CA2078157A1 - Aqueous liquid cleaning compositions - Google Patents

Abstract

ABSTRACT

A preferably mildly alkaline aqueous liquid cleaning composition, especially but not exclusively adapted for use in automatic dishwashing machines comprising an enzyme, encapsulated bleach particles, a reducing agent in an amount of from 0.01 to 0.5% by weight and water in an amount of not more than 55% by weight is disclosed. The compositions show excellent enzyme stability.

Description

2 ~ 7 ~ 4 ~ k ) A~UI;~U:; LlQUlL~ ~L~:ANl~IG CC~M~C~SITIONS
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TECHNI C~L ~ ~LD
This inven~ion ~elates to a~ueou~ uld cleaning c:ompositions comprising an enzyme an~ encap~;ul~ed ~}each par~-icles. ~n ~t~rt.;~:nl~r, i~ r~lat~s to enzymatlc aquec~u~
li~ le~ning c~mpo~itions, e5pççlally bu~ n~
exc~ ely adap~ed fo~ use in au~oma~c dishwashin~
machine6, co~nprising an enzyme, encapsula'ced blea~
partioles and a reducing a~ent~
~..1 10 ~BÇ ~ ROUN,D ~ ~;.INVENTION
Cleanin~ C~mposition~ havln~ a combination o~ bl~ac~ing actio~ ~n~ ~.n~ym~.i c ~r~ati~n ~f blochemic~l ~oils, which co~pri~e a slow re~easo ~xidan~ bleach c~mposition in the ~orm of encapsulated bleach pa~ticle~ which d~lay the lS appearance of the ~u~l con~entration o~ the oxidant bleaoh but havi~g the tendency to rele~se a ~mall de~ctiv~tin~
a~oUnt o~ the oxidant, prior to the full ooncentration o~
the bleach being released, a biological soil-~egradin~
enzyme and an amoun~ of a che.mical reducing a~ent effective ao to dalay ~he appea~anCe of an enzym~-deac~ivating con~entra~ion of oxidan~ bleach compositlon until the ~ull oncentra~ion of the oxidant bleach composi~ion is released, are kn~wn ~nd described in llS P~ent Specif~cation 4,421,~;64. Tl~e ~ormulation o~ such detergen~
25 compositions in the ~orm o~ a dry sQli~ ~3c)wd~red ~r ~ranula~ s~a~e present~ nc~ problem and create~
subs'cantially no di~ ult:i~s with respect to enzyme stabil~ty clurin~ s~o~age. Howeve~ uch composi~ions ar~
~ormulated as an aqueous~ liguid, er;zyme ~3~orag~ stabillty 30 becom~s a problem, ev~n at mi~der alk~line pH vallle~
wher~ln en2ymef:~ are normally easier to stabilize.

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C 7284 (R) 2 2~7~1 ~7 In the area ~ "sa~e", i.e. mild maehine dishwashing liquids, the eviden ::e to date sugge~ts that the incor~ora~ion of enzymes into aqueous liquids~ containlng oxidant bleach encapsula~es ~either chlorine or oxygen~
ylelding oxidizing bleaches) may not he viable because o~
poor en~yme stability, cau~ed by even a v~ry slight leak~ge ~rom the bleach encapsulates into the bulk liquid. ~t has been found that only 4 ppm. available ~hlorine is enough to quickly destroy all th& amylase ~an amylolytic enzym~) and about l~o ppm. available ~hlorine will destroy all Savin~se~ (a pro~eolytic enzyme), incorporA~d in~o a m~del aqueous non-ph~sphat~ machine dishwashin~ liquid produ~t formu~ation.

Addi~ion of a reducing ag~nt, such as ~iodilam ~;ulphite, as sc~venger Por the oxid~nt as p~oposed in U~ Paten~
4,421,664 doe~ not improve the enzyme stability su~iciently enough ~o arriv~ at a oommercially vi~ble product with adequat~ and consi~tent p~rformance of both the enzyme and the bleach. Apparen~ly, in a~ueous liquid compositions, the reducing agent is no~ su~icient~y e~ective to scaven~e ~ xidant for a sufficient amount of time.

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It is -there~ore an obj~ct of the present inv~n~ion to improve the stability o~ ~gueous liquid cleaning ~o~positions comprising an en~y~e and a~ oxidant bleach in th~ f orm Of encapsulatec~ ch pa~ticles .

It ha~ now surprisin~ly been round that th~ enz~me ~t~bility in such ~ueous liquid cleaning ~omp~ltion~ can b~ ~u~stan~ially improved if the ~omposi~ion ~ul~ile the ~ollowing two oon~litions, i.e. a wate~ content o~ no~ more t~an 55~ by weight and containing 2~ reduoing agerl'C in an 35 amount of~ ~rom O . ol tc~ O . 5% by weight.

