less than 5 %. during storage Or the composition at a temperature between 20 and 37-C ror three months after preparation.
The par2meter3 to be varied in the composition to bring 30 about the desired volume stability efrect may for example be the pH, the physical state o~ the lln~i cc~lved bleach particles when present, the amount o~ dissolved bleach, the presence o~ stabilising agents, the amount of dissolved bleach activators, the viscosity Or the 35 product directly after preparation, the presence of viscosity reducing polymers, the presence of gas bubbles in the composition directly arter preparation and the presence of antiroam agents. The choice of an optimum value of these parameters is ~r~n~nt on the nature and 20:L0442 10 C 7151 (R~
the cholce of the actiVQ materials which are present in the composition.
The half life time of the solubilized peracid or 5 llydLU-J~ll peroxide should preferably be increased for increasing the volume stability of the composition. Not only the amount of oxygen formed per time unit is less by increasing the stability of the peracid or llydLO~el~
peroxide, also -and this has been found more important-10 an increase in the life time of these . - ,u~ c will ~llow the oxygen bubbles to be formed upon A~ ition of the peracid or l~ydLUlJ~n peroxide to grow in size. An increase in the size of the bubbles to be formed i5 c~n~iAPred advantageous in that these larger bubbles 15 have been found to be less prone to contribute to the volume increase of the liguid detergent composition, in other words they tend to escape from the liguid rather than being sl-cp ~nA~cl into the system.
20 Preferably the halr-life time of the lly~LU~n peroxide or peracid is be more than 3 weeks preferably more than 6 weeks at 37-C at the conditions in the detergent composition, pre~erably more than 8 weeks e~c~pec1:~l ly preferred more than 10 weeks. Most pL~ f~LL~ d between 10 25 and 20 weeks.
The stability of the peracid or llydLUl'J61~ peroxide may be increased in several ways such as for instance a decrease in pH of the composition. It has been found 30 that the volume stability of the liguid detergent composition increases by decreasing the pE~ of the composition. Therefore, for the purpose of formulation volume stable compositions it is preferred to avoid the use of excessive high pH values. Preferably the pH of 35 the detergent compositions is less than 12, more preferred less than 11.5, ecpe~lly preferred between between 6.5 and 11, typically from 7 to 10.
It has al60 been found that the volume stability of the 11 C 7151 (R) detQrgent compositions according to thQ present invention can be ~ :~v~d by using bleach particles which are Pn~ArslllAted. These Pn~Ar~ ated bleach particles constitute part or all Or thQ bl~ach present 5 in the composition, the particles are mainly present in the composition in undissolved rOrm.
The presencQ Or bleach particles in l~n~solved form is also prererred when the bleach particles arQ not 10 ~n-Arsl~lAted. HighQr levcls of llnA~nlved bleach ar~
prQferred, becausQ it is believed that bleach instability is mainly instability of dissolved bleach.
Prererably at least 10% by weight, more preferably at least 30%, ~rer~Ally prererred more than 50~, most 15 pre~erably more than 75 % or even more than 90 % by weight Or the bleach i8 present in l~nr~ olved I~orm. Ir pQrboratQ hl ~A~ hP~ are used it has been round that the amount Or dissolved bleach is reduced if the pH o~ the composition is relativ~ly high say from 7-11, more 20 prererably from 7 . 5 to 10.
Pre~erably the weight average 1 ~; t - t Or the lln~ olved bleach particles is rrom 0.5 to 100 mi~ tar~ n~pec~lly S to 60 micrometer. A method rOr 25 obtaining thQse small particles is described in EP 294 904.
One way Or ensuring that the bleach is present in lln~ 501ved rorm ig to increase the amount Or 30 electrolyte in the composition, therewith reducing the solubility Or the bleach ~ _ in the system.
