CA1128401A

CA1128401A - Detergent compositions

Info

Publication number: CA1128401A
Application number: CA336,796A
Authority: CA
Inventors: Hermann Rabitsch
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1978-10-03
Filing date: 1979-10-02
Publication date: 1982-07-27
Also published as: ZA795231B; AU5136179A; JPS5550096A; JPS6131751B2; EP0009953B1; EP0009953A1; BR7906347A; DE2965209D1; AU533317B2; ES484666A1; ATE3056T1

Abstract

cC.1034 Abstract of the Disclosure Particulate fabric washing detergent compositions are made with mixed phosphate detergency builders which comprise at least 5% of discrete particles of a water-soluble alkali metal polymer phosphate and at least 2% of an alkali metal orthophosphate in the ratio of 10:1 to 1:5 parts by weight, the total amount of these phosphates being from 10%
to 40% of the composition and not more than 10% of other phosphate builders being present. The compositions are conveniently made by spray-drying a base powder and then admixing the polymer phosphate in discrete particle form with the base powder.

Description

~.~21~
- 1 ~ c~.~03 DETERGENT CO~OSITIONS
.

The present invention relates to powdered detergent compositions which are adapted ~or fabric washing, and which contain synthetic detergent active compounds together with mixed phosphate aetergency builders~ ~he invention eoncerns in particular the production o~ detergent compositions which eontain levels of the mixed phosphate detergency builders which ean be lower than conventional phosphate builder le~els, but which still retain good detergency properties.
~ceording to the present invention, a particul~te detergent composition based on mi~ed phosphate detergency builders comprises a synthetic anionic, nonionic, amphoteric or zwitterionic detergent compound or mixture thereof~ an alkali metal orthophosphate, and diserete particles of alkali me-tal or ammonium polymer phosphate.
, ~2~
~2- cC.1034 The invention includes a process for the preparation of the detergent composition, which comprises forming a detergent base powder containing some or all of the detergent active compound or compounds and optionally some of the alkali metal orthophosphate, and admixing an alkali metal or ammonium polymer phosphate in discrete particulate form with the base powder. Preferably the base powder is prepared by spray drying in the normal way using conventional equipment and process conditions. However, other conventional techniques may be used for preparing the base powder containing some or all of the detergent active compound or com-pounds and of the alkali metal orthophosphate. Other heat-sens-itive ingredients may be admixed with the base powder together r~ith or separately from the alkali metal or ammonium polymer phosphate, for example oxygen bleach compounds such as sodium perborate.

In UK patent No. 1,530,799 we described powdered fabric washing detergent compositions which essentially contain mixed alkali metal tripolyphosphate and alkali metal orthophosphate detergency builders in the ratio of from 10:1 to 1:5 parts by weight. These compositions were found to have surprisingly good detergency properties though containing lower levels'of the phosphate detergency builders than in conventional sodium tripolyphosphate-based detergent compositions. This development enabled either a reduction in manufacturing cost because the difference in phos,phate content could be made up with a cheaper filler, or an improvement in overall detergency by adding extra bleach or other additive instead. Additionally, this development facilitated the achievement of decreased phosphorus levels in '~

detergent products to meet present or expected leyislation.
Products of the type described in our aforementioned patent, have already met with apprecia~le commercial success, especially as economy brands. However, one potential problem which has been found with the detergent compositions based'on mixed alkali metal tripolyphosphate, and orthophosphate builders, is the level of inorganic deposits which are sometimes found on washed fabrics and to a lesser extent surfaces in washing machines, expecially heater elements. he present invention is directed to decreasing the level of such deposits whilst retaining benefits of good detergency building properties~
Whilst not wishing to be bound by theory, it appears that the partial or complete replacement of the sodium tripolyphosphate, in the detergent compositions of our aforementioned patent by the alkali metal or a~monium polymer phosphate gives less inorganic deposition on the washed fabrics, because the polymer phosphate has a decreased tendency to degrade to alkali metal pyrophosphate during the washing process. Also, adding some and preferably all or at least a major part of the polymer phosphate to the detergent composition is discrete particulate form, as distinct from in-cluding the polymer phosphate in a spray dried base powder, avoids the degradation of the polymer phosphate during spray drying which would form more alkali metal pyrophosphate. We have found that the presence in the detergent composition of such alkali metal pyrophosphate contributes paricularly to inorganic deposits on the washing machines. By avoiding or substantially decreasing the initial presence of alkali metal pyrophosphate, and taking steps to hinder its formation during ~\~