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C 72~4 (R) ~7~
DE$CRIP~ION O~ THE INVF,N~ION

Accor*inqly, ~he inven~ion provide~ ~n impro~ed aqueou~
liquid cleaning ~mp~sition ~omprising a deterg~n~y builder, an enzyme, encapsula~ed bl~ach particles and a reducing agent, characte~ized in that the compo~ition ha~ a water conten~ oP not more than 55~ by weight, pre~erably no~ more than 50% by welgh~, and the reducing agent is present in an amount of fro~ o.ol to 0. 5~ by ~eight.
1~
Tlle term "aqueoUs liquid" used herein encompasses low-viscosity li~uids to the Inore highly visaous liquids a~
well ~ gels and pastes, having wa~er content~ of ~rom about 10-55~ by wei~ , pre~exably from 25-55~ by welght, and moræ preferably from 35-5~% by weight. Preferably, the compos~tion of the invention is ~ mildly alkaline ~ueous li~uid .

By ~mild" is ~eant here ~ha~ ~he neat compo~ition wlll hav~
a p~ of fr~m about ~.0 ~o a~ou~ 10.5, pr~ferably fr~m abou~
6.5 to 10. 5, more ~re~erably from about 8 to 9.5.

The Deterq~nCy ~uil~er Soluble de~erqency ~uilder sal~s usef~l herein Gan be of ~5 ~le p~ly-valent il~org~nic and poly-val~nt organic types~ or mixtures ~hereof. Non-limiting examples o~ sui~ble w~Ar-soluble, inor~anic alkaline det~rg~ncy builder salt~
include the alkali metal carbonate~, borates, pho~pha~es, polyphosphates, tripolyphosphate~, ~icarbonate~ and s~ ates. Specifi~ ~xa~pl~s o~ such salts include ~he sodium an~ po~assium tetraborates, bicarbonates, ~arb~n~tes, tripol~phosph~s, or~hophosphates an~
hexaJno~aphosphatesg 3~ Examplee of sui~abl~ o~gan~ al~alin~ de~rge~cy bullder salts ar~ water-soluble ~mino p~lya~etates, e.g. sodlum .

c 7~4 (R) :~7~3 ~
and potassium ethylene~iami~e tetra~ce~ates, iao~ at~ (2-l~y-J~ y~t.hyl)nit.l i~.~di~cet~tes;
(2) wa~er-soluble s~ts of phytic ~cid, e.g. sodium and potassium phy~ates; (3) water-soluble polyphosphon~ate~, including sodium, potassium and li~hium salts Or etnane hydroxy-l,l-dipho~phonic acid; sodium, potassium and lit~ium salts o~ methylenediphosph~nic A~i~ an~ t.he 1 ike.

Additlonal or~ani~ huil~er sfllt~ eilll her~;n in~ AP. t.h~
poly~arboxylate ma~erials describ~d in us Patent Specification N 2,264,103, includin~ the water soluble l alkalr me~al ~alts o~ melli~ic acid and citria ac~d, dlpico~inic acid, oxydis~cinic acid and alkenyl succinates. The water-soluble salts of polycarbox~l~te polymers and copolymers, such as are described in US Patent Speci~ic~tlon N 3,308,0G7, are also ~ultabl~ her~in.

It is to be und~rstood th~t, while ~he alkali metal salts o~ th~ foregoin~ inorgani~ ~nd organic poly-valent ani~nic bullder salts are preferred for use h~rein ~rom an economic standpoint, the ammonium, ~lkanolammonium, e.g.
triethanolammonium, die~hanolammoniu~, and the lik~, wa~r-soluble salts of any of the foregoin~ build~r anions are u~eful ~rein.
Ano~her class of ~ui~able builders i~ ~hat o~ the so-called water~in~oluble ~alcium ion-ex~lange builder ma~erials.
Examples ~hereo~ includ~ t~le variou~ ~ypes o~ water-insoluble crystalline or amorph~us alumino silicates, o~
which zeolites ~re the best-known representatives. Other use~ul materials are, for example, the lay~red s~licates, such a~ a product sol~ by Hoechst under ~n~ trad~ nam~
SXS-6.

M~xture6 of organi~ and/~r inorg~nia b~ilder s~lt~ can he u~ed h~r~in.

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Wh-le any o~ ~he pol~-v~lent builder materials are usef~l herein, the compositions of the inve~tion are preferably free ~f phosphate ~uilders ~or environ~ental and e~olo~ical ~easons.

Pr~f~rrP~ hn~l~Pr,~ fnr ll.SP in ~h~ tnv~n~ n ~r~ ~n~illm citrate ~ sodium carbollate~ and sodium bi~arbonate and ~ L~ L}l~r~ur, ~ d~ lt~ tl~ P. Tl~e potassium salte may be pr~ferred for solubility re~sons.
Preferably, ~he amount o~ huilders in the c:ompo~itic~n i~
from a~ou~ 5 ~o 609~ by weight, more pr~Serably from 25 to àbout''4 0% by we slht .