Suitable electrolytes ror this purpose are ror $nstance thQ at least partially water soluble carbonate, sulphate and hAlogen~ salts and ~ horAte. othQr prererred 35 electro]vtes arQ salting out electrolytQs.
For the purposes of the present invention the expression salting out electrolyte has the same meaning as in EP 79 646, published May 25, 1983, namely those electrolytes which have a Iyotropic 12 C 7151 (R~
number of less than 9 . 5 .
Typical eYamples of salting out electrolytes are water-soluble builder salts, such as alkali metal ortho- and 5 y,L~,~o~yllates, the alkali metal tripolyphosphats~s, such as sodium tripolyposphate, the alkali metal silicates, -borates, -carbonates, -sulphates, alkal i metal citrates;
alkali metal salts of nitri 1 oncet~te; alkali metal salts of ca b~ ryy succinate. Instead of the alkali metal 10 salts the illm salts can be used. Particularly preferred is the use of sodium tripolyphosphate and or sodium (di) silicate as the salting out electrolyte.
For ensuring an adequate reduction in solubility o~ the 15 bleach ~ L~ the dissolved part Or the electrolyte constitutes preferably more than 2 % by weight o~ the composition, more preferred more than 5% by weight, D~pec~ y ~L~5~eLled between 10 and 50 9~ by weight.
20 For obtaining good volume stability, preferably the compositions according to the present invention also comprise a st~hil i ~in~ agent for the bleach ' _ -nt.
Suitable stAhil ~Dr8 are well-known in art and include EDTA, MA7nDsi~ silicates and rho~l h- ~tes such as ror 25 instance the Dequest range ex M- naAnto and Naphthol ex Merck. Preferably the amount of s~hi 1 i P~in~ agent is rrom 0. 05 to 5 % by weight o~ the composition, more preferred from 0 . 05 to 1~ o~ the composition.
30 Compositions of the present invention may comprise one or more bleach activator agents. These materials when ,_ ~ lnecl with a peroxy bleach in the wash, will activate ll~lL~,g~ll peroxide at a low t~ LULe: of from 15 to 55C therewith allowing the effective use of peroxide 35 hlD Irhe~ at low washing temperatures.
The bleach activators used in the present invention, often also referred to as peroxyacid bleach precursors are conventionally organic ~ ds having one or more 13 C 7151 (~) reactive acyl groups, whlch at rQlatively low tt, ~~ atu~Q react with hydrogenpQroxid~ causing thQ
formation Or organi¢ peroxyacids, the latter providing for a more errectiv~ bleaching action at lower 5 temperatures than l~.I-oy~l peroxlde itself.
The best known organic bleach activator Or practical importance is N,N,N,N'-tetraacyl ethylene diamlnQ, normally re~erred to as TAED. Another well-known bleach 10 activator is sodium-4-benzoyl oxybenzene 8l-l rh~n~te normally referred to as BOBS, as d~ osed in GB 863 988, published June 9,1960.
Examples of other organic bleach activators are other 15 n-acyl substituted amides, for example tetraacetyl methylene diamine; carboxylic acid anhydrides for example 8~ c~n~-~, benzoic and phthalic anhydridess carboxylic acid esters, for example sodium acetoxy benzene sulphonates acetates such as glycerol-2 0 triacetats, glucos~ pentaactetate and xylose-te~rn~cetate and acetyl salicylic acid.
Preferably TAED is used as the bleach activator. The p- -:r~L-~ level Or bleach activator in the liquid 25 ~etergent is from 0.1 to 10 % by weight ~L~feLably ~ro~
0.5 to 5 % by weight o~ the composition.
Pre~erably the bleach activator is present in the system in at least partly l-nd1~solved form. Pre~erably 30 at least 10% by weight, more preferably at least 30~, P~pe~iAlly preferred mor~ than 50% by weight o~ the activator is present in l~n~ olved form.
One way of ensuring that the activator is pre6ent in 35 llnd ~ olved rOrm is the use Or ~n~rs~ ted activator materials. Another method is to increasQ the amount of ~31ectrolytQ in the composition, therewith reducing the solubility of the activator in the system. Suitable electrolytes ror this purpose are ~or instance the at X

