CA1204646A - Gel-type automatic dishwasher compositions having thixotropic properties - Google Patents

Abstract

GEL-TYPE AUTOMATIC DISHWASHER COMPOSITIONS
HAVING THIXOTROPIC PROPERTIES

An aqueous thixotropic automatic dishwasher composition containing alkali metal tripolyphosphate, sodium silicate, alkali metal carbonate (preferably), bleach-stable surfactant, sodium hypochlorite, higher alkyl acid phosphate ester foam suppressor, clay thickener, and sufficient caustic soda to provide a pH of 10.5 to about 13.5.

Description

GEL-TYPE ~UTOM~TIC DISHWASHEP~ COM_ SITIONS
HAVING THIXOTROPIC PROPERTIES
The invention relates to automatic clishwashing detergen-t composit:Lons hav:Lng thixotroplc properties, improved chemical and physical stability, and which are readily dispersible :Ln the washing medium to provide effective cleaning of dishware, glassware? china and the like.
Commercially available household-machine dishwasher detergent provided in powder form has several disadvantages, e.g., non-uniform composition; costly operations necessary in their manufacture; tendency to cake at high humidities, resulting in the Eormation of lumps difficult to disperse, and dustiness, a source of particular irritation to users who suffer a:Llergies. Liquid forms of such compositions, moreover, generally cannot be used in automatic dishwashers due to high Eoam leve:Ls, unaccept-ably low viscosities and exceedingly high a:Lkalinity.
Recent research and development activity has Eocussed on the gel or "thixotropic" Eorm oE such compositions, e.g., scouring cleansers and automatic-dishwasher products characterized as thixotropic pastes. Dish-washer products so provided are primarily objectionable in that they are insufficiently v:Lscous to remain "anchored" in the dispenser cup of the dishwastler, and moreover yield spotty residues on dishware, glassware, china and the like. Ideally, thixotropic cleansing compositions should be highly viscous in a quiescent state, Bingham plastic in nature, and have relatively high yield values. When subjected to shear stresses, however, such as being shaken in a container or squeezed through an orifice, they should quickly Eluidize and, upon cessation of the applied shear stress, quickly revert to the high viscosity/Bingham plastic state. Stability is likewise of primary importance, i.e., there should be no significant evidence of phase separation or leaking after long standing.