15 ~lla En~me~
Enzymes a~e used for many purpose~3 in vari~u6 fields wh~r~
biochemical reactions occur. In general, an en~yme can be described as a catalyst ~apable of permitting ~ b~ochemical reaction to quickly occur and can be classl~i~d a~cordihg to the ~ype o~ re~ction they ca~alyze. Enzyme~ are characte~ized by a high ~p~irici~y~ ~ha~ i5 to ~ay, each ~nzyme c~n catalyze a single reaction o~ one substanca or A
very small number of closely related substances.

25 Examp~e~ of en~ymes suitable for use in ~he cleanlng ~ompositions o~ this inventîon in~;lud~ lipases, pep~idase~, amylases (amylolytic en~ym~s~ ~nd others which degrade, alte~ or facili~a~e t~ egra~a~i~n ~r al~era~ion o~
biochemical soils an~ ains e~noount:~red in cleansing sit~a~lons ~ as to r~m~ve m~re easily the ~oil or ~taln from ~he ob~jeGt being washed to make the soil ~r sta~n more removable in a subsequent cleansing step. Both de~radati~n and alter~tion`-can improve soil rem~vability~ Well known and pre~err~d examplcs ~ th~s~ ~nzymes ar~ prot~es, lipases and amyla~. Lipase6 a~e clas~ e~ a~ EC sla~ 3, hyd~ola:3es, subs~lass EC 3.1, pre~r~b3,y ca~boxylic esl:er .
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hydrolases ~C~ 3~1.1. An example thereo~ are lipases EC
3.1.1;3 with the systemati~ nam~ glycerol es~er hydrola6e~.
Amyla5es belong to the ~ame g~neral class as lipa~s, subclass ~ 3.2, especially EC 3.2.1 gly~ose hydrolase~
such a~ 3.2.1.1. alpha-amyla~e with the sy~tematic name alpha-1,4-glucan-4-glucanohydrolas~; and alBo ~ . 2.1.2, beta-amylase with the systematic name alpha-~,4-gluc~n mal~ohydrolase. Pr~eases belong to ~he s~me c~a~ a~
lipases and amylases, subclass EC 3.4, particularly E~
3.4.4 peptide pepti~o-hydrolases su~h as E~ 3.4.4.1~ with the syst~matic nam~ sub~ilopeptidase A.

Obviously, the foregoing c~a~es should no~ be uGod to limit ~h~ scope of ~he invention. Enz~m~s ~e~ving diPferent functions can also he used in the prac~ice o~ thi~
invention, the sele~tion ~epending upon the composition o~
biochemical soil, in~en~ed purpoSe of a par~$cular composi~ion, and ~2~e availabili~y of ~n enzyme to degr~de ~r altex the soil.
Lipases, someti~es called esterases, hydroly~e fatty ~oil5.
~ipases suitable for us~ herein include those of animal, plant and mic~obiolGgical origin. Suita~le lipas~ are al~o found }n many strain of bacteria and fungi. For example, lipase~ suitable for use herein can be dcrived from ~eu~omonas, ~pergillus, P~umoeo~cu~, ~tsphyl~aoc~u~, Toxins, ~y~oba~texium ~ub~rculo~is, ~ycotorul~ Lipoly~
and Sclerotinia miaroorganisms, and can be m~de using re~ombinan~ DNA manufa~turing technlques.

~ui~able animal lipases; are found in tlle boày fluids ~nd organs o~ many species. A pr~çrred cl~s of animal lip~e herein is the-p~ncreatic lipase.

Lipa~ can be employed in the p~e~t cleAning compo~itiwn~
in an ar,ount ~ro= about 0.0~5~ to ~bout 10~, pre~r~bly ' `: ' '` ` ` ' ` ~ ' ~
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from 0.01 to 5% of the cleaning composi~ion, cn a pure enzyme ba~is.
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~ lle en~ymes most commonly used in machine dishwashing compositions are amylolytio enZymes.

The amylolytic enzym~ ~or us~ in the pr~cnt inventi4n can be those d~rived from bacteriA or ~ungi. Pre~'exred amylolytic ~nzymes a~e those prepared and de~cribed in l~ sritish Patent Specifi~tlon N l,2s~,839, cultivat~d ~rom the strains of sacillu~ licheniformi3 NCI~ 8061, NCIB 8059, ATCC 6334, ATCC ~5~8, A~CC 11 945, ATCC 8480 and ~TCC 9945 A. Ex~mples or such amylolyti~ erlzymes are ~mylolytlc enzymes pr~duce~ an~ d.istributed under the trade nam~ o~
15 S0-~5~ or Termamyl~lD by Novo Indus~ri AJS~ C:openhage~, Denmark. Th~3se amylolytic en~y~nes are generally presented as granules and may ha~e enzyme activitie~ oP from about 2 t~ 10 Maltose units~milJ.igram.

20 The amylolytic ac~ivity can be determined by the metho~ a~;
described ~ P. Bern~ld in "M~ d o~ Enzymolo~y", V~l. I
(1955), page 149.