~, 201044~

14 C 7151 (R) least partially water solublc carbonate, sulphate and halogenide salts and metaborate. Other preferred electrolytes are salting out electrolytes as defined hereabove .

For ensuring an adequate reduction in solubility, the dissolved part of the electrolyte constitutes preferably more than 2 ~ by weight of the composition, more preferred more than 5% by weight, ~periAlly preferred 10 between 10 and 50 ~ by weight.
AB to the viscosity of the product directly a~ter preparation, it has been found that a lower value for the viscosity generally increases the volume stability 15 of the bleach cr~nt~;nin~ product. Also for lower viscosities are genrally preferred by the cu.._ - r .
EIowever, for providing solid-s~lcp~n~lin~ properties, low viscosities should pre~erably be avoided. "~ o~ in selecting the most a~L~""Llate viscosity of the 20 product, a balance should be sought between better stability and ~ - -acceptance at lower viscosities and increased solid sllcp~n~l; n~ properties at higher viscosities .
25 Generally it is preferred that for good volume stability and good ~ --acceptance, the viscosity is preferably less than 2,000 mPas at 21 5-1, more preferred less than 1,500, most preferred between 20 and 1,000, F~cpec;Ally preferred ~rom 30 to 500. For good 30 solid sl~cpF~n~;n~ properties, it is preferred that the viscosity is more than 1,000 mPas at 10-4 8-l, more preferred more than 10,000, r~Cp~clAlly pre~erred more than 100, 000.
35 The terhn~ eC for obtaining the initial viscosity as desired are well-known in the art, and include for example the ay~ late choice of active ingredients, the adaptation of the level of dissolved electrolyte and the inclusion o~ viscosity modifying agents. A pre~erred 15 C 7151 ~R) way for regul~tlng the viscosity o~ the product is th~
inclusion o~ polymers in th~ composition.
Viscosity and/or stability regulating polymers which are 5 preîerred for incorpora~ion in compositions according ~o t:he invention include def locculating polymers e . g those having a hydrophilic b~-kb--n~ and at least one hydro phobic side chain. Such polymers are described in our copending British patent appl ;m~t;~nR 8813978.7, published December 2 0 , 1 9 8 9 , ( corresponding to EP 3 4 6 9 9 5 ), 8924479.2, published May 16, 1991, 891478.4, published May 16, 1991, and 8924477.6, published Nay 15, 1991.
Othcr polymers which could advnntAgeo~l y b~ used for 15 viscosity regulation are described in EP 301,882 ~Unilever P~C) and EP 301,883 (Unilever PLC). Preferably thQ amount Or viscosity regulating polymer, especially dQ~locc~ A~ting polymers, is from 0.1 to 59~ by weight Or thQ total composition, more prererred rrom 0. 2 to 29~ .
As to the presencs of gas bubbles in the det-:~,J6,.~
composition according to the invention, it has been round that botb thn size and the level o~ gas bubbles are ~ ~"1 pA t.~rs for det~rm~n~n~ th~ volume 25 Btability o~ the compo8ition. ~;~n~rAlly gas bubbles in th~ rorm o~ air or oxygen bubbles are i---L~l~,c~d into lisluid detergent compositions during proces~in~ o~ the composit$on, which usually involves a mixing stage.
It has been ~ound that it is generally preferred to reduce the amount of gas which is prcsent in the composition ~ust aftQr preparation. Preferably tho volume fr~ction o~ gali bubbles ls less than 5.0t, pre~erably less than 3.5~, most y~erelLad less than 2.0%, ~p~ciAlly 1Q88 than 1 ~ or evcn less than 0.5 %.
It has also been found that when gas bubbles are present, the volume stability of the liquid detergent compositlon ir.~;, a8e8 when at cv.~ al~t ga~ content the 40 average tl~ '~r o~ the gas bubbles in inv,~