~J~

~1 lZU46i6 ll'he pl~ovision Or ~utoll~at:Lc-dishwasher compositisnD in ItCJ
form having the arorede cribed properties has thus far proved problematical ~ particulBrly BS regards compositions for use in home di~hwa~her machine~. For errective use 9 it i5 general].y re-commended that tha automatic dishw~shing detergent, hereinafteralso designated ADD, contain ~l) sodium tripolyphospha~e (Na~rP~
; to soften or tie up hard-~ater minerals and to emulsify and/or peptlæe soil; (2) sodium silicate to supply the alkalini-ty necessary for e~fective detergency and to provide protection for .. 10 fine china glsze and pattern; (3) sodium carbonate, generally considered to be optional, to enhance alk~linity; (4) a chlorine-releasing agent to sid in the eliminatio~n of soil specks which lead to water spotting; and (5) defoamer/surfactant to reduce foam, thereby enhancing machine efficiency and supply requisite deter-gency. See, ~or example, SDA Detergents in Depth, "FormulQtionsAspects of Machine Dishwashing," Thomas Oberle (1974). Cleansers approximating the aforedescribed composition are mostly liquid3 or powders. Combining such ingredients in a gel form effectire for home-machine use has proved di~ficult. 6enerally, such com~osi tions omit h~pochlorite bleach, since it tends to react with other chemically QctiVe ingredients, particularly surfactant, thereb~
de~rading the suspending or thixotropic agent and impairing its . effectiveness. Thus9 U. S. Pat. No. 4,115,308 discloses thixo-tropic automatic dish~asher pastes containing a suspending agent, e.g~, CMC, sy~thetic clays or -the like; inorganic salts including sil~cates9 phosphates, polyphosphates, etc., a small amount of sur~actant snd a suds depressor. Bleach is not disclosc~. U.S.
Patc ~o. 4,1~79650 i~ similar and rurther includes a hypochlorite bleach. The product is described, howe~er, as a detergent slurry.
3o U.S. Pat. No. 3,985,668 describes abrssive scouriD~ cleaners . I
. o~ ~el like consistency conL.I~n~n~ (1) su~petlding ~ent, ~rcl'cr- ¦
ably the smectite and attapulgite types o~` the colloid forming clays~ (2) abrasive, e.g., silica sand or perlite; and (3) filler comprising light denslty powdered polymers, expanded perlite and the like, which has a buoyancy and thus st;sbilizing effect on the composition in addition ~o serving as a bul~ine a~ent, th~reby replaclng water otherwise available for undesired supernatant layer form~tion due to leaking and phase destabilization. The foregoing are the esse~tial ingredients. 0ptionsls include hypo-chlori~e bleach~ bleach stable surfactant ~nd buff~r, e.g.,silic~tes, carbonates, monophosphate~, e~tc. Builder such as NaTPP
can be included as a further optional to suppIy or supplement building function not provided by the buffer', the amount Or 5uch builder not e~ceeding 5% of the total composition, according to the patent. Maintenance of the desired >~10 levels is enabled by the buffer/builder components. High pH is said to minimize decomposition of chlorine bleach and undesired interaction betwcen surfactant and bleach. When present, Na~PP is limited to 5%, as stated. Foam killer is not disclosed.
~ In accordance with the invention, it has been discoverea that improved de,tergen-t compositions particularly adapted for use i~ automatic dishwashers, particularly those of the type found in , the home ~ Rre provided having t'he properties desirably character-i7.ing thixotropic 9 gel-type struc-ture and including each o~ the VariOUS ingredients necessary for effective detergency within such automatic dishwaeher~
Thus, a prirnary ob~,ec-t of the invention is to provide a detergent composition having thixotropic properties and benefici- , ally adapted ~or use in an automatic dishwasher.
A l'urther obJect of the invention i~ to provide such n ~2~

composition having good physical stability with no significant phase separa-tion being evident after prolonged periods of standing.
Anotller object of the invention is to provide such a composition wherein problems associated wi-th undesired intelac-tion of chemically active ingredients are eliminated or at least substantially mitigated.
Yet another object of the invention is to provide such a composi-tion having the aforementioned stability under the highly alkaline conditions necessary for effective detergent performance.
Still another object of the invention is to provide such a com-position having improved rheological properties exhibiting higher viscosities at low shear rates and lower viscosities at high shear rates--thus advan-tageously adapted for use in the dispenser cup of automatic dishwashing machines.
Yet a f~rther object of tlle invention is to provide such a com-position having low foam characteristics, improved detergency and being readily dispersible in the washing machine.
Other objects and advantages of the invention will become apparent hereinafter.
The foregoing objects are a-ttained in accordance with the invention which in its broader aspects provides a normally gel-like aqueous automatic dishwasher-detergent composition having thixotropic properties comprising, by weight, from about: (a) 5 to 35% water-soluble alkali metal tripolyphos-phate having an average degree of hydration of from about 1 to 5; (b) 2.5 to 20% sodium silicate; (c) 0 to 9% water-soluble alkali metal carbonate;
(d) .1 to 5% bleach stable, dispersible organic surfactant; (e) .1 to .5%
mono- and/or di-(C16-C18`~ alkyl ester of phosphoric acid foam suppressor (depressor); (f) 3-20% NaOCl soln-13% avail. C1; (g) 1.5 to 10% inorganic, colloid-forming clay thickening agent; and (h) sufficient sodium hydroxide to provide a pH of 10.5 to about 13.5, the amount of phosphoric acid ester being sufficient to provide low-foaming characteristics, the amount of sodium hydroxide being at least sufficient to neutralize said phosphoric acid ester, the composition having thixotropy inde~ o:E about 2.5 to 10.