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the washing process itself, it appears possible now to control inorganic deposition on fabrics and washing machine sur~aces better than hitherto, and yet still achieve good detergency building at relatively low phosphate levels.
The alkali metal polymer phosphate used in the compositions of the invention is preferably sodium polymer phosphate, but if desired the potassium or ammonium salts can be used. For con-venience the term alkali metal polymer phosphate is used below and in the claims to include the sodium, potassium and ammonium salts. The alkali metal polymer phosphates are generally re-presented as having the formula M2O(~PO3)n, where M is sodium, potassium or ammonium and _ is an integer which is at least 4 and ~p to about 100 or more, preferably from about 6 to about 50. In the case of the preferred sodium polymer phosphates, these figures correspond to a P2O5 content of at least about 60.4% by weight up to a theoretical maxiumum of about 69.6%, preferably about 63%
to about 69% P2O5 by weight of the polymer phosphates. To be effective the p~lymer phosphates must of course be water-soluble.
It should be appreciated that the chemical structures of the polymer phosphates are not precisely defined, and some degree of ring formation or branching may be \, ~z~
5 _ oC.103~

present in the otherl~ise normally linear polymer strwcture, especially with the shorter polyl~er chain lengths. ~he polymer phosphates are sometimes also l~own as glassy phos-phates or Graha~'s salt.
It is preferred that all or at least a major part o~
the alkali metal polymer phosphc~te should be admiYed with the detergen-t base po~Yder, ie postdosed, to obtain the most bene:Cit of lo~er alkali metal pyrophosphate content i~n the product. ~owever, some alkali metal polymer phosphate can be included in the base powder if desired, and this can help -to improve the powder properties, particularly when relatively low alkali me-tal orthophospha-te levels are used. The alkali metal polymer phosphate which is pos-tdosed should, of course, have a suitable particulate ~orm ~or post-~5 dosing, that is to say lt should have an appropriate particlesize range and powder density for uniform mixing with the base powder, so as to avoid undue segregation in the finished product.
The alkali metal orthophosphate used is either potassium or pre~erably sodium orthophosphate, as the latter is oheaper and more readily available. Normally the tri alkali metal salts are used, but orthophosphoric acid or the di- or mono-alkali metal salts, eg disodium hydrogen orthophosphate or monosodium dihydrogen orthophosphate could be used i~ desired in the production o~ the compositions. In the la~ter evsn~
other more alkaline salts should also be presen-t to maintain a high pH in the end product, ie with ~ull neutralisation to

2~34~L
- 6 - cc~103~

-the -triall~ali metal or-thophosphc~te salts. The use of a mix-ture of the monosodi~ dihydrogen ancl disodiutn hydrogen orthophosphc~tes in the r~-tio of 1:3 to 2:3, especially abou-t i:2, is par-ticularly adv~ntageous, as such a mi~ture (known as kiln-feed) is made in the productio~ of sodiu~ tripoly-phosphate and is rea~ily available. I-t is pre~erred to have all the alkali metal orthophosphate present in the detergent base powder, eg by inclusion in ~n aqueous detergent slurry and then spray dried, but part of the orthophosphate can be postdosed i:E desired, either separately or together ~rith the alkali metal pol~ner phosphate~
The alkali metal orthophosphate can be used in the form of the anhydrous or hydrated salts, bu^t in the former case it is preferred to promote hydration during processing, eg by adding the anhydrous orthophosphate to a detergent slurry and spray drying to form the base powder. ~he alkali metal polymer phospha-tes do not form hydrated salts as such, and are normally used in anhydrous form, bu-t they are hygrosc~pic and tend to absorb atmospheric moisture. ~he amou~ts o~ the salts used are expressed in anhydrous form.
The total amoun-ts of the essential alkali metal polymer phosphate and alkali metal orthophosphate, and any other phosphates whlch may be present in the detergent compositions, are chosen according to the overall detergency builder level which is desired in the detergent compositions or according to the maximum permit-ted phosphorus content.
Normally the total phosphate builder :level, which is ~2B~