16 Z01044;~
Pref erably the average diameter o~ thQ gas bubbles i5 above 0 . 25 mm, more pre~erred above 0 . 4 mm, most preferred above 0 . 5 mm.
5 Several techniques can be used for reducing the amount of gas bubbles and for increasing the size of the gas bubbles .
For example the presence o~ an anti~oam agent both 10 reduces the volume fraction of gas bubbles and increases the size of the bubbles present. Preferably the anti~oam agents are added at a level above the level commonly used for ~oam reduction of detergent compositions.
Preferably the level of antifoam agent is more than 0 . 2%
15 o~ the detergent composition, more pre~erred more than 0.3i of the composition, ~cpeciAlly pre~erred ~rom 0.4 to 2 . 0% o~ the composition. Suitable anti~oam agents include cl 1 ~ con~ antifoam agents, such as dimethyl polysiloxanes and/or silica particles.
Furth~ e it has been ~ound that the use of lower shear-rates in the mixing of the detergent compositions of the invention, decreases the amount of gas bubblas in the composition. A similar decrease can be observed when 25 mixing the detergent composition under deaerated conditions, by centrifuging the detergent composition after mixing, by leading a stream of large gas bubbles through the composition during or a~ter mixing and by vacuum deaeration of the product a~ter mixing.
30 ~e:por-l Illy pre~erred for obtaining the desired result is the centrifuging of the composition in the absence of 8llcpc-n~ d 801id8 and/or the vacuum deaeration Or the composition .
35 It should be noted that the choice of the values of the optimum set of values o~ the above r- ' ~nn~d parameters should be detc~rmin~d for each detergent composition individually while using the above given g~ l 1 nec. For certain compositions it may not be n~cDss~ry to optimise zu~04a~2 17 C 7151 (R) all of the above given parameters. For instance for some detergent compositions it may appear that if the amount and size o~ the gas bubbles present in the composition is ade~uately controlled, then a greater flexibility in 5 ~-h^,^~8~n; the viscosity and or pH of the system may be obtained, while still resulting in compositions satisfying the re~uired stability re~uirement. It is however believed to be well within the ability of a skilled man on the basis of the above ~e~-h~ng to 10 determine for each detergent composition an acceptable set of values for the above-mentioned parameters.
OPti~^~nAl in~ redients 15 When the compositions are of 1A--11 Ar ~LLU~.;l UL~ then in many cases it is preferred for the a~ueous continuous phase to contain dissolved electrolyte. As used herein, the term electrolyte means any ionic water soluble material. However, in l; -11 Ar dispersions, not all the 20 electrolyte is n_ c~A- lly dissolved but may be ~ ^L~ APA~ as particles of solid because the total electrolyte ~ tion Or the li~uid i5 higher than the s^~l~lhil ~ty limit of the electrolyte. Mixtures of electrolytes also may be used, with one or more of the 25 electrolytes being in the dissolved a~ueous phase and one or more being substantially only in the sll-pDn~Pd solid phase. Two or more electrolytes may also be distributed approximately proportionally, between these two phases. In part, this may depend on processing, e.g.
30 the order of addition of ^nts. On the other hand, the term "salts" includes all organic and inorganic materials which may be included, other than surfactants and water, whether or not they are ionic, and this term Pnl _-~.~P.~ the sub-set of the electrolytes ~water 35 soluble materials).
The only restriction on the total amount of detergent active material and electrolyte ~if any) is that in the 1 A~-1 l Ar compositions embraced in the present invention, ZQ~0442 18 C 7151 (R) together they must rQsult in formation o~ an aqueous r di5per8ion. Thug, within the ambit of the present invention, a very wide variation in surractant types and levels iB possible. The selection of 5 surfactant types and their proportions, in order to obtain a physically stable liquid with the required structure will be fully within the capability of those skilled in the art. However, it can be mentioned that an JL L~lIL sub-class of useful compositions is those 10 where the detergent active material comprises blends of different surfactant types. Typical blends useful for fabric washing compositions include those where the primary surfactant(s) comprise n~ n1t-nle. and/or a non-alkoxylated anionic and/or an alkoxylated anionic 15 surfactant.
In the case of blends of surfaotants, the precise proportions of each ~ L which will result in such physical stability and viscosity will depend on the 20 type(s) and amount(s) of the eleotrolytes, as is the case with conventional structured liquids.
The compositions optionally also contain electrolyte in an amount sufficient to bring about ~LL~I~;LUr lng o~ the 25 detergent active material. Preferably though, the compositions contain ~rom 196 to 60~, Dl~pD~i~l ly from 10 to 45~6 of a salting-out electrolyte. Salting-out electrolyte has the meaning ascribed to in spDr-if~tion EP-A-79 646. Optionally, some salting-in electrolyte (as 30 defined in the latter spDcification) may also be included, provided it is of a kind and in an amount oompatible with the other, L~ and the composition is still in ac~.,Ld~ e with the definition of the invention claimed herein. Some or all of the electrolyte 35 (whether salting-in or salting-out), or any substantially water insoluble salt which may be present, may have detergency builder properties.
In any event, it is preferred that compositions ~ Z~ 0442 19 C 7151 (R) accordlng to thQ present invention include detergency bullder material, some or all Or which may be electrolyte. The builder material is any material capable Or reducing the level of rree calcium ions in 5 the wash liquor and will prererably provide the composltion with other benericial properties such as the generation o~ an Alk~l ~nP p~l, the 5~ pPn~inn of soil removed rrom the rabric.
10 Examples Or rhnsrhnrous-containing inorganic detergency builders, when present, include the water-soluble salts, P~pP~ lly alkali metal pyrorhnsrhAtes, orthopho6phates, polyphosphates and rhn~rh~nAte5. Speciric examples Or inorganic phosphate builders include sodium and 15 potassium tripolyphosphates, phosphates and h~ hogrhAte5. phnsphnnAte sequestrant builders may also be used. Sometimes, however, it is pre~erred to m~n~mice the amount of rhn5rhn,~,u~ Laining builders.