Preferably, the weight ra-tio of suractant to foam suppressor is about 10 -to :l to 1 to l.
ADD compositions so formulatecl are low-foa.m:ing; stable, both chemi-cally and physically, a:re readily soluble in the washing medium ancl most effective at pll values best conducive to improved cleaning performance, viz, pH 10.5-13.5. The compositions are normally of gel consistency, i.e., a highly viscous, opaque jelly-like material having Bingham plastic character and thus relatively high yield values. Accordingly a definite shear force is necessary to initiate or increase flow, such as would obtain within the agitated dispenser cup of an energized automatic dishwasher. Under such con-ditions, the composition is quickly fluidized and easily dispersed. ~hen the shear force is discontinued, the fluid compos:ition quickly reverts to a high viscosity, Bingham plastic state, close:ly approxi.mating its ~prio:r consistency.
Generally, ADD effectiveness is direct].y related to (a) available chlorine levels; (b) alkalinity; (c) solubility in washing medium; and (d) defoamer efficacy important herein that the pH of the ADD composition be from about 10.5-13.5 and preferably at least about 11.5. The use o~ NaOH
herein is thus essential, since without NaOH, the ADD pH is below 10.5. At this pH, the ADD product is too viscous, i.e., solid-li.ke, and thus not readily fluidized under the shear-force levels created within the dispenser cup unc!er normal machine-operating conditions. In essence, the compositi.on loses much, if not all, of its thixotropic character. In that case, addition of NaOH is thus essential to increase pH and flowability properties. The presence of carbonate is often needed herein, since it acts as a buffer enabling maintenance of the necessary pH level. Excess carbonate is to be avoided, however since it may cause the formation of needle-like crystals of carbonate, thereby impairing the stability and/or I l;Z~ 6f~
I ~ ' I
unctlonn~lly Or tl~e ~ pr~duct, ~ e c~ustic so~ servcs tlle ¦~urther vital ~unction Or neutrslizing the phosphoric acid ester oam depre6sor.
l Other criteria governing ingredien~ selection herein an~
5 ¦e~ential to providin~ a st~b:Le, e~fectlve ADD product havin~
thixotropic proparti.es are as rOllow8 The NaTPP must be free Or ¦ heavy metal, since the latter tcnds ~o decompose the soaium hypo-¦chlorite. On avera~e, ~he NaTPP contains a~out 5-15% by ~eight ¦ water, corresponding to an average degree o~ hydration of about 10 ¦ 1 to 5. If only the hexahydrate is used, the detergent product ¦ is liquid and has little if any thixotropic character~ If only ¦ the anhydrous ~aTPP .is used, the product~is too thick ~nd therefore unsuitable. Effecti~e compositions obtain, for example, l using a O . 5 :1 to 2 :1 weight ratio of anhydrous to hexahydrated NaTPP, values of` about 1:1 being particularly pre~erred. Foam depressor is essential to increase dishwasher-machine efficiency and to diminish destabili~ing effects which ~ight occur due to the presence of excess foam within the washer during use. Available chlorine levels are supplied herein by sodium hypochlorite ra-ther than, for example, the dichloroisocyanurates used in current powder detergents.
The ADD product exhibits improved rheologi.cal properties as e~alua-ted by testine product viscosity as a ~unction o~ shear rate. In~estieation)eonfirms the compositions to exhibit highèr viscosity at a low shear rate and lower viscosity at a high shear rate the data indicating erficient fluidization and gella~ion well I
within the shear rates extant within the dishwasher machine~ In . practical terms, this means improved pouring and processing charac-teristics as well as less leaking in the ma~hine dispenser-cup, compared to current . liquid ADD products. ~or applied shear ~ 6 rate5 ,o~respondfng ~ 3_t~ 3'0 rpm~ vlscqsi~iPS (~rq~ k- ~
~ield)correspondingly range rrom about 15,000-~7000 cps to a'bou~ j 300~-5000 cps"as mPasured at room temperature by means Or an LVT
Brookfield viscosimeter a~tPr 3 minutes using a ~ spindle. A
shear rate Or 7. 4 sec~l ~orresponds to B spindle rpm of about 3.
~n appro~imate ten~f'old increase in shear r~-te produces a six- to seven rold reductiorl in ~i5Cos~ty. With current ADD gels, -the corresponding reduction in ~iscosity is on:Ly about two-fold.
Moreover, with such compositions, ~he initial viscosity taken at about 3 rpm is only ~bout 2500-2700 cps. The instant compositions thus exhibit threshold ~luidizations at lower shear rates and of significantly greater e~tent in terms of~incremental increases in shear rate vs. incremental decre~se in viscosity. This property of the in~tant ADD products ls summariYed in terms o:~ a thixotropic index (r~I) which mea~ures t'he ratio of (a) apparent viscosity at 3 rpm to ~b) apparent viscosity at 30 rp~n. The present composi-tions have a TI of from about2.5 to 10 and pre~erably 6 to 8.