preferably derived solely from alkali metal polymer phos?hate and alkali metal orthophosphate, is between about 10~ and about 40%, by weight of the composition, preferably with an amount of at least about 5~ and at least about 2~ up to about 20% each of the alkali metal polymer phosphate and orthophosphate, respectively.
Preferably the amounts of the alkali polymer phosphate and alkali metal orthophosphate are each from about 5~ to about 15%, espccia;ly about 5% to 10~, b-,~ Tois t of th~ cor~sitLon. 'lhe total amount of alkali metal polymer phosphate and alkali metal orthophosphate is preferably from about 10% to about 25%, especially about 15% to about 20%, by weight of the composition.
It is preferred to have amounts of the alkali metal polymer ~phosphate and the alkali metal orthophosphate generally within the ratio of from about 3:1 to about 1:3, especially about 2:1 to about 1:2, parts by weight, respectively. These ratios of polymer phosphate to orthophosphate are particularly suitable for detergent compositions used at relatively high product concentrations, ie 0.3% to 0.8~ by weight, as is common practice in Europe, especially in front-loading automatic washing machines, and where moderate levels of phosphates are allowed in the products, ie equivalent to about 3% to 7~ P.
It is preferable that the only phosphate detergency builders used to make the compositions of the invention should be the alkali metal polymer phosphate and ~lZ~34f~ 1 alkali metal orthophosphate. In particular, it is desirahle to add no alkali metal, ie sodium or potassium, pyrophosphates to the compositions as they tend to increase inoryanic deposition as mentioned above. It is also preferred not to have any alkali metal tripolyphosphate present because of the relative ease with which it hydrolyses to form the alkali metal pyrophosphate.
~owever, some alkali metal tripolyphosphate may be present if desired either in the base powder or postdosed thereto, for example because of its beneficial effect on the base powder pro-perties or because of its relative cheapness. But for optimum detergency in relation to total phosphate content, it is pre-ferred to have not more than about 10% by weight of other alkali metal phosphate builders, and especially not more than about 5%
of tripolyphosphate present in the detergent composition.
Some tripolyphosphate and pyrophosphate are also generally found as impurities at low levels in other commercial alkali metal phosphates, and some tripolyphosphate and pyrophosphate may be f~rm~d by hydrolysis of any polymer phosphate during processing, especially if some of it is present in the slurry rather than being all postdosed. Hence, total absence of alkali metal tri-polyphosphate and pyrophosphate is generally unattainable in the detergent compositions. It is particularly preferred to have not more than about 2.5% of alkali metal pyrophosphate present in the compositions, as at higher levels the amounts of inorganic deposits on the washing machine parts become significantly more noticeable.

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9 CC.103~

The detergent compositions of the inven-tiorl necessarily incl~lde from about 2.5% -to about 50%~ preEerably about 5% to abou~
30%~ ancl especially about 10% to abollt 25~o~ by weigh-t o e a synthetic anionic, nonionic, ampho-teric or zwitterionic detergent compo~md or mi.~ture thereof. Many suitable detergen-t compounds are commercially available and are ~ully described in the li-terature, for example in ~'Surface ~ctive ~genbs and Detergents", Volumes I and II, by Schwartz, Perry ~ Berch.
The preferred detergent compounds which can be used are synthe-tic anionic and nonionic compounds. ~he former are usually water-soluble alkali metal salts of organic sulphates and sulphona-tes having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to inclucle '15 the alkyl portion of higher acyl radicals. Examples o~
suitable synthe-tic anionic de-tergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher ~G~-C18) alcohols produced for example ~rom tallow or coconut oil; sodium and potassium alh~l (C9-C
2b benzene sulphonates, par-ticularly sodium linear secondary alhyl (C1v-Cl5) benzene sulphonates; 'sodium alhyl glyceryl '' ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium coconu-t oil fa~ty 2~ monoglyceride sulphates and sulphonàtesi sodium and potassium salts of sulphuric acid esters O:e higher (Cg-Cl8) fatty alcohol-alkylene o~ide,'particularly ethylene o~ide, - - -...