20 r _ 1P~3 of n~,.. rhn~,h--, us-~ ~,..Ldining inorganic detergency builders, when present, include water-soluble alkali metal carbonates, bi~ArhnnAtes~ silicatcs and crystalline and amorphous al~minnqil ~cates. Specific include sodium carbonate (with or without 25 calcite seeds), potassium carbonate, sodium and potassium hi~-ArhnnAtes~ silicates and zeolites.
Examples of organic detergency builders, when present, include the AlkAl ~nP metal, ammonium and substituted 30 : ~llm polyacetates, carboxylates, polycarboxylates, polyacetyl carboxylates and polyl.yd~ y~-ulphonates .
Speci~ic examples include sodium, potassium, lithium, i llm and substituted ~ llm salts Or ethylPnP~i l Am; nPtetraacetic acid, nitrilitriacetic acid, 35 oxyd~ cinic acid, melitic acid, benzene polycarboxylic acids, CMOS, tartrate mono succinate, tartrate di succinate and citric acid.
In the context of organic builders, it is also desirable ~ 20~0442 20 C 7151 (R) to incc,L~,Lc~te polymers which are only p2rtly dissolved, in the aqueous continuous phase as described in EP 301.882. q~his allows a viscosity reduction (due to the polymer which is dissolved) whilst i~ L~n~Lclting a 5 sufriciently high amount to achieve a s~con~l~ry benefit, espc-a~Ally building, because the part which is not dissolved does not bring about the instability that would occur if substantially all were dissolved.
10 It is further possible to include in the compositions of the present invention, alternatively, or in addition to the partly dissolved polymer, yet another polymer which is substantially totally soluble in the aqueous phase and has an electrolyte resistance of more than 5 grams 15 sodium nitrilotriacetate in lOOml o~ a 5~ by weight aqueous solution of the polymer, said second polymer also having a vapour ~L~UL~ in 20% aqueous solution, equal to or less than the vapour pressure of a reference 2% by weight or greater aqueous solution Or polyethylene 20 glycol having an average r~lem~ r weight of 6000; said second polymer having a molecular weight of at least 1000. Use of such polymers is generally described in our EP 301, 883 .
25 Preferably the level Or n~"~ noap builder material is rrom 5-50 ~ by weight of the composition, more ~Lb reLLed from 5 to 35 9~.
Although it is possible to ina-.~oLe.~e minor amounts, of 30 l~ydL~LLu~es other than water-miscible solvents, we pre~er that the compositions o~ the present invention contain low levels or are substantially free from llydL~LL~,~es. By lly.lL~,LL~"e is meant any water soluble agent which tends to enhance the solubility of 35 surfactants in aqueous solution.
Apart from the ingredients already mentioned, a number of optional ingredients may also be present, for example lather boosters such as alkanolamides, particularly the 2~)~0442 21 C 7151 ~R) nnl~711~7~7.~ derived from palm kernel ~atty acids and coconut ~atty acids, ~abric Sor~ e~. such as clays, amines and amine oxides, lather d~z~L~>a~lts~ inorganic salts such as sodium sulphate, and, usually present in 5 very minor amounts, fluuLesc~l.L agents, per~umes, enzymes such as proteases, amylases and lipases ~including r~7roJ;l~e (Trade Mark~ ex Novo), gp7~7i~j~PG
and colourants.
10 Compositions of the invention may be prepared by any conventional method for the preparation o~ liquid detergent compositions. A pret'erred method involves the dispersing of the electrolyte (non-builder) -if any-together with the minor ingredients except for the 15 temperature sensitive ingredients -i~ any- in water of elevated t~ GtULe:~ followed by the addition o~ the builder material -i~ any-, the detergent active materials (optionally as a pre-mix) under stirring and thereafter cooling the mixture and adding any 20 t~ LG-UL~ sensitivc minor ingredients such as enzymes or peLrl -- and the bleach. The r7P7~l~ o~77l~ting polymer -i~ any- may for example be added a~ter the elctrolyte ingredient or as the f inal ingredient .
25 When peLbuLGte ~~dLc.te is used ag the hLr lch~n~
agent, it may be preferred to cool the i~inal product to a t~LGLuL~ just above the freezing point, in order to accelerate the recrystallisation of the perborate in tetrahydrate form.
In use the liquid detergent compositions of the invention will generally be diluted with wash water to form a wash liquor, which may be used ~or detergency ~uLyoses, for example for the washing prûcess in a 35 washing machine. The cu,.c~ LGtion o~ liquid detergent composition in the wash liquor is preferably from 0.1 to lo % by weight, more pre~erred from 0.1 to 3 %.
The invention will now be illustrated by way o~ the 40 following Examples. In all Examples, unless stated to ~ Z0~0442 22 C 7151 (R) the contrary, all percentages are by weight.
/