Each of the ADD compositions tested exhibited subs-tantial and quick return to prior quiescent state consistency when the shear ~orce is discontinued.
In preparing the ~DD pro~uct, one should dissolve or disperse first all the inorganic salts, i.e., carbonate, siiicate and tri-polyphosphate, in the a~ueous medium. Thickening agent is added last. The phosphoric acid ester foam depressor i5 preliminarily provided ~s an aqueous dispersion, as is the thickening agent.
The ester dispersion~ caustic soda and inorgsnic salts are first mixcd at elev~te(l tcmperature~ in aqucou3 solution (dcioni~c~l water) and thereafter cooled, using agitation throughout.
Bleach7 sur~actant and thickener dispersion at room temperature 3o sre thereafter added to the cooled (25~35C.) solution. 'rhc ~ 7 * Trade Mark amount of t~ter used i~ such a~ to proYlde sn ~ oncentrntl~n in the A~D produr~ of from alout ~5-75~, a r~nge of about 50-6577 ~ein~ pra~r-rod.
The illorganic salts herein comprise, by weight of total ¦ product, ~Ibout: ta) 5 -~o 35% an~ prcferably about 20 to 30% NaT~r;
il~b) 2.5 to 20~ and preferably about 10 to 15% sodium sll~cate hav ¦¦ing an Na~O:Si4 ratio of about 0.3 to 0.5%, and (c) 0 to 9%, pre-¦¦Eerably about 4 to 7%Jalkali metal carbona~e, preferably sodium !Icarbonate. These salts should provide a total salt concentration llof about 20 to 50% and preferably about 35 eO 45%.
Bleaching agent comprises sodium hypochlorite ~NaoCl) soln of ~3% avai~able Cl ln amounts of a~out 3-20~, preferably about 7-12%
Caustic soda, as mentioned, should be sufficient to malntain a pH o 10.5 to about 13.5 and preferably about 11.5 to about 12.7.
lS 1I Generally these amo~nts will be about 0.5 to ~%, and in any event ¦at least sufficient to neutrallze the foam depressor phosphoric ¦¦acid ester compound.
The preferred foam depressor comprises mono- and-or di-C16-~IclB alkyl esters of phosphoric acid in a range of about 0.1 to ,0.5% and preferably abou~ 0.15 to 0.3%, specific amounts depending in par~ on the quantity of surfactant present.
Sur~sctants useful herein must be stable in the presence of hypochlorite bleach and preferably comprlse those of the anionic, ¦amine oxide 9 phosphine oxide, sulfoxide and beta~ne types, the ~5 !former being most preferred. They are used in amounts ranging from about 0.1 to 5% and preferably about 0.3 to 0.8%. To ~nsure lladequate foam suppresslon, it is generally advisable to maintain ¦1a surfa~tant: foam-depressor weight ratio of about 10.1 to 1:1 land preerably about 1.5:1 to 4:1. Partlcularly preferred sur-30 1l f~c~ants herein 2re the linear or branched alkali metal mono-andJor dl- C8_14 alkyl diphenyl oxide mono- and/or dis-llfonates, l l ~4~6 i! :
,j . .
commercially avallable for example as DOWFAX 3B-2 and DOWFAX 2A-l.
'In general, the paraffin sulfonates tend to lmpair, if not des-troy !i thi~otropy, having baen found to unduly increase visc06ity causing 'severe shear~ng force problems. In addLtlon, the surEactant ¦ should be eompatible wlth the other ingredie~nts of the composi-tion. Othe~ suitable surfactants lnclude the prlmary alkyl- ;
sulphates, alkylsulphonates, alkylarylsulphonates and sec.-, alkylsulphates. Examples are sodium C10-Cl8 alkylsulphates such i! as sodium dodecylsulphate, sodi~lm tallow alcoholsulphate, sodlum Il C10-Cl~ ~lkanesulphonates, such as I sodlum hexadecyl-l--sulphonate; sodiu~ C12-C18 alkyl-! benzenesulphonates such as sodium dodecylbenzenesulphonate, and the corre~ponding potassium salts.
As o~her suitable suractants or detergents~ the amine oxide ¦sur~actants are typically of the structure ~ RlNO, in ~hich each ¦¦ R is a lower alkyl group, for instance methyl, and Rl is a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl~ palmityl or cetyl group. Instead of an amine 1 oxide, a corresponding surfactant phosphlne oxide R~R PO or sul-phoxlde RRlSO can be employed. Betaine surfactants are typically of the structure R2RlN-~R"C~O-, ln which each P~ is a lower alkyl li group, Rlis a long chain alkyl group as above and R is an alky`-¦¦ lene group having from 1 to 5 carbon atoms. Specific examples 5S ¦ of these surfactants are lauryl-dimethylamine oxide, myri~tydi-¦ methy.l.amine oxide~ cocodimethylamine oxide, hardened tallow ¦ dime~hyl amine oxide, the corresponding phosphine oxides and j sulphoxides, and the eorresponding betaines includ~ng dodecyldi-methylammonium acet~ate~ tetradecyl-diethylammonium pentanoate, hex~decyldime~hylammonium hexanoa~e and the li~ce. ~or biodegrad-ability3 the al}cyls in these surfactants should be linear, and are preferred.