~Z8~
- 10 - cC.103~

reac-tion prodncts; the reaction products O:e ~'at-ty acids such as coconut fat-ty acids esteri:eied l~ith ise-thionic acid and neutralised with sodillm hydroxicle; sodium c~nd potassium sal-ts of fat-ty acid ~ides o~ methyl taurine; alkane mono~
sulphonates such as those derived by reac-ting alpha-ole~ins (C8-C20) with sodi~ bisulph:i-te and -those derived by reacting para~fins with S02 ~nd Cl~ ana then hydrolysing with a base to produce a random sulphonate; and olefin sulphonates, which term is used to describe the material made by reacting olefins, particularly C10-C20 alpha ole~ins, with S03 and then neutralising and hydrolysing t,he reac-tion product. ~he preferred anionic detergent compounds are sodium (C11-C15) alkyl ben~ene sulphon~tes and sodium (Cl~j-C18) all~i sulphates. ' ''' Suitable nonionic detergent compo-~mds which may be used include in particular the reaction products o~ compounds having a hydrophobic group and a reactive hydrogen atom, ~or example aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Speçi~ic nonionic detergent compounds are alkyl (C6-C22) phenol-ethylene o~ide condensates, generally 5 to 25 E0, ie 5 t,o 25 units o~
ethylene o~ide per molecule, the condensation products o~
aliphatic (C8-Cl&) primary or secondary linear or branched alcohols with et,hylene o~ide, generally 6 ~o 30 E0, :or wi-th bo-th ethylene and propylene oxide,and produc-ts made by condensation of ethylene oxide wi-th -the reaction products of propylene oxide and e-thylenedia~ine.

. ____ . _ ._.. _ ., .. , .. , , . .... .. . .. , , . . _ .. ,. ,.. ....... ... , ... ,,, .. . . ,.. . . ,, . , ~ . . ... . . . ... .. . .......

~ c~.103~

Qther so~called nonionic detergen-t compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxiaes c~nd dialkyl sulphoxides.
Mi~tures o~ de-tergent compourlds, :for example mixed S anionic or mixed anionic and nonionic compounds may be used in the de-tergent compositions, par-ticularly in -the lat-ter case to provide controlled low sudsing properties. This is bene~icial ~or compositions intended ~or use in suds-intoler-ant automatic washing machines. We have also found tha-t the use of some nonionic detergent compounds in the compositions decreases the tendency o~ insoluble phosphate salts to deposit on the washed fabrics, especially when used in admixture with some soaps as described below.
~mounts of amphoteric or ~witterionic detergent compounds can also be used in the composi-tions o~ the invention but this is not normally desired due to their reIatively high cost. If any amphoteric or zwitterionic detergent compounds are used it is generally in small amounts in compositions - based on the much more commonly used synthetic anionic and/or nonionic detergent compounds. For example, mixtures of amine oxides and ethoxylated nonionic detergent compounds can be used.
Soaps may also be present in the detergent compositions o~ the invention, but not as the sole detergent compounds.
~he soaps are particularly use~ul at low levels in binary and ternary mixtures, toge-ther with nonionic or mixed synthetic anionic and nonionic detergent compolmds, which have low - l2 ~ cC.103~

sudsing prop~rties. 'rhc soaps which are used are the sodium, or less desira~ly potassiu~ sal-ts oI C10_C2~ f~tty acids. I-t is particulc~r~Ly preferred -tha-t the soaps should be based mainly on ~the longer chain fa-tty acids ~ thin -this 5 range, -that is with a-t leas-t hal:e O:e tlie soaps having a carbon chain length of 16 or over. This is most con~enien-t-ly accomplished by using soaps from natural sources sucll as tallow, palm oil or rapeseed oil, which can be hardened if desired, with lesser ~lo~ts O:e other shorter chain soaps, preparecl from nut oils such as coconut oil or palm kernel oil. The amount of such soaps can be va-ried bet~een about 0. 5% and about 25% by weight, with lower amounts of abou-t 0. 5% to about 5% being generally sufficient for lather control. ~noun-ts of soap bètween about 2% ~nd abou-t 20%, especially between about 5yo and about 15%, can advantageously be used to give a beneficial effect on detergency.
Apart from the essential de-tergent compounds and detergency builders, the detergent composi-tions of the invention can con-tain any of the conventional additives in the amounts in which such materials are normally employed in fabric ~ashing detergent compositions. Examples of these additives include lather boos-ters such as alkanolamides, particularly the monoethanolamides derived from palm kernel fatty acids and coconu-t fa-tty acids, lather depressants such as alkyl phospha~es, wa~es and silicones, antiredepositlon agents such as sodium carbo~ymethylcëllulose and polyvinyl pyrrolidone optionally copolymerised with vinyl acetate, ~., .. .. _... .. . . .... .. . ..