23 C 7151 (R) R~ mnle 1 A baE~ic liquid detergent composition of the following 5 composition was prepared by addition under stirring of the _-- ' - in the order listed. Na-Dobs was formed in-situ by combining NaOH and Dobs-acid! Some of the proQP~in~ water was left behind because the I~YdLUg peroxide solution used was 27 weight % active.
_ ~ABLE 1 96 by weight Water balance Na-Dob6 13 . 8 Synperonic 7 4 . 0 Dec,uest 2 0 6 0 0 .1 X-Naphtol 0 . 2 STP ~h~ NW 8. 6 ~22 (10096) 5 . o pHl ) 7 . 9--8 . 1 25 TABLl~ 2a. Raw material E~pecification Csm~oncnt Su~lier Dobs-acid (98%), Marlon AS-3 EIUl~
Synperonic 7 I . C. I .
De~uc~t 2 0 6 0 Mr-n ~qA n1- o X-Naphtol, (p. a . ) Merck STP, ~hP _`-,,~ NW Hoech~t H22, 27% Brocacee 1) pH ad~u~ted with NaOH if ~cPs~:~ry.

20~0a~4:2 24 C 7151 (R) mnle 2 By varrying the Na-Dobs/Synperonic weight ratio and 5 keeping the total amount of actives ~ ;,L~..L, the basic detergent composition according to example 1 was p. :pa~c d in several versions of different viscosity direct after pr~ ation.
10 Composition A has a ratio Nâ-Dobs to Sy-l~eLOI~iC of 0.74:0.26 and a viscosity of 170 mPas at 21 s~l~
composition B had a ratio Na-Dobs to Synperonic Or 0.75:0.25 and a viscosity of 390 mPas and composition C
had a ratio Na-Dobs to Synperonic o~ 0.78:0.22 and a 15 viscosity of 1000 mPas. The compositions were stored at 37 'C.
Composition A showed in the ~irst two days of storage a slight volume increase of about 2% by volume, after 2 20 two days the volume in decreased to a volume which was about 1% less than the volume of the composition directly after pL~ tion.
Composition B showed a sharp volume increase of about 25 50% by volume in the first three days of storage, rollowed by a reduction o~ the volume until at the 5th day the composition had approximately its original volume .
30 Composition C showed during the first 7 days a sharp volume increase o~ more than 125~6 by volume (~velr a reduction of volume to the original volume of the composition was observed after 15 days.
35 This example illustra~es that by lowering the viscosity of the composition, the volume stability of detergent compositions containing solubilized hydrogen peroxide can be increased.

2~0442 25 C 7151 (R) Exam~le 3 The composition of example 1 was prepared by the method 5 as indicated in eYample 1, with some small modifications .