_9_ ,__4 * Trade Mark ~-- l Surfactants of the foregoing type, all well known in thc llar~ are described, for example, in U.S. Patents 3~985,668 and l4,2719030.

Thicke~ing or suspending agents useful herein generally comprlse the inorg~n$c, collold-Eormlng clays of smec~ite and/or ¦attapulglt types, the ormer belng preferred. These materials ¦affect the rheological properties of the composit~on and are l¦used in amounts of from about 2.5 to 4~, the amount selected being i in any event sufficient to confer ~he desired Bingham plastic l~character. Smectite clays lnclude montmorillonite (bentonite), ¦!the preferred species, hector~te J saponite, and the like. Mater-l¦ials of this type are available under trade marks such as Thixogel I~No. 1 and Gelwhite GP from Georgia Kaolin Company (both being montmorilloni~e6) Attapulgite clays include the materials com-¦~mercially available under the trademark Attagel, i.e., Attagel 40, Attagel 50 and Attagel 150 from Engelhard Minerals and Chemicals l,C4rporation .
, Mixtures of s~ectite and attapulgite in weight ratios of 4:1 to 1:5 are use~ul herein.
9 Suspending agents of the foregoing type are well known in llthe Art, being described, for example, in the ref2rencsd V.S.
i!Patent No. 3,985,668.
85 1l Other ingredients useful in the instant ADD compositions ¦lnclude dyestuffs to provide a pleasantly colored composition.
¦¦Particularly preferred are the chlorinated phthalocyanines and jlpolysulfides o aluminosilicate which provide green and blue tints ¦respectively .
¦ The following examples are for illus~ration only, and are no~ to be considered as limiting the invention. Percentages herein are by weight and based on total product unless other~ise indicated.