~h~ cor~posl~ion o~ the~ invention p~ x ably also cc)ntains a 25 proteQlytic enzyme~

Examples o~ suitable proteolytic enzymes ~re the sub~ilisins whlch ~re ~tairle~ ~rom particulA~ st~Ains o~
B. ~u~tilis and s. lich~ni~ormi~, suc~ ~s the commer~ially available subtilisins ~ax~ta~ supplied by Gis~-Brocades N.V., Delft, ~oll~n~, ~n~ Alcalase~, suppli~d by No~o IndUstri A/S, ~openh~gen, Denmark.
,~
Particularly ~;uitabl~ i:; a protease obtained ~rom z~ CrRin o~ Bacillus havlng m~ximum activity through~ut the p~ r~n~e 0~ ~-12, being ~ommercially a~ ro~ ~ovo Indu~tri , ' ~ ' ' , ' ' ',, . ' . ' ' - ~ ' ' , ' :
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~ 7284 (R) ~ ~ 7 ~
A/S unde~ the registered trade names of Esp~ase~ and Savina~se~. The preparation of ~hese and analogous enzyme~
is de~çribed in ~r~tis~ Paten~ Specification N~ 1,243,784.

Another suitabl~ ~r~a~ u~ul h~r~i~ i9 a t~irly roc~nt commercial produ~t ~old by Novo rndustri A/S under th~
trade nam~ Durazym~, as described in WO-A-&9tO6279. The enzyme~ ~an be presented as ~ranules, e.g. m~u~ , p~
~ granules etc., and may h~ve enzyme ac~ivit~es of from about 50Q to 1700 glycine units/miiligra~. ~he proteolytic actlvity can be determin~ by the method as de~crlbed ~y M.L.Anson in ~Journal o~ General Physiology", Vol. ~2 (1~38~, page 79 (one ~nson unit/g ~ 733 Gly~ine Units/milligra~. Por conv~nlent re~sons enzyme preparations, are also ~ommercially supplied a3 liquids or slu~ries e.g. ~ermamyl 300 L, Savinase 16.0 L, Sav~na~
16.0 SL.

All the~o enzyme6 can e~ch be present ~n a weight perC~ntage amount of frum 0. 2 to 5~ by weight, such ~ha~
fo~ a~ylolytic enzyme~ ~he ~inal compo~i~ion will have amyloly~lG activi~y o~ ~rom 1o2 tu 1o6 Maltose uni~s/kg, ~nd for proteolytic en~y~es tne ~inal composition will have proteo~y~c enz~me a~ivity of from lo6 ~o 109 ~lycine `` 25 Units~kg.

Enzyme granules containi~g only minor propor~ion6, e.g.
less than 30%, particularly not m~r~ t~an lG~ by weight, of chloride ~o substantially nil, ~re pre~erably u~ed in the ccmposi~ions oP the inYention.

The En~a~s~ ed_Blea~h Particles.
Enca~ula~ion ~echniques are ~nown ~o~ bot~ peroXygen and chlorlne bleaches. US ~atent Spe~flca~ion N~ 4,1~,5~3 to J~hns~on, ~or e~mpl~, ~hows the en~psulation oP a peroxyacid bl~ach w~th ~ wate~-~oluble sur~actant c~pou~d.

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9 2 ~ 7 ~everal pa~ents teach the use of coa~inys derived from fat~y acids, su~h as US P~ent N 4,327,151 to Mazzola, which di~closes an encap~ulated ble~ching agent having an inner coa~ing of a fa~ty acid and a microcryst~lline wax, and an outer coating of a fat~y acid and P~uronic surfactant6, and US Paten~ ~ 3,~83,254 ~o ~lterman, w~ich shows a method o encapsula~in~ ~leaching agents with fat~y acids and alkali metal ~alts o~ f~ty a~ids. Other encapsulated bleaches are al60 ~nown. ~or example, US
~0 Patent N~ 4,279,764 to Bruba~er shows encapsula~ion of a miXture o~ an organic nitrogen-containing halogen bleaching agent; an ~-H-con~a.ining comp~und, and a soluble inorganic hydxa~able salt~ US Pate~ 3,~3~,013 ~o Jas2~a tca~hee encapsulated calclu~ ~ypochlo~i~e bleach.
The coatings can be appli~d in a varie~y of woll-known methods including tumbling the coating and coa~ed compound in a rolling mill, spraying a solution or suspension o~ the coating into a fluidi2~ ~ed of the compound to be ~oated, precipitating the ~oa~is~g ~rom a ~olvent on to the compound to be coate~ which is in suspension in the ~olven~, etc.

In the last few year~, encapsulation ~echnology ha~ so ~, progressed t~at Ghlorine or peroxygen bleach encapsulates o~ excellent s~ability can be produced. one o these improved tec~nologies uses a wax c~atin~ and i~ described in ~-A-0,436,971 and in ~pplicant's co-pending Europcan Patent Applica~ion ~ ~2201091.3. The proble~, howevcr, i~
that even a slight leakaye w~uld lead ~o enzyme d~radation a~ explained before.