- 13 ~ ~.103~

oxygen-releasing bleaching agen-ts such ~s sodium perbora-te and sodium percarbon~te, per-acid bleach precwrsers, chlorine-releasing bleaching agen-ts such as trichloroisocyan-uric acid and alkali metal salts of dichloroisocyanuric acid?
fabric softening agents, inorganic salts such as sodium sulpha-te, soclium carbonate and magnesium silicate, and, usually present in very minor amoun-ts, fLuorescent agents, perf~es, enzymes such as proteases and amylaseq, germicides and colourants.

. , . . . . ........... . . , . . ..... .. _ _ .. . . .. ... .
It is particularly beneficial to include in the detergent compositions an ~nount of sodium perborate, pre~erably between ~ .` r - .. . .
about 1~o and abou~ 40%, for e~ample abou-t 1~% to about 300k, by weigh-t. It has been found -that the blear,hing action of sodium perborate is boosted under the highly alkaline conditions which also give optimum detergency building action for the alkali metal orthophosphate. Thus, it becomes possible to achieve improved bleaching properties by using the same ~evels of sodiu~ perborate as normal; or decreasad levels of sodium-perborate can be used to give equal bleaching properties to those o~ conventional products wl-th higher levels of perborate and sodium tripolyphosphate as the sole detergency builder. The latter option can also be used to ~urther decrease the raw materials costs o~ the , _ .
compositlons; if à chèa ~iller;is,used in place of~part o~

the sodium perborate.

It is desirable to include one or more antideposition agents in the detergent compositions o~ the invention, to ~Z8~
- cC.103~

decrease th~ tende:ncy -to :eorm inorg,~nic depo.sits on washed ~abrics. It appears -that the ef.tective anti-leposition agents are materials ~ ich s-tabilise insolub].e calcium orthophospha-te par-ticles and thereby inhibi-t their deposition onto the fabrics. ~he most effec-tive antidepo-sition agents are anionic polyelec-troly-tes, especially polymeric aliphatic carboxylates. The amount of any such antideposition agent can be from abou-t 0. 01% -to abou-t 10% of the compositions, bu-t is normally from about 0.1% to a~ou-t 5% by l~eight, preferably ~rom about 0. 2% to about 2% by weight of the compositions.
Specific preferred antideposition agen-ts are the alkali.
metal or ammonium, preferably the sodi~, salts o~ homo-:and co-polymers o~. acrylic acid or substi-tuted acrylic acids, such as sodium polyacrylate, the sodium salt of copolymeth-acrylamide/acrylic acid and sodium poly-alpha-hydroxyacrylate, salts of copolymers of maleic anhydride with ethylene,acrylic acid, vinylmethylether or styrene, especially l:l copolymers~ and optionally with partial esterification of the carboxyl groups. Such copolymers preferably have relatively low molecular weights, eg in the range of about l,OOO to 50,000.
Other antideposition agents include thè sodium salts of poly-.
maleic acid, polyitaconic acid and polyaspartic acid, phosphate esters of ethoxylated aliphatic alcohols, poly-ethylene glycol phosphate esters, a~d certain organic;phosphonicacids or salts thereof ~uch as sodium ethane-1-h~droxy~ diphos-phonate, sodiu~ ethyle~eliamine tetramethylene phosphonate and ~Z8~ cC.'103~