ll ~2~641~ l Il ii Example I

A preliminary dispersion of foa~ suppressor, comprising a 12:1 mlx~ure oE mnno and dl-(016-C18) alkyl ester of phosphoric Acid, 0.16g, in 6g wa~er i6 prepared by mlxing at 60C. for 30 minutes us$ng a disk impeller. This dispersion is designated Part I.
l A preliminary dispersion of GELWHIT~ GP (hydration) ¦¦thickener, 3g ln 17g water, is prepared by m-lxing at 70C. for lO0 jjlO minutes uslng a Z-Bl~de mixer. This dispersion is designated Part 2.
The following ingredients are mlxed in a Giusti ~ixer at l50-60C:
1, % AI%
105 Deionized water ~
~I Par~ I 6.16 0.16 ,¦ Caustic soda sol.~, 49% NaOH 2.40 1.2 Sodium ca-rbonate 7.00 7.0 ;I Sodium silicate (1:2.4)soln~47.5% solids 13.74 6.5 llO ' Sodium TPP (substantially anhydrous)* 12.00 11.54 I Sodlum TPP (hexahydrate) 12.00 ~9.36 . .
,~ The mixture is cooled to 25-30C., maintaining agitation throughout, and ~he following ingredients at room temperature are ladded thereto:
il5 1I Sodium hypochlorite soln-13%available chlorlne 7.$15 1.0 I Part 2 (dispersed with highspeed turbine) 20.00 3.0 ! Oowfax 3B-2** 0.80 0.36 !1 *i.e., containing 0~5%~ specially 3%, moisture I **sodium monodecyl/didecyl disulfonated diphenyl oxide, 45% AI
Ii . .
!l -11-11 * Trade Mark ~o~ ~ An op~qu& co~positlon (about 4~~ ~I) having a gel-like conslstency ia obtain2d. The compo6itlon ls determlned to have ; a T:r oE about 7, according to the procedure hereinbefore described, based upon ~pparen~ vlscoslty values of 28~000 cps and 4,000 cps Il at 3 rpm and 3Q rpm respectively. When tested in an automatic 125 ! dlshwasher apparatus provlded w:ith a dispenser cup, the above composieion provldes e~cellent cleaning performance and is easily and qu-ickIy d-1spensed. The composition is observed to be satis-factorlly nonfoaming. Little vr no phase separation is observed a~ter prolonged standing in a closed container. The pH of the 13~ j c~omposition, measured as a 1% solution in water, is 11.6. When !I conducting the shear-test evaluations, it i9 observ~d that the ¦ composltion quickly reverts to its prior quiescent state consist-¦ ency, suggesting no appreciable loss of yield value when tested !1 within the limi~s hereinbefore described, i.e.~ wlthin shear-force 135 i limlting ~alues at least approximating those extant within an energized automatic dishwasher. No discernible difference ob-~ail1s when dispensing the ADD product by squeeze eube rather than d:l~penser cup.
I Example 1, illustrating a combined polyphosphate carbonate-140 jl silicate concentration of about 37% is repeated, but varying the ¦ total concentratlon o such salts wiehi~ the limits previously ¦ gi~en. Best results obtain at a combined~salt concentration o at least about 30% and particularly when the sodium tripolyphos-1 phate concentration is at least about 20%. Higher silicate l45 1 concentrat$onS,,desirable to protece china gla~e and patterns, alsoi~lpart hi~her alkalinity ~hi~h can be compensated for by appro-1 pria~ely xeducing ~he cau~ic soda concentr~tion and/or ad~ustin~
; ~he sodlum carbona~e (buffer) concentration. The composition 1 app~ars to be most sensit~ive, resultwise 9 to variations in the 15~ I NaTPP concentration (th0 hlgher concentration range is ~ore lj -12-effective) as well as its degree of hydration. Variations in surfactant con-centration generally require corresponding and direcl: variations in foam-suppressor concen-tration to achieve the desired low-foam levels.
Decrease o:E the composition p~l below about 10.5 is accompanied by significant decrease in composition effectiveness, as well as corresponding decrease of flowability.
Similar results are obtained when the procedure of Example 1 is repeated, but replacing corresponding ingredients wi~h alkyl sulfate surfac-tant, e.g., sodium coconut alkyl sul:Eate, attapulgite clay, e.g., Attagel 50;
and 2:1 mixture of montmorillonite and Attagel 50. The addition oE small amounts, e.g., 0.003-0.05% of chlorinated phthalocyanine and aluminosilicate dyes respectively to the Example 1 composition (included with the preliminary thickener dispersion or post-added to the cooled solut;on) produces pleasantly colored green and blue compositions respectively.
This invention has been disclosed with respect to preferred embodi-ments, and it will be understood that modifications and variation thereof obvious to those skilled in the art are to be included within the spirit and purview of this application and the scope of the appended claims.