Still, a pre~erred encapsulate~ ~each p~rticle for u~e in -the pxesent inven~ion .is that ~ des~rlbed .in tho above mentioned European patent ~pplioations, comprising 35~5$S
by weight of the par~icle of a ~1ngl~ coat o~ p~ra~ln W~X
and 45-6~ by ~ei~ht of a ~o~e o~ a chlorine or p~roxy~n , ,, , o ~ ~ 7 ~ ~ ~ 7 bleach compoun~, the paraffin wax having a melting p~int of between 35~C and about ~50~, prefera~ly ~om 40~ ~o 50C, and h~ving penetration values of from 10 to 60 mm at 2s~c, The bleach t~ be encapsulated in t~e co3tin~ may be a chlo~ine- or bromine-releasing ayent or a peroxygen compound. Among suitabl~ reactive chlorine- or bromine-oxidizing materials are heterocyclic N-bromo and M-chloro imides suc~ a~ ~richloroisocyanuric, tribromoi~ooyanuric, dibromoisocyanuric and dichloroisocyanuric acids, ~nd salts thereof wit~ wate~-sulubilizing ca~ions such a3 potassium and ~o~ium. H~dantoill compounds such as ~,3-dichloro-5,5-dimetfiyl-~ydantoin a~e also ~uite suitable.

Dry, particulate, ~ater-solubl~ anhydrous inorganic 6al~s are likewi~e suitable for use herein such a~ lithium, sodium or cal~iu~ hypochlori~e ~nd hypobromi~e. Chlorina~Qd trisodium phosphate is another core ma~rial.
Cllloroi60cyanurates are, however, th~ preerred bl~aching agents. Potassi~m dichloroi~ocyanurate is æold by Mon~anto Company as ACL-5~. Sodium ~ichloroisocyanurates ar~ al~o available from Monsan~o as ACL-60~, an~ in the dihydrate form, from ~he Olin Corporation as Clea~on CD~-56~, ava~ lable in powder ~o~m (partiole t3iameter of les~ k~an 150 m~crons); rnedium ~artiole size (about 50 to 400 ~mlcrons); and coarse particle si~e ~150~850 miCrQnS). Very large par~ les (~0-1700 micrGns;) a~e 21lso found ~o be suitable for encapsulation.

Organic peroxy acids or t~e ~re~ursor~ therefor may also be u~ilized as the bleach eore. The peroxyacids usable in ~he present invention are solid an~, preferably, sub~nti~lly water-insolubre c~mp~un~ . ~y "su~stanti~lly water~
insoluble" is meant her~in ~ watex solubility oS le~ than 35 abou~c ~g6 by weigh~ at ambient ~emp~r~ure. ~n g~ner~l, peroxyacids con~alninq at l~ast about 7 c~rl::on a'coms ~rs - :
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ll 2~81~7 ~ 7~4 (~

~Ur~ic~iently insoluble in watex for use herein.

Typlc~l monoperoxy acid~ useful ~erein inclùde alky~ peroxy ~cidS and aryl peroxyacids such as:
S
( i) peroxybenzoic acid and ring-substi~uted peroxybenzoic acids, e.~. peroxy-alph~-naphthoic acid;
~ ii) ali~hatic and subs~ituted ~lipha~ic monop~roxy acid~, e.g. peroxylauric acid and per~xysteari~ acid;
lo(iii) phthaloyl dmido peroxy capxoic acid (PAP~.

; Typical diperoxy acids useful herein include alkyl dip~roxy acids~and aryldiperox~ acid~, ~uch a-~:
(iv) 1,12-diperoxydod~nedioic a~id (DPDA);
~5( v~ l~9-diperoxy~zelaio acid, (vi) dipexoxybrassylic a~id; diperoxyseb~cic ~cid and dipexoxyisophthalia acid;
(vii) 2-d~yl~iperoxybutalle-1,4-dioic aa~d.

Peroxyacid bleach precursors are well know~ in the art.
non-limitin~ example~ can be named N,~,N' ,N'-~e~xaacetyl ethylene di~min~ tTAED), s~dium nonano~loxybenzene sulphonate (SNOBs), sodiu~ ~enæoyloxybenzene sulpho~atc (S~OBS~ and the eationic peroxyaci~ precurso~ (SPCC) as desc~bed i~ US Patent Speci~icatioh ~,751,015.

Inorganic peroxygen-generating compounds may also ~e suitable as cores for the par~icles of th~ present inven~ion. Exa~ple~ of these materials are salts of 30 monopersulphate, perbora~e monohydrate, perboratc te~rahydrate, and percarbonate.

If desirably a~bleach cataly.s~, such as the manqane9e complex, e.~. Mn~Me TAC~, as d~s~ibed in EP~-04583~7, or t~e sulphonimines o~ VS P~tent~ S,0~ 32 and 5,04~ 3, is to be incorporated, ~his oan ~e pre~ented in the ~or~ o~ ~

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12 ~ 7C 72~4 (~) second encap~ulate separ~ely from the ~leach ~apsule.