sodiwn-2-phosphollo~u-tarLe tricarboxylate. Mixtures of organic acids or substitu-tecl acrylic acids or the:ir salts wi-th protec-tive colloids such as gela-tin may also be used. r~he most preferred an~ideposi-tion agent are sodium polyacrylates ha~ing a MW of abou-t 10,000 -to 50,000, for example about 20,000 -to ~0,000.
Detergent compositions which are based on mixed phosphate builders and incorporate an alkali metal orthophosphate arld aIkali metal polymer phospha-te -together wi-th an an-tideposi-tion agent are described in our copending UK patent applica-tion ~9071~78 of even date.
It is also possible to include in the de-tergent compositions of -the invention minor amounts, preferably no-t more than about 20% by weight, of o-ther non-phosphate detergency builders, which may be either so-called precipltant builders, ion-exchange or sequestrant builders. ~his is of particular benefit where it is desired to increase detergency whilst using particularl~ low levels of the essential alkali metal polymer phosphate and alkali metal orthophosphate builders, so as to achieve especially low phosphorus conte~ts in the detergent compositions. Examples of such other detergency builders are amine carboxylates such as sodium nitrilotriacetate~ sodium carbonate, sodium aluminosillcate ion-excha~ge materials such as zeolites A and X, sodium citrate and soap, which can function as a detergency builder, as discussed above.
However, such other builder materials are not essential and it is a particular benefit of using the mixed alkali metal poly~er phosphate and orthophosphate that s~tis~actQry detergency properties ca~ be achieved at lower total phosphate levels than hitherto considered necessary without other detergency builders.

. ' ~z~
l~ cC.~03~

I-t is generally also desirable to include in the compo-sitions an ~nount of an alkali me-tal silicate, par-ticularly sodi~ or-tho-, meta- or preferably neutral or alkaline silicalte. The presence of such alkali metal silicates at levels of at least about 1%, and preferably from about 5% to about 15%, by weigh-t of the compositions, is advantageous in decreasing the corrosion of metal parts in washing machines, besides giving processing benefi-ts and generally improved po~lder properties. The morê highly alkaline ortho- and meta-silicates would normally only be used at lower amoun-ts within this range, in admixture with the neu-tral or alkaline silicates.
The compositions of the inven-tion are required to be alkaline, but not too,strongly alkaline as this could result in fabric damage and also be hazardous for domestic usage.
In prac-tice the composi-tions should give a p~ of from 9 to 11 in use in aqueous wash solution. It is preferred in particular for domes-tic products to have a minimum-p~ of at least 9.25 and especially a p~ o~ 9.5 or over, as lower pEs tend to be less effective for optimum detergency building, and a ma~imum pH of 10.5, as more highly alkaline products can be hazardous if misused. The pH is measured at the lowest normal usage concentration of 0.1~ w/~ of the product in water of 12H (Ca), (French permanent hardness, calcium only) at 50C so that a ~qatisfactory degree o~ alkalinity can be assured in use at all normal product concentra~ions.' r . .

~L~2~
_ l7 _ c~.103 ~ he pE O:r thc de-tergent Gomposit-ions in use is controlled by the ~nount of alkali metal orthophosphate and any other alkaline salts such as alkali metal silicate, sodiwn perbora-te ~ld sodium carbonate present. 'rhe presence of such other alkaline salts, especially the alkali metal silicates, is particularly beneficial, because the alkalinity of the alkali metal orthophosphate is diminished in hard water due to precip:itation o~ the calcium salt. In addition the alkali metal polymer phosphate is more stable and resistant to hydrolysis under highly alkaline conditions. The o-ther ingredients in the alkaline detergent compositions of the inven-tion should of course be chosen ~or alkaline stability, especially the pE sensit-ve materials such as enzymes.
~he detergent compositions of the invention are in particulate form after admixture of the spray dried base powder and the alkali metal polymer phosphate.
~owever, if desired the detergent compositions may be compressed or compacted into tablets or blocks, or otherwlse treated for e~ample by granulation, prior to packaging a~d sale. Because of the hygroscopic nature of the alkali metal polymer phosphates, it may be desirable to use moisture impermeable packaging for the detergent compositions, for e~ample in plastic or fabric sache-ts containing pre-measured doses for washing machine usage.
The invention is illustrated by the following Examplesin which parts and percentages are by weight except where otherwise indicated.