Compo6ition D was ~re~aled according to example 1, the ratio Na-Dobs to Synperonic was 0.77:0.23. Composition E
10 was pLe~c..ed as composition D, but 0.1% Or ~il ;c~n~
antifoam was added (COLL.~ d;n~ to 0.33 % DB31 ex Dow Corning) before mixing thQ ingredients. Composition F
was pL.~JaLed as composition D, but the composition was deaerated by centrifuging for 5 min at 4000 G.
15 Composition G was prepared as composition D, but 0 . 33%
o~ DB31 was added and the composition was de-aerated by centrifuging for 5 min at 4000 G. The viscosity of compositions D-G was 860 mPas after p~ tion. The compositions were stored at room t~ _ e.ur e and the 20 volume increase and the bubble size were monitored.
Composition D showed a linear increase in volume up to a maximum of about 75~ volume increase after 30 days of storage. The d~ r of the gas bubbles present during 25 this period showed a similar increase from very small (about o.l mm) to about 1.5 mm after 30 days. After 30 days the volume o~ the compositions decreased gradually until the composition was back at its original volume after 60 days. The bubble diameter stayed constant at a 30 value of 1.5 mm during this period.
Composition E showed a linear increase in volume up to a maximum value of about 55~ volume increase after 30 days of storage. The diameter o~ the gas bubbles present 35 during this period showed a similar increase from very small (around 0 . 25 mm) to 2bout 1. 8 mm after 30 days.
After 3 0 days the volume oi~ the composition decreased gradually until the composition was back at its original volume aîter about 60 days.

20:iL0442 26 C 7151 (R) Composition F showed an increase in volume during the ~irst 7 days to a maximum value of about 1096 by volume.
After 7 days the volume increase decreased to a value Or about 096 ana remained constant during 60 days of 5 storage. The diameter of the gas bubbles present during this period L. ~nc~d substantially ~unr~L~l-L at about 1.5 mm .
Composition G did not show a substantial increase in 10 volume during storage ~or 60 days. The diameter of the gas bubbles present during this period showed an increase from 1 mm to 1. 8 mm in the rirst 10 days Or storage, and then ~;. ln~-~ constant during the ro---~nl o~ the period.
This example illustrates that both the presence Or an antifoam agent and/or the de-aeration Or the ~ f,i~lon contribute positively to the stability of the liquid detergent composition.

203L04~2 27 C 7151 (R) Exam~le 4 Compositions were prepared according to example 1, with 5 some small modifications. Composition H was Or the composition o~ example 1, and had a viscosity of between 400 and 600 mPas, Composition I contained in addition to the _ 1~, of composition H 0. 596 by weight of nc~ a~,LL~-y~ ding to 1.5 ~by weight or DB 31 which 10 was added at the beginning o~ the mixing process. For both compositions the amount and the size of the gas bubbles in the liquid detergent just after pL~aL-t.ion was measured.
15 Composition H cnnl-~n~-d 5.2% by volume of gas bubbles, the size of the bubbles was between 0 .1 and 0 . 2 mm.
Composition I contained 1.996 by volume of gas bubbles, the size of the bubbles was between 0 . 25 and 0 . 5 mm.
This examples shows that the amount and size of gas bubbles in the detergent composition can positively be influenced by in~.c,L~oLc-tion of an antifoam agent during proc~,:Si n~.