For c~lori~e ble~ohes th~ amoun~ of encap~ulate~ ~sed in the composi~ions o~ the inv~ntion may vary w~thin the xange of about 0.5% to a~ut 3% a~ avail~ble chlorine (AVC1) .
For peroxygen bleaching ~gen~ a sui~able rang~ will be ~rom 0.5% to 3% avo (avail~blc oxygen) .

The Reducinq Aqent Reducing agents useful to ~revent the appearance of an enzyme-deactivating concentr~tion o~ oxidant bleach co;mp~und includQ reducing agent ~ha~ can substantially reduce C12, HClo and other oxidizing chlorine-contain~ng compositions to Cl- ions or can ~ubstan~ially redu~
~5 hydrogen peroxide or peroxy ~cid bleaches to unoxidized species. The reducin~ agent should not damage the obje~t or ma~erial to be cleaned or substan~aally chemically change the enzyme, or other cleaning aomposition component~ such as the dete~gen~, builder, etc.
Useful reducing agen~s include re~uci~g sulphur-oxy ~cid~
and salts ~hereo~. Most preferred for rea~on~ o~
availability, low cost, ~n~ high performance ar~ the alkali metal and ammonium salt~ Or sulE~huroxy acid~ incl~ding 25 ~mmonium sulphite ( (N~")2$03), sodium sulphite (Na2503), sodium bàsulphite (NaHso3), sc~ùium metabisulphite (~a2S203), potassiu~ ta~isulphite (~S205), lithium hydrosulphite (Li2S20q), etc~, ~sodium sulphite beinq particulArly pr~ferred.
Anoth~ar usef ul reducin~ agent, th~ugh not partic:ularly preferr~d for reasons c:>f C05t scorbia a~id. Thoso re~u~ing agent.~ mu~t ~e used at su~ficient a~ount~
ef~c~ive ~o scavenge the chlo~ine or oxidiz~ng bleach le~age. It will be appreciated tha~ these ~moun~s may vary ~rom ~se to case depen~ing on the typ~ ~nd quality ~f the .
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encap~ h.l~r.h p~rtiel~s, but ~ r~ ral~y~ ~L
about 0 01~ to about 0.5~ by weight, pre~erably from about 0.02~rto about ~.2% by weight, will be sufficient, An amou~t lowe~ than 0.01~ may no~ be effec~ive and an amount hi~her than 0.5~ m~y no~. he ne~essary and, b~ide~, in th~
~aee nf ~odl~m ~u~ph;to, is not w~nt~ uYe o~ lts sm~ll.

O~io~al In~redients Optional in~redient.~ are, for ~xamplc, ~he well-~nown enzyme ~tabilizer~ such ~s ~he polyalcohols, e.g. glycerol, ~n~ ax; anti-s~aliny agents; crysta~-growth inhibito~s, thresfiold agents; thicke~ing agents; per~es and dyes~uffs and the like.
A small ~mount of low- to non-foa~ing nonionic surfaGtant, which includes ~n~ alkoxylated nonionic su~aoe-a~ e agent wherein the alkoxy ~oiety is selected ~ro~ the yroup consisting of ethylene oxide, propylene oxide and mixture~
thereof, is preferably used to improve the deter~enc~ and t.o suppress exces~ive goaming du~ to some pro~in scil.
How~ver, an ex~essive proportion o~ nonionic s~rfactan~
should be avoided. Normally, an amount ~f 0.1 to 7~ by ~igh~,~ pref~ra~l~ f~om 0.5 to 5~ by weig~t, is quite suffieient.

Examples of suitable nonionic surfactants ~or use in the inv~ntion ar~ the low- to non-foaming ethoxylated propoxylated straig~t~chain al~ohols of the Plura~ac~ RA
serie~, supplied by the Eur~ne Company; o~ the Lutensol~ L~
seri~s, suppli~d b~ the BasF ~ompany; o~ ~he TritonO DF
series, supplled by the Rohm & Haas ~ompany; and Synperonio.s, suppli~ ~y th~ .L Comp~ny.