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~lZ8~
- .L8 - cc~103 Ex~mples 1 to 9 ~ series of detergent powde:rs were prepared by firstly spray drying a detergen-t base powder to the following formulation:
Ingredient~ (based on :Einal product) Sodium alkyl benzene 9 sulphonate Nonionic detergent compound1 Sodium orthophosphate S
Sodium silicate 10 (Na20:SiO2, 1:2) Magnesium silica~e 0.5 Sodium sulphate 27.2 Water and minor additives 9.3 65.0 C1~-C15 alcohol - 18 E0 condensate.
~mounts o~ additives as specified in the Table below were then adaed to this base powder to ma~e the ~ormulations as ~ollows: :

In~redient Ex: 1 2 3 ~ 5 6 7 8 9 Base powder 65 ~
Sodium poly~er ~ 10 - ~ 10 ~ - 10 phosphate 25~ Sodium poly~er - 10 ~ - 10 ~ - 10 phosphate Sodium poly~er - 10 - - 10 - - 10 phosphate--Sodium polyacrylate5 - - - 2 2 a 30 Sodium sulpha~e 2 2 2 (con-tinued ov~r~

, .. , .. , . ~. _ . . . . ~i Z84~.
- 19 - cc.103 (continued) Ingredient ~x: 1 2 3 ~ S 6 7 8 9 _ Sodi~n perborate 20 - -Nonionic detergent 2 ~ >

5 Enzyme and perfume 0.~ - ->

Lather controller6 O. 6 Polymer chain length 6-8.

3 Polymer chain length 15-20 (plus 0. 36% NaOEI for pH
control).
~ Polymer chain length 25-30 (plus 0, 72% NaO~ for pH
control).

Versicol E7. (MW 27,000) 6 ~lkyl phosphate.

These detergent compositions were evaluated for washing . . . ~, performance, including especially inorganic deposition on fabrics. The tests were accomplished in laundrometer machines using a product concentration of 8 g/l in water of - ~0 French hardness at 95C. ~he levels of deposition an the fabrics were de-termined after 10 repeat wash cycles using standard fabrics as indicated.

- ~0 inor~anic dep~sition Fabric- Ex:1 2 3 ~ 5 6 7 8 9 , __ _ _ _ _ _ _ _ _ Cotton poplin 0.6 0.5 0.7 0.2 0.2 0.2 0.3 0.1 0,2 Polyester/cotton 0.5 1.0 1.0 0.2 0.2 0.2 0.2 0.2 0,2 blend ~50:SO) Unsi~ed cotton 1.8 2.0 2.1 0.6 0.3 0.2 0.8 0~3 0.3 1:12t3401 cc. 1034 'rhese re~uLts a~e ~ood in cor~lp~rison with o-ther reduced phosphate builder products, and show especially -the benefit of using polyacryla-te ln conj~c-tion with the or-tho-phospha-te polymer phosphate builder mixture. ~ compara-tive produc-t with 12% sodium tripolyphosphate ins-tead of the polymer phospha-te and with no polyacryla-te gave 1.8%~ 2.9yo and 6.0%
deposition on the same f`abrics, respectively, under the same tes-t conditions~
Exam~e 10 A detergen-t composition was prep æed to the following formulation by dry mixing the ingredients to which -the p æticulate sodium polymer phosphate was added :
In~redient %
Sodium alkyl benzene sulphonate 6 15 Nonionic detergent compounds (mixed L~
alcohol-12 and 18 ~0) Sodium polymer phosphate (~hain 6 length 18) Sodium orthophosphate 6 20 Sodium silicate 12 Sodium c æboxymethyl cellulose Sodium polyacrylate (MW 30,000) 2 Sodium ~sulphate ~
Sodium perborate - 22 25 Water + minor additives to 100 The composition was tested for detergency and inorganic deposition o~ washed fabrics (ash). Considering the low phosphate builder level the detergency properties were good, and the ash levels were particularly low, being 0.5% on cotton poplin fabric and 1.5% on Krefeld cotton after 10 wash cycles.