28 C 7151 ~R) Exa~les 5-8 2 0 1 C 4 4 2 The ~ollowing compositions were prepared by addlng thQ
electrolyte to~e~hPr with the mlnor ingredients except 5 for the perfume and the enzymes to water of elevated tti ~ al_uL~, followed by the addltion of the detergent actlve material as a premix under stirring and thereafter cool$ng the mixture and adding the enzymes, p~L r, - - and the bleach .
T ~ WT ) 5 6 7 8 Na-Dobs 21 21 23.3 21 Synperonic 7 9 9 10 9 Glycerol 3 5 ~~ 3 9 15Metaborate 2 . 6 2 . 6 2 . 9 2 . 6 Nacitrate/ Citric acidl) 9 . 8 9 . 8 11.1 9 . 8 Deq tiest 2060S tas loO~) 0.4 0.4 0.4 0.4 Na-perborate tetrahydrate3) 20 20 __ 20 Na peLLvl~e - -~y.lL~te -- -- 7 . 2 --20Enzyme, ~ A1~ e 0.8 0.8 0.8 0.8 caC12 . 2H2 o . 2 o . 2 o . 2 0 .1 F1UVLeSCer, Tinopal C8SX 0.1 0. 1 0. 1 0.1 Silicon, Dow Corning DBloO 0 . 3 0 . 3 0. 3 0 . 3 Perfume 0.3 0.3 0.3 0-3 25~P~occ~ ting polymer4) 1 1 1.1 ethanol -- -- -- 2 . 5 water -----balanc~
pH 9 9 9 9 30 1) ~rhis mixtur~ i~; used to adjust the final pH
2~ E.~y.essed as a of analysed enzyme level in the frsh sample 3) as 100 ~ perborate, added as a dispersion (Proxsol ex ICI, approximate 65~ perborate dispersion in water with 35 an average perborate particle size of 40 mi~ Pr.
4) dPflocc~lating polymer o~ ~ormula I o~ EP 346 995, wherein x~50, y-0, R5~H, R6-CH3, Rl- -C0-0, R2 and R3 are absent, R4~ -C12H25, mW~ 7,500.

29 C 7151 (R) 5) wt% -approximate- of total pelLoL lte, obt~Lned by remov~l o~ the undissolved bleach particles by mild centri f ugation .
6 ) not -~ 3~ d 5 The obtained products had the followlng rhAri~o~eristics:

Volume stability (% volume 4 3 0 n.m6) increase, 3 months 25 C) clear layer separ~tion no no no no 10(3 weeks 37 C) solid 8~ Ation no no no no (3 weeks 37 C) Vlscosity 21 s~l 1, 350 710 800 n.m Viscosity 10-4 s~l 5P200,000 n.m n.m n.m 15dissolved perborates5) 3 1.5 8 n.m bleach activity % 99 99 96 n.
(2 months ambient T) enzyme activity % 65 62 76 n.m (2 ~nonths ambient T) 2) X

Claims (14)

1. An aqueous liquid detergent composition comprising detergent active materials and a peroxygen bleach compound in an amount corresponding to 0.1 to 15% by weight of active oxygen, selected from hydrogen peroxide, perborates, persulfates, peroxy disulfates, perphosphates, peracids and the crystalline peroxyhydrates formed by reacting hydrogen peroxide with urea or with alkali metal carbonate, wherein the detergent composition has a pH
above 6.5, said detergent composition being structured and showing less than 25% volume increase while being stored at a temperature between 20 and 37°C for three months after preparation.

2. An aqueous detergent composition according to claim 1, wherein the structure is formed by the detergent active materials.

3. An aqueous detergent composition according to claim 1, wherein the structure is formed by external structurants.

4. An aqueous detergent composition according to claim 1 having solid suspending properties.

5. An aqueous detergent composition according to claim 1, comprising less than a structure destabilizing amount of a water miscible solvent.

6. An aqueous detergent composition according to claim 1, having a pH
between 6.5 and 11.

7. An aqueous detergent composition according to claim 1, wherein the composition further comprises an amount of electrolyte which is sufficiently high to effect that at least 30% by weight of the bleach is present in undissolved form.

8. An aqueous detergent composition according to claim 1, comprising one or more stabilising agents for the bleach compound.

9. An aqueous detergent composition according any one of claims 1 to 8, comprising a bleach activator.

10. An aqueous detergent composition according to claim 1 having a viscosity at 21 s-1 of between 20 and 1,000 mPas, and a viscosity at 10-4 s-1 of more than 10,000 mPas.

11. An aqueous detergent composition according to claim 1 comprising 0.1 to 5.0% of a deflocculating polymer.

12. An aqueous detergent composition according to claim 1 comprising just after preparation less than 5.0% by volume of gas bubbles, said gas bubbles having an average diameter of more than 0.25 mm.

13. An aqueous detergent composition according to claim 1 comprising more than 0.2% by weight of an antifoam agent.

14. Method for the washing of fabrics, comprising the contact of the fabrics with a wash liquor comprising from 0.1 to 10 % of a detergent composition according to claim 1.