3~ Ano~her option~l but highly desirable additive ingredient with multi-~unctional char~cteristics, particularly ln non-. ,- .,"' . '- ' . ' ' '" ` "' ,"' " ' :
. ` ,, . ~ : . ' , .
~,,. "',, `. ' C 7284 (R) ~7~1~7 phosph~te compositions, i.~; from 1% to 15%, pref~rably ~bout 59~ by weight, of a poly~ne~ ; material h~ving a molecular weight~ of ~rom 1, 000 to 2, 000,000, and ~hich can be a homo-or co-polymer of ac~ ic aci~l, maleic acid, or salt or 5 anhyd~ide thereof, vinyl pyrrolidone methyl- or ethyl-, vinyl ethe~s and ot]~er polymerizable vinyl monomers.
Pre~erred ~xamples of such po~ymerlc ma~eri~ls are polyaGrylic acid or polya~rylate; polymaleic acid o~
polyacrylate; polymaleic aGid/clcrylic acid copolymer; 70:30 o ~crylic acid/hydroe~hyl maleate copolyme~
st~ren~m~leic acid copolymer; isobutylene/maleic acid and diisobutylene/maleic acid copol~m~rs; methyl- and ~thylvinyletherJmaleio acid copol~vmer~; ethyl~ne/malei~
acid copolymer; polyvinyl pyrrolidone, and vinyl pyrrolidon~maleic aci~ copolymer. These polymers are believed ~o func~ion aS ~o-builders, althou~h under certain conditions they may als~ function ~s main builders.

~he comp~sitions oP the present invention may a~so co~prise, and preerably ~, a thicke~2r, ~or example, a polym~r such as a suitable ~rylat~, ~ethacryla~e (or co-p~lymer thQreoS) or a cellulo~e such as hydroxymethyl cellulose. Typi~al inclusion lcvels o~ thic~ener are ~rom 0.1% t~ 10%, e.g. from 0.5% to 5% by weight o~ the total 25 compo~tion .

Buf~ering agents may alsc) be necessa~y to adjust and main~ain the alkalinity and pH of t~e composition ~t th~
desi~ed level. These are, for example, the alkali metal oar~onate~, bicarbona~es ~nd bo~ates. Also sodium and/or po~a~sium hydroxide may be usQd.

ThQ invention may be more rully understood by w~y ~f th~
~oll~win~ illustrat~ng ~x~mples.

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C 72~4 (~) 15 ~7~7 XAMPL~_I

Th~ f~llowlng aqueous liquid alltomatic ~ishwashing composition was prepared:

COr~POB ' tion_I ~k~
Ca~bc,pol~ 941 1. 50 NaOH ~pellets) ~ . 80 Borax 3, 0~
10 Glycerol 6 . 00 Polymer (Sokalan~ CP'7) 5.00 Sodium citra~ 30. 00 Sodiun~ sulphite 0. 04 ~hlo~ e blea~h ca~sules :l) 4 . 30 15 Proteol~tic enzyme (Savinase 3' 16. OL) O. 30 Amylase (~ermamyl ED 3 00 L) O . 3 D
Water tolOP. 00 ~abt. 499~) .

1~ The chlorine bleac~l ~aE)sules used herein aomprise 20 about 50% of Na-DCC7A c:ore ahd 50% oP~ a para~Pin wax coa~ing~ giving approx. 1,20% avC10 (see EP-A-0,436,971).

To aim for maximum enz~me ac~ivity directly afte~
complet:ing the processing steps, khe ord~r of addition 25 during manu~acture should be t~at the sodiuJn sulphite i~;
add~d as nea~ as po :3ible to the ~ddition of the bleach encaps~la~ion and definitely k~efore the enzyme~;.

Enzyme stability o~ the composi.~ion is quite satisPactory.
When a similar compo:~ition was prepared containing 20% o~
s~diu~n c~trate, resulting in a water content of approximately 5gg~ by weight, ~ substan~ial decrease of enzyme: sta~ility w~s observed.
~5 .,' , . ',:
. , . :
.

. ., lG 2 ~ 7 ~ C 72~4 (R) Compo ition I was tested in a Mie:Le 595SC dishwashing machin~ at a tempe~-ature of 55 DC~ using water o~ 14 FH .

The cleaning results ~ompared wi~h the commerci~l Dutch 5 products "S~n" Li~auid and "Surl-Prog:~ess" are tabula'ced below .

-.. ..

- , :

1/ 2~7~:L57 7284 (R) ~2~H___ Sun LiquidSurl-Progress Composition I

Porcelain pla~es - potato 7 5 2 12 - custard 75 69 39 - spina ::h 0 Steel plates - potato 8 2 1 - custard g~ 72 a2 Potato pan - ~o~tom 6~ 7 2~
- ~im 78 18 27 average 73 12 27 ~usta~d spoon50 17 30 Lip~t i ck ~ cup 1.1 3.~ 1.7 - tumbler ~. . 2 3 . 7 1. 6 ave~age 1.1 3 . 7 1. 6 E~g ~ork 1.2 ~ .1 1,4 ~ilk Glas~ 1. 0 1. 0 1. n Bleach ~ ng . 2 ) 2 5 Tea - ~ups ;~. O 1.0 1.~ I
- saucers 1.0 1.0 1.0 ¦
- spoon:; 1.1 1.1 1.3 ¦
average 1.0 ~.0 1~ ¦
Cof~e~3 1 - CUp8 1 . ~ 1 . 0 l ~J

3 5 - ~ea~ureJn~ntS
- p~ mai~ wash 11. 0 10~ ~ 8 . 5 c ~2~4 (R) 7~37 - pH f inal rin~e ~nd 9 . 3 9 . ~ 8 . 7 ~ F~, Permanent 1~ 16.1 16.7 - F~r ~emporary 4 . 75.1 4 . 2 5 1~ Re~idual Soil (~) 2) 4 point scale. 1-Complete removal, 4 No removal at all EX~MPLE ~ I I

he o~ec~ of v~ryi~l~ tl~c nominal water content on savinase and Amylase storage stability (in ~) in a mechanl~al dishw~:~hin~ l iquid o~ ba3e ~o1 m~ ion given in Exampl~ I
is shown in ~igur~s 1 and 2, respec~iv~ly.