~,~z~9~o~ cC.103~1 '~he -tes-ts were conducted a-t a p:roduct concen-tra-tion of 8g/1 in an Atlas launderome-ter at 95C in 23GII wa-ter. By wa-y of comparison, the ash levels for a similar sodium tripolyphosphate-sodium-orthophosphate buil-t f`ormulation were 2.0% and 5.7%
respectively, under -the same conditions.
ExamE~es 11-14 ~ our detergent compositions were made -to -the formula-tion below:
Ingredient %
Sodium aIkylbenzene sulphona-te 7 ~onionic detergent compounds (12-18E0) 5 Sodium or-thophospha-te 6.0 Sodium polymer phosphate1 (chain length 18) 10.0 15 Sodium silicate -12.0 Sodium sulphate 28.0 Antideposition agent1~2 2.0 Sodium perborate 22 W~ter and minor additives to 100 Added in particulate form to the dry-mixed base powder - 2In Example 11 - Sodium polyacrylate (MW27000) 12 - Ethylene diamine. tetra methylene phosphonic acid " .13 - Polyhydrox~ acrylic acid " 15 - Polymaleic acid (MW 1400) lhese compositions were evaluated for detergency and inorga~ic fabric deposition, and found to be good in both respect. ~he average figures for the latter on differen-t cotton types af-ter 10 wash cycles were only 0.3%, 0.65%, 0.75% and 1.3~, respectively, under -the same conditions as for Example 10.

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- 22 - ~ ~fZ8~ cc.10~

Simi.lar reslllts were also achieved when sodi~n ethane-1-hyc~roxy-1, 1-diphosphonate and o-ther molecular weigh-t po].y-acryla-tes were used as an-tideposi.tion agents in the formula-tions.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A particulate alkaline detergent comp-osition comprising from about 2.5% to about 50%
by weight of a synthetic anionic, nonionic, amphot-eric or zwitterionic detergent compound or mixture thereof, a-t least about 5% by weight of discrete particles of water-soluble alkali metal polymer phosphate having the formula M20-(MP03)n wherein M
is alkali metal and n is an integer of at least 4, and at least about 2% by weight of an alkali metal orthophosphate, the ratio of the polymer phosphate to the orthophosphate being from about 10:1 to about 1:5 parts by weight, the total amount of -the alkali metal .
polymer phosphate and alkali metal orthophosphate being from about 10% to about 40% by weight of the composition and not more than about 10% of other alkali metal phosphate builders being in the composition.

2. A detergent composition according to claim 1, wherein the alkali metal polymer phosphate is in sodium salt form.

3. A detergent composition according to claim 1 wherein in the formula of the alkali metal polymer phosphate n is from about 6 to about 50.

4. A detergent composition according to claim 1 wherein the amount of alkali metal polymer phosphate is from about 5% to about 15% by weigh-t of the composition.

5. A detergent composition according to claim 1 wherein the alkali metal orthophosphate is trisodium orthophosphate, disodium monohydrogen orthophosphate, monosodium dihydrogen orthophosphate or a mixture thereof.

6. A detergent composition according to claim 1 wherein the amount of alkali metal ortho-phosphate is from about 5% to about 15% by weight of the composition.

7. A detergent composition according to claim 1 wherein the total amount of the alkali metal polymer phosphate and of the alkali metal ortho-phosphate is from about 10% to about 25% by weight of the composition.

8. A detergent composition according to claim 1 wherein the ratio by weight of alkali metal polymer phosphate to alkali metal orthophosphate is from about 3:1 to about 1:3.

9. A detergent composition according to claim l comprising not more than about 5% by weight of alkali metal tripolyphosphate.

10. A detergent composition according to claim l comprising not more than about 2.5% by weight of alkali metal pyrophosphate.

11. A detergent composition according to claim 1 comprising from about 0.1% to 10% by weight of an anti-deposition agent which is an anionic polyelectrolyte.

12. A detergent composition according to claim 11 wherein the anti-deposition agent is a polymeric aliphatic carboxylate.

13. A detergent composition according to claim 11 wherein the anti-deposition agent is an organic phosphonic acid or a salt thereof.

14. A detergent composition according to claim 12 wherein the polymeric aliphatic carboxylate is sodium polyacrylate.

15. A detergent composition according to claim 11 wherein the amount of the anti-diposition agent is from about 0.1% to about 5% by weight of the composition.

16. A detergent composition according to claim 1 comprising from about 0.5% to about 25% by weight of soap.

17. A detergent composition according to claim 1 comprising from about 10% to about 40% by weight of sodium perborate or percarbonate.