Claims (13)

WHAT IS CLAIMED IS:

1. An aqueous automatic dishwasher composition comprising approximately by weight: (a) 5 to 35%, water-soluble axial metal tripolyphosphate having an average degree of hydration of about 1 to 5; (b) 2.5 to 20% sodium silicate; (c) 0 to 9%
water-soluble alkali metal carbonate; (d) 0.1 to 5% bleach stable, water-dispersible organic surfactant; (e) 0.1 to 0.5%
mono- and/or di- (16-C18) alkyl ester of phosphoric acid foam suppressor; (f) 3-20% NaOCl soln-13% avail. C1; (g) 1.5 to 10% inorganic, colloid-forming clay thickener; and (h) sufficient sodium hydroxide to provide a pH of 10.5 to about 13.5, the amount of phosphoric acid ester being sufficient to provide low-foaming characteristics, the amount of sodium hydroxide being at least sufficient to neutralize said phosphoric acid ester, the composition having thixotropy index of about 2.5 to 10.

2. A composition according to Claim 1 wherein the weight ratio of surfactant to foam suppressor is about 10 to 1 to 1 to 1.

3. A composition according to Claim 1 wherein the total concen-tration of tripolyphosphate, silicate and carbonate is at least about 20%.

4. A composition according to Claim 3 wherein the concentration of tripolyphosphate is about 20 to 30%.

5. A composition according to Claim 1 wherein the tripolyphosphate comprises a mixture of the substantially anhydrous and hexa-hydrate forms thereof in a corresponding weight ratio of about 1:2 to 2:1.

6. A composition according to Claim 5 wherein said weight radio is about 1:1.

7. A composition according to Claim 1 further containing a tint-ing amount of dyestuff.

8. A composition according to Claim 1, wherein said thickener is a smectite and/or attapulgite clay.

9. A composition according to Claim 1 wherein said surfactant is an alkali metal C8 to C14 alkyl diphenyl oxide sulfonate.

10. A composition according to Claim 1 wherein said tripolyphos-phate is a sodium tripolyphosphate; said carbonate is sodium carbonate; said surfactant is a mixture of mono- and di-(C8 to C14 alkyl) diphenyl oxide disulfonates and said thickening agent is bentonite.

11. A composition according to claim 10 having a pH of 10.5 to about 13.5.

12 A composition according to Claim 10 having a pH of about 11.5 to about 12.7.

13. A composition according to Claim 10 having a thixotropy index of about 6 to 8.