:15 Fig. 1 - ~he residu~71 activity (9~) o:~ Savinase on th~
vertical axis is plotted ayainst the nominal water content (9c by weight) of the liquid product ~fter S.5 weeks' storag~ at room temperature t +) and at 37 ~

~i~. 2 - The residual activity (~) oi~ P~ny~ase ~n the vertic~l axis is plotted against the nominal water cont~nt (% by weight) of t:he li~uid proc~uct after 5.~ weeks' storage ~t ro~lT temperature (~) and at 37C ~).

~h~ ~l~u:r~s show clear imp~ov~lne~t o~ enzyme stor~ge stabili1:y in ~ompositions containing less than 55% water.
Especislly Fig. 1 shows the dramatic: drops of Savinase residual activi'cy in c:omposi~ions c~ntaining more ~han 559 water .

~ .
.
: . , ,, ~
, ~ '. ~ ' .
.
, ~ . .

c 72~4 (}~) q~hree aquec;~us li~uid cleanin4 compositions co~nprising the ~ollowj ng ing~edients ~lere prepared with varying amount~ of sulphlte.

5 Co po6itiQn III % by hTeight Ca~bopol~ 941 1. 50 NaO~ pellets 0. ~0 BoraX
Glycerol 6.00 10 Polymer (sokalan~ ~P7)5.00 Sodium citrate 30.50 sodiu~ sulpl~ 0.00 - 0.04 - 0.10 ~PS b;ea~h capsules ~.) 5.00 Proteolytic enzyme (Savinase ~ 16.0~) 0.30 15 Amyla~e (TermamylG~ 300 L~ 0. 30 Water to 100~00 (approx. 4J%).

1) The MPS bleac~ cap~ules used herein are encaps~lateE comp~ising po~assium monopexsulphate ~50% by weiqht) as th~ core bleac~ ~aterial provided with 50% by weight o~ a para~n wax coating And p~epared acco~din~ to the method as descri~ed in EP-A~0,436,9~1.

These ~ompositions were stor~d ~or 6 weeks at 37~C, " 25 where~fter the resid~al ~Ctivities o~ Savinase and Te~amyl we~e determined.

Savin~ residual activity (~
with 0.00~ sulphite = 30 30 with 0. 04% sulphite ~- ~0%
W~th 0.10~ sulphite = 75~

~mylase ~e~amyll resi~ual activity (~) wl~h 0.00% sulphite - ~%

... ...
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- ~

c ~7 2 8 4 ( ~() 2~7~ ~7 with 0.04-~ sulphite = 9.5 wi~h 0.10~ sulphite = 95~

TheQe r~sults ~emonstra~e ~ha~ low water level alone does no~ result in enzyme storage stability and that even ~t water level below ~5% ~he pres~nce of sulphite is essential.

EX~MPL~ ~v _ _.

This Example shows en~me s~ability as a ~unction o~
sulphite level in al~ accelerated storage test. The exp~rlments were ~arried out with the formulations o~
Example ~ with varying lev~ls of sodium sulphite. The compositio~s were stored at 50~C for ~ hours. ~he results are tabulated b~low.

Sulphi~e ~evel (%~ ~sidua~ Ac~tivity L~l sa~inase Amylase 0.02 4 5 `
0.04 .~ 7.~
o.1n 30 3~5 .20 6~ 8205 . . ,

Claims (9)

1. Aqueous liquid cleaning composition comprising a detergency builder, an enzyme, encapsulated bleach particles and a reducing agent, characterized in that the composition has a water content of not more than 55% by weight and the reducing agent is present in an amount of from 0.01 to 0.5% by weight.

2. A composition according to Claim 1, characterized in that said water content is not more than 50% by weight.

3. A composition according to Claim 1, characterized in that the amount of reducing agent is form 0.02 to 0.2% by weight.

4. A composition according to Claim 1, characterized in that it has pH of from about 5.0 to 10.5.

5. A composition according to Claim 1, characterized in that the reducing agent is sodium sulphite.

6. A composition according to Claim 1, characterized in that it comprises an amylolytic enzyme.

7. A composition according to Claim 1, characterized in that it comprises a proteolytic enzyme.

8. A composition according to Claim 1, characterized in that it comprises a misture of amylolytic and proteolytic enzymes.

9. A composition according to Claim 1 and substantially as described herein.